Patent ID: 7784978
Filing Date: 2010-08-31
Classification: G02B,G02F

Abstract:
1. A surface light source device comprising: a circuit board including at least one conductive pattern thereon; a plurality of line light sources positioned substantially parallel with respect to each other and located adjacent the circuit board and the conductive pattern, each of the light sources configured to emit light along a light emitting axis that is substantially perpendicular to the circuit board; and a light guide including a top surface and a bottom surface, the plurality of line light sources located closer to the bottom surface than the top surface and between the light guide and the circuit board, the top surface of the light guide including a plurality of two-dimensional curved surfaces configured to each have a base line comprised of portions that are closest to the circuit board as compared to other portions of each respective two-dimensional curved surface, each base line extending substantially parallel with a respective one of the plurality of line light sources and intersecting with the light emitting axis of the respective one of the plurality of line light sources, and each of the base lines being connected to a surface of the plurality of two-dimensional curved surfaces which curves upwards and away from each respective base line, the bottom surface of the light guide being configured to receive light emitted from each of the plurality of line light sources, wherein the plurality of two-dimensional curved surfaces are configured to totally reflect light directly incident on the plurality of two-dimensional curved surfaces from each of the plurality of line light sources.