| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a lighting control method capable of propery controlling constant illuminance, despite only few room illuminance measuring places. SOLUTION: Reference dimming depth 1 determining so as to cancel the influence of lamp light flux decay with the lapse of the cumulative lighting time of a fluorescent lamp is determined. From the reference dimming depth 1, practical dimming depth which is obtained by increasing or decreasing correction dimming portion 3, which is a value corresponding to measured room illuminance, determining so as to relieve the change of room illuminance is determined. A lighting circuit for the fluorescent lamp is controlled so as to obtain the practical dimming depth.</p> |
