Patent ID: 8591091

Claim:
A surface light source device, comprising: a generally rectangular light guide plate comprising a plate shaped member having: a first generally planar major surface terminating at an outermost peripheral edge of the light guide plate, a second generally planar major surface opposite the first major surface, a reflective sheet provided at the second generally planar major surface, whereby the first generally planar major surface comprises a light exit surface from which light may be emitted, a side surface extending at least partially from the first generally planar major surface toward the second generally planar major surface, at the outermost peripheral edge of the light guide plate, a recess located between the first generally planar major surface and the second generally planar major surface, the recess extending inwardly from the side surface and into the plate shaped member to provide a light incident surface extending perpendicular to the first generally planar major surface and located inwardly from the side surface, first projections each comprising a first surface at the first generally planar major surface adjacent the outermost peripheral edge of the light guide plate, and a second surface extending parallel to the first surface of the projection and formed by a surface of the recess from the outermost peripheral edge of the light guide plate toward the light incident surface; and a plurality of side view point light sources mounted correspondingly to each said second surface of said first projections and in said recess adjacent to said light incidence surface, whereby light from said side view point light sources entering said light guide plate at said light incident surface will exit said light guide plate at said light exit surface.