Patent ID: 8708560

Claim:
A method for the temperature-dependent adjustment of color properties or photometric properties of an LED illuminating device having a plurality of LEDs in LED color groups emitting light of different colors or wavelengths, wherein luminous flux portions thereof determine the color of light, color temperature and/or chromaticity coordinates of a light mixture emitted by the LED illuminating device and are adjusted by controlling the LEDs comprising colored and white LEDs having the same color in each case by pulse-width modulated control signals, comprising: measuring a temperature within the LED illuminating device, of a board containing the LEDs or a junction temperature of at least one LED; adjusting a light mixture having a specified color of light, color temperature and/or chromaticity coordinates by adjusting pulse-width modulated control signals corresponding to the luminous flux portions of the LEDs of the light mixture; determining a dependency of the pulse-width modulated control signals on temperature from a brightness of the LEDs varying over a relevant temperature range by, determining a factor (f PWM ) corresponding to the reciprocal of a relative brightness modification of the LED color groups with respect to the basic setting, and determining a value of the pulse-width modulated control signals (PWM(T)) of each LED corresponding to the measured temperature by multiplying the basic-setting relating value of the pulse-width modulating control signals (PWM A ) of each LED with the factor (f PWM ) being dependent on the measured temperature (T) according to the equation PWM ( T )= PWM A *f PWM ; modifying the pulse-width modulated control signals PWM (T) corresponding to the luminous flux portions of the LEDs of the light mixture adjusted to a specified color of light, color temperature and/or chromaticity coordinates, the modulation being dependent on the measured temperature; and adjusting the pulse-width modulated signals (PWM (T)) of each LED at the LED illuminating device by, measuring the actual brightness of the LED illuminating device, determining the difference between the measured brightness actual value and a brightness set value, and adapting the light intensity emitted from the LED illuminating device to the brightness set value by correspondingly increasing or decreasing electric power fed to the LEDs.