| 摘要 |
PURPOSE:To enable the lighting of the high pressure discharge lamp while employing the ballast for the mercury lamp, by forming the main electrode in the light emission tube with the metallic coil while selecting the diameter of said metallic wire to be the specific relation against the volume ratio of Argon. CONSTITUTION:The silicon light emission tube 1 having the main electrodes 2a, 2b and the auxiliary electrode 3 while encapsulated with the mixture gas of neon and argon where the volume of argon is 5-20% is contained in a bulb 17 to form the metal halide lamp. The electrode 2 is formed by winding the tungsten wire coil 28 over the tungsten rod core 27, where the diameter of the wire (d) is selected such that d<=(P+47.5)/150 assuming the volume ratio of argon is P(%). Consequently when lowering the auxiliary discharge starting voltage, the high pressure discharge lamp can be lighted while employing the inexpensive ballast for the mercure lamp. |
