Patent ID: 9022635
Filing Date: 2015-05-05
Classification: G02B

Abstract:
1. A backlight unit comprising: a light guide plate; a light source disposed on one side of the light guide plate; and a reflective plate disposed under the light guide plate, wherein the light guide plate comprises a plurality of unit slits comprising a first slit and a second slit, wherein, in the cross section of one side of the unit slit, the first slit and the second slit are inclined from a top surface of the light guide plate toward an inside of the light guide plate with respect to a vertical direction of the top surface, wherein the first slit and the second slit are symmetrical to each other with respect to the middle portion of each unit slit, and wherein each unit slit is configured such that when light is incident on one of the first slit and the second slit, the light is totally reflected by the one of the first slit and the second slit, and the totally reflected light is emitted from the light guide plate in a perpendicular direction with respect to the top surface.