| 摘要 |
PROBLEM TO BE SOLVED: To make light outgoing from the center part of an emission surface of a light guide plate, brighter than light outgoing from the other parts. SOLUTION: A plurality of LEDs 4a-4d are arranged along at least one side face 3 of a light guide plate 2. The light from a plurality of LEDs 4a-4d is propagated inside the light guide plate 2 after entering the light guide plate 2, and the light whose incident angle to the emission surface 12 becomes a critical angle or less in the process of propagation is emitted from the emission surface 12. The side faces facing the LEDs 4a, 4d arranged on both end sides of the light guide plate 2, out of a plurality of LEDs 4a-4d, are formed in approximately semicircular curved faces 7 formed to surround the light emitting parts 5a-5c of the LEDs 4a-4d. The side faces facing the LEDs 4b, 4c arranged between the LEDs 4a, 4d on both end sides of the light guide plate 2 is formed in a plane 10 extending in an almost orthogonal direction to the plate thickness direction of the light guide plate 2. |
