| 摘要 |
PURPOSE:To improve the rising characteristic, by providing spacers sandwiched between the outside circumferential surface of a miniaturized fluorescent tube 10 housed in a box-shaped case and the inside surface of the box-shaped case so that the two surfaces are kept apart from each other. CONSTITUTION:Holding means 22 consist of projecting parts which protrude toward housing space P at the front side of both ends of a box-shaped case 21 in such a manner that the projecting parts approach each other. A miniaturized fluorescent tube 10 housed in the case 21 is held in the holding space P by being sandwiched between the means 22. Sandwiching the tube 10 between the means 22 at the coldest parts of the tube 10 brings about less heat loss and faster rise of luminance. Spacers 23 are formed in one body with the case 21 and are put between the rear side of an outside circumferential surface of the tube 10 and the inside surface of the case 21 on both end parts or the case 21 so that the two surfaces are kept apart from each other. Further, setting the spacers 23 to touch the tube 10 at positions other than the coldest parts of the tube 10 decreases heat loss out of the coldest parts. Heat is thereby utilized efficiently to warm up the tube, and as a result, faster rise of luminance is brought about. |
