Optical system for a colour picture display.

摘要

There is disclosed an optical system for a color picture display having three spatial light modulators of reflecting type corresponding to an optical image of one of three primary colors by photoelectric effect and photomodulation effect, a writing device for guiding writing lights each carrying the optical image of one of the colors to each device, a reading device for guiding reading lights each in the region of wavelength of one of the colors to each device and a composing device for composing a composed reading light of the reading lights which are emitted from the optical devices respectively after optically modulated. The optical system comprises an optical apparatus (SCA) shared by the reading device and the composing device, having first, second and third prisms (1, 2 and 3), a first dichroic filter (4) provided between the first and the second prisms (1 and 2) and a second dichroic filter (5) provided between the second and the third prisms (2 and 3).