05633755 is referenced by 53 patents.
A projection apparatus is disclosed that can be used for projection TV and related applications. The apparatus comprises a light source, a projection optical system, a DMD with multiple micromirrors, and a controller for individually controlling the tilt of the micromirrors. The projection optical system comprises, in order from the DMD side, a first lens group, an aperture stop, and a second lens group. An illumination stop is situated between the first and second lens groups. Light from the light source passes through the illumination stop and the first lens group to impinge on the DMD. The controller coordinatedly controls the tilt of the micromirrors in the DMD so that the impinging light is selectively reflected to one or the other of the aperture stop and the illumination stop, thereby eliminating ghost-forming reflections of light not projected onto a screen.