Patent ID: 6069738
Filing Date: 2000-05-30
Classification: G02B,G03F

Abstract:
An image projecting system comprising:a source of light;a projection surface;a light encoder between the light source and the projection surface; andan extended depth of field (EDF) mask between the light source and the projection surface;wherein the EDF mask is constructed and arranged to cause variations in a wavefront of light passing through the mask, wherein the variations in the wavefront result in an altered optical transfer function of the image projection system that is substantially less sensitive to the distance between the light encoder and the projection surface than the optical transfer function of the image projection system without the EDF mask; andwherein the light encoder encodes the light with information related to a desired image and to account for variations introduced by the EDF mask, such that the light passing through the EDF mask and the light encoder forms the desired image at the projection surface.