| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent variations in luminance of emitted light by preventing burrs causing abnormal light emission from being produced. <P>SOLUTION: A light guide plate 3 is divided into a rod-like first light guide part 13 and a plate-like second light guide part 14 by an upper groove 11 and a lower groove 12 each having bottoms, and the upper groove 11 and the lower groove 12 are formed almost perpendicularly to a pair of the facing side faces 4, 8 of a plate-like body having an almost quadrangular plane so as not to interfere each other. The upper groove 11 and the lower groove 12 do not pass through the light guide plate 3 in its thickness direction, and the bottoms of the grooves 11a, 12a are brought in line with each other in the thickness direction of the light guide plate or are overlapped in the thickness direction. The upper groove 11 and the lower groove 12 continuously extend to the vicinity of a pair of the side faces 4, 8. A plurality of first prism-like protrusions 21 to deflect light from a point-like light source 5 so as to advance almost along the normal direction of first light emitting surfaces 11b, 12b are formed in the first light guide part 13. Light which has passed through the upper groove 11 or the lower groove 12 to enter the second light guide part 14 is deflected so as to advance almost along the normal direction of a second light emitting surface 17. <P>COPYRIGHT: (C)2010,JPO&INPIT |
