EP4061098A1 - Method and calibration device for calibrating colour or photometric properties of an led lighting device - Google Patents
Method and calibration device for calibrating colour or photometric properties of an led lighting device Download PDFInfo
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- EP4061098A1 EP4061098A1 EP22162158.4A EP22162158A EP4061098A1 EP 4061098 A1 EP4061098 A1 EP 4061098A1 EP 22162158 A EP22162158 A EP 22162158A EP 4061098 A1 EP4061098 A1 EP 4061098A1
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- color
- led
- light
- leds
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/20—Controlling the colour of the light
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/20—Controlling the colour of the light
- H05B45/22—Controlling the colour of the light using optical feedback
Definitions
- the present invention relates to a method for calibrating color or photometric properties of an LED lighting device and a corresponding calibration device for calibrating color or photometric properties of an LED lighting device, with which the time required for the calibration of color or photometric properties of a LED lighting device can be significantly reduced.
- the multicolored LED units usually include a number of single-color LEDs and are controlled with LED drivers which are designed to vary the brightness and the color location, ie the mixed color.
- the corresponding multi-color LED unit is usually calibrated.
- One or more color locations and/or brightnesses of the multicolored LED unit are specified and the individual LED chips are controlled sequentially, ie one after the other, in order to assign corresponding state variables, for example control signals.
- the color of a light source is generally further determined using a standard color table.
- This standard color chart is defined in the DIN 5033 standard or in the equivalent CIE 1931 standard, with a color being defined by an x and a y coordinate. Furthermore, all colors visible to a human being lie within a color triangle.
- the individual LED chips of the LED unit are usually calibrated corresponding emission spectra are recorded sequentially, that is to say controlled one after the other, and the individual emission spectra are converted into a known color space, for example CIE 1931.
- tristimulus values (X,Y,Z), which indicate the corresponding proportions of the three primary colors red, green and blue, can be calculated.
- the calculated tristimulus values are then stored in association with correspondingly existing or predetermined state variables, for example the existing electrical control or the corresponding control signal, the current temperature of the corresponding LED chip, etc., in order to be able to control the individual LED chips accordingly in the future.
- a method for controlling the light output of at least three light sources is known, with the light emitted by the light sources being recorded in a sequence of measurement periods during a calibration phase and the brightness of each individual light source being calculated on the basis of the information contained in the measurement periods. In at least one of the measurement periods, the recorded light originates from several of the light sources.
- a method for simulating high quality daylight spectra wherein light is generated with a plurality of LEDs arranged in groups, each group emitting light with different wavelengths lying within the daylight spectrum, the wavelength of that of each LED at different Working temperatures and PMW values of the emitted light are measured and measurement results are stored for each LED in association with working temperatures and PMW values.
- the individual LEDs are then controlled with stored values depending on the light to be emitted by each group, with the working temperature of each individual LED chip being constantly measured and compared with the values stored for the current working temperature, with compensation being provided in the event of a deviation between the values by a
- the spectrum is recalculated taking into account the PWM values stored for the working temperature and the corresponding LED chip is controlled with the newly calculated value.
- a method for emitting and modulating light with a specified light spectrum is known, with a lighting device having a plurality of groups of light-emitting devices, each group of which emits a specified light spectrum, and a control device controls the energy supply to the individual light-emitting devices in such a way that the overall resultant Radiation has a predetermined light spectrum.
- a light source for daylight with an adjustable color temperature in which at least one white light from an LED is combined with LEDs emitting different colored light, in particular in the primary colors red, green and blue.
- a specific color temperature or a specific standard light source can be set by automatically adjusting or readjusting a specified color temperature or standard light quality using suitable sensors, logic and software that can record the current spectral profile of the light source becomes.
- WO 2009/034060 A1 is a method for the temperature-dependent adjustment of the color or photometric properties of an LED lighting device with LEDs or LED color groups emitting light of different colors or wavelengths, which emit light of the same color or wavelength within a color group, whose luminous flux components determine the light colour, color temperature and/or the Determine the color locus of the light mixture emitted by the LED lighting device.
- the actual temperature value is measured on and/or within the LED lighting device, in particular an on-board temperature of the LEDs arranged on a circuit board or the junction temperature of at least one LED.
- a temperature dependent Value determined which determines or co-determines the wavelength-dependent emission spectra of the different-colored LEDs at the measured temperature from calibration data stored for each of the different-colored LEDs, whereby luminous flux components of the different-colored LEDs for a given light color, color temperature and/or or the light mixture having the color locus at the measured temperature is determined as a function of the determined at least one temperature-dependent value, and the determined luminous flux components are set on the different-colored LEDs.
- the pamphlet DE 10 2007 044 556 A1 describes a method for the temperature-dependent adjustment of the color or photometric properties of an LED lighting device with LEDs or LED color groups emitting light of different wavelengths, whose luminous flux components determine the light colour, color temperature and/or the color locus of the light mixture emitted by the LED lighting device.
- the board or junction temperature of an LED is measured and a temperature-dependent value is determined, which determines the wavelength-dependent emission spectra of the LEDs at the measured temperature from calibration data that are stored in advance for each of the LEDs.
- the calibration device determines the required luminous flux components of the LEDs for the specified light colour, color temperature and/or color location and then applies them.
- the pamphlet DE 10 2010 044 736 A1 describes a method for simulating daylight spectra of high quality for the purpose of illuminating matching areas when matching the color of a finished product with a template, for example in the graphics industry.
- light is first generated with a large number of LEDs, with the LED groups emitting light within the daylight spectrum.
- the wavelengths of the LEDs are measured and stored at different working temperatures and PWM values.
- the LEDs are then controlled with the saved PWM values. Temperature-related deviations should by permanent measurement and adjustment based on the stored values in the PWM/wavelength/temperature table.
- the object of embodiments of the invention is to specify an improved method or an improved calibration device for calibrating color or photometric properties of an LED lighting device.
- this object is achieved by a method for calibrating color or photometric properties of an LED lighting device with LEDs or LED color groups emitting light of different colors or wavelengths, which emit light of the same color or wavelength within a color group, whose luminous flux components determine the light color, color temperature and/or the color locus of the light mixture emitted by the LED lighting device, the method having the following steps: First, all LEDs or LED color groups of the LED lighting structures are controlled in parallel with known state variables in order to generate light, wherein a spectrum of the light generated by driving all LEDs or LED color groups in parallel is measured, and wherein emission spectra of the individual LEDs or LED color groups are determined from the measured spectrum of the light generated. Subsequently, tristimulus values are calculated based on the emission spectra of the individual LEDs or LED color groups, the calculated tristimulus values being stored in association with the known state variables.
- Parallel activation is understood here to mean that the individual LEDs or LED color groups are not activated sequentially but at the same time or all together.
- the spectrum or electromagnetic spectrum is also generally understood to mean the entirety of all electromagnetic waves of different wavelengths, with the light spectrum or color spectrum representing the range of the electromagnetic spectrum that is visible to a human being. Spectra that arise solely from the light that is emitted by a light source are also referred to as emission spectra.
- the color or photometric properties can also be a color/brightness mixing ratio, for example.
- the LED lighting device can in particular have red, green and blue LEDs.
- red, green and blue LEDs are required, with one light source being in the red range, one light source being in the green range and one light source being in the blue range.
- the step of determining emission spectra of the individual LEDs or LED color groups from the measured spectrum of the generated light can include determining local minima or low points in the measured spectrum of the generated light.
- the measured spectrum is a superimposed spectrum, which consists of the emission spectra of the individual LEDs or LED color groups. Since different colors have different wavelengths, local minima in the common spectrum can correspond to transitions between individual emission spectra, that is to say start or end points of individual, overlaid emission spectra. Overall, the emission spectra of the individual LEDs or LED color groups can thus be derived in a simple manner from the measured spectrum.
- a regression analysis can be carried out for each of the emission spectra of the individual LEDs or LED color groups in order, for example, to supplement truncated spectrum ranges when determining the individual emission spectra.
- Regression analysis is a statistical technique for modeling relationships between different variables. It can be used, among other things, to describe and analyze relationships in data.
- control measurements can be carried out to verify the calculated tristium values.
- the calculated and stored values can be verified using a defined hue, for which a tolerance area can be specified, or with the participation of the achromatic point.
- the user receives feedback on the confidence or quality or the accuracy of the calculated values and in particular the determination of the emission spectra.
- the determined emission spectra can be confirmed, or the corresponding determination of the emission spectra be discarded again. This can then be repeated accordingly.
- other stored or specified data can also be used afterwards.
- the method can also include driving the LEDs or LED color groups of the LED lighting device with stored state variables, with the state variables being associated with stored tristimulus values compared with actual color values present after actuation with the state variables, with if a stored tristimulus value deviates from an actual color value , according to which a new tristimulus value is calculated and stored, ie the stored tristimulus value is updated accordingly.
- a recalibration or recalibration is carried out, which also takes aging processes into account, for example.
- a calibration device for calibrating color or photometric properties of an LED lighting device with LEDs or LED color groups emitting light of different colors or wavelengths, which emit light of the same color or wavelength within a color group, whose luminous flux components correspond to the light color , color temperature and/or the color locus of the light mixture emitted by the LED lighting device
- the calibration device has a first control unit, which is designed to control all LEDs or LED color groups in parallel in order to generate light, a spectrometer for measuring a spectrum of the light generated by parallel activation of all LEDs or LED color groups, a first computing unit, which is designed emission spectra of the individual LEDs or LED color groups from the measured spectrum of the light generated s, a second arithmetic unit, which is designed to calculate tristimulus values based on the individual emission spectra of the individual LEDs or LED case groups, and a memory for storing of the calculated tristimulus values in association with the known state variables.
- the calibration device is designed in such a way that the corresponding calibration method can be significantly accelerated and the time required for the corresponding calibration of the lighting devices can be reduced by approximately 40 to 50% in particular. Overall, an improved calibration device for calibrating color or photometric properties of an LED lighting device is thus specified.
- the first arithmetic unit has a bandpass filter, the first arithmetic unit being designed to determine the emission spectra of the individual LEDs or LED color groups by determining local minima in the measured spectrum of the light generated.
- a bandpass filter is understood to be a filter which only allows signals from one frequency band to pass.
- the measured spectrum is a superimposed spectrum composed of the emission spectra of the individual LEDs or LED color groups. Since different colors have different wavelengths, local minima or local low points in the common spectrum can correspond to transitions between individual emission spectra, ie start or end points of individual emission spectra that are superimposed. Overall, the calibration device can thus be designed in such a way that the emission spectra of the individual LEDs or Easily derive LED color groups from the measured spectrum.
- the calibration device can also have a third computing unit, which is designed to carry out a regression analysis for each of the emission spectra of the individual LEDs or LED color groups in order to supplement truncated spectrum ranges.
- a third computing unit which is designed to carry out a regression analysis for each of the emission spectra of the individual LEDs or LED color groups in order to supplement truncated spectrum ranges.
- truncated spectrum ranges can be added later, so that the accuracy when determining the individual emission spectra and thus also when calculating the tristimulus values can be increased.
- the calibration device can also further have a control device which is designed to carry out control measurements in order to verify the calculated tristimulus values.
- the control device can be designed to verify the calculated and stored values based on a defined hue, for which a tolerance range can be specified, or with the participation of the achromatic point.
- the user receives feedback on the confidence or quality or the accuracy of the calculated values and in particular the determination of the emission spectra. Based on this verification, for example, the determined emission spectra can be confirmed, or the corresponding determination of the emission spectra can be discarded again. This can then be repeated.
- other stored or specified data can then also be used.
- the calibration device can also have a second control unit, which is designed to control the LEDs or LED color groups of the LED lighting device with stored state variables, a comparator, which is designed to compare the stored tristimulus values assigned to the state variables with those that are actually present after the control with the state variables to compare color values, and an update unit which is designed to calculate a new tristimulus value in order to update a stored tristimulus value if this deviates from a corresponding color value that is actually present.
- the calibration device can thus also be designed in such a way that, in addition to the basic calibration, a recalibration or recalibration can also be carried out, which also takes account of aging processes, for example.
- a further embodiment of the invention also specifies a system for calibrating color or photometric properties of an LED lighting device, the system having a calibration device as described above and an LED lighting device with LEDs or LED color groups emitting light of different colors or wavelengths, which emit light of the same color or wavelength within a color group, the luminous flux components of which determine the light color, color temperature and/or the color locus of the light mixture emitted by the LED lighting device.
- a system which has an improved calibration device for calibrating color or photometric properties of an LED lighting device.
- the calibration device is characterized in that the first control unit is designed to control all LEDs or LED color groups in parallel, i.e. simultaneously, and not sequentially, with a spectrum of the generated light being recorded by the spectrometer, and with emission spectra of the individual LEDs or LEDs then being measured - Color groups are derived from this one spectrum, designed in such a way that the corresponding calibration method can be significantly accelerated and the time required for the corresponding calibration of the lighting devices can be reduced by approximately 40 to 50% in particular.
- the LED lighting device can have red, green and blue LEDs.
- light sources are used required, with one light source being in the red range, one light source being in the green range, and one light source being in the blue range.
- the present invention provides an improved method or an improved calibration device for calibrating color or photometric properties of an LED lighting device.
- the emission spectra of the individual LEDs or LED color groups can be derived in a simple manner from the measured spectrum, for example by determining local minima in the measured, common, superimposed spectrum.
- figure 1 shows a flowchart of a method 1 for calibrating color or photometric properties of an LED lighting device.
- the multicolored LED units usually include a number of single-color LEDs and are controlled with LED drivers which are designed to vary the brightness and the color location, ie the mixed color.
- the corresponding multi-color LED unit is usually calibrated.
- One or more color locations and/or brightnesses of the multicolored LED unit are specified and the individual LED chips are controlled sequentially, ie one after the other, in order to assign corresponding state variables, for example control signals.
- the color of a light source is generally further determined using a standard color table.
- This standard color chart is defined in the DIN 5033 standard or in the equivalent CIE 1931 standard, with a color being defined by an x and a y coordinate. Furthermore, all colors visible to a human being lie within a color triangle.
- the individual LED chips of the LED unit are usually driven sequentially, i.e. one after the other, corresponding emission spectra are recorded and the individual emission spectra are converted into a known color space, for example CIE 1931.
- tristimulus values (X,Y,Z), which indicate the corresponding proportions of the three primary colors red, green and blue, can be calculated.
- the calculated tristimulus values are then assigned to correspondingly present or predetermined state variables, for example the present electrical control or the corresponding control signal. the current temperature of the corresponding LED chip, etc. is saved in order to be able to control the individual LED chips accordingly in the future.
- figure 1 describes a method 1 for calibrating color or photometric properties of an LED lighting device with LEDs or LED color groups emitting light of different colors or wavelengths, which emit light of the same color or wavelength within a color group, whose luminous flux components determine the light color, color temperature and/or the determine the color locus of the light mixture emitted by the LED lighting device, with method 1 having the following steps: In a first step 2, all LEDs or LED color groups of the LED lighting structures are initially controlled in parallel with known state variables in order to generate light, in a second step 3, a spectrum of the light generated by parallel activation of all LEDs or LED color groups is measured, and in a third step 4, emission spectra of the individual LEDs or LED color groups from the measured spectrum of the generated L not to be determined. In a further step 5, tristimulus values are calculated based on the emission spectra of the individual LEDs or LED color groups, the calculated tristimulus values being stored in step 6 in association with the known state variables.
- the joint spectrum 2 is measured in accordance with the embodiments of FIG figure 1 based on a dispersive measurement principle, for example using an array spectrometer.
- Step 4 of determining emission spectra of the individual LEDs or LED color groups from the measured spectrum of the generated light includes determining local minima or low points in the measured spectrum of the generated light.
- the method 1 also has a step 7 of carrying out a regression analysis for each of the emission spectra of the individual LEDs or LED color groups in order, for example, to supplement truncated spectrum ranges when determining the individual emission spectra.
- Step 7 includes in particular a modeling of the spectrum normal distribution for each of the emission spectra using a regression analysis.
- Step 5 of calculating the tristimulus values also includes a determination of the corresponding CIE XYZ primary valences of the individual LEDs or LED color groups, whereby CIE 1931 or CIE 1964 can be used as a model system depending on the measurement principle or the application of the LED lighting device.
- a correction value matrix for the color mixture of the LED lighting device is then calculated, with the individual correction values relating to a model system then being able to be calculated based on a known reference system.
- the calculated tristimulus values are then stored in association with the known or existing specified state variables, for example in a controller of the LED lighting device, so that the LED lighting device can be controlled accordingly in the future.
- the method 1 also has a step 8 of carrying out control measurements in order to verify the calculated tristium values.
- the calculated and stored values can be verified using a defined hue, for which a tolerance area can be specified, or with the participation of the achromatic point.
- corresponding process monitoring systems can also be used for verification.
- verification can also be carried out using spectrometer factors.
- the method 1 also has a step 9 of a recalibration, wherein the LEDs or LED color groups of the LED lighting device are controlled with stored state variables, wherein the stored tristimulus values assigned to the state variables are compared with the actual color values present after the control with the state variables , and wherein if a stored tristimulus value deviates from an actual color value, a new tristimulus value is correspondingly calculated and stored.
- a recalibration or recalibration is carried out, which also takes aging processes into account, for example.
- all LEDs or LED color groups can be controlled in parallel. However, it is also possible to sequentially control all LEDs or LED color groups during the recalibration.
- figure 2 10 shows a block diagram of a system 10 for calibrating color or photometric properties of an LED lighting device according to embodiments of the invention.
- the system 10 has a calibration device for calibrating color or photometric properties of an LED lighting device 11 and an LED lighting device 12 with LEDs 13,14,15 emitting light of different colors or wavelengths whose luminous flux components determine the light color, color temperature and/or the color locus of the light mixture emitted by the LED lighting device 12.
- the LED lighting device has an LED 13 in the red range, an LED 14 in the green range and an LED 15 in the blue range. Overall, the LED lighting device thus has such light sources that it can emit light in all colors according to the CIE 1931 standard color chart.
- the calibration device 11 shown also has a, with an in figure 2 Not shown power supply connected first control unit 16, which is designed to control all LEDs 13,14,15 in parallel to generate light, a spectrometer 17 for measuring a spectrum of the light generated by parallel control of all LEDs 13,14,15, a first computing unit 18, which is designed to determine emission spectra of the individual LEDs 13,14,15 from the measured spectrum of the generated light, a second computing unit 19, which is designed to calculate tristimulus values based on the individual emission spectra of the individual LEDs 13,14,15, and a memory 20 for storing the calculated tristimulus values in association with the known state variables.
- first control unit 16 which is designed to control all LEDs 13,14,15 in parallel to generate light
- a spectrometer 17 for measuring a spectrum of the light generated by parallel control of all LEDs 13,14,15
- a first computing unit 18 which is designed to determine emission spectra of the individual LEDs 13,14,15 from the measured spectrum of the generated light
- the second computing unit is designed to use model systems, for example CIE 1931 or CIE 1964, during the calculation of the tristimulus values, depending on the measurement principle or LED application.
- model systems for example CIE 1931 or CIE 1964
- the first computing unit 18 can be, in particular, a computing unit on which code for determining emission spectra of the individual LEDs 13, 14, 15 from the measured spectrum of the generated light can be determined, stored and executed. It can be accordingly the second computing unit 19 is a computing unit on which code for calculating tristimulus values based on the individual emission spectra of the individual LEDs 13, 14, 15 is stored and can be executed.
- the first arithmetic unit 18 also has a bandpass filter 21, the first arithmetic unit 18 being designed to determine the emission spectra of the individual LEDs 13, 14, 15 by determining local minima in the measured spectrum of the light generated.
- a third computing unit 22 can also be seen, which is designed to carry out a regression analysis for each of the emission spectra of the individual LEDs 13, 14, 15 in order to supplement truncated spectrum ranges.
- the third arithmetic unit 22 is integrated into the first arithmetic unit 18 .
- the third processing unit can also be designed separately.
- the third computing unit 22 can again be a computing unit on which code for carrying out such a regression analysis is stored and can be executed.
- a control device 23 can also be seen, which is designed to carry out control measurements in order to verify the calculated tristimulus values.
- the calibration device 11 also has a second control unit 24, which is designed to control the LEDs 13,14,15 of the LED lighting device 12 with stored state variables, i.e. values for the state variable stored in the memory 20, a comparator 25, which is formed is to compare the stored tristimulus values assigned to the state variables with color values that are actually present after activation with the state variables, and an update unit 26 which is designed to calculate a new tristimulus value to update a stored tristimulus value if it deviates from a corresponding color value that is actually present.
- a second control unit 24 which is designed to control the LEDs 13,14,15 of the LED lighting device 12 with stored state variables, i.e. values for the state variable stored in the memory 20,
- a comparator 25 which is formed is to compare the stored tristimulus values assigned to the state variables with color values that are actually present after activation with the state variables
- an update unit 26 which is designed to calculate a new tristimulus value to update a stored tristimulus value
- the comparator 25 can in turn be a computing unit on which code for comparing the stored tristimulus values assigned to the state variables with color values actually present after activation with the state variables and measured via a spectrometer is stored and executable.
- the updating unit 26 can in turn be a computing unit on which code for calculating a new tristimulus value in order to update a stored tristimulus value if this deviates from a corresponding actually existing color value is stored and executable.
- the update unit 26 is designed in particular to overwrite the stored tristimulus value with the newly calculated tristimulus value, ie to now store the newly calculated tristimulus value in association with the present or specified state variables.
- the second control unit 24 is according to the embodiments of figure 2 further designed in such a way that all LEDs 13 , 14 , 15 are controlled in parallel again during this recalibration, the second control unit 24 being formed by the first control unit 16 .
- the second control unit can also be a separately formed control unit.
Abstract
Die Erfindung betrifft ein Verfahren zum Kalibrieren von farb- oder fotometrischen Eigenschaften einer LED-Beleuchtungseinrichtung mit Licht unterschiedlicher Farbe beziehungsweise Wellenlänge abstrahlenden LEDs oder LED-Farbgruppen, welche innerhalb einer Farbgruppe Licht derselben Farbe beziehungsweise Wellenlänge abstrahlen, deren Lichtstromanteile die Lichtfarbe, Farbtemperatur und/oder den Farbort der von der LED-Beleuchtungseinrichtung abgegebenen Lichtmischung bestimmen, wobei das Verfahren (1) folgende Schritte aufweist:- Paralleles Ansteuern aller LEDs oder LED-Farbgruppen der LED-Beleuchtungsstrukturen bei bekannten Zustandsgrößen, um Licht zu erzeugen (2);- Messen eines Spektrums des durch paralleles Ansteuern aller LEDs oder LED-Farbgruppen erzeugten Lichtes (3);- Ermitteln von Eimissionsspektren der einzelnen LEDs beziehungsweise LED-Farbgruppen aus dem gemessenen Spektrum des erzeugten Lichtes (4);- Berechnung von Tristimuluswerten basierend auf den Emissionsspektren der einzelnen LEDs beziehungsweise LED-Farbgruppen (5);- Speichern der berechneten Tristimuluswerte in Zuordnung zu den bekannten Zustandsgrößen (6).The invention relates to a method for calibrating color or photometric properties of an LED lighting device with LEDs or LED color groups emitting light of different colors or wavelengths, which emit light of the same color or wavelength within a color group, whose luminous flux components determine the light color, color temperature and/or determine the color locus of the light mixture emitted by the LED lighting device, the method (1) having the following steps: - parallel activation of all LEDs or LED color groups of the LED lighting structures with known state variables in order to generate light (2); - measuring a Spectrum of the light generated by parallel activation of all LEDs or LED color groups (3);- Determination of emission spectra of the individual LEDs or LED color groups from the measured spectrum of the light generated (4);- Calculation of tristimulus values based on the emission spectra of individual LEDs or LED color groups (5); - storing the calculated tristimulus values in association with the known state variables (6).
Description
Die vorliegende Erfindung betrifft ein Verfahren zum Kalibrieren von farb- oder fotometrischen Eigenschaften einer LED-Beleuchtungseinrichtung sowie eine entsprechende Kalibrierungsvorrichtung zum Kalibrieren von farb- oder fotometrischen Eigenschaften einer LED-Beleuchtungseinrichtung, mit welchen der erforderliche Zeitaufwand bei der Kalibrierung von farb- oder fotometrischen Eigenschaften einer LED-Beleuchtungseinrichtung erheblich reduziert werden kann.The present invention relates to a method for calibrating color or photometric properties of an LED lighting device and a corresponding calibration device for calibrating color or photometric properties of an LED lighting device, with which the time required for the calibration of color or photometric properties of a LED lighting device can be significantly reduced.
Es ist bekannt, für Beleuchtungseinrichtungen, beispielsweise Beleuchtungseinrichtungen in einem Kraftfahrzeug, mehrfarbige LED-Einheiten zu verwenden. Die mehrfarbigen LED-Einheiten umfassen dabei für gewöhnlich mehrere einfarbige LEDs und werden mit LED-Treibern angesteuert, welche ausgebildet sind, um die Helligkeit und den Farbort, das heißt die Mischfarbe, zu variieren.It is known to use multicolored LED units for lighting devices, for example lighting devices in a motor vehicle. In this case, the multicolored LED units usually include a number of single-color LEDs and are controlled with LED drivers which are designed to vary the brightness and the color location, ie the mixed color.
Um sicherzustellen, dass eine derartige mehrfarbige LED-Einheit Licht mit einer gewünschten Lichtfarbe aussendet, erfolgt für gewöhnlich eine Kalibrierung der entsprechenden mehrfarbigen LED-Einheit. Dabei werden ein oder mehrere Farborte und/oder Helligkeiten der mehrfarbigen LED-Einheit vorgegeben und werden die einzelnen LED-Chips sequenziell, das heißt nacheinander angesteuert, um entsprechende Zustandsgrößen, beispielsweise Ansteuersignale zuzuordnen.In order to ensure that such a multi-color LED unit emits light with a desired light color, the corresponding multi-color LED unit is usually calibrated. One or more color locations and/or brightnesses of the multicolored LED unit are specified and the individual LED chips are controlled sequentially, ie one after the other, in order to assign corresponding state variables, for example control signals.
Die Farbe einer Lichtquelle wird im Allgemeinen weiter über eine Normfarbtafel bestimmt. Diese Normfarbtafel ist in der Norm DIN 5033 oder in der äquivalenten Norm CIE 1931 definiert, wobei eine Farbe durch eine x- und eine y-Koordinate festgelegt wird. Weiter liegen alle für einen Menschen sichtbaren Farben innerhalb eines Farbdreiecks. Ein sogenannter Unbunt-Punkt ist ferner durch die Koordinaten x = 0,33 und y = 0,33 festgelegt, wobei Farben im Bereich um den Unbunt-Punkt allgemein als weiß empfunden werden. Während des Kalibrierens einer LED-Einheit, werden dabei für gewöhnlich die einzelnen LED-Chips der LED-Einheit sequentiell, das heißt nacheinander angesteuert, werden entsprechende Emissionssprektren erfasst, und werden die einzelnen Emissionsspektren in einen bekannten Farbraum, beispielsweise CIE 1931 umgerechnet. Insbesondere können dabei sogenannte Tristimuluswerte (X,Y,Z), welche die entsprechenden Anteile der drei Grundfarben Rot, Grün und Blau angeben, berechnet werden. Die berechneten Tristimuluswerte werden dann in Zuordnung zu entsprechend vorliegenden beziehungsweise vorgegebenen Zustandsgrößen, beispielsweise der vorliegenden elektrischen Ansteuerung beziehungsweise des entsprechenden Ansteuersignals, der vorliegenden Temperatur des entsprechenden LED-Chips, etc. abgespeichert, um die einzelnen LED-Chips zukünftig entsprechend ansteuern zu können.The color of a light source is generally further determined using a standard color table. This standard color chart is defined in the DIN 5033 standard or in the equivalent CIE 1931 standard, with a color being defined by an x and a y coordinate. Furthermore, all colors visible to a human being lie within a color triangle. A so-called achromatic point is also defined by the coordinates x=0.33 and y=0.33, with colors in the area around the achromatic point generally being perceived as white. During the calibration of an LED unit, the individual LED chips of the LED unit are usually calibrated corresponding emission spectra are recorded sequentially, that is to say controlled one after the other, and the individual emission spectra are converted into a known color space, for example CIE 1931. In particular, so-called tristimulus values (X,Y,Z), which indicate the corresponding proportions of the three primary colors red, green and blue, can be calculated. The calculated tristimulus values are then stored in association with correspondingly existing or predetermined state variables, for example the existing electrical control or the corresponding control signal, the current temperature of the corresponding LED chip, etc., in order to be able to control the individual LED chips accordingly in the future.
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Aufgabe von Ausführungsformen der Erfindung ist es, ein verbessertes Verfahren beziehungsweise eine verbesserte Kalibrierungsvorrichtung zum Kalibrieren von farb- oder fotometrischen Eigenschaften einer LED-Beleuchtungseinrichtung anzugeben.The object of embodiments of the invention is to specify an improved method or an improved calibration device for calibrating color or photometric properties of an LED lighting device.
Gelöst wird diese Aufgabe durch den Gegenstand der nebengeordneten Ansprüche. Vorteilhafte Weiterbildungen sind Gegenstand der abhängigen Ansprüche.This problem is solved by the subject matter of the independent claims. Advantageous developments are the subject of the dependent claims.
Gemäß einer Ausführungsform der Erfindung wird diese Aufgabe gelöst durch ein Verfahren zum Kalibrieren von farb- oder fotometrischen Eigenschaften einer LED-Beleuchtungseinrichtung mit Licht unterschiedlicher Farbe beziehungsweise Wellenlänge abstrahlenden LEDs oder LED-Farbgruppen, welche innerhalb einer Farbgruppe Licht derselben Farbe beziehungsweise Wellenlänge abstrahlen, deren Lichtstromanteile die Lichtfarbe, Farbtemperatur und/oder den Farbort der von der LED-Beleuchtungseinrichtung abgegebenen Lichtmischung bestimmen, wobei das Verfahren folgende Schritte aufweist: So werden zunächst alle LEDs oder LED-Farbgruppen der LED-Beleuchtungsstrukturen bei bekannten Zustandsgrößen parallel angesteuert, um Licht zu erzeugen, wobei ein Spektrums des durch paralleles Ansteuern aller LEDs oder LED-Farbgruppen erzeugten Lichtes gemessen wird, und wobei Emissionsspektren der einzelnen LEDs beziehungsweise LED-Farbgruppen aus dem gemessenen Spektrum des erzeugten Lichtes ermittelt werden. Anschließend werden Tristimuluswerte basierend auf den Emissionsspektren der einzelnen LEDs beziehungsweise LED-Farbgruppen berechnet, wobei die berechneten Tristimuluswerte in Zuordnung zu den bekannten Zustandsgrößen abgespeichert werden.According to one embodiment of the invention, this object is achieved by a method for calibrating color or photometric properties of an LED lighting device with LEDs or LED color groups emitting light of different colors or wavelengths, which emit light of the same color or wavelength within a color group, whose luminous flux components determine the light color, color temperature and/or the color locus of the light mixture emitted by the LED lighting device, the method having the following steps: First, all LEDs or LED color groups of the LED lighting structures are controlled in parallel with known state variables in order to generate light, wherein a spectrum of the light generated by driving all LEDs or LED color groups in parallel is measured, and wherein emission spectra of the individual LEDs or LED color groups are determined from the measured spectrum of the light generated. Subsequently, tristimulus values are calculated based on the emission spectra of the individual LEDs or LED color groups, the calculated tristimulus values being stored in association with the known state variables.
Unter parallelen Ansteuern wird hierbei verstanden, dass die einzelnen LEDs beziehungsweise LED-Farbgruppen nicht sequentiell, sondern zeitgleich beziehungsweise alle gemeinsam angesteuert werden.Parallel activation is understood here to mean that the individual LEDs or LED color groups are not activated sequentially but at the same time or all together.
Unter Spektrum beziehungsweise elektromagnetischem Spektrum wird weiter allgemein die Gesamtheit aller elektromagnetischer Wellen verschiedener Wellenlängen verstanden, wobei das Lichtspektrum beziehungsweise Farbspektrum den für einen Menschen sichtbaren Bereich des elektromagnetischen Spektrums darstellt. Spektren, welche alleine durch das Licht entstehen, welches durch eine Lichtquelle ausgesendet wird, werden ferner als Emissionsspektren bezeichnet.The spectrum or electromagnetic spectrum is also generally understood to mean the entirety of all electromagnetic waves of different wavelengths, with the light spectrum or color spectrum representing the range of the electromagnetic spectrum that is visible to a human being. Spectra that arise solely from the light that is emitted by a light source are also referred to as emission spectra.
Bei den farb- oder fotometrischen Eigenschaften kann es sich ferner beispielsweise um ein Farb-/Helligkeits-Mischverhältnis handeln.The color or photometric properties can also be a color/brightness mixing ratio, for example.
Dadurch, dass alle LEDs beziehungsweise LED-Farbgruppen parallel, das heißt gleichzeitig, und nicht sequentiell angesteuert werden, wobei ein Spektrum des erzeugten Lichtes erfasst, und wobei anschließend Emissionsspektren der einzelnen Leds beziehungsweise LED-Farbgruppen aus diesem einem Spektrum abgeleitet werden, kann das Kalibrierungsverfahren erheblich beschleunigt werden und die zum entsprechenden Kalibrieren der Beleuchtungseinrichtungen benötigte Zeit insbesondere um circa 40 bis 50% verkürzt werden. Insgesamt wird somit ein verbessertes Verfahren zum Kalibrieren von farb- oder fotometrischen Eigenschaften einer LED-Beleuchtungseinrichtung angegeben.The fact that all LEDs or LED color groups are controlled in parallel, i.e. simultaneously, and not sequentially, with a spectrum of the generated light being recorded, and emission spectra of the individual LEDs or LED color groups then being derived from this one spectrum, allows the calibration method can be accelerated considerably and the time required for the corresponding calibration of the lighting devices can be reduced by around 40 to 50% in particular. Overall, an improved method for calibrating color or photometric properties of an LED lighting device is thus specified.
Die LED-Beleuchtungseinrichtung kann dabei insbesondere rote, grüne und blaue LEDs aufweisen. So sind, um eine Beleuchtungseinrichtung, welche Licht in allen Farben gemäß der Normfarbtafel CIE 1931 abstrahlen kann, bereitzustellen, Lichtquellen erforderlich, wobei eine Lichtquelle im roten Bereich liegt, eine Lichtquelle im grünen Bereich liegt und eine Lichtquelle im blauen Bereich liegt.The LED lighting device can in particular have red, green and blue LEDs. Thus, in order to provide a lighting device which can emit light in all colors according to the CIE 1931 chromaticity diagram, light sources are required, with one light source being in the red range, one light source being in the green range and one light source being in the blue range.
Zudem kann der Schritt des Ermittelns von Emissionsspektren der einzelnen LEDs beziehungsweise LED-Farbgruppen aus dem gemessenen Spektrum des erzeugten Lichtes ein Ermitteln lokaler Minima beziehungsweise Tiefpunkte in dem gemessenen Spektrum des erzeugten Lichtes aufweisen. So handelt es sich bei dem gemessenen Spektrum um ein überlagertes Spektrum, welches sich aus den Emissionsspektren der einzelnen LEDs beziehungsweise LED-Farbgruppen zusammensetzt. Da unterschiedliche Farben unterschiedliche Wellenlängen aufweisen, können lokale Minima in dem gemeinsamen Spektrum Übergängen zwischen einzelnen Emissionsspektren, das heißt Anfangs- beziehungsweise Endpunkte einzelner der überlagerten Emissionsspektren entsprechen. Insgesamt können die Emissionsspektren der einzelnen LEDs beziehungsweise LED-Farbgruppen somit auf einfache Art und Weise aus dem gemessenen Spektrum abgeleitet werden.In addition, the step of determining emission spectra of the individual LEDs or LED color groups from the measured spectrum of the generated light can include determining local minima or low points in the measured spectrum of the generated light. The measured spectrum is a superimposed spectrum, which consists of the emission spectra of the individual LEDs or LED color groups. Since different colors have different wavelengths, local minima in the common spectrum can correspond to transitions between individual emission spectra, that is to say start or end points of individual, overlaid emission spectra. Overall, the emission spectra of the individual LEDs or LED color groups can thus be derived in a simple manner from the measured spectrum.
Zudem kann für jedes der Emissionsspektrum der einzelnen LEDs oder LED-Farbgruppen eine Regressionsanalyse durchgeführt werden, um, beispielsweise beim Ermitteln der einzelnen Emissionsspektren abgeschnittene Spektrumsbereiche zu ergänzen.In addition, a regression analysis can be carried out for each of the emission spectra of the individual LEDs or LED color groups in order, for example, to supplement truncated spectrum ranges when determining the individual emission spectra.
Die Regressionsanalyse ist ein statistisches Verfahren zur Modellierung von Beziehungen zwischen unterschiedlichen Variablen. Sie kann unter anderem dazu verwendet werden, um Zusammenhänge in Daten zu beschreiben und zu analysieren.Regression analysis is a statistical technique for modeling relationships between different variables. It can be used, among other things, to describe and analyze relationships in data.
Hierdurch können abgeschnittene Spektrumsbereiche nachträglich ergänzt werden, so dass die Genauigkeit bei der Ermittlung der einzelnen Emissionsspektren und somit auch beim Berechnen der Tristimuluswerte erhöht werden kann.In this way, truncated spectrum ranges can be added later, so that the accuracy when determining the individual emission spectra and thus also when calculating the tristimulus values can be increased.
Ferner können Kontrollmessungen durchgeführt werden, um die berechneten Tristiumuswerte zu verifizieren. Beispielsweise können die berechneten und gespeicherten Werte anhand eines definierten Farbtones, für welchen ein Toleranzgebiet vorgegeben sein kann, beziehungsweise unter Beteiligung des Unbunt-Punktes verifiziert werden. Anhand der Verifizierung erhält der Nutzer eine Rückmeldung über die Konfidenz beziehungsweise Güte oder die Genauigkeit der berechneten Werte und insbesondere der Ermittlung der Emissionsspektren. Basierend auf dieser Verifizierung können dabei beispielsweise die ermittelten Emissionsspektren bestätigt werden, oder auch die entsprechende Ermittlung der Emissionsspektren wieder verworfen werden. Diese kann dann entsprechend wiederholt werden. Ferner können anschließend, aber auch andere abgespeicherte beziehungsweise vorgegebenen Daten herangezogen werden.Furthermore, control measurements can be carried out to verify the calculated tristium values. For example, the calculated and stored values can be verified using a defined hue, for which a tolerance area can be specified, or with the participation of the achromatic point. Based on the verification, the user receives feedback on the confidence or quality or the accuracy of the calculated values and in particular the determination of the emission spectra. Based on this verification, for example, the determined emission spectra can be confirmed, or the corresponding determination of the emission spectra be discarded again. This can then be repeated accordingly. Furthermore, other stored or specified data can also be used afterwards.
Zudem kann das Verfahren weiter ein Ansteuern der LEDs oder LED-Farbgruppen der LED-Beleuchtungseinrichtung mit abgespeicherten Zustandsgrößen aufweisen, wobei den Zustandsgrößen zugeordneten abgespeicherten Tristimuluswerte mit nach Ansteuerung mit den Zustandsgrößen vorliegenden tatsächlichen Farbwerten verglichen werden, wobei falls ein abgespeicherter Tristimuluswert von einem tatsächlichen Farbwert abweicht, entsprechend ein neuer Tristimuluswert berechnet und abgespeichert wird, das heißt der abgespeicherte Tristimuluswert entsprechend aktualisiert wird. Somit wird zusätzlich zur Grundkalibration noch eine Nach- beziehungsweise Neukalibration durchgeführt, welche beispielsweise auch Alterungsprozessen Rechnung trägt.In addition, the method can also include driving the LEDs or LED color groups of the LED lighting device with stored state variables, with the state variables being associated with stored tristimulus values compared with actual color values present after actuation with the state variables, with if a stored tristimulus value deviates from an actual color value , according to which a new tristimulus value is calculated and stored, ie the stored tristimulus value is updated accordingly. Thus, in addition to the basic calibration, a recalibration or recalibration is carried out, which also takes aging processes into account, for example.
Mit einer weiteren Ausführungsform der Erfindung wird auch eine Kalibrierungsvorrichtung zum Kalibrieren von farb- oder fotometrischen Eigenschaften einer LED-Beleuchtungseinrichtung mit Licht unterschiedlicher Farbe beziehungsweise Wellenlänge abstrahlenden LEDs oder LED-Farbgruppen, welche innerhalb einer Farbgruppe Licht derselben Farbe beziehungsweise Wellenlänge abstrahlen, deren Lichtstromanteile die Lichtfarbe, Farbtemperatur und/oder den Farbort der von der LED-Beleuchtungseinrichtung abgegebenen Lichtmischung bestimmen, angegeben, wobei die Kalibrierungsvorrichtung eine erste Ansteuereinheit, welche ausgebildet ist alle LEDs oder LED-Farbgruppen parallel anzusteuern, um Licht zu erzeugen, einen Spektrometer zum Messen eines Spektrums des durch paralleles Ansteuern aller LEDs oder LED-Farbgruppen erzeugten Lichtes, eine erste Recheneinheit, welche ausgebildet ist Emissionsspektren der einzelnen LEDs beziehungsweise LED-Farbgruppen aus dem gemessenen Spektrum des erzeugten Lichts zu ermitteln, eine zweite Recheneinheit, welche ausgebildet ist Tristimuluswerte basierend auf den einzelnen Emissionsspektren der einzelnen LEDs beziehungsweise LED-Fallgruppen zu berechnen, und einen Speicher zum Speichern der berechneten Tristimuluswerte in Zuordnung zu den bekannten Zustandsgrößen aufweist.With a further embodiment of the invention, a calibration device for calibrating color or photometric properties of an LED lighting device with LEDs or LED color groups emitting light of different colors or wavelengths, which emit light of the same color or wavelength within a color group, whose luminous flux components correspond to the light color , color temperature and/or the color locus of the light mixture emitted by the LED lighting device, where the calibration device has a first control unit, which is designed to control all LEDs or LED color groups in parallel in order to generate light, a spectrometer for measuring a spectrum of the light generated by parallel activation of all LEDs or LED color groups, a first computing unit, which is designed emission spectra of the individual LEDs or LED color groups from the measured spectrum of the light generated s, a second arithmetic unit, which is designed to calculate tristimulus values based on the individual emission spectra of the individual LEDs or LED case groups, and a memory for storing of the calculated tristimulus values in association with the known state variables.
Dadurch, dass die erste Ansteuereinheit ausgebildet ist, alle LEDs beziehungsweise LED-Farbgruppen parallel, das heißt gleichzeitig, und nicht sequentiell anzusteuern, wobei ein Spektrum des erzeugten Lichtes durch den Spektrometer erfasst, und wobei anschließend Emissionsspektren der einzelnen LEDs beziehungsweise LED-Farbgruppen aus diesem einem Spektrum abgeleitet werden, ist die Kalibrierungsvorrichtung derart ausgebildet, dass das entsprechende Kalibrierungsverfahren erheblich beschleunigt werden und die zum entsprechenden Kalibrieren der Beleuchtungseinrichtungen benötigte Zeit insbesondere um circa 40 bis 50% verkürzt werden kann. Insgesamt wird somit eine verbessertes Kalibrierungsvorrichtung zum Kalibrieren von farb- oder fotometrischen Eigenschaften einer LED-Beleuchtungseinrichtung angegeben.The fact that the first control unit is designed to control all LEDs or LED color groups in parallel, i.e. simultaneously, and not sequentially, with a spectrum of the generated light being recorded by the spectrometer, and emission spectra of the individual LEDs or LED color groups then being recorded from this are derived from a spectrum, the calibration device is designed in such a way that the corresponding calibration method can be significantly accelerated and the time required for the corresponding calibration of the lighting devices can be reduced by approximately 40 to 50% in particular. Overall, an improved calibration device for calibrating color or photometric properties of an LED lighting device is thus specified.
In einer Ausführungsform weist die erste Recheneinheit ein Bandpassfilter auf, wobei die erste Recheneinheit ausgebildet ist, die Emissionsspektren der einzelnen LEDs beziehungsweise LED-Farbgruppen durch Ermitteln lokaler Minima in dem gemessenen Spektrum des erzeugten Lichtes zu ermitteln.In one embodiment, the first arithmetic unit has a bandpass filter, the first arithmetic unit being designed to determine the emission spectra of the individual LEDs or LED color groups by determining local minima in the measured spectrum of the light generated.
Unter Bandpassfilter wird hierbei ein Filter verstanden, welches nur Signale eines Frequenzbandes passieren lässt.A bandpass filter is understood to be a filter which only allows signals from one frequency band to pass.
So handelt es sich bei dem gemessenen Spektrum um ein überlagertes Spektrum, welches sich aus den Emissionsspektren der einzelnen LEDs beziehungsweise LED-Farbgruppen zusammensetzt. Da unterschiedliche Farben unterschiedliche Wellenlängen aufweisen, können lokale Minima beziehungsweise lokale Tiefpunkte in dem gemeinsamen Spektrum Übergängen zwischen einzelnen Emissionsspektren, das heißt Anfangs- beziehungsweise Endpunkte einzelner der überlagerten Emissionsspektren entsprechen. Insgesamt kann die Kalibrierungsvorrichtung somit derart ausgebildet sein, die Emissionsspektren der einzelnen LEDs beziehungsweise LED-Farbgruppen auf einfache Art und Weise aus dem gemessenen Spektrum abzuleiten.The measured spectrum is a superimposed spectrum composed of the emission spectra of the individual LEDs or LED color groups. Since different colors have different wavelengths, local minima or local low points in the common spectrum can correspond to transitions between individual emission spectra, ie start or end points of individual emission spectra that are superimposed. Overall, the calibration device can thus be designed in such a way that the emission spectra of the individual LEDs or Easily derive LED color groups from the measured spectrum.
Zudem kann die Kalibrierungsvorrichtung weiter eine dritte Recheneinheit, welche ausgebildet ist für jedes der Emissionsspektren der einzelnen LEDs beziehungsweise LED-Farbgruppen eine Regressionsanalyse durchzuführen, um abgeschnittene Spektrumsbereiche zu ergänzen, aufweisen. Hierdurch können abgeschnittene Spektrumsbereiche nachträglich ergänzt werden, so dass die Genauigkeit bei der Ermittlung der einzelnen Emissionsspektren und somit auch beim Berechnen der Tristimuluswerte erhöht werden kann.In addition, the calibration device can also have a third computing unit, which is designed to carry out a regression analysis for each of the emission spectra of the individual LEDs or LED color groups in order to supplement truncated spectrum ranges. In this way, truncated spectrum ranges can be added later, so that the accuracy when determining the individual emission spectra and thus also when calculating the tristimulus values can be increased.
Auch kann die Kalibrierungsvorrichtung weiter eine Kontrolleinrichtung, welche ausgebildet ist, Kontrollmessungen durchzuführen, um die berechneten Tristimuluswerte zu verifizieren, aufweisen. Beispielsweise kann die Kontrolleinrichtung dabei ausgebildet sein, die berechneten und gespeicherten Werte anhand eines definierten Farbtones, für welchen ein Toleranzgebiet vorgegeben sein kann, beziehungsweise unter Beteiligung des Unbunt-Punktes zu verifizieren. Anhand der Verifizierung erhält der Nutzer eine Rückmeldung über die Konfidenz beziehungsweise Güte oder die Genauigkeit der berechneten Werte und insbesondere der Ermittlung der Emissionsspektren. Basierend auf dieser Verifizierung können dabei beispielsweise die ermittelten Emissionsspektren bestätigt werden, oder auch die entsprechende Ermittlung der Emissionsspektren wieder verworfen werden. Diese kann dann wiederholt werden. Ferner können anschließend aber auch andere abgespeicherte beziehungsweise vorgegebenen Daten herangezogen werden.The calibration device can also further have a control device which is designed to carry out control measurements in order to verify the calculated tristimulus values. For example, the control device can be designed to verify the calculated and stored values based on a defined hue, for which a tolerance range can be specified, or with the participation of the achromatic point. Based on the verification, the user receives feedback on the confidence or quality or the accuracy of the calculated values and in particular the determination of the emission spectra. Based on this verification, for example, the determined emission spectra can be confirmed, or the corresponding determination of the emission spectra can be discarded again. This can then be repeated. In addition, however, other stored or specified data can then also be used.
Zudem kann die Kalibrierungsvorrichtung weiter eine zweite Ansteuereinheit, welche ausgebildet ist, die LEDs oder LED-Farbgruppen der LED-Beleuchtungseinrichtung mit abgespeicherten Zustandsgrößen anzusteuern, einen Vergleicher, welcher ausgebildet ist, der den Zustandsgrößen zugeordnete abgespeicherte Tristimuluswerte mit nach der Ansteuerung mit den Zustandsgrößen tatsächlich vorliegenden Farbwerten zu vergleichen, und eine Aktualisierungseinheit, welche ausgebildet ist, einen neuen Tristimulswert zu berechnen um einen gespeicherten Tristimuluswert zu aktualisieren, falls dieser von einem entsprechenden tatsächlich vorliegenden Farbwert abweicht. Somit kann die Kalibrierungsvorrichtung auch derart ausgebildet sein, zusätzlich zur Grundkalibration noch eine Nach- beziehungsweise Neukalibration durchzuführen, welche beispielsweise auch Alterungsprozessen Rechnung trägt.In addition, the calibration device can also have a second control unit, which is designed to control the LEDs or LED color groups of the LED lighting device with stored state variables, a comparator, which is designed to compare the stored tristimulus values assigned to the state variables with those that are actually present after the control with the state variables to compare color values, and an update unit which is designed to calculate a new tristimulus value in order to update a stored tristimulus value if this deviates from a corresponding color value that is actually present. The calibration device can thus also be designed in such a way that, in addition to the basic calibration, a recalibration or recalibration can also be carried out, which also takes account of aging processes, for example.
Mit einer weiteren Ausführungsform der Erfindung wird ferner auch ein System zum Kalibrieren von farb- oder fotometrischen Eigenschaften einer LED-Beleuchtungseinrichtung angegeben, wobei das System eine oben beschriebene Kalibrierungsvorrichtung und eine LED-Beleuchtungseinrichtung mit Licht unterschiedlicher Farbe beziehungsweise Wellenlänge abstrahlenden LEDs oder LED-Farbgruppen, welche innerhalb einer Farbgruppe Licht derselben Farbe beziehungsweise Wellenlänge abstrahlen, deren Lichtstromanteile die Lichtfarbe, Farbtemperatur und/oder den Farbort der von der LED-Beleuchtungseinrichtung abgegebenen Lichtmischung bestimmen, aufweist.A further embodiment of the invention also specifies a system for calibrating color or photometric properties of an LED lighting device, the system having a calibration device as described above and an LED lighting device with LEDs or LED color groups emitting light of different colors or wavelengths, which emit light of the same color or wavelength within a color group, the luminous flux components of which determine the light color, color temperature and/or the color locus of the light mixture emitted by the LED lighting device.
Somit wird ein System angegebene, welches eine verbesserte Kalibrierungsvorrichtung zum Kalibrieren von farb- oder fotometrischen Eigenschaften einer LED-Beleuchtungseinrichtung aufweist. So ist die Kalibrierungsvorrichtung dadurch, dass die erste Ansteuereinheit ausgebildet ist, alle LEDs beziehungsweise LED-Farbgruppen parallel, das heißt gleichzeitig, und nicht sequentiell anzusteuern, wobei ein Spektrum des erzeugten Lichtes durch den Spektrometer erfasst, und wobei anschließend Emissionsspektren der einzelnen LEDs beziehungsweise LED-Farbgruppen aus diesem einem Spektrum abgeleitet werden, derart ausgebildet, dass das entsprechende Kalibrierungsverfahren erheblich beschleunigt werden und die zum entsprechenden Kalibrieren der Beleuchtungseinrichtungen benötigte Zeit insbesondere um circa 40 bis 50% verkürzt werden kann.A system is thus specified which has an improved calibration device for calibrating color or photometric properties of an LED lighting device. The calibration device is characterized in that the first control unit is designed to control all LEDs or LED color groups in parallel, i.e. simultaneously, and not sequentially, with a spectrum of the generated light being recorded by the spectrometer, and with emission spectra of the individual LEDs or LEDs then being measured - Color groups are derived from this one spectrum, designed in such a way that the corresponding calibration method can be significantly accelerated and the time required for the corresponding calibration of the lighting devices can be reduced by approximately 40 to 50% in particular.
Insbesondere kann die LED-Beleuchtungseinrichtung rote, grüne und blaue LEDs aufweisen. So sind, um eine Beleuchtungseinrichtung, welche Licht in allen Farben gemäß der Normfarbtafel CIE 1931 abstrahlen kann, bereitzustellen, Lichtquellen erforderlich, wobei eine Lichtquelle im roten Bereich liegt, eine Lichtquelle im grünen Bereich liegt und eine Lichtquelle im blauen Bereich liegt.In particular, the LED lighting device can have red, green and blue LEDs. Thus, in order to provide a lighting device which can emit light in all colors according to the CIE 1931 standard color table, light sources are used required, with one light source being in the red range, one light source being in the green range, and one light source being in the blue range.
Zusammenfassend ist festzustellen, dass mit der vorliegenden Erfindung ein verbessertes Verfahren beziehungsweise eine verbesserte Kalibrierungsvorrichtung zum Kalibrieren von farb- oder fotometrischen Eigenschaften einer LED-Beleuchtungseinrichtung angegeben werden.In summary, it can be stated that the present invention provides an improved method or an improved calibration device for calibrating color or photometric properties of an LED lighting device.
Insbesondere kann dadurch, dass alle LEDs beziehungsweise LED-Farbgruppen parallel, das heißt gleichzeitig, und nicht sequentiell angesteuert werden, wobei ein Spektrum des erzeugten Lichtes erfasst, und wobei anschließend Emissionsspektren der einzelnen Leds beziehungsweise LED-Farbgruppen aus diesem einem Spektrum abgeleitet werden, das Kalibrierungsverfahren erheblich beschleunigt werden und die zum entsprechenden Kalibrieren der Beleuchtungseinrichtungen benötigte Zeit insbesondere um circa 40 bis 50% verkürzt werden.In particular, the fact that all LEDs or LED color groups are controlled in parallel, i.e. simultaneously, and not sequentially, with a spectrum of the generated light being recorded, and emission spectra of the individual LEDs or LED color groups then being derived from this one spectrum Calibration methods are significantly accelerated and the time required for the corresponding calibration of the lighting devices can be reduced by about 40 to 50% in particular.
Dabei können die Emissionsspektren der einzelnen LEDs beziehungsweise LED-Farbgruppen beispielsweise durch Ermitteln von lokalen Minima in dem gemessenen, gemeinsamen, überlagerten Spektrum auf einfache Art und Weise aus dem gemessenen Spektrum abgeleitet werden.The emission spectra of the individual LEDs or LED color groups can be derived in a simple manner from the measured spectrum, for example by determining local minima in the measured, common, superimposed spectrum.
Die Erfindung wird nun anhand der beigefügten Figuren näher erläutert.
Figur 1- zeigt ein Flussdiagramm eines Verfahrens zum Kalibrieren von farb- oder fotometrischen Eigenschaften einer LED-Beleuchtungseinrichtung gemäß Ausführungsformen der Erfindung;
Figur 2- zeigt ein Blockschaltbild eines Systems zum Kalibrieren von farb- oder fotometrischen Eigenschaften einer LED-Beleuchtungseinrichtung gemäß Ausführungsformen der Erfindung.
- figure 1
- 12 shows a flow chart of a method for calibrating color or photometric properties of an LED lighting device according to embodiments of the invention;
- figure 2
- FIG. 12 shows a block diagram of a system for calibrating color or photometric properties of an LED lighting device according to embodiments of the invention.
Es ist bekannt, für Beleuchtungseinrichtungen, beispielsweise Beleuchtungseinrichtungen in einem Kraftfahrzeug, mehrfarbige LED-Einheiten zu verwenden. Die mehrfarbigen LED-Einheiten umfassen dabei für gewöhnlich mehrere einfarbige LEDs und werden mit LED-Treibern angesteuert, welche ausgebildet sind, um die Helligkeit und den Farbort, das heißt die Mischfarbe, zu variieren.It is known to use multicolored LED units for lighting devices, for example lighting devices in a motor vehicle. In this case, the multicolored LED units usually include a number of single-color LEDs and are controlled with LED drivers which are designed to vary the brightness and the color location, ie the mixed color.
Um sicherzustellen, dass eine derartige mehrfarbige LED-Einheit Licht mit einer gewünschten Lichtfarbe aussendet, erfolgt für gewöhnlich eine Kalibrierung der entsprechenden mehrfarbigen LED-Einheit. Dabei werden ein oder mehrere Farborte und/oder Helligkeiten der mehrfarbigen LED-Einheit vorgegeben und werden die einzelnen LED-Chips sequentiell, das heißt nacheinander angesteuert, um entsprechende Zustandsgrößen, beispielsweise Ansteuersignale zuzuordnen.In order to ensure that such a multi-color LED unit emits light with a desired light color, the corresponding multi-color LED unit is usually calibrated. One or more color locations and/or brightnesses of the multicolored LED unit are specified and the individual LED chips are controlled sequentially, ie one after the other, in order to assign corresponding state variables, for example control signals.
Die Farbe einer Lichtquelle wird im Allgemeinen weiter über eine Normfarbtafel bestimmt. Diese Normfarbtafel ist in der Norm DIN 5033 oder in der äquivalenten Norm CIE 1931 definiert, wobei eine Farbe durch eine x- und eine y-Koordinate festgelegt wird. Weiter liegen alle für einen Menschen sichtbaren Farben innerhalb eines Farbdreiecks. Ein sogenannter Unbunt-Punkt ist ferner durch die Koordinaten x = 0,33 und y = 0,33 festgelegt, wobei Farben im Bereich um den Unbunt-Punkt allgemein als weiß empfunden werden. Während des Kalibrierens einer LED-Einheit, werden dabei für gewöhnlich die einzelnen LED-Chips der LED-Einheit sequentiell, das heißt nacheinander angesteuert, werden entsprechende Emissionsspektren erfasst, und werden die einzelnen Emissionsspektren in einen bekannten Farbraum, beispielsweise CIE 1931 umgerechnet. Insbesondere können dabei sogenannte Tristimuluswerte (X,Y,Z), welche die entsprechenden Anteile der drei Grundfarben Rot, Grün und Blau angeben, berechnet werden. Die berechneten Tristimuluswerte werden dann in Zuordnung zu entsprechend vorliegenden beziehungsweise vorgegebenen Zustandsgrößen, beispielsweise der vorliegenden elektrischen Ansteuerung beziehungsweise des entsprechenden Ansteuersignals, der vorliegenden Temperatur des entsprechenden LED-Chips, etc. abgespeichert, um die einzelnen LED-Chips zukünftig entsprechend ansteuern zu können.The color of a light source is generally further determined using a standard color table. This standard color chart is defined in the DIN 5033 standard or in the equivalent CIE 1931 standard, with a color being defined by an x and a y coordinate. Furthermore, all colors visible to a human being lie within a color triangle. A so-called achromatic point is also defined by the coordinates x=0.33 and y=0.33, with colors in the area around the achromatic point generally being perceived as white. During the calibration of an LED unit, the individual LED chips of the LED unit are usually driven sequentially, i.e. one after the other, corresponding emission spectra are recorded and the individual emission spectra are converted into a known color space, for example CIE 1931. In particular, so-called tristimulus values (X,Y,Z), which indicate the corresponding proportions of the three primary colors red, green and blue, can be calculated. The calculated tristimulus values are then assigned to correspondingly present or predetermined state variables, for example the present electrical control or the corresponding control signal. the current temperature of the corresponding LED chip, etc. is saved in order to be able to control the individual LED chips accordingly in the future.
Gemäß den Ausführungsformen der
Dadurch, dass alle LEDs beziehungsweise LED-Farbgruppen parallel, das heißt gleichzeitig, und nicht sequentiell angesteuert werden, wobei ein Spektrum des erzeugten Lichtes erfasst, und wobei anschließend Emissionsspektren der einzelnen Leds beziehungsweise LED-Farbgruppen aus diesem einem Spektrum abgeleitet werden, kann das Kalibrierungsverfahren erheblich beschleunigt werden und die zum entsprechenden Kalibrieren der Beleuchtungseinrichtungen benötigte Zeit insbesondere um circa 40 bis 50% verkürzt werden. Insgesamt wird somit ein verbessertes Verfahren 1 zum Kalibrieren von farb- oder fotometrischen Eigenschaften einer LED-Beleuchtungseinrichtung angegeben.The fact that all LEDs or LED color groups are controlled in parallel, i.e. simultaneously, and not sequentially, with a spectrum of the generated light being recorded, and emission spectra of the individual LEDs or LED color groups then being derived from this one spectrum, allows the calibration method can be accelerated considerably and the time required for the corresponding calibration of the lighting devices can be reduced by around 40 to 50% in particular. Overall, an
Das Messen des gemeinsamen Spektrums 2 erfolgt dabei gemäß den Ausführungsformen der
Gemäß den Ausführungsformen der
Wie
Gemäß den Ausführungsformen der
Die berechneten Tristimuluswerte werden anschließend in Zuordnung zu den bekannten beziehungsweise vorliegenden vorgegebenen Zustandsgrößen abgespeichert, beispielsweise in einem Controller der LED-Beleuchtungseinrichtung, sodass die LED-Beleuchtungseinrichtung zukünftig entsprechend angesteuert werden kann.The calculated tristimulus values are then stored in association with the known or existing specified state variables, for example in a controller of the LED lighting device, so that the LED lighting device can be controlled accordingly in the future.
Wie
Wie
Wie
Gemäß den Ausführungsformen der
Die dargestellte Kalibrierungsvorrichtung 11 weist weiter eine, mit einer in
Gemäß den Ausführungsformen der
Weiter kann es sich bei der ersten Recheneinheit 18 insbesondere um eine Recheneinheit, auf welcher Code zum Ermitteln von Emissionsspektren der einzelnen LEDs 13,14,15 aus dem gemessenen Spektrum des erzeugten Lichts zu ermitteln, gespeichert und ausführbar ist, handeln. Entsprechend kann es sich bei der zweiten Recheneinheit 19 um eine Recheneinheit, auf welcher Code zum Berechnen von Tristimuluswerten basierend auf den einzelnen Emissionsspektren der einzelnen LEDs 13,14,15 gespeichert und ausführbar ist, handeln.Furthermore, the
Gemäß den Ausführungsformen der
Zu erkennen ist weiter auch eine dritte Recheneinheit 22, welche ausgebildet ist für jedes der Emissonsspektren der einzelnen LEDs 13,14,15 jeweils eine Regressionsanalyse durchzuführen, um abgeschnittene Spektrumsbereiche zu ergänzen, auf. Gemäß den Ausführungsformen der
Zu erkennen ist zudem eine Kontrolleinrichtung 23, welche ausgebildet ist, Kontrollmessungen durchzuführen, um die berechneten Tristimuluswerte zu verifizieren.A
Gemäß den Ausführungsformen der
Dabei kann es sich bei dem Vergleicher 25 wiederum um eine Recheneinheit, auf welcher Code zum Vergleichen von den Zustandsgrößen zugeordneten abgespeicherten Tristimuluswerte mit nach dem Ansteuern mit den Zustandsgrößen tatsächlich vorliegenden, über ein Spektrometer gemessenen Farbwerten gespeichert und ausführbar ist, handeln. Bei der Aktualisierungseinheit 26 kann es sich wiederum um eine Recheneinheit, auf welcher Code zum Berechnen eines neuen Tristimulswert, um einen gespeicherten Tristimuluswert zu aktualisieren, falls dieser von einem entsprechenden tatsächlich vorliegenden Farbwert abweicht, gespeichert und ausführbar ist, handeln.The
Die Aktualisierungseinheit 26 ist dabei insbesondere derart ausgebildet, den gespeicherten Tristimuluswert mit dem neu berechneten Tristimuluswert zu überschreiben, das heißt den neu berechneten Tristimuluswert nunmehr entsprechend in Zuordnung zu den vorliegenden beziehungsweise vorgegebenen Zustandsgrößen zu speichern.The
Die zweite Ansteuereinheit 24 ist dabei gemäß den Ausführungsformen der
- 11
- Verfahrenprocedure
- 22
- Verfahrensschrittprocess step
- 33
- Verfahrensschrittprocess step
- 44
- Verfahrensschrittprocess step
- 55
- Verfahrensschrittprocess step
- 66
- Verfahrensschrittprocess step
- 77
- Verfahrensschrittprocess step
- 88th
- Verfahrensschrittprocess step
- 99
- Verfahrensschrittprocess step
- 1010
- Systemsystem
- 1111
- Kalibrierungsvorrichtungcalibration device
- 1212
- LED-BeleuchtungseinrichtungLED lighting device
- 1313
- rote LEDred LED
- 1414
- grüne LEDgreen LED
- 1515
- blaue LEDblue LED
- 1616
- erste Ansteuereinheitfirst control unit
- 1717
- Spektrometerspectrometer
- 1818
- erste Recheneinheitfirst unit of account
- 1919
- zweite Recheneinheitsecond computing unit
- 2020
- SpeicherStorage
- 2121
- Bandpassfilterbandpass filter
- 2222
- dritte Recheneinheitthird unit of account
- 2323
- Kontrolleinrichtungcontrol device
- 2424
- zweite Ansteuereinheitsecond control unit
- 2525
- Vergleichercomparator
- 2626
- Aktualisierungseinheitupdate unit
Claims (11)
dadurch gekennzeichnet, dass die erste Recheneinheit (18) ein Bandpassfilter (21) aufweist und die erste Recheneinheit (18) ausgebildet ist, die Emissionsspektren der einzelnen LEDs (13,14,15) beziehungsweise LED-Farbgruppen durch Ermitteln lokaler Minima in dem gemessenen Spektrum des erzeugten Lichtes zu ermitteln.Calibration device for calibrating color or photometric properties of an LED lighting device (12) with LEDs (13, 14, 15) emitting light of different colors or wavelengths, or LED color groups, which emit light of the same color or wavelength within a color group, the luminous flux components of which Determine light colour, color temperature and/or the color locus of the light mixture emitted by the LED lighting device (12), with the calibration device (11) having a first control unit (16) which is designed for all LEDs (13, 14, 15) or LED color groups to drive in parallel to generate light, a spectrometer (17) to measure a spectrum of the by driving in parallel all the LEDs (13,14,15) or LED color groups generated light, a first processing unit (18) which is designed to determine emission spectra of the individual LEDs (13, 14, 15) or LED color groups from the measured spectrum of the generated light, a second processing unit (19) which is designed to calculate tristimulus values based on the individual emission spectra of the individual LEDs (13,14,15) or LED case groups, and having a memory (20) for storing the calculated tristimulus values in association with the known state variables,
characterized in that the first arithmetic unit (18) has a bandpass filter (21) and the first arithmetic unit (18) is designed to determine the emission spectra of the individual LEDs (13,14,15) or LED color groups by determining local minima in the measured spectrum of the generated light.
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DE102007044556A1 (en) | 2007-09-07 | 2009-03-12 | Arnold & Richter Cine Technik Gmbh & Co. Betriebs Kg | Method and device for adjusting the color or photometric properties of an LED lighting device |
DE102010044736A1 (en) | 2009-09-10 | 2011-04-21 | Just Normlicht Gmbh Vertrieb + Produktion | Method and device for simulating daylight spectra of high quality |
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2021
- 2021-03-18 DE DE102021202642.7A patent/DE102021202642A1/en not_active Withdrawn
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2022
- 2022-03-15 EP EP22162158.4A patent/EP4061098A1/en not_active Withdrawn
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US20040105261A1 (en) | 1997-12-17 | 2004-06-03 | Color Kinetics, Incorporated | Methods and apparatus for generating and modulating illumination conditions |
DE202005001540U1 (en) | 2005-02-01 | 2005-05-19 | Grantz, Helmut, Dipl.-Ing. | Adjustable color daylight source has at least one light emitting diode emitting white light of defined color temperature combined with light emitting diodes emitting light of least two different colors |
US20070216704A1 (en) * | 2005-11-18 | 2007-09-20 | Cree, Inc. | Systems and methods for calibrating solid state lighting panels using combined light output measurements |
DE102007036978A1 (en) | 2007-08-06 | 2009-02-12 | Tridonicatco Gmbh & Co. Kg | Device and method for controlling the light output |
DE102007044556A1 (en) | 2007-09-07 | 2009-03-12 | Arnold & Richter Cine Technik Gmbh & Co. Betriebs Kg | Method and device for adjusting the color or photometric properties of an LED lighting device |
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