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. 17, 2012
Filed:
Feb. 03, 2009
Takayoshi Kitagawa, Shizuoka, JP;
Yasushi Noyori, Shizuoka, JP;
Masayasu Ito, Shizuoka, JP;
Koito Manufacturing Co., Ltd., Tokyo, JP;
Abstract
A lighting controller has current driving means which include a shunt resistor connected in series to each of multiple LEDs to detect an LED driving current, a PMOS transistor connected to the positive electrode side of each of the LEDs, and an amplifier for sending an output according to the result of comparison between the respectively detected driving current values and a reference value, and which subject each of the PMOS transistors to ON/OFF operation. Control means includes a Zener diode ZDand a Zener diode ZDfor detecting an abnormality occurring in the current driving means and for sending the abnormality detection result. The control means controls the PMOS transistor to be turned OFF after elapse of a predetermined time upon receipt of the abnormality detection result.