| 摘要 |
PROBLEM TO BE SOLVED: To provide a planar light source which economizes power consumption of back light for an illumination sign board, several kinds of signs and a liquid crystal display device, and save electricity even during display operation, and to provide liquid crystal display using it. SOLUTION: This surface light source comprises an emission part (light- introducing plate 22) having a light irradiation part irradiating light of a light source 21 in a surface, a light absorption-emission part 24 arranged adjacent to the light-radiation part, and a control circuit 25 turning on and off the light source 21. The surface light source economizes power consumption with the off time of the light source 21 by turning on and off the light source 21 with the control circuit 25 and continuously irradiating light with the help of light absorption-emission part 24. Accordingly this liquid crystal display device is provided by disposing the planar light source on the rear side of a liquid crystal panel. |
