| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce power consumption by keeping the lowest illuminance and appropriately corresponding to the presence of a person by lighting a lighting system corresponding to a person-detecting means and a person-not-detecting means of person sensing means individually installed in plural lighting systems so as to have specified brightness based on each specified brightness and brightness detected with an illuminance sensor. SOLUTION: The whole illuminance based on an illuminance sensor 3 connected to person sensing sensors 21-24 acting as person sensing means connected to lighting systems 11-14 is kept in an object illuminance by lowering a dimming degree of the lighting systems 11-14 when the illuminance is higher than object illuminance and heightening the dimming degree when it is lower than objective illuminance. A lighting system not detecting a person of the person sensing sensors 21-24 is subjected to light decrease or lights-out. When the whole person sensing sensors 21-24 do not detect a person, the lowest illuminance is ensured, and a person present portion is sufficiently illuminated with plural lighting systems. A lighting system not detecting a person may be kept in brightness dividing equally the remaining obtained by deducting the illuminance of the lighting systems during lighting from the object illuminance.</p> |
