Patent Number: 6,528,946

Title: Compact-type metal halide discharge lamp

Abstract: A metal halide discharge lamp which essentially permits disusing mercury is provided. The metal halide discharge lamp comprises a refractory and transparent hermetic vessel, a pair of electrodes fixed to the hermetic vessel, and a discharge medium sealed in the hermetic vessel and containing a first halide, a second halide, and a rare gas. The first halide is a halide of a metal which achieves a desired light emission. The second halide has a relatively high vapor pressure, being at least one halide of a metal which is unlikely to emit a visible light compared with the metal of the first halide and acts as a buffer gas.

Inventors: Ishigami; Toshihiko (Kawasaki, JP), Saita; Kiyoshi (Yokosuka, JP), Matsuda; Mikio (Tokyo, JP), Hiruta; Toshio (Hiratsuka, JP)

Assignee: Harison Toshiba Lighting Corp.

International Classification: H01J 61/00 (20060101); H01J 61/12 (20060101); H01J 61/82 (20060101); H05B 41/28 (20060101); H05B 41/288 (20060101); H01J 017/20 (); H01J 061/12 ()

Expiration Date: 03/04/2020