EP2062461B1 - Control method, control device, and method for the production of the control device - Google Patents
Control method, control device, and method for the production of the control device Download PDFInfo
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- EP2062461B1 EP2062461B1 EP08706896.1A EP08706896A EP2062461B1 EP 2062461 B1 EP2062461 B1 EP 2062461B1 EP 08706896 A EP08706896 A EP 08706896A EP 2062461 B1 EP2062461 B1 EP 2062461B1
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- 238000000034 method Methods 0.000 title claims description 25
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- 230000005855 radiation Effects 0.000 claims description 93
- 239000004065 semiconductor Substances 0.000 claims description 77
- 230000004907 flux Effects 0.000 claims description 69
- 230000002123 temporal effect Effects 0.000 claims description 9
- 238000010586 diagram Methods 0.000 description 13
- 230000006870 function Effects 0.000 description 11
- 230000000630 rising effect Effects 0.000 description 7
- 238000010438 heat treatment Methods 0.000 description 6
- 230000008901 benefit Effects 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 239000000463 material Substances 0.000 description 4
- 238000005259 measurement Methods 0.000 description 3
- 239000003086 colorant Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 230000001174 ascending effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000011664 signaling Effects 0.000 description 1
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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]
- H05B45/30—Driver circuits
- H05B45/37—Converter circuits
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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]
- H05B45/10—Controlling the intensity of the light
- H05B45/14—Controlling the intensity of the light using electrical feedback from LEDs or from LED modules
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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
Definitions
- the invention relates to a control method and a control device for operating at least one radiation-emitting semiconductor component.
- the invention further relates to a method for producing the control device.
- Radiation-emitting semiconductor components are used, for example, as light-emitting diodes, or in short: LEDs, for signaling purposes and increasingly also for illumination purposes.
- LEDs of different colors in particular red, green or blue LEDs, are used for projecting color images.
- the LEDs of different color alternately illuminate, in rapid succession, an array of micromirrors which are controlled in such a way that the desired color impression of a respective pixel results as a function of the respective time duration that the light of the respective LED falls on the respective pixel.
- a viewer creates a colored picture impression, which can also include mixed colors, for example white.
- the LEDs must be operated in each case in a pulse mode, that is, in rapid succession on and off again.
- the object of the invention is to provide a control method, a control device and a method for producing the control device, the one or more Pulse operation of a radiation-emitting semiconductor device with a homogeneous radiation flux allows.
- Similar LED control circuits are known from the patent documents US 6242870B1 and US 6356774B1 ,
- the invention is characterized by a control method and a corresponding control device.
- a pulse-shaped, during a pulse duration increasing, electrical operating current is generated.
- the pulse duration does not include an ascending or falling edge of the electrical operating current, which is produced by switching the electrical operating current on or off.
- the invention is based on the finding that the at least one radiation-emitting semiconductor component heats up during the pulse duration and as a result the radiation flux decreases during the pulse duration if the electrical operating current remains substantially constant during the pulse duration. By the increasing during the pulse duration operating current can be counteracted the drop in the radiation flux. As a result, reliable pulse operation of the at least one radiation-emitting semiconductor component is possible.
- the electrical operating current is generated such that a radiation flux of the at least one radiation-emitting Semiconductor device during the pulse duration changed only within a predetermined Radfl Wegtoleranzbandes.
- the electrical operating current is generated such that the radiation flux of the at least one radiation-emitting semiconductor component is substantially constant.
- a pulse-shaped, electrical switching current is generated.
- An electrical compensation current is generated, which is superimposed on the electrical switching current for generating the electrical operating current of the at least one radiation-emitting semiconductor component.
- the electrical compensation current increases during the pulse duration. In this way, the electrical operating current rising during the pulse duration is very easily generated.
- the advantage is that the electrical switching current and the electrical compensation current can be generated independently of each other.
- the electrical switching current is for example very simple rectangular generated. This is superimposed with the rising electrical compensation current.
- a profile of the electrical operating current or of the electrical compensation current is generated as a function of a sum over at least one summand of the form A * (1-exp (-t / tau)).
- a time constant tau and a factor A are given in each case.
- this is formed together with the at least one radiation-emitting semiconductor component as a common structural unit.
- the control device forms a driver circuit for the at least one radiation-emitting semiconductor component.
- the control device can be designed to be adjusted in accordance with the associated at least one radiation-emitting semiconductor component, so that the associated at least one radiation-emitting semiconductor component can be controlled particularly precisely and the resulting radiation flux is particularly reliable.
- the invention is characterized by a method for producing the control device for operating at least one radiation-emitting semiconductor component by means of a pulse-shaped electrical operating current rising during a pulse duration.
- a temporal profile of a thermal impedance is determined, which is representative of the at least one radiation-emitting semiconductor component.
- a course to be set of the electrical operating current is determined.
- the control device is further configured that the course of the operating current to be set is set in each case during the pulse duration.
- the pulse duration does not include a rising or falling edge of the electrical operating current, which is produced by switching on or off the electrical operating current.
- the temporal course of the thermal impedance of the at least one radiation-emitting semiconductor component is in particular easily detectable by measurement and is essentially dependent on the type of construction and the material.
- the temporal course of the thermal impedance is not determined for each individual radiation-emitting semiconductor component, but is determined representatively for all or a subset of the radiation-emitting semiconductor components of the same type and the same material selection.
- the control device is simple and inexpensive to produce in large quantities.
- the course of the electrical operating current to be set is determined such that a radiation flux of the at least one radiation-emitting semiconductor component changes during the pulse duration only within a predetermined radiation flux tolerance band.
- the course of the electrical operating current to be set is determined such that the radiation flux of the at least one radiation-emitting semiconductor component is substantially constant.
- a voltage-current characteristic and / or a radiation flux-current characteristic and / or a radiation flux-junction temperature characteristic is determined, which is in each case representative of the at least one radiation-emitting semiconductor component.
- the voltage-current characteristic and / or radiation flux-current characteristic and / or radiation flux junction temperature characteristic curve is the course to be set of the electrical operating current or the electric Compensating current determined.
- the characteristic curves are generally known from, for example, manufacturer-provided characteristics of the at least one radiation-emitting semiconductor component or can be determined simply by measurement. By taking into account at least one of the characteristic curves, the course to be set of the electrical operating current or of the electrical compensation current can be determined precisely.
- the course to be set of the electrical operating current or of the electrical compensation current is determined as a function of a sum over at least one summand of the form A * (1-exp (-t / tau)).
- a time constant tau is determined in each case depending on the time characteristic of the thermal impedance.
- a factor A is determined in each case depending on the determined voltage-current characteristic and / or the determined radiation flux-current characteristic and / or the determined radiation flux-junction temperature characteristic.
- the respective time constant tau and / or the respective factor A can be determined, for example, by approximation to a predetermined course of the electrical operating current or of the electric compensation current, which is predetermined by a physical model of the at least one radiation-emitting semiconductor component.
- the temporal profile of the thermal impedance and / or the determined voltage-current characteristic and / or the determined radiation flux-current characteristic and / or the determined radiation flux-junction temperature characteristic curve are preferably supplied to the physical model. In this way, the course to be set of the electrical operating current or the electrical Compensating current easily determined with the desired precision.
- the pulse duration PD includes a duration for each pulse between a switch-on phase and a switch-off phase.
- the radiant flux ⁇ e changes due to a switch-on process or a switch-off process.
- the radiation flux ⁇ e should be substantially constant.
- FIG. 1 1 left, shows a radiation flux-junction temperature characteristic in which a first radiation flux ratio is plotted against a junction temperature T j of a radiation-emitting semiconductor component 1.
- the first radiation flux ratio is formed by a ratio of a radiation flux ⁇ e of the radiation-emitting semiconductor component 1 with respect to the radiation flux ⁇ e, which results at a predetermined junction temperature of 25 ° C.
- the first radiation flux ratio can also be formed differently.
- junction temperature Tj which may also be referred to as junction temperature
- the radiation flux ⁇ e decreases.
- the radiation flux ⁇ e during the respective pulse duration PD then generally decreases with increasing heating.
- FIG. 1 bottom left shows a radiation flux-current characteristic of the radiation-emitting semiconductor device 1, in which a second radiation flux ratio against an electrical operating current If of the radiation-emitting Semiconductor device is applied.
- the second radiation flux ratio is formed by a ratio of the radiation flux ⁇ e of the radiation-emitting semiconductor component 1 with respect to the radiation flux ⁇ e, which results at a predetermined operating current of 750 mA.
- the second radiation flux ratio can also be specified differently. With increasing operating current If the radiation flux ⁇ e increases.
- the radiation flux ⁇ e can not be arbitrarily increased by increasing the operating current If, and decreases even if the operating current If and the pulse width PD are too long or the duty cycle is too long.
- a radiation flux-current-time diagram can be determined, the right in the FIG. 1 is shown.
- a third radiation flux ratio is plotted against the operating current If and a time t.
- the third radiation flux ratio is formed by a ratio of the radiation flux ⁇ e of the radiation-emitting Semiconductor device 1 with respect to a predetermined reference radiation flux ⁇ e0.
- the predetermined reference radiation flux ⁇ e0 is predetermined, for example, as the radiation flux ⁇ e, which results at the predetermined junction temperature of 25 ° C and at the predetermined operating current of 750 mA.
- the predetermined reference radiation flux ⁇ e0 can also be specified differently.
- the third radiation flux ratio can also be formed differently.
- the radiation flux-current-time diagram can be determined, for example, by a physical model of the radiation-emitting semiconductor component 1, which is in particular an electro-thermo-optical model in which the relevant electrical, thermal and optical variables are suitably linked to one another.
- the electrical quantities include, for example, the operating current If, which flows through the radiation-emitting semiconductor component 1, and a voltage which drops across the radiation-emitting semiconductor component 1.
- the thermal parameters include, for example, a thermal power as well as thermal resistances and thermal capacitances, which are predetermined by the materials and their arrangement in the radiation-emitting semiconductor component 1.
- the optical quantities include, for example, the radiation flux ⁇ e. Also, other or other quantities may be considered in the physical model.
- the physical model is preferably given the radiation flux-junction temperature characteristic, the radiant-flux-current characteristic, the profile of the thermal impedance Zth and optionally a voltage-current characteristic.
- the voltage-current characteristic is the voltage that is above the radiation-emitting Semiconductor device drops, applied over the operating current If.
- the characteristics and the time profile of the thermal impedance Zth can be determined, for example, by measuring.
- the time profile of the thermal impedance Zth can be determined, for example, by a heating or cooling process and is dependent on the thermal resistances and the thermal capacitances of the radiation-emitting semiconductor component 1.
- the characteristics and the course of the thermal impedance Zth are characteristic of the respective radiation-emitting semiconductor component 1.
- FIG. 3 shows a section of the radiation flow-current-time diagram according to FIG. 1 in the event that the third radiation flux ratio is to be kept constant at a value of 1.
- the operating current If to be set for the constant third radiation flux ratio results as a contour line in the radiation flux-current-time diagram or, in other words, as a section line in the plane of the third radiation flux ratio with the constant value 1. Accordingly, the operating current If also to be set be determined for a different value of the third radiation flux ratio.
- the Radiation Flow-Current-Time Diagram in FIG. 3 It can be seen that the third radiation flux ratio can not be kept at the value of 1 for any length of time. A further increase in the operating current If causes no increase due to the associated heating of the radiation-emitting semiconductor component 1, but a reduction in the radiation flux ⁇ e.
- the pulse duration PD must therefore be so short or the duty cycle be so small that the third radiation flux ratio and thus the radiation flux ⁇ e can be kept substantially constant by increasing the operating current If. It can also be provided to keep the third radiation flux ratio constant at a value other than 1, in particular at a lower value.
- the result for the course of the operating current If to be set is a different cutting line or contour line.
- the pulse duration PD may be longer or the duty cycle may be greater without the radiation flux ⁇ e decreasing during the pulse duration PD.
- the profile of the operating current If to be set is determined, set and generated as an overlay, that is to say as a sum, of an electrical switching current Is and of an electric compensation current Ik, in order to compensate for the drop in the radiation flux .phi.e due to the heating during the respective pulse duration PD.
- the electrical switching current Is is preferably provided rectangular and therefore corresponds to rectangular pulses.
- the electrical switching current Is is preferably substantially constant during the pulse duration PD and serves for switching on the radiation-emitting semiconductor component 1 during the pulse duration PD and for otherwise switching off the radiation-emitting semiconductor component 1.
- the compensation electric current Ik is provided so that it increases during the pulse duration PD, to compensate for the drop of the radiation flux ⁇ e due to the heating of the radiation-emitting semiconductor device 1. According to the electrical Compensation current Ik also increases the electrical operating current If during the pulse duration PD.
- FIG. 4 shows a first current-time diagram in which the compensation current Ik, as it can be determined, for example, by means of the physical model, is plotted over the time t.
- a profile of an approximated compensation current Ia is determined as an approximation of the profile of the compensation current Ik, which represents the course of the compensation current Ik to be set.
- the profile of the approximated compensation current Ia is determined as a function of a sum over at least one summand of the form A * (1-exp (-t / tau)).
- FIG. 4 shows the course of the approximated compensation current Ia for a single summand. By considering further summands, the precision of the approximation can be improved. In the example of FIG.
- a time constant tau is determined in each case depending on the time characteristic of the thermal impedance Zth. If the number of summands equal to a number of thermal resistance capacitance elements or thermal RC elements of the radiation-emitting semiconductor component 1 is chosen, which characterize the course of the thermal impedance Zth, then the respective time constant tau corresponds to a respective time constant which is defined by one of the thermal RCs. limbs of the radiation-emitting semiconductor component 1 are predetermined. The thermal resistances and the thermal capacitances that form the thermal RC elements, and thus also the associated time constants, can be determined as a function of the course of the thermal impedance Zth.
- a factor A is determined in each case depending on the voltage-current characteristic and / or the radiant-flux-current characteristic and / or the radiant-flux junction temperature characteristic. Due to the simplicity of the function of the individual summands, the profile of the approximated compensation current Ia can be generated very easily, for example by means of suitably designed electrical resistance-capacitance elements, which can also be referred to as electrical RC elements.
- FIG. 5 shows a second current-time diagram with a measured course of the radiation flux ⁇ e, which is kept substantially constant by the increasing operating current If. Furthermore, the measured course of the operating current If is shown.
- the radiation flux ⁇ e should remain substantially constant during the pulse duration PD.
- the radiation flux ⁇ e during the pulse duration PD should be within a predetermined radiation flux tolerance band ⁇ etol, by which a maximum fluctuation range of the radiation flux ⁇ e is predetermined.
- the width of the predetermined radiation flux tolerance band ⁇ etol can be specified according to the requirements.
- the operating current If and, if necessary, the compensation current Ik or the approximated one must be correspondingly precise Compensation current Ia are generated.
- the predetermined radiation flux tolerance band ⁇ etol can also be specified differently.
- FIG. 6 shows a control device 2 and a radiation-emitting semiconductor device 1, which is electrically coupled to an output of the control device 2.
- the control device is electrically coupled to an operating potential VB and a reference potential GND.
- the control device 3 can be coupled to a control line, via the control device 2, for example, control signals can be supplied to trigger the respective pulse for the pulse operation of the radiation-emitting semiconductor device 1.
- the control device 2 is formed, the pulse-shaped, during the pulse duration PD rising, electrical operating current If to generate for driving the radiation-emitting semiconductor device 1.
- the control device 2 is designed as a driver circuit for the radiation-emitting semiconductor component 1.
- control device 2 and the radiation-emitting semiconductor component 1 are preferably formed together as a common structural unit in a module 4. It can also be provided to operate two or more radiation-emitting semiconductor components 1 by the control device 2 and / or to arrange them in the module 4.
- FIG. 7 shows a first flowchart of a method for manufacturing the control device 2.
- the method begins in a step S1.
- the time profile of the thermal impedance Zth is determined. This is preferably representative of a group of similar radiation-emitting semiconductor components 1 Similarity relates in particular to the design and the selection of materials.
- the temporal courses of the thermal impedance Zth differ between different radiation-emitting semiconductor components 1 within the group only to a tolerable extent from each other. Thus, it may not be necessary to determine for each individual radiation-emitting semiconductor component 1 the time profile of the thermal impedance Zth.
- the radiation-flux-junction temperature characteristic and / or the radiant-flux-current characteristic and / or the voltage-current characteristic are also determined in step S2, preferably representative of the group of radiation-emitting semiconductor components 1.
- a step S3 may be provided, in which the control device 2 is formed so that the pulse-shaped, preferably rectangular electrical switching current Is can be generated.
- a step S4 may be provided in which the course of the electrical compensation current Ik rising during the pulse duration PD is determined, optionally in the form of the approximated compensation current Ia. The determination takes place as a function of the detected course of the thermal impedance Zth. The determination preferably takes place by means of the physical model of the radiation-emitting semiconductor component 1, to which the detected profile of the thermal impedance Zth is predetermined. For this purpose, for example, the course of the desired contour line in the radiation flux-current-time diagram is determined and, if appropriate, the approximation of the approximated compensation current Ia is carried out. The approximation, for example, determines parameters that can be used to set the compensation current Ik. The Determining the course to be set of the compensation current Ik, however, can also be done differently.
- a step S5 may be provided in which the operating current If to be set is determined as a superposition or sum of the switching current Is and the compensation current Ik.
- the control device 2 is designed such that the operating current If to be set can be generated during operation. This can be done for example by forming an electrical circuit arrangement and suitable dimensioning of electrical RC elements.
- a further possibility is, for example, to provide a function generator which is designed to provide on the output side a signal curve corresponding to the course of the operating current If to be set or of the compensation current Ik to be set.
- the control device 2 may be formed differently in the step S6.
- the method ends in a step S7. It can also be provided to determine the operating current If to be set depending on the determined characteristic of the thermal impedance Zth in a step S8, without the switching current Is and the compensation current Ik being determined for this purpose have to.
- the step S8 may therefore optionally replace the steps S3 to S5.
- FIG. 8 shows a second flowchart of a control method for operating the at least one radiation-emitting semiconductor element 1 by means of the pulse-shaped, during the pulse duration PD increasing, electrical operating current If.
- the control method is preferably carried out by the control device 2.
- the control method can be implemented, for example, in the form of the electrical circuit arrangement in the control device 2.
- the electrical circuit arrangement comprises, for example, the electrical RC elements.
- the control method may also be implemented as a program and stored in a memory included by the control device 2 or electrically coupled to the control device 2.
- the control device 2 then comprises, for example, a computing unit which executes the program.
- the arithmetic unit controls the digital-to-analog converter or another component of the control unit which is designed to set the course of the compensation current Ik or of the operating current If to be set.
- the control process starts in a step S10.
- a step S11 the pulse-shaped, preferably rectangular, electrical switching current Is is generated.
- the compensating current Ik to be set is set, for example in the form of the approximated compensating current Ia, and generated accordingly.
- the operating current If is superimposed or sum of the switching current Is and the compensation current Ik generated and output in a step S14 to the at least one radiation-emitting semiconductor device 1.
- the control process ends in a step S15. It may also be provided to generate the increasing operating current If in a step S16, without the switching current Is and the compensation current Ik having to be generated for this purpose.
- the step S16 may therefore optionally replace the steps S11 to S13.
- control device 3 control line 4 module ⁇ e radiant flux ⁇ e0 predetermined reference radiation flux ⁇ etol given radiation flux tolerance band GND reference potential Ia approximated compensation current If operating current Ik compensating current is switching current PD pulse duration S1-16 step t Time tj Junction temperature VB operating potential Z th thermal impedance
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Description
Die Erfindung betrifft ein Steuerverfahren und eine Steuervorrichtung zum Betreiben mindestens eines strahlungsemittierenden Halbleiterbauelements. Die Erfindung betrifft ferner ein Verfahren zum Herstellen der Steuervorrichtung.The invention relates to a control method and a control device for operating at least one radiation-emitting semiconductor component. The invention further relates to a method for producing the control device.
Strahlungsemittierende Halbleiterbauelemente werden beispielsweise als lichtemittierende Dioden, oder kurz: LED, für Signalisierungszwecke und in zunehmendem Maße auch für Beleuchtungszwecke genutzt. Beispielsweise werden LEDs unterschiedlicher Farbe, insbesondere rot, grün oder blau leuchtende LEDs, genutzt für das Projizieren von Farbbildern. Die LEDs unterschiedlicher Farbe beleuchten dazu abwechselnd in schneller Folge eine Anordnung von Mikrospiegeln, die so angesteuert werden, dass sich der gewünschte Farbeindruck eines jeweiligen Bildpunkts abhängig von der jeweiligen Zeitdauer ergibt, die das Licht der jeweiligen LED auf den jeweiligen Bildpunkt fällt. Durch das abwechselnde Projizieren in schneller Folge beispielsweise eines roten, eines grünen und eines blauen Teilbildes entsteht bei einem Betrachter ein farbiger Bildeindruck, der auch Mischfarben umfassen kann, zum Beispiel weiß. Die LEDs müssen dazu jeweils in einem Impulsbetrieb betrieben werden, das heißt in schneller Folge ein- und wieder ausgeschaltet werden.Radiation-emitting semiconductor components are used, for example, as light-emitting diodes, or in short: LEDs, for signaling purposes and increasingly also for illumination purposes. For example, LEDs of different colors, in particular red, green or blue LEDs, are used for projecting color images. For this purpose, the LEDs of different color alternately illuminate, in rapid succession, an array of micromirrors which are controlled in such a way that the desired color impression of a respective pixel results as a function of the respective time duration that the light of the respective LED falls on the respective pixel. By alternately projecting in rapid succession, for example, a red, a green and a blue part of a picture, a viewer creates a colored picture impression, which can also include mixed colors, for example white. The LEDs must be operated in each case in a pulse mode, that is, in rapid succession on and off again.
Die Aufgabe der Erfindung ist, ein Steuerverfahren, eine Steuervorrichtung und ein Verfahren zum Herstellen der Steuervorrichtung zu schaffen, das beziehungsweise die einen Impulsbetrieb eines strahlungsemittierenden Halbleiterbauelements mit einem homogenen Strahlungsfluss ermöglicht. Ähnliche LED-Steuerschaltungen sind bekannt aus den Patentschrifte
Die Aufgabe wird gelöst durch die Merkmale der unabhängigen Patentansprüche. Vorteilhafte Weiterbildungen der Erfindung sind in den Unteransprüchen gekennzeichnet.The object is solved by the features of the independent claims. Advantageous developments of the invention are characterized in the subclaims.
Gemäß eines ersten Aspekts zeichnet sich die Erfindung aus durch ein Steuerverfahren und eine entsprechende Steuervorrichtung. Zum Betreiben mindestens eines strahlungsemittierenden Halbleiterbauelements wird ein impulsförmiger, während einer Impulsdauer ansteigender, elektrischer Betriebsstrom erzeugt. Die Impulsdauer umfasst dabei insbesondere nicht eine ansteigende oder abfallende Flanke des elektrischen Betriebsstroms, die durch ein Einschalten oder Ausschalten des elektrischen Betriebsstroms entsteht.According to a first aspect, the invention is characterized by a control method and a corresponding control device. For operating at least one radiation-emitting semiconductor component, a pulse-shaped, during a pulse duration increasing, electrical operating current is generated. In particular, the pulse duration does not include an ascending or falling edge of the electrical operating current, which is produced by switching the electrical operating current on or off.
Die Erfindung beruht auf der Erkenntnis, dass sich das mindestens eine strahlungsemittierende Halbleiterbauelement während der Impulsdauer erwärmt und dadurch der Strahlungsfluss während der Impulsdauer abnimmt, wenn der elektrische Betriebsstrom während der Impulsdauer im Wesentlichen konstant bleibt. Durch den während der Impulsdauer ansteigenden Betriebsstrom kann dem Abfallen des Strahlungsflusses entgegengewirkt werden. Dadurch ist ein zuverlässiger Impulsbetrieb des mindestens einen strahlungsemittierenden Halbleiterbauelements möglich.The invention is based on the finding that the at least one radiation-emitting semiconductor component heats up during the pulse duration and as a result the radiation flux decreases during the pulse duration if the electrical operating current remains substantially constant during the pulse duration. By the increasing during the pulse duration operating current can be counteracted the drop in the radiation flux. As a result, reliable pulse operation of the at least one radiation-emitting semiconductor component is possible.
In einer vorteilhaften Ausgestaltung wird der elektrische Betriebsstrom derart erzeugt, dass sich ein Strahlungsfluss des mindestens einen strahlungsemittierenden Halbleiterbauelements während der Impulsdauer nur innerhalb eines vorgegebenen Strahlungsflusstoleranzbandes verändert. Insbesondere wird der elektrische Betriebsstrom derart erzeugt, dass der Strahlungsfluss des mindestens einen strahlungsemittierenden Halbleiterbauelements im Wesentlichen konstant ist. Dies hat den Vorteil, dass das mindestens eine strahlungsemittierende Halbleiterbauelement dadurch besonders gut für Anwendungen geeignet ist, bei denen das mindestens eine strahlungsemittierende Halbleiterbauelement im Impulsbetrieb betrieben wird und bei denen eine hohe Gleichmäßigkeit und Schwankungsarmut des Strahlungsflusses während der Impulsdauer gefordert wird.In an advantageous embodiment, the electrical operating current is generated such that a radiation flux of the at least one radiation-emitting Semiconductor device during the pulse duration changed only within a predetermined Radflflusstoleranzbandes. In particular, the electrical operating current is generated such that the radiation flux of the at least one radiation-emitting semiconductor component is substantially constant. This has the advantage that the at least one radiation-emitting semiconductor component is thereby particularly well suited for applications in which the at least one radiation-emitting semiconductor component is operated in pulse mode and in which a high uniformity and fluctuation of the radiation flux during the pulse duration is required.
In einer weiteren vorteilhaften Ausgestaltung wird ein impulsförmiger, elektrischer Schaltstrom erzeugt. Ein elektrischer Kompensationsstrom wird erzeugt, der dem elektrischen Schaltstrom überlagert wird zum Erzeugen des elektrischen Betriebsstroms des mindestens einen strahlungsemittierenden Halbleiterbauelements. Der elektrische Kompensationsstrom steigt während der Impulsdauer an. Auf diese Weise wird der während der Impulsdauer ansteigende elektrische Betriebsstrom sehr einfach erzeugt. Der Vorteil ist, dass der elektrische Schaltstrom und der elektrische Kompensationsstrom unabhängig voneinander erzeugbar sind. Der elektrische Schaltstrom ist beispielsweise sehr einfach rechteckförmig erzeugbar. Dieser wird mit dem ansteigenden elektrischen Kompensationsstrom überlagert.In a further advantageous embodiment, a pulse-shaped, electrical switching current is generated. An electrical compensation current is generated, which is superimposed on the electrical switching current for generating the electrical operating current of the at least one radiation-emitting semiconductor component. The electrical compensation current increases during the pulse duration. In this way, the electrical operating current rising during the pulse duration is very easily generated. The advantage is that the electrical switching current and the electrical compensation current can be generated independently of each other. The electrical switching current is for example very simple rectangular generated. This is superimposed with the rising electrical compensation current.
In einer weiteren vorteilhaften Ausgestaltung wird ein Verlauf des elektrischen Betriebsstroms beziehungsweise des elektrischen Kompensationsstroms erzeugt abhängig von einer Summe über mindestens einen Summanden der Form A * (1 - exp(-t/tau)). Eine Zeitkonstante tau und ein Faktor A sind jeweils vorgegeben. Dies hat den Vorteil, dass die Präzision des Verlaufs des elektrischen Betriebsstroms beziehungsweise des elektrischen Kompensationsstroms sehr einfach über eine Anzahl der Summanden vorgebbar ist. Ferner ist der Verlauf auf diese Weise einfach und kostengünstig erzeugbar.In a further advantageous embodiment, a profile of the electrical operating current or of the electrical compensation current is generated as a function of a sum over at least one summand of the form A * (1-exp (-t / tau)). A time constant tau and a factor A are given in each case. This has the advantage that the precision of the course of the electrical operating current or the electric compensation current can be specified very easily over a number of summands. Furthermore, the course can be generated in this way easily and inexpensively.
In einer weiteren vorteilhaften Ausgestaltung der Steuervorrichtung ist diese zusammen mit dem mindestens einen strahlungsemittierenden Halbleiterbauelement als eine gemeinsame Baueinheit ausgebildet. Insbesondere bildet die Steuervorrichtung eine Treiberschaltung für das mindestens eine strahlungsemittierende Halbleiterbauelement. Durch das Ausbilden als eine gemeinsame Baueinheit, beispielsweise als ein Modul, kann diese besonders kompakt ausgebildet sein. Ferner kann die Steuervorrichtung entsprechend dem zugehörigen mindestens einen strahlungsemittierenden Halbleiterbauelement justiert ausgebildet sein, so dass das zugehörige mindestens eine strahlungsemittierende Halbleiterbauelement besonders präzise ansteuerbar ist und der resultierende Strahlungsfluss besonders zuverlässig ist.In a further advantageous embodiment of the control device, this is formed together with the at least one radiation-emitting semiconductor component as a common structural unit. In particular, the control device forms a driver circuit for the at least one radiation-emitting semiconductor component. By forming as a common structural unit, for example as a module, it can be made particularly compact. Furthermore, the control device can be designed to be adjusted in accordance with the associated at least one radiation-emitting semiconductor component, so that the associated at least one radiation-emitting semiconductor component can be controlled particularly precisely and the resulting radiation flux is particularly reliable.
Gemäß eines zweiten Aspekts zeichnet sich die Erfindung aus durch ein Verfahren zum Herstellen der Steuervorrichtung zum Betreiben mindestens eines strahlungsemittierenden Halbleiterbauelements mittels eines impulsförmigen, während einer Impulsdauer ansteigenden, elektrischen Betriebsstroms. Ein zeitlicher Verlauf einer thermischen Impedanz wird ermittelt, die repräsentativ ist für das mindestens eine strahlungsemittierende Halbleiterbauelement. Abhängig von dem ermittelten zeitlichen Verlauf der thermischen Impedanz wird ein einzustellender Verlauf des elektrischen Betriebsstroms ermittelt. Die Steuervorrichtung wird ferner so ausgebildet, dass der einzustellende Verlauf des Betriebsstroms jeweils während der Impulsdauer eingestellt wird. Die Impulsdauer umfasst insbesondere nicht eine ansteigende oder abfallende Flanke des elektrischen Betriebsstroms, die durch ein Einschalten oder Ausschalten des elektrischen Betriebsstroms entsteht.According to a second aspect, the invention is characterized by a method for producing the control device for operating at least one radiation-emitting semiconductor component by means of a pulse-shaped electrical operating current rising during a pulse duration. A temporal profile of a thermal impedance is determined, which is representative of the at least one radiation-emitting semiconductor component. Depending on the determined temporal course of the thermal impedance, a course to be set of the electrical operating current is determined. The control device is further configured that the course of the operating current to be set is set in each case during the pulse duration. In particular, the pulse duration does not include a rising or falling edge of the electrical operating current, which is produced by switching on or off the electrical operating current.
Der zeitliche Verlauf der thermischen Impedanz des mindestens einen strahlungsemittierenden Halbleiterbauelements ist insbesondere einfach messtechnisch ermittelbar und ist im Wesentlichen bauart- und materialabhängig. Vorteilhafterweise wird der zeitliche Verlauf der thermischen Impedanz nicht für jedes einzelne strahlungsemittierende Halbleiterbauelement ermittelt, sondern wird repräsentativ für alle oder eine Untermenge der strahlungsemittierenden Halbleiterbauelemente gleicher Bauart und gleicher Materialauswahl ermittelt. Dadurch ist die Steuervorrichtung einfach und kostengünstig in großen Stückzahlen herstellbar. Durch Nutzen des Verlaufs der thermischen Impedanz ist der einzustellende Verlauf des elektrischen Betriebsstroms beziehungsweise des elektrischen Kompensationsstroms präzise ermittelbar.The temporal course of the thermal impedance of the at least one radiation-emitting semiconductor component is in particular easily detectable by measurement and is essentially dependent on the type of construction and the material. Advantageously, the temporal course of the thermal impedance is not determined for each individual radiation-emitting semiconductor component, but is determined representatively for all or a subset of the radiation-emitting semiconductor components of the same type and the same material selection. As a result, the control device is simple and inexpensive to produce in large quantities. By utilizing the course of the thermal impedance of the course to be set of the electrical operating current or the electric compensation current is precisely determined.
In einer vorteilhaften Ausgestaltung des zweiten Aspekts wird der einzustellende Verlauf des elektrischen Betriebsstroms derart ermittelt, dass sich ein Strahlungsfluss des mindestens einen strahlungsemittierenden Halbleiterbauelements während der Impulsdauer nur innerhalb eines vorgegebenen Strahlungsflusstoleranzbandes verändert. Insbesondere wird der einzustellende Verlauf des elektrischen Betriebsstroms derart ermittelt, dass der Strahlungsfluss des mindestens einen strahlungsemittierenden Halbleiterbauelements im Wesentlichen konstant ist. Dies hat den Vorteil, dass das mindestens eine strahlungsemittierende Halbleiterbauelement dadurch besonders gut für Anwendungen geeignet ist, bei denen das mindestens eine strahlungsemittierende Halbleiterbauelement im Impulsbetrieb betrieben wird und bei denen eine hohe Gleichmäßigkeit und Schwankungsarmut des Strahlungsflusses während der Impulsdauer gefordert wird.In an advantageous embodiment of the second aspect, the course of the electrical operating current to be set is determined such that a radiation flux of the at least one radiation-emitting semiconductor component changes during the pulse duration only within a predetermined radiation flux tolerance band. In particular, the course of the electrical operating current to be set is determined such that the radiation flux of the at least one radiation-emitting semiconductor component is substantially constant. This has the advantage that the at least one radiation-emitting Semiconductor component is thus particularly well suited for applications in which the at least one radiation-emitting semiconductor device is operated in the pulse mode and in which a high uniformity and Schwaungsungsarmut the radiation flux during the pulse duration is required.
In einer weiteren vorteilhaften Ausgestaltung des zweiten Aspekts wird die Steuervorrichtung ausgebildet, einen impulsförmigen, elektrischen Schaltstrom zu erzeugen. Das Ermitteln des einzustellenden Verlaufs des Betriebsstroms umfasst, dass der einzustellende Verlauf eines elektrischen, während der Impulsdauer ansteigenden, Kompensationsstroms ermittelt wird, der den elektrischen Schaltstrom zum Erzeugen des elektrischen Betriebsstroms überlagert. Ferner wird die Steuervorrichtung so ausgebildet, dass der einzustellende Verlauf des Kompensationsstroms jeweils während der Impulsdauer eingestellt wird. Dies hat den Vorteil, dass der elektrische Schaltstrom und der elektrische Kompensationsstrom unabhängig voneinander einstellbar sind. Insbesondere ist der elektrische Schaltstrom sehr einfach rechteckförmig einstellbar.In a further advantageous embodiment of the second aspect, the control device is designed to generate a pulse-shaped, electrical switching current. Determining the course of the operating current to be set comprises determining the course to be set of an electrical compensation current rising during the pulse duration, which superimposes the electrical switching current for generating the electrical operating current. Furthermore, the control device is designed so that the course of the compensation current to be set is set in each case during the pulse duration. This has the advantage that the electrical switching current and the electrical compensation current can be set independently of one another. In particular, the electrical switching current is very simple adjustable rectangular.
In einer weiteren vorteilhaften Ausgestaltung des zweiten Aspekts wird eine Spannungs-Strom-Kennlinie und/oder eine Strahlungsfluss-Strom-Kennlinie und/oder eine Strahlungsfluss-Sperrschichttemperatur-Kennlinie ermittelt, die jeweils repräsentativ ist für das mindestens eine strahlungsemittierende Halbleiterbauelement. Abhängig von der Spannungs-Strom-Kennlinie und/oder Strahlungsfluss-Strom-Kennlinie und/oder Strahlungsfluss-Sperrschichttemperatur-Kennlinie wird der einzustellende Verlauf des elektrischen Betriebsstroms beziehungsweise des elektrischen Kompensationsstroms ermittelt. Die Kennlinien sind im Allgemeinen aus beispielsweise herstellerseitig zur Verfügung gestellten Kenndaten des mindestens einen strahlungsemittierenden Halbleiterbauelements bekannt oder sind einfach durch Messung ermittelbar. Durch Berücksichtigen mindestens einer der Kennlinien ist der einzustellende Verlauf des elektrischen Betriebsstroms beziehungsweise des elektrischen Kompensationsstroms präzise ermittelbar.In a further advantageous embodiment of the second aspect, a voltage-current characteristic and / or a radiation flux-current characteristic and / or a radiation flux-junction temperature characteristic is determined, which is in each case representative of the at least one radiation-emitting semiconductor component. Depending on the voltage-current characteristic and / or radiation flux-current characteristic and / or radiation flux junction temperature characteristic curve is the course to be set of the electrical operating current or the electric Compensating current determined. The characteristic curves are generally known from, for example, manufacturer-provided characteristics of the at least one radiation-emitting semiconductor component or can be determined simply by measurement. By taking into account at least one of the characteristic curves, the course to be set of the electrical operating current or of the electrical compensation current can be determined precisely.
In diesem Zusammenhang ist es vorteilhaft, wenn der einzustellende Verlauf des elektrischen Betriebsstroms beziehungsweise des elektrischen Kompensationsstroms ermittelt wird abhängig von einer Summe über mindestens einen Summanden der Form A * (1 - exp(-t/tau)). Eine Zeitkonstante tau wird jeweils ermittelt abhängig von dem zeitlichen Verlauf der thermischen Impedanz. Ein Faktor A wird jeweils ermittelt abhängig von der ermittelten Spannungs-Strom-Kennlinie und/oder der ermittelten Strahlungsfluss-Strom-Kennlinie und/oder der ermittelten Strahlungsfluss-Sperrschichttemperatur-Kennlinie. Die jeweilige Zeitkonstante tau und/oder der jeweilige Faktor A sind beispielsweise durch Approximation an einen vorgegebenen Verlauf des elektrischen Betriebsstroms beziehungsweise des elektrischen Kompensationsstroms ermittelbar, der durch ein physikalisches Modell des mindestens einen strahlungsemittierenden Halbleiterbauelements vorgegeben ist. Dem physikalischen Modell werden dazu vorzugsweise der zeitliche Verlauf der thermischen Impedanz und/oder die ermittelte Spannungs-Strom-Kennlinie und/oder die ermittelte Strahlungsfluss-Strom-Kennlinie und/oder die ermittelte Strahlungsfluss-Sperrschichttemperatur-Kennlinie zugeführt. Auf diese Weise ist der einzustellende Verlauf des elektrischen Betriebsstroms beziehungsweise des elektrischen Kompensationsstroms einfach mit der gewünschten Präzision ermittelbar.In this context, it is advantageous if the course to be set of the electrical operating current or of the electrical compensation current is determined as a function of a sum over at least one summand of the form A * (1-exp (-t / tau)). A time constant tau is determined in each case depending on the time characteristic of the thermal impedance. A factor A is determined in each case depending on the determined voltage-current characteristic and / or the determined radiation flux-current characteristic and / or the determined radiation flux-junction temperature characteristic. The respective time constant tau and / or the respective factor A can be determined, for example, by approximation to a predetermined course of the electrical operating current or of the electric compensation current, which is predetermined by a physical model of the at least one radiation-emitting semiconductor component. For this purpose, the temporal profile of the thermal impedance and / or the determined voltage-current characteristic and / or the determined radiation flux-current characteristic and / or the determined radiation flux-junction temperature characteristic curve are preferably supplied to the physical model. In this way, the course to be set of the electrical operating current or the electrical Compensating current easily determined with the desired precision.
Ausführungsbeispiele der Erfindung sind im Folgenden anhand der schematischen Zeichnungen erläutert. Es zeigen:
Figur 1- eine Strahlungsfluss-Sperrschichttemperatur-Kennlinie, eine Strahlungsfluss-Strom-Kennlinie und ein Strahlungsfluss-Strom-Zeit-Diagramm,
Figur 2- einen Verlauf einer thermischen Impedanz,
- Figur 3
- ein Ausschnitt aus dem Strahlungsfluss-Strom-Zeit-Diagramm,
- Figur 4
- ein erstes Strom-Zeit-Diagramm,
Figur 5- ein zweites Strom-Zeit-Diagramm,
Figur 6- eine Steuervorrichtung und ein strahlungsemittierendes Halbleiterbauelement,
- Figur 7
- ein erstes Ablaufdiagramm und
- Figur 8
- ein zweites Ablaufdiagramm.
- FIG. 1
- a radiant flux junction temperature characteristic, a radiant flux-current characteristic and a radiant flux-current-time diagram,
- FIG. 2
- a course of a thermal impedance,
- FIG. 3
- a section of the radiation flux-current-time diagram,
- FIG. 4
- a first current-time diagram,
- FIG. 5
- a second current-time diagram,
- FIG. 6
- a control device and a radiation-emitting semiconductor component,
- FIG. 7
- a first flowchart and
- FIG. 8
- a second flowchart.
Elemente gleicher Konstruktion oder Funktion sind figurenübergreifend mit den gleichen Bezugszeichen versehen.Elements of the same construction or function are provided across the figures with the same reference numerals.
Messungen haben gezeigt, dass ein Strahlungsfluss Φe eines strahlungsemittierenden Halbleiterbauelements 1 in einem Impulsbetrieb während einer Impulsdauer PD abnimmt. Die Impulsdauer PD umfasst dabei für jeden Impuls eine Zeitdauer zwischen einer Einschaltphase und einer Ausschaltphase. Während der Einschaltphase und der Ausschaltphase verändert sich der Strahlungsfluss Φe aufgrund eines Einschaltvorgangs beziehungsweise eines Ausschaltvorgangs. Während der Impulsdauer PD soll der Strahlungsfluss Φe jedoch im Wesentlichen konstant sein.Measurements have shown that a radiation flux Φe of a radiation-emitting
Jedoch steigt mit steigendem Betriebsstrom If im Allgemeinen auch die Sperrschichttemperatur Tj des strahlungsemittierenden Halbleiterbauelements 1. Dies gilt insbesondere dann, wenn die Impulsdauer PD genügend lang ist, das heißt ein Arbeitszyklus in dem Impulsbetrieb genügend groß ist, um das Erwärmen des strahlungsemittierenden Halbleiterbauelements 1 zu bewirken. Aufgrund des in der Strahlungsfluss-Sperrschichttemperatur-Kennlinie gezeigten Zusammenhangs kann der Strahlungsfluss Φe durch Erhöhen des Betriebsstroms If daher nicht beliebig erhöht werden und sinkt sogar bei zu großem Betriebsstrom If und zu langer Impulsdauer PD beziehungsweise zu großem Arbeitszyklus.However, as the operating current If generally increases, so does the junction temperature Tj of the radiation-emitting
Abhängig von der Strahlungsfluss-Sperrschichttemperatur-Kennlinie, der Strahlungsfluss-Strom-Kennlinie und abhängig von einem zeitlichen Verlauf einer thermischen Impedanz Zth des strahlungsemittierenden Halbleiterbauelements 1, der in
Das Strahlungsfluss-Strom-Zeit-Diagramm ist beispielsweise ermittelbar durch ein physikalisches Modell des strahlungsemittierenden Halbleiterbauelements 1, das insbesondere ein Elektro-Thermo-Optisches Modell ist, in dem die relevanten elektrischen, die thermischen und die optischen Größen geeignet miteinander verknüpft sind. Zu den elektrischen Größen gehören beispielsweise der Betriebsstrom If, der durch das strahlungsemittierende Halbleiterbauelement 1 fließt, und eine Spannung, die über dem strahlungsemittierenden Halbleiterbauelement 1 abfällt. Zu den thermischen Größen gehören beispielsweise eine thermische Leistung sowie thermische Widerstände und thermische Kapazitäten, die durch die Materialien und deren Anordnung in dem strahlungsemittierenden Halbleiterbauelement 1 vorgegeben sind. Zu den optischen Größen gehört beispielsweise der Strahlungsfluss Φe. Es können auch weitere oder andere Größen in dem physikalischen Modell berücksichtigt sein. Dem physikalischen Modell werden bevorzugt die Strahlungsfluss-Sperrschichttemperatur-Kennlinie, die Strahlungsfluss-Strom-Kennlinie, der Verlauf der thermischen Impedanz Zth und gegebenenfalls eine Spannungs-Strom-Kennlinie vorgegeben. In der nicht dargestellten Spannungs-Strom-Kennlinie ist die Spannung, die über dem strahlungsemittierenden Halbleiterbauelement abfällt, über den Betriebsstrom If aufgetragen.The radiation flux-current-time diagram can be determined, for example, by a physical model of the radiation-emitting
Die Kennlinien und der zeitliche Verlauf der thermischen Impedanz Zth sind beispielsweise durch Messen ermittelbar. Der zeitliche Verlauf der thermischen Impedanz Zth ist beispielsweise durch einen Aufheiz- oder Abkühlvorgang ermittelbar und ist abhängig von den thermischen Widerständen und den thermischen Kapazitäten des strahlungsemittierenden Halbleiterbauelements 1. Die Kennlinien und der Verlauf der thermischen Impedanz Zth sind charakteristisch für das jeweilige strahlungsemittierende Halbleiterbauelement 1.The characteristics and the time profile of the thermal impedance Zth can be determined, for example, by measuring. The time profile of the thermal impedance Zth can be determined, for example, by a heating or cooling process and is dependent on the thermal resistances and the thermal capacitances of the radiation-emitting
Dem Strahlungsfluss-Strom-Zeit-Diagramm in
Bevorzugt wird der Verlauf des einzustellenden Betriebsstroms If als Überlagerung, das heißt als Summe, eines elektrischen Schaltstroms Is und eines elektrischen Kompensationsstroms Ik ermittelt, eingestellt und erzeugt, zum Kompensieren des Abfalls des Strahlungsflusses Φe aufgrund der Erwärmung während der jeweiligen Impulsdauer PD. Der elektrische Schaltstrom Is wird vorzugsweise rechteckförmig vorgesehen und entspricht daher Rechteckimpulsen. Der elektrische Schaltstrom Is ist während der Impulsdauer PD vorzugsweise im Wesentlichen konstant und dient zum Einschalten des strahlungsemittierenden Halbleiterbauelements 1 während der Impulsdauer PD und zum ansonsten Ausschalten des strahlungsemittierenden Halbleiterbauelements 1. Der elektrische Kompensationsstrom Ik ist so vorgesehen, dass dieser während der Impulsdauer PD ansteigt, um den Abfall des Strahlungsflusses Φe aufgrund der Erwärmung des strahlungsemittierenden Halbleiterbauelements 1 zu kompensieren. Entsprechend dem elektrischen Kompensationsstrom Ik steigt auch der elektrische Betriebsstrom If während der Impulsdauer PD an.Preferably, the profile of the operating current If to be set is determined, set and generated as an overlay, that is to say as a sum, of an electrical switching current Is and of an electric compensation current Ik, in order to compensate for the drop in the radiation flux .phi.e due to the heating during the respective pulse duration PD. The electrical switching current Is is preferably provided rectangular and therefore corresponds to rectangular pulses. The electrical switching current Is is preferably substantially constant during the pulse duration PD and serves for switching on the radiation-emitting
Eine Zeitkonstante tau wird jeweils ermittelt abhängig von dem zeitlichen Verlauf der thermischen Impedanz Zth. Wird die Anzahl der Summanden gleich einer Anzahl thermischer Widerstands-Kapazitätsglieder oder thermischer RC-Glieder des strahlungsemittierenden Halbleiterbauelements 1 gewählt, die den Verlauf der thermischen Impedanz Zth prägen, dann entspricht die jeweilige Zeitkonstante tau einer jeweiligen Zeitkonstante, die durch jeweils eines der thermischen RC-Glieder des strahlungsemittierenden Halbleiterbauelements 1 vorgegebenen sind. Die thermischen widerstände und die thermischen Kapazitäten, die die thermischen RC-Glieder bilden, und somit auch die zugehörigen Zeitkonstanten sind abhängig von dem Verlauf der thermischen Impedanz Zth ermittelbar. Ferner wird ein Faktor A jeweils ermittelt abhängig von der Spannungs-Strom-Kennlinie und/oder der Strahlungsfluss-Strom-Kennlinie und/oder der Strahlungsfluss-Sperrschichttemperatur-Kennlinie. Aufgrund der Einfachheit der Funktion der einzelnen Summanden kann der Verlauf des approximierten Kompensationsstroms Ia sehr einfach erzeugt werden, zum Beispiel mittels entsprechend ausgebildeter elektrischer Widerstands-Kapazitäts-Glieder, die auch als elektrische RC-Glieder bezeichnet werden können.A time constant tau is determined in each case depending on the time characteristic of the thermal impedance Zth. If the number of summands equal to a number of thermal resistance capacitance elements or thermal RC elements of the radiation-emitting
Ein Schritt S3 kann vorgesehen sein, in dem die Steuervorrichtung 2 so ausgebildet wird, dass der impulsförmige, vorzugsweise rechteckförmige, elektrische Schaltstrom Is erzeugbar ist. Ein Schritt S4 kann vorgesehen sein, in dem der einzustellende Verlauf des während der Impulsdauer PD ansteigenden, elektrischen Kompensationsstroms Ik ermittelt wird, gegebenenfalls in Form des approximierten Kompensationsstroms Ia. Das Ermitteln erfolgt abhängig von dem erfassten Verlauf der thermischen Impedanz Zth. Bevorzugt erfolgt das Ermitteln mittels des physikalischen Modells des strahlungsemittierenden Halbleiterbauelements 1, dem der erfasste Verlauf der thermischen Impedanz Zth vorgegeben wird. Dazu wird beispielsweise der Verlauf der gewünschten Höhenlinie in dem Strahlungsfluss-Strom-Zeit-Diagramm ermittelt und gegebenenfalls die Approximation des approximierten Kompensationsstroms Ia durchgeführt. Durch die Approximation werden beispielsweise Parameter ermittelt, die zum Einstellen des Kompensationsstroms Ik nutzbar sind. Das Ermitteln des einzustellenden Verlaufs des Kompensationsstroms Ik kann jedoch auch anders erfolgen.A step S3 may be provided, in which the
Ferner kann ein Schritt S5 vorgesehen sein, in dem der einzustellende Betriebsstrom If als Überlagerung oder Summe des Schaltstroms Is und des Kompensationsstroms Ik ermittelt wird. In einem Schritt S6 wird die Steuervorrichtung 2 so ausgebildet, dass der einzustellende Betriebsstrom If während des Betriebs erzeugbar ist. Dies kann beispielsweise durch Ausbilden einer elektrischen Schaltungsanordnung und geeignetes Dimensionieren von elektrischen RC-Gliedern erfolgen. Es ist jedoch ebenso möglich, die Parameter oder Werte, die den einzustellenden Verlauf des Kompensationsstroms Ik beziehungsweise des Betriebsstroms If repräsentieren, digital in einem Speicher zu speichern und während der Impulsdauer PD zum Einstellen des Kompensationsstroms Ik beziehungsweise des Betriebsstroms If zu nutzen, beispielsweise durch Wandeln einer Folge von gespeicherten Werten mittels eines Digital-Analog-Wandlers. Eine weitere Möglichkeit besteht beispielsweise darin, einen Funktionsgenerator vorzusehen, der ausgebildet ist, ausgangsseitig einen Signalverlauf entsprechend dem Verlauf des einzustellenden Betriebsstroms If oder des einzustellenden Kompensationsstroms Ik bereitzustellen. Die Steuervorrichtung 2 kann in dem Schritt S6 jedoch auch anders ausgebildet werden.Furthermore, a step S5 may be provided in which the operating current If to be set is determined as a superposition or sum of the switching current Is and the compensation current Ik. In a step S6, the
Das Verfahren endet in einem Schritt S7. Es kann auch vorgesehen sein, den einzustellenden Betriebsstrom If abhängig von dem ermittelten Verlauf der thermischen Impedanz Zth in einem Schritt S8 zu ermitteln, ohne dass dazu der Schaltstrom Is und der Kompensationsstrom Ik ermittelt werden müssen. Der Schritt S8 kann daher gegebenenfalls die Schritte S3 bis S5 ersetzen.The method ends in a step S7. It can also be provided to determine the operating current If to be set depending on the determined characteristic of the thermal impedance Zth in a step S8, without the switching current Is and the compensation current Ik being determined for this purpose have to. The step S8 may therefore optionally replace the steps S3 to S5.
Das Steuerverfahren beginnt in einem Schritt S10. In einem Schritt S11 wird der impulsförmige, vorzugsweise rechteckförmige, elektrische Schaltstrom Is erzeugt. In einem Schritt S12 wird der einzustellende Kompensationsstrom Ik eingestellt, zum Beispiel in Form des approximierten Kompensätionsstroms Ia, und entsprechend erzeugt. In einem Schritt S13 wird der Betriebsstrom If als Überlagerung oder Summe des Schaltstrome Is und des Kompensationsstroms Ik erzeugt und in einem Schritt S14 an das mindestens eine strahlungsemittierende Halbleiterbauelement 1 ausgegeben. Das Steuerverfahren endet in einem Schritt S15. Es kann auch vorgesehen sein, den ansteigenden Betriebsstrom If in einem Schritt S16 zu erzeugen, ohne dass dazu der Schaltstrom Is und der Kompensationsstrom Ik erzeugt werden muss. Der Schritt S16 kann daher gegebenenfalls die Schritte S11 bis S13 ersetzen.The control process starts in a step S10. In a step S11, the pulse-shaped, preferably rectangular, electrical switching current Is is generated. In a step S12, the compensating current Ik to be set is set, for example in the form of the approximated compensating current Ia, and generated accordingly. In a step S13, the operating current If is superimposed or sum of the switching current Is and the compensation current Ik generated and output in a step S14 to the at least one radiation-emitting
Die Erfindung ist nicht durch die Beschreibung anhand der Ausführungsbeispiele beschränkt. Vielmehr umfasst die Erfindung jedes neue Merkmal sowie jede Kombination von Merkmalen, was insbesondere jede Kombination von Merkmalen in den Patentansprüchen beinhaltet, auch wenn dieses Merkmal oder diese Kombination selbst nicht explizit in den Patentansprüchen oder Ausführungsbeispielen angegeben ist.The invention is not limited by the description with reference to the embodiments. Rather, the invention encompasses any novel feature as well as any combination of features, including in particular any combination of features in the claims, even if this feature or combination itself is not explicitly stated in the patent claims or exemplary embodiments.
Diese Patentanmeldung beansprucht die Priorität der deutschen Patentanmeldung
Claims (12)
- Control method,
in which a pulsed electric operating current (If) that rises during a pulse duration (PD) is generated for operating at least one radiation-emitting semiconductor component (1). - Control method according to Claim 1,
in which the electric operating current (If) is generated in such a way that a radiation flux (Φe) of the at least one radiation-emitting semiconductor component (1) changes only within a predetermined radiation flux tolerance band (Φetol) during the pulse duration (PD). - Control method according to either of Claims 1 and 2, in which- a pulsed electric switching current (Is) is generated, and- an electric compensation current (Ik) is generated, which rises during the pulse duration (PD) and which is superposed on the electric switching current (Is) in order to generate the electric operating current (If) of the at least one radiation-emitting semiconductor component (1).
- Control method according to one of the preceding claims,
in which a profile of the electric operating current (If) and respectively of the electric compensation current (Ik) is generated depending on a sum formed using at least one summand of the form
where a time constant tau and a factor A are predetermined in each case. - Control device, which is designed for generating a pulsed electric operating current (If) that rises during a pulse duration (PD) for operating at least one radiation-emitting semiconductor component (1).
- Control device according to Claim 5,
which is designed for generating the electric operating current (If) in such a way that a radiation flux (Φe) of the at least one radiation-emitting semiconductor component (1) changes only within a predetermined radiation flux tolerance band (Φetol) during the pulse duration (PD). - Control device according to either of Claims 5 and 6,
which together with the at least one radiation-emitting semiconductor component (1) is formed as a common structural unit. - Method for producing a control device (2) for operating at least one radiation-emitting semiconductor component (1) by means of a pulsed electric operating current (If) that rises during a pulse duration (PD), in which- a temporal profile of a thermal impedance (Zth) representative of the at least one radiation-emitting semiconductor component (1) is determined,- a profile of the operating current (If) that is to be set is determined depending on the determined temporal profile of the thermal impedance (Zth), and- the control device (2) is designed such that the profile of the electric operating current (If) that is to be set is set in each case during the pulse duration (PD).
- Method according to Claim 8,
in which the profile of the electric operating current (If) that is to be set is determined in such a way that a radiation flux (Φe) of the at least one radiation-emitting semiconductor component (1) changes only within a predetermined radiation flux tolerance band (Φetol) during the pulse duration (PD). - Method according to either of Claims 8 and 9,
in which- the control device (2) is designed to generate a pulsed electric switching current (Is),- determining the profile of the operating current (If) that is to be set comprises determining a profile to be set of an electric compensation current (Ik) that rises during the pulse duration (PD) and is superposed on the electric switching current (Is) in order to generate the electric operating current (If), and- the control device (2) is designed such that the profile of the compensation current (Ik) that is to be set is set in each case during the pulse duration (PD). - Method according to one of Claims 8 to 10,
in which- a voltage-current characteristic curve and/or a radiation flux-current characteristic curve and/or a radiation flux-junction temperature characteristic curve is determined, which is in each case representative of the at least one radiation-emitting semiconductor component (1),- the profile to be set of the electric operating current (If) and respectively of the electric compensation current (Ik) is determined depending on the voltage-current characteristic curve and/or radiation flux-current characteristic curve and/or radiation flux-junction temperature characteristic curve. - Method according to Claim 11,
in which the profile to be set of the electric operating current (If) and respectively of the electric compensation current (Ik) is determined depending on a sum formed using at least one summand of the form
where- a time constant tau is in each case determined depending on the temporal profile of the thermal impedance (Zth), and- a factor A is in each case determined depending on the voltage-current characteristic curve determined and/or the radiation flux-current characteristic curve determined and/or the radiation flux-junction temperature characteristic curve determined.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102007009532A DE102007009532A1 (en) | 2007-02-27 | 2007-02-27 | Radiation-emitting semiconductor component i.e. red luminous LED, controlling method for operating component, involves generating pulse-shaped electrical operating current for operating radiation-emitting semiconductor component |
PCT/DE2008/000290 WO2008104152A1 (en) | 2007-02-27 | 2008-02-15 | Control method, control device, and method for the production of the control device |
Publications (2)
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EP2062461A1 EP2062461A1 (en) | 2009-05-27 |
EP2062461B1 true EP2062461B1 (en) | 2013-04-24 |
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EP08706896.1A Active EP2062461B1 (en) | 2007-02-27 | 2008-02-15 | Control method, control device, and method for the production of the control device |
Country Status (8)
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US (1) | US8519633B2 (en) |
EP (1) | EP2062461B1 (en) |
JP (1) | JP5502495B2 (en) |
KR (1) | KR101486846B1 (en) |
CN (1) | CN101675708B (en) |
DE (1) | DE102007009532A1 (en) |
TW (1) | TW200901827A (en) |
WO (1) | WO2008104152A1 (en) |
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DE102013107520A1 (en) | 2013-07-16 | 2015-01-22 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | LED lamp for a luminaire and operating method for this luminaire |
AT517625A1 (en) * | 2015-09-07 | 2017-03-15 | Mat Center Leoben Forschung Gmbh | Method and device for monitoring a semiconductor module |
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US3705316A (en) * | 1971-12-27 | 1972-12-05 | Nasa | Temperature compensated light source using a light emitting diode |
JPS6151887A (en) | 1984-08-21 | 1986-03-14 | Nec Corp | Driving device for semiconductor laser |
JP3725235B2 (en) * | 1996-03-29 | 2005-12-07 | 富士通株式会社 | Light emitting element driving circuit and light emitting device having the same |
US5907569A (en) * | 1997-05-28 | 1999-05-25 | Lucent Technologies Inc. | Circuit for controlling the output power of an uncooled laser or light emitting diode |
JP3449898B2 (en) * | 1997-10-16 | 2003-09-22 | 富士通株式会社 | Light emitting element drive circuit |
US6198497B1 (en) * | 1998-06-03 | 2001-03-06 | Hewlett-Packard | Adjustment of a laser diode output power compensator |
CA2345731A1 (en) * | 1998-09-29 | 2000-04-06 | Mallinckrodt Inc. | Oximeter sensor with encoded temperature characteristic |
DE19912463A1 (en) * | 1999-03-19 | 2000-09-28 | Sensor Line Ges Fuer Optoelekt | Process for stabilizing the optical output power of light-emitting diodes and laser diodes |
DE10040155A1 (en) * | 2000-08-17 | 2002-03-07 | Westiform Holding Ag Niederwan | Contour lighting for applying as luminous advertising or neon signs, comprises multiple luminous diodes supplied with voltage source and temperature sensor for controlling constant-current circuit |
US6930737B2 (en) * | 2001-01-16 | 2005-08-16 | Visteon Global Technologies, Inc. | LED backlighting system |
US7262752B2 (en) * | 2001-01-16 | 2007-08-28 | Visteon Global Technologies, Inc. | Series led backlight control circuit |
JP2003008138A (en) * | 2001-06-13 | 2003-01-10 | Motorola Inc | Laser diode control unit |
JP2004087595A (en) | 2002-08-23 | 2004-03-18 | Dainippon Screen Mfg Co Ltd | Light emitting element driving circuit |
JP2005303091A (en) | 2004-04-13 | 2005-10-27 | Sanyo Electric Co Ltd | Led module |
DE102004018912A1 (en) * | 2004-04-15 | 2005-11-03 | Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH | Device for light control |
KR101249025B1 (en) | 2004-10-22 | 2013-03-29 | 코닌클리즈케 필립스 일렉트로닉스 엔.브이. | Method for driving a led based lighting device |
JP4566692B2 (en) * | 2004-10-28 | 2010-10-20 | シャープ株式会社 | LIGHT EMITTING DIODE DRIVING DEVICE AND OPTICAL TRANSMISSION DEVICE HAVING THE SAME |
US7443413B2 (en) * | 2005-10-21 | 2008-10-28 | Hewlett-Packard Development Company, L.P. | Laser diode modulator and method of controlling laser diode modulator |
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US8253666B2 (en) * | 2007-09-21 | 2012-08-28 | Point Somee Limited Liability Company | Regulation of wavelength shift and perceived color of solid state lighting with intensity and temperature variation |
-
2007
- 2007-02-27 DE DE102007009532A patent/DE102007009532A1/en not_active Withdrawn
-
2008
- 2008-02-15 US US12/528,005 patent/US8519633B2/en active Active
- 2008-02-15 CN CN200880006346.5A patent/CN101675708B/en active Active
- 2008-02-15 JP JP2009551097A patent/JP5502495B2/en active Active
- 2008-02-15 KR KR1020097016131A patent/KR101486846B1/en active IP Right Grant
- 2008-02-15 EP EP08706896.1A patent/EP2062461B1/en active Active
- 2008-02-15 WO PCT/DE2008/000290 patent/WO2008104152A1/en active Application Filing
- 2008-02-27 TW TW097106867A patent/TW200901827A/en unknown
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KR20090115716A (en) | 2009-11-05 |
KR101486846B1 (en) | 2015-01-28 |
JP2010519774A (en) | 2010-06-03 |
EP2062461A1 (en) | 2009-05-27 |
WO2008104152A1 (en) | 2008-09-04 |
CN101675708A (en) | 2010-03-17 |
DE102007009532A1 (en) | 2008-08-28 |
US20100090610A1 (en) | 2010-04-15 |
JP5502495B2 (en) | 2014-05-28 |
TW200901827A (en) | 2009-01-01 |
CN101675708B (en) | 2014-05-07 |
US8519633B2 (en) | 2013-08-27 |
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