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:
Feb. 21, 2006
Filed:
Sep. 25, 2003
Takashi Kambara, Ikeda, JP;
Toshifumi Tanaka, Katano, JP;
Takashi Kambara, Ikeda, JP;
Toshifumi Tanaka, Katano, JP;
Matsushita Electric Works, Ltd., Osaka, JP;
Abstract
An electronic ballast for a discharge lamp has a controller that increase luminous flux of the lamp to a stabilized level in a constant time irrespective of possible variations in lamp characteristic. The controller utilizes a reference lamp power table and a reference lamp voltage table respectively defining a reference lamp power and a reference voltage varying with time. The controller includes a voltage deviation detector that gives a voltage correction index indicating a voltage deviation between the reference voltage and a monitored lamp voltage. The voltage correction index is processed at an offset provider that gives an offset power. A target power generator is included to correct the reference lamp power in view of the offset power, thereby generating a target lamp power which is constantly updated and is supplied to the lamp.