JP2016076315A - Light emission element driving device, light emission device and vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emission element driving device that can perform dimming control of light emission elements with high precision at a low cost without limiting setting of the series-connection number of the light emission elements to a narrow range.SOLUTION: A light emission driving device 10 has an output voltage generator 1H, 1L, 2H, 2L, 3, 4 for generating an output voltage Vo from an input voltage Vi so that output current Io flowing in a light emission element Z1 is coincident with a target value during an ON-period of a dimming signal S1, and stopping the generation operation of the output voltage Vo during an OFF-period of the dimming signal S1, an output capacitor C1 for smoothing the output voltage Vo and supplying the output voltage Vo to the light emission element Z1, an output voltage discharging part 5 for making the output capacitor C1 discharge from a time at which the dimming signal S1 is switched from the ON-period to the OFF-period until a set time elapses, and a time adjusting part 6 for adjusting the set time.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light emitting element driving device that drives a light emitting element, and a light emitting device and a vehicle using the same.

  FIG. 9 is a diagram illustrating a conventional example of a light emitting device. The light emitting device of this conventional example includes at least one light emitting element (light emitting diode in FIG. 9) Z1, a light emitting element driving IC (integrated circuit) 100 for driving the light emitting element Z1, and a light emitting element driving IC 100 to the light emitting element Z1. And a P-channel MOS [metal oxide semiconductor] field effect transistor P1 inserted in the power supply path.

  The light emitting element driving IC 100 generates an output voltage Vo from the input voltage Vi and supplies the output voltage Vo to the light emitting element Z1, and the transistor P1 is turned on based on a PWM [pulse width modulation] dimming signal S1. An output current control unit 102 that performs duty control (luminance control of the light emitting element Z1) of the output current Io flowing through the light emitting element Z1 by performing on / off control is a semiconductor integrated circuit device.

JP 2013-157238 A

  Certainly, with the light emitting device of the conventional example, it is possible to control the luminance of the light emitting element Z1 based on the PWM dimming signal S1. However, the light emitting device of the above conventional example has a problem of high cost because it requires the dimming control transistor P1.

  Therefore, Patent Document 1 proposes a light-emitting element driving device that can perform dimming control of a light-emitting element at a low cost by including an output voltage discharging unit that discharges an output capacitor during an off period of a dimming signal. Has been.

  Note that Patent Document 1 proposes a configuration in which the output voltage discharging unit discharges the output capacitor until the output voltage matches the discharge lower limit voltage higher than the ground voltage during the off period of the dimming signal (for example, Patents). (Refer FIG. 7 and FIG. 8 of the literature 1.) With this configuration, the light emitting element is turned off without delay during the off period of the dimming signal, and the light emitting element is turned on without delay during the on period of the dimming signal, that is, highly accurate dimming is possible. As a specific example of the configuration, a configuration example including a variable voltage source that outputs a discharge lower limit voltage and a comparator that compares the output voltage and the discharge lower limit voltage is given.

  However, in this configuration example, the light control accuracy cannot be increased unless the discharge lower limit voltage is increased as the series number of light emitting elements increases. Therefore, in order to set the number of light emitting elements in series in a wide range, a variable voltage source having a wide variable range is required, which leads to an increase in cost.

  In view of the above situation, the present invention is a light emitting element driving device capable of performing dimming control of a light emitting element with high accuracy at low cost without limiting the setting of the number of series of light emitting elements to a narrow range, and It aims at providing the light-emitting device and vehicle using this.

  In order to achieve the above object, a light emitting element driving device according to the present invention generates an output voltage from an input voltage so that an output current flowing through the light emitting element coincides with a target value during an on period of a dimming signal, An output voltage generation unit that stops the generation operation of the output voltage during the off period of the dimming signal, an output capacitor that smoothes the output voltage and supplies the output voltage to the light emitting element, and the dimming signal from the on period to the off period The output voltage discharging unit that discharges the output capacitor until the set time elapses after switching to the time, and the time adjusting unit that adjusts the set time (first configuration).

  In the light emitting element driving apparatus having the first configuration, the output voltage generation unit is connected in series between the application terminal of the input voltage and a ground terminal, and a connection node of the output voltage generation unit via the coil. An upper transistor and a lower transistor connected to a capacitor; an upper driver and a lower driver that generate control signals for the upper transistor and the lower transistor; an amplifier that generates a feedback voltage according to the output current; A control unit that drives the upper driver and the lower driver to turn on / off the upper transistor and the lower transistor in accordance with the feedback voltage during an on period of the dimming signal (first operation) 2).

  Further, in the light emitting element driving device having the second configuration, the output voltage discharging unit conducts / cuts off between the application terminal of the output voltage and the ground terminal based on the output signal of the time adjusting unit. A configuration including a transistor for use (third configuration) is preferable.

  Further, in the light emitting element driving apparatus having the third configuration, the discharge transistor is always turned off during the on period of the dimming signal, and the output signal of the time adjusting unit is turned off during the off period of the dimming signal. It is preferable to adopt a configuration (fourth configuration) that is turned on / off based on the above.

  Further, in the light emitting element driving apparatus having the fourth configuration, the control unit may be configured to always turn off the upper transistor and the lower transistor so that both the upper transistor and the lower transistor are always turned off during the off period of the dimming signal. A configuration for driving the lower driver (fifth configuration) is preferable.

  In the light emitting element driving device having any one of the first to fifth configurations, the output voltage generation unit, the output voltage discharge unit, and the time adjustment unit are all integrated in the same semiconductor device. (6th configuration).

  A light-emitting device according to the present invention includes a light-emitting element driving device having any one of the first to sixth configurations and at least one light-emitting element driven by the light-emitting element driving device (seventh). It is said that.

  In the light emitting device having the seventh configuration, the light emitting element may be a light emitting diode or an organic EL element (eighth configuration).

  Further, the light emitting device having the eighth configuration may be configured to be used as a vehicle lamp (9th configuration).

  The light emitting device having the ninth configuration may be configured to be mounted on the vehicle as a headlight module, a turn lamp module, or a rear lamp module (tenth configuration).

  In addition, the vehicle according to the present invention has a light emitting device having the ninth or tenth structure (an eleventh structure).

  Further, in the vehicle having the eleventh configuration, the light emitting device is configured to be used as at least one of a headlight, a light source for running day and night, a tail lamp, a stop lamp, and a turn lamp (a twelfth configuration). Good.

  According to the present invention, a light emitting element driving apparatus capable of performing dimming control of a light emitting element with high accuracy at a low cost without limiting the setting of the number of series of light emitting elements to a narrow range, and the same are used. A light emitting device and a vehicle can be provided.

The figure which shows the example of 1 structure of a light-emitting device Time chart for explaining an operation example of the light emitting element driving device Waveform diagram showing falling behavior of output current Io External view of the vehicle equipped with the light emitting device (front) External view of vehicle equipped with light emitting device (back) External view of LED headlight module External view of LED turn lamp module External view of LED rear lamp module The figure which shows one prior art example of a light-emitting device The figure which shows the other conventional example of a light-emitting device

  FIG. 1 is a diagram illustrating a configuration example of a light emitting device. The light emitting device 10 includes a light emitting element driving device having a light emitting element driving IC 11A, a coil L1, an output capacitor C1, a sense resistor Rs, and a capacitor C2. In addition, the light emitting device 10 includes at least one light emitting element (light emitting diode) Z1 that is a driving target of the light emitting element driving device.

  The light emitting element driving IC 11A includes N-channel MOS field effect transistors 1H and 1L (hereinafter referred to as an upper transistor 1H and a lower transistor 1L), an upper driver 2H and a lower driver 2L, a diode D1, and a controller 3 A semiconductor integrated circuit device (so-called LED driver IC) in which an amplifier 4, an N-channel MOS field effect transistor 5 (hereinafter referred to as transistor 5), and a time adjustment unit 6 are integrated. The light emitting element driving device 11A has external terminals T1 to T8 in order to establish an electrical connection with the outside.

  Outside the light emitting element driving IC 11A, the external terminal T1 is connected to the application terminal of the input voltage Vi. The external terminal T2 is connected to the first end of the coil L1. The second end of the coil L1 (the end to which the output voltage Vo is applied) is connected to the first end of the sense resistor Rs. The second end of the sense resistor Rs is connected to the first end (anode) of the light emitting element Z1. The second end (cathode) of the light emitting element Z1 is connected to the ground end. The first end of the output capacitor C1 is connected to the second end of the coil L1. The second terminal of the output capacitor C1 is connected to the ground terminal. The external terminal T3 is connected to the ground terminal. The external terminal T4 is connected to the first end of the coil L1 via the capacitor C2. The external terminal T5 is connected to the first end of the sense resistor Rs. The external terminal T6 is connected to the second end of the sense resistor Rs. The external terminal T7 is connected to the application end of the PWM dimming signal S1. The external terminal T8 is connected to the application end of the time adjustment signal S2.

  Inside the light emitting element driving IC 11A, the drain of the upper transistor 1H is connected to the external terminal T1. The source of the upper transistor 1H is connected to the external terminal T2. The gate of the upper transistor 1H is connected to the output terminal of the upper driver 2H. The drain of the lower transistor 1L is connected to the external terminal T2. The source of the lower transistor 1L is connected to the external terminal T3. The gate of the lower transistor 1L is connected to the output terminal of the lower driver 2L. That is, the upper transistor 1H and the lower transistor 1L are connected in series between the application terminal of the input voltage Vi and the ground terminal, and a connection node (application terminal of the switch voltage Vsw) is output via the coil L1. It is connected to the capacitor C1.

  The upper driver 2H generates a control signal GH for the upper transistor 1H based on an instruction from the control unit 3. The upper transistor 1H is turned on when the control signal GH is at a high level, and turned off when the control signal GH is at a low level. The lower driver 2L generates a control signal GL for the lower transistor 1L based on an instruction from the control unit 3. The lower transistor 1L is turned on when the control signal GL is at a high level, and turned off when the control signal GL is at a low level.

  The diode D1 and the capacitor C2 externally attached to the light emitting element driving IC 11A constitute a bootstrap circuit. The bootstrap circuit generates a boost voltage Vbst. The anode of the diode D1 is connected to the application terminal of the constant voltage Vreg. The cathode of the diode D1 is connected to the external terminal T4.

  The first power supply terminal of the upper driver 2H and the first power supply terminal of the control unit 3 are connected to the external terminal T4 (application terminal of the boost voltage Vbst). The second power supply terminal of the upper driver 2H is connected to the external terminal T2 (application terminal for the switch voltage Vsw). Therefore, the high level of the control signal GH applied to the gate of the upper transistor 1H is the boost voltage Vbst, and the low level of the control signal GH is the switch voltage Vsw.

  The first power supply terminal of the lower driver 2L is connected to the application terminal for the constant voltage Vreg. The second power supply terminal of the lower driver 2L is connected to the external terminal T3 (application terminal for the ground voltage GND). Accordingly, the high level of the control signal GL applied to the gate of the lower transistor 1L becomes the constant voltage Vreg, and the low level of the control signal GL becomes the ground voltage GND.

  The operation of the bootstrap circuit having the above configuration will be described. When the upper transistor 1H is turned off and the lower transistor 1L is turned on so that the switch voltage Vsw is at the low level (GND), the current that flows from the application terminal of the constant voltage Vreg to the capacitor C2 through the diode D1. As a result, the capacitor C2 is charged. At this time, the boost voltage Vbst is substantially a constant voltage Vreg (more precisely, a value obtained by subtracting the forward drop voltage Vf of the diode D1 from the constant voltage Vreg (Vreg−Vf)).

  On the other hand, when the upper transistor 1H is turned on and the lower transistor 1L is turned off while the capacitor C2 is charged, the switch voltage Vsw is raised from the low level (GND) to the high level (Vi). The boost voltage Vbst is raised to a value (Vi + Vreg) that is higher than the high level (Vi) of the switch voltage Vsw by the charge voltage (approximately Vreg) of the capacitor C2. By applying such a boost voltage Vbst to the first power supply terminal of the upper driver 2H, the upper transistor 1H can be reliably turned on / off.

  The control unit 3 switches the upper driver 2H and the lower driver 2L so as to turn on / off the upper transistor 1H and the lower transistor 1L according to the feedback voltage Vfb during the ON period (high level period) of the PWM dimming signal S1. To drive. On the other hand, the control unit 3 drives the upper driver 2H and the lower driver 2L so as to stop the generation operation of the output voltage Vo during the OFF period (low level period) of the PWM dimming signal S1.

  The amplifier 4 amplifies the voltage across the sense resistor Rs applied between the non-inverting input terminal (+) and the inverting input terminal (−) to generate a feedback voltage Vfb. Therefore, the feedback voltage Vfb is a voltage signal that increases or decreases according to the output current Io flowing through the sense resistor Rs.

  Note that the upper transistor 1H, the lower transistor 1L, the upper driver 2H, the lower driver 2L, the control unit 3, and the amplifier 4 are configured so that the output current Io that flows through the light emitting element Z1 during the ON period of the PWM dimming signal S1. An output voltage Vo is generated from the input voltage Vi so as to coincide with the target value, and an output voltage generation unit that stops the generation operation of the output voltage Vo is formed during the OFF period of the PWM dimming signal S1.

  In the light emitting element driving IC 11A, the drain of the transistor 5 is connected to the external terminal T5. The source of the transistor 5 is connected to the ground terminal. The gate of the transistor 5 is connected to the output terminal of the time adjustment unit 6. That is, the transistor 5 functions as a discharging transistor that conducts / cuts off between the application terminal of the output voltage Vo and the ground terminal based on the control signal GD output from the time adjustment unit 6. The transistor 5 is turned on when the control signal GD is at a high level and conducts between the application terminal of the output voltage Vo and the ground terminal, and is turned off when the control signal GL is at a low level, and the application terminal of the output voltage Vo. And the grounding end.

  The time adjustment unit 6 generates a control signal GD based on the PWM dimming signal S1 and the time adjustment signal S2. The control signal GD is always at a low level during the high level period (on period Ton) of the PWM dimming signal S1, and during the low level period (off period Toff) of the PWM dimming signal S1, The high level is maintained until the set time elapses after the high level period is switched to the low level period, and thereafter, the low level is maintained. The set time varies based on the time adjustment signal S2. The internal configuration of the time adjustment unit 6 and the format of the time adjustment signal S2 are not particularly limited. For example, when the time adjustment unit 6 includes a storage unit that stores data related to the set time in a nonvolatile manner, the time adjustment signal S2 is What is necessary is just to use it as the rewriting signal for rewriting the data regarding setting time.

  FIG. 2 is a time chart for explaining an operation example of the light-emitting device 10 shown in FIG. 1. In order from the top, the PWM dimming signal S1, the control signals GH and GL, the switch voltage Vsw, the output voltage Vo, and the control signal. GD and output current Io are depicted.

  The PWM dimming signal S1 is a pulse width modulation signal whose on-duty (ratio of the on period Ton in the period T) is varied according to the luminance of the light emitting element Z1. When increasing the luminance of the light emitting element Z1, the on-duty of the PWM dimming signal S1 is set to a large value. Conversely, when decreasing the luminance of the light emitting element Z1, the on-duty of the PWM dimming signal S1 is small. Set to a value.

  When the PWM dimming signal S1 rises to a high level at time t1, on / off control (control signal GH and GL generation operation) of the upper transistor 1H and the lower transistor 1L is started by the control unit 3, A rectangular wave switch voltage Vsw is generated at the external terminal T2. The switch voltage Vsw is supplied to the light emitting element Z1 as a smoothed output voltage Vo through the coil L1 and the output capacitor C1.

  In the ON period Ton (time t1 to t3) of the PWM dimming signal S1, the upper transistor 1H and the lower transistor 1L are complementary so that the feedback voltage Vfb (and thus the output current Io) matches a predetermined target value. On / off exclusively. If the output current Io flowing through the light emitting element Z1 is constant, the output voltage Vo applied to the light emitting element Z1 is also constant, so that the light emitting element Z1 is lit with a constant luminance.

  Note that the term “complementary (exclusive)” used above refers to the case where the on / off state of the upper transistor 1H and the lower transistor 1L is completely reversed, as well as from the viewpoint of preventing through current. This includes the case where a simultaneous off period of the transistor 1H and the lower transistor 1L is provided.

  In the on period Ton (time t1 to t3) of the PWM dimming signal S1, the control signal GD is always at a low level, and the transistor 5 is always off.

  When the PWM dimming signal S1 falls to the low level at time t3, the generation operation of the output voltage Vo is stopped. In particular, in the dimming method shown in FIG. 2, the control signals GH and GL are both set to the low level during the OFF period Toff (time t3 to t5) of the PWM dimming signal S1, and the upper transistor 1H and the lower transistor 1L is turned off. As a result, the external terminal T2 (application end of the switch voltage Vsw) is in a high impedance state (Hi-Z).

  In the OFF period Toff (time t3 to t5) of the PWM dimming signal S1, the timing at which the set time Δt elapses from the timing (time t3) when the control signal GD is switched from the ON period Ton to the OFF period Toff of the PWM dimming signal S1. It becomes a high level until (time t4), and thereafter becomes a low level. Therefore, the transistor 5 is turned on during a period (time t3 to t4) from the timing when the PWM dimming signal S1 is switched from the on period Ton to the off period Toff to the timing when the set time Δt elapses. As a result, during the period (time t3 to t4) from the timing when the PWM dimming signal S1 switches from the on period Ton to the off period Toff to the timing when the set time Δt elapses (time t3 to t4), the first end (output voltage) Since the application end of Vo is short-circuited to the ground end via the transistor 5, the charge of the output capacitor C1 is rapidly discharged, and the output voltage Vo is lowered to the lower limit voltage Vmin at time t4.

  Here, the set time Δt is adjusted using the time adjustment signal S2 so that the lower limit voltage Vmin is less than the forward voltage of the light emitting element Z1. Thereby, the output current flowing through the light emitting element Z1 by time t4 becomes 0A, and the light emitting element Z1 is turned off without delay.

  By repeating the on period Ton and the off period Toff, the light emitting element Z1 is repeatedly turned on and off, so that the apparent luminance of the light emitting element Z1 (in the period T) according to the on-duty of the PWM dimming signal S1. It becomes possible to variably control (average luminance). According to this dimming method, the external transistor P1 for dimming (see FIG. 9) is not required, so that the cost can be reduced as compared with the conventional dimming method.

  Further, since the output voltage Vo does not fall down to 0V in the OFF period Toff of the PWM dimming signal S1, the output current Io and the output voltage Vo reach their target values in the next ON period Ton of the PWM dimming signal S1. Rise time (see times t1 to t2 and times t5 to t6) is shortened, and the light emitting element Z1 is lit without delay. Further, as described above, during the high level period (time t3 to t4 and time t7 to t8) of the control signal GD, the first end (the application end of the output voltage Vo) of the output capacitor C1 is connected via the transistor 5. Since it is short-circuited with the ground terminal, the charge of the output capacitor C1 is rapidly discharged, and the light emitting element Z1 is turned off without delay.

  This makes it possible to perform dimming control of the light emitting element Z1 with high accuracy. Further, in the light emitting device that does not have means for discharging the charge of the output capacitor C1 as in the conventional light emitting device shown in FIG. 10, the falling behavior of the output current Io becomes as shown by the broken line Y2 shown in FIG. It takes time until the light emitting element Z1 is turned off after the optical signal S1 is turned off. For this reason, the light control rate of the light emitting element Z1 cannot be reduced. On the other hand, in the light emitting device 10, the falling behavior of the output current Io becomes as indicated by the solid line Y1 shown in FIG. 3, and the light emitting element Z1 is turned off after the PWM dimming signal S1 is turned off. It does not take time (the light is extinguished in an elapsed period of time equal to or less than the set time Δt after the PWM dimming signal S1 enters the off period Toff). For this reason, the light control rate of the light emitting element Z1 can be narrowed down. In the light emitting device 10 shown in FIG. 1, as an example, when the frequency of the PWM dimming signal S1 (reciprocal of the period T) is 200 Hz, the dimming rate of the light emitting element Z1 can be reduced to 0.5%.

  In the light emitting device 10, the time adjustment unit 6 is configured to turn on the transistor 5 on the basis of the time adjustment signal S <b> 2 and discharge the charge of the output capacitor C <b> 1. Even in this case, a variable voltage source with a wide variable range is not required. Therefore, the light emitting device 10 shown in FIG. 1 does not limit the setting of the series number of the light emitting elements Z1 to a narrow range.

<Application>
For example, as shown in FIGS. 4 and 5, the light emitting device 10 includes a headlight (including a high beam / low beam / small lamp / fog lamp, etc.) X11, a light source X12 for day / night driving (DRL), a tail lamp (as shown in FIG. 4 and FIG. 5). X13, stop lamp X14, turn lamp X15, and the like can be suitably used.

  The light emitting element driving IC 11A is a module (LED headlight module Y10 in FIG. 6, LED in FIG. 7) together with external components (output capacitor C1, capacitor C2, coil L1, sense resistor Rs) and the light emitting element Z1 to be driven. Turn lamp module Y20, LED rear lamp module Y30 in FIG. 8, etc.), external components (output capacitor C1, capacitor C2, coil L1, sense resistor Rs) and drive target It may be provided as a single IC (light emitting element driving IC 11A) that is a semi-finished product independently of the light emitting element Z1.

<Other variations>
In the above embodiment, the configuration using a light emitting diode as a light emitting element has been described as an example. However, the configuration of the present invention is not limited to this, and for example, an organic EL [ It is also possible to use an electro-luminescence element.

  Various technical features disclosed in the present specification can be variously modified within the scope of the technical creation in addition to the above-described embodiment. For example, mutual replacement of a bipolar transistor and a MOS field effect transistor and logic level inversion of various signals are arbitrary. That is, the above-described embodiment is an example in all respects and should not be considered as limiting, and the technical scope of the present invention is not the description of the above-described embodiment, but the claims. It should be understood that all modifications that come within the meaning and range of equivalents of the claims are included.

1H N-channel MOS field effect transistor (upper transistor)
1L N-channel MOS field effect transistor (lower transistor)
2H Upper side driver 2L Lower side driver 3 Control unit 4 Amplifier 5 N channel type MOS field effect transistor (discharge transistor)
10 Light Emitting Device 11A Light Emitting Element Drive IC
C1 Output capacitor C2 Capacitor D1 Diode L1 Coil Rs Sense resistor T1 to T8 External terminal X10 Vehicle X11 Headlight X12 Light source for day and night driving (DRL) X13 Tail lamp X14 Stop lamp X15 Turn lamp Y10 LED headlight module Y20 LED turn lamp module Y30 LED rear lamp module Z1 Light emitting element (light emitting diode)

Claims (12)

An output voltage is generated from the input voltage so that the output current flowing through the light emitting element matches the target value during the ON period of the dimming signal, and the output voltage generation operation is stopped during the OFF period of the dimming signal A voltage generator;
An output capacitor for smoothing the output voltage and supplying the light emitting element;
An output voltage discharging unit that discharges the output capacitor until a set time elapses after the dimming signal is switched from an on period to an off period;
A time adjustment unit for adjusting the set time;
A light-emitting element driving device comprising: The output voltage generator is
An upper transistor and a lower transistor that are connected in series between the application terminal of the input voltage and the ground terminal, and whose connection nodes are connected to the output capacitor via a coil;
An upper driver and a lower driver for generating respective control signals of the upper transistor and the lower transistor;
An amplifier that generates a feedback voltage according to the output current;
A controller that drives the upper driver and the lower driver to turn on / off the upper transistor and the lower transistor according to the feedback voltage during an on period of the dimming signal;
The light-emitting element driving device according to claim 1, comprising:   The said output voltage discharge part contains the transistor for discharge which conducts / cuts off between the application end of the said output voltage, and the earthing | grounding end based on the output signal of the said time adjustment part. Light emitting element driving device.   The discharge transistor is always turned off during an on period of the dimming signal, and is turned on / off based on an output signal of the time adjustment unit during the off period of the dimming signal. 4. The light emitting element driving device according to 3.   The control unit drives the upper driver and the lower driver so that both the upper transistor and the lower transistor are always turned off during the off period of the dimming signal. The light emitting element drive device of description.   6. The output voltage generation unit, the output voltage discharge unit, and the time adjustment unit are all integrated in the same semiconductor device. Light emitting element driving device. The light emitting element driving device according to any one of claims 1 to 6,
At least one light emitting element driven by the light emitting element driving device;
A light emitting device comprising:   The light emitting device according to claim 7, wherein the light emitting element is a light emitting diode or an organic EL element.   The light emitting device according to claim 8, wherein the light emitting device is used as an in-vehicle lamp.   The light-emitting device according to claim 9, wherein the light-emitting device is attached to a vehicle as a headlight module, a turn lamp module, or a rear lamp module.   A vehicle comprising the light emitting device according to claim 9.   The vehicle according to claim 11, wherein the light emitting device is used as at least one of a headlight, a light source for driving day and night, a tail lamp, a stop lamp, and a turn lamp.

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