| 摘要 |
A light pipe has a transparent resin plate having an average in-plane retardation of not larger than 20 nm, a transparent film having an average in-plane retardation of not larger than 20 nm, and an adhesive layer having a refractive index different by 0.1 or less from that of the transparent film. The transparent film is bonded to the transparent resin plate through the adhesive layer and wherein in the transparent film includes a repetitive prismatic structure constituted by optical path control slopes which are disposed on an outer surface of the transparent film and which are aligned in a substantially predetermined direction so that each of the optical path control slopes is inclined at an inclination angle in a range of from 35 to 48 degrees with respect to a film plane.
|
