Abstract: A three dimensional display is provided which can. operate in an autostereoscopic mode, requiring no viewing aid, and a stereoscopic mode, requiring a viewing aid such as polarized spectacles. In the autostereosocopic mode, light from illuminators is imaged by lenses through LCD display panels at regions where the left and right eyes of an observer are located. Thus, a two dimensional image displayed on one panel is visible to the right eye of the observer whereas a two dimensional image displayed by the other panel to visible to the left eye of the observer. In the stereoscopic mode, light from the illuminators through the LCD panels is visible throughout an extended region by both eyes of the observer. However, the light from the panels is polarized in mutually perpendicular directions and the spectacles comprise polarizers for the left and right eyes which substantially pass only light corresponding to the left and right images, respectively.

Abstract: Disclosed herein is an apparatus for maintaining and converting a localized polarization shift into a localized intensity variation in a liquid crystal display assembly. The assembly includes a liquid crystal display having a back side and a front side, a polarization-maintaining, light-diffusing layer adjacent to the front side of the liquid crystal display, and a front light-polarizing layer disposed adjacent to the polarization-maintaining, light-diffusing layer. A method for maintaining and converting a localized polarization shift into a localized intensity variation in a liquid crystal display assembly also is disclosed.

Abstract: Lithography processes that use multiple layers require registration between layers. The accuracy requirement depends on the application of the lithograph. For microlithography, the registration requirement could be less than one micron. Systems that use lenses for imaging such as optical steppers can image conventional alignment marks through those lenses. A unique microlithography system that employs holograms has properties that are not compatible with known alignment techniques. The present invention is a new system for alignment of holographic microlithography elements.

Abstract: A light source comprises an array of contiguous transparent blocks, each of which contains a light emitter such as a cold cathode fluorescent tube. The blocks have a transparent front surface which may be optically diffusing, the other surfaces being coated with a thin optically reflective layer so that each block acts as a light guide. The tubes are independently controllable, for instance so as to simulate a moving light source which may be controlled so as to track the position of an observer of a 3D display.

Abstract: Left eye and right eye images of an autostereoscopic display are displayed on LCD spatial light modulators which are illuminated by movable light sources via converging lenses or mirrors. A tracking system tracks the position of an observer and a control system controls the positions of the light sources so that the images of the light sources formed by the lenses or mirrors track the observer. The observer thus sees the 3D image while having an enlarged degree of freedom of movement.

Abstract: An autostereoscopic display of the invention includes: an illumination source for producing light of a first polarization and light of a second polarization different from the first polarization; a spatial light modulator for modulating the light of the first polarization and the light of the second polarization from the illumination source; and an optical system for directing the light of the first polarization to a first viewing region and the light of the second polarization to a second viewing region, wherein the spatial light modulator includes: a first polarization adjusting member for transmitting the light of the first polarization and substantially preventing transmission of the light of the second polarization; a second polarization adjusting member for transmitting the light of the second polarization and substantially preventing transmission of the light of the first polarization; and first and second groups of picture elements optically aligned with the first and second polarization adjusting mem

Abstract: An observer tracking display is provided in which the image data displayed by at least three image displays along respective different directions is updated depending on the lateral position of an observer. The image displayed in a viewing region not visible to the observer is updated with an appropriate image in anticipation of the observer moving to a position where that viewing region is visible.

Abstract: A calibration method is provided for an observer tracking display, for instance of the autostereoscopic 3D type, which forms steerable viewing zones and which comprises a tracking system for tracking an observer and a controller for controlling the viewing zones in response to the tracking system. The viewing zones are steered to direct light in a plurality of directions in turn. The observer then moves to the optimum position for viewing the display. The tracking system determines the optimum position for each viewing zone direction and the positions and directions are stored in association with each other so as to form a mapping in the controller for controlling the viewing zones in response to the tracking system during normal use of the display.

Abstract: An autostereoscopic display has first and second spatial light modulators. Images from the spatial light modulators are combined by a beam combiner before being presented to a viewing region. The relative positions of the first and second spatial light modulators are controlled such that pixels of the second spatial light modulator are interspersed with pixels of the first spatial light modulator. Such an arrangement allows an effective doubling of resolution when the spatial light modulators are operated so as to produce a two dimensional image instead of a three dimensional images.

Abstract: The number of 2D views available to form an autostereoscopic 3D image is increased by using a beam combiner with two displays. Each display may comprise sequentially illuminatable light sources imaged by converging lenses for illuminating sequentially reproduced 2D images in spatial light modulators. The views are combined by the beam combiner so as to be visible to an observer in different directions corresponding to the directions from which the views were recorded during image capture.

Abstract: A 3D projection display comprises an autostereoscopic image producing unit which directs light beams corresponding to respective 2D views in different directions towards a projection lens. The projection lens co-operates with the image producing unit to image the light beams at respective different regions in the aperture of the projection lens. A light-transmissive screen co-operates with the image producing unit and the projection lens to image the views at the screen. The screen may comprise a Fresnel lens, or where a magnified image of increased angular spread is required, a double lenticular screen angular amplifier.