Patent ID: 8100549
Filing Date: 2012-01-24
Classification: G02B,G02F,H01L,Y10S

Abstract:
1. A surface light source, comprising: a plurality of lighting devices arranged in a plane, each lighting device, comprising: a light emitting diode for emitting light; and an illuminating lens for spreading light emitted from the light emitting diode so that a surface to be irradiated is irradiated with the spread light, the illuminating lens including: wherein the lighting device satisfies the following inequality: where D is a maximum width of a light emitting surface of the light emitting diode, and t is a center thickness of the illuminating lens; and a diffusing plate disposed to cover the plurality of lighting devices, the diffusing plate configured to receive on one surface thereof light emitted from the plurality of lighting devices to emit the light from an other surface thereof in a diffused manner, wherein the surface light source satisfies the following inequality: where D is the maximum width of the light emitting surface of the light emitting diode, and h is a distance from a light emitting surface of the light emitting diode in each of the lighting devices to the one surface of the diffusing plate.