| 摘要 |
PROBLEM TO BE SOLVED: To provide a color system utilizing a diffraction grating which is bright because the utilization efficiency is extremely high and has satisfactory color balance of three-primary colors and is capable of being constituted with parts in which optical system are a few and is of relatively compact and is of inexpensive, and a liquid crystal display device. SOLUTION: This filter system is constituted of a diffraction grating 11 almost perpendicularily arranged in a roughly parallel luminous flux 12 and which is consisting of interference fringes or gratings having parallel and uniform pitches, a convergent lens array 10 arranged by being inclined with respect to the surface of the diffraction grating 11 at the side of the grating and a liquid crystal display element 1 whose pixel surface is arranged in the vicinity of the focal surface of the array 10. Then, a red wavelength component 12R, a green wavelength component 12G and a blue wavelength component 12B whose wavelengths are dispersed in the diffraction grating 11 and which are converged on different positions by respective elemental lenses 10' of the array 10 are respectively made incident on a pixel R which is to display red of the liquid crystal display element 1, on a pixel G which is to display green of the element 1 and on a pixel B which is to display blue of the element 1. |
