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Illumination device and temperature calibration method

  • US 9,651,632 B1
  • Filed: 08/20/2013
  • Issued: 05/16/2017
  • Est. Priority Date: 08/20/2013
  • Status: Active Grant
First Claim
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1. A method for calibrating an illumination device comprising at least a first light emitting diode (LED), the method comprising:

  • subjecting the first LED to a first ambient temperature;

    measuring a forward voltage developed across the first LED upon applying a non-operative drive current ranging between 0.1 mA and 10 mA to the first LED while turning off all other LEDs in the illumination device, wherein when all other LEDs are turned off occurs in time slots between when the illumination device produces illumination;

    detecting at least a first, a second and a third luminous flux output from the first LED upon successively applying at least a first, a second and a third drive current to the first LED, wherein the first, the second and the third drive currents are each operative drive currents and are different from one another and substantially greater than the non-operative drive current, wherein the first drive current is substantially equal to a maximum drive current of approximately 500 mA; and

    storing results of the measuring and detecting steps within the illumination device to calibrate the first LED at the first ambient temperature.

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