| 摘要 |
PROBLEM TO BE SOLVED: To provide a low cost lighting device, capable of readily adjusting the light output for each of lighting parts, and moreover, capable of obtaining suitable average luminance and luminance contrast according to the needs of commodity. SOLUTION: The lighting device is provided with a lighting part 1 for making a light irradiated on a display panel; an emergency power source 2 as a power source at power failure; a charge circuit part 31 for receiving power supply from a commercial power source AC and charging the emergency power source 2; a normal lighting circuit part 32 for receiving power supply from the commercial power source AC at non-power-failure and lighting up the lighting part 1; and an emergency lighting circuit part 33 for receiving power supply from the emergency power source 2, at power failure and lighting up the lighting part 1. The lighting part 1 is provided with a light-emitting diode 11 as a light source, as well as, a variable resistance R for adjusting an optical output of the light-emitting diode 11 by adjusting current flowing to the light-emitting diode 11 according to adjustment operation. COPYRIGHT: (C)2010,JPO&INPIT |
