Patent ID: 7061677
Filing Date: 2006-06-13
Classification: G02B,G03B

Abstract:
1. A screen for a projection display, the screen comprising: a Fresnel lens sheet operable to converge light emitted from a light source; and a lenticular lens sheet operable to disperse in a horizontal direction the light transmitted by the Fresnel lens sheet, wherein the Fresnel lens sheet comprises a first Fresnel lens on one surface and a second Fresnel lens on an opposite surfaces, wherein the first Fresnel lens comprises a plurality of Fresnel lens units, each of the plurality of Fresnel lens units comprises a first Fresnel lens surface and a second Fresnel lens surface, wherein a first angle of the first Fresnel lens surface with respect to a central line between the first and second Fresnel lens surfaces, and a second angle of the second Fresnel lens surface with respect to the central line, are changed depending on incident angles of the light, and wherein the first angle has a range of where θ 1 is the first angle and α 1 is a first incident angle of the light with respect to a normal line of the screen.