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:
Feb. 07, 2012
Filed:
Mar. 13, 2008
Kunihiro Komiya, Kyoto, JP;
Hiroshi Sawada, Kyoto, JP;
Kunihiro Komiya, Kyoto, JP;
Hiroshi Sawada, Kyoto, JP;
Rohm Co., Ltd., Kyoto-shi, Kyoto, JP;
Abstract
A light emitting diode driving apparatusof the present invention includes: a driving voltage generating sectionfor generating a driving voltage Vout of an LED; a driving current control sectionfor PWM controlling driving currents iWto iWthat flow through the LED; and a monitor voltage generating sectionthat monitors the driving voltage Vout, and that generates a monitor voltage Vm during an OFF period of the driving current by superposing on a predetermined reference voltage Vref, which is used as a standard, a voltage corresponding to a difference occurring in the driving voltage Vout during the OFF period. The driving voltage generating sectionperforms feedback control of the driving voltage Vout such that feedback voltages VWto VWare equal to the reference voltage Vref during an ON period of the driving current, and the driving voltage generating sectionperforms feedback control of the driving voltage Vout such that the monitor voltage Vm is equal to the reference voltage Vref during an OFF period of the driving current Vout.