Patent ID: 8675150

Claim:
A diffuse lighting device for transmissive liquid crystal screen, comprising: a luminous source of an extended flux of unpolarized light that comprises: a diffusing layer exhibiting a high albedo of at least greater than 0.3, on a light emission surface of said luminous source, and a stack of a quarter-wave plate and of a reflecting polarizer, wherein said stack is disposed on the luminous source, with at least one quarter-wave plate in said stack being arranged between the reflecting polarizer and the diffusing layer exhibiting the high albedo of the luminous source, wherein said reflecting polarizer is arranged such that light which does not cross said reflecting polarizer is at least in part reflected via said stacked quarter-wave plate toward said diffusing layer exhibiting the high albedo, and wherein the diffusing layer diffuses light back towards the reflecting polarizer via said stacked quarter-wave plate.