| 摘要 |
PROBLEM TO BE SOLVED: To reduce a parasitic noise source without decreasing the output light by electrically connecting a metal sleeve member surrounding a discharge lamp near the power feed cap of the discharge lamp and included in a concave reflector to the earth. SOLUTION: A discharge lamp 2 comprising a discharge tube 2a and a power feed cap 2b is surrounded by a circular metal sleeve member 4 near a concave reflector 1. The outside circular flange 4a of the sleeve member 4 is clamped by the outside face of the reflector 1 and the flange 5 of the power feed cap 2b, and the sleeve member 4 is held at the prescribed position by the protrusion 1a of the reflector 1. A mask 3 which is a hollow shading component is held on the reflector by two metal fastening lugs 6 on both sides of the discharge tube 2a, and one or more end sections of the fastening lugs 6 coupled with its aluminum-coated face penetrate the opening section 7 of the reflector 1. The sleeve member 4 is preferably connected to the common electric earth together with the mask 3 and the inside face of the reflector 1, and the electromagnetic radiation waves from the lamp 2 are shielded. |
