Method for Stabilizing the Temperature Dependency of Light Emission of an LED
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Abstract
Method for correction of the temperature dependency of a light quantity L emitted by a light emitting diode (LED), being operated in pulsed mode with substantially constant pulse duration tP, and measured in a light detector, using a predetermined parameter X, correlated to the temperature T of the LED in a predetermined ratio, whereby a correction factor K is determined from the parameter X, preferably using a calibration table, especially preferred using an analytic predetermined function, whereby the measured emitted light quantity L is corrected for the temperature contingent fluctuations of the emitted light quantity, whereby the parameter X is determined from at least two output signals of the LED, which are related to each other in a predetermined manner.
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Citations
29 Claims
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1-19. -19. (canceled)
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20. A compensation device, comprising:
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means for operating an LED in pulsed mode; means for measuring the emitted light quantity as an output signal of the LED using a light detector, to provide a measured light output value; means for determining a parameter that is related to the temperature of the LED in a predetermined relation, based on at least two output signals of the LED that are related to each other in a predetermined manner with respect to temperature; means for determining a correction factor from the parameter; and means for correcting the measured light output value for temperature-dependent fluctuations of the emitted light quantity according to the correction factor. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29)
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Specification