| 摘要 |
PROBLEM TO BE SOLVED: To give a divergence effect and prevent brightness non-uniformity generated when a reflection index is improved by employing a reflection process to be applied to an back face side of a light guide plate as a linear reflection cut along an axis of a fluorescent lamp and employing one surface of a divergence plate as a rugged face parallel to the axis of the fluorescent lamp. SOLUTION: A reflection process 3 to be applied to a back face 2a side of a light guide plate 2 made of crystal resin is cut in a reverse V-letter shape and employed as a reflection cut 3a. The reflection cut 3a is linear along the axis of a fluorescent lamp 4, an interval of the cut 3a is narrowed as it is distant from an end face 2b, and an illumination distance generated is corrected by means of the distance from the lamp 4. One surface of a divergence plate 5 forms the rugged face 5a parallel to the axis of the lamp 4. A light that reaches from the lamp 4 to the reflection cut 3a, substantially all of which is reflected, is directed to an irradiation face 2c side, however, external radiation reflected on the inner face by means of the rugged face 5a of the divergence plate is generated, and brightness non-uniformity is eliminated. |
