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.

Date of Patent:
Jul. 02, 2013

Filed:

Aug. 05, 2011
Applicants:

Kotaro Matsui, Shizuoka, JP;

Takao Sugiyama, Shizuoka, JP;

Inventors:

Kotaro Matsui, Shizuoka, JP;

Takao Sugiyama, Shizuoka, JP;

Assignee:

Koito Manufacturing Co., Ltd., Minato-ku, Tokyo, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B 37/02 (2006.01); H05B 37/00 (2006.01);
U.S. Cl.
CPC ...
Abstract

A lighting circuit includes: a countercurrent prevention unit including a first control terminal and a second control terminal, the countercurrent prevention unit transmitting a first current or a second current; and a current controller including: a common terminal connected to the first control terminal and the second control terminal; and a switching terminal connected to the first control terminal, the current controller providing a first driving current or a second driving current from the common terminal to the light source. The countercurrent prevention unit further includes: a first rectifier, wherein voltage at the first control terminal is provided to the switching terminal through the first rectifier; a first P-FET provided between the first control terminal and the common terminal; a second P-FET provided between the second control terminal and the common terminal; and a second rectifier provided between the second P-PET and the common terminal.


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