SURFACE LIGHT SOURCE DEVICE HAVING HIGH BRIGHTNESS

摘要

PURPOSE: A surface light source device is provided to make an amount of insertion of one side in a surface light source converter longer than a gap between other side of the surface light source converter and a frame, thereby realizing a uniform surface light source device with high brightness without the converter being fallen from a reflector. CONSTITUTION: An optical incident surface(26a) of a light guide plate(26) is inserted between an upper portion(31a) and a lower portion(31b) of a lamp reflector(31) for covering a cold cathode tube(22). A reflective sheet(29) is fixed to a surface of a frame(32) via an electric insulating tape(41). The light guide plate(26) is installed on a surface of the reflective sheet(29). An amount of insertion(A) between the upper section(31a) and the lower section(31b) is set to be bigger than a gap(B) between a non-optical incident surface(26d) of the light guide plate(26) and a step difference portion(35) of the frame(32).