PROJECTION TYPE LIQUID CRYSTAL DISPLAY DEVICE

摘要

PURPOSE:To eliminate the adhesion of dust to optical parts and to lessen the degradation in brightness and the degradation in contrast ratio by decreasing the reflection of the light generated at the boundaries of the optical parts and further absorbing the light of the colors unnecessary for projection thereby improving the contrast ratio of a liquid crystal projector and improving the color purity of reproduced image CONSTITUTION:A medium colored with dyes which absorb a part of a transmitted light region is provided between reflection type liquid crystal panels 11 to 13 and a dichroic prism 8 and a non-colored medium is also provided between a projection lens 3 and the dichroic prism 8. Since the optical parts can be held hermetic by the media, the adhesion of the dust to the optical parts by a cooling fan 19 is obviated.