Illumination system and projection system incorporating same

Abstract

An illumination system and a projection system incorporating same are disclosed. The illumination system includes a two-dimensional array of independently operable light sources. Each light source illuminates substantially the entire active area of a pixelated optical light modulator. Each light source emits light in different emission directions. Each emission direction is directed to a respective location in the active area. Each pixel in the active area is illuminated by an incident cone of light from the two-dimensional array of independently operable light sources. The cone has a cone angle and includes at least one light ray from each light source. The cone angle of at least one such cone of light can be controlled by adjusting the intensity of one or more of the independently operable light sources.

1 . An illumination system for a projection display comprising:
 a two-dimensional array of independently operable light elements centered on an optical axis; and   a first optical transfer system centered on the optical axis for receiving light from the light elements and illuminating an active area of a pixelated light modulator, the active area being capable of displaying a projectable image, wherein light from at least one light element illuminates the active area from a finite number of directions, the finite number of directions being rotationally symmetric about the optical axis, and wherein each pixel in the active area is capable of being illuminated by each light element, a contrast ratio of the projectable image being controllable by adjusting an output intensity of one or more light elements.