To produce a state in which each of LEDs 11a-11c independently emits light at a predetermined timing within a single cycle, irrespective of the duty ratio.
The lighting system includes LEDs 11a-11c which respectively emit light of different colors, and a light-receiving element 14 for measuring emission amounts of light emitted from the respective LEDs 11a-11c together. The lighting system controls the light emission time in one cycle of the respective LEDs 11a-11c, and periodically controls light emission and non-light emission of the respective LEDs 11a-11c, while maintaining the light emission time. The light emission time in a single cycle is controlled, based on the color mixture ratio data of the respective colors to obtain a desired chromaticity and the emission amount of the light measured by the light-receiving element 14. The maximum value and the minimum value of the light emission time on the respective LEDs are determined, the time of a single cycle of the (k+1)th LED is set to be equal to a minimum value of the non-light emission time of the k-th LED, and the maximum value of the light emission time of the k-th LED is set to be a positive integral multiple of the minimum value of the non-light emission time of the k-th LED.
COPYRIGHT: (C)2011,JPO&INPIT
Kenichi Irie
| JP200780540A | ||||
| JP2008166101A | ||||
| JP2007235050A | ||||
| JP2005302737A |
Mizuhiji Katsuhisa
Takeshi Sakaguchi
Hidetoshi Kitade