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:
Dec. 29, 2009
Filed:
Jan. 16, 2007
Takashi Kunimatsu, Shiga, JP;
Ryutaro Arakawa, Hyogo, JP;
Yoshiaki Hachiya, Shiga, JP;
Minoru Fukui, Osaka, JP;
Takashi Kunimatsu, Shiga, JP;
Ryutaro Arakawa, Hyogo, JP;
Yoshiaki Hachiya, Shiga, JP;
Minoru Fukui, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
There is provided a light emitting diode drive apparatus which decreases a conducted emission. The light emitting diode drive apparatus includes a light emitting diode to which a voltage is applied from a voltage source, a choke coil connected in series to the light emitting diode, a rectifier diode connected in parallel to the light emitting diode and the choke coil to supply a back electromotive force generated in the choke coil to the light emitting diode, and a switching drive circuit including a switching element and a control circuit block. The switching element determines whether a current is applied or not applied to the light emitting diode. The control circuit block controls on/off timing of the switching element to control the current flowing into the light emitting diode. The choke coil is connected between the light emitting diode and the switching element.