TWO LAMP, SINGLE LIGHT VALVE PROJECTION SYSTEM

摘要

A projection system includes first and second light sources which are disposed at an angle with respect to each other and are activated during respective different phases of an illumination cycle to illuminate a spot on different sides of a segmented rotary filter wheel. The filter wheel is alternately used to transmit light from one of the light sources, and to reflect light from the other light source, to a light valve, the output of which is projected onto a screen. The wheel segments may be alternately clear and mirrored or may alternately transmit and reflect colors to produce color sequential illumination of the light valve. In addition to filter wheels producing sequences of red, blue, green illumination, including the possibility of splitting a color phase into non-adjacent smaller phases to reduce color artifacts, a simple filter wheel which in two rotations produces a sequence of red, blue, green, cyan, magenta, yellow color illumination, resulting in an expanded color gamut, is also disclosed. Blanking intervals during which both lamps are turned off span each passage of a segment boundary through the spot.