BACKLIGHT APPARATUS

摘要

Backlight apparatus (101) comprising optical waveguide (2) provided with entrance plane (21) having incident region (20) and, opposed to the entrance plane (21), exit plane (22) and comprising a row of light emitting diode elements with multiple light emitting diode elements (1) disposed. The optical waveguide (2) extends to at least first side (90) when viewed from the incident region (20). The optical waveguide (2) has curved surface portion (23) adjacent to second side (91). The curved surface portion (23) is one for receiving light incident on the interior of the optical waveguide (2) from the light emitting diode elements (1) and reflecting the same toward the first side (90). The configuration of cross section of the curved surface portion (23) can be expressed by, on a polar display by r,? using a point of the incident region (20) as an origin, r=exp(-?/tana+C), provided that C is a constant and a a given angle satisfying the relationship 0<A=P/2-SIN<SUP>-1</SUP>(1/n<SUB>0</SUB>) wherein n<SUB>0</SUB> is the reflective index of the optical waveguide (2).