Patent ID: 7940350
Filing Date: 2011-05-10
Classification: F21V,G02F

Abstract:
1. A plane light source having a plurality of light emitting devices arranged in a light emitting device matrix having rows and columns at a substrate, the plane light source comprising: a first matrix having a plurality of light emitting devices arranged in rows and columns; and a second matrix having a plurality of light emitting devices arranged in rows and columns, each of the light emitting devices located within a quadrangle formed by four neighboring light emitting devices included in the first matrix, wherein a pitch S between one light emitting device included in the light emitting device matrix and another light emitting device most adjacent to the one light emitting device satisfies the following equation to obtain uniform luminance distribution at a position on a diffusion sheet, the position distant from a light emitting surface of the light emitting device by an optical length l, where −π/18≦α≦π/18 is satisfied, and θ is an orientation angle of the light emitting device.