CN209355151U - Vehicle Headlamps - Google Patents

Abstract

An object of the present invention is to provide a vehicle headlamp which can be turned on stably. A vehicle headlamp (1) has: a first semiconductor light emitting element (L1) that emits light that becomes high beam; a second semiconductor light emitting element (L2a, L2b) that emits light that becomes low beam; a PTC thermistor device (R6), which is arranged on the path of current applied to at least one of the first semiconductor light emitting element (L1) and the second semiconductor light emitting element (L2a, L2b); and a switching circuit (SC), having a The above semiconductor switches switch the lighting and extinguishing of the first semiconductor light emitting element (L1), and at least one of the semiconductor switches and the PTC thermistor (R6) are mounted on the same substrate.

Description

Vehicle Headlamps

technical field

The utility model relates to a vehicle headlamp which can be stably lit.

Background technique

As a vehicle headlamp typified by an automobile headlamp, a headlamp having a light source for emitting a low beam and a light source for emitting a high beam is known. Such a vehicle headlamp is described in Patent Document 1 below.

In this vehicle headlamp, a semiconductor light emitting element for emitting light as low beam and a semiconductor light emitting element for emitting light as high beam are arranged on the same substrate, and a semiconductor light emitting element for controlling the lighting state of these semiconductor light emitting elements is arranged on the same substrate. The lighting control part is installed, and the area where the lighting control part is mounted and the area where the semiconductor light emitting element is mounted are separated. With such a structure, the influence of heat generated in each semiconductor light emitting element and the lighting control member is mutually reduced, and the semiconductor light emitting element can emit light stably.

prior art literature

Patent Document 1: (Japanese) Unexamined Patent Publication No. 2016-105372

Utility model content

In addition to reducing the influence of heat by the layout of the substrate as described in the above-mentioned Patent Document 1, there is also a method of suppressing the influence of heat by the components of the circuit. A thermistor having a positive temperature coefficient (PTC thermistor) is known as a component for suppressing the influence of heat in an electric circuit. In the case of using a PTC thermistor, it is considered to arrange a PTC thermistor on the route of applying current to the semiconductor light-emitting element, and when the heat generation of the lighting control part increases, the PTC thermistor reduces the impact on the semiconductor light-emitting element. The amount of current applied to the light emitting element. However, when the ambient temperature of the vehicle headlamp is very low, even if the lighting control part generates heat, the resistance of the PTC thermistor is difficult to increase, and the adjustment of the amount of current flowing through the semiconductor light emitting element is insufficient. There is a concern that the light emission of the semiconductor light emitting element may not be stable.

Therefore, an object of the present invention is to provide a vehicle headlamp that can be turned on stably.

In order to achieve the above object, the vehicle headlamp of the present utility model is characterized in that it has: a first semiconductor light-emitting element that emits light that becomes high beam; a second semiconductor light-emitting element that emits light that becomes low beam; a sensitive resistor disposed on a path of current applied to at least one of the first semiconductor light emitting element and the second semiconductor light emitting element; and a switching circuit having one or more semiconductor switches, and switching For turning on and off of the first semiconductor light emitting element, at least one of the semiconductor switches and the PTC thermistor are mounted on the same substrate.

In such a vehicle headlamp, the temperature of the PTC thermistor increases and the resistance increases, so that the magnitude of the current flowing through the semiconductor light emitting element to which the current is applied from the current path where the PTC thermistor is placed can be reduced. The brightness emitted from the semiconductor light emitting element is adjusted. Moreover, a bipolar transistor, a field effect transistor (FET: Field Effect Transistor), etc. can be mentioned as a semiconductor switch of a switching circuit. These semiconductor switches tend to generate heat. Accordingly, heat generated from the semiconductor switch disposed on the same substrate as the PTC thermistor is transferred to the PTC thermistor. Therefore, even when the ambient temperature is low, the PTC thermistor can be properly operated, and the semiconductor light emitting element to which a current is applied from the current path in which the PTC thermistor is placed can be stably emitted. Therefore, with the vehicle headlamp of the present invention, stable lighting can be realized.

Furthermore, it is preferable that a slit is formed in the substrate between at least one of the semiconductor light emitting elements and at least a part of the PTC thermistor.

By mounting at least one of the semiconductor switches and the PTC thermistor on the same substrate as described above, heat from the semiconductor switch can be transferred to the PTC thermistor. On the other hand, sometimes the heat from the semiconductor switch is not transferred to the PTC thermistor as well. Therefore, by forming a slit between at least one of the semiconductor switches and at least a part of the PTC thermistor as described above, it is possible to adjust the amount of transferred heat.

In addition, it is preferable to further include a first resistor connected in parallel to the first semiconductor light emitting element, and the switching circuit switches the path of current so that current flows through the first semiconductor light emitting element and the first semiconductor light emitting element. one of the resistors.

With such a structure, when the current does not flow through the first semiconductor light emitting element, the current flows through the first resistor. Therefore, the load of other circuits can be suppressed from changing when the first semiconductor light emitting element emits light and when it is not emitting light, and more stable lighting can be realized.

In this case, it is preferable that the first semiconductor light emitting element and the first resistor are mounted on the same substrate.

When the current flows through the first semiconductor light emitting element, the first semiconductor light emitting element generates heat, and when the current does not flow through the first semiconductor light emitting element as described above, the current flows through the first resistor, so the first resistor generates heat. Therefore, by mounting the first semiconductor light emitting element and the first resistor on the same substrate, it is possible to suppress a change in temperature of the substrate on which the first semiconductor light emitting element is mounted between when the high beam is turned on and when the high beam is not turned on. Therefore, the light emission of the first semiconductor light emitting element can be further stabilized.

Furthermore, it is preferable that the first semiconductor light emitting element and the second semiconductor light emitting element are connected in series.

At this time, the PTC thermistor is arranged on the path of the current applied to the first semiconductor light emitting element and the second semiconductor light emitting element. Therefore, in this case, it is possible to stabilize the lighting of both the low beam and the high beam.

In addition, it is preferable to further include a second resistor connected in series to the PTC thermistor.

PTC thermistor sometimes has its resistance value rise sharply at a specified temperature. However, by arranging the above-mentioned second resistor, even if the resistance value of the PTC thermistor rises, compared with the case where there is no second resistor, it is possible to suppress the The ratio of the resistance value rise can suppress the excessive influence of the change of the resistance value of the PTC thermistor.

In addition, it is preferable that a slit is formed on the substrate between at least a part of the second resistor and at least a part of the PTC thermistor.

As mentioned above, the second resistor is connected in series with the PTC thermistor, so the heat generated from the second resistor is easily transferred to the PTC thermistor through the wiring, and furthermore, there is a possibility that the heat is also transferred to the PTC from parts other than the wiring on the substrate. Thermistor tendencies. Therefore, heat transfer from the second resistor to the PTC thermistor can be suppressed by the slit formed in the substrate.

In addition, it is preferable that the vehicle headlamp further has: a third semiconductor light emitting element that emits light that becomes high beam; a fourth semiconductor light emitting element that emits light that becomes low beam; and a second PTC thermistor that emits light that becomes low beam. arranged on a path of current applied to at least one of the third semiconductor light emitting element and the fourth semiconductor light emitting element, the switching circuit switches on and off of the third semiconductor light emitting element, the At least one of the semiconductor switches is mounted on the same substrate as the second PTC thermistor.

In this way, the vehicle headlamp can reduce the amount of light emitted per semiconductor light emitting element by including the third semiconductor light emitting element and the fourth semiconductor light emitting element. In addition, even in such a case, the current value of the current flowing through the semiconductor light emitting element from which the second PTC thermistor is disposed can be adjusted, and the amount of light emitted from the semiconductor light emitting element can be adjusted. path to which current is applied. Furthermore, the heat generated from the semiconductor switch disposed on the same substrate as the second PTC thermistor is transferred to the second PTC thermistor, so that the second PTC thermistor can device works properly. Accordingly, it is possible to stably emit light from the semiconductor light emitting element to which a current is applied from the current path in which the second PTC thermistor is arranged.

In this case, preferably, a slit is formed on the substrate between at least one of the semiconductor switches and at least a part of the second PTC thermistor.

In this case, the amount of heat transferred from at least one of the semiconductor switches to the second PTC thermistor can be adjusted.

Furthermore, preferably, the slit between the semiconductor switch and the PTC thermistor is a different slit from the slit between the semiconductor switch and the second PTC thermistor.

In this case, the heat transferred from the semiconductor switch to the PTC thermistor arranged on the path of the current applied to at least one of the first semiconductor light emitting element and the second semiconductor light emitting element can be individually adjusted through each slit, And heat transferred from the semiconductor switch to the second PTC thermistor disposed on a path of current applied to at least one of the third semiconductor light emitting element and the fourth semiconductor light emitting element.

In addition, it is preferable to have a third resistor connected in parallel to the third semiconductor light emitting element, and the switching circuit switches the path of current so that the current flows through the third semiconductor light emitting element and the third semiconductor light emitting element. one of the resistors.

At this time, when the current does not flow through the third semiconductor light emitting element, the current flows through the third resistor. Therefore, it is possible to suppress the load of other circuits from changing when the third semiconductor light emitting element emits light and when it does not emit light, and more stable lighting can be realized.

In this case, it is preferable that the third semiconductor light emitting element and the third resistor are mounted on the same substrate.

When the current flows through the third semiconductor light emitting element, the third semiconductor light emitting element generates heat. When the current does not flow through the third semiconductor light emitting element as described above, the current flows through the third resistor, so the third resistor generates heat. Therefore, by mounting the third semiconductor light emitting element and the third resistor on the same substrate, it is possible to suppress a change in temperature of the substrate on which the third semiconductor light emitting element is mounted when the high beam is turned on and when the high beam is turned off. Therefore, the light emission of the third semiconductor light emitting element can be further stabilized.

In addition, it is preferable to further include a fourth resistor connected in series with the second PTC thermistor.

By disposing such a fourth resistor, compared with the case without the fourth resistor, even when the resistance value of the second PTC thermistor rises, it is possible to suppress the connection between the second PTC thermistor and the fourth resistor. The rate at which the added resistance value rises can suppress the influence of the change in the resistance value of the second PTC thermistor from being too large.

In addition, it is preferable that a slit is formed on the substrate between at least a part of the fourth resistor and at least a part of the second PTC thermistor.

Since the fourth resistor is connected in series with the second PTC thermistor as described above, the heat generated from the fourth resistor is easily transferred to the second PTC thermistor via the wiring, and there is a possibility that the heat is transmitted from other than the wiring on the substrate to the second PTC thermistor. sites are also prone to transfer to the PTC thermistor. Therefore, the transfer of heat from the fourth resistor to the second PTC thermistor can be suppressed by the slit formed on the substrate.

In addition, the first semiconductor light emitting element, the second semiconductor light emitting element, and the switching circuit may be mounted on the same substrate.

In this case, the structure can be simplified compared to the case where the first semiconductor light emitting element, the second semiconductor light emitting element, and the switching circuit are distributed and mounted on a plurality of substrates.

In addition, the first semiconductor light emitting element and the second semiconductor light emitting element may be mounted on a substrate different from the substrate on which the switching circuit is mounted.

In this case, it is possible to suppress heat generated from the first semiconductor light emitting element and the second semiconductor light emitting element from being transferred to the substrate on which the switching circuit or the PTC thermistor is mounted. Therefore, it is possible to suppress the influence of the heat generated from the first semiconductor light emitting element and the second semiconductor light emitting element on the operation of the PTC thermistor.

Furthermore, as described above, when the first semiconductor light emitting element and the second semiconductor light emitting element are mounted on a substrate different from the substrate on which the switching circuit is mounted, the first semiconductor light emitting element may be mounted on the same substrate as the second semiconductor light emitting element.

In this case, the structure can be simplified compared to the case where the first semiconductor light emitting element and the second semiconductor light emitting element are mounted on different substrates.

Alternatively, as described above, when the first semiconductor light emitting element and the second semiconductor light emitting element are mounted on a substrate different from the substrate on which the switching circuit is mounted, the first semiconductor light emitting element may be and the second semiconductor light emitting element are mounted on a substrate different from each other.

In this case, the degree of freedom in design such as the design of the vehicle headlamp can be improved. In addition, it is possible to suppress the transfer of heat generated from the first semiconductor light emitting element to the substrate on which the second semiconductor light emitting element is mounted. Therefore, it is possible to suppress a temperature change of the substrate on which the second semiconductor light emitting element is mounted due to light emission and extinction of the first semiconductor light emitting element.

In addition, the first semiconductor light emitting element, the second semiconductor light emitting element, the third semiconductor light emitting element, the fourth semiconductor light emitting element, and the switching circuit may be mounted on the same substrate.

In this case, the structure can be simplified compared to the case where the first semiconductor light emitting element, the second semiconductor light emitting element, the third semiconductor light emitting element, the fourth semiconductor light emitting element, and the switching circuit are mounted on different substrates.

In addition, the first semiconductor light emitting element, the second semiconductor light emitting element, the third semiconductor light emitting element, and the fourth semiconductor light emitting element may be mounted on a different substrate from the switching circuit.

In this case, heat generated from the first semiconductor light emitting element, the second semiconductor light emitting element, the third semiconductor light emitting element, and the fourth semiconductor light emitting element can be suppressed from being transferred to the substrate on which the switching circuit or the PTC thermistor is mounted. Therefore, it is possible to suppress the influence of heat generated from these semiconductor light emitting elements on the operation of the PTC thermistor.

In this case, the first semiconductor light emitting element and the second semiconductor light emitting element may be mounted on the same substrate, and the third semiconductor light emitting element and the fourth semiconductor light emitting element may be mounted on the same substrate, so The first semiconductor light emitting element and the second semiconductor light emitting element, and the third semiconductor light emitting element and the fourth semiconductor light emitting element are mounted on different substrates.

Alternatively, the first semiconductor light emitting element, the second semiconductor light emitting element, the third semiconductor light emitting element, and the fourth semiconductor light emitting element may all be mounted on different substrates.

In this case, the degree of freedom in design such as the design of the vehicle headlamp can be improved. In addition, it is possible to suppress transfer of heat generated from each semiconductor light emitting element to a substrate on which other semiconductor light emitting elements are mounted.

As described above, according to the present invention, it is possible to provide a vehicle headlamp that can be turned on stably.

Description of drawings

FIG. 1 is a front view showing a vehicle headlamp according to a first embodiment of the present invention.

Fig. 2 is a sectional view taken along line II-II of the vehicle headlamp in Fig. 1 .

Fig. 3 is a sectional view taken along line III-III of the vehicle headlamp in Fig. 1 .

4 is a circuit diagram of the vehicle headlamp in the first embodiment of the present invention.

FIG. 5 is a plan view showing the substrate of FIG. 1 .

6(A) and 6(B) are diagrams showing light distribution.

FIG. 7 is a diagram showing a circuit diagram of a vehicle headlamp in a second embodiment of the present invention in the same manner as in FIG. 4 .

FIG. 8 is a diagram showing a circuit diagram of a vehicle headlamp in a third embodiment of the present invention in the same manner as in FIG. 4 .

FIG. 9 is a diagram showing a circuit diagram of a vehicle headlamp in a fourth embodiment of the present invention in the same manner as in FIG. 4 .

FIG. 10 is a diagram showing a circuit diagram of a vehicle headlamp in a fifth embodiment of the present invention in the same manner as in FIG. 4 .

FIG. 11 is a diagram showing a circuit diagram of a vehicle headlamp in a sixth embodiment of the present invention in the same manner as in FIG. 4 .

FIG. 12 is a plan view showing a substrate on which the switching circuit of FIG. 11 is mounted.

FIG. 13 is a plan view showing all the substrates in FIG. 11 .

FIG. 14 is a diagram showing a circuit diagram of a vehicle headlamp in a seventh embodiment of the present invention in the same manner as in FIG. 4 .

FIG. 15 is a diagram showing a circuit diagram of a vehicle headlamp in an eighth embodiment of the present invention in the same manner as in FIG. 4 .

FIG. 16 is a plan view showing a substrate on which the switching circuit of FIG. 15 is mounted.

FIG. 17 is a plan view showing all the substrates in FIG. 15 .

Label description

1 Headlights for vehicles

10 housing

31, 32a, 32b reflector

50 substrates

50S, 50Sa, 50Sb slit

51 Substrate

51S, 51Sa, 51Sb Slits

52, 52a, 52b, 53, 53a, 53b, 54, 54a, 54b Substrate

FT2, FT3 transistors (semiconductor switches)

L1 The first semiconductor light emitting element

L2a, L2b second semiconductor light emitting element

L3 third semiconductor light emitting element

L4a, L4b fourth semiconductor light emitting element

LH First Luminaire

LLa, LLb Second luminaire

LU light unit

R6 PTC thermistor

R7 resistor (second resistor)

R8 resistor (first resistor)

R9 (second) PTC thermistor

R10 resistor (fourth resistor)

R11 resistor (third resistor)

SC switching circuit

TR1 transistor (semiconductor switch)

Detailed ways

Hereinafter, an embodiment for implementing the vehicle headlamp according to the present invention will be illustrated together with the drawings. The following exemplary embodiments are used to facilitate understanding of the present invention, and are not intended to limit interpretation of the present invention. The present invention can be changed and improved based on the following embodiments without departing from the gist.

(first embodiment)

Fig. 1 is a front view showing a vehicle headlamp according to a first embodiment of the present invention, Fig. 2 is a cross-sectional view of II-II of the vehicle headlamp of Fig. 1 , and Fig. 3 is a vehicle headlamp Sectional view of III-III.

As shown in FIGS. 1 to 3 , the vehicle headlamp 1 includes a housing 10 and a lamp unit LU accommodated in the housing 10 . In addition, although omitted in FIGS. 1 to 3 , the vehicle headlamp 1 has a concealing member that conceals unnecessary portions of the lamp unit LU when the vehicle headlamp 1 is viewed from the front.

The housing 10 has a lamp cover 11 and a front cover 12 as main structural elements. In addition, in FIG. 1, description of the front cover 12 is abbreviate|omitted from a viewpoint of making a figure easy to see. As shown in FIGS. 2 and 3 , the front of the globe 11 is opened, and the light-transmitting front cover 12 is fixed to the globe 11 so as to close the opening.

The space formed by the globe 11 and the front cover 12 which closes the front opening of this globe 11 becomes a lamp chamber LR, and the lamp unit LU is accommodated in this lamp chamber LR.

As shown in FIG. 1 , the lamp unit LU has a first lamp LH for emitting high beams, and a pair of second lamps LLa and LLb for emitting low beams. The first lamp LH and the second lamps LLa and LLb share the board 50 .

The 1st lamp LH has the 1st semiconductor light emitting element L1 which consists of LED (Light Emitting Diode) etc., and the reflector 31 as a main structure. The first semiconductor light emitting element L1 is mounted on one surface of the substrate 50 . In addition, the reflector 31 is formed by applying plating to a reflector main body made of resin, and the plated surface becomes a light reflection surface 31r.

The reflective surface 31r has a concave shape formed of a free curved surface that becomes a parabola on the front side based on the opening direction. More specifically, the shape of the reflection surface 31r in the vertical cross section is substantially lower than the apex of the parabola, and the shape of the reflection surface 31r in the horizontal cross section is substantially including the apex of the parabola. Wherein, the parabola of the reflective surface 31 r on the cross section in the vertical direction and the parabola on the cross section in the horizontal direction may be different parabolas from each other. In addition, the shape of the reflection surface 31r in the vertical direction and the horizontal cross-section may not be a shape based on a parabola, but may be a shape based on a part of an ellipse or another concave shape, for example.

The reflector 31 is arranged such that the reflective surface 31r surrounds the first semiconductor light emitting element L1. Accordingly, the light emitted from the first semiconductor light emitting element L1 is reflected on the reflective surface 31 r of the reflector 31 , and is emitted from the front opening of the reflector 31 .

The second lamp LLa has a second semiconductor light emitting element L2a made of LEDs and the like and a reflector 32a as its main structure, and the second lamp LLb has a second semiconductor light emitting element L2b made of LEDs and the like and a reflector 32b as its main structures. As a result, the second lamp LLa and the second lamp LLb have substantially symmetrical shapes with respect to each other.

The second semiconductor light emitting elements L2a and L2b are mounted on the other surface of the substrate 50 . In addition, the reflectors 32a and 32b are constructed by applying plating to the reflector main body made of resin, and the plated surfaces of the reflectors 32a and 32b serve as light reflection surfaces 32ar and 32br.

Similar to the reflector 31 , the reflection surfaces 32ar and 32br of the reflectors 32a and 32b each have a concave shape formed of a free curved surface that becomes a parabola on the front side based on the opening direction. More specifically, the shape of the reflective surfaces 32ar and 32br in the cross section in the vertical direction is substantially lower than the apex of the parabola, and the shape of the reflective surfaces 32ar and 32br in the cross section in the horizontal direction is substantially including the apex of the parabola. shape. However, similarly to the reflector 31 , the parabola on the cross section in the vertical direction and the parabola on the cross section in the horizontal direction of the reflecting surfaces 32ar and 32br may be different parabolas from each other. In addition, the shapes of the reflection surfaces 32ar and 32br in the vertical and horizontal cross-sections may not be based on a parabola, but may be based on a part of an ellipse or other concave shapes, for example. Such reflectors 32a and 32b are coupled to each other, and the space surrounded by the reflective surface 32ar and the space surrounded by the reflective surface 32br are coupled to each other in the left-right direction.

The reflector 32a is arranged such that the reflective surface 32ar surrounds the second semiconductor light emitting element L2a, and the reflector 32b is arranged such that the reflective surface 32br surrounds the second semiconductor light emitting element L2b. Thereby, the light emitted from the second semiconductor light emitting element L2a is reflected on the reflecting surface 32ar of the reflector 32a, thereby emitting from the opening in front of the reflector 32a, and the light emitted from the second semiconductor light emitting element L2b is reflected on the reflecting surface 32b of the reflector 32b. 32br to emit from the opening in front of the reflector 32b.

The lamp unit LU in which the first lamp LH and the second lamps LLa and LLb are integrated is fixed to the casing 10 so that the light emission direction can be adjusted. Specifically, as shown in FIGS. 1 to 3 , the vehicle headlamp 1 has an adjustment portion 60 capable of adjusting the orientation of the lamp unit LU, and the lamp unit LU is fixed to the housing 10 via the adjustment portion 60 .

The adjusting part 60 has a pivot part 61 and an aiming screw part 62. The pivot part 61 has a pivot shaft 61a and a ball joint part 61b. The standard adjusting screw part 62 has a shaft part 62a and an operating part 62b.

One end of the pivot 61a is fixed to the lamp unit LU, and the other end is spherical. This spherical end portion is rotatably fitted into a ball joint 61 b fixed to the housing 10 . In addition, the vehicle headlamp 1 according to the present embodiment includes one pivot portion 61 in the vicinity of the left and right end portions of the lamp unit LU.

A nut 64 is fixed to the lamp unit LU, and a helical groove is formed at one end of the shaft portion 62 a of the aiming adjustment screw portion 62 , and the nut 64 is screwed into the helical groove. In addition, the shaft portion 62 a is rotatably fixed to the housing 10 , and the other end of the shaft portion 62 a is drawn out to the outside of the housing 10 . The operation part 62b is fixed to the other end of the shaft part 62a, and when the operation part 62b is rotated, the shaft part 62a will rotate along with the rotation of the operation part 62b. By the rotation of the shaft part 62a, the nut 64 moves along the longitudinal direction of the shaft part 62a. Through this operation, the lamp unit LU can be tilted with respect to the casing 10 . By tilting the lamp unit LU, the vertical angle of the light emitted from the lamp unit LU can be adjusted.

Next, the substrate 50 will be described in detail. In addition, the connection in the description of a circuit may include an electrical connection.

FIG. 4 is a circuit diagram showing a circuit formed by wiring on the substrate 50 and electronic components mounted on the substrate 50 . In FIG. 4 , the substrate 50 is generally indicated by a dotted line. As shown in FIG. 4 , in this circuit, a switching circuit SC indicated by a dotted line is included. The switching circuit SC includes one or more semiconductor switches, and is a circuit for switching on and off of the first lamp LH that emits high beams, that is, switching between lighting and non-lighting of the first semiconductor light emitting element L1.

In this circuit, one electrode of the PTC thermistor R6 is connected to the terminal LO for inputting electric power for making the first semiconductor light emitting element L1, the second semiconductor light emitting element L2a, L2b emit light, and the terminal LO and the PTC thermistor One electrode of R6 is connected to one electrode of resistor R2 of switching circuit SC. In addition, one electrode of a resistor R7 as a second resistor is connected to the other electrode of the PTC thermistor R6. The other electrode of the resistor R7 is connected to the anode of the second semiconductor light emitting element L2a, the cathode of the second semiconductor light emitting element L2a is connected to the anode of the second semiconductor light emitting element L2b, and the cathode of the second semiconductor light emitting element L2b is connected to the first semiconductor light emitting element. anode of element L1. That is, the terminal LO, the PTC thermistor R6, the resistor R7, the second semiconductor light emitting element L2a, the second semiconductor light emitting element L2b, and the first semiconductor light emitting element L1 are connected in series. In addition, one electrode of a resistor R8 serving as a first resistor is connected to the cathode of the second semiconductor light emitting element L2b and the anode of the first semiconductor light emitting element L1. That is, the first semiconductor light emitting element L1 and the resistor R8 are connected in parallel. In addition, in the present embodiment, the magnitude of the resistance of the first semiconductor light emitting element L1 is substantially equal to the magnitude of the resistance of the resistor R8.

Furthermore, a terminal HI for inputting a control signal for controlling the lighting and extinguishing of the first lamp LH is connected to the switching circuit SC. The anode of the diode D1 is connected to the terminal HI, and the Zener diode ZD3 is connected to the reverse bias of the diode D1. Therefore, the cathode of Zener diode ZD3 is connected to the cathode of diode D1. In addition, one electrode of the resistor R1 is connected to the cathode of the diode D1 and the cathode of the Zener diode ZD3 , and the other electrode of the resistor R1 is connected to the ground GND. The anode of the Zener diode ZD3 is connected to the base of the bipolar transistor TR1 which is one of semiconductor switches via a resistor. The other electrode of the resistor R2 is connected to the collector of the transistor TR1, and one electrode of the resistor R2 is connected to the terminal LO and one electrode of the PTC thermistor R6. In addition, the emitter of the transistor TR1 is connected to the ground line GND, and further connected to the base of the transistor TR1 via a resistor. In addition, the gate of field effect transistor FT2, which is one of the semiconductor switches, and one electrode of resistor R3 are connected to the collector of transistor TR1 and the other electrode of resistor R2, and the other electrode of resistor R3 is connected to the ground line GND. . The drain of the transistor FT2 is connected to the other electrode of the resistor R8, and one electrode of the resistor R8 is connected to the cathode of the second semiconductor light emitting element L2b and the anode of the first semiconductor light emitting element L1. The source of the transistor FT2 is connected to the ground GND. In addition, the anode of the Zener diode ZD3 and the base of the transistor TR1 are connected to one electrode of the resistor R4, and the other electrode of the resistor R4 is connected to the gate of the field effect transistor FT3 as one of the semiconductor switches and an electrode of the resistor R5. The other electrode of R5 is connected to the ground GND. The cathode of the first semiconductor light emitting element L1 is connected to the drain of the transistor FT3, and the source of the transistor FT3 is connected to the ground GND.

FIG. 5 is a plan view showing the substrate 50 . In FIG. 5 , the substrate 50 is shown from one side. As shown in FIG. 5 , in this embodiment, the substrate 50 roughly presents a pentagonal shape. On the substrate 50, a switching circuit SC, a PTC thermistor R6, resistors R7, R8, a first semiconductor light-emitting diode L1, and a first semiconductor light-emitting diode L1 are mounted. Two semiconductor light emitting elements L2a, L2b. In addition, the substrate 50 is a substrate on which components are mounted on both sides, and the first semiconductor light emitting element L1, transistor TR1, transistors FT2, FT3, resistors R2, R3, R4, R5, diode D1, Zener diode ZD3, and PTC thermistor R6. On the other surface of the substrate 50, second semiconductor light emitting elements L2a, L2b, and resistors R1, R7, and R8 are mounted.

In addition, the resistor represented by one in the circuit diagram shown in FIG. 4 is sometimes composed of a plurality of elements. For example, resistors R1, R7, R8, etc. are connected in series or in parallel by a plurality of resistive elements, and are represented as one resistor in the circuit diagram. . In addition, the PTC thermistor R6 may be composed of a plurality of elements, but in this embodiment, an example in which the PTC thermistor R6 is composed of four PTC thermistor elements connected in parallel is shown. In FIG. 5 , these plural elements are given reference numerals surrounded by dotted lines.

In addition, in the case of facing the substrate 50, on the substrate 50, at least one of the transistor TR1 as one of the semiconductor switches and the transistors FT2 and FT3 as one of the semiconductor switches, and at least one of the PTC thermistor R6 A slit 50S is formed between them. In this embodiment, a plurality of slits 50S are formed. These slits 50S are also schematically shown in FIG. 4 . However, in FIG. 4 , a plurality of slits 50S are collectively described as one. In this embodiment, the slit 50S is formed between the transistor TR1 and the whole of the PTC thermistor R6, and the slit 50S is formed between the transistors FT2 and FT3 and a part of the PTC thermistor R6. In addition, the slit 50S is also formed between at least a part of the PTC thermistor R6 and at least a part of the resistor R7 connected in series with the PTC thermistor R6. However, in FIG. 4 , the scene where the slit 50S is formed at this position is omitted. Furthermore, in the present embodiment, a plurality of openings are formed around the PTC thermistor R6 of the substrate 50, and these openings serve as through holes for arranging conductors on the inner wall surface. In addition, when a plurality of openings are formed around the PTC thermistor R6 in this way, conductors may not be disposed on the inner wall surfaces of the openings.

Next, the operation and effects of the vehicle headlamp 1 of the present embodiment will be described.

<When low beam is on>

In each case of turning on the low beam and the high beam, a voltage for causing the semiconductor light emitting element to emit light is applied to the terminal LO. This voltage is, for example, 12V. When the low beam is turned on, the voltage of the terminal HI becomes a low level. The low-level state includes a state where the voltage is 0V. Since the voltage of terminal HI is at low level, Zener diode ZD3 does not cause Zener breakdown, the voltage on the anode side of Zener diode ZD3 remains low, and the voltage applied to the base of transistor TR1 also becomes low. flat. Accordingly, the transistor TR1 is turned off, and the flow of current between the collector and the emitter of the transistor TR1 is suppressed. Therefore, the voltage applied to the terminal LO is applied to the gate of the transistor FT2 via the resistor R2, and a current flows between the drain and the source of the transistor FT2. Also, since the voltage on the anode side of the Zener diode ZD3 becomes low level, the gate voltage of the transistor FT3 becomes low level, and the transistor FT3 is turned off. Accordingly, the flow of current between the drain and the source of the transistor FT3 is suppressed. With such a state, the current flowing from the terminal LO flows through the second semiconductor light emitting elements L2a, L2b via the PTC thermistor R6 and the resistor R7. As described above, the flow of current between the drain and the source of the transistor FT3 is suppressed, and the current flows between the drain and the source of the transistor FT2. Therefore, the current flowing through the second semiconductor light emitting elements L2a and L2b is suppressed from flowing to the first semiconductor light emitting element L1, flows through the resistor R8, and flows through the ground line GND via the transistor FT2.

In this way, the light emission of the first semiconductor light emitting element L1 is suppressed, and the second semiconductor light emitting elements L2a, L2b emit light. Light emitted from the second semiconductor light emitting elements L2a, L2b is reflected on the emitting surfaces 32ar, 32br of the reflectors 32a, 32b shown in FIGS. In this way, the low beam is turned on.

Fig. 6 is a diagram showing light distribution. Specifically, FIG. 6(A) shows the light distribution of the low beam, and FIG. 6(B) shows the light distribution of the high beam. Therefore, in the lighting state of the low beam described above, the light distribution shown in FIG. 6(A) is obtained.

<When high beams are on>

When the high beams are turned on, the voltage of the terminal HI becomes a high level. When the voltage of the terminal HI is at a high level, a voltage of, for example, 12V is applied to the terminal HI. Since the voltage of terminal HI is HI, Zener diode ZD3 causes Zener breakdown, and the voltage on the anode side of Zener diode ZD3 becomes high level. Therefore, the voltage applied to the base of the transistor TR1 becomes a high level, the transistor TR1 is turned on, and a current flows between the collector and the emitter of the transistor TR1. Therefore, the voltage applied to the terminal LO is connected to the ground line GND via the resistor R2 and the transistor TR1. Accordingly, the voltage applied to the gate of the transistor FT2 becomes low level, and the flow of current between the drain and the source of the transistor FT2 is suppressed. In addition, the voltage on the anode side of the Zener diode ZD3 becomes high level, the gate voltage of the transistor FT3 becomes high level, and the transistor FT3 is turned on. Accordingly, a current flows between the drain and the source of the transistor FT3. With such a state, the current flowing from the terminal LO flows through the second semiconductor light emitting elements L2a, L2b via the PTC thermistor R6 and the resistor R7. As described above, the current flows between the drain and the source of the transistor FT3, and the current flowing between the drain and the source of the transistor FT2 is suppressed, so the current flowing through the second semiconductor light emitting elements L2a, L2b is suppressed. It flows through the resistor R8, flows through the first semiconductor light emitting element L1, and flows through the ground line GND through the transistor FT3.

In this way, the first semiconductor light emitting element L1 and the second semiconductor light emitting elements L2a, L2b emit light. Light emitted from the second semiconductor light emitting elements L2a, L2b is reflected on the reflective surfaces 32ar, 32br of the reflectors 32a, 32b as described above, and is emitted from the vehicle headlamp 1 via the front cover 12 . The light emitted from the first semiconductor light emitting element L1 is reflected on the reflective surface 31 r of the reflector 31 shown in FIGS. 1 to 3 , and is emitted from the vehicle headlamp 1 via the front cover 12 . In this way, the high beam is turned on, and the light distribution shown in FIG. 6(B) is obtained.

As described above, in the vehicle headlamp 1 of the present embodiment, the PTC thermistor R6 is arranged on the path of the current applied to the first semiconductor light emitting element L1 and the second semiconductor light emitting elements L2a, L2b. Therefore, the temperature of the PTC thermistor R6 rises and the resistance increases, thereby reducing the current value of the current flowing through the first semiconductor light emitting element L1, the second semiconductor light emitting element L2a, and L2b, and adjusting the current value from the first semiconductor light emitting element. L1, the light emitted by the second semiconductor light emitting element L2a, L2b, wherein the first semiconductor light emitting element L1, the second semiconductor light emitting element L2a, L2b are supplied with current from the current path where the PTC thermistor R6 is arranged.

In addition, in the vehicle headlamp 1 of the present embodiment, the transistor TR1 as a semiconductor switch, the transistors FT2 and FT3 , and the PTC thermistor R6 are mounted on the same substrate 50 . Semiconductor switches such as bipolar transistors and field effect transistors used as semiconductor switches tend to generate heat. Accordingly, heat generated from the semiconductor switch disposed on the same substrate 50 as the PTC thermistor R6 is transferred to the PTC thermistor R6. Therefore, even when the ambient temperature is low, it is possible to suppress that the PTC thermistor R6 does not operate properly without increasing the temperature of the PTC thermistor R6. Accordingly, it is possible to stably emit light to the first semiconductor light emitting element L1 and the second semiconductor light emitting elements L2a and L2b to which a current is applied from the current path in which the PTC thermistor R6 is arranged. Therefore, according to the vehicle headlamp 1 of the present embodiment, it is possible to stably light up.

In addition, in the vehicle headlamp 1 of the present embodiment, between at least one of the transistor TR1 and the transistors FT2 and FT3 which are semiconductor switches, and at least a part of the PTC thermistor R6, a circuit breaker is formed on the substrate 50. Slit 50S. As described above, the transistor TR1 and the transistors FT2 and FT3 are mounted on the same substrate 50 as the PTC thermistor R6, so that heat from the transistor TR1 and the transistors FT2 and FT3 can be transferred to the PTC thermistor R6. On the other hand, sometimes it is better not to transfer the heat from the transistor TR1 and the transistors FT2 and FT3 to the PTC thermistor R6 too much. Therefore, by forming the slit 50S between the transistor TR1 and at least one of the transistors FT2 and FT3 , and at least a part of the PTC thermistor R6 as described above, it is possible to adjust the amount of transferred heat.

In addition, in the vehicle headlamp 1 of the present embodiment, the switching circuit SC switches the path of the current so that the current flows through one of the first semiconductor light emitting element L1 and the resistor R8 as the first resistor. Therefore, when the current does not flow through the first semiconductor light emitting element L1, the current flows through the resistor R8, and power is consumed in the resistor R8. Therefore, it is possible to suppress a change in the load of other circuits when the first semiconductor light emitting element L1 emits light and when it does not emit light, and more stable lighting can be achieved.

Furthermore, in the vehicle headlamp 1 of the present embodiment, the first semiconductor light emitting element L1 and the resistor R8 are mounted on the same substrate 50 . When the current flows through the first semiconductor light emitting element L1, the first semiconductor light emitting element L1 generates heat, and when the current does not flow through the first semiconductor light emitting element L1, a current flows through the resistor R8 as the first resistor and the resistor R8 generates heat. Therefore, by mounting the first semiconductor light emitting element L1 and the resistor R8 on the same substrate 50, the temperature of the substrate 50 on which the first semiconductor light emitting element L1 is mounted can be suppressed from changing between high beam lighting and low beam lighting. That is to say, the heat generated by the resistor R8 is transferred to the substrate 50 when the low beam is turned on, so immediately after switching from the low beam to the high beam, the substrate 50 is already warmed by the heat generated by the resistor R8. Therefore, compared with the case where the resistor R8 and the substrate 50 are mounted on different substrates, it is possible to reduce the temperature of the substrate 50 immediately after the high beam is turned on, and the temperature of the substrate 50 immediately after switching from the low beam to the high beam. Difference. Therefore, the light emission of the first semiconductor light emitting element L1 can be further stabilized.

In addition, in the vehicle headlamp 1 of the present embodiment, the first semiconductor light emitting element L1 and the second semiconductor light emitting elements L2a, L2b are connected in series. Therefore, the PTC thermistor R6 is arranged in the path of the current applied to the first semiconductor light emitting element L1 and the second semiconductor light emitting elements L2a, L2b, and both the low beam and the high beam can be stably turned on.

Furthermore, the vehicle headlamp 1 of the present embodiment has a resistor R7 as a second resistor connected in series with the PTC thermistor. The resistance value of PTC thermistor R6 sometimes rises sharply at a specified temperature. However, by arranging the resistor R7 like the vehicle headlamp 1 of this embodiment, compared with the case without the resistor R7, even when the resistance value of the PTC thermistor R6 increases, it is possible to suppress heating of the PTC. The rising ratio of the resistance value added by the sensitive resistor R6 and the resistor R7 can suppress the excessive influence of the change of the resistance value of the PTC thermistor R6.

Moreover, in this embodiment, the slit 50S is formed in the board|substrate 50 between at least a part of resistor R7, and at least a part of PTC thermistor R6. This resistance R7 is connected in series with the PTC thermistor R6, so the heat generated from the resistance R7 is easily transmitted to the PTC thermistor R6 through the wiring, and further, the heat is also transmitted to the PTC heat from parts other than the wiring of the substrate 50. Sensitive to the tendency of resistor R6. However, heat transfer from the resistor R7 to the PTC thermistor R6 can be suppressed by the slit 50S formed on the substrate 50 .

In addition, in the present embodiment, the first semiconductor light emitting element L1 and the second semiconductor light emitting elements L2a, L2b and the switching circuit SC are mounted on the same substrate 50 . Therefore, compared with the case where these resistors are distributed and mounted on a plurality of substrates, the structure can be simplified.

(second embodiment)

Next, a second embodiment of the present invention will be described in detail with reference to FIG. 7 . In addition, the same reference numerals are assigned to the same or equivalent constituent elements as those of the first embodiment, unless otherwise specified, and overlapping descriptions will be omitted.

FIG. 7 is a diagram showing a circuit diagram of the vehicle headlamp in the present embodiment in the same manner as in FIG. 4 . As shown in FIG. 7, the circuit used in the vehicle headlamp of this embodiment is the same as that of the first embodiment shown in FIG. It is configured with the substrate 52 , which is different from the substrate used in the vehicle headlamp 1 of the first embodiment.

The substrate 51 is different from the substrate 50 in the first embodiment in that the first semiconductor light emitting element L1 and the second semiconductor light emitting elements L2a, L2b are not mounted on it. Also in this embodiment, a slit 51S is formed on the substrate 51 between at least one of the transistors TR1 , FT2 , and FT3 , which are semiconductor switches, and at least a part of the PTC thermistor R6 . In addition, although not shown in FIG. 7 , the slit 51S is also formed between at least a part of the PTC thermistor R6 and at least a part of the resistor R7 connected in series with the PTC thermistor R6 .

On the substrate 52, the first semiconductor light emitting element L1 and the second semiconductor light emitting elements L2a, L2b are mounted. That is, in this embodiment, the first semiconductor light emitting element L1 and the second semiconductor light emitting elements L2a, L2b are mounted on a substrate 52 different from the substrate 51 on which the switching circuit SC is mounted, and the first semiconductor light emitting element L1 and the second semiconductor light emitting element The semiconductor light emitting elements L2a, L2b are mounted on the same substrate.

According to the vehicle headlamp of this embodiment, the substrate 52 on which the first semiconductor light emitting element L1 and the second semiconductor light emitting elements L2a, L2b are mounted is a different substrate from the substrate 51 on which the switching circuit SC or the PTC thermistor R6 is mounted. Therefore, the substrate 51 can be separated from the first lamp LH or the second lamp LLa, LLb. Therefore, the degree of freedom in design of the vehicle headlamp can be improved. In addition, heat generated from the first semiconductor light emitting element L1 and the second semiconductor light emitting elements L2a, L2b can be suppressed from being transferred to the substrate 51 on which the switching circuit SC or the PTC thermistor R6 is mounted. Therefore, it is possible to suppress the influence of the heat generated from the first semiconductor light emitting element L1 and the second semiconductor light emitting elements L2a, L2b on the operation of the PTC thermistor R6.

In addition, in this embodiment, since the first semiconductor light emitting element L1 and the second semiconductor light emitting elements L2a, L2b are mounted on the same substrate, they are mounted on the same substrate as the first semiconductor light emitting element L1 and the second semiconductor light emitting elements L2a, L2b. Compared with the case of different substrates, the structure can be made simpler.

(third embodiment)

Next, a third embodiment of the present invention will be described in detail with reference to FIG. 8 . In addition, the same or equivalent structural elements as those of the second embodiment are given the same reference numerals and redundant descriptions are omitted, unless otherwise specified.

FIG. 8 is a diagram showing a circuit diagram of a vehicle headlamp in the present embodiment in the same manner as in FIG. 4 . As shown in FIG. 8 , the circuit used in the vehicle headlamp of this embodiment is the same as that of the second embodiment shown in FIG. 7 , but in the vehicle headlamp of this embodiment, as the first resistor The resistor R8 is not mounted on the substrate 51 but is mounted on the substrate 52, which is different from the substrate used in the vehicle headlamp of the second embodiment.

According to the vehicle headlamp of this embodiment, the first semiconductor light emitting element L1 and the resistor R8 are mounted on the same substrate 52 . As described in the first embodiment, when the current flows through the first semiconductor light emitting element L1, the first semiconductor light emitting element L1 generates heat, and when the current does not flow through the first semiconductor light emitting element L1, the current flows as the first semiconductor light emitting element L1. resistor R8 and resistor R8 heats up. Therefore, by mounting the first semiconductor light emitting element L1 and the resistor R8 on the same substrate 50 , it is possible to suppress a change in temperature of the substrate 52 on which the first semiconductor light emitting element L1 is mounted between high beam lighting and low beam lighting. Therefore, compared with the case where the resistor R8 is mounted on a substrate different from the substrate 52, it is possible to reduce the temperature of the substrate 52 shortly after the high beam is turned on, and the temperature of the substrate 52 immediately after switching from the low beam to the high beam. Difference. Therefore, the light emission of the first semiconductor light emitting element L1 can be further stabilized.

(fourth embodiment)

Next, a fourth embodiment of the present invention will be described in detail with reference to FIG. 9 . In addition, about the same or equivalent structural elements as those of the third embodiment, unless otherwise mentioned, the same reference numerals are assigned to omit overlapping descriptions.

FIG. 9 is a diagram showing a circuit diagram of a vehicle headlamp in the present embodiment in the same manner as in FIG. 4 . As shown in FIG. 9, the circuit used in the vehicle headlamp of this embodiment is the same as that of the third embodiment shown in FIG. 8, but in the vehicle headlamp of this embodiment, the third embodiment The substrate 52 is divided into two substrates, a substrate 53 and a substrate 54 , the first semiconductor light emitting element L1 and resistor R8 are mounted on the substrate 53 , and the second semiconductor light emitting elements L2a, L2b are mounted on the substrate 54 . That is, in this embodiment, the first semiconductor light emitting element L1 and the second semiconductor light emitting elements L2a, L2b are mounted on a substrate different from the substrate 51 on which the switching circuit SC is mounted, and the first semiconductor light emitting element L1 and the second semiconductor light emitting element The semiconductor light emitting elements L2a and L2b are mounted on different substrates from each other.

According to the vehicle headlamp of the present embodiment, the first semiconductor light emitting element L1 and the resistor R8 are mounted on the same substrate 51, so that the temperature of the substrate 51 on which the first semiconductor light emitting element L1 is mounted can be suppressed from decreasing when the high beam is turned on. The change when the light is turned on can make the light emission of the first semiconductor light emitting element L1 more stable.

Furthermore, since the first semiconductor light emitting element L1 and the second semiconductor light emitting elements L2a, L2b are mounted on different substrates, thermal interference between the first semiconductor light emitting element L1 and the second semiconductor light emitting elements L2a, L2b can be suppressed.

(fifth embodiment)

Next, a fifth embodiment of the present invention will be described in detail with reference to FIG. 10 . In addition, about the same or equivalent structural elements as those of the first embodiment, unless otherwise mentioned, the same reference numerals are assigned to omit overlapping descriptions.

FIG. 10 is a diagram showing a circuit diagram of the vehicle headlamp in the present embodiment in the same manner as in FIG. 4 . As shown in FIG. 10 , the vehicle headlamp of this embodiment differs from the vehicle headlamp 1 of the first embodiment in that it further includes a third semiconductor light emitting element L3 for emitting light to be a high beam. , the fourth semiconductor light emitting element L4a, L4b for emitting light that becomes the low beam, and the second PTC heat source arranged on the path of the current applied to the third semiconductor light emitting element L3 and the fourth semiconductor light emitting element L4a, L4b The PTC thermistor R9 of the sensitive resistor, the resistor R10 as the fourth resistor, and the resistor R11 as the third resistor. In addition, in this embodiment, the PTC thermistor R9, resistors R10, R11, third semiconductor light emitting element L3, fourth semiconductor light emitting element L4a, L4b are mounted on the substrate 50, which is different from that of the first embodiment. The substrate 50 is different.

One electrode of the PTC thermistor R9 is connected to the terminal LO, one electrode of the PTC thermistor R6 and one electrode of the resistor R2, and the other electrode of the PTC thermistor R9 is connected to one electrode of the resistor R10. The anode of the fourth semiconductor light emitting element L4b is connected to the other electrode of the resistor R10, the anode of the fourth semiconductor light emitting element L4b is connected to the cathode of the fourth semiconductor light emitting element L4a, and the fourth semiconductor light emitting element L4b is connected to the cathode of the fourth semiconductor light emitting element L4b. The anode of the three semiconductor light emitting elements L3. That is, the terminal LO, the PTC thermistor R9, the resistor R10, the fourth semiconductor light emitting element L4a, the fourth semiconductor light emitting element L4b, and the third semiconductor light emitting element L3 are connected in series. The drain of the transistor FT3 is connected to the cathode of the third semiconductor light emitting element L3. Therefore, the PTC thermistor R6, the resistor R7, the second semiconductor light emitting element L2a, the second semiconductor light emitting element L2b, and the first semiconductor light emitting element L1, and the PTC thermistor R9, the resistor R10, the first semiconductor light emitting element L4a, The fourth semiconductor light emitting element L4b and the third semiconductor light emitting element L3 are connected in parallel. In addition, one electrode of a resistor R11 as a third resistor is connected to the cathode of the fourth semiconductor light emitting element L4b and the anode of the third semiconductor light emitting element L3, and the other electrode of the resistor R11 is connected to the other electrode of the resistor R8 and the transistor FT2 the drain. That is, the third semiconductor light emitting element L3 and the resistor R11 are connected in parallel, the PTC thermistor R6, the resistor R7, the second semiconductor light emitting element L2b, the second semiconductor light emitting element L2b and the resistor R8, and the PTC thermistor R9, resistor R10, fourth semiconductor light emitting element L4a, fourth semiconductor light emitting element L4b, and resistor R11 are connected in parallel. In addition, in this embodiment, the magnitude of the resistance of the third semiconductor light emitting element L3 is substantially equal to the magnitude of resistance of the resistor R11.

As described in the first embodiment, the switching circuit SC switches the path of the current so that the current flows through one of the first semiconductor light emitting element L1 and the resistor R8 as the first resistor. By switching the current, the switching circuit SC switches the path of the current so that the current flows through one of the third semiconductor light emitting element L3 and the resistor R11 as the third resistor.

In addition, a slit 50Sa similar to the slit 50S of the first embodiment is formed on the substrate 50 between at least one of the transistor TR1 and the transistors FT2 and FT3 which are semiconductor switches, and at least a part of the PTC thermistor R6. . Furthermore, in the present embodiment, a slit 50Sb is formed on the substrate 50 between the transistor TR1 and at least one of the transistors FT2 and FT3 and at least a part of the PTC thermistor R9. In addition, the slit 50Sa is also formed between at least a part of the PTC thermistor R6 and at least a part of the resistor R7 connected in series to the RTC thermistor R6, and the slit 50Sb is also formed in the PTC thermistor R9. Between at least a part of and at least a part of the resistor R10 connected in series with the PTC thermistor R9. However, in FIG. 10 , the scene where the slits 50Sa and 50Sb are formed at these positions is omitted. In this embodiment, the slit 50Sa and the slit 50Sb are not connected to each other, but are different slits.

The vehicle headlamp having such a circuit according to the present embodiment is turned on as follows.

When the low beam is turned on, as in the vehicle headlamp 1 of the first embodiment, the current flowing from the terminal LO flows through the second semiconductor light emitting elements L2a, L2b via the PTC thermistor R6 and the resistor R7, And flow through resistor R8. Furthermore, in the present embodiment, when the low beam is turned on, the current flowing from the terminal LO flows through the fourth semiconductor light emitting elements L4a, L4b via the PTC thermistor R9 and the resistor R10 in parallel with the flow of the current. . At this time, the flow of current between the drain and the source of the transistor FT3 is suppressed, and a current flows between the drain and the source of the transistor FT2. Therefore, the current flowing through the fourth semiconductor light emitting elements L4a, L4b is suppressed from flowing to the third semiconductor light emitting element L3, and flows through the resistor R11. The current flowing through the resistors R8 and R11 flows through the ground GND via the transistor FT2.

Thus, the light emission of the first semiconductor light emitting element L1 and the third semiconductor light emitting element L3 is suppressed, and the second semiconductor light emitting elements L2a, L2b and the fourth semiconductor light emitting elements L4a, L4b emit light. In this way, the low beam is turned on.

When the high beam is turned on, as in the vehicle headlamp 1 of the first embodiment, the current flowing from the terminal LO flows through the second semiconductor light emitting elements L2a, L2b via the PTC thermistor R6 and the resistor R7, And flow through the first semiconductor light emitting element L1. Furthermore, in the present embodiment, when the high beams are turned on, the current flowing from the terminal LO flows through the fourth semiconductor light emitting elements L4a, L4b via the PTC thermistor R9 and the resistor R10 in parallel with the flow of the current. . At this time, the flow of current between the drain and the source of the transistor FT2 is suppressed, and a current flows between the drain and the source of the transistor FT3. Therefore, the current flowing through the fourth semiconductor light emitting element L4a, L4b is suppressed from flowing to the resistor R11, and flows through the third semiconductor light emitting element L3. The current flowing through the first semiconductor light emitting element L1 and the third semiconductor light emitting element L3 flows through the ground line GND via the transistor FT3.

Thus, the second semiconductor light emitting element L2a, L2b, and the fourth semiconductor light emitting element L4a, L4b emit light, and the first semiconductor light emitting element L1, and the third semiconductor light emitting element L3 emit light, thereby turning on the high beam.

According to the vehicle headlamp of this embodiment, the third semiconductor light emitting element L3 and the fourth semiconductor light emitting elements L4a, L4b are provided, so that the amount of light emitted per semiconductor light emitting element can be reduced. In addition, even in such a case, by the PTC thermistor R9 as the second PTC thermistor, the magnitude of the current flowing through the semiconductor light emitting element can be reduced, and the amount of light emitted from the semiconductor light emitting element can be adjusted, wherein the A current is applied to the semiconductor light emitting element from a current path in which the PTC thermistor R9 is arranged. Furthermore, the heat generated by semiconductor switches such as transistor TR1 or transistors FT2 and FT disposed on the same substrate as the PTC thermistor R9 is transmitted to the PTC thermistor R9, so even in the case of low ambient temperature, it is possible to PTC thermistor R9 works properly. Accordingly, it is possible to stably emit light from the semiconductor light emitting element to which a current is applied from the current path in which the PTC thermistor R9 is disposed.

In addition, in this embodiment, the slit 50Sb is formed in the board|substrate 50 between at least one of semiconductor switches, such as transistor TR1, transistor FT2, FT3, and at least a part of PTC thermistor R9. Therefore, it is possible to adjust the heat transferred from at least one of semiconductor switches such as the transistor TR1 and the transistors FT2 and FT3 to the PTC thermistor R9 through the slit 50Sb.

In addition, in the vehicle headlamp of the present embodiment, the slit 50Sa between the transistor TR1, transistors FT2, FT3 and other semiconductor switches and the PTC thermistor R6, and the gap between these semiconductor switches and the PTC thermistor R9 The slits 50Sb between them become different slits. Therefore, through the respective slits 50Sa and 50Sb, the heat transferred from semiconductor switches such as transistor TR1 and transistors FT2 and FT3 to the PTC thermistor R6 and the heat transferred from these semiconductor switches to the PTC thermistor R9 can be separately adjusted. .

In addition, in this embodiment, there is a resistor R11 as a third resistor connected in parallel with the third semiconductor light emitting element L3, and the switching circuit SC switches the path of the current so that the current flows through the third semiconductor light emitting element L3 and the resistor R11. party. Therefore, when the current does not flow in the third semiconductor light emitting element L3, the current flows through the resistor R11, and the load of other currents can be suppressed from changing when the third semiconductor light emitting element L3 emits light and when it does not emit light, and a more stable the light up. Furthermore, in this embodiment, the third semiconductor light emitting element L3 and the resistor R11 are mounted on the same substrate. When the current flows through the third semiconductor light emitting element L3, the third semiconductor light emitting element L3 generates heat, and when the current does not flow through the third semiconductor light emitting element L3 as described above, the current flows through the resistor R11, so the resistor R11 generates heat. Therefore, by mounting the third semiconductor light emitting element L3 and the resistor R11 on the same substrate 50 , it is possible to suppress a change in the temperature of the substrate 50 between when the high beam is turned on and when the high beam is turned off. Therefore, the light emission of the third semiconductor light emitting element L3 can be further stabilized.

In addition, in the vehicle headlamp of the present embodiment, the first semiconductor light emitting element L1, the second semiconductor light emitting elements L2a, L2b, the third semiconductor light emitting element L3, the fourth semiconductor light emitting element L4a, L4b, and the switching circuit SC are controlled. mounted on the same substrate. Therefore, compared with the case where these semiconductor light emitting elements and the switching circuit SC are mounted on different substrates, the structure can be simplified.

(sixth embodiment)

Next, a sixth embodiment of the present invention will be described in detail with reference to FIGS. 11 to 13 . In addition, about the same or equivalent structural elements as those of the fifth embodiment, unless otherwise mentioned, the same reference numerals are given and repeated descriptions are omitted.

FIG. 11 is a diagram showing a circuit diagram of a vehicle headlamp in the present embodiment in the same manner as in FIG. 4 . 12 is a plan view showing a substrate on which the switching circuit shown in FIG. 11 is mounted, and FIG. 13 is a plan view showing all the substrates in FIG. 11 . As shown in FIG. 11, the circuit used in the vehicle headlamp of this embodiment is the same as that of the fifth embodiment shown in FIG. 10, but as shown in FIGS. The substrate used in the vehicle headlight is different from the substrate used in the vehicle headlight of the fifth embodiment in that it is composed of a substrate 51 , substrates 52 a , 52 b , and substrates 53 a , 53 b .

The substrate 51 is different from the substrate 50 of the fifth embodiment in that the first semiconductor light emitting element L1, the second semiconductor light emitting elements L2a, L2b, the third semiconductor light emitting element L3, and the fourth semiconductor light emitting elements L4a, L4b are not mounted.

The first semiconductor light emitting element L1 is mounted on the substrate 53a, the second semiconductor light emitting element L2a, L2b is mounted on the substrate 54a, the third semiconductor light emitting element L3 is mounted on the substrate 53b, and the fourth semiconductor light emitting element L4a, L4b is mounted on the substrate 54b. . That is, in the present embodiment, the first semiconductor light emitting element L1, the second semiconductor light emitting element L2a, L2b, the third semiconductor light emitting element L3, and the fourth semiconductor light emitting element L4a, L4b are mounted on the side of the mounting switching circuit SC. On different substrates of the substrate 51, the first semiconductor light emitting element L1, the second semiconductor light emitting elements L2a and L2b, the third semiconductor light emitting element L3, and the fourth semiconductor light emitting elements L4a and L4b are respectively mounted on different substrates. In addition, the second semiconductor light emitting elements L2a and L2b are mounted on the same substrate 54a, and the fourth semiconductor light emitting elements L4a and L4b are mounted on the same substrate 54b.

In FIG. 12 , the substrate 51 is shown from one side of the substrate 51 . As shown in FIG. 12 , in this embodiment, the substrate 51 has a substantially quadrilateral shape. As shown in FIGS. , R10, R11 and other resistors. In addition, in the present embodiment, the substrate 50 is a substrate on which components are mounted on one surface, and these components are mounted on one surface.

In addition, like the first embodiment, the resistor shown as one in the circuit diagram shown in FIG. 12 may be composed of a plurality of elements. For example, the resistors R1, R7, R8, R10, and R11 are connected in series or in parallel through a plurality of resistor elements. And the composition is represented as a resistor on the circuit diagram. In addition, PTC thermistors R6 and R9 may be composed of a plurality of elements, but in this embodiment, an example in which each of PTC thermistors R6 and R9 are composed of four PTC thermistor elements connected in parallel is shown. In FIG. 12 , these plural elements are surrounded by dotted lines and given reference numerals.

In addition, a slit 51Sa is formed in the substrate 51 between at least one of the transistor TR1 and the transistors FT2 and FT3 which are semiconductor switches, and at least a part of the PTC thermistor R6 when the substrate 51 is viewed from above. Furthermore, a slit 51Sb is formed in the substrate 51 between at least one of the transistor TR1 , the transistors FT2 , and FT3 , and at least a part of the PTC thermistor R9 in plan view of the substrate 51 . In this embodiment, the slit 51Sa and the slit 51Sb are not connected to each other, but are different slits. In addition, in the present embodiment, the slit 51Sa is also formed between at least a part of the PTC thermistor R6 and at least a part of the resistor R7 connected in series with the PTC thermistor R6. In addition, the slit 51Sb is also formed between at least a part of the PTC thermistor R9 and at least a part of the resistor R10 connected in series with the PTC thermistor R9. However, the scene where the slits 51Sa and 51Sb are formed at these positions is omitted in FIG. 11 .

In addition, in the vehicle headlamp of the present embodiment, the first semiconductor light emitting element L1, the second semiconductor light emitting elements L2a and L2b, the third semiconductor light emitting element L3, the fourth semiconductor light emitting element L4a and L4b, and the switching circuit SC are mounted. on different substrates. Therefore, it is possible to suppress transfer of heat generated from the first semiconductor light emitting element L1, the second semiconductor light emitting element L2a, L2b, the third semiconductor light emitting element L3, and the fourth semiconductor light emitting element L4a, L4b to the mounted switching circuit SC or the PTC thermistor. The substrate 51 of the device R6, R9. Therefore, the influence of the heat generated from these semiconductor light emitting elements on the operation of the PTC thermistors R6 and R9 can be suppressed.

Furthermore, in the vehicle headlamp of the present embodiment, the first semiconductor light emitting element L1, the second semiconductor light emitting elements L2a and L2b, the third semiconductor light emitting element L3, and the fourth semiconductor light emitting elements L4a and L4b are all mounted on different the substrate. Therefore, the degree of freedom in design such as the design of the vehicle headlamp can be improved. In addition, it is possible to suppress transfer of heat generated from each semiconductor light emitting element to a substrate on which other semiconductor light emitting elements are mounted. In addition, the second semiconductor light emitting element L2a and the second semiconductor light emitting element L2b are mounted on the same substrate 54a, and the fourth semiconductor light emitting element L4a and the fourth semiconductor light emitting element L4b are mounted on the same substrate 54b. In addition, since the second semiconductor light emitting element L2a and the second semiconductor light emitting element L2b always emit light at the same time, there is no need to consider the mutual thermal influence too much, and because the fourth semiconductor light emitting element L4a and the fourth semiconductor light emitting element L4b always emit light simultaneously, there is no need to overthink Consider mutual thermal influences.

(seventh embodiment)

Next, a seventh embodiment of the present invention will be described in detail with reference to FIG. 14 . In addition, about the same or equivalent structural elements as those of the sixth embodiment, unless otherwise mentioned, the same reference numerals are assigned to omit overlapping descriptions.

FIG. 14 is a diagram showing a circuit diagram of the vehicle headlamp in the present embodiment in the same manner as in FIG. 4 . As shown in FIG. 14, the circuit used in the vehicle headlamp of this embodiment is the same as that of the sixth embodiment shown in FIG. 11, but in the vehicle headlamp of this embodiment, the sixth embodiment The substrate 53a of the first embodiment is formed integrally with the substrate 54a to form the substrate 52a, and the substrate 53b of the sixth embodiment is formed integrally with the substrate 54b to form the substrate 52b. Furthermore, in this embodiment, the resistor R8 as the first resistor is not mounted on the substrate 51 but is mounted on the substrate 52 a, and the resistor R11 as the third resistor is not mounted on the substrate 51 but is mounted on the substrate 52 b.

According to the vehicle headlamp of this embodiment, the first semiconductor light emitting element L1 and the resistor R8 are mounted on the same substrate 52a, and the third semiconductor light emitting element L3 and the resistor R11 are mounted on the same substrate 52b. As described in the fifth embodiment, when the current flows through the first semiconductor light emitting element L1, the first semiconductor light emitting element L1 emits light, and when the current does not flow through the first semiconductor light emitting element L1, the current flows through the resistor R8 as the first resistor. And the resistor R8 generates heat. In addition, as described in the fifth embodiment, when the current flows through the third semiconductor light emitting element L3, the third semiconductor light emitting element L3 generates heat, and when the current does not flow through the third semiconductor light emitting element L3, the current flows through the third resistor. resistor R11 and resistor R11 generates heat. Therefore, by mounting the first semiconductor light emitting element L1 and the resistor R8 on the same substrate 52a, it is possible to suppress a change in the temperature of the substrate 52a on which the first semiconductor light emitting element L1 is mounted when the high beam is turned on and when the low beam is turned on. By mounting the third semiconductor light emitting element L3 and the resistor R11 on the same substrate 52b, it is possible to suppress a change in temperature of the substrate 52b on which the third semiconductor light emitting element L3 is mounted between high beam lighting and low beam lighting. Therefore, compared with the case where the resistor R8 is mounted on a substrate different from the substrate 52a or the resistor R11 is mounted on a substrate different from the substrate 52b, it is possible to reduce the number of substrates 52a, 52b after a short period of time after the high beam is turned on. The difference between the temperature of and the temperature of the substrate 52a and the substrate 52b just after switching from the low beam to the high beam. Therefore, the light emission of the first semiconductor light emitting element L1 and the third semiconductor light emitting element L3 can be further stabilized.

(eighth embodiment)

Next, an eighth embodiment of the present invention will be described in detail with reference to FIGS. 15 and 17 . In addition, about the same or equivalent structural elements as those of the sixth embodiment, unless otherwise mentioned, the same reference numerals are assigned to omit overlapping descriptions.

FIG. 15 is a diagram showing a circuit diagram of a vehicle headlamp in the present embodiment in the same manner as in FIG. 4 . 16 is a plan view of the substrate on which the switching circuit of FIG. 15 is mounted, and FIG. 17 is a plan view showing all the substrates of FIG. 15 . As shown in FIG. 15, the circuit used in the vehicle headlamp of this embodiment is the same as that of the sixth embodiment shown in FIG. 11. As shown in FIGS. The substrates used in the headlamp are the substrate 51 , the substrate 53 a , the substrate 54 a , the substrate 53 b , and the substrate 54 b as in the sixth embodiment. However, in the vehicle headlamp of the present embodiment, the resistor R8 as the first resistor is mounted on the substrate 53a instead of the substrate 51, and the resistor R11 as the third resistor is mounted on the substrate 53b instead of the substrate 51.

Compared with the vehicle headlamp of the sixth embodiment in which the resistor R8 is mounted on a substrate different from the substrate 53a or the resistor R11 is mounted on a substrate different from the substrate 53b, it is possible to reduce the time elapsed after the high beam is turned on. The difference between the temperature of the substrate 53a and the substrate 53b and the temperature of the substrate 53a and the substrate 53b just after switching from the low beam to the high beam. Therefore, the light emission of the first semiconductor light emitting element L1 and the third semiconductor light emitting element L3 can be further stabilized.

As mentioned above, although this invention was demonstrated taking 1st Embodiment - 8th Embodiment as an example, this invention is not limited to this.

For example, in the above embodiments, the number of the first semiconductor light emitting element L1 and the third semiconductor light emitting element L3 is represented as one, but the number of these light emitting elements is not particularly limited. In addition, the number of the second semiconductor light emitting element and the fourth semiconductor light emitting element are respectively regarded as two and set as the second semiconductor light emitting element L2a and L2b, and the fourth semiconductor light emitting element L4a and L4b, but the number of these light emitting elements can be respectively One is not particularly limited.

In addition, the PTC thermistors R6 and R9 can be composed of one component, and the resistors R1, R2, R3, R4, R5, R7, R8, R10, and R11 can be composed of one component or multiple components. .

In addition, the substrate 52 of the second embodiment may be divided into two substrates, one of which mounts the first semiconductor light emitting element L1, and the other mounts the second semiconductor light emitting elements L2a, L2b. In addition, in the sixth embodiment, the substrate 53a and the substrate 54 may be integrally formed as one substrate, and the substrate 53b and the substrate 54b may be integrally formed as one substrate. In this case, the substrate 53a and the substrate 54a are integrated, and the substrate 53b and the substrate 54b are integrated. In addition, the substrate 52a and the substrate 52b of the seventh embodiment may be integrated into one substrate.

In addition, in the above-mentioned embodiment, the description has been made using the bipolar transistor TR1 and the field effect transistors FT2 and FT3 as the semiconductor switch, but the form of the semiconductor switch is not limited to this.

In addition, in the above-mentioned embodiment, the first semiconductor light emitting element L1, the second semiconductor light emitting element L2a and L2b are connected in series, and the third semiconductor light emitting element L3, the fourth semiconductor light emitting element L4a and L4b are connected in series. illustrate. However, in the present utility model, the first semiconductor light emitting element L1, the second semiconductor light emitting element L2a and L2b may also be connected in parallel, and the PTC thermistor R6 is arranged on the first semiconductor light emitting element L1 and the second semiconductor light emitting element. At least one of the light emitting elements L2a and L2b is on the path of the applied current. Similarly, in the present utility model, it can also be set that the third semiconductor light emitting element L3 and the fourth semiconductor light emitting element L4a, L4b are connected in parallel, and the PTC thermistor R9 is arranged opposite to the third semiconductor light emitting element L3 and the fourth semiconductor light emitting element. The path of the current applied to at least one of the light emitting elements L4a, L4b.

In addition, in the above-mentioned embodiment, an example was shown in which a slit 50S or a slit is formed on the substrate 50 between at least one of the transistor TR1 and the transistors FT2 and FT3 as semiconductor switches, and at least a part of the PTC thermistor R6. An example of the slit 51Sa; or an example in which the slit 51Sb is formed in the substrate 50 between at least one of the transistor TR1 and the transistors FT2 and FT3 and at least a part of the PTC thermistor R9. However, the slit formed in the substrate is not essential. Only when a slit is formed on the substrate between at least one of the semiconductor switches and at least a part of the PTC thermistor is it possible to adjust the heat transferred from the semiconductor switch to the PTC thermistor, which is preferable.

In addition, in the above embodiment, the resistor R8 as the first resistor connected in parallel to the first semiconductor light emitting element L1 or the resistor R11 as the third resistor connected in parallel to the third semiconductor light emitting element L3 are provided. But these resistors are not necessary structures.

Moreover, in the said embodiment, the resistance R7 which is the 2nd resistance connected in series with the PTC thermistor R6, or the resistance R10 which is the 4th resistance connected in series with the PTC thermistor R9 is provided. But these resistors are not required structures.

In addition, in the above-mentioned embodiment, the parabolic lamp was described as an example, but the lamp is not particularly limited to the parabolic.

According to the present invention, there is provided a vehicle headlamp which can be turned on stably, and can be used in the field of vehicle headlamps such as motorcycles and automobiles.

Claims (19)

1. A vehicle headlamp, characterized in that it has: a first semiconductor light emitting element, which emits light that becomes high beam; a second semiconductor light emitting element that emits light that becomes low beam; a PTC thermistor disposed on a path of current applied to at least one of the first semiconductor light emitting element and the second semiconductor light emitting element; and a switching circuit having more than one semiconductor switch, and switching the lighting and extinguishing of the first semiconductor light-emitting element, At least one of the semiconductor switches and the PTC thermistor are mounted on the same substrate. 2. The vehicle headlamp according to claim 1, wherein: A slit is formed on the substrate between at least one of the semiconductor light emitting elements and at least a part of the PTC thermistor. 3. The vehicle headlamp according to claim 1, wherein: further has a first resistor connected in parallel with the first semiconductor light emitting element, The switching circuit switches the path of the current so that the current flows through one of the first semiconductor light emitting element and the first resistor. 4. The vehicle headlamp according to claim 3, wherein: The first semiconductor light emitting element and the first resistor are mounted on the same substrate. 5. The vehicle headlamp according to any one of claims 1 to 4, wherein: The first semiconductor light emitting element and the second semiconductor light emitting element are connected in series. 6. The vehicle headlamp according to any one of claims 1 to 4, wherein: It further has a second resistor connected in series to the PTC thermistor. 7. The vehicle headlamp according to claim 1, further comprising: a third semiconductor light emitting element, which emits light that becomes high beam; a fourth semiconductor light emitting element that emits light that becomes low beam; and a second PTC thermistor disposed on a path of current applied to at least one of the third semiconductor light emitting element and the fourth semiconductor light emitting element, the switching circuit switches the lighting and extinguishing of the third semiconductor light emitting element, At least one of the semiconductor switches and the second PTC thermistor are mounted on the same substrate. 8. The vehicle headlamp according to claim 7, wherein: A slit is formed on the substrate between at least one of the semiconductor switches and at least a part of the second PTC thermistor. 9. The vehicle headlamp according to claim 8, wherein: The slit between the semiconductor switch and the PTC thermistor is a different slit from the slit between the semiconductor switch and the second PTC thermistor. 10. The vehicle headlamp according to any one of claims 7 to 9, wherein: It also has a third resistor connected in parallel with the third semiconductor light emitting element, The switching circuit switches the path of the current so that the current flows through one of the third semiconductor light emitting element and the third resistor. 11. The vehicle headlamp according to claim 10, wherein: The third semiconductor light emitting element and the third resistor are mounted on the same substrate. 12. The vehicle headlamp according to claim 1, wherein: The first semiconductor light emitting element, the second semiconductor light emitting element, and the switching circuit are mounted on the same substrate. 13. The vehicle headlamp according to claim 1, wherein: The first semiconductor light emitting element and the second semiconductor light emitting element are mounted on a substrate different from the substrate on which the switching circuit is mounted. 14. The vehicle headlamp according to claim 13, wherein: The first semiconductor light emitting element and the second semiconductor light emitting element are mounted on the same substrate. 15. The vehicle headlamp according to claim 13, wherein: The first semiconductor light emitting element and the second semiconductor light emitting element are mounted on different substrates. 16. The vehicle headlamp according to claim 7, wherein: The first semiconductor light emitting element, the second semiconductor light emitting element, the third semiconductor light emitting element, the fourth semiconductor light emitting element, and the switching circuit are mounted on the same substrate. 17. The vehicle headlamp according to claim 7, wherein: The first semiconductor light emitting element, the second semiconductor light emitting element, the third semiconductor light emitting element, and the fourth semiconductor light emitting element are mounted on a different substrate from the switching circuit. 18. The vehicle headlamp according to claim 17, wherein: The first semiconductor light emitting element and the second semiconductor light emitting element are mounted on the same substrate, The third semiconductor light emitting element and the fourth semiconductor light emitting element are mounted on the same substrate, The first semiconductor light emitting element and the second semiconductor light emitting element, and the third semiconductor light emitting element and the fourth semiconductor light emitting element are mounted on different substrates. 19. The vehicle headlamp according to claim 17, wherein: The first semiconductor light emitting element, the second semiconductor light emitting element, the third semiconductor light emitting element, and the fourth semiconductor light emitting element are all mounted on different substrates.