Patent ID: 7712908

Claim:
A light-transmitting film comprising: a light incident surface; and a light emission surface constituted of a structure surface on which prisms are continuously disposed, wherein the light-transmitting film is constituted of a single layer, and wherein each of the prisms has an index of refraction in an extension direction of the prisms and an index of refraction an alignment direction of the prisms which are different from each other, and each of the prisms includes a pair of inclined surfaces that, regarding partial light incident on the light incident surface from an oblique direction, reflect to the light incident surface side a polarization component in one of the extension direction of the prisms and the alignment direction of the prisms that has a larger index of refraction while causing a polarization component in another one of the extension direction of the prisms and the alignment direction of the prisms that has a smaller index of refraction to transmit therethrough, and reflect light incident on the light incident surface from a vertical direction to the light incident surface side regardless of a polarization state.