JP5174529B2 - LED dimming lighting device, vehicle lighting device, lighting fixture - Google Patents

Description

  The present invention relates to an LED dimming lighting device, a vehicle lighting device using the same, and a lighting fixture.

  In recent years, mass production of white light emitting diodes (hereinafter referred to as “LEDs”) has been actively carried out, and their uses have also diversified. In the field of vehicles, white LEDs are used in the passenger compartment, and headlights and daytime running lamps (daytime lighting) are being developed with high brightness.

  The LED has a longer life than the incandescent light bulb, has a quick response, can be mounted in a compact structure, and can easily make various colors without a filter depending on the application. And since lighting fixtures, such as a lamp, are thin and can be mounted three-dimensionally, there is an advantage that a free design that does not restrict the shape such as a car design is possible.

  The luminous flux of the LED has a strong correlation with the forward current If. When the forward current If is increased, the light flux increases monotonously. Dimming can be easily performed by this current change. However, when the DC current of the forward current If is changed, the hue may change. For example, a white LED using a yellow phosphor for a blue LED changes its color coordinate depending on the magnitude of the current. When the current decreases, the hue shifts in the yellow direction, and when the current increases, the color tends to shift in the blue direction.

  In order to reduce this color shift, a driving method using pulse width modulation (PWM) control has been proposed. This is a method of dimming by turning on / off the current flowing through the LED at a period in which humans cannot recognize blinking and changing the time width of the on, and the current value at the time of on is near the rating of the LED The constant current is controlled by the value.

  FIG. 21 shows a conventional example. In FIG. 21, the LED load 2 has a plurality of light emitting diodes connected in series. Reference numeral 3 denotes an LED lighting circuit, and the resistor R is a current limiting element. The resistor R and the LED load 2 are connected in series with the DC power source 1a and the switch element S1. A forward current If which is a current flowing through the LED load 2 has a waveform shown in FIG. During the period T0 to t1, the switch element S1 is turned on to flow the forward current If, and during the period from t1 to the next t0, the switch element S1 is turned off and the forward current If does not flow. Is. In many cases, the switching frequency is used at several hundred Hz. The peak value If1 of the forward current If is set near the rating of the LED.

The dimming signal unit 4 sets the period T1 during which the switch element S1 is on. Since the forward current If flows a sufficient current If1 (current near the rated value) during that period, even if the ON period T1 of the switch element S1 in FIG. 22 is changed from t0 to t1 ′ as indicated by an arrow, Dimming shift is small and dimming is possible. This type of lighting circuit is disclosed in Patent Document 1.
JP 2005-5112 A

  However, due to the increase in output of white LEDs, the forward current If is conventionally about several tens of mA for use in signal systems, but the forward current If is several for illumination uses (uses that illuminate objects, etc.). A large current in the region of 100 mA to several A is obtained. When the LED is driven with such a current in the waveform of FIG. 22, it becomes a use state similar to that of flashing the switch with a very fast operation, and by repeated expansion and contraction due to heat, a phosphor specific to the white LED is obtained. The thermal stress on the mounting surface becomes a state that cannot be ignored.

  As described above, in the conventional method, dimming can be performed while reducing the shift in hue, but since the forward current If of the LED intermittently flows with a large current, the LED element is subjected to thermal stress, The phosphor attached to the LED element gives a mechanical structural stress from a thermal stress, and the LED may have a short life.

  In addition, although a general diode has a large current withstand capability, a white LED is a diode, but has a structure in which a phosphor is closely attached to the surface for wavelength conversion, so the periphery of the diode chip is very delicate. In addition, microscopic expansion and contraction promotes deterioration of the phosphor, such as microcracks or exfoliation in extreme cases.

  The present invention has been made in view of the above points, and in an LED dimming lighting device that performs dimming control by changing the luminous flux of the LED, dimming is performed while reducing the shift of the color emitted by the LED. An object of the present invention is to provide a lighting circuit that can reduce the thermal stress caused by the current flowing through the LED, and achieve a long life and high reliability of the LED.

The invention according to claim 1, in order to solve the above problem, as shown in FIGS. 1 and 2, an LED load 2 consisting of one or more LED, for adjusting the light output of the L ED load 2 and a dimming signal and outputs the dimming signal unit 4, the power supply 1a receives the dimming signals from the dimming signal unit 4, the 1b or et L ED load 2 and the first current If1 second current If2 The lighting circuits 3a and 5 are alternately supplied. The first current If1 is a current in the vicinity of the rating at which the LED load 2 emits a predetermined color, and the second current If2 is a dimming signal from the dimming signal unit 4. In response , the LED has a variable current, the LED has an LED element and a phosphor attached to the LED element, and the lighting circuits 3a and 5 intermittently supply the current as shown in FIGS. A constant whose magnitude is controlled by receiving a dimming signal from the first lighting circuit 3a and the dimming signal unit 4 to be output. A second lighting circuit 5 that always outputs a current, and an intermittent current supplied from the first lighting circuit 3a and a constant current supplied from the second lighting circuit 5 are constantly superimposed. those characterized that you alternately supplied to the LED load 2 and the first current If1 a second current If2 Te.

The invention of Reference Example 1 different from the present application includes an LED load 2 composed of one or a plurality of LEDs, a dimming signal unit 4 that outputs a dimming signal for adjusting the light output of the LED load 2, and dimming A lighting circuit 3a, 5 that alternately receives a first current If1 and a second current If2 from the power source 1a, 1b to the LED load 2 in response to a dimming signal from the signal unit 4 is provided, and the first current If1. is LED load 2 and the rated current neighborhood emitting a predetermined color, the second current If2 is current receiving dimming signals from the dimming signal unit 4 is variable, as shown in FIGS. 4 and 5, lit circuit 5a, and supplying the time division manner L ED load 2 and the first current If1 the second current If2.

According to a second aspect of the present invention, in the first aspect of the invention, as shown in FIGS. 6 and 7, the first lighting circuit 3a is switched from the first DC power source 1a intermittently to the current limiting resistor R. a circuit for supplying intermittently electric current in L ED load 2 via the element S2, the second lighting circuit 5b, L ED load 2 two tone from the second DC power source 1b via the DC-DC converter circuit a circuit for supplying a constant-flow magnitude receiving light signal unit 4 dimming signal is controlled, the output current If2 of the DC-DC converter circuit, the dimming signal from the dimming signal 4 It is characterized by being variable upon receipt.

The invention Example 2, in the invention of Example 1, 8, 9, lit. circuit 5a, a DC-DC converter circuit having an output current feedback function, the command value Vt of the output current The command value generation unit receives the dimming signal from the dimming signal unit 4 and the DC-DC converter circuit temporally changes the first current and the second current. and generating a current command value Vt to output the L ED load 2 alternately.

In the invention of the reference example 3, in the invention of the reference example 2 , as shown in FIGS. 10 and 11, the output current If of the DC-DC converter circuit is predetermined during the period in which the first current and the second current are switched. It is characterized by a smooth change with the inclination of.

The invention Reference Example 4, in the invention of Example 2, as shown in FIG. 13, FIG. 14, an auxiliary power source for outputting a high DC voltage constantly than the sum of the forward voltage of the L ED load 2, this auxiliary power supply characterized in that the constant weak current to the pressurized et L ED load 2 by adding the current limiting element Ra of the supplied high impedance.

The invention of Reference Example 5 is characterized in that , in the invention of Reference Example 2 , as shown in FIGS. 15 to 17, the second current has a current waveform that decreases continuously or stepwise over time. And

A third aspect of the present invention is a vehicle lighting device including the LED dimming lighting device according to the first or second aspect (FIG. 20).

According the invention of claim 4 is a luminaire comprising a LED dimming lighting apparatus mounting serial to claim 1 or claim 2.

  According to the present invention, focusing on the current waveform that flows when the LED is dimmed, the current waveform of the second direct current component is superimposed on the conventional PWM control, thereby suppressing a rapid current change flowing in the LED. It is possible to reduce the thermal stress and achieve long life, high reliability, and high quality. Even with dimming control, there is little shift in hue, and due to a sudden current change to the LED Thermal stress can be reduced, and long life and high reliability can be secured. In addition, since dimming can be performed by controlling the second current, dimming control can be performed in consideration of individual characteristics of the LED, and a lighting circuit that can handle a plurality of types of LEDs having different characteristics can be provided. The lighting circuit can be shared.

(Basic configuration)
FIG. 1 shows an LED current waveform in the LED dimming lighting device of the present invention. The temporal change of the forward current If flowing through the LED is shown. In the first period T1, the first forward current If1 near the rating is passed, and in the second period T2, the second forward current If2 is passed. In the second period T2, the second forward current If is passed. Dimming is achieved by controlling the magnitude of If2. FIG. 1 shows a state in which the second forward current If2 is increased or decreased by the up and down arrows in the second period T2.

In the control example of FIG. 1, dimming is performed by flowing a current lower than that in the first period T1 in the second period T2, and the forward current If2 that flows in the second period T2 during full lighting. Is substantially the same value as the forward current If1 in the first period T1. The second forward current If2 is changed abruptly from the first forward current If1, but may be gradually changed as shown in FIGS. Further, a current rest period (FIGS. 16 and 17) may be provided in the second half of the second period T2. Here, as shown in FIG. 22 (conventional example), suddenly reducing the current from a large current (first forward current If1) to zero is problematic from the viewpoint of thermal stress (expansion and contraction stress). However, as shown in FIGS. 15 and 16, the control for gradually reducing the current during dimming to zero is relatively less stressful.
As described above, the present invention achieves good dimming while reducing the thermal stress on the LED with the second forward current If2.

  There are two methods for superimposing the second forward current on the LED. A method of constantly superimposing on the LED is shown in FIGS. 4 and 5 show a method of superimposing the LEDs in a time division manner.

  First, the control method of FIG. 2 and FIG. In FIG. 2, 3a is a lighting circuit that outputs a first forward current If1, 5 is a lighting circuit that outputs a second forward current If2, and 1a and 1b are respective power supplies. In this configuration, the first forward current If1 and the second forward current If2 are supplied to the LED load 2 in parallel, and the second forward current If2 is constantly superimposed. The second lighting circuit 5 receives a signal from the dimming signal unit 4 and controls the magnitude of the second forward current If2. FIG. 3 shows the first forward current If1, the second forward current If2, and the total forward current If obtained by combining these. The forward current If is superimposed in parallel to the time axis. In this embodiment, in the first period T1, the first forward current If1 and the second forward current If2 overlap each other. The diodes D01 and D02 in FIG. 2 prevent wraparound, but may be connected as necessary.

  Next, the control methods of FIGS. 4 and 5 that are superimposed in a time division manner will be described. In FIG. 4, 5a is a lighting circuit, and other symbols are the same as those in FIG. FIG. 5 shows the first forward current If1, the second forward current If2, and the total forward current If obtained by combining them. The forward current If is superimposed in series on the time axis.

  2 and 4, the forward current If flowing through the LED load 2 is alleviated from a large current change as in the conventional case, so that thermal stress (expansion / shrinkage stress) on the LED is applied. Can be reduced.

(Embodiment 1)
A specific embodiment 1 of the present invention is shown in FIG. This embodiment is a specific example of FIG. In the lighting circuit 3a, the oscillation unit 22 generates a first period T1 and a second period T2 with a period T. The switch element S2 is operated by an on / off signal of the oscillation unit 22. When turned on, a forward current If1 determined by the voltage of the power source 1a and the resistor R flows. The lighting circuit 5b uses the configuration of a boost chopper circuit. The switching element S3 operates by receiving an ON / OFF signal of several hundred kHz from the PWM control circuit 21. The capacitor C1 obtains a higher DC voltage than the power source 1b. A forward current If2 is passed through the LED load 2 at this voltage. A current limiting resistor may be inserted in series with the diode D2. The value of the combined current of the forward currents If1 and If2 is set to be a current near the rating of the LED load 2.

  FIG. 7 shows a specific example of the PWM control circuit 21 and the dimming signal unit 4 of FIG. The input voltage of the voltage comparator 211 is changed by the variable resistor Rv of the dimming signal unit 4, and the switching element S <b> 3 is turned on / off by comparing the voltage with the voltage of the triangular wave oscillation unit 212. The oscillation frequency of the triangular wave oscillator 212 is a high frequency of several tens of kHz to several hundreds of kHz. When the variable resistance Rv is reduced, the input voltage to the voltage comparator 211 is increased, the on-duty of the output of the voltage comparator 211 is reduced, and the ON period of the switching element S3 is reduced, so that the voltage of the capacitor C1 is reduced, The forward current If2 to the LED load 2 is reduced, and dimming is possible.

The voltage comparator 213 is provided in order to protect the output voltage of the booster circuit 5b when the LED load 2 is opened or the like because the output voltage rises excessively. When the detection voltage obtained by dividing the voltage at the point a by the resistor becomes higher than the preset reference voltage Vref, the output of the voltage comparator 213 is inverted and the output of the gate circuit 214 is stopped.
The first forward current If1, the second forward current If2, and the total forward current If obtained by combining these are the same as the waveforms shown in FIG.

(Embodiment 2)
A second embodiment of the present invention is shown in FIGS. This embodiment is a specific example of FIG. The lighting circuit 5a in FIG. 8 uses a configuration of a flyback DC-DC converter circuit. When the switching element Q1 is on, current flows from the DC power source 1 to the primary winding of the transformer PT1, and energy is accumulated. At this time, the diode D is in a reverse blocking state. When the switching element Q1 is turned off, back electromotive force is generated in the secondary winding by the energy stored in the transformer PT1, the diode D is turned on, and the capacitor C2 is charged. The voltage of the capacitor C2 can be adjusted by increasing or decreasing the pulse width of the switching element Q1.

  The switching element Q1 is turned on / off by the drive unit 33, and its control signal is generated by the PWM control unit 32, the D / A converter 31, the microcomputer 30, the A / D converter 33, and the dimming signal unit 4. The voltage value of the dimming signal of the dimming signal unit 4 is converted from an analog signal to a digital signal by the A / D converter 33 and input to the microcomputer 30. The microcomputer 30 generates digital signal data Da (hexadecimal) as shown in FIG. The D / A converter 31 receives the digital signal data Da, converts it to a voltage value Vt of an analog signal as shown in FIG. 9B, and inputs it to the differential amplifier 321. The differential amplifier 321 amplifies the difference between the detection voltage value Vr of the forward current If detected by the current detection resistor R1 and the voltage value Vt of the analog signal, and the forward current If is compared with the voltage value Vt of the analog signal. When the detected voltage value Vr is low, the reference voltage of the voltage comparator 322 for PWM control is changed so as to increase the forward current If so that the ON period of the switching element Q1 increases. As a result, the voltage of the capacitor C2 is increased, so that the forward current If increases, and feedback control is performed so that there is no difference between the voltage value Vt of the analog signal and the detected voltage value Vr of the forward current If. The voltage comparator 322 sets the switching element Q <b> 1 on / off by comparing the reference voltage and the voltage of the triangular wave oscillating unit 323. The oscillation frequency of the triangular wave oscillating unit 323 is a high frequency of several tens kHz to several hundreds kHz.

  FIG. 9C shows a waveform of the forward current If in the present embodiment. The forward current If2 in the second period T2 is changed in conjunction with the signal of the dimming signal unit 4 and thereby dimmed. That is, the magnitude of the second forward current If2 is controlled by the change in the variable resistance Rv of the dimming signal unit 4. In this embodiment, by using the microcomputer 30, the forward current If2 in the second period T2 can be freely changed, so that dimming control with high accuracy can be performed.

(Embodiment 3)
A specific third embodiment of the present invention is shown in FIGS. The configuration of the flyback DC-DC converter circuit is the same as that of the second embodiment shown in FIG. In the third embodiment shown in FIG. 10, a filter circuit including a capacitor C3 and an inductor L2 is added to reduce high-frequency ripple and noise in the lighting circuit 5a. Also in this case, when dimming by changing the load current If abruptly as in the prior art, a transient voltage may be generated in the inductor L2. It needs to be relaxed. An example of the waveform of the forward current If of the LED load 2 in this embodiment is shown in FIG.

  Control is performed to gradually change the forward current If before and after the first period T1. This control may be performed by the control unit 34 shown in FIG. By using the microcomputer 30, the forward current If of FIG. 11 can be freely changed. By this control, the filter circuit for reducing noise and ripple can be sufficiently functioned, and can be realized with a small and simple configuration.

(Embodiment 3 ')
The embodiment of FIG. 12 is an embodiment in which a parallel circuit of a resistor Rs and a switching element S5 is connected in series with the LED load 2 of FIG. 10, and a loose contact occurs at the start of power on / off and the connection of the LED. When the switching element S5 is turned off, the forward current If is caused to flow through the LED load 2 via the resistor Rs, thereby suppressing the overcurrent. Also in other embodiments, the load circuit of FIG. 12 may be applied.

(Embodiment 4)

  A specific fourth embodiment of the present invention is shown in FIGS. In this embodiment, if the current is decreased during dimming and the applied voltage is too low, the operation may become unstable due to variations in the forward voltage Vf of each LED. A voltage higher than the total voltage (n × Vf) of the entire voltage Vf is applied from the lighting circuit 5c to the LED load 2 via a high impedance (resistance Ra). The LED load 2 is more stable than the case of no bias by biasing through a high impedance at a potential equal to or higher than the forward voltage Vf in consideration of the type and characteristics of the LED in accordance with the limitation and control of the current waveform. It is possible to realize various operations and control light, absorb variations in LEDs, and the like.

  A specific example of the lighting circuit 5c is shown in FIG. Normal operation is the same as in FIG. The voltage Vc4 of the capacitor C4 is set higher than the voltage across the LED load 2, and the resistor Ra is set so that a current of about several percent of the main forward current If flows. The voltage Vc4 of the capacitor C4 is preferably 1.2 times to 1.5 times the total voltage (n × Vf) of the forward voltage Vf of the LED load 2. Specific values of the resistor Ra and the voltage Vc4 may be set so that a stable operation of the LED load 2 can be realized. The voltage dividing circuit of the resistors R11 and R12 is a detection unit of an overvoltage prevention circuit for detecting a voltage rise at the terminal a and stopping the switching operation when the LED load 2 is opened due to poor terminal contact or the like. . Although the configuration of the overvoltage prevention circuit is not shown, it may be the same as that shown in FIG.

(Embodiment 5)
In the present embodiment, another control example will be described for the waveform of the second forward current If2 in the second period T2.
In the control example of FIG. 15, the second period T2 is controlled by a falling current waveform, and there is no current pause period, but the range of dimming is limited.

  In the control example of FIG. 16, since the current rest period is provided with respect to FIG. 15, the dimming range is widened. In the control examples of FIGS. 15 and 16, since the current is linearly changed (decreased), high performance is required in terms of the resolution and processing speed of the D / A converter 31 in FIG. Since the current is changed stepwise in the control example of FIG. 17, the configuration of the control circuit is simplified compared to the control examples of FIGS. 15 and 16, which is advantageous in terms of cost.

  In any of the embodiments, the magnitude of the forward current in the second period T2 is controlled, but the length of the second period T2 is not fixed, and the time of the second period T2 is changed. Thus, the effective current value may be substantially controlled. By doing so, the dimming range is widened, and smooth light control can be performed. When the entire period T becomes longer due to the change in the second period T2, the frequency decreases. However, the frequency may be changed within a range where the flicker is not perceived. For example, the flashing frequency based on the entire period T may be controlled with about 100 Hz as the lower limit.

  Further, regarding the forward current If1 in the first period T1, the difficulty of color shift varies depending on the type of LED, and therefore it may be set according to the characteristics of the LED. The design value of the first forward current If1 may be selected in a range of ± 10% to ± 20% with respect to the rated value of the LED.

  In the dimming control, the control of the magnitude of the second forward current If2 in the second period T2 or the control of the length of the second period is exemplified. The time period T1 and / or the value of the first forward current If1 may also be changed. The control in the first period T1 may be performed at a small rate of about 3% to 20% with respect to the control in the second period T2 so that the color shift is not noticeable.

(Embodiment 6)
Another specific embodiment of the present invention is shown in FIG. This embodiment is another specific example of the lighting circuit. In each of the above-described embodiments, the circuit has a boost function (a boost chopper circuit or a flyback converter circuit) assuming that the total forward voltage (n × Vf) of the LED load 2 is higher than the power supply voltage. When the total forward voltage (n × Vf) of the LED load 2 is a load lower than the power supply, a step-down chopper circuit may be used as shown in FIG. When the switching element S7 is turned on / off at a high frequency, the DC voltage obtained by stepping down the DC power supply 1a is charged in the capacitor C5. The control of the switching element S7 is basically the same as in each of the above-described embodiments, and the feedback control exemplified in FIG. 8 may be used.

(Embodiment 7)
FIG. 19 is a configuration example of the LED load 2. In each of the above-described embodiments, an n-series configuration as illustrated in FIG. 19A is illustrated, but a series-parallel circuit as illustrated in FIGS. 19B and 19C may be used. The LED load 2 is not limited with respect to the circuit configuration, the number of elements, and the like, and good dimming control can be performed in any case.

(Embodiment 8)
FIG. 20 is a schematic configuration diagram of a vehicle lighting device according to an eighth embodiment of the present invention. In the figure, 50 is a headlamp, 51 is an optical unit, 52 is a heat sink, 53 is a light source unit fixing jig, 54 is an output line, 55 is a power supply device, and 56 is an input line. The power supply device 55 houses a lighting circuit. The LED module 30 disposed behind the optical unit 51 includes the LED load 2 and is connected to the power supply device 55 via the output line 54. A DC power source such as a battery and the power supply device 55 are connected by an input line 56.

  The LED dimming lighting device of the present invention is particularly suitable for a vehicle lighting device. In addition to the headlamp as described above, a vehicle interior lighting device such as a room lamp, a tail lamp, a vehicle width lamp, and a brake lamp are used. Although it is used for such an exterior light illuminating device, it may be used for a general-purpose lighting fixture other than for a vehicle.

It is a wave form diagram which shows the basic operation | movement of this invention. It is a circuit diagram which shows the basic composition 1 of this invention. It is a wave form diagram which shows the circuit operation | movement of FIG. It is a circuit diagram which shows the basic composition 2 of this invention. FIG. 5 is a waveform diagram showing the circuit operation of FIG. 4. It is a circuit diagram which shows the whole structure of Embodiment 1 of this invention. It is a circuit diagram which shows the principal part structure of Embodiment 1 of this invention. It is a circuit diagram which shows the structure of Embodiment 2 of this invention. It is a wave form diagram which shows the circuit operation | movement of FIG. It is a circuit diagram which shows the structure of Embodiment 3 of this invention. It is a wave form diagram which shows the circuit operation | movement of FIG. It is a circuit diagram which shows the principal part structure of the modification of Embodiment 3 of this invention. It is a circuit diagram which shows schematic structure of Embodiment 4 of this invention. It is a circuit diagram which shows the detailed structure of Embodiment 4 of this invention. It is an operation | movement waveform diagram of Embodiment 5 of this invention. It is an operation | movement waveform diagram of the modification of Embodiment 5 of this invention. It is an operation | movement waveform diagram of the other modification of Embodiment 5 of this invention. It is a circuit diagram which shows the principal part structure of Embodiment 6 of this invention. It is a circuit diagram which shows the structural example of the LED load of Embodiment 7 of this invention. It is a schematic block diagram of the illuminating device for vehicles of Embodiment 8 of this invention. It is a circuit diagram which shows the structure of a prior art example. It is a wave form diagram which shows operation | movement of a prior art example.

Explanation of symbols

1a DC power supply 2 LED load 3a lighting circuit 4 dimming signal section 5 lighting circuit

Claims (4)

An LED load consisting of one or more LEDs;
A dimming signal unit for outputting a dimming signal for adjusting the light output of the LED load;
A lighting circuit that receives a dimming signal from the dimming signal unit and alternately supplies a first current and a second current from a power source to the LED load ;
The first current is a current near a rating at which the LED load emits a predetermined color, and the second current is a variable current upon receiving a dimming signal from the dimming signal unit ,
The LED has an LED element and a phosphor attached to the LED element,
The lighting circuit includes a first lighting circuit that intermittently outputs a current and a second lighting circuit that constantly outputs a constant current whose magnitude is controlled by receiving a dimming signal from the dimming signal unit. Then, the intermittent current supplied from the first lighting circuit and the constant current supplied from the second lighting circuit are steadily superimposed on each other, and the first current and the second current are superimposed on the LED load. LED dimming lighting device characterized by alternately supplying the current of . The first lighting circuit is a circuit that intermittently supplies current from the first DC power source to the LED load via a switching element that is intermittently turned on with a current limiting resistor, and the second lighting circuit is A circuit that supplies a dimming signal from the dimming signal unit to the LED load via a DC-DC converter circuit from a second DC power source and supplies a constant current of which magnitude is controlled, and the DC-DC the output current of the converter circuit, L ED dimming lighting device according to claim 1 you, characterized in that is variable receives the dimming signals from the dimming signal unit. Vehicle lighting device comprising a lighting equipment for L ED dimming according to claim 1 or claim 2. Luminaire comprising a lighting equipment for L ED dimming according to claim 1 or claim 2.

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