Patent ID: 6154259
Filing Date: 2000-11-28
Classification: H04N

Abstract:
A laser projection system for projecting an image with reduced speckle on a display surface, comprising:a light modulator for modulating laser light responsive to signals indicative of said image;an optical system that defines an intermediate image plane for said modulated laser light, said intermediate image plane situated between said light modulator and the display surface;a speckle eliminator situated approximately at said intermediate image plane and comprising a diffusion plate, motion-inducing elements coupled to said diffusion plate and arranged approximately orthogonally with respect to said diffusion plate and means for energizing said motion-inducing elements to provide a non-zero phase shift between the motions of said orthogonal elements, thereby avoiding periodic moments of zero velocity; andan optical imaging system arranged to image said intermediate image plane and project diffused modulated laser light from said speckle eliminator on the display surface to display an image.