| 摘要 |
In a high pressure electric discharge lamp employing at least one ribbon seal incorporating a strip (3) of refractory metal foil extending through the wall of an envelope (1) of fused silica, and connected at its outer end to at least one external lead rod (5) and at its inner end to a rod (4) which constitutes or provides a support for an electrode of the lamp, with the foil and adjacent ends of the lead rod or rods and the electrode embedded in the envelope wall, wherein a said lead rod and/or an electrode rod is surrounded, over at least a part of the region of the rod which is embedded in the envelope wall, by a closely wound coil (6) of a relatively thin refractory metal wire. This enables the fused silica of the envelope to be pressed tightly around the rod in that region in manufacture while reducing the tendency to crack on cooling. |
