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:
Aug. 05, 2014
Filed:
Dec. 02, 2009
Shigeyasu Soma, Muroran, JP;
Tetsuo Terashima, Chino, JP;
Shigeyasu Soma, Muroran, JP;
Tetsuo Terashima, Chino, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
In at least one embodiment of the disclosure, a driving device for a discharge lamp includes an alternating current supply section and a frequency modulation section. The alternating current supply section supplies two electrodes of the discharge lamp with an alternating current. The alternating current comprises a plurality of modulation periods. The frequency modulation section modulates a frequency of the alternating current so as to provide a plurality of retentive periods within each of the modulation periods. Each retentive period has a constant frequency that is different from a frequency of its temporally adjacent retentive periods. The frequency modulation section shortens a length of at least one of the retentive periods in the modulation period in response to a predetermined condition occurring. The frequency of at least one of the retentive periods is equal to or less than a predetermined reference frequency.