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:
Aug. 04, 2015
Filed:
Jul. 25, 2012
Tobias Gern, Esslingen am Neckar, DE;
Uwe Burkhardt, Lichtenstein, DE;
Frank Wimbert, Owen, DE;
Rainer Kümer, Dettingen, DE;
Tobias Gern, Esslingen am Neckar, DE;
Uwe Burkhardt, Lichtenstein, DE;
Frank Wimbert, Owen, DE;
Rainer Kümer, Dettingen, DE;
Flextronics International Kft., Tab, HU;
Abstract
A method for obtaining PWM values for an LED module having n LED chips from various color ranges, wherein n>1, wherein for each LED chip a PWM value for producing a target color value is obtained, is characterized in that a calibration measurement is performed in which the wave lengths (λ, λ, λ) and/or the standard color proportion values ((x,y), (x,y), (x,y)) and possibly the luminous flux values of the individual LED chips are determined at a calibration temperature (T), PWM control points are obtained, where each PWM control point contains a PWM value for each of the n color ranges of the LED module, during operation of the LED module a value that depends on the present temperature (T) of the LED module, in particular the present temperature (T) itself, is determined, and a first and a second PWM control point are assigned to this temperature-dependent value, and the PWM values for producing the target color value are obtained through interpolation between the assigned PWM control points. This makes it possible to realize a precise color mixture in the LED module in a cost-effective way, with little computing power, despite temperature fluctuations (and possible electric current fluctuations).