Patent US 4,076,384

The rear-projection viewing screen receives light incident upon its back side from the objective of a rear-projection projector and forms a corresponding image visible to a human eye viewing the front side of the viewing screen. The viewing screen is comprised of a lens-aperture matrix and an optical system cooperating with the lens-aperture matrix. The optical system serves the function of a lens matrix comprised of lens-matrix elements which focus the light from the objective of the rear-projection projector through the apertures of the lens-aperture matrix. The optical system furthermore serves the function of a field lens operative for gathering the light emanating from the objective of the projector and deflecting such light in direction toward the optical axis of the objective so as to increase the amount of light from the marginal portions of the viewing screen reaching a viewer's eye located on such optical axis.