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:
Mar. 05, 2013
Filed:
Mar. 31, 2011
Ming LI, Acton, MA (US);
Kerry Denvir, Cambridge, MA (US);
Philip E. Moskowitz, Georgetown, MA (US);
Ming Li, Acton, MA (US);
Kerry Denvir, Cambridge, MA (US);
Philip E. Moskowitz, Georgetown, MA (US);
OSRAM SYLVANIA Inc., Danvers, MA (US);
Abstract
A light emitting diode (LED) controller for controlling a plurality of LED channels includes channel select circuitry, detection circuitry, and error processor circuitry. The channel select circuitry is configured to drive N−1 LED channels of a plurality of (N) LED channels at a nominal modulation frequency and to selectively drive a selected one of the N LED channels at a probe modulation frequency. The detection circuitry is configured to receive a composite brightness signal corresponding to brightness signals from the N LED channels. The detection circuitry is further configured to filter the composite bright signal and generate a selected brightness signal corresponding to a brightness of the selected LED channel at the probe modulation frequency. The error processor circuitry is configured to compare the selected brightness signal to user defined and/or preset photometric quantities and generate a control signal for adjusting the brightness of the selected LED channel.