Patent ID: 6250763
Filing Date: 2001-06-26
Classification: G02B,H04N

Abstract:
A projection device comprising a light source, a plurality of reflective spatial light modulators, and a prism system arranged in the light path between the light source and the spatial light modulators, the prism system including at least one totally internally reflecting surface for light incident on the surface at greater than a critical angle, the surface being arranged to direct light from the light source onto a dichroic surface, focusing means in the light path between the light source and the prism system such that the light beam incident on the dichroic surface has a spread of angles relative to the optical axis effective to focus the light produced by the light source to produce a focused beam on each spatial light modulator, the dichroic surface being arranged at an angle to the normal to the optical axis substantially equal to said spread of angles, the dichroic surface being arranged to reflect a portion of the light incident on the dichroic surface onto at least one of the spatial light modulators.