| 摘要 |
<p>PURPOSE:To perform proper illumination control by changing the delay time until the illumination state is changed. CONSTITUTION:A processor 112 monitors the photo-sensor output, i.e., external light intensity, and changes the illumination state after the preset delay time when the intensity exceeds the threshold value at the time A or when the intensity is below the threshold value at the time B. The processor 112 functions as a change direction detecting means and detects whether the intensity is increasing or decreasing. The direction that the intensity is increasing is detected at the time A, and the direction that the intensity is decreasing is detected at the time B. The processor 112 generates, outputs, and stores the control data to change the illumination state after the delay time t1 from the time A. The processor 112 generates, outputs, and stores the control data to change the illumination state after the delay time t2 (=t1/2) from the time B. Since t2 is shorter than t1, the illumination state is quickly changed when the intensity becomes dark, and precise illumination control can be performed.</p> |
