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. 07, 2020
Filed:
Mar. 12, 2018
Applicants:
Yuuki Oka, Miyagi, JP;
Tsuyoshi Ueno, Miyagi, JP;
Seiya Abe, Fukuoka, JP;
Inventors:
Assignee:
RICOH COMPANY, LTD., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01S 5/042 (2006.01); H02M 1/32 (2007.01); H02M 1/36 (2007.01); H02M 3/158 (2006.01); H05B 33/08 (2006.01);
U.S. Cl.
CPC ...
H01S 5/042 (2013.01); H02M 1/32 (2013.01); H02M 1/36 (2013.01); H02M 3/1588 (2013.01); H05B 33/0815 (2013.01); Y02B 70/1466 (2013.01);
Abstract
A drive circuit is configured to supply a current to a light emitting element. The drive circuit includes a plurality of switching elements configured to switch between ON/OFF states with a modulation signal, a capacitor connected in parallel with the light emitting element, and a control module configured to control the switching elements so that a voltage of the capacitor does not become lower than a threshold.