Method of controling illumination device based on current-voltage model

A method of controlling an illumination device comprising a number of LEDs emitting light, the method comprising:

• receiving an input signal indicative of at least a color and/or brightness;
• generating an activation signal for at least one of said LEDs;
• receiving a voltage across said LED;
• and
• receiving a current through said LED,
• wherein said activation signal is generated based on said input signal, said voltage, said current and a current-voltage model related to said LED, where said current-voltage model defines a relationship between said current, said voltage and colorimetric properties of light emitted by said LED, wherein said colorimetric properties comprise values describing at least one of a color and spectra of said light, and wherein said relationship is defined by a look up-table comprising a number of measured calibration points, wherein each of said calibration points comprises a measured voltage across said LED, a measured current through said LED and measured colorimetric properties related to said light emitted by said LED.

An illumination device comprising:

• a number of LEDs emitting light;
• means for receiving an input signal indicative of at least one of a color and a brightness;
• and
• means for generating an activation signal for at least one of said LEDs based on said input signal,
• wherein the illumination device comprises:
• means for receiving a voltage across said at least one LED;
• and
• means for receiving a current through said at least one LED, and
• wherein the means for generating said activation signal is adapted to generate said activation signal based on said voltage, said current and a current-voltage model related to said at least one LED, wherein said current-voltage model defines a relationship between said current, said voltage and colorimetric properties of said light emitted by said at least one LED, wherein said colorimetric properties comprise values describing at least one of a color and spectra of said light, wherein said relationship is defined by a current-voltage function, wherein said current-voltage function is defined based on a number of measured calibration points, and wherein each of said calibration points comprise a measured voltage across said LED, a measured current through said LED and measured colorimetric properties related to said light emitted by said LED.

A method of controlling an illumination device comprising a number of LEDs emitting light, the method comprising:

• receiving an input signal indicative of at least a color and/or brightness;
• generating an activation signal for at least one of said LEDs, where said activation signal is generated based on said input signal;
• receiving a voltage across said LED;
• and
• receiving a current through said LED,
• wherein said activation signal is generated based on said voltage, said current and a current-voltage model related to said LED, where said current-voltage model defines a relationship between said current, said voltage and colorimetric properties of light emitted by said LED, wherein said colorimetric properties comprise values describing at least one of a color and spectra of said light, wherein said relationship is defined by a current-voltage function, where said current-voltage function is defined based on a number of measured calibration points, and wherein each of said calibration points comprises measured voltage across said LED, a measured current through said LED and measured colorimetric properties related to said light emitted by said LED.

A method of calibrating an illumination device comprising a number of LEDs emitting light;

• the method comprising:
• activating at least one of said LEDs at a driving condition;
• receiving a current through said LED at said driving condition;
• receiving a voltage across said LED at said driving condition;
• measuring colorimetric properties of said light emitted by said LED at said driving condition, wherein said colorimetric properties comprise one or more values describing at least one of a color and spectra of said light;
• storing said received current, said received voltage and said measured colorimetric properties as a calibration point;
• changing said driving condition;
• repeating a number of times said steps of activating said LED, receiving the current through said LED, receiving the voltage across said LED, measuring the colorimetric properties of said light emitted by said LED, storing said received current, said received voltage and said measured colorimetric properties as another calibration point and changing said driving conditions;
• and
• creating a current-voltage model related to said at least one LED by creating at least one polynomial function based on said number of calibration points.

An illumination device comprising:

• a plurality of LEDs;
• a LED driver receiving a voltage across at least one LED included in the plurality of LEDs, and receiving a current through the at least one LED;
• and
• a processor coupled to the LED driver, the processor receiving an input signal indicative of at least one of a color and a brightness, and generating an activation signal for the at least one LED based on the input signal, the voltage, the current, and a current-voltage model associated with the at least one LED, wherein the current-voltage model defines a relationship between the current, the voltage and colorimetric properties of light emitted by the at least one LED, wherein said colorimetric properties comprise values describing at least one of a color and spectra of said light, wherein said relationship is defined by a look up-table comprising a number of measured calibration points, and wherein each of said calibration points comprise a measured voltage across said LED, a measured current through said LED and measured colorimetric properties related to said light emitted by said LED.