| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a lighting device which can adjust chromaticity and brightness of illumination light. SOLUTION: The level of current supplied to a light-emitting diode is controlled by a current value control circuit 12 and a current source for driving an LED 11, and the ratio of on-time and off-time of current supplied to the light-emitting diode is controlled by a switch 14, a duty-ratio control circuit 16, and a PWM generating circuit 13. Since phosphors are made to emit light with light obtained by supplying the light-emitting diode with the current thus controlled, illumination light from a white LED 15 has stabilized chromaticity and luminous intensity.</p> |
