| 摘要 |
PURPOSE:To ensure proper shifting to low brightness lighting without switching off a lighting fixture during a person's egress from a lighting area by turning on the fixture at a low brightness level regardless of a brightness detection output condition for the predetermined time just after high brightness lighting. CONSTITUTION:The first timer circuit 16 outputs a high brightness lighting signal C at night via low brightness detection output A from a brightness sensor 11 for a lighting area and a human existence detection output B from a human body sensor 13, thereby causing the high brightness lighting of a lighting fixture 10 via a control circuit 18. When a person egresses to reverse a signal B and turn off a signal C, a signal D due to the signal C delayed for the predetermined time with the second timer circuit 17 is supplied through an OR circuit. Consequently, the lighting fixture 10 is forcibly turned to a low brightness lighting mode via a circuit 18, regardless of a result detected with the sensor 11. Even in lingering brightness just after the aforesaid high brightness lighting, temporary extinction similar to a daytime mode does not occur and it becomes possible to ensure high brightness lighting depending upon the existence of a person and to properly shift to low brightness lighting. |
