JP2020098671A - Lighting fixture for vehicle - Google Patents

Abstract

To provide a lighting fixture for vehicle capable of aiming for longer life while restraining power consumption, and capable of facilitating flashing or dimming control.SOLUTION: A lighting fixture for vehicle is connected with a DC power supply 61. The lighting fixture for vehicle includes a first light source 1, a second light source 2, a pseudo load 3 connected in parallel with the second light source 2, a constant current power supply 5 for supplying a first current I1 to the first light source 1, a current mirror circuit 7 connecting the first light source 1 and the second light source 2 in parallel, and equalizing the magnitude of a second current I2, supplied from the DC power supply 61 to any one of the second light source 2 and the pseudo load 3, and the magnitude of the first current I1, and a PWM control circuit 8 connected between the constant current power supply 5 and the DC power supply 61, and controlling lighting of the first light source 1 and the second light source 2. The PWM control circuit 8 controls the ON time of the pseudo load 3 according to the lighting period of the second light source 2.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicle lamp.

BACKGROUND ART Among vehicle lamps, those using a semiconductor-type light source as a light source have been conventionally proposed (for example, refer to Patent Documents 1 to 3). The conventional semiconductor-type light sources described in Patent Documents 1 to 3 are used as a plurality of LED chips mounted on a substrate covered with a sealing member such as resin.

JP, 2004-039290, A JP, 2006-261160, A JP, 2017-069161, A

However, in the conventional technique as described in Patent Document 1, the current mirror circuit requires a power supply device that supplies a constant voltage power supply, and since it is resistance drive, in order to increase the reference current of the current mirror circuit, Power consumption also increases, and heat generation increases with the increase in power consumption. Further, in the conventional technique as described in Patent Document 2, since the light sources are connected in series, an overcurrent generated by controlling on/off of some of the light sources flows into some of the other light sources to cause circuit elements. May impose a burden on the circuit element and lead to a short life or damage to the circuit element. Further, in the conventional technique described in Patent Document 3, it is not possible to cope with the temperature change of the light source, and it is not possible to individually control the blinking or dimming of the light source.

The present disclosure has been made in view of such a situation, and aims to extend the life of the power supply while suppressing power consumption and facilitate blinking or dimming control.

A vehicular lamp according to one aspect of the present disclosure is a vehicular lamp that is connected to a DC power supply, and includes a first light source, a second light source, a pseudo load connected in parallel with the second light source, and A constant current power source for supplying a first current to a first light source, the first light source and the second light source are connected in parallel, and the DC power source is one of the second light source and the dummy load. It is connected between a current mirror circuit that makes the magnitude of the second current supplied to one of the two equal to the magnitude of the first current, the constant current power source, and the DC power source, and the first light source and the first light source are connected. A PWM control circuit for controlling lighting of two light sources, wherein the PWM control circuit controls an ON time of the pseudo load according to a lighting cycle of the second light source.

Further, in the vehicle lighting device according to one aspect of the present disclosure, a bypass circuit that is connected in parallel to the first light source and diverts the first current is further provided, and the bypass circuit includes a first switching element, A resistive load connected in series with the first switching element, wherein the current mirror circuit has a second switching element having a collector connected in series with the resistive load and an emitter connected to chassis ground; A third switching element connected in series with the pseudo load and having an emitter connected to the chassis ground, the collector and the base of the second switching element being connected, and the second switching element and the second switching element. The bases of the three switching elements are connected to each other, and the PWM control circuit controls the first switching element to be in the ON state when supplying the second current to the second light source. preferable.

Further, in the vehicular lamp according to one aspect of the present disclosure, the constant current power supply has a magnitude of the first current that is equal to a magnitude of a current according to lighting of one of the first light source and the second light source. Is preferably controlled.

Further, in the vehicular lamp according to one aspect of the present disclosure, it is preferable that a plurality of the second light sources are provided in parallel.

According to one aspect of the present disclosure, it is possible to achieve a long life and facilitate blinking or dimming control while suppressing power consumption.

1 is a circuit configuration diagram of a vehicle lamp according to an embodiment to which the present disclosure is applied.

Hereinafter, an embodiment of a vehicular lamp to which the present disclosure is applied will be described in detail with reference to the drawings. The present disclosure is not limited to this embodiment.

FIG. 1 is a circuit configuration diagram of a vehicle lamp according to an embodiment to which the present disclosure is applied. The vehicular lamp includes a first light source 1, second light sources 21 to 23, pseudo loads 31 to 33, a constant current power source 5, a current mirror circuit 7, a PWM control circuit 8 and the like, and is connected to the DC power sources 61 and 62. As a result, DC power is supplied from the DC power supplies 61 and 62, and the first light source 1 or the second light sources 21 to 23 can be turned on. In addition, when any one of the second light sources 21 to 23 is not specified, it is referred to as a second light source 2. Moreover, when any one of the pseudo loads 31 to 33 is not specified, it is referred to as a pseudo load 3. However, the second light source 2 and the pseudo load 3 include the second light source 21 and the pseudo load 31 connected in parallel with the second light source 21, the second light source 22 and the pseudo load 32 connected in parallel with the second light source 22, and It means any one combination of the second light source 23 and the pseudo load 33 connected in parallel with the second light source 23. The vehicular lamp has, for example, a function such as a rear combination lamp.

The constant current power supply 5 is supplied with DC power from the DC power supply 62 and supplies the first current I1 to the first light source 1. In the first light source 1, a plurality of semiconductor light emitting elements D11 are connected in series, and a capacitor C11 is connected in parallel to each of the plurality of semiconductor light emitting elements D11. The semiconductor light emitting element D11 is a self-luminous semiconductor light source such as an OLED (organic light emitting diode) using an LED or an OEL (organic EL). When the constant current power supply 5 has a PWM control function or a current variable function, the constant current power supply 5 can control the magnitude of the first current I1.

A bypass circuit 9 is connected in parallel to the first light source 1. The bypass circuit 9 includes a first switching element Q1 and a resistive load R1 connected in series with the first switching element Q1 and diverts the first current I1 from the first light source 1. The first switching element Q1 is composed of, for example, a P-channel MOSFET, the source is connected to the constant current power source 5, the drain is connected to the resistive load R1, and the capacitor C1 is connected between the gate and the drain. There is. The first switching element Q1 is controlled by the PWM control circuit 8. When the first switching element Q1 is controlled to be in the ON state by the PWM control circuit 8, the first current I1 passes through the bypass circuit 9, so that the first light source 1 is turned off. When the PWM control circuit 8 controls the first switching element Q1 to be in the OFF state, the first current I1 does not pass through the bypass circuit 9, so the first light source 1 is turned on.

On the other hand, each of the second light sources 21 to 23 has one connected to the plus terminal of the DC power supply 61 and the other connected to the current mirror circuit 7. The DC power supply 61 supplies the second current I2 to one of the second light sources 21 to 23 and the pseudo loads 31 to 33, and the diode D5 is provided in parallel. In the second light source 21, a plurality of semiconductor light emitting elements D21 are connected in series, and a capacitor C21 is connected in parallel to each of the plurality of semiconductor light emitting elements D21. The semiconductor light emitting element D21 is configured similarly to the semiconductor light emitting element D11, for example. The second light sources 22 and 23 have the same circuit configuration as the second light source 21. That is, the second light source 22 includes the semiconductor light emitting element D22 and the capacitor C22 connected in parallel with the semiconductor light emitting element D22. The second light source 23 includes a semiconductor light emitting element D23 and a capacitor C23 connected in parallel with the semiconductor light emitting element D23.

The DC power supplies 61 and 62 have a circuit configuration capable of supplying a DC current, such as a secondary battery or a DCDC converter, and are provided outside the vehicle lamp. Further, the DC power supply 61 is provided with a switch S1 capable of controlling whether or not to supply power to the vehicle lamp. When the switch S1 is turned on, the DC power supply 61 is turned on with respect to the vehicular lamp, and the second current I2 can be supplied to each of the second light sources 21-23. The DC power supply 62 is also provided with a switch S2 that functions similarly to the DC power supply 61. The switches S1 and S2 are composed of non-contact electronic relays such as solid state relays, and are controlled by the PWM control circuit 8.

Each of the pseudo loads 31 to 33 is connected in parallel with each of the second light sources 21 to 23. The pseudo load 31 includes a pseudo switching element Q31, a pseudo resistance R31 connected in series with the pseudo switching element Q31, and a pseudo capacitor C31, and diverts the second current I2 from the second light source 21. Is. The pseudo switching element Q31 is composed of, for example, a P-channel MOSFET, the source is connected to the positive terminal of the DC power supply 61, the drain is connected to the pseudo resistor R31, and the pseudo capacitor is provided between the gate and the drain. C31 is connected. The pseudo switching element Q31 is controlled by the PWM control circuit 8. When the pseudo switching element Q31 is turned on by the PWM control circuit 8, the second current I2 passes through the pseudo load 31 and the second light source 2 is turned off. When the pseudo switching element Q31 is controlled to be in the off state by the PWM control circuit 8, the second current I2 does not pass through the pseudo load 31, so that the second light source 2 is turned on. The pseudo loads 32 and 33 have the same circuit configuration as the pseudo load 31. That is, the pseudo load 32 includes a pseudo switching element Q32, a pseudo resistor R32, and a pseudo capacitor C32, and the pseudo switching element Q32 is controlled by the PWM control circuit 8. Further, the pseudo load 33 includes a pseudo switching element Q33, a pseudo resistor R33, and a pseudo capacitor C33, and the pseudo switching element Q33 is controlled by the PWM control circuit 8.

When any one of the pseudo resistors R31 to R33 is not specified, it is referred to as a pseudo resistor R3. When any one of the pseudo capacitors C31 to C33 is not specified, it is referred to as a pseudo capacitor C3. Moreover, when any one of the pseudo switching elements Q31 to Q33 is not specified, it is referred to as a pseudo switching element Q3. Moreover, when any one of the capacitors C21 to C23 is not specified, it is referred to as a capacitor C2. When any one of the semiconductor light emitting devices D21 to D23 is not specified, it is referred to as a semiconductor light emitting device D2. However, the pseudo resistor R3, the pseudo capacitor C3, and the pseudo switching element Q3 are the combination of the pseudo resistor R31, the pseudo capacitor C31, and the pseudo switching element Q31, the pseudo resistor R32, the pseudo capacitor C32, and the pseudo switching. This means any one of the combination of the element Q32 and the combination of the dummy resistor R33, the dummy capacitor C33, and the dummy switching element Q33. Similarly, the capacitor C2 and the semiconductor light emitting device D2 mean any one combination of the capacitor C21 and the semiconductor light emitting device D21, the capacitor C22 and the semiconductor light emitting device D22, and the capacitor C23 and the semiconductor light emitting device D23.

The current mirror circuit 7 is formed by connecting the first light source 1 and the second light source 2 in parallel, and the second current I2 supplied from the DC power source 61 to either the second light source 2 or the pseudo load 3. Is the same as the magnitude of the first current I1. Specifically, the current mirror circuit 7 includes a second switching element Q2 and third switching elements Q51 to Q53. In addition, when any one of the third switching elements Q51 to Q53 is not specified, it is referred to as a third switching element Q5. The second switching element Q2 is composed of an NPN transistor, the collector is connected in series with the resistive load R1, and the emitter is connected to the chassis ground GND. The third switching element Q5 is composed of an NPN transistor, the collector is connected in series with the pseudo load 3, and the emitter is connected to the chassis ground GND.

The current mirror circuit 7 has a collector and a base of the second switching element Q2 connected to each other. As shown in FIG. 1, the current mirror circuit 7 includes an NPN transistor between the collector and the base of the second switching element Q2. By providing the characteristic adjusting switching element Q4 described above, the characteristic difference between the second switching element Q2 and the third switching element Q5 can be compensated by the gain of the characteristic adjusting switching element Q4. Specifically, the characteristic adjustment switching element Q4 has a base connected to the resistive load R1, the cathode/cathode terminal of the semiconductor light emitting element D11 and the capacitor C11, a collector connected to the resistor R2, and an emitter connected to the second switching element Q2. It is connected to the base of the third switching element Q5. One of the resistors R2 is connected to the collector of the characteristic adjusting switching element Q4, and the other is connected to the positive terminal of the DC power supply 61. In addition, the current mirror circuit 7 is one in which the bases of the second switching element Q2 and the third switching element Q5 are connected to each other, and at least the temperature characteristics of the second switching element Q2 and the third switching element Q5, respectively. Are preferably in the same range. The bases of the third switching elements Q51 to Q53 are connected to each other, and the emitters thereof are both connected to the chassis ground GND. With such a circuit configuration, the current mirror circuit 7 makes the magnitude of the second current I2 the same as the magnitude of the first current I1 when the second switching element Q2 and the third switching element Q5 are turned on. In addition, in FIG. 1, a plurality of each of the second light sources 21 to 23 is provided in parallel.

The PWM control circuit 8 is connected between the constant current power source 5 and the DC power source 61 and controls the lighting of the first light source 1 and the second light source 2 based on the lighting signal. A diode D6 is provided at a part of the PWM control circuit 8 on the input side of the lighting signal. The lighting signal is realized by various signals such as a rectangular wave. Specifically, the PWM control circuit 8 controls the ON time of the pseudo load 3 according to the lighting cycle of the second light source 2. That is, the PWM control circuit 8 controls the on/off duty ratio of the pseudo switching element Q3 according to the lighting cycle of the second light source 2. Therefore, blinking control or dimming control of the second light source 2 is possible. Therefore, the brightness of the second light source 2 is determined by the ratio between the current value, which is the magnitude of the second current I2 flowing through the second light source 2, and the time during which the second current I2 flows. However, the constant of the pseudo resistor R3 of the pseudo load 3 is set so that the applied voltage of the pseudo load 3 <the maximum extinction voltage of the second light source 2. Further, it is possible to reduce noise generation by suppressing the on/off speed of the pseudo switching element Q3 and the voltage fluctuation of the pseudo load 3 as a whole.

Further, the PWM control circuit 8 controls the first switching element Q1 to be in the ON state when supplying the second current I2 to the second light source 2. That is, when the first switching element Q1 is in the ON state, the first current I1 does not flow in the first light source 1, and the first current I1 is for the characteristic adjustment in which the resistance load R1 and the base are connected to the resistance load R1. It flows to the switching element Q4. Therefore, if the first current I1 is large enough to turn on the second switching element Q2 and the pseudo switching element Q3 of the current mirror circuit 7, the DC power supply 61 is turned on, and the second light sources 21 to 21 are turned on. The second current I2 can be made to flow in each of 23 in the same magnitude as the first current I1. That is, the second light source 2 can be turned on without turning on the first light source 1.

In addition, when only the first light source 1 is turned on, the constant current power source 5 may be operated and the supply of the second current I2 from the DC power source 61 to the second light source 2 may be stopped. Specifically, the PWM control circuit 8 controls the first switching element Q1 to be in the OFF state, so that the first current I1 supplied from the constant current power source 5 flows to the first light source 1 instead of the bypass circuit 9. Therefore, the first light source 1 is turned on by the first current I1 flowing through the first light source 1, and the first current I1 is further transmitted through the characteristic adjusting switching element Q4 to the second switching element Q2 and the third switching element. It flows to the base of the element Q5. When the DC power supply 61 is turned on in such a circuit connection state, the current mirror circuit 7 causes the second current I2 to flow through the second light sources 21 to 23 in the same magnitude as the first current I1. That is, in order to turn on the second light source 2 while the first light source 1 is on, the DC power supply 61 may be controlled to be in the on state.

From the above description, it is not necessary to make the constant current power supply 5 as a custom product. Therefore, the standard constant-current power supply 5 may be used according to the maximum current of the second light source 2. Further, each of the second light sources 21 to 23 can individually perform dimming by PWM control. Further, when the first light source 1 is not used, by switching the output destination of the first current I1 supplied from the constant current power source 5 from the first light source 1 to the bypass circuit 9, the power consumption of the first light source 1 is not generated. The power consumption as a whole can be suppressed. In addition, if the constant current power source 5 has a circuit configuration capable of controlling the magnitude of the first current I1 such as the PWM control function, the magnitude of the current suitable for each of the first light source 1 and the second light source 2 is set. Since the magnitude of the one current I1 can be controlled, the power consumption as a whole can be suppressed, and further, the application of the second light source 2 can be expanded. For example, a lighting device such as a vehicle can be expanded not only to the function of a rear combination lamp or the like, but also to the function of a headlamp that requires more light.

From the above description, in the present embodiment, in the current mirror circuit 7, the magnitude of the second current I2 is the same as the magnitude of the first current I1 supplied from the constant current power supply 5. Also, the first light source 1 and the second light source 2 are connected in parallel via the current mirror circuit 7, and the pseudo load 3 connected in parallel with the second light source 2 in accordance with the lighting cycle of the second light source 2. ON time is controlled. Therefore, since the first current I1 is supplied from the constant current power source 5, a constant voltage power source is not necessary, and since it is not resistance drive, it is possible to suppress power consumption of the entire circuit and heat generation due to power consumption. .. Further, since the first light source 1 and the second light source 2 are connected in parallel, even if one of them is controlled to be turned on and off and an overcurrent is generated, there is no possibility that the other will be burdened with a short life or damage. .. Further, the second light source 2 can be turned on in accordance with the lighting cycle by the ON time of the pseudo load 3 connected in parallel with the second light source 2. Therefore, it is possible to cope with the temperature change of the second light source 2, and it is also possible to perform blinking control or dimming control of the second light source 2. Therefore, while suppressing power consumption, it is possible to achieve a long life and facilitate blinking or dimming control.

Further, in the present embodiment, when the second current I2 is supplied to the second light source 2, the first switching element Q1 is controlled to be in the ON state. When the first switching element Q1 is controlled to be in the ON state, the first current I1 flows through the bypass circuit 9, so that the first light source 1 is turned off and the second switching element Q2 and the third switching element of the current mirror circuit 7 are turned off. Q5 can be controlled to the on state. Therefore, since the second current I2 can be passed through the second light source 2, the second light source 2 can be turned on without turning on the first light source 1.

Further, in the present embodiment, the magnitude of the first current I1 is controlled to the magnitude of the current according to the lighting of either the first light source 1 or the second light source 2. Therefore, the magnitude of the first current I1 is suitable for the first light source 1 when the first light source 1 is turned on, and is suitable for the second light source 2 when the second light source 2 is turned on. One current I1 does not become unnecessarily large. Therefore, the power consumption of the entire circuit can be suppressed, and the heat generation due to the power consumption can also be suppressed.

In addition, in the present embodiment, a plurality of second light sources 2 are provided in parallel. Since the pseudo load 3 is connected in parallel to the second light source 2 and the pseudo load 3 is connected to the current mirror circuit 7, the same second current I2 can flow through each of the second light sources 21 to 23. it can. Therefore, it is possible to realize a sequential turn in which the second light sources 21 to 23 are sequentially turned on. Further, since the second light sources 2 are connected in parallel, even if one of the second light sources 2 is controlled to be turned on and off and an overcurrent is generated, there is no possibility that the other light source is burdened with a short life or damage.

Although the vehicle lighting device to which the present disclosure is applied has been described above based on the embodiment, the present disclosure is not limited to this, and may be modified without departing from the gist of the present disclosure.

Further, for example, the example in which the current mirror circuit 7 has a one-stage configuration has been described, but the present invention is not particularly limited to this. For example, the second switching element Q2 and the third switching element Q5 may have a multi-stage configuration.

Also, for example, an example of the circuit configuration in which three second light sources 2 are connected in parallel to the current mirror circuit 7 has been described, but four or more second light sources 2 are connected in parallel to the current mirror circuit 7. It may have a circuit configuration.

1 1st light source 2, 21, 22, 23 2nd light source 3, 31, 32, 33 Pseudo load 5 Constant current power supply 61, 62 DC power supply 7 Current mirror circuit 8 PWM control circuit 9 Bypass circuit I1 1st current I2 2nd Current D11, D2, D21, D22, D23 Semiconductor light emitting device D5, D6 Diode C1, C11, C2, C21, C22, C23 Capacitor C3, C31, C32, C33 Pseudo capacitor R1 Resistance load R2 Resistance R3, R31, R32, R33 pseudo resistance Q1 first switching element Q2 second switching element Q3, Q31, Q32, Q33 pseudo switching element Q4 characteristic adjusting switching element Q5, Q51, Q52, Q53 third switching element GND chassis ground S1, S2 switch

Claims (4)

A vehicle lamp connected to a DC power supply,
A first light source,
A second light source,
A pseudo load connected in parallel with the second light source,
A constant current power supply for supplying a first current to the first light source,
The first light source and the second light source are connected in parallel, and the magnitude of the second current supplied from the DC power source to one of the second light source and the dummy load is set to the first value. A current mirror circuit that equalizes the magnitude of current,
A PWM control circuit connected between the constant current power supply and the DC power supply, for controlling lighting of the first light source and the second light source;
Equipped with
The PWM control circuit is
Controlling the on time of the pseudo load according to the lighting cycle of the second light source;
Vehicle lighting. A bypass circuit connected in parallel to the first light source and diverting the first current;
Further equipped with,
The bypass circuit is
A first switching element,
A resistive load connected in series with the first switching element,
Equipped with
The current mirror circuit is
A second switching element having a collector connected in series with the resistive load and an emitter connected to chassis ground;
A third switching element having a collector connected in series with the pseudo load and an emitter connected to chassis ground;
Equipped with
A collector and a base of the second switching element are connected, and respective bases of the second switching element and the third switching element are connected to each other,
The PWM control circuit is
When supplying the second current to the second light source, the first switching element is controlled to be in an ON state,
The vehicle lamp according to claim 1. The constant current power source,
Controlling the magnitude of the first current to the magnitude of the current according to the lighting of either the first light source or the second light source,
The vehicle lamp according to claim 1. The second light source is
Are provided in parallel,
The vehicle lamp according to any one of claims 1 to 3.

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