| 摘要 |
PROBLEM TO BE SOLVED: To obtain an inexpensive narrow-frame surface light source device which is easily produced by making an angle formed by the light entering surface and the light exiting surface of a light transmission body almost equal to an angle formed by the light entering surface and the back surface thereof. SOLUTION: Luminous flux generated by a bar-like light source lamp 12 is made incident from the end face of the plate-like light transmission body 11 and emitted from the surface of the body 11 while it is propagated in the body 11. The cross section of the body 11 is wedged by the light exiting surface 11b and the back surface facing to the surface 11b at some inclination. The end face on a wide side in the case of viewing from the wedged cross section of the body 11 is set as the light entering surface 11a and made adjacent to the lamp 12, and the angle formed by the surface 11a and the surface 11b is made equal to the angle formed by the surface 11a and the back surface. A light reflection film is attached to the back surface of the body 11 through an air layer so as to prevent exposure. Then, a light deflecting layer 30 is attached to the surface 11b of the body 11 through the air layer. Thus, a linear luminance spot caused in the part 11b' of the surface 11b near the light entering surface is eliminated and the narrowframe surface light source device is obtained without executing special processing. |
