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:
Mar. 25, 1997
Filed:
Jun. 29, 1995
Kouji Kawai, Hamamatsu, JP;
Shigeki Ishihara, Hamamatsu, JP;
Naoki Masuda, Hamamatsu, JP;
Hirohisa Ota, Hamamatsu, JP;
Osamu Yogi, Hamamatsu, JP;
Hamamatsu Photonics K.K., Hamamatsu, JP;
Abstract
A metal halide lamp comprises a sealed tube containing mercury vapor and halide, and electrodes extending to a center of the sealed tube, supported by sealed portions at both ends of the sealed tube. A notch extending in a direction perpendicular to an axis of the electrode is formed in each electrode. A transverse cross sectional area of a portion where the notch is formed is smaller than the transverse cross sectional area of another portions and functions as a heat dam portion for damming heat. Accordingly, temperature of a proximal portion from the heat dam portion to the support portion is lower than that of the same portion of the conventional electrode, and temperature of a distal end portion is higher than that of the same portion of the conventional electrode. Thus, formation of low-melting alloy due to reaction of the proximal portion of the electrode and the metal halide can be suppressed.