Reflective displays typically suffer from low brightness. A novel retroreflector formed of a linear prismatic structure with an array of total internal reflection-based hierarchical microstructures and an opposing specular reflective surface may have potential to replace conventional retroreflectors. Nearly all of the incident light is retroreflected back towards the viewer leading to a brighter display. The novel retroreflectors described herein may be used in static display signage and electronically switchable displays.
G02B 5/124 - Reflex reflectors cube corner, trihedral or triple reflector type plural reflecting elements forming part of a unitary plate or sheet
G02B 26/08 - Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
G02B 27/09 - Beam shaping, e.g. changing the cross-sectioned area, not otherwise provided for
G02F 1/1335 - Structural association of cells with optical devices, e.g. polarisers or reflectors
Color may be achieved in TIR-based image displays by addition of a sub-pixel color filter array (CFA). Color may be enhanced by tuning the size, shape, arrangement and colors of the sub-pixel color filters in the CFA. CFAs comprising of pixels further comprising one to four or more different repeating sub-pixel color filters may be capable of creating a wide gamut of displayable colors. The sub-pixels may be arranged in repeat cells wherein the sub-pixels within the repeat cell may be mapped to one or more pixels. Sub-pixel rendering may be used during driving of a TIR-based display. Sub-pixel rendering uses logical dynamic pixels where a single sub-pixel may be used in one or more pixels depending on the image displayed.
G02F 1/167 - 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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
G09G 3/34 - Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix by control of light from an independent source
Electrophoretic displays that are capable of operating at low voltages to move electrophoretically mobile particles may be driven by a low power apparatus. The apparatus may comprise Memory-In-Chip (MIP) technology to enhance or create image stability. MIP may comprise a 1-bit memory SRAM or DRAM circuit located in one or more pixels in a TFT array backplane.
G02F 1/167 - 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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
4.
APPARATUS AND METHOD FOR REFLECTIVE IMAGE DISPLAY WITH DIELECTRIC LAYER
Semi-retro-reflective total internal reflection-based image displays may be equipped with at least one dielectric layer. The at least one dielectric layer may be deposited on one or more of a front electrode layer, rear electrode layer or pixel walls. This may lead to displays with enhanced brightness, improved electrophoretic particle responsiveness, improved grayscale and chemical stability in the presence of an electrophoretic medium, and improved resistance to high electric fields and high temperatures. In one embodiment, a total internal reflection-based image display comprises a dielectric layer formed by one or more of methods molecular layer deposition, atomic layer deposition, chemical vapor deposition, plasma enhance chemical vapor deposition, spin coating or slot die coating. In another embodiment, a total internal reflection-based image display comprises at least one dielectric layer and at least one surface modification layer.
Total internal reflection (TIR) based image displays comprise at least one high refractive index (> 1.5) convex protrusion interfaced with a low refractive index (< 1.5) medium. Total internal reflection of light is frustrated at this interface by movement of electrophoretically mobile particles into and out of the evanescent wave region. The size, shape and arrangement of the convex protrusions, typically in the shape of lenses, affects TIR at the interface and ultimately the brightness of the display. The brightness is a critical aspect of reflective displays. The degree of brightness determines what applications the displays may be used for and their ultimate acceptance by consumers. For example, high brightness displays allows for the use of color filter arrays for applications requiring color. The shape of the convex protrusions may be described by a polar coordinate system.
G02B 26/08 - Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
G02B 26/02 - Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the intensity of light
6.
METHOD, SYSTEM AND APPARATUS FOR COLOR SATURATION IN REFLECTIVE IMAGE DISPLAYS
Color images in electronically switchable reflective displays typically exhibit unsaturated color images due to their low brightness when compared to emissive displays (e.g. OLEDs, LEDs, LCDs). Combining a TIR-based display with a front light system, dynamic light sensor and frame detection system, images may be displayed with saturated colors on a frame-by-frame basis. Ambient light levels may be sensed such that the front light system may emit light in a controlled and minimized manner to substantially maintain the required per frame luminance for highly saturated colors when white subpixels may be dimmed or completely turned off. Such a system will also minimize the use of the power consuming front light system whenever possible. Minimizing light output may conserve energy and optimize battery life.
G02F 1/167 - 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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
G02F 1/315 - Digital deflection devices based on the use of controlled total internal reflection
G09G 3/34 - Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix by control of light from an independent source
7.
METHOD, APPARATUS AND SYSTEM FOR TOTALLY INTERNALLY REFLECTED HIGH GAIN LIQUID CRYSTAL DISPLAY
Conventional reflective liquid crystal displays (LCDs) suffer from low brightness and exhibit a metallic gray-like appearance. The disclosed embodiments describe a new display comprising a portion of a reflective LCD combined with a total internal reflection (TIR) based high gain reflector. The high gain reflector comprise a semi-retro-reflective sheet comprising of convex protrusions that reflects light that substantially retains the polarization of the incident light. The reflective display embodiments described herein increases the overall brightness compared to conventional LCDs and results in a more appealing paper-like appearance.
The totally-internally reflective (TIR) based reflective displays may be comprised of flexible or conformable components. TIR-based displays with flexible components may expand their use in a variety of applications such as those requiring novel designs, shapes or ruggedness. Flexible TIR-based displays may comprise spacers or sidewalls to maintain a substantially uniform spacing distance between the front and rear electrodes when the display is flexed or bent.
G02F 1/167 - 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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
9.
SHAPE DEPENDENT CONVEX PROTRUSIONS IN TIR-BASED IMAGE DISPLAYS
Brightness in total internal reflection image displays comprising of a color filter array may be enhanced by tuning the size and shape of the convex protrusions. Each protrusion or group of two or more protrusions may be aligned with a color filter sub-pixel such as red, green or blue, and with a thin film transistor. Each protrusion or group of two or more protrusions may be tuned to a specific size and shape with respect to the color filter sub-pixel it may be aligned with on a pixel by pixel basis. This may enhance the reflectance at the wavelength matching the desired color of the respective pixel.
G02F 1/15 - 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 an electrochromic effect
10.
METHOD AND APPARATUS FOR DRIVING STATIC IMAGES AND VIDEO FOR TIR-BASED IMAGE DISPLAYS
A total internal reflection-based display may be driven by an apparatus and method to move electrophoretically mobile particles into and out of an evanescent wave region to create static and video images. The apparatus may comprise one or more of a host microprocessor/controller, display controller, TIR display panel, frame buffer memory 1, frame buffer memory 2, host interface, temperature/environmental sensor, timing controller, look up table, power management integrated circuit or display panel interface.
G02F 1/167 - 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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
G02F 1/315 - Digital deflection devices based on the use of controlled total internal reflection
Optical states in TIR-based image displays may be modulated by movement of electrophoretically mobile particles into and out of the evanescent wave region at the interface of a high refractive index convex protrusions and a low refractive index medium. The movement of particles into the evanescent wave region may frustrate TIR and form dark states at pixels. Movement of particles out of the evanescent wave region may allow for TIR of incident light to form bright states at pixels. The movement of the particles may be controlled by employing the drive methods of pulse width modulation, voltage modulation or a combination thereof.
G02F 1/01 - 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
G02F 1/23 - 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 for the control of the colour
G02F 1/29 - 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 position or the direction of light beams, i.e. deflection
12.
LATERAL MIGRATION MITIGATION IN TIR-BASED IMAGE DISPLAYS
The disclosed embodiments relate to lateral migration of particles in a totally internally reflective displays. In certain embodiments, the reflective image displays include partial and full walls to form partitions within the display. The walls mitigate diffusion and lateral migration or drift of electrophoretically mobile particles due to lateral electric fields at adjacent pixels. This improves image quality, bistability and long-term display performance.
G02F 1/01 - 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
G02B 26/00 - Optical devices or arrangements for the control of light using movable or deformable optical elements
G02F 1/295 - 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 position or the direction of light beams, i.e. deflection in an optical waveguide structure
13.
TIR IMAGE DISPLAY WITH AN INDEX PERTURBATION ARRAY
Maximizing brightness in conventional total internal reflection image displays may lead to more applications where they may be used. A refractive index perturbation array may be used to enhance the brightness. Control of the size, spacing and refractive index in an index perturbation array layer may lead controlled diffraction of light and lead to enhanced brightness in total internal reflection image displays.
G02F 1/167 - 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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
G02B 5/124 - Reflex reflectors cube corner, trihedral or triple reflector type plural reflecting elements forming part of a unitary plate or sheet
G02B 26/00 - Optical devices or arrangements for the control of light using movable or deformable optical elements
G02F 1/01 - 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
Reflective image displays use minimal power but have limited use in low ambient conditions. Emissive image displays are intrinsically reflective and must use significantly more power in high ambient light conditions to optimize the image quality which greatly limits the battery life. To date no single display technology has been able to provide excellent image quality in all ambient lighting conditions. The embodiments described herein involves the efficient hybridization of controlled reflection with controlled efficient emission to improve both the practicality and the overall performance of the display.
G02F 1/167 - 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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
G02B 26/00 - Optical devices or arrangements for the control of light using movable or deformable optical elements
G02B 26/02 - Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the intensity of light
G02F 1/01 - 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
G02F 1/19 - 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-reflection or variable-refraction elements not provided for in groups
G02F 1/315 - Digital deflection devices based on the use of controlled total internal reflection
G09G 3/34 - Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix by control of light from an independent source
15.
METHOD AND APPARATUS FOR AN ENHANCED BRIGHTNESS TIR IMAGE DISPLAY
Brightness in conventional total internal reflection image displays may decrease due to incident light passing through the dark pupil region in the white state. Certain embodiments of the disclosure relate to an enhanced brightness total internal reflection-based image display utilizing a front sheet having an array of modified hemispherical protrusions with a partially light reflective surface. Modifying the structure of the convex protrusions of the transparent front sheet and adding a light reflective layer on specific areas of the protrusions may increase brightness in the white state. Controlling the size, depth and angle of the structure of the convex protrusions may direct incident light by one or more of total internal reflection and specular reflection in a controllable manner to enhance brightness of the display.
G02F 1/167 - 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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
B01J 13/02 - Making microcapsules or microballoons
G09G 3/20 - Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix
G06F 3/038 - Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
G09G 3/34 - Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix by control of light from an independent source
16.
METHOD AND APPARATUS FOR TWO PARTICLE TOTAL INTERNAL REFLECTION IMAGE DISPLAY
Brightness in total internal reflection image displays may be enhanced by addition of a plurality of light reflecting particles. The particles may be charged, uncharged or weakly charged. The particles may be designed such that they do not enter the evanescent wave region and frustrate TIR when near the surface of the convex protrusions but be close enough to reflect light rays that pass through the dark pupil region to enhance brightness.
G02F 1/315 - Digital deflection devices based on the use of controlled total internal reflection
G02F 1/167 - 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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
G02F 1/136 - Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
Brightness in conventional total internal reflection image displays may decrease due to incident light passing through the dark pupil region in the white state. Adding sub-wavelength structures to the surface of the convex protrusions on the transparent front sheet may increase brightness in the white state. Control of the size, spacing, shape and refractive index of the sub-wavelength structures may lead to zeroth order reflection and enhanced brightness.
G02F 1/1335 - Structural association of cells with optical devices, e.g. polarisers or reflectors
G02F 1/19 - 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-reflection or variable-refraction elements not provided for in groups
G03F 7/00 - Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printed surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
18.
BISTABILITY ENHANCEMENT IN TOTAL INTERNAL REFLECTION IMAGE DISPLAYS
Total internal reflection image displays are equipped with a bistability enhancement particle interaction layer. The bistability enhancement layer imparts bistability in the display at 0V or power off. The bistability enhancement layer may hold particles near the surface in the evanescent wave region at the front electrode at 0V or power off to retain a dark state image. The particle interaction layer may hold particles near the surface of the rear electrode at 0V or power off to retain a bright state image. Control of particle density improves bistability.
G02F 1/167 - 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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
G02B 5/128 - Reflex reflectors including curved refracting surface transparent spheres being embedded in matrix
G02F 1/315 - Digital deflection devices based on the use of controlled total internal reflection
19.
MULTI-ELECTRODE TOTAL INTERNAL REFLECTION IMAGE DISPLAY
Conventional total internal reflection image displays consist -of mobile particles of a single charge arid capable of displaying information consisting of two different optical states. The reflective image display embodiments described herein comprises particles of different charge states and optical characteristics in combination with multi-electrode arrays. This may allow for displaying information consisting of at least three different optical states.
G02F 1/167 - 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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
20.
HIGH REFRACTIVE INDEX COMPOSITES FOR REFLECTIVE DISPLAYS
To maximize the critical angle, θc, and the reflectance, R, in total internal reflection reflective image displays, the difference in the refractive indices between the surface of the transparent front sheet and the liquid medium comprising of electrophoretically mobile particles must be maximized. High index optical glasses may be used to fabricate the front sheet but are costly and difficult to manufacture with fine structural features. Polymers may be used to fabricate the transparent front sheet as they are cheaper and simpler to process into desired structures but typically have low indices of refraction. Polymers comprising of dispersed high refractive index particles may be used to increase the refractive index of the transparent front sheet. The polymers may be formed from UV-curable liquid monomers.
G02B 5/128 - Reflex reflectors including curved refracting surface transparent spheres being embedded in matrix
G02F 1/167 - 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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
G02F 1/315 - Digital deflection devices based on the use of controlled total internal reflection
The disclosure generally relates to image displays. Specifically, the application relates to an overlay that, among others, enhances the brightness in image displays with color filters. Much of the incoming light to a reflective image display having a color filter layer is absorbed by the color filter layer and is therefore lost. An overlay embodiment is disclosed herein that disperses and concentrates portions of the incoming light onto specific portions of the display. The amount of light absorbed by the color filter layer may be drastically reduced and instead transmitted through the color filter where the light may be reflected or absorbed by a light modulating layer. The disclosed embodiments increase the efficiency and reflectance of the display.
G02F 1/167 - 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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
A high efficiency, long life, video rate, electrophoretic display comprises fluid containing sub-pixel structures that are periodic, and aligned with a color filter array. A fluid comprising of electrophoretically mobile particles is compartmentalized at the size scale of the individual filters (one per filter) such that the particles may be moved to either allow light to be returned through the same filter back towards the viewer by total internal reflection (TIR) or conventional reflection to create a light state or to be absorbed by the particles to create a dark state. High reflectance is achieved through the use of structures that avoid ITO layers in the light path and reflecting most light, by virtue of a dual control of light by TIR and transmission to a reflector. In one embodiment the structures are in the shape of truncated pyramids.
G02B 17/00 - Systems with reflecting surfaces, with or without refracting elements
G02F 1/19 - 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-reflection or variable-refraction elements not provided for in groups
23.
TWO PARTICLE TOTAL INTERNAL REFLECTION IMAGE DISPLAY
A totally internally reflective image display having a first electrically charged particle and a second electrically charged particle of opposite charges are disclosed. By applying a non-zero voltage the particles are moved such that they frustrate total internal reflection and create a dark state. By applying a zero voltage and/or voltage pulsing, light is totally internally reflected to create a light state. The display is DC balanced and compatible with common drive electronics. Multi-colored displays may be created using first and second particles with different optical characteristics.
Semi-retro-reflective, semi-specular, specular and etched glass displays are equipped with a dielectric layer. This leads to displays with enhanced brightness, improved electrophoretic particle responsiveness, improved grayscale and chemical stability in the presence of an electrophoretic medium, electric field and high temperatures. In one embodiment, a reflective image display comprises a front sheet further comprising a plurality of hemispherical protrusions, front and rear electrodes, a dielectric layer on the surface of at least one electrode, liquid medium with electrophoretically mobile particles, color filter array layer and a directional front light system.
G02F 1/167 - 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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
25.
METHOD AND APPARATUS FOR HIGH RESOLUTION REFLECTIVE IMAGE DISPLAY
A reflective image display comprising of a rigid and thermally stable layer is proposed where light is reflected in a semi-specular or semi-retro-reflective manner or absorbed by electrophoretically mobile particles. The layer is comprised of a plurality of cavities such as in the shape of hemispheres in hourglass-like shapes where the lateral displacement of the optical path of light entering and exiting the display is less than the width of the pixels leading to a high resolution reflective image display
G02F 1/167 - 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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
26.
METHOD AND APPARATUS FOR FRONT-LIT SEMI-RETRO-REFLECTIVE DISPLAY
The disclosure generally relates to a front-lit display having transparent and selectively emissive light directionality. The disclosed semi-retro-reflective, semi-specular and specular displays include directional front light systems that reflect light in a manner to preserve the non-Lambertian characteristic of the light output. This leads to brighter displays with a higher degree of luminance as compared to conventional microencapsulated electrophoretic displays with substantially Lambertian reflectance where much of the light is not reflected back towards the viewer.
G02F 1/167 - 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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis