| 摘要 |
PURPOSE:To enable the breakage of a luminous tube to be prevented when an excess current flows in the lamp by using a conductive wire having fusing function in special relation to the starting rare gas sealed in the luminous tube, as the lead wire to be connected to the cap metal led out from the external tube stem. CONSTITUTION:Wells 10, 11 are connected to the cap metal 4. That is, wells 10, 11 are connected to seal-in wires 20, 21 made of dumet wires etc. At least one of lead wires 22 and 23 has fusing function, not only this wire is built by a conducting wire of melting point less than 2,000 deg.C, but also is built to satisfy logP<=0.4(IL/S)+0.7 in case of sectional area of this conducting wire being Smm.<2>, lamp current being IL(Ampere) and sealed-in pressure of starting rare gas sealed in the luminous tube being P(Torr). Through the abovementioned process, the external lead wire is fused off and breakage of the luminous tube can be prevented in case of an excess current flowing in the lamp. |
