| 摘要 |
1,208,508. Fluorescent discharge lamps. SYLVANIA ELECTRIC PRODUCTS Inc. 3 July, 1968 [3 July, 1967], No. 31731/68. Heading H1D. A fluorescent lamp comprises an envelope 1 containing a gas filling and a vaporizable material and having a phosphor coating 3 and two spaced sets of filaments, each set containing a cathode filament 8, 9 coated with electron-emitting material and an incandescent filament 10, 11. The supply circuit is as described in Specification 1,208,509 (see Division H2). The lamp is suitable for use in low temperature conditions, e.g. in an automobile at starting in winter, when the vapour pressure in the lamp is too low for the discharge established between the cathodes 9 and 10 by the oscillator 13 to excite the phosphor coating 3 efficiently. During this period adequate illumination is provided by the filaments 10 and 11 heated by the battery 15 and providing light which is diffused by the coating 3. |
