To keep illuminance of a lighting object unchanged even if external light fluctuates, in a lighting system utilizing external light.
The lighting system utilizing external light 1 includes: a daylighting device 2 arranged near openings of a house and collects the external light; a light guide device 3 to perform light guiding of the collected light; an irradiation device 5 to irradiate the guided light to an irradiating object; a light-emitting device 6 to supplement the light of the irradiation device 5, by irradiation with supply of power; a brightness sensor 7 to measure brightness of the irradiating object; and a controlling device 8 to control an output of the light-emitting device 6 based on the measurement result of the brightness sensor 7 in order to keep the brightness of the irradiating object at a predetermined illuminance level. This keeps the illuminance at the irradiating object unchanged even if the external light fluctuates.
KADONO TAKESHI
SAKAI KYOKO
| JPS61194909U | 1986-12-04 | |||
| JPH01186501A | 1989-07-26 | |||
| JPH06111610A | 1994-04-22 | |||
| JP2000057820A | 2000-02-25 | |||
| JPH11283416A | 1999-10-15 | |||
| JPS6355803A | 1988-03-10 |
Katsumi Taguchi
Shinichi Mizuta