| 摘要 |
<p>PROBLEM TO BE SOLVED: To increase luminance and to improve the service life and the color of a lamp by arranging an electromagnet in a manner to give a substantially lateral magnetic field to an arc path in order to deflect the arc. SOLUTION: Ends of pole plates 68, 70 arranged on both sides of a lamp 62 terminate at the horizontal surface of a first focus region, and the length of their surfaces is larger than that of discharge. Magnetic deflection is correctly calibrated by an adjustment device 76 by the use of an adjustment device 74 in order to switch over to a first and a second power conditions for a low and a high beam patterns. Thereby, a continuous smaller magnetic field having the first power condition can be provided by an electromagnet 72. The first power level arranges an arc in the first focus region on the lamp axis. In addition, relatively large, continuous magnetic force having the second power condition can be also provided by the electromagnet 72, so that the arc is arranged in a second focus region which is a position where the arc arrives when deflected under the lamp axis.</p> |
