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Interference-resistant compensation for illumination devices having multiple emitter modules

  • US 9,332,598 B1
  • Filed: 10/09/2014
  • Issued: 05/03/2016
  • Est. Priority Date: 08/20/2013
  • Status: Expired
First Claim
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1. A method for controlling an illumination device comprising multiple emitter modules, wherein each emitter module comprises multiple emission light emitting diode (LED) elements and one or more photodetectors, the method comprising:

  • operating one or more of the multiple emission LED elements in each of the multiple emitter modules to produce illumination substantially continuously by supplying a respective drive current at an operative drive current level to each of the one or more of the multiple emission LED elements;

    bringing the respective drive currents of all except one of the emission LED elements within a first emitter module of the multiple emitter modules to a non-operative drive current level, which is insufficient to produce illumination, for the duration of a measurement interval within a first series of measurement intervals interspersed with periods of said illumination; and

    bringing the respective drive currents of all except one of the emission LED elements within a second emitter module of the multiple emitter modules to a non-operative drive current level, which is insufficient to produce illumination, for the duration of a measurement interval within a second series of measurement intervals interspersed with periods of said illumination, wherein the first series of measurement intervals and the second series of measurement intervals are separated by a respective first offset and second offset from a timing reference.

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