Patent ID: 8334950
Filing Date: 2012-12-18
Classification: G02B,G02F

Abstract:
1. An illumination apparatus, comprising: a polarization plate; a light source; a diffusion sheet; a reflection-type polarization separation element; and a light transmission film that is disposed between the polarization plate and the diffusion sheet and includes a plurality of prisms formed on a surface thereof, the plurality of prisms each having a ridge line in a first direction and being continuously arranged in a second direction perpendicular to the first direction, wherein the light transmission film is disposed such that a ridge line direction of the plurality of prisms is one of a perpendicular direction and an approximately perpendicular direction to a transmission axis of the polarization plate, wherein the ridge line direction is parallel to an edge of the illumination apparatus, wherein the reflection-type polarization separation element is disposed between the polarization plate and the light transmission film and is configured to transmit a first linear polarization component and reflect a second linear polarization component, wherein the light transmission film is disposed such that the ridge line direction of the plurality of prisms is one of a perpendicular direction and an a approximately perpendicular direction to a transmission axis of the reflection-type polarization separation element, and wherein the reflection-type polarization separation element has a multilayer structure in which layers having different refractive indexes are alternately laminated.