| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide the optimum lighting environment corresponding to the biological rhythm of man by providing the lighting environment including much low color temperature light in a tranquilized period of the biological rhythm of man, and the lighting environment including much high color temperature light in a activated period of the biological rhythm of man. SOLUTION: For example, a ceiling light consists of the first and second two annular fluorescent tubes. The first fluorescent tube is a fluorescent lamp of bulk color (color temperature 3000 K) having a small diameter, and the second fluorescent tube is a fluorescent lamp of daylight color (color temperature 6500 K) 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 is adjusted to a position of (HIGH), only the second fluorescent tube is lighted, and when the control is adjusted to a position of (MIDDLE), the first and second fluorescent tubes are lighted. Whereby the light including much low color temperature light can be provided with low intensity of illumination in the tranquilized period, and the light including much high color temperature light can be provided with the high intensity of illumination in the activated period.</p> |
