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:
Sep. 04, 2012
Filed:
Sep. 01, 2010
Philip E. Moskowitz, Georgetown, MA (US);
Philip E. Moskowitz, Georgetown, MA (US);
Osram Sylvania Inc., Danvers, MA (US);
Abstract
In one embodiment, the present disclosure provides a method for controlling a plurality of LED channels. The method includes receiving an LED brightness signal having a plurality of superimposed pulse width modulated (PWM) brightness signals each having a duty cycle and amplitude at a unique modulation frequency, each PWM brightness signal being proportional to the brightness of a respective LED channel. The method also includes determining a pulse area of each PWM brightness signal at each respective unique frequency. The pulse area is proportional to the product of the amplitude and the duty cycle. The method also includes generating pulse area signals proportional to the respective pulse area and comparing the respective pulse area signals to user defined and/or preset photometric values to generate respective error signals proportional to the difference between the respective pulse area signals and the user defined and/or preset photometric values.