| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide the optimum lighting environment corresponding to the biological rhythm of man by lighting a first light source of low color temperature in the tranquilized period of the biological rhythm of man, and lighting a second light source of high color temperature in the activated period of the biological rhythm of man. SOLUTION: For example, a ceiling light consists of the first and second annular fluorescent tubes. The first fluorescent tube is a fluorescent lamp of bulk color (color temperature 3000K) having a small diameter, and the second fluorescent tube is a fluorescent lamp of daylight color (color temperature 6500K) having a large diameter. The ceiling light can be gradually modulatably switched on and off by a switch S1. When a control 3 is adjusted to a position of 'LOW', only the first fluorescent tube is lighted, when the control 3 is adjusted to a position of 'HIGH', only the second fluorescent tube is lighted, and when the control 3 is adjusted to a position 'MIDDLE', the first and second fluorescent tubes are lighted. Whereby the first fluorescent tube of low color temperature and low luminescent level is lighted in the tranquilized period, and the second fluorescent tube of high color temperature and high luminescent level is lighted in the activated period.</p> |
