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:
Jul. 10, 2018
Filed:
Jul. 21, 2017
Seiko Epson Corporation, Tokyo, JP;
Masaru Kono, Shiojiri, JP;
SEIKO EPSON CORPORATION, Tokyo, JP;
Abstract
A discharge lamp driver includes a discharge lamp driving unit configured to supply drive current to a discharge lamp and a control unit configured to control the discharge lamp driving unit. The drive current has a modulation drive period in which a first period in which AC current having a frequency higher than 1 kHz is supplied and a second period in which DC current is supplied are alternately repeated. In the modulation drive period, the control unit periodically changes length of a first DC period included in the second periods and in which DC current of a first polarity is supplied, and length of a second DC period included in the second periods and in which DC current of a second polarity is supplied, and increases one of the length of the first DC period and the length of the second DC period while decrease the other one.