DIFFRACTION-REFRACTION TYPE OPTICAL ELEMENT AND LIQUID CRYSTAL PROJECTOR

摘要

PROBLEM TO BE SOLVED: To increase the proportion of light emitting area of a liquid crystal panel by using an optical element having functions to diffract light beams emergent from filters and to make the diffracted light beams parallel again, although the liquid crystal panel transmits light only through the filter opening but not through the black strips. SOLUTION: Light beams of a color image emergent from the color filter parts of a liquid crystal panel equipped with black stripe parts 7 are diffracted with a diffraction grating 8 to make the black stripes invisible. The directions of the diffracted light beams are then made to coincide with the direction parallel to the incident light by refraction. The mixing of light beams emergent from adjacent filters is prevented and an unblurred image free from the shadows of the black stripes 7 is given.