Patent ID: 7242536
Filing Date: 2007-07-10
Classification: G02B,G03B

Abstract:
1. A Fresnel optical element having a plurality of Fresnel prisms arranged on a surface of a base and in a sawtooth shape, each of said plurality of Fresnel prisms having a refractive surface for refracting an incident light ray emitted from a light emitting body and a reflective surface for reflecting the light ray refracted by said refractive surface, wherein the refractive surface of each of said plurality of Fresnel prisms includes a non-light incidence surface upon which any light ray emitted from said light emitting body is not directly incident because it is intercepted by another one of said plurality of Fresnel prisms, the non-light incidence surface having an angle with said reflective surface which is different from a prism apex angle which said refractive surface forms with said reflective surface.