US20080239756A1 - Backlight assembly of liquid crystal display - Google Patents
Backlight assembly of liquid crystal display Download PDFInfo
- Publication number
- US20080239756A1 US20080239756A1 US11/987,674 US98767407A US2008239756A1 US 20080239756 A1 US20080239756 A1 US 20080239756A1 US 98767407 A US98767407 A US 98767407A US 2008239756 A1 US2008239756 A1 US 2008239756A1
- Authority
- US
- United States
- Prior art keywords
- light
- guide plate
- light guide
- prism sheet
- lamp
- 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
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0033—Means for improving the coupling-out of light from the light guide
- G02B6/0035—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
- G02B6/0038—Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0033—Means for improving the coupling-out of light from the light guide
- G02B6/005—Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
- G02B6/0053—Prismatic sheet or layer; Brightness enhancement element, sheet or layer
-
- 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
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/133504—Diffusing, scattering, diffracting elements
-
- 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
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133615—Edge-illuminating devices, i.e. illuminating from the side
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0033—Means for improving the coupling-out of light from the light guide
- G02B6/005—Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
- G02B6/0051—Diffusing sheet or layer
-
- 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
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/13363—Birefringent elements, e.g. for optical compensation
Definitions
- the present invention relates to a non-luminous flat display device, and more particularly, to a backlight assembly of a liquid crystal display with an improved optical sheet.
- Such flat panel displays include a liquid crystal display (LCD), a field emission display, a plasma display panel (PDP), an electro-luminescence (EL) and the like. Research for enhancing the display quality and increasing the screen size of the flat panel displays is being actively performed.
- LCD liquid crystal display
- PDP plasma display panel
- EL electro-luminescence
- LCDs have several advantages including slimness, light weight, low power consumption characteristics.
- the LCD displays information using electrical and optical properties of liquid crystal molecules.
- the LCD itself is a non-luminous device that displays images using a light source such as a lamp.
- the LCD essentially needs a separate unit for irradiating light, i.e., a backlight assembly because the liquid crystal molecules injected between a thin film transistor (TFT) substrate and a color filter substrate does not emit light on their own.
- TFT thin film transistor
- a backlight assembly includes a mold frame having a receiving space, a reflector mounted on the lowest surface of the receiving space for reflecting light toward liquid crystal display panel, a light guide plate disposed on the reflector for guiding light, a lamp unit disposed between the light guide plate and a sidewall of the receiving space for emitting light, optical sheets stacked on the light guide plate for diffusing and focusing light, and a top chassis disposed on the mold frame and enclosing the liquid crystal display from a predetermined portion of the edge of the liquid crystal display panel to a side portion of the mold frame.
- the optical sheets include a diffusion sheet for diffusing light, a prism sheet disposed on the diffusion sheet for focusing the diffused light and transferring the focused light to the liquid crystal display panel, and a protection sheet for protecting the diffusion sheet and the prism sheet.
- FIG. 1 is a sectional view of a related art LCD.
- the related art LCD includes a backlight assembly 50 for generating light, and a display unit 40 , which receives the light from the backlight assembly 50 and displays images.
- the backlight assembly 50 includes a lamp unit 51 for generating light and a light guide unit for guiding the light generated by the lamp unit 51 toward a liquid crystal display panel 10 .
- the display unit 40 includes the liquid crystal display panel 10 and an upper polarizer 30 and a lower polarizer 20 respectively disposed on an upper surface and a lower surface of the liquid crystal display panel 10 .
- the liquid crystal display panel 10 includes a TFT substrate 11 and a color filter substrate 12 each having an electrode formed thereon.
- the lamp unit 51 includes a lamp 51 a for generating light and a lamp reflector 51 b enclosing the lamp 51 a .
- the light generated by the lamp 51 a is incident into a light guide plate 52 to be described later.
- the lamp reflector 51 b reflects the light generated by the lamp 51 a toward the light guide plate 52 , thereby increasing amount of incident light toward the light guide plate 52 .
- the light guide unit includes a reflection plate 54 , the light guide plate 52 , and optical sheets 53 .
- the light guide plate 52 is disposed at one end of the lamp unit 51 to guide the light emitted from the lamp unit 51 such that the light emitted from the lamp unit 51 is incident into the LCD panel 10 .
- the reflection plate 54 is disposed beneath the light guide plate 52 and reflects light leaked from the light guide plate 52 toward the light guide plate 52 again.
- the plurality of optical sheets 53 are disposed on the light guide plate 52 to enhance efficiency of the light passing through the light guide plate 52 .
- the optical sheets 53 include a diffusion sheet 53 a , a prism sheet 53 b and a protection sheet 53 c , and are orderly stacked on the light guide plate 52 .
- the diffusion sheet 53 a scatters the light that is incident from the light guide plate 52 , thereby making the brightness distribution of the light uniform.
- the prism sheet 53 b includes a plurality of prisms formed repeatedly on an upper surface thereof and focuses the light diffused by the diffusion sheet 53 a in a direction perpendicular to a plane of the LCD panel 10 . Accordingly, the light that has passed through the prism sheet 53 b mostly advances in a direction perpendicular to the plane of the LCD panel 10 , thereby obtaining a uniform distribution.
- the protection sheet 53 c provided on the prism sheet 53 b functions not only to protect the upper surface of the prism sheet 53 b , but also to diffuse light so as to make the distribution of the light that is incident from the prism sheet 53 b uniform.
- FIGS. 2A and 2B are a sectional view and a perspective view of the prism sheet illustrated in FIG. 1 respectively.
- the related art prism sheet 200 includes a body part 210 , through which the light diffused by the light guide plate and the diffusion sheet is initially introduced, and a protrusion part 220 shaped in a isosceles triangle prism, for maintaining path of the diffused light constantly.
- the protrusion part 220 has a plurality of isosceles triangle prisms linearly arranged in a stripe form.
- the protrusion part 220 shaped in the isosceles triangle prism has a pitch ranging from a few tens ⁇ m to a few hundreds ⁇ m, and an apex angle ⁇ ranging from 60 degrees to 130 degrees.
- the apex angle ⁇ is an acute angle, the brightness increases but the viewing angle decreases.
- the prism sheet 200 focuses the diffused light introduced into the body part 210 by refracting the diffused light toward the front side, but the light that is introduced into inclined surfaces of the protrusion part 220 does not contribute to the enhancement of the front brightness and is lost due to the inner full reflection.
- the prism sheet may be arranged such that the protrusion part 220 is directed toward the light guide plate.
- such an arrangement enhances the front brightness, but decreases the viewing angle, which is counter to use in the flat panel displays requiring a wide viewing angle, such as a home television.
- the present invention is directed to a backlight assembly of an LCD that substantially obviates one or more problems due to limitations and disadvantages of the related art.
- An advantage of the present invention is to provide a backlight assembly with an improved prism sheet, the prism sheet having a plurality of protrusion parts formed on one side thereof with a concavely inclined surface.
- a backlight assembly of an LCD comprising: a lamp for generating a light; a light guide plate disposed at a side of the lamp, for guiding the light; and a diffusion sheet and a prism sheet disposed on the light guide plate, for enhancing efficiency of the light outputted from the light guide plate, wherein the prism sheet comprises a body part and a plurality of protrusion parts each having a concavely inclined surface formed on the body part.
- each of the protrusion parts may be a circular arc surface formed when two circular cylinders having an identical radius ‘r’ overlap with each other, and an apex point ‘a’ of the each of the protrusion parts is one of two contact points of the two circular cylinders overlapping with each other, which is equal to or is leveled lower than a position of a center ‘O’ of a section of the circular cylinder.
- the plurality of protrusion parts may extend from one end of the body part to the other end of the body part opposing the one end of the body part and are formed linearly in parallel with one another.
- the prism sheet may be formed of a transparent resin material.
- the transparent resin material is acryl or polycarbonate.
- An angle ‘ ⁇ ’ between a first line parallel to a plane of the body part and a second line connecting a center ‘O’ of any of the two circular cylinders with the apex point ‘a’ of the protrusion part has a relationship of 0° ⁇ 90°.
- a distance between the adjacent apex points of the protrusion parts is equal to or less than (cos ⁇ +1) times as much as the radius of any of the two circular cylinders.
- the protrusion may have a height less than 300 ⁇ m.
- the backlight assembly may further include a retreating sheet disposed on the prism sheet, for retreating the light that is incident from the prism sheet.
- the prism sheet may be disposed such that the protrusion part faces the diffusion sheet. Or, the prism sheet may be disposed such that the body part faces the diffusion sheet.
- the prism sheet may include two prism sheets each having the protrusion part, which is disposed with an angle ranging from 0 degree to 90 degrees.
- a backlight assembly of an LCD comprising: a lamp for generating a light; a light guide plate disposed at a side of the lamp, for guiding the light; and a diffusion sheet disposed on the light guide plate, for scattering the light that is incident from the light guide plate to make brightness distribution of the light uniform; a prism sheet disposed on the diffusion sheet and having a plurality of protrusion parts having a concavely inclined surface and arranged in a stripe form; and a retreating sheet disposed on the prism sheet, for retreating the light that is incident from the prism sheet.
- FIG. 1 is a sectional view of a related art LCD
- FIGS. 2A and 2B are a sectional view and a perspective view of the prism sheet illustrated in FIG. 1 respectively;
- FIGS. 3A , 3 B and 3 C are sectional views of backlight assemblies of an LCD according to the present invention.
- FIG. 4 is a schematic view illustrating refraction of light that is incident into a concave lens
- FIG. 5 is a perspective view of a backlight assembly of an LCD according to an embodiment of the present invention.
- FIGS. 6A and 6B are a sectional view and a perspective view of the prism sheet illustrated in FIG. 3 .
- FIGS. 3A , 3 B and 3 C are sectional views of backlight assemblies of an LCD according to the present invention.
- each of the backlight assemblies 300 includes a lamp unit 310 for generating light and a light guide unit for guiding the light generated by the lamp unit 310 toward a liquid crystal display panel.
- a prism sheet is formed of a transparent resin material such as acryl, polycarbonate or the like, and has a plurality of protrusion parts arranged in a stripe form, i.e., in a linear form, each of the protrusion parts having a concavely inclined surface formed on one surface thereof.
- the inclined surface of each of the protrusion parts formed on an upper surface of the prism sheet is a substantially circular arc surface formed when two circular cylinders having an equal radius ‘r’ overlap with each other, and apex point ‘a’ of the each of the protrusion parts is one of two contact points of the two circular cylinders overlapping with each other, and is located equal to or lower than center ‘O’ of a cross section of the circular cylinder.
- the circular cylinders are introduced so as to design the shape of the protrusion parts and are not provided on the actual prism sheet.
- the lamp unit 310 includes a lamp 312 for generating light, and a lamp reflector 314 enclosing the lamp 312 .
- the light generated by the lamp 312 is incident into a light guide plate 320 .
- the lamp reflector 314 reflects the light generated by the lamp 312 toward the light guide plate 320 , thereby increasing amount of incident light toward the light guide plate 320 , which is like in the general lamp unit.
- the light guide unit includes a reflection plate 330 , the light guide plate 320 , and optical sheets 340 .
- the light guide plate 320 is disposed at one end of the lamp unit 310 to guide the light emitted from the lamp unit 310 such that the light emitted from the lamp unit 310 is incident into the LCD panel.
- the reflection plate 330 is disposed beneath the light guide plate 320 and reflects light leaked from the light guide plate 320 toward the light guide plate 320 again.
- the plurality of optical sheets 340 are disposed on the light guide plate 320 to enhance efficiency of the light passing through the light guide plate 320 .
- the optical sheets 340 include a diffusion sheet 342 , a prism sheet 344 and a protection/retardation sheet 346 , and are orderly stacked on the light guide plate 320 .
- the diffusion sheet 342 scatters the light that is incident from the light guide plate 320 , thereby making the brightness distribution of the light uniform.
- the prism sheet 344 described above the prism sheet is disposed such that the protrusion parts having concavely inclined surfaces face the diffusion sheet 342 , as illustrated in FIG. 3A , or is disposed such that the face not having the protrusion parts faces the diffusion sheet 342 , as illustrated in FIG. 3B .
- a plurality of protrusion parts 321 are formed on an upper surface of the light guide plate 320 ′, so that about 80% of the light that is incident into the light guide plate 320 ′ is emitted with an angle range of about 60° to 80°.
- the prism sheet 344 of the present invention is disposed such that the surface where the protrusion parts are formed opposes the diffusion sheet 342 as shown in FIG. 3B .
- the light that is incident with the specific angles is refracted in various angles by the concavely inclined surface of the prism sheet 344 , so that uniform optical characteristics in a wide range can be obtained.
- the retardation sheet 346 disposed on the prism sheet 344 functions not only to protect an upper surface of the prism sheet 344 but also to retard the light that is incident from the prism sheet 344 .
- the retardation sheet retards or delays one of primary wave (or push wave) and secondary wave (or shake wave) such that one of the primary wave and the secondary wave is converted into the other, thereby enhancing the brightness. It is noted that the retardation sheet may be eliminated, if necessary.
- FIG. 5 is a perspective view of a backlight assembly of an LCD according to an embodiment of the present invention.
- the same reference numbers as in FIGS. 3A and 3B will be used throughout FIG. 5 to refer to the same or like parts, and their repeated description will be omitted.
- a backlight assembly 300 ′ of an LCD is the same in basic constitution as the backlight assembly 300 illustrated in FIGS. 3A and 3B , but is characterized in that two prism sheets 344 and 344 ′ are provided and are arranged such that protrusion parts of the two prism sheets form an offset angle with respect to each other ranging from about 0 degree to 90 degrees. This is to more effectively focus the light diffused by the diffusion sheet 320 , thereby enhancing the brightness and viewing angle of the LCD panel.
- the two prism sheets 344 and 344 ′ illustrated in FIG. 5 are disposed such that their protrusion parts face the diffusion sheet 320 , they may be disposed such that the body parts of the prism sheets 344 and 344 ′ face the diffusion sheet 320 as shown in FIG. 3B .
- a light guide plate as illustrated in FIG. 3C having a plurality of protrusion parts may be incorporated into the configuration of FIG. 5 having two prism sheets.
- FIGS. 6A and 6B are a sectional view and a perspective view of the prism sheet illustrated in FIG. 3 .
- a prism sheet 500 includes a body part 510 and a plurality of protrusion parts 520 having concavely inclined surfaces 524 formed on an upper surface of the body part 510 .
- the inclined surface 524 of each of the protrusion parts is a substantially circular arc surface formed when two circular cylinders 522 having an equal radius ‘r’ overlap with each other, and apex point ‘a’ of the each of the protrusion parts is one of two contact points of the two circular cylinders 522 overlapping with each other, and is located equal to or lower than center ‘O’ of a cross section of the circular cylinder.
- FIGS. 6A and 6B exemplarily show that the inclined surfaces 524 are formed by overlapping the two circular cylinders having the equal radius ‘r’, such a construction is only one embodiment, and accordingly it will be apparent to those skilled in the art that the two circular cylinders 522 may have different radii.
- the protrusion parts 520 repeatedly form inclined surfaces having an equal curvature along with the circular cylinders 522 having the radius ‘r’ from the apex points ‘a’.
- the circular cylinders 522 are introduced so as to design the shape of the protrusion parts 520 , and are not provided on the actual prism sheet.
- the plurality of protrusion parts 520 may extend from one end of the body part 510 to the other end of the body part 510 opposing the one end of the body part 510 and are formed in parallel with one another in the stripe form.
- the plurality of protrusion parts 520 are formed integrally with the body part 510 .
- the prism sheet 500 is designed such that one surface of a flat film has the shape of the protrusion parts 520 .
- the angle ‘ ⁇ ’ ranges between about 0 degree and about 90 degrees
- the height ‘h’ is less than about 300 ⁇ m
- the pitch ‘p’ is less than or equal to r*(cos ⁇ +1).
- inclined surfaces of protrusion parts of the prism sheet are formed in a concave structure, thereby preventing light efficiency from being lowered and securing a wide viewing angle.
Abstract
A backlight assembly of an LCD is provided. The backlight assembly includes a lamp for generating a light, a light guide plate disposed at a side of the lamp, for guiding the light, and a diffusion sheet and a prism sheet disposed on the light guide plate, for enhancing efficiency of the light outputted from the light guide plate, wherein the prism sheet comprises a body part and a plurality of protrusion parts each having a concavely inclined surface formed on the body part.
Description
- This application claims the benefit of Korean Patent Application No. 2003-79740, filed in Korea on Nov. 12, 2003, which is hereby incorporated by reference for all purposes as if fully set forth herein.
- 1. Field of the Invention
- The present invention relates to a non-luminous flat display device, and more particularly, to a backlight assembly of a liquid crystal display with an improved optical sheet.
- 2. Description of the Related Art
- Recently, a variety of flat panel displays have been developed to reduce weight and volume acting as drawbacks of cathode ray tubes (CRTs). Such flat panel displays include a liquid crystal display (LCD), a field emission display, a plasma display panel (PDP), an electro-luminescence (EL) and the like. Research for enhancing the display quality and increasing the screen size of the flat panel displays is being actively performed.
- Among such flat panel displays, LCDs have several advantages including slimness, light weight, low power consumption characteristics. In particular, the LCD displays information using electrical and optical properties of liquid crystal molecules. The LCD itself is a non-luminous device that displays images using a light source such as a lamp. In other words, unlike in the CRT, the LCD essentially needs a separate unit for irradiating light, i.e., a backlight assembly because the liquid crystal molecules injected between a thin film transistor (TFT) substrate and a color filter substrate does not emit light on their own.
- In general, a backlight assembly includes a mold frame having a receiving space, a reflector mounted on the lowest surface of the receiving space for reflecting light toward liquid crystal display panel, a light guide plate disposed on the reflector for guiding light, a lamp unit disposed between the light guide plate and a sidewall of the receiving space for emitting light, optical sheets stacked on the light guide plate for diffusing and focusing light, and a top chassis disposed on the mold frame and enclosing the liquid crystal display from a predetermined portion of the edge of the liquid crystal display panel to a side portion of the mold frame.
- The optical sheets include a diffusion sheet for diffusing light, a prism sheet disposed on the diffusion sheet for focusing the diffused light and transferring the focused light to the liquid crystal display panel, and a protection sheet for protecting the diffusion sheet and the prism sheet.
-
FIG. 1 is a sectional view of a related art LCD. - Referring to
FIG. 1 , the related art LCD includes abacklight assembly 50 for generating light, and adisplay unit 40, which receives the light from thebacklight assembly 50 and displays images. Thebacklight assembly 50 includes alamp unit 51 for generating light and a light guide unit for guiding the light generated by thelamp unit 51 toward a liquidcrystal display panel 10. - The
display unit 40 includes the liquidcrystal display panel 10 and anupper polarizer 30 and alower polarizer 20 respectively disposed on an upper surface and a lower surface of the liquidcrystal display panel 10. The liquidcrystal display panel 10 includes a TFT substrate 11 and acolor filter substrate 12 each having an electrode formed thereon. - Specifically, the
lamp unit 51 includes alamp 51 a for generating light and alamp reflector 51 b enclosing thelamp 51 a. The light generated by thelamp 51 a is incident into alight guide plate 52 to be described later. Thelamp reflector 51 b reflects the light generated by thelamp 51 a toward thelight guide plate 52, thereby increasing amount of incident light toward thelight guide plate 52. - The light guide unit includes a
reflection plate 54, thelight guide plate 52, andoptical sheets 53. Thelight guide plate 52 is disposed at one end of thelamp unit 51 to guide the light emitted from thelamp unit 51 such that the light emitted from thelamp unit 51 is incident into theLCD panel 10. - The
reflection plate 54 is disposed beneath thelight guide plate 52 and reflects light leaked from thelight guide plate 52 toward thelight guide plate 52 again. - The plurality of
optical sheets 53 are disposed on thelight guide plate 52 to enhance efficiency of the light passing through thelight guide plate 52. Specifically, theoptical sheets 53 include adiffusion sheet 53 a, aprism sheet 53 b and aprotection sheet 53 c, and are orderly stacked on thelight guide plate 52. - The
diffusion sheet 53 a scatters the light that is incident from thelight guide plate 52, thereby making the brightness distribution of the light uniform. Theprism sheet 53 b includes a plurality of prisms formed repeatedly on an upper surface thereof and focuses the light diffused by thediffusion sheet 53 a in a direction perpendicular to a plane of theLCD panel 10. Accordingly, the light that has passed through theprism sheet 53 b mostly advances in a direction perpendicular to the plane of theLCD panel 10, thereby obtaining a uniform distribution. - The
protection sheet 53 c provided on theprism sheet 53 b functions not only to protect the upper surface of theprism sheet 53 b, but also to diffuse light so as to make the distribution of the light that is incident from theprism sheet 53 b uniform. -
FIGS. 2A and 2B are a sectional view and a perspective view of the prism sheet illustrated inFIG. 1 respectively. - Referring to
FIGS. 2A and 2B , the relatedart prism sheet 200 includes abody part 210, through which the light diffused by the light guide plate and the diffusion sheet is initially introduced, and aprotrusion part 220 shaped in a isosceles triangle prism, for maintaining path of the diffused light constantly. Theprotrusion part 220 has a plurality of isosceles triangle prisms linearly arranged in a stripe form. - The
protrusion part 220 shaped in the isosceles triangle prism has a pitch ranging from a few tens μm to a few hundreds μm, and an apex angle α ranging from 60 degrees to 130 degrees. When the apex angle α is an acute angle, the brightness increases but the viewing angle decreases. - Also, when the
protrusion part 220 of the isosceles triangle prism is installed directing toward the front side of the LCD panel, theprism sheet 200 focuses the diffused light introduced into thebody part 210 by refracting the diffused light toward the front side, but the light that is introduced into inclined surfaces of theprotrusion part 220 does not contribute to the enhancement of the front brightness and is lost due to the inner full reflection. - To overcome this drawback, the prism sheet may be arranged such that the
protrusion part 220 is directed toward the light guide plate. However, such an arrangement enhances the front brightness, but decreases the viewing angle, which is counter to use in the flat panel displays requiring a wide viewing angle, such as a home television. - Accordingly, the present invention is directed to a backlight assembly of an LCD that substantially obviates one or more problems due to limitations and disadvantages of the related art.
- An advantage of the present invention is to provide a backlight assembly with an improved prism sheet, the prism sheet having a plurality of protrusion parts formed on one side thereof with a concavely inclined surface.
- Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
- These objectives and other advantage of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
- To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a backlight assembly of an LCD, comprising: a lamp for generating a light; a light guide plate disposed at a side of the lamp, for guiding the light; and a diffusion sheet and a prism sheet disposed on the light guide plate, for enhancing efficiency of the light outputted from the light guide plate, wherein the prism sheet comprises a body part and a plurality of protrusion parts each having a concavely inclined surface formed on the body part.
- The inclined surface of each of the protrusion parts may be a circular arc surface formed when two circular cylinders having an identical radius ‘r’ overlap with each other, and an apex point ‘a’ of the each of the protrusion parts is one of two contact points of the two circular cylinders overlapping with each other, which is equal to or is leveled lower than a position of a center ‘O’ of a section of the circular cylinder.
- The plurality of protrusion parts may extend from one end of the body part to the other end of the body part opposing the one end of the body part and are formed linearly in parallel with one another.
- The prism sheet may be formed of a transparent resin material. The transparent resin material is acryl or polycarbonate.
- An angle ‘θ’ between a first line parallel to a plane of the body part and a second line connecting a center ‘O’ of any of the two circular cylinders with the apex point ‘a’ of the protrusion part has a relationship of 0°≦θ90°. A distance between the adjacent apex points of the protrusion parts is equal to or less than (cos θ+1) times as much as the radius of any of the two circular cylinders.
- The protrusion may have a height less than 300 μm. The backlight assembly may further include a retreating sheet disposed on the prism sheet, for retreating the light that is incident from the prism sheet.
- The prism sheet may be disposed such that the protrusion part faces the diffusion sheet. Or, the prism sheet may be disposed such that the body part faces the diffusion sheet.
- The prism sheet may include two prism sheets each having the protrusion part, which is disposed with an angle ranging from 0 degree to 90 degrees.
- In another aspect of the present invention, there is provided a backlight assembly of an LCD, comprising: a lamp for generating a light; a light guide plate disposed at a side of the lamp, for guiding the light; and a diffusion sheet disposed on the light guide plate, for scattering the light that is incident from the light guide plate to make brightness distribution of the light uniform; a prism sheet disposed on the diffusion sheet and having a plurality of protrusion parts having a concavely inclined surface and arranged in a stripe form; and a retreating sheet disposed on the prism sheet, for retreating the light that is incident from the prism sheet.
- It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
- The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
-
FIG. 1 is a sectional view of a related art LCD; -
FIGS. 2A and 2B are a sectional view and a perspective view of the prism sheet illustrated inFIG. 1 respectively; -
FIGS. 3A , 3B and 3C are sectional views of backlight assemblies of an LCD according to the present invention; -
FIG. 4 is a schematic view illustrating refraction of light that is incident into a concave lens; -
FIG. 5 is a perspective view of a backlight assembly of an LCD according to an embodiment of the present invention; and -
FIGS. 6A and 6B are a sectional view and a perspective view of the prism sheet illustrated inFIG. 3 . - Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
-
FIGS. 3A , 3B and 3C are sectional views of backlight assemblies of an LCD according to the present invention. Referring toFIGS. 3A and 3B , each of thebacklight assemblies 300 includes alamp unit 310 for generating light and a light guide unit for guiding the light generated by thelamp unit 310 toward a liquid crystal display panel. - In the present invention, it is noted that among
optical sheets 340 provided in the light guide unit, a prism sheet is formed of a transparent resin material such as acryl, polycarbonate or the like, and has a plurality of protrusion parts arranged in a stripe form, i.e., in a linear form, each of the protrusion parts having a concavely inclined surface formed on one surface thereof. - The inclined surface of each of the protrusion parts formed on an upper surface of the prism sheet is a substantially circular arc surface formed when two circular cylinders having an equal radius ‘r’ overlap with each other, and apex point ‘a’ of the each of the protrusion parts is one of two contact points of the two circular cylinders overlapping with each other, and is located equal to or lower than center ‘O’ of a cross section of the circular cylinder.
- In the above, the circular cylinders are introduced so as to design the shape of the protrusion parts and are not provided on the actual prism sheet.
- Snell's law is applied to refraction of light by the structure of the protrusion part having the concavely inclined surface. As a result, the light that is incident into the concavely inclined is refracted in such a manner that the light 400 is widespread from a virtual focus “F,” as illustrated in
FIG. 4 illustrating refraction of light in a concave lens. - Namely, by concavely forming the inclined surface of the protrusion part provided on the prism sheet, it is possible to refract the light introduced into the prism sheet with a predetermined angle, thereby obtaining uniform optical characteristics in a wide range.
- Also, the
lamp unit 310 includes alamp 312 for generating light, and alamp reflector 314 enclosing thelamp 312. The light generated by thelamp 312 is incident into alight guide plate 320. Thelamp reflector 314 reflects the light generated by thelamp 312 toward thelight guide plate 320, thereby increasing amount of incident light toward thelight guide plate 320, which is like in the general lamp unit. - The light guide unit includes a
reflection plate 330, thelight guide plate 320, andoptical sheets 340. Thelight guide plate 320 is disposed at one end of thelamp unit 310 to guide the light emitted from thelamp unit 310 such that the light emitted from thelamp unit 310 is incident into the LCD panel. - The
reflection plate 330 is disposed beneath thelight guide plate 320 and reflects light leaked from thelight guide plate 320 toward thelight guide plate 320 again. - The plurality of
optical sheets 340 are disposed on thelight guide plate 320 to enhance efficiency of the light passing through thelight guide plate 320. Specifically, theoptical sheets 340 include adiffusion sheet 342, aprism sheet 344 and a protection/retardation sheet 346, and are orderly stacked on thelight guide plate 320. - The
diffusion sheet 342 scatters the light that is incident from thelight guide plate 320, thereby making the brightness distribution of the light uniform. - Also, the
prism sheet 344 described above the prism sheet is disposed such that the protrusion parts having concavely inclined surfaces face thediffusion sheet 342, as illustrated inFIG. 3A , or is disposed such that the face not having the protrusion parts faces thediffusion sheet 342, as illustrated inFIG. 3B . - In the embodiment illustrated in
FIG. 3C , a plurality ofprotrusion parts 321 are formed on an upper surface of thelight guide plate 320′, so that about 80% of the light that is incident into thelight guide plate 320′ is emitted with an angle range of about 60° to 80°. - As illustrated in
FIG. 3C , theprism sheet 344 of the present invention is disposed such that the surface where the protrusion parts are formed opposes thediffusion sheet 342 as shown inFIG. 3B . Hence, the light that is incident with the specific angles is refracted in various angles by the concavely inclined surface of theprism sheet 344, so that uniform optical characteristics in a wide range can be obtained. - The
retardation sheet 346 disposed on theprism sheet 344 functions not only to protect an upper surface of theprism sheet 344 but also to retard the light that is incident from theprism sheet 344. - In the retreating of the incident light, which is generated by the
lamp 312 and passes through thelight guide plate 320, thediffusion sheet 342, and theprism sheet 344, the retardation sheet retards or delays one of primary wave (or push wave) and secondary wave (or shake wave) such that one of the primary wave and the secondary wave is converted into the other, thereby enhancing the brightness. It is noted that the retardation sheet may be eliminated, if necessary. -
FIG. 5 is a perspective view of a backlight assembly of an LCD according to an embodiment of the present invention. Wherever possible, the same reference numbers as inFIGS. 3A and 3B will be used throughoutFIG. 5 to refer to the same or like parts, and their repeated description will be omitted. - Referring to
FIG. 5 , abacklight assembly 300′ of an LCD according to an embodiment of the present invention is the same in basic constitution as thebacklight assembly 300 illustrated inFIGS. 3A and 3B , but is characterized in that twoprism sheets diffusion sheet 320, thereby enhancing the brightness and viewing angle of the LCD panel. - Although the two
prism sheets FIG. 5 are disposed such that their protrusion parts face thediffusion sheet 320, they may be disposed such that the body parts of theprism sheets diffusion sheet 320 as shown inFIG. 3B . Moreover, although not illustrated, a light guide plate as illustrated inFIG. 3C having a plurality of protrusion parts may be incorporated into the configuration ofFIG. 5 having two prism sheets. -
FIGS. 6A and 6B are a sectional view and a perspective view of the prism sheet illustrated inFIG. 3 . - Referring to
FIGS. 6A and 6B , aprism sheet 500 according to the present invention includes abody part 510 and a plurality ofprotrusion parts 520 having concavelyinclined surfaces 524 formed on an upper surface of thebody part 510. Theinclined surface 524 of each of the protrusion parts is a substantially circular arc surface formed when twocircular cylinders 522 having an equal radius ‘r’ overlap with each other, and apex point ‘a’ of the each of the protrusion parts is one of two contact points of the twocircular cylinders 522 overlapping with each other, and is located equal to or lower than center ‘O’ of a cross section of the circular cylinder. - Although
FIGS. 6A and 6B exemplarily show that theinclined surfaces 524 are formed by overlapping the two circular cylinders having the equal radius ‘r’, such a construction is only one embodiment, and accordingly it will be apparent to those skilled in the art that the twocircular cylinders 522 may have different radii. - The
protrusion parts 520 repeatedly form inclined surfaces having an equal curvature along with thecircular cylinders 522 having the radius ‘r’ from the apex points ‘a’. - In the above, the
circular cylinders 522 are introduced so as to design the shape of theprotrusion parts 520, and are not provided on the actual prism sheet. - The plurality of
protrusion parts 520 may extend from one end of thebody part 510 to the other end of thebody part 510 opposing the one end of thebody part 510 and are formed in parallel with one another in the stripe form. - Also, it is desirable that the plurality of
protrusion parts 520 are formed integrally with thebody part 510. In other words, theprism sheet 500 is designed such that one surface of a flat film has the shape of theprotrusion parts 520. - As aforementioned, when light is incident into the concavely
inclined surfaces 524 of theprotrusion parts 520 of theprism sheet 520, the light is refracted in various directions, so that uniform optical characteristics in a wide range can be obtained and a wide viewing angle characteristic can be secured. - In other words, in the related art prism sheet shaped in the triangular prism, as the acute angle α of the apex point is reduced, the brightness increases but the viewing angle decreases. However, in the present invention, due to the acute angle of the apex point ‘a’, high brightness is obtained and also due to the
protrusion structure 520 having the concavelyinclined surface 524, incident light can be refracted in various directions so that a wide viewing angle characteristic is obtained. - Again referring to
FIG. 6A , when it is assumed that height of each of theprotrusion parts 520 is h, an angle between a first line parallel to the flat surface of theprism sheet 510 is ‘θ’, and a distance between theprotrusions 520 is a pitch (p), p is a distance between the adjacent apex points ‘a’. - In the present invention, the angle ‘θ’ ranges between about 0 degree and about 90 degrees, the height ‘h’ is less than about 300 μm, and the pitch ‘p’ is less than or equal to r*(cos θ+1). The above definitions may be expressed by equations below:
-
0°≦θ<90°, -
h<300 μm, and -
p≦r*(cos θ+1). - In conclusion, in the fabrication of the prism sheet of the backlight assembly of the LCD according to the present invention, by adjusting refractive index of the prism sheet material, θ value related with distribution of angles of incident light, radius of circular cylinders, and distance between protrusion parts, it becomes possible to obtain suitable optical characteristics for the brightness and viewing angle.
- As described above, according to the inventive backlight assembly of an LCD, inclined surfaces of protrusion parts of the prism sheet are formed in a concave structure, thereby preventing light efficiency from being lowered and securing a wide viewing angle.
- It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
Claims (2)
1. A backlight assembly of an LCD, comprising:
a lamp for generating a light;
a light guide plate disposed at a side of the lamp, for guiding the light; and
a diffusion sheet and a prism sheet disposed on the light guide plate, for enhancing efficiency of the light outputted from the light guide plate, wherein the prism sheet comprises a body part and a plurality of protrusion parts each having a concavely inclined surface formed on the body part.
2-35. (canceled)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/987,674 US20080239756A1 (en) | 2003-11-12 | 2007-12-03 | Backlight assembly of liquid crystal display |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR2003-0079740 | 2003-11-12 | ||
KR1020030079740A KR100725011B1 (en) | 2003-11-12 | 2003-11-12 | Prism sheet and back light assembly |
US10/949,243 US7303323B2 (en) | 2003-11-12 | 2004-09-27 | Backlight assembly of liquid crystal display |
US11/987,674 US20080239756A1 (en) | 2003-11-12 | 2007-12-03 | Backlight assembly of liquid crystal display |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/949,243 Continuation US7303323B2 (en) | 2003-11-12 | 2004-09-27 | Backlight assembly of liquid crystal display |
Publications (1)
Publication Number | Publication Date |
---|---|
US20080239756A1 true US20080239756A1 (en) | 2008-10-02 |
Family
ID=34545858
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/949,243 Expired - Fee Related US7303323B2 (en) | 2003-11-12 | 2004-09-27 | Backlight assembly of liquid crystal display |
US11/987,674 Abandoned US20080239756A1 (en) | 2003-11-12 | 2007-12-03 | Backlight assembly of liquid crystal display |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/949,243 Expired - Fee Related US7303323B2 (en) | 2003-11-12 | 2004-09-27 | Backlight assembly of liquid crystal display |
Country Status (5)
Country | Link |
---|---|
US (2) | US7303323B2 (en) |
JP (1) | JP2005150116A (en) |
KR (1) | KR100725011B1 (en) |
CN (1) | CN100397184C (en) |
TW (1) | TWI315428B (en) |
Families Citing this family (39)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100725011B1 (en) * | 2003-11-12 | 2007-06-04 | 엘지전자 주식회사 | Prism sheet and back light assembly |
JP2005234402A (en) * | 2004-02-20 | 2005-09-02 | Citizen Electronics Co Ltd | Backlight |
US20060083004A1 (en) * | 2004-10-15 | 2006-04-20 | Eastman Kodak Company | Flat-panel area illumination system |
US20060103777A1 (en) * | 2004-11-15 | 2006-05-18 | 3M Innovative Properties Company | Optical film having a structured surface with rectangular based prisms |
US7320538B2 (en) * | 2004-12-30 | 2008-01-22 | 3M Innovative Properties Company | Optical film having a structured surface with concave pyramid-shaped structures |
US7416309B2 (en) * | 2004-12-30 | 2008-08-26 | 3M Innovative Properties Company | Optical film having a surface with rounded structures |
US7220026B2 (en) * | 2004-12-30 | 2007-05-22 | 3M Innovative Properties Company | Optical film having a structured surface with offset prismatic structures |
US20060250707A1 (en) * | 2005-05-05 | 2006-11-09 | 3M Innovative Properties Company | Optical film having a surface with rounded pyramidal structures |
US20070030415A1 (en) * | 2005-05-16 | 2007-02-08 | Epstein Kenneth A | Back-lit displays with high illumination uniformity |
CN100389348C (en) * | 2005-06-01 | 2008-05-21 | 友达光电股份有限公司 | Backlight module with holographic diffusion plate |
JP2006350177A (en) * | 2005-06-20 | 2006-12-28 | Seiko Epson Corp | Manufacturing method of optical sheet, optical sheet, planar lighting device, and electrooptical apparatus |
KR101201306B1 (en) * | 2005-06-29 | 2012-11-14 | 엘지디스플레이 주식회사 | Back light unit |
TWM282184U (en) * | 2005-07-22 | 2005-12-01 | Innolux Display Corp | Light guide plate and backlight module using the same |
US20070024994A1 (en) * | 2005-07-29 | 2007-02-01 | 3M Innovative Properties Company | Structured optical film with interspersed pyramidal structures |
CN100445831C (en) * | 2005-08-24 | 2008-12-24 | 财团法人工业技术研究院 | Flat light source module |
CN100440001C (en) * | 2005-09-16 | 2008-12-03 | 财团法人工业技术研究院 | Intensifying module and light source device |
US7568820B2 (en) * | 2005-10-14 | 2009-08-04 | Dai Nippon Printing Co., Ltd. | Light-controlling sheet and surface illuminant unit |
JP5052797B2 (en) * | 2006-02-14 | 2012-10-17 | 古河電気工業株式会社 | Optical function sheet |
KR100739797B1 (en) * | 2006-02-23 | 2007-07-13 | 삼성전자주식회사 | Display device using a outside light |
KR100770929B1 (en) * | 2006-05-26 | 2007-10-26 | 삼성전자주식회사 | Light guide panel and backlight unit using the same |
US20080002256A1 (en) * | 2006-06-30 | 2008-01-03 | 3M Innovative Properties Company | Optical article including a beaded layer |
US7478913B2 (en) * | 2006-11-15 | 2009-01-20 | 3M Innovative Properties | Back-lit displays with high illumination uniformity |
US7766528B2 (en) * | 2006-11-15 | 2010-08-03 | 3M Innovative Properties Company | Back-lit displays with high illumination uniformity |
US7789538B2 (en) * | 2006-11-15 | 2010-09-07 | 3M Innovative Properties Company | Back-lit displays with high illumination uniformity |
US20080111947A1 (en) * | 2006-11-15 | 2008-05-15 | 3M Innovative Properties Company | Back-lit displays with high illumination uniformity |
KR20090085099A (en) * | 2006-11-15 | 2009-08-06 | 쓰리엠 이노베이티브 프로퍼티즈 컴파니 | Back-lit displays with high illumination uniformity |
KR100802998B1 (en) * | 2006-12-01 | 2008-02-14 | 미래나노텍(주) | Optical sheet having a pattern for suppressing moire in backlight assembly |
CN101393288A (en) * | 2007-09-21 | 2009-03-25 | 鸿富锦精密工业(深圳)有限公司 | Back light module unit and prismatic lens thereof |
KR100974091B1 (en) * | 2007-12-28 | 2010-08-06 | 웅진케미칼 주식회사 | Optical film controlled prism shape and preparing thereof |
TWI418895B (en) * | 2010-03-10 | 2013-12-11 | Coretronic Corp | Backlight module and stereo display apparatus |
TW201131209A (en) * | 2010-03-10 | 2011-09-16 | Core Flex Optical Suzhou Co Ltd | Beam splitting film, backlight module, and stereo display apparatus |
TW201133082A (en) * | 2010-03-18 | 2011-10-01 | Coretronic Corp | Backlight module, stereo display apparatus, and beam splitting film |
WO2012164795A1 (en) * | 2011-05-31 | 2012-12-06 | 三菱電機株式会社 | Backlight and liquid crystal display device |
US20140140091A1 (en) | 2012-11-20 | 2014-05-22 | Sergiy Victorovich Vasylyev | Waveguide illumination system |
TWI476449B (en) * | 2012-04-24 | 2015-03-11 | Univ Minghsin Sci & Tech | Naked-eye 3-d rear projection display device |
KR101980698B1 (en) * | 2012-10-15 | 2019-05-22 | 삼성디스플레이 주식회사 | Prism sheet, back light unit and manufacturing method thereof |
TWI472844B (en) * | 2012-12-27 | 2015-02-11 | Au Optronics Corp | Backlight module adjusting light pattern |
JP5867740B2 (en) * | 2013-04-26 | 2016-02-24 | コニカミノルタ株式会社 | Light emitting device and image forming apparatus |
KR102227691B1 (en) * | 2014-09-30 | 2021-03-12 | 엘지디스플레이 주식회사 | Liquid crystal display device |
Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3846012A (en) * | 1973-11-14 | 1974-11-05 | Qantix Corp | Transparent front projection screen having concave ridges thereon |
US6002829A (en) * | 1992-03-23 | 1999-12-14 | Minnesota Mining And Manufacturing Company | Luminaire device |
US6075649A (en) * | 1998-04-22 | 2000-06-13 | Dai Nippon Printing Co., Ltd. | Lens film and planar light source apparatus |
US6084713A (en) * | 1995-01-18 | 2000-07-04 | Rosenthal; Bruce A. | Lenticular optical system |
US6199992B1 (en) * | 1997-03-13 | 2001-03-13 | Alps Electric Co., Ltd. | Reflector, method of manufacturing the same, and display device using the reflector |
US6241363B1 (en) * | 2000-02-04 | 2001-06-05 | Ching-Chuan Lee | Colored light mixing device |
US6280063B1 (en) * | 1997-05-09 | 2001-08-28 | 3M Innovative Properties Company | Brightness enhancement article |
US6285425B1 (en) * | 1998-06-29 | 2001-09-04 | Motorola, Inc. | Ridged reflector for an optical display having a curved and a planar facet for each ridge |
US6414735B1 (en) * | 1998-12-14 | 2002-07-02 | Lg. Philips Lcd Co., Ltd. | Reflectance liquid crystal display having a limited interference effect |
US6576887B2 (en) * | 2001-08-15 | 2003-06-10 | 3M Innovative Properties Company | Light guide for use with backlit display |
US6611303B1 (en) * | 1999-06-07 | 2003-08-26 | Lg. Philips Lcd Co., Ltd | Backlight device for a liquid crystal display device |
US6845212B2 (en) * | 1999-10-08 | 2005-01-18 | 3M Innovative Properties Company | Optical element having programmed optical structures |
US6869195B2 (en) * | 2003-03-12 | 2005-03-22 | Avery Dennison Corporation | Rear projection screens and methods of making the same |
US7303323B2 (en) * | 2003-11-12 | 2007-12-04 | Lg Electronics Inc. | Backlight assembly of liquid crystal display |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2248638A (en) * | 1937-02-22 | 1941-07-08 | Merton Thomas Ralph | Sheet material with prismatic surfaces |
US4542449A (en) * | 1983-08-29 | 1985-09-17 | Canadian Patents & Development Limited | Lighting panel with opposed 45° corrugations |
US5056892A (en) * | 1985-11-21 | 1991-10-15 | Minnesota Mining And Manufacturing Company | Totally internally reflecting thin, flexible film |
CA1279783C (en) * | 1985-11-21 | 1991-02-05 | Minnesota Mining And Manufacturing Company | Totally internally reflecting thin, flexible film |
US5394255A (en) * | 1992-01-27 | 1995-02-28 | Sekisui Kagaku Kogyo Kabushiki Kaisha | Liquid crystal display using a plurality of light adjusting sheets angled at 5 degrees or more |
KR0168879B1 (en) * | 1992-12-25 | 1999-04-15 | 기따지마 요시또시 | Renticular lens, surface light source and liquid crystal display apparatus |
JPH071428U (en) * | 1993-06-04 | 1995-01-10 | 株式会社エンプラス | Surface light source |
JP3653308B2 (en) * | 1995-08-01 | 2005-05-25 | 日東樹脂工業株式会社 | Surface light source device and liquid crystal display |
JP3607759B2 (en) * | 1995-09-08 | 2005-01-05 | 五洋紙工株式会社 | Prism sheet |
KR19990082166A (en) | 1996-02-01 | 1999-11-25 | 다구치 에이치 | Surface light source element and liquid crystal display device, display device and traffic sign device using same |
US5838403A (en) * | 1996-02-14 | 1998-11-17 | Physical Optics Corporation | Liquid crystal display system with internally reflecting waveguide for backlighting and non-Lambertian diffusing |
KR100271672B1 (en) * | 1998-05-20 | 2000-11-15 | 구본준 | Sheet type optical device and backlight unit using the same |
KR100468815B1 (en) * | 2000-07-20 | 2005-01-31 | 레이젠 주식회사 | a intaglio backlight and that is to produce method |
EP1241514A3 (en) * | 2001-03-16 | 2003-09-10 | Nitto Denko Corporation | Liquid-crystal display apparatus |
TWI258023B (en) | 2001-11-07 | 2006-07-11 | Ibm | A prism sheet, a back-light unit using said prism sheet, and a transmission type liquid crystal display device |
KR100827962B1 (en) * | 2001-11-08 | 2008-05-08 | 엘지디스플레이 주식회사 | liquid crystal display devices and manufacturing method of the same |
-
2003
- 2003-11-12 KR KR1020030079740A patent/KR100725011B1/en not_active IP Right Cessation
-
2004
- 2004-09-21 TW TW093128644A patent/TWI315428B/en not_active IP Right Cessation
- 2004-09-27 US US10/949,243 patent/US7303323B2/en not_active Expired - Fee Related
- 2004-11-12 JP JP2004329627A patent/JP2005150116A/en active Pending
- 2004-11-12 CN CNB2004100957832A patent/CN100397184C/en not_active Expired - Fee Related
-
2007
- 2007-12-03 US US11/987,674 patent/US20080239756A1/en not_active Abandoned
Patent Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3846012A (en) * | 1973-11-14 | 1974-11-05 | Qantix Corp | Transparent front projection screen having concave ridges thereon |
US6002829A (en) * | 1992-03-23 | 1999-12-14 | Minnesota Mining And Manufacturing Company | Luminaire device |
US6084713A (en) * | 1995-01-18 | 2000-07-04 | Rosenthal; Bruce A. | Lenticular optical system |
US6199992B1 (en) * | 1997-03-13 | 2001-03-13 | Alps Electric Co., Ltd. | Reflector, method of manufacturing the same, and display device using the reflector |
US6280063B1 (en) * | 1997-05-09 | 2001-08-28 | 3M Innovative Properties Company | Brightness enhancement article |
US6075649A (en) * | 1998-04-22 | 2000-06-13 | Dai Nippon Printing Co., Ltd. | Lens film and planar light source apparatus |
US6285425B1 (en) * | 1998-06-29 | 2001-09-04 | Motorola, Inc. | Ridged reflector for an optical display having a curved and a planar facet for each ridge |
US6414735B1 (en) * | 1998-12-14 | 2002-07-02 | Lg. Philips Lcd Co., Ltd. | Reflectance liquid crystal display having a limited interference effect |
US6611303B1 (en) * | 1999-06-07 | 2003-08-26 | Lg. Philips Lcd Co., Ltd | Backlight device for a liquid crystal display device |
US6845212B2 (en) * | 1999-10-08 | 2005-01-18 | 3M Innovative Properties Company | Optical element having programmed optical structures |
US6241363B1 (en) * | 2000-02-04 | 2001-06-05 | Ching-Chuan Lee | Colored light mixing device |
US6576887B2 (en) * | 2001-08-15 | 2003-06-10 | 3M Innovative Properties Company | Light guide for use with backlit display |
US6869195B2 (en) * | 2003-03-12 | 2005-03-22 | Avery Dennison Corporation | Rear projection screens and methods of making the same |
US7303323B2 (en) * | 2003-11-12 | 2007-12-04 | Lg Electronics Inc. | Backlight assembly of liquid crystal display |
Also Published As
Publication number | Publication date |
---|---|
US7303323B2 (en) | 2007-12-04 |
KR20050045602A (en) | 2005-05-17 |
JP2005150116A (en) | 2005-06-09 |
TW200516322A (en) | 2005-05-16 |
US20050099823A1 (en) | 2005-05-12 |
CN100397184C (en) | 2008-06-25 |
TWI315428B (en) | 2009-10-01 |
KR100725011B1 (en) | 2007-06-04 |
CN1617026A (en) | 2005-05-18 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7303323B2 (en) | Backlight assembly of liquid crystal display | |
US7645057B2 (en) | Optical sheet and backlight assembly of liquid crystal display with the same | |
US7309149B2 (en) | Prism sheet, backlight assembly and liquid crystal display device having the same | |
US20060087743A1 (en) | Backlight assembly of liquid crystal display | |
KR100898100B1 (en) | Prism sheet | |
KR100903028B1 (en) | Light guide panel comprising wedge type rear prism for back light unit of tft-lcd | |
US8272773B2 (en) | Illuminating device and display device | |
US8605233B2 (en) | Light guide panel for LCD back light unit and LCD back light unit thereby | |
US6095656A (en) | Backlighting apparatus and display apparatus using the same | |
US20060209562A1 (en) | Optical sheet and backlight unit having the same | |
US20060039073A1 (en) | Prism sheet of liquid crystal display and back light unit using the same | |
TWI460503B (en) | Backlight unit | |
US20070002586A1 (en) | Prism sheet, back light unit using the same and liquid crystal display device having the back light unit | |
US20060291253A1 (en) | Light-guide plate, backlight assembly and liquid crystal display device having the same | |
US20080043172A1 (en) | Backlight assembly and display apparatus having the same | |
WO2009141953A1 (en) | Liquid crystal display device | |
US7787074B2 (en) | Optical sheet, backlight unit, and liquid crystal display | |
JP4815930B2 (en) | Light transmissive film, backlight device, and liquid crystal display device | |
US7524099B2 (en) | Liquid crystal display | |
KR20070021378A (en) | Back light assembly and liquid crystal display having the same | |
US20070002585A1 (en) | Backlight unit | |
KR20090027395A (en) | Prism sheet having prisms of zig-zag arrangement patterns, back light unit having the prism sheet and liquid crystal display device having the back light unit | |
KR100807296B1 (en) | backlight for liquid crystal display devices | |
US20120039078A1 (en) | Lighting device and displaying device | |
CN114967224B (en) | Backlight module and display device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |