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:
Oct. 29, 2013
Filed:
Apr. 28, 2011
Feng Xu, Gunma, JP;
Yoshio Fujimura, Gunma, JP;
Feng Xu, Gunma, JP;
Yoshio Fujimura, Gunma, JP;
ON Semiconductor Trading, Ltd., Hamilton, BM;
Abstract
A control circuit of a light-emitting element comprises a rectifying unit () which full-wave rectifies an alternating current power supply, a switching element (), a reference voltage generating unit () which generates a reference voltage (Vref), and a comparator () which receives a voltage (Srec) rectified by the rectifying unit (), compares a comparative voltage (Vcmp) corresponding to a current flowing to an LED () and the reference voltage (Vref), and controls switching of the switching element () according to a comparison result, wherein the reference voltage generating unit () comprises a voltage dividing circuit having a transistor (Q) in which a resistance value between a source and a drain is changed according to the voltage rectified by the rectifying unit (), and outputs, using the voltage dividing circuit, the reference voltage (Vref) according to the voltage (Srec) rectified by the rectifying unit ().