SURFACE LIGHT SOURCE DEVICE, AND BACKLIGHT UNIT INCLUDING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a surface light source device enabling a module to be slimmed and be reduced in cost, and to provide a backlight unit including the same.SOLUTION: A surface light source device is provided with: a light guide plate having a light-incident face into which light from light sources arranged along a prescribed axis enters, an emission face from which the incident light is emitted, and a rear face opposed to the emission face, and having a lenticular pattern is formed on the emission face and a plurality of unit cells having microprism patterns discretely formed on the rear face, a vertex angle (&thetas;) of the unit prism of the microprism pattern being 80° or more and 83° or less and an arrangement direction of the unit prisms being parallel to an arrangement direction of the light source; and a microprism sheet laminated on an upper part of the light guide plate and provided with prisms of which a vertex angle (&thetas;) is 90° or more and 110° or less.