| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a surface light source device in which uniform illumination free of unevenness can be performed irrespective of positions for observing a screen. <P>SOLUTION: The light source device is equipped with light emitting tubes 13 arrayed at equal intervals with spaces L, and a uniformization sheet 14 which uniformizes the light emitted from the light emitting tubes 13 by diffusion. When the transmittance of the light made incident on the uniformization sheet 14 from a normal direction of the sheet is defined as T, the relations of the vertical transmittance T, the spaces of the light emitting tubes 13, and the distance D between the light emitting tubes 13 and the uniformization sheet 14 are so set as to satisfy the relations 0.8T≤0.7×2×cos<SP>2</SP>(tan<SP>-1</SP>(L/2D))-0.8×2×cos<SP>2</SP>(tan<SP>-1</SP>(L/D))≤1.2T. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
