| 摘要 |
PURPOSE:To obtain a fluorescent lamp unit that optimizes its mercury vapor pressure and suppresses the degradation of a luminous flux under a low temperature atmosphere not only by dissipating the heat generated by a bulb but also by applying the heat to the tube wall of the fluorescent lamp. CONSTITUTION:A power supply and a fluorescent lamp 1 are connected through a bulb metal cap 4. A bulb 5 acting as a resistance ballast is inserted in either of lead wires that connect the bulb metal cap 4 and the fluorescent lamp 1. A starter 6 connects the non-power supply side terminals of both filaments of the fluorescent lamp 1. In the said fluorescent lamp unit, the air heated by the heat of the bulb 5 is not contained in a holder 2 but is diffused at an enclosure side through a connecting groove 11. As a result, the temperature rise in the holder 2 can be restrained remarkably as compared with the case where the inner part of the holder is closed tightly. Besides, the heat transferred in the enclosure 7 can warm the outer surface on the tube wall of the fluorescent lamp 1 and restrain the degradation of luminous flux caused by the tube wall temperature fall, i.e. mercury vapor pressure drop. |
