Abstract: An image display device incorporating a specialized phase expansion circuit, a rotation circuit, a sampling device and unique controlling circuitry. The phase expansion circuit includes a plurality of trail buffers or sample holder circuits for receiving a serially applied train of pixel image signals, expanding or extending the assertion cycle time and generating a corresponding plurality of expanded image signal trains in parallel. Preferably, one combination of expanded pixel image signals corresponding to specific position of pixels arranged in matrix in one train is different from another combination of expanded pixel image signals. The rotational circuit includes a plurality of selecting circuits for receiving the manifold trains of expanded pixel image signals generated by the phase expansion circuit.

Abstract: A projection-type display apparatus in which the entry of light rays to the back side of liquid crystal light valves from dichroic prism that composes optical system light synthesizer is prevented. To this end, a projection display according to the present invention preferably includes a color synthesizer for combining colored and modulated light beams, comprising: a square column dichroic prism composed of four triangle prisms having equal refractive index together whose cross sections are right isosceles triangles such that three light valves are located adjacent to three exterior peripheral surfaces of dichroic prism to receive colored and modulated light beams therefrom and; a filter for absorbing light with a specified wavelength range, leaked from surface of dichroic prism at the opposite side of incident light surface and directed to liquid crystal light valve, the filter being located between liquid crystal light valves and surface of dichroic prism.

Abstract: A projection-type video display in which the entire input video signal is first digitally corrected through digital gamma correction. Then, a subset of the corrected video signal is corrected again through analogue correction techniques. In particular this portion of the digitally corrected video signal corresponds to the subject where slopes of applied voltage-transmissivity characteristic curve (V-T curve) of liquid crystal changes relatively rapidly. The result is a more accurate gamma correction which is also less expensive than conventional, purely digital gamma correction systems.

Abstract: A projection display comprising: a square column dichroic prism composed of four triangle prisms having equal refractive index together whose cross sections are right isosceles triangles such that three light valves are located adjacent to three exterior peripheral surfaces of dichroic prism to receive colored and modulated light beams therefrom and; a filter for absorbing light with a specified wavelength range, leaked from surface of dichroic prism at the opposite side of incident light surface and directed to liquid crystal light valve, the filter being located between liquid crystal light valves and surface of dichroic prism. As for construction of the dichroic prism itself, specifically, of the four aforementioned triangular prisms, the first triangular prism and the aforementioned third triangular prism are mutually affixed in a condition in which there is a first step difference in the vertical direction. The first exposed side is formed on one edge of the affixed side of the first triangular prism.