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:
Sep. 15, 2015
Filed:
Jun. 13, 2012
Feng Xu, Kiryu, JP;
Shuhei Kawai, Ota, JP;
Tomoyuki Goto, Ota, JP;
SEMICONDUCTOR COMPONENTS INDUSTRIES, LLC, Phoenix, AZ (US);
Abstract
In accordance with an embodiment, a light emitting element driving circuit includes a comparator having an input connected to smoothing circuit and an output connected to a voltage-dividing circuit through a transistor. A drain-to-source resistance of the transistor is connected in parallel with a portion of the voltage dividing circuit. An output signal of the voltage dividing circuit is connected to another comparator that generates a drive transistor drive signal. The drive transistor is connected to one or more light emitting elements. In accordance with another embodiment, a reference voltage is generated in response to a rectified signal and compared with a sense voltage to generate a drive signal that is used to drive the drive transistor. Light is emitted from the one or more light emitting elements in response to the drive signal and the rectified voltage being greater than the forward voltage drops of the one or more light emitting elements.