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. 03, 2015
Filed:
Oct. 04, 2012
Satoshi Kikuchi, Shizuoka, JP;
Fuminori Shiotsu, Shizuoka, JP;
Takanori Namba, Shizuoka, JP;
Masayasu Ito, Shizuoka, JP;
Satoshi Kikuchi, Shizuoka, JP;
Fuminori Shiotsu, Shizuoka, JP;
Takanori Namba, Shizuoka, JP;
Masayasu Ito, Shizuoka, JP;
Koito Manufacturing Co., Ltd., Tokyo, JP;
Abstract
A circuit for lighting a semiconductor light source is provided. The circuit includes: a switching regulator including a switching element and configured to generate a drive current for the semiconductor light source using the switching element; and a control circuit configured to control on-off of the switching element such that the magnitude of the drive current comes close to a targeted value. The control circuit includes: a comparator configured to compare the magnitude of the drive current with the targeted value; an up/down counter configured to count a digital value in a counting-up direction or counting-down direction, based on a comparison result of the comparator; a digital-to-analog converter configured to convert the counted digital value into an analog signal; and a drive circuit configured to control on/off of the switching element based on the analog signal.