Abstract: An image display comprises: a display device having an image output surface at which an image is displayed as a spaced array of pixel elements; an image guide (20) coupled to the image output surface of the display device and comprising a plurality of light transmission guides (80) each having an input end and an output end, the input ends of the light transmission guides being arranged relative to one another so that groups of one or more light transmission guides receive light from respective groups of one or for a cluster comprising at least a subset of the light transmission guides (80): at the outer periphery of the cluster, the input ends of the light transmission guides are constrained against expansion by a frame formed of a material having thermal expansion properties which are substantially similar to the thermal expansion properties of the image output surface.

Abstract: An image display is disclosed comprising an image display device with a light emitting surface having an array of picture elements; a light guide formed from a plurality of light transmission guides with the input to each light transmission guide being provided by a sub-array of a plurality of picture elements from the light emitting surface of the image display device and luminance correction means to assign a colour component value and a dither fraction value to each sub-array of a plurality of picture elements on the light emitting surface of the image display device. Assigning a colour component value (120) and a dither fraction value (122) to each sub-array of picture elements on the image display device can correct for differences related to individual image display device or light guide non-uniformity at the individual pixel level or for differences between image displays when used with multiple image display devices.

Abstract: An image display comprises an image display device for generating a viewable image; and an optical angular selector (290) for selecting an angular range of light to form the viewable image, the optical angular selector having an array of substantially parallel light transmission guides (260) each comprising a light-guiding region (270) to promote propagation of light incident upon the light-guiding region within a range of angles of incidence by refraction and/or total internal reflection and an absorbing material (310) peripherally arranged with respect to the light-guiding region to absorb light incident upon the light-guiding region outside the range of angles of incidence.

Abstract: A combination of a relatively low backscatter diffuser with a specularly reflective or weakly scattering transducer to achieve the required front of screen properties for a paper-like display. The diffuser, which may be of the volume or surface relief type, in enclosed in the display cell. The transducer may be any one of several electro-optically active materials such as a liquid crystal, electrochromic or electrophoretic types.

Abstract: An improved orientation system includes a lens pre-distorting an image generated by imaging apparatus such that a non-linearity, the degree of which is dependent on the off-axis distance of an imaged object, is generated so as to increase the strength of a signal indicating said non-linearity.

Abstract: A matrix addressed display device having a cathode means and grid electrode means comprising an orthogonal array of parallel row conductors and parallel column conductors in which means are providing for selectively applying cut-off and gain correction information to the row conductors and the column conductors. The cut-off and gain correction information may be applied so as to affect all of the display area equally and correct for warm up drift, or it may be applied so as to correct for the effect of a discrete number of hot cathode filaments being used or it may be applied on a pixel by pixel basis.

Abstract: An improved orientation system includes a lens pre-distorting an image generated by imaging apparatus such that a non-linearity, the degree of which is dependent on the off-axis distance of an imaged object, is generated so as to increase the strength of a signal indicating said non-linearity.

Abstract: A cholesteric liquid crystal display (LCD) having a reduced dependency between viewing angle and color is achieved by the addition of a weak diffuser to the front surface of the liquid crystal material. The diffuser diffuses both light incident on the surface of the liquid crystal material and light reflected from the liquid crystal material over a wide range of angles. Thus, at any one viewing angle a viewer will observe light that was incident on the display and reflected from it over a wide range of angles. As well as reducing the dependency between viewing angle and color, the addition of the diffuser broadens the range of wavelengths of light reflected by the LC material when it is in a reflective state.

Abstract: A reflective liquid crystal display has a quarter wave plate and a film of fluorescent material located between a compartment containing a guest-host liquid crystal material and a reflector. In the dark state, light which has been reflected from the reflector excites the fluorescent layer. The light emitted by the fluorescent layer is absorbed by the guest-dye molecules in the liquid crystal and so does not exit from the compartment to the viewer. In the light state, light which has been reflected from the reflector excites the fluorescent layer. The light emitted by the fluorescent layer passes through the guest dye molecules in the liquid crystal display and exits from the guest dye molecules in the liquid crystal display and exits from the compartment to the viewer, thus enhancing the reflectivity of the display in the light state without degrading the dark state, thus enhancing the contrast ratio.

Abstract: The present invention relates to a light-modulating composition comprising a low molecular weight liquid crystalline material dispersed in a polymer including a non-mesogenic crosslinking monomer reacted with a mesogenic monomer comprising a mesogenic group, a spacer, and one or more reactive functionality.

Abstract: Display apparatus comprising a display screen for the display of an image to be viewed by a user. The display apparatus has one or more eye trackers for monitoring the eye motion of the user. The motion detected is processed to calculate an effective displacement of the image caused by the eye motion. The image displayed on the screen is moved to compensate for the effective displacement caused by the eye motion. The display apparatus may have an image displayed on the screen which has a background which is light in color, the area of the display screen surrounding the displayed image may be dark in color. The periphery of the displayed image is graduated so as to be the same as the area of the display screen surrounding the displayed image at the outer periphery and the same as the background of the image at the inner periphery.

Abstract: A bistable liquid crystal display cell comprises at least two compartments separated by thin transparent membranes. A first compartment contains a first liquid crystal mixture between a first substrate and a thin transparent membrane. A second compartment contains a second liquid crystal mixture between a second substrate and a thin transparent membrane. The mixtures have a first alignment in which they are both aligned parallel to the plane of the display cell, but orthogonal to each other, and a second alignment in which they are both aligned normal to the plane of the display cell. Each compartment has a grating located on a surface of the compartment.

Abstract: An electron source comprises at least one cathode means, and at least one extractor grid which is used to extract electrons from the cathode means. The extractor grid is a substantially planar sheet having at least one aperture and also has at least one spacing member for spacing the extractor grid at a constant, predetermined spacing from the cathode. Each of the spacing members are formed by removing material around a substantial portion of the periphery of the aperture and folding the remaining portion of the periphery of the aperture at substantially a right angle to the planar sheet.

Abstract: A photo-cathode electron source suitable for use in flat panel displays has an extractor grid means (104) maintained, in use, at a positive potential with respect to the photo-cathode surface. The extractor grid may be used as a carrier for unfired photoemissive material which forms the emission surface of the photo-cathode. The material is deposited on the surface (103) of the photo-cathode means (102) by means of evaporation from the extractor grid (104).

Abstract: A display device having a selectively reflective layer inside the display cell is described. By incorporating the selectively reflective layer inside the display cell itself, enhanced reflectivity is produced from the scattering state, but the problem of parallax is substantially avoided.

Abstract: An input device for a visual display comprising a light source and a scanner for angularly scanning a light beam from the light source across a plane. A photodetector detects interruption of the beam by an article positioned in the plane. The scanner comprises a shutter having a linear array of addressable, electrically actuable shutter elements. Each element is operable to transmit or block light from the light source under the control of a corresponding electrical signal. Because the light beam is scanned by a shutter rather than a mechanical scanner, the device is advantageously more reliable than conventional electromechanical optical input devices.

Abstract: A novel multi-layer display cell is disclosed in which contrast ratios similar to that available from cells which use polarisers are achieved, as well as levels of reflectivity similar to that available from cells that do not use polarisers. This is achieved by using two or more compartments for the display cell separated by dielectric membranes. The electro-optic characteristics of the mixture in the two compartments differs in that the mixture in one of the compartments switches at a low voltage, being switched completely below the switching threshold of material in the other of the compartments.

Abstract: An electrochromic display and a method for making thereof are disclosed. The display has isolated and perforated reflectors separating an electrolyte confined between two electrodes. The front electrode is transparent. The reflector eliminates the need to include pigment particles in the electrolyte to mask the black rear electrode and to provide a desired color background. The pigment free electrolyte is thinner than a pigmented electrolyte. The reflector reflects light back to the transparent electrode thus masking the rear electrode and providing a background color other than black. When the rear electrode is driven by a drive circuit, ions of the electrolyte and current pass through the reflector towards the front electrode, where a coloration reaction occurs to form an image. The electrochromic display is thin, has high resolution, and does not exhibit image spreading and distortion.

Abstract: A display having an electrically variable diffuser is disclosed. In response to an electric field, the electrically variable diffuser is electrically switched from a low illumination/narrow viewing angle mode to a high illumination/wide viewing angle mode. The viewing angle is correlated with backlight luminance to provide an adequate display as the viewing angle is varied. This allows a user to choose between preserving battery life and maximizing viewing angle.

Abstract: This invention relates to a novel cell construction which enables stacked cells to be formed in which the intermediate substrate is so thin that little or no parallax occurs between the images formed in the two or more cells. In addition, the thickness of the intermediate substrate is such that the field drop across is is low (about 10%) compared to that across the liquid crystal layers, and the stacked cell can be addressed as a single cell. This greatly simplifies and reduces the cost of the interconnections and drive electronics. The avoidance of the need for transparent electrodes on both surfaces of the intermediate substrate also improves transmittance (and reflectivity) of the device. Of course, should it be required, the intermediate substrate can be patterned with transparent electrodes in the conventional way. The advantage of substantially zero parallax would remain.