| 摘要 |
PROBLEM TO BE SOLVED: To increase the contrast ratio of an optical display system by forming compensation films each giving a desirable angle of retardance for a light valve in the whole objective spectral range. SOLUTION: The system includes at least one compensation film 34 disposed in the optical path between a light valve 18 and a color wheel 14. The reciprocal retardance of the films 34 for the respective components is 180 deg., Since the film 34 compensates the difference in the retardance depending on the wavelength, the retardance of the light valve 18 can be controlled to almost 180 deg. in the whole objective spectra. By this constitution, the light valve is made colorless and decrease in the contrast is hardly caused. The layers of the film 34 consist of a ferroelectric material or other birefringent materials and have the color characteristics selected to compensate the difference in the retardation according to the colors of the light valve 18. |
