Patent ID: 6064452
Filing Date: 2000-05-16
Classification: G02B,G02F,H04N

Abstract:
A single plate type color liquid crystal display apparatus having light source means, collimator means, and single plate type liquid crystal panel means, comprising:light diffracting means arranged between said collimator means and said single plate liquid crystal panel means; andthree-position means,wherein said light diffracting means is, at a macroscopic level, in a three-dimensional unflat plate form with a macro periodic structural pitch and additionally has at least either a macro-prism shape or a stepped lenticular shape, and also includes a multi-stepped diffraction gratings at a microscopic level, wherein the input white light is, when it becomes a diffraction output, decomposed into three primary color rays traveling in three different directions, wherein a separation angle .omega. between a red ray and a green ray in said three primary color rays is larger than 0.05 rad, wherein about L (L is an integer out of 1, 2 and 3) times a specific optical wavelength .lambda..sub.0 is selected for at least the principal ray an effective unit optical path difference at a unit step of said multi-stepped diffraction grating, wherein an array pitch projection P of said unit step in the direction at right angles with an advancing direction of said green output ray is arranged so as to be substantially equal to a value obtained by dividing about L times a red-green wavelength difference (about 80 nm) by said red-green separation angle .omega., more specifically, 80L nm/.omega., and wherein said three primary color rays as diffraction output, traveling in three different directions are converged to specified three color positions.