ILLUMINATING DEVICE, DISPLAY DEVICE, AND PORTABLE ELECTRONIC DEVICE

摘要

An illuminating device comprises: a light emitting element made of a light emitting diode; and a light guide plate with a light receiving section installed on a side surface wherein the light receiving section is opposite to the light emitting element. The light guide plate emits illuminating light from a first surface. The light receiving section has a plurality of cylindrical lens surfaces formed therein. Each of the cylindrical lens surfaces is formed of a concave curved surface wherein an axial direction of the curved surface is parallel to a thickness direction of the light guide plate. The cylindrical lens surfaces are formed in a direction orthogonal to the axial direction. Each of the cylindrical lens surfaces is formed of an arcuate surface having a curvature radius of 0.5 mm or less, and more preferably 0.2 mm or less.