| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lighting device that contributes to energy saving by preventing an excessive lamp output in constant-illuminance control. <P>SOLUTION: A control part 2 has a constant-illuminance control function for keeping the illuminance of a face to be irradiated constant on the basis of an illuminance detection value by an illuminance detecting part 1. In constant-illuminance control, a reference curve and a correction factor are used in order to calculate and set an illuminance target value while the brightness is controlled such that the illuminance detection value becomes constant in accordance with the illuminance target value. The reference curve is an illuminance reference value corresponding to each dimming level in which a dimming level is changed in a standard state of the face to be irradiated. The correction factor is calculated on the basis of a reflectance of the actual face to be irradiated. Here, it is configured to use the following factor as the correction factor, that is, a factor that is calculated by adding a light-source output or an illuminance detection value of the face to be irradiated in a state that the output of a fluorescent lump 12 being a light source is stable. <P>COPYRIGHT: (C)2010,JPO&INPIT |
