| 摘要 |
PURPOSE: To provide an efficient exciting coil by winding the exciting coil along the outer surface of an imaginary ring having a V-shaped cross section, and tuning it to the desired resonance frequency. CONSTITUTION: A lamp 10' has a circular outer tube 22 mounted on the outer surface 11a of an arc tube 11, and a discharge plasma 14 is produced adjacent to the inner surface 11b of the arc tube 11. An exciting coil 24 is wound along the outer surface of a ring 24' having a V-shaped cross section with an angleθof 10 deg. to 80 deg., within the same plane 24'p as the plasma 14 around the outer tube 22. The coil 24 is made to resonate at the desired frequency by means of the inductance of the coil 24 and a composite capacity comprising series capacities 26, 28. Therefore, efficient excitation can be achieved. |
