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:
Nov. 06, 2012
Filed:
Oct. 15, 2009
Masahiko Kamata, Yokohama, JP;
Hajime Osaki, Yokosuka, JP;
Hirokazu Otake, Yokosuka, JP;
Shinya Hakuta, Yokohama, JP;
Takuro Hiramatsu, Yokohama, JP;
Toshiyuki Hiraoka, Numazu, JP;
Naoko Iwai, Yokohama, JP;
Masahiko Kamata, Yokohama, JP;
Hajime Osaki, Yokosuka, JP;
Hirokazu Otake, Yokosuka, JP;
Shinya Hakuta, Yokohama, JP;
Takuro Hiramatsu, Yokohama, JP;
Toshiyuki Hiraoka, Numazu, JP;
Naoko Iwai, Yokohama, JP;
Toshiba Lighting & Technology Corporation, Kanagawa, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
There is provided an LED lighting device having a satisfactory temperature characteristic and a small amount of variation in output current. The step-down chopper is provided with a first circuit including the switching element, the impedance means and a first inductor connected in series and a second circuit including the first inductor and a diode connected in series. A self-excited drive signal generation circuit is provided with a second inductor magnetically coupled with the first inductor and applies a voltage induced in the second inductor to the switching element to keep the switching element on. A turn-off circuit outputs an output voltage when the voltage of the impedance means detected by a comparator exceeds the reference value, and the output voltage allows a switching element to turn on to short-circuit the output terminals of the self-excited drive signal generation circuit, resulting in that the switching element is turned off.