| 摘要 |
<P>PROBLEM TO BE SOLVED: To enable to input relatively large power to a semiconductor light emitting element and control rise of a junction temperature of the semiconductor light emitting element with constraint of applicable environment minimized. <P>SOLUTION: The planar light source A is provided with a plurality of light-emitting diodes 11 mounted on a substrate 12, a substrate holder 13 holding the substrate 12 and thermally-coupled with the substrate 12, a light guide plate 20 having an incident face 20a or a circumferential face, where light from the light emitting diodes 11 enters and a light emitting face 20b or a face crossing the circumferential face, and a back plate 30 made of a metal plate, arranged opposed to a rear face of the light emitting face 20b on the light guide plate 20. The substrate holder 13 is provided with a back piece 13c superimposing and thermally-coupling with one end part of one face in a thickness direction of the back plate 30. <P>COPYRIGHT: (C)2010,JPO&INPIT |
