Patent ID: 7271955

Claim:
A transmission screen comprising: a Fresnel lens sheet having a front surface facing the viewer and Fresnel lens elements formed on the front surface, and a shading sheet placed contiguously with the front surface of the Fresnel lens sheet; wherein the shading sheet is provided with shading elements for absorbing external light fallen on the front surface of the shading sheet from a viewer side, wherein the shading elements transmit external light fallen on the shading sheet at an incident angle θ meeting Expression (1) and penetrated into and diffracted by the shading sheet θ<24+0.018 ×F (1) where θ is incident angle of external light that falls on the shading sheet and F is the focal length of the Fresnel lens elements in millimeter, and wherein the shading sheet has a rib group including a plurality of ribs extending in a direction and the shading elements, wherein each of the shading elements has a total-reflection facet contiguous with the rib and capable of reflecting in a total reflection mode the external light fallen on the front surface of the shading sheet from the viewer side toward the projection light source, and the shading elements are light-absorbing parts containing a light-absorbing material.