US20040183961A1 - Display device - Google Patents
Display device Download PDFInfo
- Publication number
- US20040183961A1 US20040183961A1 US10/813,194 US81319404A US2004183961A1 US 20040183961 A1 US20040183961 A1 US 20040183961A1 US 81319404 A US81319404 A US 81319404A US 2004183961 A1 US2004183961 A1 US 2004183961A1
- Authority
- US
- United States
- Prior art keywords
- optical switching
- scanning signal
- light emitting
- display device
- signal light
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/133362—Optically addressed liquid crystal cells
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/135—Liquid crystal cells structurally associated with a photoconducting or a ferro-electric layer, the properties of which can be optically or electrically varied
- G02F1/1354—Liquid crystal cells structurally associated with a photoconducting or a ferro-electric layer, the properties of which can be optically or electrically varied having a particular photoconducting structure or material
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
- G02F1/1362—Active matrix addressed cells
- G02F1/1368—Active matrix addressed cells in which the switching element is a three-electrode device
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2300/00—Aspects of the constitution of display devices
- G09G2300/04—Structural and physical details of display devices
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
- G09G3/3611—Control of matrices with row and column drivers
- G09G3/3648—Control of matrices with row and column drivers using an active matrix
Definitions
- the present invention relates to a display device, and more particularly to a display device in which an optical switching element is provided in each of a plurality of pixels.
- a thin film transistor is widely used as a switching element in active matrix type display devices.
- a plurality of TFTs are formed in a matrix pattern on a TFT substrate.
- the TFT substrate includes scanning signal lines for applying scanning signals to the TFTs, and data signal lines for applying data signals thereto.
- the scanning signal lines and the data signal lines extend in the respective directions that cross each other (typically perpendicular to each other). Therefore, at each intersection therebetween, a scanning signal line and a data signal line, which are made of a conductive material such as a metal, oppose each other via an insulative film therebetween, thus forming a capacitor. Such a capacitor formed at each intersection causes a signal delay, thereby adversely influencing the display.
- Japanese Laid-Open Patent Publication No. 1-173016 and Japanese Laid-Open Patent Publication No. 4-367826 each disclose a liquid crystal display device including an optical switching element provided in each pixel, and a scanning signal light emitting element for emitting light as a scanning signal to the optical switching element.
- a scanning signal light emitting element which is a linear light emitting element or a linear light guide element having a light emitting element at an end thereof, functions as a scanning signal line in a conventional TFT substrate. Therefore, the unnecessary capacitor as described above is not formed, thereby preventing a signal delay.
- a display device in which an optical switching element is provided in each pixel as those liquid crystal display devices described above has a problem, so called “crosstalk phenomenon”.
- a crosstalk phenomenon is caused when light emitted from a scanning signal light emitting element that is associated with an optical switching element is incident on a different, unintended optical switching element.
- Japanese Laid-Open Patent Publication No. 10-288965 discloses an organic EL display device including a pin hole mask, which transmits only a portion of light emitted from scanning signal light emitting elements that travels straight toward optical switching elements, in order to suppress the occurrence of a crosstalk phenomenon.
- the present inventor has found that the use of a pin hole mask may not always prevent light from being incident on an unintended optical switching element depending on the arrangement of the optical switching elements and the scanning signal light emitting elements, in which case the occurrence of a crosstalk phenomenon is not suppressed sufficiently.
- a crosstalk phenomenon may be caused also by light from the backside light source.
- the present invention has been made to solve the problems as set forth above, and has an object to provide a display device capable of displaying an image with a high quality while suppressing the occurrence of a signal delay and a crosstalk phenomenon.
- a first display device of the present invention includes: a plurality of pixel electrodes defining a plurality of pixels that are arranged in a matrix pattern; optical switching elements electrically connected to the plurality of pixel electrodes, respectively; and scanning signal light emitting elements for emitting dotted light, as scanning signals, to the optical switching elements, wherein a distance between the optical switching element and the scanning signal light emitting element is less than a pixel pitch at which the plurality of pixels are arranged.
- a second display device of the present invention includes: a plurality of pixel electrodes defining a plurality of pixels that are arranged in a matrix pattern; optical switching elements electrically connected to the plurality of pixel electrodes, respectively; scanning signal light emitting elements for emitting dotted light, as scanning signals, to the optical switching elements; and a louver provided between the optical switching element and the scanning signal light emitting element.
- a third display device of the present invention includes: a plurality of pixel electrodes defining a plurality of pixels that are arranged in a matrix pattern; optical switching elements electrically connected to the plurality of pixel electrodes, respectively; scanning signal light emitting elements for emitting dotted light, as scanning signals, to the optical switching elements; and a focusing element provided between the optical switching element and the scanning signal light emitting element for focusing light emitted from the scanning signal light emitting element on a predetermined area.
- the focusing element may be a lens.
- the display device may further include: a backlight provided on a side away from the optical switching element with respect to the scanning signal light emitting element; and a light blocking layer provided on a side of the scanning signal light emitting element that is closer to the backlight.
- light emitted from the scanning signal light emitting element is modulated into a predetermined polarized state, and substantially only light that is in the predetermined polarized state is incident on the optical switching element.
- a fourth display device of the present invention includes: a plurality of pixel electrodes defining a plurality of pixels that are arranged in a matrix pattern; optical switching elements electrically connected to the plurality of pixel electrodes, respectively; and scanning signal light emitting elements for emitting dotted light, as scanning signals, to the optical switching elements, wherein light emitted from the scanning signal light emitting element is modulated into a predetermined polarized state, and substantially only light that is in the predetermined polarized state is incident on the optical switching element.
- the display device may further include: a first polarizing element provided between the optical switching element and the scanning signal light emitting element for modulating light emitted from the scanning signal light emitting element into the predetermined polarized state; and a second polarizing element provided between the first polarizing element and the optical switching element and arranged so as to selectively transmit light that is in the predetermined polarized state.
- the display device may further include: at least one counter electrode opposing the plurality of pixel electrodes; and a liquid crystal layer provided between the plurality of pixel electrodes and the at least one counter electrode.
- the display device may further include: at least one counter electrode opposing the plurality of pixel electrodes; and an organic electroluminescence material layer provided between the plurality of pixel electrodes and the at least one counter electrode.
- the display device further includes a light blocking layer provided on a viewer side of the optical switching element.
- the scanning signal light emitting element is formed in a dot-like shape.
- a fifth display device of the present invention includes: a plurality of pixel electrodes defining a plurality of pixels that are arranged in a matrix pattern; optical switching elements electrically connected to the plurality of pixel electrodes, respectively; and scanning signal light emitting elements, respectively associated with the optical switching elements, for emitting light, as scanning signals, to the optical switching elements, wherein the scanning signal light emitting element is formed in a dot-like shape, and substantially only light that is emitted from one scanning signal light emitting element that is associated with one optical switching element is incident on the optical switching element.
- a distance between one optical switching element and one scanning signal light emitting element that is associated with the optical switching element may be less than a pixel pitch at which the plurality of pixels are arranged.
- the display device may further include a louver between at least one optical switching element and at least one scanning signal light emitting element that is associated with the at least one optical switching element.
- the display device may further include a focusing element between at least one optical switching element and at least one scanning signal light emitting element that is associated with the at least one optical switching element for focusing light emitted from the at least one scanning signal light emitting element on a predetermined area.
- the focusing element may be a lens.
- the display device may further include: a backlight provided on a side away from the optical switching element with respect to the scanning signal light emitting element; and a light blocking layer provided on a side of the scanning signal light emitting element that is closer to the backlight.
- each scanning signal light emitting element is modulated into a predetermined polarized state, and substantially only light that is in the predetermined polarized state is incident on one optical switching element that is associated with the scanning signal light emitting element.
- the display device may further include: a first polarizing element provided between at least one optical switching element and at least one scanning signal light emitting element that is associated with the at least one optical switching element for modulating light emitted from the at least one scanning signal light emitting element into the predetermined polarized state; and a second polarizing element provided between the first polarizing element and the at least one optical switching element and arranged so as to selectively transmit light that is in the predetermined polarized state.
- the display device may further include: at least one counter electrode opposing the plurality of pixel electrodes; and a liquid crystal layer provided between the plurality of pixel electrodes and the at least one counter electrode.
- the display device may further include: at least one counter electrode opposing the plurality of pixel electrodes; and an organic electroluminescence material layer provided between the plurality of pixel electrodes and the at least one counter electrode.
- the display device further includes a light blocking layer provided on a viewer side of the optical switching element.
- the distance between the optical switching element and the scanning signal light emitting element is less than the pixel pitch at which the plurality of pixels are arranged, thereby preventing light emitted from a scanning signal light emitting element in one pixel from being incident on an unintended optical switching element in an adjacent pixel.
- the occurrence of a crosstalk phenomenon is suppressed, and an image is displayed with a high quality.
- the second display device of the present invention includes a louver provided between the optical switching element and the scanning signal light emitting element, whereby light that is emitted obliquely from the scanning signal light emitting element is blocked by the louver. Therefore, light that is emitted obliquely from a scanning signal light emitting element in one pixel is prevented from being incident on an unintended optical switching element in an adjacent pixel. Thus, the occurrence of a crosstalk phenomenon is suppressed, and an image is displayed with a high quality.
- the third display device of the present invention includes a focusing element provided between the optical switching element and the scanning signal light emitting element for focusing light emitted from the scanning signal light emitting element on a predetermined area.
- a focusing element provided between the optical switching element and the scanning signal light emitting element for focusing light emitted from the scanning signal light emitting element on a predetermined area.
- the fourth display device of the present invention light emitted from the scanning signal light emitting element is modulated into a predetermined polarized state, and substantially only light that is in the predetermined polarized state is incident on the optical switching element. Therefore, light that is not in the predetermined polarized state is prevented from being incident on the optical switching element. Thus, the occurrence of a crosstalk phenomenon due to light that is not from the scanning signal light emitting element (e.g., light from a backlight in a liquid crystal display device) is suppressed, and an image is displayed with a high quality.
- the scanning signal light emitting element e.g., light from a backlight in a liquid crystal display device
- the scanning signal light emitting element is formed in a dot-like shape, and substantially only light that is emitted from a scanning signal light emitting element that is associated with an optical switching element is incident on the optical switching element. Therefore, the power supplied to the scanning signal light emitting element is efficiently used as scanning signal light, thereby reducing the power consumption. Moreover, light emitted from unintended scanning signal light emitting elements (light emitting elements other than the scanning signal light emitting element that is associated with the optical switching element) will not be incident on the optical switching element, thereby suppressing the occurrence of a crosstalk phenomenon.
- the present invention provides a display device capable of displaying an image with a high quality while suppressing the occurrence of a signal delay and a crosstalk phenomenon.
- the present invention can suitably be used with a liquid crystal display device or an organic EL display device.
- FIG. 1 is a cross-sectional view schematically illustrating a liquid crystal display device 100 of Embodiment 1 of the present invention.
- FIG. 2A is a plan view schematically illustrating a substrate 100 c provided in the liquid crystal display device 100 of Embodiment 1 of the present invention.
- FIG. 2B is an enlarged view illustrating an area 2 B encircled by a broken line in FIG. 2A.
- FIG. 2C is a cross-sectional view taken along line 2 C- 2 C′ in FIG. 2B.
- FIG. 2D is a cross-sectional view taken along line 2 D- 2 D′ in FIG. 2B.
- FIG. 3A is a diagram illustrating an angular distribution of light emitted from a scanning signal light emitting element 42 in a case where an air layer exists between the scanning signal light emitting element 42 and an optical switching element 14 .
- FIG. 3B is a diagram illustrating an angular distribution of light emitted from the scanning signal light emitting element 42 in a case where an air layer does not exist between the scanning signal light emitting element 42 and the optical switching element 14 .
- FIG. 4 is a cross-sectional view schematically illustrating a liquid crystal display device 600 in which the distance between the optical switching element 14 and the scanning signal light emitting element 42 is equal to or greater than the pixel pitch.
- FIG. 5 is a cross-sectional view schematically illustrating a liquid crystal display device 200 of Embodiment 2 of the present invention.
- FIG. 6 is a cross-sectional view schematically illustrating a liquid crystal display device 300 of Embodiment 3 of the present invention.
- FIG. 7 is a cross-sectional view schematically illustrating a focus lens used as a focusing element 45 provided in the liquid crystal display device 300 of Embodiment 3 of the present invention.
- FIG. 8 is a cross-sectional view schematically illustrating a liquid crystal display device 400 of Embodiment 4 of the present invention.
- FIG. 9 is a cross-sectional view schematically illustrating an organic EL display device 500 of an alternative embodiment of the present invention.
- FIG. 10 is a cross-sectional view schematically illustrating an organic EL display device 500 ′ of an alternative embodiment of the present invention.
- FIG. 11A is a plan view schematically illustrating a light guide element 42 ′′ for emitting dotted light.
- FIG. 11B is an enlarged view illustrating an area 11 B encircled by a broken line in FIG. 11A.
- FIG. 11C is a cross-sectional view taken along line 11 C- 11 C′ in FIG. 11B.
- the present inventor has conducted an in-depth study on the use of an optical switching element as a switching element to be provided in each pixel, and has found that it is preferred that the optical switching element and the scanning signal light emitting element are sufficiently separated from each other. This will be discussed in greater detail below.
- scanning signal lines are required for applying scanning signals to the organic EL elements.
- the scanning signal lines and data signal lines for applying data signals to optical switching elements are provided so as to cross each other, thereby forming a capacitor at each intersection therebetween. Therefore, a signal delay may occur due to such a capacitor, thereby adversely influencing the display quality.
- a large distance can be provided between the data signal lines and the scanning signal light emitting elements, i.e., the optical switching elements and the scanning signal light emitting elements can be sufficiently separated from each other, so that the capacitance value of a capacitor formed at each intersection therebetween is so small that the adverse influence thereof on the display quality is negligible.
- the capacitor as described above is not formed in a case where the scanning signal light emitting element is, for example, a combination of a cold-cathode tube and an optical waveguide, it is still preferred that the optical switching elements and the scanning signal light emitting elements are sufficiently separated from each other. Specifically, it is preferred that the scanning signal light emitting elements are provided on a substrate that is different from a substrate on which the optical switching elements are formed, or on the same substrate on which the optical switching elements are formed, but on a side of the substrate on which the optical switching elements are not formed. By providing the scanning signal light emitting elements in such a manner, the yield of the display device improves.
- the optical switching elements and the scanning signal light emitting elements are sufficiently separated from each other in view of the signal delay suppression and/or the production yield.
- light emitted from a scanning signal light emitting element generally has a certain angle of divergence (a certain angular distribution)
- a crosstalk phenomenon is more likely to occur as the distance between the optical switching element and the scanning signal light emitting element is increased.
- Japanese Laid-Open Patent Publication No. 10-288965 discloses suppressing a crosstalk phenomenon by providing a pin hole mask between the optical switching elements and the scanning signal light emitting elements, but fails to disclose findings as those above on the distance between the optical switching element and the scanning signal light emitting element. In fact, even if a pin hole mask is used, a crosstalk phenomenon is not suppressed sufficiently in some cases. This is because the essential effect of the use of a pin hole mask is merely a reduction in the size of the scanning signal light emitting element.
- FIG. 1 is a cross-sectional view schematically illustrating a liquid crystal display device 100 , which is a display device of Embodiment 1 of the present invention.
- the liquid crystal display device 100 is an active matrix type liquid crystal display device in which a plurality of pixels are arranged in a matrix pattern.
- the liquid crystal display device 100 includes a plurality of pixel electrodes 12 defining a plurality of pixels, optical switching elements 14 electrically connected to the pixel electrodes 12 , respectively, and scanning signal light emitting elements 42 for emitting dotted light, as scanning signals, to the optical switching elements 14 .
- the distance between the optical switching element 14 and the scanning signal light emitting element 42 is less than the pixel pitch, at which the plurality of pixels are arranged.
- the liquid crystal display device 100 includes an active matrix substrate 100 a and a color filter substrate 100 b opposing each other, with a liquid crystal layer 30 being provided therebetween.
- the active matrix substrate 100 a includes a transparent substrate (e.g., a glass substrate or a polymer film) 10 , the pixel electrodes 12 , the optical switching elements 14 electrically connected to the pixel electrodes 12 , respectively, and data signal lines (source lines) 16 for supplying data signals to the optical switching elements 14 .
- the pixel electrodes 12 are formed in a matrix pattern on the transparent substrate 10 by using a transparent conductive material (e.g., ITO).
- the optical switching elements 14 are made of, for example, CdS, Se, ZnO or amorphous Si.
- the optical switching element 14 When the optical switching element 14 is irradiated with light, electrons and carriers are generated by the optical energy of the light, and thus the resistance value of the optical switching element 14 decreases, whereby the optical switching element 14 is turned into a conductive state, i.e., turned ON.
- the color filter substrate 100 b is provided on the viewer side of the active matrix substrate 100 a, and includes a transparent substrate (e.g., a glass substrate or a polymer film) 20 , a color filter layer 22 , a light blocking layer 24 and a counter electrode 26 .
- the color filter layer 22 , the light blocking layer 24 and the counter electrode 26 are provided on one side of the transparent substrate 20 that is closer to the liquid crystal layer 30 .
- the counter electrode 26 is formed by using a transparent conductive material (e.g., ITO) and, in the present embodiment, is a single common electrode opposing a plurality of pixel electrodes.
- a transparent conductive material e.g., ITO
- alignment layers e.g., horizontal alignment layers
- polarizing plates 19 and 29 are provided on the back side (the side opposite to the viewer side) of the active matrix substrate 100 a and on the viewer side of the color filter substrate 100 b, respectively.
- the liquid crystal display device 100 further includes an additional substrate 100 c provided on the back side of the active matrix substrate 100 a, and a backlight 50 provided on the back side of the substrate 100 c.
- the substrate 100 c includes a transparent substrate (e.g., a glass substrate) 40 , a light blocking layer 41 provided on the viewer side of the transparent substrate 40 , and the scanning signal light emitting element 42 provided on the light blocking layer 41 .
- the light blocking layer 41 may be, for example, a metal layer (about 100 nm thick) such as an aluminum layer or a silver layer, a black resin layer (about 1 ⁇ m thick), or a layered structure of a chromium layer (about 100 nm thick) and a chromium oxide layer (about 100 nm thick).
- FIG. 2A is a plan view schematically illustrating the substrate 100 c of the liquid crystal display device 100
- FIG. 2B is an enlarged view illustrating an area 2 B encircled by a broken line in FIG. 2A
- FIG. 2C is a cross-sectional view taken along line 2 C- 2 C′ in FIG. 2B
- FIG. 2D is a cross-sectional view taken along line 2 D- 2 D′ in FIG. 2B.
- the scanning signal light emitting element 42 includes a reflection electrode (e.g., an aluminum layer having a thickness of about 100 nm) 61 formed in a stripe shape on the transparent substrate 40 , a light emitting layer (an organic electroluminescence material layer) 62 formed on the reflection electrode 61 , an insulating layer 63 formed on the reflection electrode 61 , and a transparent electrode (e.g., an ITO layer having a thickness of about 150 nm) 64 formed on the light emitting layer 62 and the insulating layer 63 .
- a reflection electrode e.g., an aluminum layer having a thickness of about 100 nm
- a light emitting layer an organic electroluminescence material layer
- insulating layer 63 formed on the reflection electrode 61
- a transparent electrode e.g., an ITO layer having a thickness of about 150 nm
- the light emitting layer 62 provided between the reflection electrode 61 and the transparent electrode 64 is formed in a dot-like shape at a position corresponding to the optical switching element 14 , and the insulating layer 63 is formed so as to surround the dot-shaped light emitting layer 62 .
- One optical switching element 14 is provided for each pixel, and one scanning signal light emitting element 42 is provided for each optical switching element 14 .
- the stripe-shaped reflection electrode 61 is provided for each row of pixels, for example, and a plurality of scanning signal light emitting elements 42 belonging to one row of pixels together function as a scanning signal line (gate line) 42 ′.
- the liquid crystal display device 100 having such a structure, first, dotted light, as scanning signals, is emitted from the scanning signal light emitting elements 42 to the optical switching elements 14 , whereby the optical switching elements 14 are turned ON in a line sequential manner.
- data signals display signals
- data signals are supplied from the data signal lines 16 to the optical switching elements 14 , whereby a voltage according to a data signal is applied to the pixel electrode 12 of each pixel via the optical switching element 14 .
- a predetermined voltage is applied to the counter electrode 26 opposing a plurality of pixel electrodes 12 , and the orientation of liquid crystal molecules of the liquid crystal layer 30 changes according to the voltage (potential difference) between each pixel electrode 12 and the counter electrode 26 so as to modulate light from the backlight 50 according to the change in the orientation, thereby displaying an image.
- the distance between the scanning signal light emitting element 42 and the optical switching element 14 is less than the pixel pitch, at which the plurality of pixels are arranged. In other words, the distance between the scanning signal light emitting element 42 and the optical switching element 14 is less than the arrangement pitch of the optical switching elements 14 . This is because the arrangement pitch of the optical switching elements 14 , which are provided one in each pixel, is typically substantially equal to the pixel pitch.
- the light intensity (light intensity per unit area) at a particular point in the plane along which the optical switching elements 14 are arranged is in proportion to (cos ⁇ ) 2 , where ⁇ is the angle of a straight line extending between the particular point and the scanning signal light emitting element 42 with respect to another straight line extending between the scanning signal light emitting element 42 and the optical switching element 14 that is associated with the scanning signal light emitting element 42 . Accordingly, the intensity of light emitted from a scanning signal light emitting element 42 that is incident on a point where ⁇ >45° is less than one half of the intensity of light that is incident on the optical switching element 14 associated with the scanning signal light emitting element 42 .
- the optical switching elements 14 are arranged so that adjacent optical switching elements 14 are each located at a point where ⁇ >45°, it can be considered that scanning signal light is substantially not incident on the adjacent optical switching element 14 . Therefore, even in a case where an air layer does not exist, if the distance between the scanning signal light emitting element 42 and the optical switching element 14 is less than the arrangement pitch of the optical switching elements 14 , light is prevented from being incident on an adjacent optical switching element 14 .
- the distance between the optical switching element 14 and the scanning signal light emitting element 42 is less than the pixel pitch at which the plurality of pixels are arranged, whereby light emitted from the scanning signal light emitting element 42 is prevented from being incident on the optical switching element 14 of an adjacent pixel.
- the occurrence of a crosstalk phenomenon is suppressed, and an image is displayed with a high quality.
- each pixel in which the optical switching element 14 is provided, typically has a generally rectangular shape, whereby the repeating pitch of the pixels in the longitudinal direction of the pixel may be different from that in the width direction of the pixel. Therefore, the arrangement pitch of the optical switching elements 14 in the longitudinal direction of the pixel may also be different from that in the width direction of the pixel. In order to more reliably suppress the occurrence of a crosstalk phenomenon, it is preferred that the distance between the scanning signal light emitting element 42 and the optical switching element 14 is less than the pixel pitch in the width direction of the pixel. It is possible to provide a large distance between the scanning signal light emitting element 42 and the optical switching element 14 if the width direction of the pixel is parallel to the scanning lines.
- the liquid crystal display device 100 of Embodiment 1 of the present invention includes the light blocking layer 41 , which is provided on one side of the scanning signal light emitting element 42 that is closer to- the backlight 50 .
- the light blocking layer 41 is provided on one side of the scanning signal light emitting element 42 that is closer to- the backlight 50 .
- each scanning signal light emitting element 42 is formed in a dot-like shape in the liquid crystal display device 100 , the power supplied to the scanning signal light emitting element 42 is efficiently used as scanning signal light, thereby reducing the power consumption.
- liquid crystal display device 600 in which the distance between the optical switching element 14 and the scanning signal light emitting element 42 is equal to or greater than the pixel pitch, as illustrated in FIG. 4, light emitted from the scanning signal light emitting element 42 may be incident on the optical switching element 14 of an adjacent pixel to cause a crosstalk phenomenon.
- the liquid crystal display device 600 illustrated in FIG. 4 has substantially the same structure as that of the liquid crystal display device 100 of Embodiment 1, except that the distance between the optical switching element 14 and the scanning signal light emitting element 42 is equal to or greater than the pixel pitch.
- FIG. 5 is a cross-sectional view schematically illustrating a liquid crystal display device 200 , which is a display device of Embodiment 2 of the present invention.
- a liquid crystal display device 200 which is a display device of Embodiment 2 of the present invention.
- elements having substantially the same functions as those of the liquid crystal display device 100 of Embodiment 1 are denoted by the same reference numerals and will not be further described below.
- the distance between the optical switching element 14 and the scanning signal light emitting element 42 may be either less than the pixel pitch (as in the liquid crystal display device 100 of Embodiment 1) or equal to or greater than the pixel pitch.
- the liquid crystal display device 200 includes a louver 44 provided between the optical switching element 14 and the scanning signal light emitting element 42 .
- the louver 44 blocks light that is emitted obliquely from the scanning signal light emitting element 42 .
- the louver 44 is an optical element including a plurality of light blocking walls that are formed generally parallel to the straight line extending between the scanning signal light emitting element 42 and the optical switching element 14 associated therewith. In the present embodiment, the louver 44 is provided immediately on the scanning signal light emitting element 42 .
- the liquid crystal display device 200 of Embodiment 2 of the present invention includes the louver 44 provided between the optical switching element 14 and the scanning signal light emitting element 42 , whereby light that is emitted obliquely from the scanning signal light emitting element 42 is blocked by the louver 44 . Therefore, light emitted from a scanning signal light emitting element 42 is prevented from being incident on an unintended optical switching element 14 adjacent to an optical switching element 14 that is associated with the scanning signal light emitting element 42 . Thus, the occurrence of a crosstalk phenomenon is suppressed, and an image is displayed with a high quality.
- FIG. 6 is a cross-sectional view schematically illustrating a liquid crystal display device 300 , which is a display device of Embodiment 3 of the present invention. While the liquid crystal display device 200 of Embodiment 2 includes the louver 44 for blocking light that is emitted obliquely from the scanning signal light emitting element 42 , the liquid crystal display device 300 of Embodiment 3 includes a focusing element 45 for focusing light emitted from the scanning signal light emitting element 42 on a predetermined area.
- elements having substantially the same functions as those of the liquid crystal display device 200 of Embodiment 2 are denoted by the same reference numerals and will not be further described below.
- the liquid crystal display device 300 of Embodiment 3 includes the focusing element 45 provided between the optical switching element 14 and the scanning signal light emitting element 42 .
- the focusing element 45 focuses light emitted from the scanning signal light emitting element 42 on a predetermined area.
- the focusing element 45 is provided immediately on the scanning signal light emitting element 42 of the substrate 100 c.
- the focusing element 45 may be, for example, a focusing lens 45 including a transparent resin layer 45 a, tapered reflection surfaces 45 b provided in the transparent resin layer 45 a so as to surround the scanning signal light emitting element 42 , and lens sections 45 c each provided over the scanning signal light emitting element 42 surrounded by the tapered reflection surfaces 45 b, as illustrated in FIG. 7.
- the focusing lens 45 as illustrated in FIG. 7 In a case where the focusing lens 45 as illustrated in FIG. 7 is provided, light that is emitted with a certain angular distribution (i.e., divergently emitted light) from the scanning signal light emitting element 42 is collimated by the tapered reflection surface 45 b, and focused on a predetermined area by the lens section 45 c. For example, light emitted from the scanning signal light emitting element 42 is focused on an area that coincides with the optical switching element 14 that is associated with the scanning signal light emitting element 42 .
- a certain angular distribution i.e., divergently emitted light
- the liquid crystal display device 300 of Embodiment 3 of the present invention includes the focusing element 45 provided between the optical switching element 14 and the scanning signal light emitting element 42 for focusing light emitted from the scanning signal light emitting element 42 on a predetermined area. Therefore, light emitted from a scanning signal light emitting element is focused on a predetermined area, whereby the light emitted from the scanning signal light emitting element is prevented from being incident on an optical switching element in an adjacent pixel. Thus, the occurrence of a crosstalk phenomenon is suppressed, and an image is displayed with a high quality.
- FIG. 6 illustrates an arrangement where the polarizing plate 19 , one of a pair of polarizing plates, is provided on the back side of the active matrix substrate 100 a
- the polarizing plate 19 may alternatively be provided on the back side of the substrate 100 c.
- the focusing element 45 as described above is provided, substantially no decrease in the display quality due to light emitted from the scanning signal light emitting element 42 is observed even if the polarizing plate 19 is provided on the back side of the substrate 100 c.
- the focusing element 45 is not limited to the focusing lens 45 including the tapered reflection surface 45 b and the lens section 45 c combined together, as illustrated in FIG. 7, but may alternatively be a focusing lens including a pin hole mask and a lens section combined together.
- FIG. 8 is a cross-sectional view schematically illustrating a liquid crystal display device 400 of Embodiment 4 of the present invention.
- elements having substantially the same functions as those of the liquid crystal display devices 200 and 300 of Embodiments 2 and 3 are denoted by the same reference numerals and will not be further described below.
- the liquid crystal display device 400 of Embodiment 4 has a structure such that light emitted from the scanning signal light emitting element 42 is modulated into a predetermined polarized state, and substantially only light that is in the predetermined polarized state is incident on the optical switching element 14 .
- the liquid crystal display device 400 includes a first polarizing element 72 provided between the optical switching element 14 and the scanning signal light emitting element 42 , and a second polarizing element 74 provided between the first polarizing element 72 and the optical switching element 14 .
- a polarizing plate 19 ′ i.e., one of the pair of polarizing plates 29 and 19 ′ of the liquid crystal display device 400 that is on the side closer to the backlight 50 , is provided on the back side of the substrate 100 c.
- the first polarizing element 72 modulates light emitted from the scanning signal light emitting element 42 into a predetermined polarized state. Moreover, the second polarizing element 74 is arranged so that light that is in the predetermined polarized state is selectively transmitted therethrough.
- each of the first polarizing element 72 and the second polarizing element 74 is an absorption type polarizing element that transmits linearly-polarized light of a particular polarization direction while absorbing linearly-polarized light whose polarization direction is perpendicular to the particular polarization direction.
- the first polarizing element 72 and the second polarizing element 74 are arranged so that the transmission axis directions thereof are parallel to each other.
- the first polarizing element 72 and the second polarizing element 74 are arranged so that the transmission axis directions thereof are perpendicular to the transmission axis direction of the polarizing plate 19 ′ on the backlight side.
- the liquid crystal display device 400 of Embodiment 4 has a structure such that light emitted from the scanning signal light emitting element 42 is modulated into a predetermined polarized state, and substantially only light that is in the predetermined polarized state is incident on the optical switching element 14 , whereby light from the backlight 50 is prevented from being incident on the optical switching element 14 .
- the occurrence of a crosstalk phenomenon due to light from the backlight 50 is suppressed, and an image is displayed with a high quality.
- the occurrence of a crosstalk phenomenon is suppressed by using the polarization selectivity of a polarizing element, thereby providing a higher effect of suppressing the occurrence of a crosstalk phenomenon due to light from the backlight 50 , as compared with a structure where the light blocking layer 41 is used, as in the liquid crystal display devices 100 , 200 and 300 of Embodiments 1, 2 and 3.
- first polarizing element and the second polarizing element are not limited to a polarizing element as illustrated in the present embodiment, but may alternatively be an absorption type polarizing element that contains a dye (e.g., iodine), or a reflection type polarizing element.
- a dye e.g., iodine
- Reflection type polarizing elements that can be used in the present invention include, for example, DBEF (manufactured by SUMITOMO 3M Limited), which transmits polarized light of a particular polarization direction while reflecting polarized light whose polarization direction is perpendicular to the particular polarization direction, or a polarizing element made of a cholesteric liquid crystal material, which only transmits either left or right circularly-polarized light while reflecting the other circularly-polarized light.
- DBEF manufactured by SUMITOMO 3M Limited
- a polarizing element made of a cholesteric liquid crystal material which only transmits either left or right circularly-polarized light while reflecting the other circularly-polarized light.
- the distance between the optical switching element 14 and the scanning signal light emitting element 42 may be set to be less than the pixel pitch as in the liquid crystal display device 100 of Embodiment 1; a louver may be provided between the optical switching element 14 and the scanning signal light emitting element 42 as in the liquid crystal display device 200 of Embodiment 2; or a focusing element may be provided between the optical switching element 14 and the scanning signal light emitting element 42 as in the liquid crystal display device 300 of Embodiment 3.
- FIG. 9 is a cross-sectional view schematically illustrating the organic EL display device 500 , which is a display device of an alternative embodiment of the present invention.
- the organic EL display device 500 includes a first substrate 500 a and a second substrate 500 b provided on the back side of the first substrate 500 a.
- the first substrate 500 a includes a transparent substrate (e.g., a glass substrate or a polymer film) 80 , a plurality of pixel electrodes 82 , optical switching elements 84 electrically connected to the pixel electrodes 82 , respectively, data signal lines 86 for supplying data signals to the optical switching elements 84 , an organic EL material layer 83 provided on each pixel electrode 82 , and a counter electrode (e.g., an aluminum layer) 85 opposing the pixel electrode 82 via the organic EL material layer 83 .
- the pixel electrodes 82 are formed in a matrix pattern on the transparent substrate 80 by using a transparent conductive material (e.g., ITO).
- the first substrate 500 a further includes a light blocking layer 87 provided on the viewer side of the optical switching element 84 , a transparent insulating layer (e.g., an SiO 2 layer having a thickness of about 150 nm) 88 provided on the optical switching element 84 and the data signal line 86 , and a transparent conductive layer (e.g., an ITO layer) 89 provided so as to cover the transparent insulating layer 88 and the counter electrode 85 .
- the counter electrodes 85 opposing the respective pixel electrodes 82 are electrically connected to one another by the transparent conductive layer 89 , and together function as a single counter electrode opposing the pixel electrodes 82 .
- the second substrate 500 b includes a transparent substrate (e.g., a glass substrate or a polymer film) 90 , and scanning signal light emitting elements 92 provided on the transparent substrate 90 .
- the scanning signal light emitting element 92 may be, for example, an organic EL element as illustrated in FIG. 2B to FIG. 2D.
- Embodiments 1 to 3 of the present invention may also be used with the organic EL display device 500 illustrated in FIG. 9.
- the distance between the optical switching element 84 and the scanning signal light emitting element 92 may be set to be less than the pixel pitch as in the liquid crystal display device 100 of Embodiment 1; a louver may be provided between the optical switching element 84 and the scanning signal light emitting element 92 as in the liquid crystal display device 200 of Embodiment 2; or a focusing element may be provided between the optical switching element 84 and the scanning signal light emitting element 92 as in the liquid crystal display device 300 of Embodiment 3.
- the light blocking layer 87 is provided on the viewer side of the optical switching element 84 , whereby light emitted from the scanning signal light emitting element 92 to the optical switching element 84 is prevented from being transmitted to the viewer side.
- a reduction in the contrast ratio is suppressed.
- the organic EL display device with which the present invention can suitably be used is not limited to the organic EL display device 500 as illustrated in FIG. 9, but may alternatively be, for example, an organic EL display device 500 ′ as illustrated in FIG. 10.
- the organic EL display device 500 ′ illustrated in FIG. 10 includes a first substrate 500 a ′, and a second substrate 500 b ′ provided on the back side of the first substrate 500 a′.
- the first substrate 500 a ′ includes a transparent substrate (e.g., a glass substrate or a polymer film) 80 ′, a single counter electrode 85 ′ formed on the transparent substrate 80 ′ by using a transparent conductive material (e.g., ITO), an organic EL material layer 83 ′ provided on the counter electrode 85 ′, a transparent insulating layer (e.g., an SiO 2 layer having a thickness of about 150 nm) 88 ′ provided on the counter electrode 85 ′, a plurality of pixel electrodes (e.g., an aluminum layer) 82 ′ formed in a matrix pattern and opposing the counter electrode 85 ′ via the organic EL material layer 83 ′, optical switching elements 84 ′ electrically connected to the pixel electrodes 82 ′, respectively, and data signal lines 86 ′ for supplying data signals to the optical switching elements 84 ′.
- the first substrate 500 a ′ further includes a light blocking layer 87 ′ provided on the viewer side of the optical
- the second substrate 500 b ′ includes a transparent substrate (e.g., a glass substrate or a polymer film) 90 ′, and scanning signal light emitting elements 92 ′ provided on the transparent substrate 90 ′.
- the scanning signal light emitting element 92 ′ may be, for example, an organic EL element as illustrated in FIG. 2B to FIG. 2D.
- Embodiments 1 to 3 of the present invention may also be used with the organic EL display device 500 ′ having such a structure so as to suppress the occurrence of a crosstalk phenomenon.
- the present invention can suitably be used with liquid crystal display devices and organic EL display devices.
- the thickness of an active matrix substrate of a liquid crystal display device is currently 500 ⁇ m to 700 ⁇ m, and the pixel pitch of a liquid crystal display device is currently 200 ⁇ m to 800 ⁇ m. Therefore, it is often the case with a liquid crystal display device that the distance between the optical switching element and the scanning signal light emitting element is equal to or greater than the pixel pitch.
- the occurrence of a crosstalk phenomenon can be suppressed by setting the distance between the optical switching element and the scanning signal light emitting element to be less than the pixel pitch, by providing a louver, or by providing a focusing element, as in Embodiments 1 to 3.
- a backlight is provided on the back side of the device, whereby light from the backlight may be incident on the optical switching element.
- the occurrence of a crosstalk phenomenon due to light from a backlight can be suppressed by providing a light emitting layer on the backlight side of the scanning signal light emitting element as in Embodiments 1 to 3, or by utilizing the polarization selectivity of a polarizing element as in Embodiment 4.
- the distance between the optical switching element and the scanning signal light emitting element may not be necessary to provide a substrate between scanning signal light emitting elements and optical switching elements. Therefore, it is easy to set the distance between the optical switching element and the scanning signal light emitting element to be less than 200 ⁇ m to 300 ⁇ m, i.e., a distance with which the occurrence of a crosstalk phenomenon is generally prevented and to be greater than about 1 ⁇ m at which a signal delay becomes problematic.
- a scanning signal light emitting element that emits dotted light may be a combination of a light emitting element that emits light in a linear or planar pattern with a pin hole mask, or a combination of a light guide element 42 ′′ as illustrated in FIG. 11A, FIG. 11B and FIG. 11C with a light source.
- FIG. 11A is a plan view schematically illustrating the light guide element 42 ′′
- FIG. 11B is an enlarged view illustrating an area 11 B encircled by a broken line in FIG. 11A
- FIG. 11C is a cross-sectional view taken along line 11 C- 11 C′ in FIG. 11B.
- the light guide elements 42 ′′ are provided in a stripe pattern on the substrate 100 c, as illustrated in FIG. 11A, and a light source (e.g., a cold-cathode tube; not shown) is provided at an end of each light guide element 42 ′′.
- a light source e.g., a cold-cathode tube; not shown
- the light guide element 42 ′′ includes depressions 42 a ′′, each of which is formed on the back side surface of the light guide element 42 ′′ in a dot-like shape so as to correspond to the optical switching element of each pixel.
- the shape of the depression 42 a ′′ is, for example, a conical shape as illustrated in FIG. 11B and FIG. 11C.
- Light which has been emitted from the light source and has entered the light guide element 42 ′′, travels through the inside of the light guide element 42 ′′ while being totally reflected repeatedly by the side surfaces of the light guide element 42 ′′, as illustrated in FIG. 11C. Some of the light traveling through the inside of the light guide element 42 ′′ is reflected by the depression 42 a ′′. Such light is incident on the viewer-side side surface at an angle such that the light is not totally reflected, and thus comes out of the light guide element 42 ′′. In this way, the light guide element 42 ′′ functions as a scanning signal light emitting element that emits dotted light, as scanning signals, to the optical switching elements.
- scanning signal light emitting elements are provided on a substrate that is different from a substrate on which optical switching elements are provided
- the present invention is not limited to this arrangement of the scanning signal light emitting elements.
- the scanning signal light emitting elements may alternatively be provided on the same substrate on which the optical switching elements are provided, but on a side of the substrate on which the optical switching elements are not provided.
Abstract
A display device of the present invention includes: a plurality of pixel electrodes defining a plurality of pixels that are arranged in a matrix pattern; optical switching elements electrically connected to the plurality of pixel electrodes, respectively; and scanning signal light emitting elements for emitting dotted light, as scanning signals, to the optical switching elements. The distance between the optical switching element and the scanning signal light emitting element is less than the pixel pitch at which the plurality of pixels are arranged.
Description
- 1. Field of the Invention
- The present invention relates to a display device, and more particularly to a display device in which an optical switching element is provided in each of a plurality of pixels.
- 2. Description of the Background Art
- In recent years, various types of display devices have been developed in the art, such as liquid crystal display devices and organic EL (electroluminescence) display devices. Particularly, active matrix type display devices, in which a switching element is provided in each of a plurality of pixels, have been actively developed in the art.
- A thin film transistor (TFT) is widely used as a switching element in active matrix type display devices. A plurality of TFTs are formed in a matrix pattern on a TFT substrate. The TFT substrate includes scanning signal lines for applying scanning signals to the TFTs, and data signal lines for applying data signals thereto.
- The scanning signal lines and the data signal lines extend in the respective directions that cross each other (typically perpendicular to each other). Therefore, at each intersection therebetween, a scanning signal line and a data signal line, which are made of a conductive material such as a metal, oppose each other via an insulative film therebetween, thus forming a capacitor. Such a capacitor formed at each intersection causes a signal delay, thereby adversely influencing the display.
- In order to prevent a signal delay by the formation of such an unnecessary capacitor, it has been proposed in the art to employ, as a switching element, an optical switching element that is turned ON by being irradiated with light.
- For example, Japanese Laid-Open Patent Publication No. 1-173016 and Japanese Laid-Open Patent Publication No. 4-367826 each disclose a liquid crystal display device including an optical switching element provided in each pixel, and a scanning signal light emitting element for emitting light as a scanning signal to the optical switching element.
- In the liquid crystal display devices disclosed in these publications, a scanning signal light emitting element, which is a linear light emitting element or a linear light guide element having a light emitting element at an end thereof, functions as a scanning signal line in a conventional TFT substrate. Therefore, the unnecessary capacitor as described above is not formed, thereby preventing a signal delay.
- However, a display device in which an optical switching element is provided in each pixel as those liquid crystal display devices described above has a problem, so called “crosstalk phenomenon”. A crosstalk phenomenon is caused when light emitted from a scanning signal light emitting element that is associated with an optical switching element is incident on a different, unintended optical switching element.
- Japanese Laid-Open Patent Publication No. 10-288965 discloses an organic EL display device including a pin hole mask, which transmits only a portion of light emitted from scanning signal light emitting elements that travels straight toward optical switching elements, in order to suppress the occurrence of a crosstalk phenomenon.
- However, the present inventor has found that the use of a pin hole mask may not always prevent light from being incident on an unintended optical switching element depending on the arrangement of the optical switching elements and the scanning signal light emitting elements, in which case the occurrence of a crosstalk phenomenon is not suppressed sufficiently.
- Moreover, the present inventor has also found that in a display device including a backside light source, e.g., a liquid crystal display device including a backlight, a crosstalk phenomenon may be caused also by light from the backside light source.
- The present invention has been made to solve the problems as set forth above, and has an object to provide a display device capable of displaying an image with a high quality while suppressing the occurrence of a signal delay and a crosstalk phenomenon.
- A first display device of the present invention includes: a plurality of pixel electrodes defining a plurality of pixels that are arranged in a matrix pattern; optical switching elements electrically connected to the plurality of pixel electrodes, respectively; and scanning signal light emitting elements for emitting dotted light, as scanning signals, to the optical switching elements, wherein a distance between the optical switching element and the scanning signal light emitting element is less than a pixel pitch at which the plurality of pixels are arranged. Thus, the object set forth above is realized.
- A second display device of the present invention includes: a plurality of pixel electrodes defining a plurality of pixels that are arranged in a matrix pattern; optical switching elements electrically connected to the plurality of pixel electrodes, respectively; scanning signal light emitting elements for emitting dotted light, as scanning signals, to the optical switching elements; and a louver provided between the optical switching element and the scanning signal light emitting element. Thus, the object set forth above is realized.
- A third display device of the present invention includes: a plurality of pixel electrodes defining a plurality of pixels that are arranged in a matrix pattern; optical switching elements electrically connected to the plurality of pixel electrodes, respectively; scanning signal light emitting elements for emitting dotted light, as scanning signals, to the optical switching elements; and a focusing element provided between the optical switching element and the scanning signal light emitting element for focusing light emitted from the scanning signal light emitting element on a predetermined area. Thus, the object set forth above is realized.
- The focusing element may be a lens.
- The display device may further include: a backlight provided on a side away from the optical switching element with respect to the scanning signal light emitting element; and a light blocking layer provided on a side of the scanning signal light emitting element that is closer to the backlight.
- It is preferred that light emitted from the scanning signal light emitting element is modulated into a predetermined polarized state, and substantially only light that is in the predetermined polarized state is incident on the optical switching element.
- A fourth display device of the present invention includes: a plurality of pixel electrodes defining a plurality of pixels that are arranged in a matrix pattern; optical switching elements electrically connected to the plurality of pixel electrodes, respectively; and scanning signal light emitting elements for emitting dotted light, as scanning signals, to the optical switching elements, wherein light emitted from the scanning signal light emitting element is modulated into a predetermined polarized state, and substantially only light that is in the predetermined polarized state is incident on the optical switching element. Thus, the object set forth above is realized.
- The display device may further include: a first polarizing element provided between the optical switching element and the scanning signal light emitting element for modulating light emitted from the scanning signal light emitting element into the predetermined polarized state; and a second polarizing element provided between the first polarizing element and the optical switching element and arranged so as to selectively transmit light that is in the predetermined polarized state.
- The display device may further include: at least one counter electrode opposing the plurality of pixel electrodes; and a liquid crystal layer provided between the plurality of pixel electrodes and the at least one counter electrode.
- The display device may further include: at least one counter electrode opposing the plurality of pixel electrodes; and an organic electroluminescence material layer provided between the plurality of pixel electrodes and the at least one counter electrode.
- It is preferred that the display device further includes a light blocking layer provided on a viewer side of the optical switching element.
- It is preferred that the scanning signal light emitting element is formed in a dot-like shape.
- A fifth display device of the present invention includes: a plurality of pixel electrodes defining a plurality of pixels that are arranged in a matrix pattern; optical switching elements electrically connected to the plurality of pixel electrodes, respectively; and scanning signal light emitting elements, respectively associated with the optical switching elements, for emitting light, as scanning signals, to the optical switching elements, wherein the scanning signal light emitting element is formed in a dot-like shape, and substantially only light that is emitted from one scanning signal light emitting element that is associated with one optical switching element is incident on the optical switching element.
- A distance between one optical switching element and one scanning signal light emitting element that is associated with the optical switching element may be less than a pixel pitch at which the plurality of pixels are arranged.
- The display device may further include a louver between at least one optical switching element and at least one scanning signal light emitting element that is associated with the at least one optical switching element.
- The display device may further include a focusing element between at least one optical switching element and at least one scanning signal light emitting element that is associated with the at least one optical switching element for focusing light emitted from the at least one scanning signal light emitting element on a predetermined area.
- The focusing element may be a lens.
- The display device may further include: a backlight provided on a side away from the optical switching element with respect to the scanning signal light emitting element; and a light blocking layer provided on a side of the scanning signal light emitting element that is closer to the backlight.
- It is preferred that light emitted from each scanning signal light emitting element is modulated into a predetermined polarized state, and substantially only light that is in the predetermined polarized state is incident on one optical switching element that is associated with the scanning signal light emitting element.
- The display device may further include: a first polarizing element provided between at least one optical switching element and at least one scanning signal light emitting element that is associated with the at least one optical switching element for modulating light emitted from the at least one scanning signal light emitting element into the predetermined polarized state; and a second polarizing element provided between the first polarizing element and the at least one optical switching element and arranged so as to selectively transmit light that is in the predetermined polarized state.
- The display device may further include: at least one counter electrode opposing the plurality of pixel electrodes; and a liquid crystal layer provided between the plurality of pixel electrodes and the at least one counter electrode.
- The display device may further include: at least one counter electrode opposing the plurality of pixel electrodes; and an organic electroluminescence material layer provided between the plurality of pixel electrodes and the at least one counter electrode.
- It is preferred that the display device further includes a light blocking layer provided on a viewer side of the optical switching element.
- Functions of the present invention will now be described.
- In the first display device of the present invention, the distance between the optical switching element and the scanning signal light emitting element is less than the pixel pitch at which the plurality of pixels are arranged, thereby preventing light emitted from a scanning signal light emitting element in one pixel from being incident on an unintended optical switching element in an adjacent pixel. Thus, the occurrence of a crosstalk phenomenon is suppressed, and an image is displayed with a high quality.
- The second display device of the present invention includes a louver provided between the optical switching element and the scanning signal light emitting element, whereby light that is emitted obliquely from the scanning signal light emitting element is blocked by the louver. Therefore, light that is emitted obliquely from a scanning signal light emitting element in one pixel is prevented from being incident on an unintended optical switching element in an adjacent pixel. Thus, the occurrence of a crosstalk phenomenon is suppressed, and an image is displayed with a high quality.
- The third display device of the present invention includes a focusing element provided between the optical switching element and the scanning signal light emitting element for focusing light emitted from the scanning signal light emitting element on a predetermined area. Thus, light emitted from the scanning signal light emitting element is focused on the predetermined area. Therefore, light emitted from a scanning signal light emitting element in one pixel is prevented from being incident on an unintended optical switching element in an adjacent pixel. Thus, the occurrence of a crosstalk phenomenon is suppressed, and an image is displayed with a high quality.
- In the fourth display device of the present invention, light emitted from the scanning signal light emitting element is modulated into a predetermined polarized state, and substantially only light that is in the predetermined polarized state is incident on the optical switching element. Therefore, light that is not in the predetermined polarized state is prevented from being incident on the optical switching element. Thus, the occurrence of a crosstalk phenomenon due to light that is not from the scanning signal light emitting element (e.g., light from a backlight in a liquid crystal display device) is suppressed, and an image is displayed with a high quality.
- In the fifth display device of the present invention, the scanning signal light emitting element is formed in a dot-like shape, and substantially only light that is emitted from a scanning signal light emitting element that is associated with an optical switching element is incident on the optical switching element. Therefore, the power supplied to the scanning signal light emitting element is efficiently used as scanning signal light, thereby reducing the power consumption. Moreover, light emitted from unintended scanning signal light emitting elements (light emitting elements other than the scanning signal light emitting element that is associated with the optical switching element) will not be incident on the optical switching element, thereby suppressing the occurrence of a crosstalk phenomenon.
- The present invention provides a display device capable of displaying an image with a high quality while suppressing the occurrence of a signal delay and a crosstalk phenomenon. The present invention can suitably be used with a liquid crystal display device or an organic EL display device.
- FIG. 1 is a cross-sectional view schematically illustrating a liquid
crystal display device 100 ofEmbodiment 1 of the present invention. - FIG. 2A is a plan view schematically illustrating a
substrate 100 c provided in the liquidcrystal display device 100 ofEmbodiment 1 of the present invention. - FIG. 2B is an enlarged view illustrating an
area 2B encircled by a broken line in FIG. 2A. - FIG. 2C is a cross-sectional view taken along line2C-2C′ in FIG. 2B.
- FIG. 2D is a cross-sectional view taken along
line 2D-2D′ in FIG. 2B. - FIG. 3A is a diagram illustrating an angular distribution of light emitted from a scanning signal
light emitting element 42 in a case where an air layer exists between the scanning signallight emitting element 42 and anoptical switching element 14. - FIG. 3B is a diagram illustrating an angular distribution of light emitted from the scanning signal
light emitting element 42 in a case where an air layer does not exist between the scanning signallight emitting element 42 and theoptical switching element 14. - FIG. 4 is a cross-sectional view schematically illustrating a liquid
crystal display device 600 in which the distance between theoptical switching element 14 and the scanning signallight emitting element 42 is equal to or greater than the pixel pitch. - FIG. 5 is a cross-sectional view schematically illustrating a liquid
crystal display device 200 of Embodiment 2 of the present invention. - FIG. 6 is a cross-sectional view schematically illustrating a liquid
crystal display device 300 of Embodiment 3 of the present invention. - FIG. 7 is a cross-sectional view schematically illustrating a focus lens used as a focusing
element 45 provided in the liquidcrystal display device 300 of Embodiment 3 of the present invention. - FIG. 8 is a cross-sectional view schematically illustrating a liquid
crystal display device 400 of Embodiment 4 of the present invention. - FIG. 9 is a cross-sectional view schematically illustrating an organic
EL display device 500 of an alternative embodiment of the present invention. - FIG. 10 is a cross-sectional view schematically illustrating an organic
EL display device 500′ of an alternative embodiment of the present invention. - FIG. 11A is a plan view schematically illustrating a
light guide element 42″ for emitting dotted light. - FIG. 11B is an enlarged view illustrating an
area 11B encircled by a broken line in FIG. 11A. - FIG. 11C is a cross-sectional view taken along line11C-11C′ in FIG. 11B.
- The present inventor has conducted an in-depth study on the use of an optical switching element as a switching element to be provided in each pixel, and has found that it is preferred that the optical switching element and the scanning signal light emitting element are sufficiently separated from each other. This will be discussed in greater detail below.
- For example, in a case where organic EL elements are used as the scanning signal light emitting elements, scanning signal lines are required for applying scanning signals to the organic EL elements. In such a case, the scanning signal lines and data signal lines for applying data signals to optical switching elements are provided so as to cross each other, thereby forming a capacitor at each intersection therebetween. Therefore, a signal delay may occur due to such a capacitor, thereby adversely influencing the display quality. In order to prevent the adverse influence of a signal delay, a large distance can be provided between the data signal lines and the scanning signal light emitting elements, i.e., the optical switching elements and the scanning signal light emitting elements can be sufficiently separated from each other, so that the capacitance value of a capacitor formed at each intersection therebetween is so small that the adverse influence thereof on the display quality is negligible.
- Moreover, although the capacitor as described above is not formed in a case where the scanning signal light emitting element is, for example, a combination of a cold-cathode tube and an optical waveguide, it is still preferred that the optical switching elements and the scanning signal light emitting elements are sufficiently separated from each other. Specifically, it is preferred that the scanning signal light emitting elements are provided on a substrate that is different from a substrate on which the optical switching elements are formed, or on the same substrate on which the optical switching elements are formed, but on a side of the substrate on which the optical switching elements are not formed. By providing the scanning signal light emitting elements in such a manner, the yield of the display device improves.
- As described above, it is preferred that the optical switching elements and the scanning signal light emitting elements are sufficiently separated from each other in view of the signal delay suppression and/or the production yield. However, since light emitted from a scanning signal light emitting element generally has a certain angle of divergence (a certain angular distribution), a crosstalk phenomenon is more likely to occur as the distance between the optical switching element and the scanning signal light emitting element is increased.
- Japanese Laid-Open Patent Publication No. 10-288965 discloses suppressing a crosstalk phenomenon by providing a pin hole mask between the optical switching elements and the scanning signal light emitting elements, but fails to disclose findings as those above on the distance between the optical switching element and the scanning signal light emitting element. In fact, even if a pin hole mask is used, a crosstalk phenomenon is not suppressed sufficiently in some cases. This is because the essential effect of the use of a pin hole mask is merely a reduction in the size of the scanning signal light emitting element.
- Embodiments of the present invention will now be described with reference to the drawings. Note that the present invention is not limited to the embodiments below.
- FIG. 1 is a cross-sectional view schematically illustrating a liquid
crystal display device 100, which is a display device ofEmbodiment 1 of the present invention. The liquidcrystal display device 100 is an active matrix type liquid crystal display device in which a plurality of pixels are arranged in a matrix pattern. - The liquid
crystal display device 100 includes a plurality ofpixel electrodes 12 defining a plurality of pixels,optical switching elements 14 electrically connected to thepixel electrodes 12, respectively, and scanning signallight emitting elements 42 for emitting dotted light, as scanning signals, to theoptical switching elements 14. The distance between theoptical switching element 14 and the scanning signallight emitting element 42 is less than the pixel pitch, at which the plurality of pixels are arranged. - The structure of the liquid
crystal display device 100 will be described in greater detail with reference to FIG. 1. - The liquid
crystal display device 100 includes anactive matrix substrate 100a and acolor filter substrate 100 b opposing each other, with aliquid crystal layer 30 being provided therebetween. - The
active matrix substrate 100 a includes a transparent substrate (e.g., a glass substrate or a polymer film) 10, thepixel electrodes 12, theoptical switching elements 14 electrically connected to thepixel electrodes 12, respectively, and data signal lines (source lines) 16 for supplying data signals to theoptical switching elements 14. Thepixel electrodes 12 are formed in a matrix pattern on thetransparent substrate 10 by using a transparent conductive material (e.g., ITO). Theoptical switching elements 14 are made of, for example, CdS, Se, ZnO or amorphous Si. When theoptical switching element 14 is irradiated with light, electrons and carriers are generated by the optical energy of the light, and thus the resistance value of theoptical switching element 14 decreases, whereby theoptical switching element 14 is turned into a conductive state, i.e., turned ON. - The
color filter substrate 100 b is provided on the viewer side of theactive matrix substrate 100 a, and includes a transparent substrate (e.g., a glass substrate or a polymer film) 20, acolor filter layer 22, alight blocking layer 24 and acounter electrode 26. Thecolor filter layer 22, thelight blocking layer 24 and thecounter electrode 26 are provided on one side of thetransparent substrate 20 that is closer to theliquid crystal layer 30. Thecounter electrode 26 is formed by using a transparent conductive material (e.g., ITO) and, in the present embodiment, is a single common electrode opposing a plurality of pixel electrodes. - Depending on the
liquid crystal layer 30 to be used, alignment layers (e.g., horizontal alignment layers) 18 and 28 are provided on one side of theactive matrix substrate 100 a and thecolor filter substrate 100 b, respectively, that is closer to theliquid crystal layer 30. Moreover,polarizing plates active matrix substrate 100 a and on the viewer side of thecolor filter substrate 100 b, respectively. - The liquid
crystal display device 100 further includes anadditional substrate 100 c provided on the back side of theactive matrix substrate 100 a, and abacklight 50 provided on the back side of thesubstrate 100 c. - The
substrate 100 c includes a transparent substrate (e.g., a glass substrate) 40, alight blocking layer 41 provided on the viewer side of thetransparent substrate 40, and the scanning signallight emitting element 42 provided on thelight blocking layer 41. Thelight blocking layer 41 may be, for example, a metal layer (about 100 nm thick) such as an aluminum layer or a silver layer, a black resin layer (about 1 μm thick), or a layered structure of a chromium layer (about 100 nm thick) and a chromium oxide layer (about 100 nm thick). - The scanning signal
light emitting element 42 emits dotted light, as a scanning signal, to theoptical switching element 14. In the present embodiment, an organic EL (electroluminescence) element formed in a dot-like shape is used as the scanning signallight emitting element 42. The scanning signallight emitting element 42 of the liquidcrystal display device 100 of the present embodiment will now be described in greater detail with reference to FIG. 2A to FIG. 2D. FIG. 2A is a plan view schematically illustrating thesubstrate 100 c of the liquidcrystal display device 100, FIG. 2B is an enlarged view illustrating anarea 2B encircled by a broken line in FIG. 2A, FIG. 2C is a cross-sectional view taken along line 2C-2C′ in FIG. 2B, and FIG. 2D is a cross-sectional view taken alongline 2D-2D′ in FIG. 2B. - The scanning signal
light emitting element 42 includes a reflection electrode (e.g., an aluminum layer having a thickness of about 100 nm) 61 formed in a stripe shape on thetransparent substrate 40, a light emitting layer (an organic electroluminescence material layer) 62 formed on thereflection electrode 61, an insulatinglayer 63 formed on thereflection electrode 61, and a transparent electrode (e.g., an ITO layer having a thickness of about 150 nm) 64 formed on thelight emitting layer 62 and the insulatinglayer 63. - The
light emitting layer 62 provided between thereflection electrode 61 and thetransparent electrode 64 is formed in a dot-like shape at a position corresponding to theoptical switching element 14, and the insulatinglayer 63 is formed so as to surround the dot-shapedlight emitting layer 62. The dot-shapedlight emitting layer 62, and thereflection electrode 61 and thetransparent electrode 64 interposing thelight emitting layer 62 therebetween, together function as a scanning signallight emitting element 42. Oneoptical switching element 14 is provided for each pixel, and one scanning signallight emitting element 42 is provided for each optical switchingelement 14. The stripe-shapedreflection electrode 61 is provided for each row of pixels, for example, and a plurality of scanning signallight emitting elements 42 belonging to one row of pixels together function as a scanning signal line (gate line) 42′. - In the liquid
crystal display device 100 having such a structure, first, dotted light, as scanning signals, is emitted from the scanning signallight emitting elements 42 to theoptical switching elements 14, whereby theoptical switching elements 14 are turned ON in a line sequential manner. In synchronism with this, data signals (display signals) are supplied from the data signallines 16 to theoptical switching elements 14, whereby a voltage according to a data signal is applied to thepixel electrode 12 of each pixel via theoptical switching element 14. - A predetermined voltage is applied to the
counter electrode 26 opposing a plurality ofpixel electrodes 12, and the orientation of liquid crystal molecules of theliquid crystal layer 30 changes according to the voltage (potential difference) between eachpixel electrode 12 and thecounter electrode 26 so as to modulate light from thebacklight 50 according to the change in the orientation, thereby displaying an image. - In the liquid
crystal display device 100 ofEmbodiment 1 of the present invention, the distance between the scanning signallight emitting element 42 and theoptical switching element 14 is less than the pixel pitch, at which the plurality of pixels are arranged. In other words, the distance between the scanning signallight emitting element 42 and theoptical switching element 14 is less than the arrangement pitch of theoptical switching elements 14. This is because the arrangement pitch of theoptical switching elements 14, which are provided one in each pixel, is typically substantially equal to the pixel pitch. - With such a structure, light emitted from a scanning signal
light emitting element 42 that is associated with oneoptical switching element 14 is prevented from being incident on other optical switching elements (e.g., an optical switching element adjacent to the intended optical switching element) 14. The reason therefor will now be described with reference to FIG. 3A and FIG. 3B. Note that the following description is for a case where the scanning signallight emitting element 42 emits light in an isotropic manner. - First, a case where an air layer exists between the scanning signal
light emitting element 42 and theoptical switching element 14 will be described. In such a case, light emitted from the scanning signallight emitting element 42 is distributed across an angular range of about 45° with the center line thereof corresponding to the straight line extending between the scanning signallight emitting element 42 and theoptical switching element 14 associated therewith, as illustrated in FIG. 3A. Therefore, if theoptical switching elements 14 are arranged so that adjacentoptical switching elements 14 are absent in an area within such an angular range, light emitted from the scanning signallight emitting element 42 will not be incident on the adjacentoptical switching elements 14. Thus, if the distance between the scanning signallight emitting element 42 and theoptical switching element 14 is less than the arrangement pitch of theoptical switching elements 14, light is prevented from being incident on adjacentoptical switching elements 14. - Next, a case where an air layer does not exist between the scanning signal
light emitting element 42 and theoptical switching element 14 will be described. In a case where an air layer does not exist, light emitted from a scanning signallight emitting element 42, which emits light in an isotropic manner, may be incident on unintendedoptical switching elements 14 adjacent to theoptical switching element 14 that is associated with the scanning signallight emitting element 42, as illustrated in FIG. 3B. However, if the intensity of light that is incident on such an adjacent, unintendedoptical switching element 14 is less than one half of the intensity of light that is incident on the intended optical switchingelement 14, it can be considered that scanning signal light is substantially not incident on the adjacentoptical switching element 14. This is because even if light of such an intensity is incident on an adjacentoptical switching element 14, the adjacentoptical switching element 14 will not be turned ON. - The light intensity (light intensity per unit area) at a particular point in the plane along which the
optical switching elements 14 are arranged is in proportion to (cos θ)2, where θ is the angle of a straight line extending between the particular point and the scanning signallight emitting element 42 with respect to another straight line extending between the scanning signallight emitting element 42 and theoptical switching element 14 that is associated with the scanning signallight emitting element 42. Accordingly, the intensity of light emitted from a scanning signallight emitting element 42 that is incident on a point where θ>45° is less than one half of the intensity of light that is incident on theoptical switching element 14 associated with the scanning signallight emitting element 42. Thus, if theoptical switching elements 14 are arranged so that adjacentoptical switching elements 14 are each located at a point where θ>45°, it can be considered that scanning signal light is substantially not incident on the adjacentoptical switching element 14. Therefore, even in a case where an air layer does not exist, if the distance between the scanning signallight emitting element 42 and theoptical switching element 14 is less than the arrangement pitch of theoptical switching elements 14, light is prevented from being incident on an adjacentoptical switching element 14. - In the liquid
crystal display device 100 ofEmbodiment 1 of the present invention, the distance between theoptical switching element 14 and the scanning signallight emitting element 42 is less than the pixel pitch at which the plurality of pixels are arranged, whereby light emitted from the scanning signallight emitting element 42 is prevented from being incident on theoptical switching element 14 of an adjacent pixel. Thus, the occurrence of a crosstalk phenomenon is suppressed, and an image is displayed with a high quality. - Note that each pixel, in which the
optical switching element 14 is provided, typically has a generally rectangular shape, whereby the repeating pitch of the pixels in the longitudinal direction of the pixel may be different from that in the width direction of the pixel. Therefore, the arrangement pitch of theoptical switching elements 14 in the longitudinal direction of the pixel may also be different from that in the width direction of the pixel. In order to more reliably suppress the occurrence of a crosstalk phenomenon, it is preferred that the distance between the scanning signallight emitting element 42 and theoptical switching element 14 is less than the pixel pitch in the width direction of the pixel. It is possible to provide a large distance between the scanning signallight emitting element 42 and theoptical switching element 14 if the width direction of the pixel is parallel to the scanning lines. - Moreover, the liquid
crystal display device 100 ofEmbodiment 1 of the present invention includes thelight blocking layer 41, which is provided on one side of the scanning signallight emitting element 42 that is closer to- thebacklight 50. Thus, light from thebacklight 50 is prevented from being incident on theoptical switching element 14, thereby preventing the occurrence of a crosstalk phenomenon due to light from thebacklight 50. - Furthermore, since each scanning signal
light emitting element 42 is formed in a dot-like shape in the liquidcrystal display device 100, the power supplied to the scanning signallight emitting element 42 is efficiently used as scanning signal light, thereby reducing the power consumption. - On the other hand, in a liquid
crystal display device 600 in which the distance between theoptical switching element 14 and the scanning signallight emitting element 42 is equal to or greater than the pixel pitch, as illustrated in FIG. 4, light emitted from the scanning signallight emitting element 42 may be incident on theoptical switching element 14 of an adjacent pixel to cause a crosstalk phenomenon. Note that the liquidcrystal display device 600 illustrated in FIG. 4 has substantially the same structure as that of the liquidcrystal display device 100 ofEmbodiment 1, except that the distance between theoptical switching element 14 and the scanning signallight emitting element 42 is equal to or greater than the pixel pitch. - Moreover, even when a pin hole mask is provided on the scanning signal light emitting elements, light is incident on adjacent optical switching elements to cause a crosstalk phenomenon if the distance between the optical switching element and the scanning signal light emitting element is equal to or greater than the pixel pitch, because the essential effect of the use of a pin hole mask on the scanning signal light emitting elements is merely a reduction in the size of the scanning signal light emitting element.
- FIG. 5 is a cross-sectional view schematically illustrating a liquid
crystal display device 200, which is a display device of Embodiment 2 of the present invention. In FIG. 5, elements having substantially the same functions as those of the liquidcrystal display device 100 ofEmbodiment 1 are denoted by the same reference numerals and will not be further described below. Note that in the liquidcrystal display device 200, the distance between theoptical switching element 14 and the scanning signallight emitting element 42 may be either less than the pixel pitch (as in the liquidcrystal display device 100 of Embodiment 1) or equal to or greater than the pixel pitch. - The liquid
crystal display device 200 includes alouver 44 provided between theoptical switching element 14 and the scanning signallight emitting element 42. Thelouver 44 blocks light that is emitted obliquely from the scanning signallight emitting element 42. - The
louver 44 is an optical element including a plurality of light blocking walls that are formed generally parallel to the straight line extending between the scanning signallight emitting element 42 and theoptical switching element 14 associated therewith. In the present embodiment, thelouver 44 is provided immediately on the scanning signallight emitting element 42. - Light that is emitted obliquely from the scanning signal
light emitting element 42, i.e., light that is emitted in an inclined direction with respect to the straight line extending between the scanning signallight emitting element 42 and theoptical switching element 14 associated therewith, is absorbed and blocked by the light blocking walls of thelouver 44. Note that light that is emitted from the scanning signallight emitting element 42 and transmitted through thelouver 44 may actually have a slight angular distribution (angle of divergence) according to the arrangement pitch, the height, etc., of the light blocking walls. - As described above, the liquid
crystal display device 200 of Embodiment 2 of the present invention includes thelouver 44 provided between theoptical switching element 14 and the scanning signallight emitting element 42, whereby light that is emitted obliquely from the scanning signallight emitting element 42 is blocked by thelouver 44. Therefore, light emitted from a scanning signallight emitting element 42 is prevented from being incident on an unintendedoptical switching element 14 adjacent to anoptical switching element 14 that is associated with the scanning signallight emitting element 42. Thus, the occurrence of a crosstalk phenomenon is suppressed, and an image is displayed with a high quality. - On the other hand, in the liquid
crystal display device 600 in which the distance between theoptical switching element 14 and the scanning signallight emitting element 42 is equal to or greater than the pixel pitch, and in which no louver is provided, as illustrated in FIG. 4, light emitted from the scanning signallight emitting element 42 may be incident on theoptical switching element 14 of an adjacent pixel to cause a crosstalk phenomenon. - FIG. 6 is a cross-sectional view schematically illustrating a liquid
crystal display device 300, which is a display device of Embodiment 3 of the present invention. While the liquidcrystal display device 200 of Embodiment 2 includes thelouver 44 for blocking light that is emitted obliquely from the scanning signallight emitting element 42, the liquidcrystal display device 300 of Embodiment 3 includes a focusingelement 45 for focusing light emitted from the scanning signallight emitting element 42 on a predetermined area. In FIG. 6, elements having substantially the same functions as those of the liquidcrystal display device 200 of Embodiment 2 are denoted by the same reference numerals and will not be further described below. - The liquid
crystal display device 300 of Embodiment 3 includes the focusingelement 45 provided between theoptical switching element 14 and the scanning signallight emitting element 42. The focusingelement 45 focuses light emitted from the scanning signallight emitting element 42 on a predetermined area. In the present embodiment, the focusingelement 45 is provided immediately on the scanning signallight emitting element 42 of thesubstrate 100 c. - The focusing
element 45 may be, for example, a focusinglens 45 including atransparent resin layer 45 a, tapered reflection surfaces 45 b provided in thetransparent resin layer 45 a so as to surround the scanning signallight emitting element 42, andlens sections 45 c each provided over the scanning signallight emitting element 42 surrounded by the tapered reflection surfaces 45 b, as illustrated in FIG. 7. - In a case where the focusing
lens 45 as illustrated in FIG. 7 is provided, light that is emitted with a certain angular distribution (i.e., divergently emitted light) from the scanning signallight emitting element 42 is collimated by the taperedreflection surface 45 b, and focused on a predetermined area by thelens section 45 c. For example, light emitted from the scanning signallight emitting element 42 is focused on an area that coincides with theoptical switching element 14 that is associated with the scanning signallight emitting element 42. - As described above, the liquid
crystal display device 300 of Embodiment 3 of the present invention includes the focusingelement 45 provided between theoptical switching element 14 and the scanning signallight emitting element 42 for focusing light emitted from the scanning signallight emitting element 42 on a predetermined area. Therefore, light emitted from a scanning signal light emitting element is focused on a predetermined area, whereby the light emitted from the scanning signal light emitting element is prevented from being incident on an optical switching element in an adjacent pixel. Thus, the occurrence of a crosstalk phenomenon is suppressed, and an image is displayed with a high quality. - On the other hand, in the liquid
crystal display device 600 in which the distance between theoptical switching element 14 and the scanning signallight emitting element 42 is equal to or greater than the pixel pitch, and in which no focusing element is provided, as illustrated in FIG. 4, light emitted from the scanning signallight emitting element 42 may be incident on theoptical switching element 14 of an adjacent pixel to cause a crosstalk phenomenon. - Note that while FIG. 6 illustrates an arrangement where the
polarizing plate 19, one of a pair of polarizing plates, is provided on the back side of theactive matrix substrate 100 a, thepolarizing plate 19 may alternatively be provided on the back side of thesubstrate 100 c. In a case where the focusingelement 45 as described above is provided, substantially no decrease in the display quality due to light emitted from the scanning signallight emitting element 42 is observed even if thepolarizing plate 19 is provided on the back side of thesubstrate 100 c. - Moreover, the focusing
element 45 is not limited to the focusinglens 45 including the taperedreflection surface 45 b and thelens section 45 c combined together, as illustrated in FIG. 7, but may alternatively be a focusing lens including a pin hole mask and a lens section combined together. - FIG. 8 is a cross-sectional view schematically illustrating a liquid
crystal display device 400 of Embodiment 4 of the present invention. In FIG. 8, elements having substantially the same functions as those of the liquidcrystal display devices - The liquid
crystal display device 400 of Embodiment 4 has a structure such that light emitted from the scanning signallight emitting element 42 is modulated into a predetermined polarized state, and substantially only light that is in the predetermined polarized state is incident on theoptical switching element 14. - More specifically, the liquid
crystal display device 400 includes a firstpolarizing element 72 provided between theoptical switching element 14 and the scanning signallight emitting element 42, and a secondpolarizing element 74 provided between the firstpolarizing element 72 and theoptical switching element 14. Moreover, apolarizing plate 19′, i.e., one of the pair ofpolarizing plates crystal display device 400 that is on the side closer to thebacklight 50, is provided on the back side of thesubstrate 100 c. - The first
polarizing element 72 modulates light emitted from the scanning signallight emitting element 42 into a predetermined polarized state. Moreover, the secondpolarizing element 74 is arranged so that light that is in the predetermined polarized state is selectively transmitted therethrough. - In the present embodiment, each of the first
polarizing element 72 and the secondpolarizing element 74 is an absorption type polarizing element that transmits linearly-polarized light of a particular polarization direction while absorbing linearly-polarized light whose polarization direction is perpendicular to the particular polarization direction. The firstpolarizing element 72 and the secondpolarizing element 74 are arranged so that the transmission axis directions thereof are parallel to each other. Moreover, the firstpolarizing element 72 and the secondpolarizing element 74 are arranged so that the transmission axis directions thereof are perpendicular to the transmission axis direction of thepolarizing plate 19′ on the backlight side. - Light emitted from the scanning signal
light emitting element 42 is polarized by the firstpolarizing element 72 into linearly-polarized light having a polarization direction that is parallel to the transmission axis direction of the firstpolarizing element 72. Since the transmission axis direction of the firstpolarizing element 72 and the transmission axis direction of the secondpolarizing element 74 are parallel to each other, the light, which has been polarized by the firstpolarizing element 72 into linearly-polarized light, is transmitted through the secondpolarizing element 74 to be incident on theoptical switching element 14. - In contrast, light emitted from the
backlight 50 is polarized by thepolarizing plate 19′ into linearly-polarized light having a polarization direction that is parallel to the transmission axis direction of thepolarizing plate 19′. Since the transmission axis direction of thepolarizing plate 19′ and the transmission axis direction of the secondpolarizing element 74 are perpendicular to each other, the light, which has been emitted from thebacklight 50 and transmitted through thepolarizing plate 19′, is absorbed by the secondpolarizing element 74 and will not be incident on theoptical switching element 14. - As described above, the liquid
crystal display device 400 of Embodiment 4 has a structure such that light emitted from the scanning signallight emitting element 42 is modulated into a predetermined polarized state, and substantially only light that is in the predetermined polarized state is incident on theoptical switching element 14, whereby light from thebacklight 50 is prevented from being incident on theoptical switching element 14. Thus, the occurrence of a crosstalk phenomenon due to light from thebacklight 50 is suppressed, and an image is displayed with a high quality. - As described above, in the liquid
crystal display device 400 of the present embodiment, the occurrence of a crosstalk phenomenon is suppressed by using the polarization selectivity of a polarizing element, thereby providing a higher effect of suppressing the occurrence of a crosstalk phenomenon due to light from thebacklight 50, as compared with a structure where thelight blocking layer 41 is used, as in the liquidcrystal display devices Embodiments 1, 2 and 3. - Note that the first polarizing element and the second polarizing element are not limited to a polarizing element as illustrated in the present embodiment, but may alternatively be an absorption type polarizing element that contains a dye (e.g., iodine), or a reflection type polarizing element. Reflection type polarizing elements that can be used in the present invention include, for example, DBEF (manufactured by SUMITOMO 3M Limited), which transmits polarized light of a particular polarization direction while reflecting polarized light whose polarization direction is perpendicular to the particular polarization direction, or a polarizing element made of a cholesteric liquid crystal material, which only transmits either left or right circularly-polarized light while reflecting the other circularly-polarized light.
- Moreover, in the liquid
crystal display device 400 of Embodiment 4, the distance between theoptical switching element 14 and the scanning signallight emitting element 42 may be set to be less than the pixel pitch as in the liquidcrystal display device 100 ofEmbodiment 1; a louver may be provided between theoptical switching element 14 and the scanning signallight emitting element 42 as in the liquidcrystal display device 200 of Embodiment 2; or a focusing element may be provided between theoptical switching element 14 and the scanning signallight emitting element 42 as in the liquidcrystal display device 300 of Embodiment 3. With such a structure, it is possible not only to suppress the occurrence of a crosstalk phenomenon due to light from thebacklight 50, but also to suppress the occurrence of a crosstalk phenomenon due to light that is emitted from a scanning signallight emitting element 42 and is incident on an unintendedoptical switching element 14 adjacent to anoptical switching element 14 that is associated with the scanning signallight emitting element 42, whereby an image is displayed with an even higher quality. - While a liquid crystal display device including the
liquid crystal layer 30 as a display medium layer has been described above inEmbodiments 1, 2, 3 and 4, the present invention is not limited thereto. For example, the present invention can suitably be used with an organicEL display device 500 including an organic EL material layer (organic EL element) as illustrated in FIG. 9. FIG. 9 is a cross-sectional view schematically illustrating the organicEL display device 500, which is a display device of an alternative embodiment of the present invention. - The organic
EL display device 500 includes afirst substrate 500 a and a second substrate 500 b provided on the back side of thefirst substrate 500 a. - The
first substrate 500 a includes a transparent substrate (e.g., a glass substrate or a polymer film) 80, a plurality ofpixel electrodes 82,optical switching elements 84 electrically connected to thepixel electrodes 82, respectively, data signallines 86 for supplying data signals to theoptical switching elements 84, an organicEL material layer 83 provided on eachpixel electrode 82, and a counter electrode (e.g., an aluminum layer) 85 opposing thepixel electrode 82 via the organicEL material layer 83. Thepixel electrodes 82 are formed in a matrix pattern on thetransparent substrate 80 by using a transparent conductive material (e.g., ITO). - The
first substrate 500 a further includes alight blocking layer 87 provided on the viewer side of theoptical switching element 84, a transparent insulating layer (e.g., an SiO2 layer having a thickness of about 150 nm) 88 provided on theoptical switching element 84 and the data signalline 86, and a transparent conductive layer (e.g., an ITO layer) 89 provided so as to cover the transparent insulatinglayer 88 and thecounter electrode 85. Thecounter electrodes 85 opposing therespective pixel electrodes 82 are electrically connected to one another by the transparentconductive layer 89, and together function as a single counter electrode opposing thepixel electrodes 82. - The second substrate500 b includes a transparent substrate (e.g., a glass substrate or a polymer film) 90, and scanning signal
light emitting elements 92 provided on the transparent substrate 90. The scanning signallight emitting element 92 may be, for example, an organic EL element as illustrated in FIG. 2B to FIG. 2D. - Embodiments 1 to 3 of the present invention may also be used with the organic
EL display device 500 illustrated in FIG. 9. For example, the distance between theoptical switching element 84 and the scanning signallight emitting element 92 may be set to be less than the pixel pitch as in the liquidcrystal display device 100 ofEmbodiment 1; a louver may be provided between theoptical switching element 84 and the scanning signallight emitting element 92 as in the liquidcrystal display device 200 of Embodiment 2; or a focusing element may be provided between theoptical switching element 84 and the scanning signallight emitting element 92 as in the liquidcrystal display device 300 of Embodiment 3. In such a case, light emitted from a scanning signallight emitting element 92 is prevented from being incident on an unintendedoptical switching element 84 adjacent to anoptical switching element 84 that is associated with the scanning signallight emitting element 92, thereby suppressing the occurrence of a crosstalk phenomenon. - Moreover, in the organic
EL display device 500 of the present embodiment, thelight blocking layer 87 is provided on the viewer side of theoptical switching element 84, whereby light emitted from the scanning signallight emitting element 92 to theoptical switching element 84 is prevented from being transmitted to the viewer side. Thus, a reduction in the contrast ratio is suppressed. - Note that the organic EL display device with which the present invention can suitably be used is not limited to the organic
EL display device 500 as illustrated in FIG. 9, but may alternatively be, for example, an organicEL display device 500′ as illustrated in FIG. 10. - The organic
EL display device 500′ illustrated in FIG. 10 includes afirst substrate 500 a′, and a second substrate 500 b′ provided on the back side of thefirst substrate 500 a′. - The
first substrate 500 a′ includes a transparent substrate (e.g., a glass substrate or a polymer film) 80′, asingle counter electrode 85′ formed on thetransparent substrate 80′ by using a transparent conductive material (e.g., ITO), an organicEL material layer 83′ provided on thecounter electrode 85′, a transparent insulating layer (e.g., an SiO2 layer having a thickness of about 150 nm) 88′ provided on thecounter electrode 85′, a plurality of pixel electrodes (e.g., an aluminum layer) 82′ formed in a matrix pattern and opposing thecounter electrode 85′ via the organicEL material layer 83′,optical switching elements 84′ electrically connected to thepixel electrodes 82′, respectively, and data signallines 86′ for supplying data signals to theoptical switching elements 84′. Thefirst substrate 500 a′ further includes alight blocking layer 87′ provided on the viewer side of theoptical switching element 84′. - The second substrate500 b′ includes a transparent substrate (e.g., a glass substrate or a polymer film) 90′, and scanning signal
light emitting elements 92′ provided on the transparent substrate 90′. The scanning signallight emitting element 92′ may be, for example, an organic EL element as illustrated in FIG. 2B to FIG. 2D. - Embodiments 1 to 3 of the present invention may also be used with the organic
EL display device 500′ having such a structure so as to suppress the occurrence of a crosstalk phenomenon. - As described above, the present invention can suitably be used with liquid crystal display devices and organic EL display devices.
- The thickness of an active matrix substrate of a liquid crystal display device is currently 500 μm to 700 μm, and the pixel pitch of a liquid crystal display device is currently 200 μm to 800 μm. Therefore, it is often the case with a liquid crystal display device that the distance between the optical switching element and the scanning signal light emitting element is equal to or greater than the pixel pitch. The occurrence of a crosstalk phenomenon can be suppressed by setting the distance between the optical switching element and the scanning signal light emitting element to be less than the pixel pitch, by providing a louver, or by providing a focusing element, as in
Embodiments 1 to 3. Moreover, in some liquid crystal display devices, a backlight is provided on the back side of the device, whereby light from the backlight may be incident on the optical switching element. The occurrence of a crosstalk phenomenon due to light from a backlight can be suppressed by providing a light emitting layer on the backlight side of the scanning signal light emitting element as inEmbodiments 1 to 3, or by utilizing the polarization selectivity of a polarizing element as in Embodiment 4. - On the other hand, in an organic EL display device, it may not be necessary to provide a substrate between scanning signal light emitting elements and optical switching elements. Therefore, it is easy to set the distance between the optical switching element and the scanning signal light emitting element to be less than 200 μm to 300 μm, i.e., a distance with which the occurrence of a crosstalk phenomenon is generally prevented and to be greater than about 1 μm at which a signal delay becomes problematic.
- Note that while the description above has been directed to a case where dot-shaped scanning signal light emitting elements are provided, as illustrated in FIG. 2B to FIG. 2D, the present invention is not limited thereto, and any scanning signal light emitting element that emits dotted light may be used.
- For example, a scanning signal light emitting element that emits dotted light may be a combination of a light emitting element that emits light in a linear or planar pattern with a pin hole mask, or a combination of a
light guide element 42″ as illustrated in FIG. 11A, FIG. 11B and FIG. 11C with a light source. - FIG. 11A is a plan view schematically illustrating the
light guide element 42″, FIG. 11B is an enlarged view illustrating anarea 11B encircled by a broken line in FIG. 11A, and FIG. 11C is a cross-sectional view taken along line 11C-11C′ in FIG. 11B. - The
light guide elements 42″ are provided in a stripe pattern on thesubstrate 100 c, as illustrated in FIG. 11A, and a light source (e.g., a cold-cathode tube; not shown) is provided at an end of eachlight guide element 42″. As illustrated in FIG. 11B and FIG. 11C, thelight guide element 42″ includesdepressions 42 a″, each of which is formed on the back side surface of thelight guide element 42″ in a dot-like shape so as to correspond to the optical switching element of each pixel. The shape of thedepression 42 a″ is, for example, a conical shape as illustrated in FIG. 11B and FIG. 11C. - Light, which has been emitted from the light source and has entered the
light guide element 42″, travels through the inside of thelight guide element 42″ while being totally reflected repeatedly by the side surfaces of thelight guide element 42″, as illustrated in FIG. 11C. Some of the light traveling through the inside of thelight guide element 42″ is reflected by thedepression 42 a″. Such light is incident on the viewer-side side surface at an angle such that the light is not totally reflected, and thus comes out of thelight guide element 42″. In this way, thelight guide element 42″ functions as a scanning signal light emitting element that emits dotted light, as scanning signals, to the optical switching elements. - Moreover, while the description above has been directed to a case where scanning signal light emitting elements are provided on a substrate that is different from a substrate on which optical switching elements are provided, the present invention is not limited to this arrangement of the scanning signal light emitting elements. For example, the scanning signal light emitting elements may alternatively be provided on the same substrate on which the optical switching elements are provided, but on a side of the substrate on which the optical switching elements are not provided.
- While the present invention has been described in preferred embodiments, it will be apparent to those skilled in the art that the disclosed invention may be modified in numerous ways and may assume many embodiments other than those specifically set out and described above. Accordingly, it is intended by the appended claims to cover all modifications of the invention that fall within the true spirit and scope of the invention.
Claims (42)
1. A display device, comprising:
a plurality of pixel electrodes defining a plurality of pixels that are arranged in a matrix pattern;
optical switching elements electrically connected to the plurality of pixel electrodes, respectively; and
scanning signal light emitting elements for emitting dotted light, as scanning signals, to the optical switching elements,
wherein a distance between the optical switching element and the scanning signal light emitting element is less than a pixel pitch at which the plurality of pixels are arranged.
2. The display device of claim 1 , further comprising:
a backlight provided on a side away from the optical switching element with respect to the scanning signal light emitting element; and
a light blocking layer provided on a side of the scanning signal light emitting element that is closer to the backlight.
3. The display device of claim 1 , wherein light emitted from the scanning signal light emitting element is modulated into a predetermined polarized state, and substantially only light that is in the predetermined polarized state is incident on the optical switching element.
4. The display device of claim 3 , further comprising:
a first polarizing element provided between the optical switching element and the scanning signal light emitting element for modulating light emitted from the scanning signal light emitting element into the predetermined polarized state; and
a second polarizing element provided between the first polarizing element and the optical switching element and arranged so as to selectively transmit light that is in the predetermined polarized state.
5. The display device of claim 1 , further comprising:
at least one counter electrode opposing the plurality of pixel electrodes; and
a liquid crystal layer provided between the plurality of pixel electrodes and the at least one counter electrode.
6. The display device of claim 1 , further comprising:
at least one counter electrode opposing the plurality of pixel electrodes; and
an organic electroluminescence material layer provided between the plurality of pixel electrodes and the at least one counter electrode.
7. The display device of claim 6 , further comprising a light blocking layer provided on a viewer side of the optical switching element.
8. The display device of claim 1 , wherein the scanning signal light emitting element is formed in a dot-like shape.
9. A display device, comprising:
a plurality of pixel electrodes defining a plurality of pixels that are arranged in a matrix pattern;
optical switching elements electrically connected to the plurality of pixel electrodes, respectively;
scanning signal light emitting elements for emitting dotted light, as scanning signals, to the optical switching elements; and
a louver provided between the optical switching element and the scanning signal light emitting element.
10. The display device of claim 9 , further comprising:
a backlight provided on a side away from the optical switching element with respect to the scanning signal light emitting element; and
a light blocking layer provided on a side of the scanning signal light emitting element that is closer to the backlight.
11. The display device of claim 9 , wherein light emitted from the scanning signal light emitting element is modulated into a predetermined polarized state, and substantially only light that is in the predetermined polarized state is incident on the optical switching element.
12. The display device of claim 11 , further comprising:
a first polarizing element provided between the optical switching element and the scanning signal light emitting element for modulating light emitted from the scanning signal light emitting element into the predetermined polarized state; and
a second polarizing element provided between the first polarizing element and the optical switching element and arranged so as to selectively transmit light that is in the predetermined polarized state.
13. The display device of claim 9 , further comprising:
at least one counter electrode opposing the plurality of pixel electrodes; and
a liquid crystal layer provided between the plurality of pixel electrodes and the at least one counter electrode.
14. The display device of claim 9 , further comprising:
at least one counter electrode opposing the plurality of pixel electrodes; and
an organic electroluminescence material layer provided between the plurality of pixel electrodes and the at least one counter electrode.
15. The display device of claim 14 , further comprising a light blocking layer provided on a viewer side of the optical switching element.
16. The display device of claim 9 , wherein the scanning signal light emitting element is formed in a dot-like shape.
17. A display device, comprising:
a plurality of pixel electrodes defining a plurality of pixels that are arranged in a matrix pattern;
optical switching elements electrically connected to the plurality of pixel electrodes, respectively;
scanning signal light emitting elements for emitting dotted light, as scanning signals, to the optical switching elements; and
a focusing element provided between the optical switching element and the scanning signal light emitting element for focusing light emitted from the scanning signal light emitting element on a predetermined area.
18. The display device of claim 17 , wherein the focusing element is a lens.
19. The display device of claim 17 , further comprising:
a backlight provided on a side away from the optical switching element with respect to the scanning signal light emitting element; and
a light blocking layer provided on a side of the scanning signal light emitting element that is closer to the backlight.
20. The display device of claim 17 , wherein light emitted from the scanning signal light emitting element is modulated into a predetermined polarized state, and substantially only light that is in the predetermined polarized state is incident on the optical switching element.
21. The display device of claim 20 , further comprising:
a first polarizing element provided between the optical switching element and the scanning signal light emitting element for modulating light emitted from the scanning signal light emitting element into the predetermined polarized state; and
a second polarizing element provided between the first polarizing element and the optical switching element and arranged so as to selectively transmit light that is in the predetermined polarized state.
22. The display device of claim 17 , further comprising:
at least one counter electrode opposing the plurality of pixel electrodes; and
a liquid crystal layer provided between the plurality of pixel electrodes and the at least one counter electrode.
23. The display device of claim 17 , further comprising:
at least one counter electrode opposing the plurality of pixel electrodes; and
an organic electroluminescence material layer provided between the plurality of pixel electrodes and the at least one counter electrode.
24. The display device of claim 23 , further comprising a light blocking layer provided on a viewer side of the optical switching element.
25. The display device of claim 17 , wherein the scanning signal light emitting element is formed in a dot-like shape.
26. A display device, comprising:
a plurality of pixel electrodes defining a plurality of pixels that are arranged in a matrix pattern;
optical switching elements electrically connected to the plurality of pixel electrodes, respectively; and
scanning signal light emitting elements for emitting dotted light, as scanning signals, to the optical switching elements,
wherein light emitted from the scanning signal light emitting element is modulated into a predetermined polarized state, and substantially only light that is in the predetermined polarized state is incident on the optical switching element.
27. The display device of claim 26 , further comprising:
a first polarizing element provided between the optical switching element and the scanning signal light emitting element for modulating light emitted from the scanning signal light emitting element into the predetermined polarized state; and
a second polarizing element provided between the first polarizing element and the optical switching element and arranged so as to selectively transmit light that is in the predetermined polarized state.
28. The display device of claim 26 , further comprising:
at least one counter electrode opposing the plurality of pixel electrodes; and
a liquid crystal layer provided between the plurality of pixel electrodes and the at least one counter electrode.
29. The display device of claim 26 , further comprising:
at least one counter electrode opposing the plurality of pixel electrodes; and
an organic electroluminescence material layer provided between the plurality of pixel electrodes and the at least one counter electrode.
30. The display device of claim 29 , further comprising a light blocking layer provided on a viewer side of the optical switching element.
31. The display device of claim 26 , wherein the scanning signal light emitting element is formed in a dot-like shape.
32. A display device, comprising:
a plurality of pixel electrodes defining a plurality of pixels that are arranged in a matrix pattern;
optical switching elements electrically connected to the plurality of pixel electrodes, respectively; and
scanning signal light emitting elements, respectively associated with the optical switching elements, for emitting light, as scanning signals, to the optical switching elements,
wherein the scanning signal light emitting element is formed in a dot-like shape, and substantially only light that is emitted from one scanning signal light emitting element that is associated with one optical switching element is incident on the optical switching element.
33. The display device of claim 32 , wherein a distance between one optical switching element and one scanning signal light emitting element that is associated with the optical switching element is less than a pixel pitch at which the plurality of pixels are arranged.
34. The display device of claim 32 , further comprising a louver between at least one optical switching element and at least one scanning signal light emitting element that is associated with the at least one optical switching element.
35. The display device of claim 32 , further comprising a focusing element between at least one optical switching element and at least one scanning signal light emitting element that is associated with the at least one optical switching element for focusing light emitted from the at least one scanning signal light emitting element on a predetermined area.
36. The display device of claim 35 , wherein the focusing element is a lens.
37. The display device of claim 32 , further comprising:
a backlight provided on a side away from the optical switching element with respect to the scanning signal light emitting element; and
a light blocking layer provided on a side of the scanning signal light emitting element that is closer to the backlight.
38. The display device of claim 32 , wherein light emitted from each scanning signal light emitting element is modulated into a predetermined polarized state, and substantially only light that is in the predetermined polarized state is incident on one optical switching element that is associated with the scanning signal light emitting element.
39. The display device of claim 38 , further comprising:
a first polarizing element provided between at least one optical switching element and at least one scanning signal light emitting element that is associated with the at least one optical switching element for modulating light emitted from the at least one scanning signal light emitting element into the predetermined polarized state; and
a second polarizing element provided between the first polarizing element and the at least one optical switching element and arranged so as to selectively transmit light that is in the predetermined polarized state.
40. The display device of claim 32 , further comprising:
at least one counter electrode opposing the plurality of pixel electrodes; and
a liquid crystal layer provided between the plurality of pixel electrodes and the at least one counter electrode.
41. The display device of claim 32 , further comprising:
at least one counter electrode opposing the plurality of pixel electrodes; and
an organic electroluminescence material layer provided between the plurality of pixel electrodes and the at least one counter electrode.
42. The display device of claim 41 , further comprising a light blocking layer provided on a viewer side of the optical switching element.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/813,194 US20040183961A1 (en) | 2001-08-30 | 2004-03-29 | Display device |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2001261067A JP2003066869A (en) | 2001-08-30 | 2001-08-30 | Display device |
JP2001-261067 | 2001-08-30 | ||
US10/230,558 US6750936B2 (en) | 2001-08-30 | 2002-08-29 | Display device |
US10/813,194 US20040183961A1 (en) | 2001-08-30 | 2004-03-29 | Display device |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/230,558 Division US6750936B2 (en) | 2001-08-30 | 2002-08-29 | Display device |
Publications (1)
Publication Number | Publication Date |
---|---|
US20040183961A1 true US20040183961A1 (en) | 2004-09-23 |
Family
ID=19088169
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/230,558 Expired - Lifetime US6750936B2 (en) | 2001-08-30 | 2002-08-29 | Display device |
US10/813,194 Abandoned US20040183961A1 (en) | 2001-08-30 | 2004-03-29 | Display device |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/230,558 Expired - Lifetime US6750936B2 (en) | 2001-08-30 | 2002-08-29 | Display device |
Country Status (2)
Country | Link |
---|---|
US (2) | US6750936B2 (en) |
JP (1) | JP2003066869A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040109106A1 (en) * | 2002-12-09 | 2004-06-10 | Kie-Hsiung Yang | Liquid crystal display device |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR101085444B1 (en) * | 2004-06-25 | 2011-11-21 | 삼성전자주식회사 | Optical member and back light assembly having the light guide plate, and display device having the back light assembly |
KR101427584B1 (en) * | 2008-01-22 | 2014-08-08 | 삼성디스플레이 주식회사 | Display device |
CN202033560U (en) * | 2011-01-14 | 2011-11-09 | 王亚平 | Base plate of an active array liquid crystal display (LCD) panel |
US10708575B2 (en) | 2012-06-25 | 2020-07-07 | Sharp Kabushiki Kaisha | Display system with diffuse and specular reflective modes |
US9679506B2 (en) * | 2012-06-25 | 2017-06-13 | Sharp Kabushiki Kaisha | Multiple function display system |
US10699612B2 (en) | 2014-10-27 | 2020-06-30 | Sharp Kabushiki Kaisha | Display system with specular reflective mode |
US9928371B2 (en) | 2014-11-19 | 2018-03-27 | Papal, Inc. | Systems and methods for protecting information displayed on a user interface of a device |
US9886598B2 (en) | 2014-12-29 | 2018-02-06 | Paypal, Inc. | Automatic adjustment of a display to obscure data |
KR102445774B1 (en) * | 2015-10-01 | 2022-09-21 | 엘지디스플레이 주식회사 | Flexible Display Device |
US9928372B2 (en) * | 2015-10-23 | 2018-03-27 | Paypal, Inc. | Selective screen privacy |
CN110854298A (en) * | 2019-11-26 | 2020-02-28 | 京东方科技集团股份有限公司 | Display panel and display device |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4952031A (en) * | 1987-06-19 | 1990-08-28 | Victor Company Of Japan, Ltd. | Liquid crystal display device |
US5754261A (en) * | 1996-01-15 | 1998-05-19 | Lg Electronics Inc. | Color LCD device having multiple black masks |
US6351010B1 (en) * | 1998-09-22 | 2002-02-26 | Sony Corporation | Electrooptical device, substrate for driving electrooptical device and methods for making the same |
US6870586B2 (en) * | 2001-07-27 | 2005-03-22 | Seiko Epson Corporation | Liquid crystal display device and electronic device |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH01173016A (en) | 1987-12-28 | 1989-07-07 | Toray Ind Inc | Liquid crystal display device using photoconductive body |
US5307189A (en) * | 1991-03-05 | 1994-04-26 | Oki Electric Industry Co., Ltd. | Active-matrix-addressed liquid crystal with conductor collecting lines of force emanating from data electrode |
JPH04367826A (en) | 1991-06-17 | 1992-12-21 | Matsushita Electric Ind Co Ltd | Optical modulating element |
JP3165575B2 (en) * | 1993-12-20 | 2001-05-14 | シャープ株式会社 | Optical information device manufacturing method |
JP3571887B2 (en) * | 1996-10-18 | 2004-09-29 | キヤノン株式会社 | Active matrix substrate and liquid crystal device |
JPH10288965A (en) | 1997-04-14 | 1998-10-27 | Casio Comput Co Ltd | Display device |
JPH11143392A (en) | 1997-11-14 | 1999-05-28 | Sharp Corp | Optical scanning type display device |
US6555422B1 (en) * | 1998-07-07 | 2003-04-29 | Semiconductor Energy Laboratory Co., Ltd. | Thin film transistor and method of manufacturing the same |
TW559683B (en) * | 1998-09-21 | 2003-11-01 | Advanced Display Kk | Liquid display device and manufacturing process therefor |
US6657698B1 (en) * | 1999-08-06 | 2003-12-02 | Rainbow Displays, Inc. | Design features optimized for tiled flat-panel displays |
JP2001210855A (en) * | 2000-01-27 | 2001-08-03 | Sharp Corp | Two-dimensional picture detector |
-
2001
- 2001-08-30 JP JP2001261067A patent/JP2003066869A/en active Pending
-
2002
- 2002-08-29 US US10/230,558 patent/US6750936B2/en not_active Expired - Lifetime
-
2004
- 2004-03-29 US US10/813,194 patent/US20040183961A1/en not_active Abandoned
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4952031A (en) * | 1987-06-19 | 1990-08-28 | Victor Company Of Japan, Ltd. | Liquid crystal display device |
US5754261A (en) * | 1996-01-15 | 1998-05-19 | Lg Electronics Inc. | Color LCD device having multiple black masks |
US6351010B1 (en) * | 1998-09-22 | 2002-02-26 | Sony Corporation | Electrooptical device, substrate for driving electrooptical device and methods for making the same |
US6870586B2 (en) * | 2001-07-27 | 2005-03-22 | Seiko Epson Corporation | Liquid crystal display device and electronic device |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040109106A1 (en) * | 2002-12-09 | 2004-06-10 | Kie-Hsiung Yang | Liquid crystal display device |
US6987547B2 (en) * | 2002-12-09 | 2006-01-17 | Hannstar Display Corp. | Liquid crystal display device |
Also Published As
Publication number | Publication date |
---|---|
JP2003066869A (en) | 2003-03-05 |
US6750936B2 (en) | 2004-06-15 |
US20030043313A1 (en) | 2003-03-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP4180584B2 (en) | Liquid crystal display | |
JP4828557B2 (en) | Liquid crystal display | |
JP4638462B2 (en) | Liquid crystal display device | |
US20100182534A1 (en) | Liquid crystal display device | |
KR20110101893A (en) | Liquid crsytal display | |
US9857642B2 (en) | Display device and liquid crystal display device | |
US9207510B2 (en) | Liquid crystal display device | |
US6750936B2 (en) | Display device | |
JP2007041536A (en) | Display device and liquid crystal display device | |
US9551911B2 (en) | Liquid crystal display device | |
JP4462280B2 (en) | Liquid crystal device and electronic device | |
JP3944649B2 (en) | Liquid crystal display device and electronic device | |
US9341906B2 (en) | Liquid crystal display device | |
US20140016074A1 (en) | Liquid crystal display device | |
KR100843691B1 (en) | Liquid crystal display with two surface display function | |
JP2014115561A (en) | Liquide crystal display device | |
US9134578B2 (en) | Liquid crystal display device | |
JP5779525B2 (en) | Liquid crystal display | |
JP4729923B2 (en) | Liquid crystal device and projection display device | |
JP6508817B2 (en) | Liquid crystal display | |
JP2004206080A (en) | Liquid crystal display and electronic apparatus | |
WO2023142092A1 (en) | Liquid crystal handwriting pad and manufacturing method therefor | |
US9235086B2 (en) | Liquid crystal display device | |
JP2009047772A (en) | Liquid crystal display device | |
JP4946520B2 (en) | Liquid crystal device and electronic device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |