| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a direct type surface light source device capable of effectively suppressing luminance irregularity and illuminance irregularity even at relatively large arrangement pitches by a simple structure. <P>SOLUTION: This surface light source device 10 includes: a plurality of linear light sources 11 arranged alone or arranged in parallel with one another to extend in the longitudinal direction; and reflecting surfaces 13 respectively arranged corresponding to the respective linear light sources below them; and is structured such that each reflecting surface 13 comprises, in a cross section vertical to the longitudinal direction of the linear light source, a first ellipsoid E1 (first reflecting surface 21) of which the first focal position is located above the linear light source and the second focal position is positioned substantially in a lateral direction from the first focal position, and a second ellipsoid E2 (second reflecting surface 22) of which the first focal position is located in the vicinity of the linear light source, and the second focal position is positioned substantially in a lateral direction from the first focal position. <P>COPYRIGHT: (C)2008,JPO&INPIT |
