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:
Jan. 28, 2020
Filed:
Sep. 05, 2018
Rohm Co., Ltd., Kyoto, JP;
Yasunori Muramatsu, Kyoto, JP;
Tetsuo Tateishi, Kyoto, JP;
Rohm Co., Ltd., Kyoto, JP;
Abstract
An LED driver includes a constant current circuit for supplying a constant current to a light-emitting portion composed of LEDs, a main transistor inserted serially between the light-emitting portion and the constant current circuit, a sub transistor connected to the node between the constant current circuit and the main transistor, and a control circuit. The LED driver drives the main transistor with pulses to make the light-emitting portion emit light in pulses. The control circuit, before turning on the main transistor, turns on the sub transistor to pass the constant current in the constant current circuit via the sub transistor, and, when turning on the main transistor, turns off the sub transistor.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile