Patent ID: 7204616
Filing Date: 2007-04-17
Classification: G02B

Abstract:
1. A spread illuminating apparatus comprising: at least one light source; a light conductive plate which has the at least one light source disposed toward one end surface thereof introduces light emitted from the at least one light source thereinto through the one end surface, and which allows the light introduced thereinto to exit out from a light exit surface thereof toward an object to be illuminated; and at least one light controlling means disposed between the at least one light source and the light conductive plate, and defining a light entrance surface and a light exit surface, the at least one light controlling means having a refractive index profile formed in both directions parallel to and vertical to the light exit surface of the light conductive plate, wherein the at least one light controlling means is structured such that a plurality of transparent rectangular solids are stacked one over another vertically and horizontally, and that the transparent rectangular solids are put together by means of adhesive which can transmit light emitted from the at least one light source, and wherein the adhesive to put together two adjacent rectangular solids has a refractive index which is at least equal to a refractive index of one of the two adjacent rectangular solids having a smaller refractive index, and which is at most equal to the other one thereof having a larger refractive index.