| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress abnormal light emission in the vicinity of the incidence face of a light guide plate, and make hard to be visibly observed a boundary position in which the groove depth of a prism groove of the light guide plate changes. <P>SOLUTION: On the rear face 4 of the light guide plate 2, the prism grooves 12 extended and installed toward a direction away from the incident face 5 are formed along the incident face 5 numerously and in parallel. The prism groove 12 is composed of a first prism groove part 12A with an approximately constant groove depth extended and installed toward the direction away from the vicinity position P of the incident face 5, and a second prism groove part 12B which extends toward the incident face 5 continuously from the vicinity position P which is one end of the first prism groove part 12A, and in which the groove depth decreases gradually as it comes closer to the incident face 5. Then, vicinity positions P each of which is a boundary position between the first prism groove part 12A and the second prism groove part 12B are formed of numerous prism grooves 12 differently at random. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
