Patent ID: 6603520
Filing Date: 2003-08-05
Classification: G02B

Abstract:
An optical film comprising:a transparent film with a refractive index of not lower than 1.49, said transparent film including light exit means, which are constituted by concave or convex portions arranged in one surface of said transparent film so as to face a virtual center located on or outside a side surface of said transparent film, which serves as a light source arrangement side each of said concave or convex portions having a length of not larger than 200 &mgr;m and a depth or height of not larger than 50 &mgr;m, each of said light exit means having an optical path changing slope inclined to said one surface of said transparent film at an inclination angle in a range of from 35 to 48 degrees, and an elevational face inclined to said one surface at an inclination angle of not lower than 50 degrees.