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:
Jun. 19, 2012
Filed:
Oct. 15, 2010
Sang Yun Lee, Gyunggi-Do, KR;
Sang Yun Lee, Gyunggi-Do, KR;
Samsung Electro-Mechanics Co., Ltd., Gyunggi-do, KR;
Abstract
A constant current controlling part of an LED array driving apparatus includes a PWM IC including an RT/T terminal for outputting a sawtooth wave voltage, a COMP terminal for receiving a comparison voltage to be compared with the sawtooth wave voltage, an output terminal for outputting a pulse signal that is turned off during an interval where the sawtooth wave voltage is higher than the comparison voltage and turned on during an interval where the sawtooth wave voltage is lower than the comparison voltage, and a comparison voltage setter setting the comparison voltage inputted to the COMP terminal. When an overvoltage is applied to the LED array or the LED array is to be turned off by an external dimming control signal, the comparison voltage setter sets the comparison voltage to a value lower than a lower limit of the sawtooth wave voltage.