Patent ID: 8303152

Claim:
A spread illuminating apparatus comprising: a light guide plate comprising a plurality of protrusions disposed along a side surface thereof such that a plurality of interspaces are formed with each interspace being located between two adjacent protrusions; and a plurality of point light sources which are disposed in two rows respectively at the interspaces and the protrusions and which each comprise a light emitting element chip, and a lamp house made of a reflective material and having a recess for storing the light emitting element chip at a center part thereof, wherein the protrusions each integrally comprise: a proximal portion which extends from the side surface and which has a substantially constant width; and a distal portion which extends further from the proximal portion and which has a width increasing in accordance with an increase in distance from the proximal portion, and wherein the distal portion of the protrusion has, at its top end surface, a width which is larger than a width of an opening area of the recess and also smaller than an overall width of the lamp house where the widths of the proximal and distal portions of the protrusion, the width of the opening area of the recess and the overall width of the lamp house are dimensions along a longitudinal direction of the side surface of the light guide plate.