Portable image projection system having reduced weight and profile

Abstract

An image projector employs a prism assembly that receives incident light, illuminates a reflective light modulator, and receives therefrom reflected imaging light for direction toward a small-diameter light entry pupil of a light-weight, compact projection lens. The prism assembly includes compensating and output prism components having opposed surfaces separated by an air gap. The prism assembly sets up a correct illumination angle on the DMD and then separates the incident illumination light from the reflected imaging light. Each on-state micromechanical DMD mirror reflects the illumination light nearly normal to a horizontal datum plane, forming reflected imaging light that reflects off the air gap and reenters the prism assembly through the output prism component. A focusing lens disposed between the prism assembly and the DMD refracts the reflected imaging light into a converging imaging light bundle compatible with the small diameter light entry pupil of the projection lens.

Dependencies are inferred from the claim text.