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. 25, 2005
Filed:
Oct. 07, 2003
Masayasu Ito, Shizuoka-ken, JP;
Hiroki Ishibashi, Shizuoka-ken, JP;
Kentaro Murakami, Shizuoka-ken, JP;
Hitoshi Takeda, Shizuoka-ken, JP;
Masayasu Ito, Shizuoka-ken, JP;
Hiroki Ishibashi, Shizuoka-ken, JP;
Kentaro Murakami, Shizuoka-ken, JP;
Hitoshi Takeda, Shizuoka-ken, JP;
Koito Manufacturing Co., Ltd., Tokyo, JP;
Abstract
A lighting circuit for lighting a vehicular lamp including a light-emitting diode, includes: a switching regulator for applying an output voltage based on a power-supply voltage received from a DC power supply provided in the outside thereof to the light-emitting diode so as to supply a supply current to the light-emitting diode; an abnormal state detector for detecting an abnormal state of the lighting circuit based on at least one of the output voltage of the switching regulator, the supply current and the power-supply voltage; and an output controlling unit for controlling the output voltage of the switching regulator based on the supply current or the output voltage of the switching regulator and lowering the output voltage of the switching regulator in a case where the abnormal state detector detected the abnormal state.