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:
Jun. 03, 2008
Filed:
Apr. 22, 2005
Kenichi Fukuda, Osaka, JP;
Koji Yamashita, Kyoto, JP;
Atsushi Utsubo, Osaka, JP;
Hiroshi Nohara, Hyogo, JP;
Yukiya Kanazawa, Osaka, JP;
Kenichi Fukuda, Osaka, JP;
Koji Yamashita, Kyoto, JP;
Atsushi Utsubo, Osaka, JP;
Hiroshi Nohara, Hyogo, JP;
Yukiya Kanazawa, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Matsushita Electric Works Ltd., Osaka, JP;
Abstract
Disclosed is a lighting system capable of preventing damage to an outer-tube resulting from an outer-tube discharge that often occurs at the end of useful life of a lamp. The lighting system includes: a metal halide lamp having an arc tube housed within an outer tube; and a lamp .lighting device for operating the metal halide lamp. The lamp lighting device includes: a power supply unit operable to supply an electric power to the metal halide lamp; a detecting unit operable to detect an electrical property of the metal halide lamp; a judging unit operable to judge, based on the detected electrical property, whether a currently occurring discharge is an outer-tube discharge; and an instructing unit operable to instruct the power supply unit to suspend or reduce the electric power supply to the metal halide lamp upon a judgment that the currently occurring discharge is an outer-tube discharge. The detection unit detects a lamp voltage. The judging unit judges that the currently occurring discharge is an outer-tube discharge if the detected lamp voltage differs from a lamp voltage under normal operation.