Patent ID: 7695182

Claim:
A planar lighting device comprising: a light source for emitting light; a light guide plate disposed adjacent to the light source and including a light entrance plane for admitting the light emitted by the light source and a light exit plane for emitting the light admitted from the light entrance plane as planar light; a support member for supporting the light source and the light guide plate while keeping constant a distance between the light source and the light entrance plane of the light guide plate; a housing for housing the light source and the light guide plate supported by the support member; a sliding mechanism disposed between the housing and the support member for elastically sliding the support member with respect to the housing in a direction from the light entrance plane of the light guide plate to the light source according to expansion/contraction of the light guide plate while keeping constant the distance between the light source and the light entrance plane of the light guide plate; and a reinforcing member for reinforcing the housing according to the expansion/contraction of the light guide plate.