The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 30, 2003
Filed:
Aug. 24, 2001
Masaaki Muto, Kawasaki, JP;
Stanley Electric Co., Ltd., Tokyo, JP;
Abstract
A metal halide discharge lamp can include a light emitting tube having a discharge chamber formed in the light emitting tube and containing no mercury. A pair of electrodes can be provided with a portion, which projects into the discharge chamber. The discharge chamber can include a buffer gas, which also acts as a starter gas, of xenon (Xe) in an amount of 7-20 atmospheres at room temperature, and at least one kind of metal halide. The light emitting tube can have a positive resistance range in current-voltage characteristics relative to a varying input electric power. In the positive resistance range, the light emitting tube can be driven by an electric power which is less than or equal to a rated power supplied during steady lighting. In the metal halide lamp of the invention, even if the input electric power to the light emitting tube is varied, sudden unintentional extinguishment does not occur, and varying range of light color can be narrowed.