Abstract: A high efficiency polarizing converter receives generally collimated light of arbitrary polarization and converts it to light of a selected polarization with minimal loss or absorption of light. In one embodiment, the polarizing converter has a generally planar configuration that is suitable for flat panel displays, LCD projectors, and other display applications.

Abstract: A visual display device is provided for delivering a generated image, preferably combinable with environment light, to the eye of a user. Light from an image generator such as a CRT, LED or LCD is reflected from a fold mirror away from a user's eye towards a combiner. The image is reflected from the combiner and magnified, optionally combined with light from the environment and passes back through the fold mirror towards the eye of the user. In one embodiment, an optical element such as a meniscus lens or PCX lens is used to present the user with a substantially flat focal field and/or a Fresnel lens or diffractive optical element is used to aim rays from the image to the field curvature corrective lens in order to maintain maximum contrast.

Abstract: An image display system such as an LCD projection display includes an illumination homogenizer and a centrifugal relay lens system. The illumination homogenizer, such as a reflective tunnel homogenizer or integrator, efficiently provides uniform distribution of light over a region matched to the configuration of an LCD, or other type of image source. The centrifugal relay lens system includes, for example, an S-curve aspheric lens surface that functions to increase the illumination distribution toward the edges and corners of the image source relative to the center. The projection system provides illumination with improved uniformity and efficiency while also providing a shortened optical pathway.

Abstract: Method and apparatus for providing gray level addressing for passive liquid crystal display (LCD) panels having overlapping row and column electrodes defining pixels are disclosed. Depending upon whether the rows are being addressed by "standard" or "Swift" addressing, the signals for applying to the column electrodes are determined by different calculations, in all of which modes the amplitudes of the column signals are related to the gray level desired to be displayed by the individual pixels. For a split interval system, column signals of appropriate amplitude and polarity are applied during different subintervals of a characteristic time interval of the display panel depending upon the method of addressing the rows. In the full interval mode, the column signals applied over a full time interval are based on the desired gray level of all the pixels in the column, adjusted to provide the proper rms voltage across all the pixels so that they display the desired gray levels.

Abstract: The present invention includes an invertible and orthoscopic LCD projector having a LCD panel for providing display information that is projected toward a display screen to form a display image. In a preferred embodiment, a converging Fresnel lens is positioned to receive the display information from the LCD panel and form a display object corresponding to the display image. The converging Fresnel lens has an optical center offset from the optical center of the LCD panel in an elevation direction and defines a projection optical axis that extends toward the display screen along an elevation angle in the elevation direction. The Fresnel lens is tilted automatically about a tilt axis transverse to the projection optical axis and the elevation direction by an amount proportional to the elevation angle to cooperate with the offset of the Fresnel lens optical center to form an orthoscopic display image.

Abstract: A conventional illumination system is supplemented by auxiliary reflectors to "fill-in" corner areas of a rectangular frame, providing more uniform illumination. The auxiliary reflectors intercept light that is emitted from the source in directions away from the system's condenser lens and any primary reflector, resulting in increased efficiency.

Abstract: Method and apparatus for providing gray level addressing for passive liquid crystal display (LCD) panels having overlapping row and column electrodes defining pixels are disclosed. Depending upon whether the rows are being addressed by "standard" or "Swift" addressing, the signals for applying to the column electrodes are determined by different calculations, in all of which modes the amplitudes of the column signals are related to the gray level desired to be displayed by the individual pixels. For a split interval system, column signals of appropriate amplitude and polarity are applied during different subintervals of a characteristic time interval of the display panel depending upon the method of addressing the rows. In the full interval mode, the column signals applied over a full time interval are based on the desired gray level of all the pixels in the column, adjusted to provide the proper rms voltage across all the pixels so that they display the desired gray levels.

Abstract: A polarization converter for polarizing a light beam by converting all light waves to the same orientation comprises 1) a first beam dividing matrix of refractory material for dividing a single, large light beam into smaller sub-beam 2) a second beam focusing matrix for polarizing select portions of the sub-beams, and 3) a series of narrow and shallow polarizing cells. The second beam focusing matrix further comprises a plurality of concave lenses for redirecting each sub-beam and quarter wave retarders disposed in alignment with, and adjacent to, the reflective side of an equal plurality of mirror segments. The polarizing cells include either a first beamsplitter or a second beamsplitter, where the first beamsplitters and second beamsplitters are disposed in opposing diagonal fashion and in an alternating manner.

Abstract: A projection system includes a collection lens that minimizes apparent magnification of the light source, so that the resulting system more nearly conforms to a point source idealization. Attendant benefits include improved collimation, a smaller projection lens, and a greater depth of focus. The collection lens is desirably of a "wrap around" configuration to maximize light collection while contributing to reduced source magnification. The opposite side of the collection lens can be provided with a convex lens of Fresnel form. Use of the Fresnel optic moves the principal plane of the collection lens closer to the light source, further minimizing the source's apparent magnification. The projection system additionally includes condensing optics formed with a deliberate asymmetry so as to provide more uniform illumination of a rectangular image plane. The Fresnel surface of the collection lens can be designed to provide this asymmetry.

Abstract: The present invention includes a projector illumination system having a light source positioned between a condenser lens and a light-collecting reflector. The light source includes a bulb that is urged under compression against a surface of the condenser lens. The condenser lens receives a flow of cooling air over a surface opposite that against which the light source is in contact to minimize deformation of the condenser lens caused by heat emanating from the light source.

Abstract: An LCD projector includes: a light source assembly for supplying light source required for the LCD projector; an image generating mechanism for generating image to be projected, having an LCD panel; a projection objective lens assembly for projecting the image generated by the image generating mechanism onto a screen; and a cooling mechanism for cooling off the surface of the LCD panel of which the temperature is raised due to the radiation of the light source. A thermal diffusion film having good transparency and thermal diffusivity is attachd to the surface of the LCD panel on the one side nearer to the light source assembly so as to facilitate homogeneous thermal diffusion in the surface of the LCD panel, and thus prevent deterioration of quality of projected image due to thermal shimmering caused by cooling air flow coming from the cooling mechanism.

Abstract: The present invention includes a LCD projector having a light source for directing light through a LCD and a projection lens assembly toward a display screen to form a display image. The light source and the LCD being encased within a main projector housing. The projection lens assembly being supported and carried by a retractable carrier between operating and stowage positions. In a preferred embodiment, the retractable carrier positions the projection lens assembly in its operating position outside the main body housing.

Abstract: Method and apparatus are disclosed for providing gray level addressing for passive matrix liquid crystal display (LCD) panels having pixels defined by overlapping row and column electrodes. The pixels have optical states determined by the rms voltage appearing across the pixels during a frame period. The frame period is divided into characteristic time intervals, which are further divided into sub-intervals. The amplitude of the column signals during each of the sub-intervals is determined from the desired gray level of the pixel or pixels defined by the corresponding column electrode and selected one or ones of the row electrodes.

Abstract: The present invention includes a projector illumination system having a light source positioned between a condenser lens and a light-collecting reflector. The light source includes a bulb that is urged under compression against a surface of the condenser lens. The condenser lens receives a flow of cooling air over a surface opposite that against which the light source is in contact to minimize deformation of the condenser lens caused by heat emanating from the light source.

Abstract: The present invention includes an invertible and orthoscopic LCD projector having a LCD panel for providing display information that is projected toward a display screen to form a display image. In a preferred embodiment, a converging Fresnel lens is positioned to receive the display information from the LCD panel and form a display object corresponding to the display image. The converging Fresnel lens has an optical center offset from the optical center of the LCD panel in an elevation direction and defines a projection optical axis that extends toward the display screen along an elevation angle in the elevation direction. The Fresnel lens is tilted automatically about a tilt axis transverse to the projection optical axis and the elevation direction by an amount proportional to the elevation angle to cooperate with the offset of the Fresnel lens optical center to form an orthoscopic display image.

Abstract: The present invention includes a matrix display panel assembly (10) having at least two face-to-face matrix display panels (20) that each define an array of pixel components (28) through which light is directed to form a display image. A microlens panel (32, 34) is positioned between the pair of matrix display panels. The microlens panel includes an array of microlenses that receive light propagating through the pixel components of one of the matrix display panels and directs the light through the pixel components of the other matrix display panel. As a result, the panel assembly has improved light transmission capabilities with reduced parallax and depth of field requirements.

Abstract: A method and an apparatus for addressing a liquid crystal display (10) groups together row electrodes (28) and applies the same row addressing signal to all row electrodes in the group (48). The groupings are cyclically changed in successive addressing cycles. An image data conditioner (54) determines for use in calculating the column signals a pixel information value based upon the information values of one or more of the pixels in the selected group of row. Grouping the row electrodes reduces the effective multiplex ratio, thereby increasing the selection ratio and producing a faster responding display having higher contrast and a wider viewing angle.

Abstract: Method and apparatus for providing gray level addressing for passive liquid crystal display (LCD) panels having overlapping row and column electrodes defining pixels are disclosed. Depending upon whether the rows are being addressed by "standard" or "Swift" addressing, the signals for applying to the column electrodes are determined by different calculations, in all of which modes the amplitudes of the column signals are related to the gray level desired to be displayed by the individual pixels. For a split interval system, column signals of appropriate amplitude and polarity are applied during different subintervals of a characteristic time interval of the display panel depending upon the method of addressing the rows. In the full interval mode, the column signals applied over a full time interval are based on the desired gray level of all the pixels in the column, adjusted to provide the proper rms voltage across all the pixels so that they display the desired gray levels.

Abstract: A non-emissive flat panel display, such as an LCD having a plurality of pixels defined by the overlapping areas of row and column electrodes, is provided with a novel mask arrangement to block light from leaking through the interpixel spaces or gaps without electrically shorting the electrodes. The light-blocking mask is split into two parts, with one part deposited on each substrate to block the light from being transmitted through the inter-electrode gaps on the opposite substrate to improve the contrast ratio of the display.

Abstract: A color display is formed by stacking two or more birefringent elements that are tuned to provide different spectral characteristics, and operating each of the elements independently.