| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a planar light source device with luminance unevenness eliminated even if an arrangement distance between LED light sources and an optical sheet is shortened or an arrangement distance of the LED light sources are widened in a downright type backlight with a plurality of the LED light sources arranged. <P>SOLUTION: The planar light source device is provided with a plurality of LED light sources arranged on a reflection sheet and an optical sheet structure having: one or more optical sheets with a light diffusion agent and a concavo-convex shape formed thereon, having a total light transmittance of 40%-70% when an opposite side face to a face having a concavo-convex shape is made a light incident surface and moreover a total light transmittance of 80% or more when the face having the concavo-convex shape is made a light incident surface; and an optical sheet having a total light transmittance of 55-70% even if either of a front face or a rear face is made a light incident surface, and superimposed on a light emitting surface of the former optical sheet. <P>COPYRIGHT: (C)2012,JPO&INPIT |
