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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.:

US 10766400 B1

PDFFull Text
Date of Patent:
Sep. 08, 2020

Filed:

May. 29, 2018

Vehicle lamp and lighting circuit of light source

Applicant:

Koito Manufacturing Co., Ltd., Tokyo, JP;

Inventors:

Satoshi Kikuchi, Shizuoka, JP;

Tomoyuki Ichikawa, Shizuoka, JP;

Assignee:

KOITO MANUFACTURING CO., LTD., Tokyo, JP;

Attorney:

Osha Liang LLP

Primary Examiner:

Amy Cohen Johnson

Assistant Examiner:

Syed M Kaiser

Int. Cl.
CPC ...
B60Q 1/04 (2006.01); F21S 41/141 (2018.01); B60Q 1/14 (2006.01); H05B 45/14 (2020.01); F21S 41/32 (2018.01); F21S 41/153 (2018.01); F21S 41/39 (2018.01); F21S 41/148 (2018.01); F21S 41/663 (2018.01); F21S 41/255 (2018.01); F21S 41/19 (2018.01); F21S 41/675 (2018.01); H05B 45/48 (2020.01); H05B 47/10 (2020.01); F21W 102/14 (2018.01);
U.S. Cl.
CPC ...
B60Q 1/04 (2013.01); B60Q 1/143 (2013.01); F21S 41/141 (2018.01); F21S 41/148 (2018.01); F21S 41/153 (2018.01); F21S 41/19 (2018.01); F21S 41/255 (2018.01); F21S 41/32 (2018.01); F21S 41/39 (2018.01); F21S 41/663 (2018.01); F21S 41/675 (2018.01); H05B 45/14 (2020.01); H05B 45/48 (2020.01); H05B 47/10 (2020.01); F21W 2102/14 (2018.01);
Abstract

A lighting circuit is configured to drive a light source including a plurality of light emitting elements connected in series. The lighting circuit includes a plurality of bypass switches respectively connected in parallel to the light emitting elements, a switching converter, and a converter controller configured to (i) stabilize a lamp current generated by the switching converter to a first target amount in a lighting-on state where at least one of the plurality of light emitting elements is turned on, and to (ii) stabilize the lamp current to a second target amount smaller than the first target amount in a complete lighting-off state where all of the plurality of light emitting elements are turned off.

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