Patent ID: 6986600
Filing Date: 2006-01-17
Classification: B60Q,G01D,G02B

Abstract:
1. A lighting device comprising a light source; a light conducting plate having an incident surface receiving light emitted from the light source, a back surface and a light-emitting surface; and a reflection member having a first portion facing the back surface, and a second portion located on a side opposite a side of the light conducting plate on which the light source is located, the light conducting plate comprising a plurality of concave portions which include grooves and are formed on the back surface and orient light emitted from the light conducting plate via the back surface toward an emission surface of the lighting device wherein a parameter related to the plurality of concave portions is weighted so that an even luminance distribution can be obtained on the emission surface, and the plurality of concave portions are arranged with a first pitch in a center portion of the back surface, and are arranged with a second pitch in an end portion of the back surface.