Abstract: A light modulator comprises a plurality of discrete variable transmission electro-optic layers arranged so that light will pass successively through the plurality of layers; the light modulator has a higher transmission range than any of the individual electro-optic layers separately.

Abstract: Various improvements in electrophoretic media and displays intended for use in light modulators are described. These improvements include index matching of the suspending fluid to a continuous phase surrounding the fluid, index matching of a capsule wall to a binder, planarization of a layer containing electrophoretic capsules before application of adhesive thereto, methods for concentrating electrophoretic particles into limited areas of sidewalls of electrophoretic capsules or microcells in the light-transmissive state of the display, and, in the case of light modulators comprising an electrophoretic layer sandwiched between two transparent plates, forming at least one of the plates so as to absorb electromagnetic radiation which adversely affects the electrophoretic layer.

Abstract: A coating of an encapsulated electrophoretic medium is formed on a substrate (106) by dispersing in a fluid (104) a plurality of electrophoretic capsules (102), contacting at least a portion of a substrate (106) with the fluid (104); and applying a potential difference between at least a part of the portion of the substrate (106) contacting the fluid (104) and a counter-electrode (110) in electrical contact with the fluid (104), thereby causing capsules (102) to be deposited upon at least part of the portion of the substrate (106) contacting the fluid (102). Patterned coatings of capsules containing different colors may be deposited in registration with electrodes using multiple capsule deposition steps. Alternatively, patterned coatings of capsules may be formed by applying a fluid form of an electrophoretic medium to a substrate, and applying a temporally varying voltage between an electrode and the substrate. The process may be repeated to allow for deposition of full color displays.

Abstract: An electrophoretic display comprises a pair of facing substrates, at least one of which is transparent, a plurality of particles and a gas between the substrates, and means for applying an electric field to cause the particles to move and thus change the electro-optic state of the display. The electric field means is arranged to increase the impulse applied to the display with increasing time since a reference time, or with increasing number of images written on the display. In another embodiment, an alternating current pulse is applied to the display, and the duration and/or amplitude of the alternating current pulse is increased with increasing time since a reference time.

Abstract: Methods are provided for of driving a bistable electro-optic display having at least first and second pixels separated by an inter-pixel gap. In one method, there is applied to the first pixel a drive pulse which drives the pixel to one extreme optical state, and there is applied to the second pixel, which is in this extreme optical state, a reinforcing pulse of the same polarity as the drive pulse. In a second method, a drive pulse applied to the first pixel drives that pixel away from one extreme optical state, and an inverse reinforcing pulse applied to the second pixel is of opposite polarity to the drive pulse. The drive methods reduce edge ghosting or blooming.

Abstract: An electrophoretic medium comprises a fluid and a plurality of electrically charged particles disposed in the fluid and capable of moving therethrough on application of an electrical field to the medium. Each of the charged particles has a polymer coating comprising a first group. A polymer is dispersed in the fluid, this polymer having a plurality of second groups capable of attracting the first groups on the particles so that the polymer in the fluid forms a complex with the electrophoretic particles.

Abstract: A particle for use in an electrophoretic display comprises a light-scattering inorganic core and a light-transmissive colored shell of an organic pigment. The core may be titania and the shell may be formed of particles having an average particle size less than 700 nm. The particles are produced by treating a light-scattering inorganic pigment with a polymer which adsorbs on both the inorganic pigment and an organic pigment; and adding the organic pigment and allowing the organic pigment to mix with the polymer-coated inorganic pigment. The particles may have a polymer coating.

Abstract: A bistable electro-optic display has a plurality of pixels, each of which is capable of displaying at least three gray levels. The display is driven by a method comprising: storing a look-up table containing data representing the impulses necessary to convert an initial gray level to a final gray level; storing data representing at least an initial state of each pixel of the display; receiving an input signal representing a desired final state of at least one pixel of the display; and generating an output signal representing the impulse necessary to convert the initial state of said one pixel to the desired final state thereof, as determined from said look-up table. The invention also provides a method for reducing the remnant voltage of an electro-optic display.

Abstract: An electrophoretic medium (100) comprises at least one type of particle (108) suspended in a suspending fluid (106) and capable of moving therethrough on application of an electric field to the medium, the particles (108) including at least one electrophoretically mobile specularly reflective particle.

Abstract: A first apparatus for displaying drawings comprises a housing having an aperture, a drawing sheet comprising electro-optic material movable through the aperture between closed and open positions, and a writing device for writing on the sheet as it moved between its closed and open positions. A second apparatus comprises a display member having a viewing surface, support means for supporting this display member above a floor, an electro-optic medium disposed on the display member, and a movable writing head for writing on the electro-optic medium. Another display comprises an optic medium with two display states visible through a viewing surface. A touch screen is disposed on the opposed side of the optic medium from the viewing surface, and the optic medium is deformable such that pressure applied to the viewing surface will be transmitted to the touch screen.

Abstract: A system for centrally controlling and messaging electrically active displays distributed at a single site or at multiple sites. A process for creating an electronically addressable display includes multiple printing operations, similar to a multi-color process in conventional screen printing. In some of the process steps, electrically non-active inks are printed onto areas of the receiving substrate, and in other steps, electrically active inks are printed onto different areas of the substrate. The printed display can be used in a variety of applications. This display can be used as an indicator by changing state of the display after a certain time has elapsed, or when a certain pressure, thermal, radiative, moisture, acoustic, inclination, pH, or other threshold is passed. In one embodiment, the display is incorporated into a battery indicator. A sticker display is described. The sticker is adhesive backed and may then be applied to a surface to create a functional information display unit.

Abstract: An electro-optic display comprises a layer of solid electro-optic material; a backplane comprising at least one electrode; and an adhesive layer disposed between the layer of electro-optic material and the backplane and adhesively securing the layer of electro-optic material to the backplane, the adhesive layer comprising a thermally-activated cross-linking agent comprising an epoxidized vegetable oil fatty acid or an epoxidized ester of such a fatty acid. The cross-linking agent reduces void growth when the display is subjected to temperature changes.

Abstract: Novel addressing schemes for controlling electronically addressable displays include a scheme for rear-addressing displays, which allows for in-plane switching of the display material. Other schemes include a rear-addressing scheme which uses a retroreflecting surface to enable greater viewing angle and contrast. Another scheme includes an electrode structure that facilitates manufacture and control of a color display. Another electrode structure facilitates addressing a display using an electrostatic stylus. Methods of using the disclosed electrode structures are also disclosed. Another scheme includes devices combining display materials with silicon transistor addressing structures.

Abstract: An electrophoretic display comprises an electrophoretic medium having a plurality of charged particles suspended in a suspending fluid, and two electrodes disposed on opposed sides of the electrophoretic medium. At least one of the electrodes is light-transmissive and forming a viewing surface. The display has a closed optical state in which the charged particles are spread over substantially the entire viewing surface so that light cannot pass through the medium, and an open optical state in which the electrophoretic particles form chains extending between the electrodes so that light can pass through the electrophoretic medium. Insulating layers are disposed between the electrodes and the electrophoretic medium. Similarly electrophoretic displays are provided equipped with color filter arrays or reflectors.

Abstract: A flexible electro-optic display comprises a layer of solid electro-optic material; a backplane comprising at least one electrode arranged to apply an electric field to the layer of electro-optic material; and an adhesive layer disposed between the layer of electro-optic material and the backplane and adhesively securing the layer of electro-optic material to the backplane, the adhesive layer having a storage modulus (G?) of at least about 104 Pascals at 10?3 Hz and 70° C.

Abstract: An electro-optic display comprises a bistable electro-optic material having a viewing surface and an opposed writing surface; a deformable member disposed adjacent but spaced from the writing surface of the electro-optic material, and bearing elongate electrodes facing the writing surface of the electro-optic material; and a movable member disposed on the opposed side of the deformable member from the electro-optic material and movable parallel to the elongate electrodes, the movable member contacting and deforming the deformable member such that a portion of each elongate electrode contacts or lies closely adjacent the writing surface of the electro-optic material.

Abstract: Ink jet printing can be used in the production of electro-optic displays for (a) forming a layer of a polymer-dispersed electrophoretic medium on a substrate; (b) forming a color electro-optic layer; (c) forming a color filter; and (d) printing electrodes and/or associated conductors on a layer of electro-optic material.

Abstract: A front plane laminate (see U.S. Pat. No. 6,982,178) is produced by forming a sub-assembly comprising a lamination adhesive layer and an electro-optic layer, forming an aperture through the sub-assembly, and securing a light-transmissive electrode layer to the sub-assembly so that the electrode layer extends across the aperture. Alternatively, formation of the aperture is omitted, and the electrode layer has a tab portion extending beyond the edges of the lamination adhesive and electro-optic layers. When a front plane laminate is secured to a backplane to form an electro-optic display, a stiffening layer may be attached to either part to increase its stiffness, then removed after the lamination. An electro-optic display or front plane laminate may use an adhesive layer comprising separate layers of cross-linked and non-cross-linked adhesive.

Abstract: An electro-optic display (100) comprises a backplane (102); an electro-optic layer (112) adjacent the backplane (102), the electro-optic layer (112) being smaller than the backplane (102) so as to leave a peripheral portion of the backplane extending beyond the edges of the electro-optic layer (112); and a protective layer (118) disposed on the opposed side of the electro-optic layer (112) from the backplane (102), a peripheral portion of the protective layer (118) extending beyond the edges of the electro-optic layer and being adhered (at 120) to the backplane (102).

Abstract: A front plane laminate useful in the manufacture of electro-optic displays comprises, in order, a light-transmissive electrically-conductive layer, a layer of an electro-optic medium in electrical contact with the electrically-conductive layer, an adhesive layer and a release sheet. This front plane laminate can be prepared as a continuous web, cut to size, the release sheet removed and the laminate laminated to a backplane to form a display. Methods for providing conductive vias through the electro-optic medium and for testing the front plane laminate are also described.