| 摘要 |
1,189,422. Mercury-vapour lamps. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 6 Feb., 1968 [9 Feb., 1967], No. 5902/68. Heading H1D. A high-pressure mercury vapour discharge lamp, the filling of which includes halide partly in liquid form at the operating temperature, has an envelope which includes a central part 19 of uniform cross-section, joined at one or (as shown) both ends to a conical part 20 by an annular ledge 21 which lies at an angle of between 90 and 110 degrees with the wall of the central part, which ledge is screened from direct heat radiation from the adjacent electrode 14 by the conical part 20 whereby liquid halide is trapped at the ledge, and unsteady operation due to droplets of halide draining down to the electrode, and being suddenly evaporated thereby, is avoided. Heat shields 25, 26 of zirconium oxide maintain the conical portions at a sufficient temperature to prevent condensation of halide therein. The filling may include the iodides of Na, K, In, Tl, Sn, or Li, together with argon, and the lamp may have a double envelope (Fig. 1, not shown). |
