US20040233508A1 - Electrically addressable optical devices using a system of composite layered flakes suspended in a fluid host to obtain angularly dependent optical effects - Google Patents
Electrically addressable optical devices using a system of composite layered flakes suspended in a fluid host to obtain angularly dependent optical effects Download PDFInfo
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- US20040233508A1 US20040233508A1 US10/441,453 US44145303A US2004233508A1 US 20040233508 A1 US20040233508 A1 US 20040233508A1 US 44145303 A US44145303 A US 44145303A US 2004233508 A1 US2004233508 A1 US 2004233508A1
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- 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
- G02F1/17—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 variable-absorption elements not provided for in groups G02F1/015 - G02F1/169
- G02F1/172—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 variable-absorption elements not provided for in groups G02F1/015 - G02F1/169 based on a suspension of orientable dipolar particles, e.g. suspended particles displays
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- the present invention relates to optical devices having electrically addressable composite layered flakes with angularly dependent optical properties in a system including the flakes and a host fluid.
- the composite flakes have a plurality of layers of different materials, such as dielectric, conductive and polymer liquid crystalline materials.
- the optical properties are electrically selectable or addressable by an electric field applied toward the flake/host system.
- the composite flakes used in a flake/host system in accordance with the invention may include both dielectric and conductive layers.
- the dielectric layers may include, but are not limited to, materials such as mica, titanium dioxide, rutile, aluminum oxide, silica, magnesium fluoride, polymers, Mylar (polytetrafluorethylene), cellophane, polyester, and polyethylene and polymer liquid crystals (PLC's).
- Metals such as gold, silver, aluminum, tin, and metal oxides such as tin oxide or indium tin oxide may be used as the conductive layer, but the conductive layer is not limited to these materials.
- the angularly dependent optical properties may be obtained in several ways: (1) one or more of the layers can be liquid crystalline; (2) two or more layers can reflect light, causing optical interference effects as determined by the index of refraction and the thickness of the layers; (3) one or more layers can contain holograms; (4) any combination of these methods can be used.
- angularly dependent optical effects are often desired, there are conditions in which it is preferable to suppress or alter the angular dependence.
- This suppression of angular dependence can be achieved by preparing composite flakes with a specifically colored layer, such as a dyed polymer, coated with a layer having angularly dependent optical properties, such as a liquid crystal, and utilizing additive and/or subtractive color effects.
- the composite flake reflects a specific color when it is illuminated and viewed normally. However when the composite flake is viewed off-axis, the constant color reflecting from the bottom layer compensates for the shifting color being reflected from the top liquid crystalline layer, minimizing the change/shift in apparent color.
- a specifically colored bottom layer in a composite flake is not limited to suppression of angle-dependent color effects. Specific color combinations can also alter, intensify, and enhance color dependent effects.
- a composite flake may also serve to manipulate the effects of circular polarization that are obtained when polymer cholesteric liquid crystal (PCLC) layers are used.
- PCLC polymer cholesteric liquid crystal
- PCLC's have an inherent optical property known as selective reflection that causes a PCLC layer to reflect only light of a specific wavelength (color) and circular polarization (right- or left-handed).
- the ability to provide polarized light is highly desirable for many applications, particularly those employing three-dimensional effects or tagging for security features. Because selective reflection only reflects one handedness of light, the opposite handedness, or 50% of the light, is not utilized. In applications where brightness of the reflecting layer is a primary concern, it would be useful to manufacture composite flakes possessing two layers of PCLC, with each layer reflecting one of the two polarizations of light, thus maximizing flake reflectivity.
- a metallic layer may be two fold.
- the metallic layer is required to produce the desired optical effect, particularly for “pearl luster” or “pearlescent” pigments.
- pearl luster or “pearlescent” pigments.
- a metallic layer is included in the stack (composition) of layers in a composite flake, it will change the dielectric properties of the flakes. Since the metallic layer is conductive, it significantly alters flake behavior when an electric field is applied.
- the plurality of layers in composite flakes can be dielectric and can be composed of two or more layers.
- dielectric layers can be used to “sandwich” a metal oxide layer or a metal layer.
- One or more of those dielectric layers may be a PLC (either a PCLC, a polymer nematic liquid crystal, or a polymer smectic liquid crystal).
- the flakes may be produced by the methods described in the examples that appear below.
- pearl luster thin film pigments are the traditional pigments based on mica platelets coated with aluminium or bronze layers whose thickness determines the color of the interference effect.
- Multiple layer thin film pigments refer to pigments that use multiple layers (typically dielectric) for interference effects.
- FIG. 1A is a perspective view of a typical irregularly shaped flake which is usable in a flake/host system of an optical device provided by the invention, particularly in a cell containing the system as shown in FIGS. 1B and 1C;
- FIG. 1B is a schematic diagram of a cell incorporating the flake/host system wherein the flakes lie approximately parallel to the cell substrates or walls as occurs when no electric field is applied;
- FIG. 1C is a view similar to FIG. 1B that shows the flakes reoriented with their long axis parallel to a field that is applied perpendicular to the substrates;
- FIG. 2A-2D are sectional views showing composite flakes having different arrangements of layers of different types and materials, the views being taken along the line 2 - 2 in FIG. 1A;
- the basic device 10 embodying the invention represents a cell having a suspension of PCLC flake 12 in host fluid 14 , which provides a flake/host system.
- host fluid 14 which provides a flake/host system.
- Specific examples of such a host fluid that is used when conductivity is desired are propylene carbonate or poly(ethylene glycol). Silicone oils provide an essential nonconductive host fluid.
- a typical device is constructed using an indium tin oxide (ITO) coated glass substrate 16 (in contact with the suspension), though a flexible polymer substrate can also be used. Uniform cell gaps between the substrates 16 may be set by spacers (e.g. beads, fibers, or gaskets), and the device 10 may be filled with the flake/host fluid suspension 14 using capillary action.
- the device 10 may be driven with either a DC or an AC electric field, whereby any periodic waveform can be used as an AC driving field. Waveform bursts or DC spikes may be used prior to or following the main driving waveform to help control or alter flake behavior.
- PCLC flakes 12 in the flake/host fluid system respond to electric fields by rotating about one axis, most commonly that which is parallel to the longest flake dimension.
- a typical flake 12 is shown in FIG. 1A. Flakes lying in the plane defined by the substrate reflect brightly (FIG 1 B), but once they reorient perpendicular to the substrate, little light is reflected (FIG 1 C).
- the preferred host fluid in cases where the flakes are highly dielectric (not conductive) is a moderately conductive host fluid such as propylene carbonate or poly(ethylene glycol).
- a moderately conductive host fluid such as propylene carbonate or poly(ethylene glycol).
- a highly insulating host fluid such as silicone oil is preferred.
- a flake having a two layer cross-section shown in FIG. 2A may include a polymer liquid crystal (PLC) thin film deposited onto a silicon substrate via knife coating, spin coating, dip coating or other coating technologies known to those skilled in the art.
- PLC polymer liquid crystal
- a dielectric layer is deposited onto the existing PLC layer so that the thickness of both layers totals 5-7 ⁇ m.
- dielectric layers on the order of nanometers techniques such as electron beam deposition, chemical vapor deposition, sputter-coating, or dip-coating may be used.
- techniques such as dip-coating, knife-coating or spin-coating may be used. Dielectric layers in both cases may be deposited using other additional techniques know to those skilled in the art.
- the dielectric layer is composed of a material or materials selected from a group of inorganic materials including but not limited to mica, titanium dioxide (rutile), aluminum oxide, silica, and magnesium fluoride or a group of organic polymers including but not limited to Mylar, cellophane, polyester, and polyethylene.
- inorganic materials including but not limited to mica, titanium dioxide (rutile), aluminum oxide, silica, and magnesium fluoride or a group of organic polymers including but not limited to Mylar, cellophane, polyester, and polyethylene.
- Liquid nitrogen is poured over the composite film, and the film fractures due to the large difference in the thermal expansion coefficients of the silicon wafer and the PLC film.
- the flakes are collected by rinsing them off of the substrates and into a storage container with a chemically compatible solvent such as methanol, which can be either evaporated or retained for storage.
- a flake having the two-layer design shown in FIG. 2A with a total thickness of 5-7 ⁇ m may be created using patterning techniques such as the flexible mold substrate described in U.S. patent application Ser. No. 10/383,603, filed Mar. 7, 2003, by Anka Trajkovska-Petkoska et al.
- the PLC material and the mold substrate are heated to a temperature at which the PLC material is soft and sufficiently fluid to be pushed into the wells.
- the PLC can be dissolved in a solvent such as methylene chloride or toluene and poured into the wells, and further processing is continued once the solvent has evaporated.
- a dielectric layer on the order of tens or hundreds of nanometers thick composed of a material or materials selected from a group of inorganic or a group of organic polymers is deposited onto the existing PLC layer as described in Example 1. Alternately, a dielectric layer on the order of micrometers is deposited into the wells and onto the existing PLC layer in a similar manner that the PLC layer is deposited.
- the flakes are released by flexing the mold substrate so that each flake falls out of its well and into a collection container. Loose flakes may also be washed off a substrate with a chemically compatible solvent and stored for further use.
- Flakes having the design shown in FIG. 2A may be produced by depositing a 3-5 ⁇ m thin PLC layer onto an existing dielectric layer consisting of a material selected from a group of inorganic materials including but not limited to mica, titanium dioxide (rutile), aluminum oxide, silica, and magnesium fluoride or a group of organic polymers including but not limited to Mylar, cellophane, polyester, and polyethylene.
- the dielectric layer can be deposited onto a pre-existing substrate such as a silicon wafer, or it can be deposited into wells for a mold substrate. The product flakes after forming are collected as described in previous Examples 1 and 2.
- Flakes having the design shown in FIG. 2B may be produced by depositing a 5-7 ⁇ m PCLC layer onto a silicone substrate as described in Example 1 or the PLC is deposited into wells of a mold substrate as described in Example 2.
- a conductive layer gold, silver, aluminum, tin, etc
- a conductive layer on the order of tens or hundreds of Angstroms is deposited onto the existing PLC layer using techniques such as electron beam deposition, chemical vapor deposition, sputter-coating, or additional coating techniques known to those skilled in the art.
- the flakes are produced, or released as described in Examples 1 and 2 respectively.
- Flakes having the design shown in FIG. 2C may be produced by depositing a 3-4 ⁇ m PCLC layer and a 10-100 ⁇ m conductive layer onto a substrate by means described in Example 4. A final 2-3 ⁇ m layer of PCLC is deposited by procedures described in Examples 1 or 2 so that the composite flake resembles a sandwich, wherein a thin conductive layer is found between two PCLC layers.
- the flakes having the design shown in FIG. 2D are prepared in the same way as in Example 5 , except multiple layers that may be either conductive or dielectric are applied to produce a flake with three or more layers.
- the PCLC layers in Examples 1-6 may alternately be either polymer nematic liquid crystals or polymer smectic liquid crystals.
- the PCLC layers in Examples 1-6 may be an type of dielectric layer composed of a material or materials selected from a group of inorganic materials including but not limited to mica, titanium dioxide (rutile), aluminum oxide, silica, and magnesium fluoride or a group of organic polymers including but not limited to Mylar, cellophane, polyester, and polyethylene.
- a material or materials selected from a group of inorganic materials including but not limited to mica, titanium dioxide (rutile), aluminum oxide, silica, and magnesium fluoride or a group of organic polymers including but not limited to Mylar, cellophane, polyester, and polyethylene.
- the dielectric layers contained in Examples 1-6 and Example 8 are doped with a dye such as Oil Red-O to alter the optical properties of the dielectric layer. This construction is particularly suitable for obtaining color compensation effects as discussed above.
- the dielectric layers contained in Examples 1-6 and Example 8 are doped with nanoscale particles such as titania to alter the dielectric properties of the dielectric layer.
- Flakes having the design shown in FIG. 2A are processed to have a bottom layer that is a red colored dielectric (absorbs blue and green light, while reflecting red) and a top layer that is a PCLC with selective reflection in the red.
- the flake remains highly dielectric and must thus be suspended in a moderately conductive host fluid like propylene carbonate so that the flakes will reorient 90° when an AC electric field is applied.
- the flake brightly reflects red light.
- the selective reflection color from the top surface shifts from red to green.
- the green reflected light is mixed with the red light reflecting from the bottom layer, thereby producing an additive color of orange and mitigating the color shift that would normally be seen with red PCLC flakes.
- a highly dielectric host fluid such as silicone oil.
- Flakes having the design shown in FIG. 2C are processed to have a bottom layer that is a PCLC that reflects right-handed circularly polarized light and a bottom layer that is a PCLC that reflects left-handed circularly polarized light, with a conductive layer sandwiched between them.
- the resulting flakes are suspended in a highly dielectric host fluid such as silicone oil and can be reoriented using a DC electric field.
- the reflectivity of the device is nearly doubled because both right- and left-handed circularly polarized light is reflected.
Abstract
Description
- The present invention relates to optical devices having electrically addressable composite layered flakes with angularly dependent optical properties in a system including the flakes and a host fluid. The composite flakes have a plurality of layers of different materials, such as dielectric, conductive and polymer liquid crystalline materials. The optical properties are electrically selectable or addressable by an electric field applied toward the flake/host system.
- Reference may be made to the following patent documents which describe optical devices containing flake/host systems that rely on polymer liquid crystal (PLC) flakes to provide angularly dependent optical effects: U.S. patent application Ser. No. 09/571,805, filed May 16, 2002 and published in International Publication WO 01/88607, published Nov. 22, 2001; and U.S. patent application Ser. No. 10/405,163, filed Apr. 2, 2003 by Tanya Z. Kosc, Kenneth L. Marshall, and Stephen D. Jacobs. Both of these patent documents are incorporated herein by reference.
- Particles of various materials have been used, principally in devices relying on electrophoretic effects, in order to provide electrically switchable optical devices. These particles are generally all dielectric and do not rely on composite layers to obtain optical effects or to enhance particle motion as is the case with devices of the present invention. Reference may be made to the following U.S. Patents for further information regarding such prior devices: Labes, U.S. Pat. No. 4,657,349, issued Apr. 14, 1987; Albert, U.S. Pat. No. 6,392,785, issued May 21, 2002; Jacobson, U.S. Pat. No. 6,422,687, issued Jul. 23, 2002; Sheridon, U.S. Pat. No. 6,497,942, issued Dec. 24, 2002; and Albert, U.S. Pat. No. 6,515,649 issued Feb. 4, 2003. Other devices similar to those in the referenced patents, as well as other documents that describe them, are referenced in the above-identified International Publication.
- It has been discovered in accordance with the invention that composite or layered flakes that have heretofore been used exclusively as paint and ink pigments and have angularly dependent optical properties, can be selected or addressed by an electric field when contained in a flake/host system.
- The composite flakes used in a flake/host system in accordance with the invention may include both dielectric and conductive layers. The dielectric layers may include, but are not limited to, materials such as mica, titanium dioxide, rutile, aluminum oxide, silica, magnesium fluoride, polymers, Mylar (polytetrafluorethylene), cellophane, polyester, and polyethylene and polymer liquid crystals (PLC's). Metals such as gold, silver, aluminum, tin, and metal oxides such as tin oxide or indium tin oxide may be used as the conductive layer, but the conductive layer is not limited to these materials.
- The angularly dependent optical properties may be obtained in several ways: (1) one or more of the layers can be liquid crystalline; (2) two or more layers can reflect light, causing optical interference effects as determined by the index of refraction and the thickness of the layers; (3) one or more layers can contain holograms; (4) any combination of these methods can be used.
- Though angularly dependent optical effects are often desired, there are conditions in which it is preferable to suppress or alter the angular dependence. This suppression of angular dependence can be achieved by preparing composite flakes with a specifically colored layer, such as a dyed polymer, coated with a layer having angularly dependent optical properties, such as a liquid crystal, and utilizing additive and/or subtractive color effects. The composite flake reflects a specific color when it is illuminated and viewed normally. However when the composite flake is viewed off-axis, the constant color reflecting from the bottom layer compensates for the shifting color being reflected from the top liquid crystalline layer, minimizing the change/shift in apparent color. A specifically colored bottom layer in a composite flake is not limited to suppression of angle-dependent color effects. Specific color combinations can also alter, intensify, and enhance color dependent effects.
- A composite flake may also serve to manipulate the effects of circular polarization that are obtained when polymer cholesteric liquid crystal (PCLC) layers are used. PCLC's have an inherent optical property known as selective reflection that causes a PCLC layer to reflect only light of a specific wavelength (color) and circular polarization (right- or left-handed). The ability to provide polarized light is highly desirable for many applications, particularly those employing three-dimensional effects or tagging for security features. Because selective reflection only reflects one handedness of light, the opposite handedness, or 50% of the light, is not utilized. In applications where brightness of the reflecting layer is a primary concern, it would be useful to manufacture composite flakes possessing two layers of PCLC, with each layer reflecting one of the two polarizations of light, thus maximizing flake reflectivity.
- The use of a metallic layer may be two fold. In certain inks and pigments, the metallic layer is required to produce the desired optical effect, particularly for “pearl luster” or “pearlescent” pigments. When a metallic layer is included in the stack (composition) of layers in a composite flake, it will change the dielectric properties of the flakes. Since the metallic layer is conductive, it significantly alters flake behavior when an electric field is applied.
- The plurality of layers in composite flakes can be dielectric and can be composed of two or more layers. For example, dielectric layers can be used to “sandwich” a metal oxide layer or a metal layer. One or more of those dielectric layers may be a PLC (either a PCLC, a polymer nematic liquid crystal, or a polymer smectic liquid crystal). The flakes may be produced by the methods described in the examples that appear below.
- Various commercial pigments may be used to provide the composite flakes. Some of such pigments and their manufacturers are listed in the following table. In the table, “pearl luster” thin film pigments are the traditional pigments based on mica platelets coated with aluminium or bronze layers whose thickness determines the color of the interference effect. “Multiple layer” thin film pigments refer to pigments that use multiple layers (typically dielectric) for interference effects.
Manufacturer Flake/pigment/ink Eckart Stapa metallic pigment Silberline Silvet, Sivex metallic pigment Engelhard Mearlin, Bi-Lite, Chroma-Lite, thin film “pearl luster” pigment Cellini, organic thin film “pearl luster” pigemtn Merck Iriodin, Bi-flair, “pearl luster” thin film pigment Xiralic coated aluminum oxide pigment Colorstream transparent silica pigment Flex Products Inc. Chrooaflair “multiple layer” thin pigment layer BASF AG Paliogcrom, “pearl luster” thin film pig- ment Variochrom “multiple layer” thin film pigment, holographic pigments (to be introduced) PPG Industries Geometric Pigments ™ holographic pigments Wacker-Chemie AG Helicone liquid crystal pigments Eckhart-Werke Alucolor, Aloxal aluminum coated with color pigments and coated with SiO2 Toyo Aluminum with Nissin Metashine, CrystalStar metallized Steel Coi., Ltd. & Nippon glass flakes Sheet Glass Co., Ltd. - In addition, the following United States Patents describe composites of layered flakes for pigments used in paint and ink: Venis, U.S. Pat. No. 4,168,986, issued Sep. 25, 1979; Phillips et al., U.S. Pat. No. 5,279,657, issued Jan. 18, 1994, Phillips et al., U.S. Pat. No. 5,571,624, Issued Nov. 5, 1996; Hou et al., U.S. Pat. No. 5,587,242, issued Dec. 24, 1996; Miekka et al., U.S. Pat. No. 5,672,410, issued Sep. 30, 1997; Phillips et al., U.S. Pat. No. 5,766,738, issued Jun. 16, 1998. Pigments using PCLC and other layers appear in Muller-Rees et al., U.S. Pat. No. 5,851,604, issued Dec. 22, 1998; Poetsch et al., U.S. Pat. No. 6,291,065, issued Sep. 18, 2001; U.S. Patent Application Publication, Inoue et al., U.S. 2002/0033117, published, Mar. 21, 2002. The foregoing patents also describe methods of making the composite layered flakes.
- The foregoing and other features and advantages of the invention will become more apparent from the following description and the accompanying drawing in which:
- FIG. 1A is a perspective view of a typical irregularly shaped flake which is usable in a flake/host system of an optical device provided by the invention, particularly in a cell containing the system as shown in FIGS. 1B and 1C;
- FIG. 1B is a schematic diagram of a cell incorporating the flake/host system wherein the flakes lie approximately parallel to the cell substrates or walls as occurs when no electric field is applied;
- FIG. 1C is a view similar to FIG. 1B that shows the flakes reoriented with their long axis parallel to a field that is applied perpendicular to the substrates;
- FIG. 2A-2D are sectional views showing composite flakes having different arrangements of layers of different types and materials, the views being taken along the line2-2 in FIG. 1A;
- Referring to FIGS. 1A-1C, the
basic device 10 embodying the invention represents a cell having a suspension ofPCLC flake 12 inhost fluid 14, which provides a flake/host system. Specific examples of such a host fluid that is used when conductivity is desired are propylene carbonate or poly(ethylene glycol). Silicone oils provide an essential nonconductive host fluid. - A typical device is constructed using an indium tin oxide (ITO) coated glass substrate16 (in contact with the suspension), though a flexible polymer substrate can also be used. Uniform cell gaps between the
substrates 16 may be set by spacers (e.g. beads, fibers, or gaskets), and thedevice 10 may be filled with the flake/host fluid suspension 14 using capillary action. Thedevice 10 may be driven with either a DC or an AC electric field, whereby any periodic waveform can be used as an AC driving field. Waveform bursts or DC spikes may be used prior to or following the main driving waveform to help control or alter flake behavior. The details of device construction were already disclosed in the above-referenced U.S. Patent Applications and International Publication. - PCLC
flakes 12 in the flake/host fluid system respond to electric fields by rotating about one axis, most commonly that which is parallel to the longest flake dimension. Atypical flake 12 is shown in FIG. 1A. Flakes lying in the plane defined by the substrate reflect brightly (FIG 1B), but once they reorient perpendicular to the substrate, little light is reflected (FIG 1C). - The preferred host fluid in cases where the flakes are highly dielectric (not conductive) is a moderately conductive host fluid such as propylene carbonate or poly(ethylene glycol). When the flakes contain a conductive layer, then a highly insulating host fluid such as silicone oil is preferred. Reference may be made to the following examples for making different flake designs:
- A flake having a two layer cross-section shown in FIG. 2A may include a polymer liquid crystal (PLC) thin film deposited onto a silicon substrate via knife coating, spin coating, dip coating or other coating technologies known to those skilled in the art. A dielectric layer is deposited onto the existing PLC layer so that the thickness of both layers totals 5-7 μm.
- For depositing dielectric layers on the order of nanometers, techniques such as electron beam deposition, chemical vapor deposition, sputter-coating, or dip-coating may be used. For depositing dielectric layers on the order of micrometers, techniques such as dip-coating, knife-coating or spin-coating may be used. Dielectric layers in both cases may be deposited using other additional techniques know to those skilled in the art.
- The dielectric layer is composed of a material or materials selected from a group of inorganic materials including but not limited to mica, titanium dioxide (rutile), aluminum oxide, silica, and magnesium fluoride or a group of organic polymers including but not limited to Mylar, cellophane, polyester, and polyethylene.
- Liquid nitrogen is poured over the composite film, and the film fractures due to the large difference in the thermal expansion coefficients of the silicon wafer and the PLC film. The flakes are collected by rinsing them off of the substrates and into a storage container with a chemically compatible solvent such as methanol, which can be either evaporated or retained for storage.
- A flake having the two-layer design shown in FIG. 2A with a total thickness of 5-7 μm may be created using patterning techniques such as the flexible mold substrate described in U.S. patent application Ser. No. 10/383,603, filed Mar. 7, 2003, by Anka Trajkovska-Petkoska et al. The PLC material and the mold substrate are heated to a temperature at which the PLC material is soft and sufficiently fluid to be pushed into the wells. Alternatively the PLC can be dissolved in a solvent such as methylene chloride or toluene and poured into the wells, and further processing is continued once the solvent has evaporated.
- A dielectric layer on the order of tens or hundreds of nanometers thick composed of a material or materials selected from a group of inorganic or a group of organic polymers is deposited onto the existing PLC layer as described in Example 1. Alternately, a dielectric layer on the order of micrometers is deposited into the wells and onto the existing PLC layer in a similar manner that the PLC layer is deposited.
- The flakes are released by flexing the mold substrate so that each flake falls out of its well and into a collection container. Loose flakes may also be washed off a substrate with a chemically compatible solvent and stored for further use.
- Flakes having the design shown in FIG. 2A may be produced by depositing a 3-5 μm thin PLC layer onto an existing dielectric layer consisting of a material selected from a group of inorganic materials including but not limited to mica, titanium dioxide (rutile), aluminum oxide, silica, and magnesium fluoride or a group of organic polymers including but not limited to Mylar, cellophane, polyester, and polyethylene. The dielectric layer can be deposited onto a pre-existing substrate such as a silicon wafer, or it can be deposited into wells for a mold substrate. The product flakes after forming are collected as described in previous Examples 1 and 2.
- Flakes having the design shown in FIG. 2B may be produced by depositing a 5-7 μm PCLC layer onto a silicone substrate as described in Example 1 or the PLC is deposited into wells of a mold substrate as described in Example 2. A conductive layer (gold, silver, aluminum, tin, etc) on the order of tens or hundreds of Angstroms is deposited onto the existing PLC layer using techniques such as electron beam deposition, chemical vapor deposition, sputter-coating, or additional coating techniques known to those skilled in the art. The flakes are produced, or released as described in Examples 1 and 2 respectively.
- Flakes having the design shown in FIG. 2C may be produced by depositing a 3-4 μm PCLC layer and a 10-100 μm conductive layer onto a substrate by means described in Example 4. A final 2-3 μm layer of PCLC is deposited by procedures described in Examples 1 or 2 so that the composite flake resembles a sandwich, wherein a thin conductive layer is found between two PCLC layers.
- The flakes having the design shown in FIG. 2D are prepared in the same way as in Example5, except multiple layers that may be either conductive or dielectric are applied to produce a flake with three or more layers.
- The PCLC layers in Examples 1-6 may alternately be either polymer nematic liquid crystals or polymer smectic liquid crystals.
- The PCLC layers in Examples 1-6 may be an type of dielectric layer composed of a material or materials selected from a group of inorganic materials including but not limited to mica, titanium dioxide (rutile), aluminum oxide, silica, and magnesium fluoride or a group of organic polymers including but not limited to Mylar, cellophane, polyester, and polyethylene.
- The dielectric layers contained in Examples 1-6 and Example 8 are doped with a dye such as Oil Red-O to alter the optical properties of the dielectric layer. This construction is particularly suitable for obtaining color compensation effects as discussed above.
- The dielectric layers contained in Examples 1-6 and Example 8 are doped with nanoscale particles such as titania to alter the dielectric properties of the dielectric layer.
- Flakes having the design shown in FIG. 2A are processed to have a bottom layer that is a red colored dielectric (absorbs blue and green light, while reflecting red) and a top layer that is a PCLC with selective reflection in the red. The flake remains highly dielectric and must thus be suspended in a moderately conductive host fluid like propylene carbonate so that the flakes will reorient 90° when an AC electric field is applied. In the initial “off” state, the flake brightly reflects red light. Once the electric field is applied and the flake starts to reorient, the selective reflection color from the top surface shifts from red to green. The green reflected light is mixed with the red light reflecting from the bottom layer, thereby producing an additive color of orange and mitigating the color shift that would normally be seen with red PCLC flakes.
- Flakes having the design shown in FIG. 2D or flakes such as the Chroma-lite pigments produced by Engelhard Corp., which have dielectric thin film layers and at least one conductive layer, are suspended in a highly dielectric host fluid such as silicone oil. A DC electric field is applied, causing the flakes to reorient 90° and a color shift in the reflected light.
- Flakes having the design shown in FIG. 2C are processed to have a bottom layer that is a PCLC that reflects right-handed circularly polarized light and a bottom layer that is a PCLC that reflects left-handed circularly polarized light, with a conductive layer sandwiched between them. The resulting flakes are suspended in a highly dielectric host fluid such as silicone oil and can be reoriented using a DC electric field. The reflectivity of the device is nearly doubled because both right- and left-handed circularly polarized light is reflected.
- From the foregoing description, it will be apparent that there has been provided dielectric devices which have features in addition to those of the above referenced applications. Variations and modifications in the described devices, within the scope of the invention will undoubtedly become apparent to those skilled in the art. The foregoing description should be taken as illustrative and not limiting, and Examples 11-13 provide a few possible ways to utilize composite flakes suspended in a host fluid and driven by an electric field.
Claims (15)
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/441,453 US6829075B1 (en) | 2003-05-20 | 2003-05-20 | Electrically addressable optical devices using a system of composite layered flakes suspended in a fluid host to obtain angularly dependent optical effects |
PCT/US2004/015618 WO2004104685A1 (en) | 2003-05-20 | 2004-05-19 | Electrically addressable optical devices using a system of composite layered flakes suspended in a fluid host to obtain angularly dependent optical effects |
EP04752610A EP1636643A1 (en) | 2003-05-20 | 2004-05-19 | Electrically addressable optical devices using a system of composite layered flakes suspended in a fluid host to obtain angularly dependent optical effects |
TW093114273A TW200510889A (en) | 2003-05-20 | 2004-05-20 | Electrically addressable optical devices using a system of composite layered flakes suspended in a fluid host to obtain angularly dependent optical effects |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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US10/441,453 US6829075B1 (en) | 2003-05-20 | 2003-05-20 | Electrically addressable optical devices using a system of composite layered flakes suspended in a fluid host to obtain angularly dependent optical effects |
Publications (2)
Publication Number | Publication Date |
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US20040233508A1 true US20040233508A1 (en) | 2004-11-25 |
US6829075B1 US6829075B1 (en) | 2004-12-07 |
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US10/441,453 Expired - Lifetime US6829075B1 (en) | 2003-05-20 | 2003-05-20 | Electrically addressable optical devices using a system of composite layered flakes suspended in a fluid host to obtain angularly dependent optical effects |
Country Status (4)
Country | Link |
---|---|
US (1) | US6829075B1 (en) |
EP (1) | EP1636643A1 (en) |
TW (1) | TW200510889A (en) |
WO (1) | WO2004104685A1 (en) |
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WO2007094778A2 (en) | 2005-02-22 | 2007-08-23 | United Defense, Lp | Reflective electroactive particles |
US20120019738A1 (en) * | 2010-07-21 | 2012-01-26 | University Of Rochester | Pclc flake-based apparatus and method |
WO2014002788A1 (en) * | 2012-06-27 | 2014-01-03 | シャープ株式会社 | Display panel and display device |
US8864037B2 (en) | 2012-03-27 | 2014-10-21 | Sicpa Holding Sa | Multilayer flake with high level of coding |
WO2015191084A1 (en) * | 2014-06-13 | 2015-12-17 | Halliburton Energy Services, Inc. | Integrated computational element with multiple frequency selective surfaces |
CN108153032A (en) * | 2018-02-06 | 2018-06-12 | 深圳晶奕科技有限公司 | A kind of nano microcrystalline coating intelligent dimming high definition image film |
US10247662B2 (en) | 2013-07-09 | 2019-04-02 | Halliburton Energy Services, Inc. | Integrated computational elements with frequency selective surface |
US10718881B2 (en) | 2013-07-09 | 2020-07-21 | Halliburton Energy Services, Inc. | Integrated computational elements with laterally-distributed spectral filters |
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AU2002304051B2 (en) * | 2001-04-24 | 2007-08-16 | Merck Patent Gmbh | Birefringent Marking |
US7713436B1 (en) | 2005-09-19 | 2010-05-11 | The University Of Rochester | Electrically actuatable doped polymer flakes and electrically addressable optical devices using suspensions of doped polymer flakes in a fluid host |
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US10197856B2 (en) | 2015-04-03 | 2019-02-05 | Sharp Kabushiki Kaisha | Optical modulator and display device |
Citations (59)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3406363A (en) * | 1966-05-26 | 1968-10-15 | Clarence R. Tate | Multicolored micromagnets |
US3668106A (en) * | 1970-04-09 | 1972-06-06 | Matsushita Electric Ind Co Ltd | Electrophoretic display device |
US3841732A (en) * | 1970-03-04 | 1974-10-15 | A Marks | Dipolar electro-optic structures and method |
US3967265A (en) * | 1971-08-03 | 1976-06-29 | Jacob Carlyle W | Light gating display |
US4076387A (en) * | 1976-07-02 | 1978-02-28 | Xerox Corporation | Magnetic display |
US4126854A (en) * | 1976-05-05 | 1978-11-21 | Xerox Corporation | Twisting ball panel display |
US4126528A (en) * | 1977-07-26 | 1978-11-21 | Xerox Corporation | Electrophoretic composition and display device |
US4143103A (en) * | 1976-05-04 | 1979-03-06 | Xerox Corporation | Method of making a twisting ball panel display |
US4168986A (en) * | 1978-07-03 | 1979-09-25 | Polaroid Corporation | Method for preparing lamellar pigments |
US4270841A (en) * | 1978-10-31 | 1981-06-02 | Research Frontiers Incorporated | Light valve containing suspension of perhalide of alkaloid acid salt |
US4285801A (en) * | 1979-09-20 | 1981-08-25 | Xerox Corporation | Electrophoretic display composition |
US4298448A (en) * | 1979-02-02 | 1981-11-03 | Bbc Brown, Boveri & Company, Limited | Electrophoretic display |
US4305807A (en) * | 1980-03-13 | 1981-12-15 | Burroughs Corporation | Electrophoretic display device using a liquid crystal as a threshold device |
US4311361A (en) * | 1980-03-13 | 1982-01-19 | Burroughs Corporation | Electrophoretic display using a non-Newtonian fluid as a threshold device |
US4657349A (en) * | 1984-08-14 | 1987-04-14 | Temple University | Electro- and magneto-optic devices |
US4680103A (en) * | 1986-01-24 | 1987-07-14 | Epid. Inc. | Positive particles in electrophoretic display device composition |
US4688900A (en) * | 1984-03-19 | 1987-08-25 | Kent State University | Light modulating material comprising a liquid crystal dispersion in a plastic matrix |
US4707080A (en) * | 1981-09-16 | 1987-11-17 | Manchester R & D Partnership | Encapsulated liquid crystal material, apparatus and method |
US4919521A (en) * | 1987-06-03 | 1990-04-24 | Nippon Sheet Glass Co., Ltd. | Electromagnetic device |
US5059245A (en) * | 1979-12-28 | 1991-10-22 | Flex Products, Inc. | Ink incorporating optically variable thin film flakes |
US5279657A (en) * | 1979-12-28 | 1994-01-18 | Flex Products, Inc. | Optically variable printing ink |
US5344594A (en) * | 1991-10-29 | 1994-09-06 | Xerox Corporation | Method for the fabrication of multicolored balls for a twisting ball display |
US5364557A (en) * | 1991-11-27 | 1994-11-15 | Faris Sades M | Aligned cholesteric liquid crystal inks |
US5380362A (en) * | 1993-07-16 | 1995-01-10 | Copytele, Inc. | Suspension for use in electrophoretic image display systems |
US5389945A (en) * | 1989-11-08 | 1995-02-14 | Xerox Corporation | Writing system including paper-like digitally addressed media and addressing device therefor |
US5523863A (en) * | 1988-10-19 | 1996-06-04 | Fergason; James L. | Controlled liquid crystal optical polarizer method and apparatus |
US5571624A (en) * | 1979-12-28 | 1996-11-05 | Flex Products, Inc. | High chroma multilayer interference platelets |
US5587242A (en) * | 1993-05-21 | 1996-12-24 | Copytele, Inc. | Colored polymeric dielectric particles and method of manufacture |
US5650872A (en) * | 1994-12-08 | 1997-07-22 | Research Frontiers Incorporated | Light valve containing ultrafine particles |
US5672410A (en) * | 1992-05-11 | 1997-09-30 | Avery Dennison Corporation | Embossed metallic leafing pigments |
US5691795A (en) * | 1991-05-02 | 1997-11-25 | Kent State University | Polymer stabilized liquid crystalline light modulating device and material |
US5691789A (en) * | 1995-10-30 | 1997-11-25 | Li; Le | Single-layer reflective super broadband circular polarizer and method of fabrication therefor |
US5708525A (en) * | 1995-12-15 | 1998-01-13 | Xerox Corporation | Applications of a transmissive twisting ball display |
US5717514A (en) * | 1995-12-15 | 1998-02-10 | Xerox Corporation | Polychromal segmented balls for a twisting ball display |
US5717283A (en) * | 1996-01-03 | 1998-02-10 | Xerox Corporation | Display sheet with a plurality of hourglass shaped capsules containing marking means responsive to external fields |
US5737115A (en) * | 1995-12-15 | 1998-04-07 | Xerox Corporation | Additive color tristate light valve twisting ball display |
US5739801A (en) * | 1995-12-15 | 1998-04-14 | Xerox Corporation | Multithreshold addressing of a twisting ball display |
US5751268A (en) * | 1995-12-15 | 1998-05-12 | Xerox Corporation | Pseudo-four color twisting ball display |
US5754332A (en) * | 1996-06-27 | 1998-05-19 | Xerox Corporation | Monolayer gyricon display |
US5760761A (en) * | 1995-12-15 | 1998-06-02 | Xerox Corporation | Highlight color twisting ball display |
US5767826A (en) * | 1995-12-15 | 1998-06-16 | Xerox Corporation | Subtractive color twisting ball display |
US5766738A (en) * | 1979-12-28 | 1998-06-16 | Flex Products, Inc. | Paired optically variable article with paired optically variable structures and ink, paint and foil incorporating the same and method |
US5825529A (en) * | 1996-06-27 | 1998-10-20 | Xerox Corporation | Gyricon display with no elastomer substrate |
US5851604A (en) * | 1994-05-06 | 1998-12-22 | Consortium Fur Elektrochemische Industrie Gmbh | Interference pigments comprising molecules fixed in a cholesteric configuration, and use thereof |
US5940150A (en) * | 1991-11-27 | 1999-08-17 | Reveo, Inc. | Electro-optical glazing structures having total-reflection and transparent modes of operation for use in dynamical control of electromagnetic radiation |
US5961804A (en) * | 1997-03-18 | 1999-10-05 | Massachusetts Institute Of Technology | Microencapsulated electrophoretic display |
US6017584A (en) * | 1995-07-20 | 2000-01-25 | E Ink Corporation | Multi-color electrophoretic displays and materials for making the same |
US6034753A (en) * | 1991-11-27 | 2000-03-07 | Reveo, Inc. | Circularly polarizing reflective material having super broad-band reflection and transmission characteristics and method of fabricating and using same in diverse applications |
US6133980A (en) * | 1995-10-30 | 2000-10-17 | Metrologic Instruments, Inc. | Liquid crystal film structures with phase-retardation surface regions formed therein and methods of fabricating the same |
US6291065B1 (en) * | 1997-03-21 | 2001-09-18 | Merck Patent Gmbh | Pigment flakes |
US20020033117A1 (en) * | 2000-04-13 | 2002-03-21 | Sakura Color Products Corporation | Polychromic ink composition depending on viewing angle |
US6392785B1 (en) * | 1997-08-28 | 2002-05-21 | E Ink Corporation | Non-spherical cavity electrophoretic displays and materials for making the same |
US6394595B1 (en) * | 1998-08-28 | 2002-05-28 | Reveo, Inc. | Apparatus for producing multi-color images on substrates using dry multi-colored cholesteric liquid crystal (CLC) pigment materials |
US6422687B1 (en) * | 1996-07-19 | 2002-07-23 | E Ink Corporation | Electronically addressable microencapsulated ink and display thereof |
US6445490B1 (en) * | 2000-11-28 | 2002-09-03 | Xerox Corporation | Encapsulated gyricon spheres |
US6497942B2 (en) * | 1996-06-27 | 2002-12-24 | Xerox Corporation | Twisting-cylinder display |
US6498674B1 (en) * | 2000-04-14 | 2002-12-24 | Xerox Corporation | Rotating element sheet material with generalized containment structure |
US6515649B1 (en) * | 1995-07-20 | 2003-02-04 | E Ink Corporation | Suspended particle displays and materials for making the same |
US6665042B1 (en) * | 2000-05-16 | 2003-12-16 | The University Of Rochester | Electrically switchable polymer liquid crystal and polymer birefringent flake in fluid host systems and optical devices utilizing same |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2276883A (en) | 1993-04-05 | 1994-10-12 | Central Research Lab Ltd | Optical material containing a liquid crystal |
-
2003
- 2003-05-20 US US10/441,453 patent/US6829075B1/en not_active Expired - Lifetime
-
2004
- 2004-05-19 EP EP04752610A patent/EP1636643A1/en not_active Withdrawn
- 2004-05-19 WO PCT/US2004/015618 patent/WO2004104685A1/en active Application Filing
- 2004-05-20 TW TW093114273A patent/TW200510889A/en unknown
Patent Citations (59)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3406363A (en) * | 1966-05-26 | 1968-10-15 | Clarence R. Tate | Multicolored micromagnets |
US3841732A (en) * | 1970-03-04 | 1974-10-15 | A Marks | Dipolar electro-optic structures and method |
US3668106A (en) * | 1970-04-09 | 1972-06-06 | Matsushita Electric Ind Co Ltd | Electrophoretic display device |
US3967265A (en) * | 1971-08-03 | 1976-06-29 | Jacob Carlyle W | Light gating display |
US4143103A (en) * | 1976-05-04 | 1979-03-06 | Xerox Corporation | Method of making a twisting ball panel display |
US4126854A (en) * | 1976-05-05 | 1978-11-21 | Xerox Corporation | Twisting ball panel display |
US4076387A (en) * | 1976-07-02 | 1978-02-28 | Xerox Corporation | Magnetic display |
US4126528A (en) * | 1977-07-26 | 1978-11-21 | Xerox Corporation | Electrophoretic composition and display device |
US4168986A (en) * | 1978-07-03 | 1979-09-25 | Polaroid Corporation | Method for preparing lamellar pigments |
US4270841A (en) * | 1978-10-31 | 1981-06-02 | Research Frontiers Incorporated | Light valve containing suspension of perhalide of alkaloid acid salt |
US4298448A (en) * | 1979-02-02 | 1981-11-03 | Bbc Brown, Boveri & Company, Limited | Electrophoretic display |
US4285801A (en) * | 1979-09-20 | 1981-08-25 | Xerox Corporation | Electrophoretic display composition |
US5766738A (en) * | 1979-12-28 | 1998-06-16 | Flex Products, Inc. | Paired optically variable article with paired optically variable structures and ink, paint and foil incorporating the same and method |
US5279657A (en) * | 1979-12-28 | 1994-01-18 | Flex Products, Inc. | Optically variable printing ink |
US5571624A (en) * | 1979-12-28 | 1996-11-05 | Flex Products, Inc. | High chroma multilayer interference platelets |
US5059245A (en) * | 1979-12-28 | 1991-10-22 | Flex Products, Inc. | Ink incorporating optically variable thin film flakes |
US4305807A (en) * | 1980-03-13 | 1981-12-15 | Burroughs Corporation | Electrophoretic display device using a liquid crystal as a threshold device |
US4311361A (en) * | 1980-03-13 | 1982-01-19 | Burroughs Corporation | Electrophoretic display using a non-Newtonian fluid as a threshold device |
US4707080A (en) * | 1981-09-16 | 1987-11-17 | Manchester R & D Partnership | Encapsulated liquid crystal material, apparatus and method |
US4688900A (en) * | 1984-03-19 | 1987-08-25 | Kent State University | Light modulating material comprising a liquid crystal dispersion in a plastic matrix |
US4657349A (en) * | 1984-08-14 | 1987-04-14 | Temple University | Electro- and magneto-optic devices |
US4680103A (en) * | 1986-01-24 | 1987-07-14 | Epid. Inc. | Positive particles in electrophoretic display device composition |
US4919521A (en) * | 1987-06-03 | 1990-04-24 | Nippon Sheet Glass Co., Ltd. | Electromagnetic device |
US5523863A (en) * | 1988-10-19 | 1996-06-04 | Fergason; James L. | Controlled liquid crystal optical polarizer method and apparatus |
US5389945A (en) * | 1989-11-08 | 1995-02-14 | Xerox Corporation | Writing system including paper-like digitally addressed media and addressing device therefor |
US5691795A (en) * | 1991-05-02 | 1997-11-25 | Kent State University | Polymer stabilized liquid crystalline light modulating device and material |
US5344594A (en) * | 1991-10-29 | 1994-09-06 | Xerox Corporation | Method for the fabrication of multicolored balls for a twisting ball display |
US5364557A (en) * | 1991-11-27 | 1994-11-15 | Faris Sades M | Aligned cholesteric liquid crystal inks |
US6034753A (en) * | 1991-11-27 | 2000-03-07 | Reveo, Inc. | Circularly polarizing reflective material having super broad-band reflection and transmission characteristics and method of fabricating and using same in diverse applications |
US5940150A (en) * | 1991-11-27 | 1999-08-17 | Reveo, Inc. | Electro-optical glazing structures having total-reflection and transparent modes of operation for use in dynamical control of electromagnetic radiation |
US5672410A (en) * | 1992-05-11 | 1997-09-30 | Avery Dennison Corporation | Embossed metallic leafing pigments |
US5587242A (en) * | 1993-05-21 | 1996-12-24 | Copytele, Inc. | Colored polymeric dielectric particles and method of manufacture |
US5380362A (en) * | 1993-07-16 | 1995-01-10 | Copytele, Inc. | Suspension for use in electrophoretic image display systems |
US5851604A (en) * | 1994-05-06 | 1998-12-22 | Consortium Fur Elektrochemische Industrie Gmbh | Interference pigments comprising molecules fixed in a cholesteric configuration, and use thereof |
US5650872A (en) * | 1994-12-08 | 1997-07-22 | Research Frontiers Incorporated | Light valve containing ultrafine particles |
US6017584A (en) * | 1995-07-20 | 2000-01-25 | E Ink Corporation | Multi-color electrophoretic displays and materials for making the same |
US6515649B1 (en) * | 1995-07-20 | 2003-02-04 | E Ink Corporation | Suspended particle displays and materials for making the same |
US5691789A (en) * | 1995-10-30 | 1997-11-25 | Li; Le | Single-layer reflective super broadband circular polarizer and method of fabrication therefor |
US6133980A (en) * | 1995-10-30 | 2000-10-17 | Metrologic Instruments, Inc. | Liquid crystal film structures with phase-retardation surface regions formed therein and methods of fabricating the same |
US5737115A (en) * | 1995-12-15 | 1998-04-07 | Xerox Corporation | Additive color tristate light valve twisting ball display |
US5767826A (en) * | 1995-12-15 | 1998-06-16 | Xerox Corporation | Subtractive color twisting ball display |
US5760761A (en) * | 1995-12-15 | 1998-06-02 | Xerox Corporation | Highlight color twisting ball display |
US5708525A (en) * | 1995-12-15 | 1998-01-13 | Xerox Corporation | Applications of a transmissive twisting ball display |
US5751268A (en) * | 1995-12-15 | 1998-05-12 | Xerox Corporation | Pseudo-four color twisting ball display |
US5739801A (en) * | 1995-12-15 | 1998-04-14 | Xerox Corporation | Multithreshold addressing of a twisting ball display |
US5717514A (en) * | 1995-12-15 | 1998-02-10 | Xerox Corporation | Polychromal segmented balls for a twisting ball display |
US5717283A (en) * | 1996-01-03 | 1998-02-10 | Xerox Corporation | Display sheet with a plurality of hourglass shaped capsules containing marking means responsive to external fields |
US5754332A (en) * | 1996-06-27 | 1998-05-19 | Xerox Corporation | Monolayer gyricon display |
US6497942B2 (en) * | 1996-06-27 | 2002-12-24 | Xerox Corporation | Twisting-cylinder display |
US5825529A (en) * | 1996-06-27 | 1998-10-20 | Xerox Corporation | Gyricon display with no elastomer substrate |
US6422687B1 (en) * | 1996-07-19 | 2002-07-23 | E Ink Corporation | Electronically addressable microencapsulated ink and display thereof |
US5961804A (en) * | 1997-03-18 | 1999-10-05 | Massachusetts Institute Of Technology | Microencapsulated electrophoretic display |
US6291065B1 (en) * | 1997-03-21 | 2001-09-18 | Merck Patent Gmbh | Pigment flakes |
US6392785B1 (en) * | 1997-08-28 | 2002-05-21 | E Ink Corporation | Non-spherical cavity electrophoretic displays and materials for making the same |
US6394595B1 (en) * | 1998-08-28 | 2002-05-28 | Reveo, Inc. | Apparatus for producing multi-color images on substrates using dry multi-colored cholesteric liquid crystal (CLC) pigment materials |
US20020033117A1 (en) * | 2000-04-13 | 2002-03-21 | Sakura Color Products Corporation | Polychromic ink composition depending on viewing angle |
US6498674B1 (en) * | 2000-04-14 | 2002-12-24 | Xerox Corporation | Rotating element sheet material with generalized containment structure |
US6665042B1 (en) * | 2000-05-16 | 2003-12-16 | The University Of Rochester | Electrically switchable polymer liquid crystal and polymer birefringent flake in fluid host systems and optical devices utilizing same |
US6445490B1 (en) * | 2000-11-28 | 2002-09-03 | Xerox Corporation | Encapsulated gyricon spheres |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2007094778A2 (en) | 2005-02-22 | 2007-08-23 | United Defense, Lp | Reflective electroactive particles |
EP1888328A2 (en) * | 2005-02-22 | 2008-02-20 | BAE Systems Land & Armaments L.P. | Reflective electroactive particles |
EP1888328A4 (en) * | 2005-02-22 | 2009-10-21 | Bae Sys Land & Armaments Lp | Reflective electroactive particles |
US20120019738A1 (en) * | 2010-07-21 | 2012-01-26 | University Of Rochester | Pclc flake-based apparatus and method |
US8293135B2 (en) * | 2010-07-21 | 2012-10-23 | University Of Rochester | PCLC flake-based apparatus and method |
US8864037B2 (en) | 2012-03-27 | 2014-10-21 | Sicpa Holding Sa | Multilayer flake with high level of coding |
WO2014002788A1 (en) * | 2012-06-27 | 2014-01-03 | シャープ株式会社 | Display panel and display device |
US9519176B2 (en) | 2012-06-27 | 2016-12-13 | Sharp Kabushiki Kaisha | Display panel and display device |
US10247662B2 (en) | 2013-07-09 | 2019-04-02 | Halliburton Energy Services, Inc. | Integrated computational elements with frequency selective surface |
US10718881B2 (en) | 2013-07-09 | 2020-07-21 | Halliburton Energy Services, Inc. | Integrated computational elements with laterally-distributed spectral filters |
WO2015191084A1 (en) * | 2014-06-13 | 2015-12-17 | Halliburton Energy Services, Inc. | Integrated computational element with multiple frequency selective surfaces |
US9708908B2 (en) | 2014-06-13 | 2017-07-18 | Halliburton Energy Services, Inc. | Integrated computational element with multiple frequency selective surfaces |
CN108153032A (en) * | 2018-02-06 | 2018-06-12 | 深圳晶奕科技有限公司 | A kind of nano microcrystalline coating intelligent dimming high definition image film |
Also Published As
Publication number | Publication date |
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US6829075B1 (en) | 2004-12-07 |
TW200510889A (en) | 2005-03-16 |
EP1636643A1 (en) | 2006-03-22 |
WO2004104685A1 (en) | 2004-12-02 |
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