Illumination system with compact turning prism and projection system using same

Abstract

In a projection system, an illumination unit directs light to a spatial light modulator, via a prism having first, second and third sides. At least some of the illumination light from the illumination unit enters the prism through the first side, is totally internally reflected at the second side and exits the third side of the prism to the spatial light modulator. The illumination light is incident on the first side along a first axis, the first axis being directed with a component directed towards the spatial light modulator. In some cases, the first prism may introduce prism aberrations to the illumination light. The light from the illumination unit is directed tot the prism by light handling optics. The light handling optics compensate, at least in part, for the prism aberrations.

Dependencies are inferred from the claim text.