Abstract: A method of modifying the polarization state of light exiting a Liquid Crystal Display that is effected without altering the optical image of the display comprises reducing the select voltage to the LCD cell to less than the saturation select voltage. In one embodiment of an apparatus incorporating features of the present invention, a color LCD display is constructed using two or more LCD cells that are aligned to produce an optimum image through the display optics. One or more of the LCD cells are then driven to the dark state at a select voltage that is less than the saturation select voltage for that cell. By operating the LCD cell at less than the saturation select voltage, the polarization state of the light exiting a dark selected pixel compensates for the misalignment between the saturation voltage polarization axis of the display and the system polarization axis of the optics. Accordingly, the selected pixel appears darker than would the same pixel driven at the saturation voltage.

Abstract: An optical docking station comprises an optical frame and a detachable virtual image display module. The display module comprises a low power light source such as a light emitting diode, one or more beam splitters, polarizers, a liquid crystal display panel and an imaging lens. When the display module is detached from the optical frame, the light emitting diode provides the primary illumination for the image formed by the liquid crystal display panel. The image thus formed is a magnified virtual image of the liquid crystal display panel. When the display module is attached to the projector frame, however, a more powerful light source mounted to the optical frame provides the primary illumination. The more powerful light source forms a real image of the liquid crystal display module, which is capable of being projected onto a screen.

Abstract: A contrast enhancement filter for color displays, particularly adapted for color CRT tubes of the shadow mask type. A transparent plate has applied thereon absorptive areas, each area dyed with a primary color corresponding to the color dots of the CRT display face and a plurality of such color areas randomly disposed over each color dot. Since the absorption areas are spacially independent, each color area acts independently of the others. The filter provides bandpass efficiency comparable to monochrome filters, and has a broad viewing range essentially independent of angle of vision. In a further embodiment, colored oriented fiber-optic elements are disposed over the phosphor dots in a predetermined array, allowing the filter plate to replace a conventional faceplate and filter combination structure, while providing a selective viewing angle of high contrast. The filter is suitable for any light-responsive display screen, also including liquid crystal elements.

Abstract: A gaseous glow discharge display tube having a plurality of digits positioned within a common envelope is filled with a gas mixture of such a composition so as to reduce the blanking requirements for streamer elimination. Within a prescribed range of current densities, and applied voltage, blanking requirements may be entirely elininated.