| 摘要 |
PROBLEM TO BE SOLVED: To provide a lighting apparatus and a lighting system therewith which control lighting more in accordance with the time of sunset and sunrise.SOLUTION: A lighting control device 11 lights on a lighting fixture 12 irrespective of a detection result of an illuminance sensor 13 for a lighting time Tn from when an illuminance level Ls becomes equal to or lower than a threshold Th1 for dark/light detection (sunset decision time). If determining that the illuminance level Ls after the lapse of the lighting time Tn is lower than the threshold Th1 for dark/light detection, the lighting control device 11 decides that the current lighting time Tn is shorter than an actual time from sunset to sunrise, and sets the lighting time Tn from the next sunset decision time longer by an adjustment time Tα. If determining that the illuminance level Ls after the lapse of the lighting time Tn is equal to or higher than the threshold Th1 for dark/light detection, the lighting control device 11 decides that the current lighting time Tn is longer than the actual time from sunset to sunrise, and sets the lighting time Tn from the next sunset decision time shorter by an adjustment time T&bgr;. |
