JP6904203B2 - Vehicle headlights - Google Patents

Description

The present invention relates to vehicle headlights.

A vehicle headlight having a light source, a reflector that reflects light from the light source, and a lens that emits light reflected by the reflector to an irradiation region in front of the vehicle is known (for example, a patent). Reference 1). In such vehicle headlights, the light source generates light to generate heat, which raises the temperature inside the lighting chamber. In order to suppress such a temperature rise, a lighting circuit that adjusts the illuminance of the light generated by the light source according to the temperature in the lighting chamber is provided.

Jitsufuku No. 6-10562 Gazette

In the above-mentioned vehicle headlights, the temperature in the lighting chamber is more likely to rise when the light source is turned on in an environment where sunlight is irradiated, for example, in the daytime in fine weather than at night. Therefore, when the light source is turned on in such an environment irradiated with sunlight, it is required to control the illuminance of the light generated by the light source to be lower than that at night.

However, in an environment where a large amount of sunlight is generally irradiated, the frequency of turning on the light source tends to be low. Therefore, the temperature in the lighting chamber may not rise depending on the timing at which the light source is turned on. When the light source is turned on when the temperature of the lighting chamber is not rising, it becomes difficult to adjust the illuminance of the light in the lighting circuit.

The present invention has been made in view of the above, and an object of the present invention is to provide a vehicle headlight capable of appropriately adjusting the illuminance of light generated by a light source in an environment irradiated with sunlight.

The vehicle headlight according to the present invention includes a light source, a reflector that reflects light from the light source, an incident surface on which the light reflected by the reflector is incident, and the light incident on the incident surface. It has a lens having an exit surface that emits light to a front irradiation region, a temperature sensor that detects temperature, and an illuminance control unit that adjusts the illuminance of light from the light source based on the detection result of the temperature sensor. It is provided with a lighting circuit in which the temperature sensor is arranged at a position where sunlight incident from the incident surface of the lens and emitted from the incident surface is irradiated.

Further, the temperature sensor may be arranged behind and below the lens in the vehicle-mounted state.

Further, the light source, the reflector, and a holding member for holding the lens are provided, the holding member has an opening behind and below the lens in the vehicle-mounted state, and the lighting circuit is the temperature sensor. May be arranged at a position exposed to the opening.

Further, the lighting circuit may have a storage unit that stores the temperature change when the sunlight is applied to the temperature sensor and the target value of the illuminance of the light generated by the light source in association with each other.

According to the present invention, it is possible to provide a vehicle headlight capable of appropriately adjusting the illuminance of light generated by a light source in an environment irradiated with sunlight.

FIG. 1 is a cross-sectional view showing an example of a vehicle headlight according to the first embodiment. FIG. 2 is a functional block diagram showing an example of a lighting circuit. FIG. 3 is a graph showing an example of correlation data.

Hereinafter, embodiments of the vehicle headlights according to the present invention will be described with reference to the drawings. The present invention is not limited to this embodiment. In addition, the components in the following embodiments include those that can be easily replaced by those skilled in the art, or those that are substantially the same. In the following description, each of the front-rear, up-down, and left-right directions is the direction in which the vehicle headlight is mounted on the vehicle, and indicates the direction when the traveling direction of the vehicle is viewed from the driver's seat. .. In this embodiment, it is assumed that the vertical direction is parallel to the vertical direction and the horizontal direction is the horizontal direction.

FIG. 1 is a diagram showing an example of a vehicle headlight 100 according to the first embodiment. As shown in FIG. 1, the vehicle headlight 100 includes a light source 10, a reflector 20, a lens 30, a holding member 40, and a circuit board 50. The light source 10, the reflector 20, the lens 30, the holding member 40, and the circuit board 50 form a so-called projector-type lamp unit.

The vehicle headlights 100 are attached to the left side and the right side of the front part of the vehicle, respectively. When mounted on a vehicle, the vehicle headlight 100 is housed in a lamp chamber 70 formed by a lamp housing (not shown) and a lamp lens (for example, a transparent outer lens), and an optical axis adjusting mechanism (not shown). Connected to. The optical axis adjusting mechanism can adjust the optical axis in the vertical direction and the horizontal direction in the vehicle headlight 100.

In addition to the lamp unit, for example, a clearance lamp unit, a turn signal lamp unit, a daytime running lamp unit, and the like may be arranged in the lamp chamber 70. Further, an inner panel (not shown), an inner housing (not shown), an inner lens (not shown), or the like may be arranged in the light chamber 70.

In the present embodiment, the light source 10 is a semiconductor type light source such as an LED, an OEL, or an OLED (organic EL). The light source 10 has a light emitting surface 11. The light source 10 emits light so that the light emitting surface 11 forms a Lambersian distribution. When the vehicle headlight 100 is attached to the vehicle, the light emitting surface 11 is directed upward, for example, and is arranged parallel to the horizontal plane.

The light source 10 is fixed to the light source fixing portion 42 of the holding member 40. The light source fixing portion 42 is connected to the heat sink 43. The heat sink 43 is provided with fins (not shown). Therefore, the heat generated in the light source 10 which is a semiconductor type light source is discharged from the light source fixing portion 42 to the outside through the heat sink 43. The light source fixing portion 42 and the heat sink 43 may be integrally formed as a heat sink.

The reflector 20 reflects the light from the light source 10 toward the lens 30. The reflector 20 is arranged above the light source 10 and is formed by using a material having high heat resistance and light impermeability, such as a resin member. The reflector 20 is fixed to the holding member 40 by a fixing member such as a screw.

The reflector 20 has a hollow shape in which the front side portion and the lower side portion are open, and the rear side portion, the upper portion, and the left and right side portions are closed. A first reflecting surface 21 and a second reflecting surface 22 are formed on the inner surface of the reflector 20. The first reflecting surface 21 and the second reflecting surface 22 reflect the light from the light source 10 toward the lens 30.

The first reflecting surface 21 and the second reflecting surface 22 are a spheroidal surface or a free curved surface based on the spheroidal surface. The first reflecting surface 21 and the second reflecting surface 22 have a first focus F1, a second focus F2, and an optical axis (not shown) connecting the first focus F1 and the second focus F2. The first focal point F1 is arranged at or near the center of the light emitting surface 11 of the light source 10. The second focal point F2 is arranged at a position overlapping the focal point of the lens 30 described later.

Further, the movable shade 6 is made of a member capable of blocking light from the light source 10, such as a metal plate. The movable shade 6 is arranged between the light source 10 and the lens 30. The movable shade 6 is connected to a drive unit (not shown), and can move between, for example, a first position that blocks a part of the light reflected by the reflector 20 and a second position that does not block the light. It has become.

The lens 30 is arranged in front of the vehicle with respect to the reflector 20. The lens 30 is supported by, for example, the lens holder 41. The lens 30 has a focal point (not shown) and an optical axis AX. The optical axis AX of the lens 30 coincides with or substantially coincides with the optical axis of the reflector 20. The lens 30 irradiates the front of the vehicle with the reflected light from the first reflecting surface 21.

The heat sink 43 dissipates heat generated by the light source 10 to the outside. The heat sink 43 fixes the light source 10, the reflector 20, the lens holder 41, and the like. The heat sink 43 can be manufactured by using, for example, mold molding or the like.

The holding member 40 has a lens holder 41, a light source fixing portion 42, and a heat sink 43. The lens holder 41 supports the outer circumference of the lens 30. The lens holder 41 has an opening 41a at the bottom. The opening 41a is provided so as to penetrate the lens holder 41 in the vertical direction. The light chamber 70 is arranged so as to communicate with the outside by the opening 41a. As shown in FIG. 1, for example, the opening 41a is arranged at a position where sunlight L incident from the emitting surface 32 of the lens 30 and emitted from the incident surface 31 passes through.

The circuit board 50 has a temperature sensor 51 and a lighting circuit 52. The circuit board 50 is arranged below the heat sink 43 in a vehicle-mounted state, and is supported by, for example, a part of the heat sink 43. For example, by mounting the temperature sensor 51 on the circuit board 50, the position of the temperature sensor 51 is stably maintained regardless of the vibration of the vehicle or the like.

FIG. 2 is a functional block diagram showing an example of the lighting circuit 52. The lighting circuit 52 shown in FIG. 2 controls an operation related to lighting of the light source 10. The lighting circuit 52 includes an input unit 53, a control unit 54, a storage unit 55, and an output unit 56. The input unit 53, the control unit 54, the storage unit 55, and the output unit 56 are connected via, for example, a bus line 57 or the like.

A command signal or the like for the lighting circuit 52 is input to the input unit 53. For example, the input unit 53 receives a signal instructing the light source 10 to be turned on or off. Further, the input unit 53 inputs the detection result of the temperature sensor 51.

The control unit 54 includes a lighting control unit 58 and an illuminance control unit 59. The lighting control unit 58 controls switching between lighting and extinguishing of the light source 10. The illuminance control unit 59 adjusts the target value of the illuminance of the light generated by the light source 10 by adjusting the current value supplied to the light source 10 based on the detection result by the temperature sensor 51 when the light source 10 is turned on.

The storage unit 55 stores programs and data for performing various operations in the lighting circuit 52. The storage unit 55 stores, for example, correlation data 60 showing the correlation between the detection result of the temperature sensor 51 and the target value of the illuminance of the light generated by the light source 10. In the present embodiment, as the target value of the illuminance of the light generated by the light source 10, for example, the target value of the current supplied to the light source 10 can be used. FIG. 3 is a graph showing an example of the correlation data 60. As shown in FIG. 3, the horizontal axis of the graph shows the temperature which is the detection result of the temperature sensor 51, and the vertical axis shows the target value of the current supplied to the light source 10.

As shown in FIG. 3, the correlation data 60 is a straight line showing the relationship between the temperature, which is the detection result of the temperature sensor 51, and the target value of the current supplied to the light source 10. In the correlation data 60, when the detection result of the temperature sensor 51 is the first temperature T1, the target value of the current is the first current value L1. Further, in the correlation data 60, when the detection result of the temperature sensor 51 is the second temperature T2 which is larger than the first temperature T1, the target value of the current is the second current value L2 which is lower than the first current value L1. Further, in the correlation data 60, as the detection result of the temperature sensor 51 increases from the first temperature T1 to the second temperature T2, the target value of the current increases from the first current value L1 to the second current value L2. It becomes smaller. The correlation data 60 is not limited to the above, and may exhibit other characteristics.

In the vehicle headlight 100 configured as described above, for example, when the lighting switch provided in the vehicle is switched on, a signal indicating that the lighting switch is turned on is input to the input unit 53. The lighting control unit 58 supplies a current to the light source 10 based on the input result to light the light source 10.

When the light source 10 is turned on, light is emitted from the light emitting surface 11 and reflected toward the lens 30 by the first reflecting surface 21 and the second reflecting surface 22 of the reflector 20. The light reflected by the reflector 20 is incident on the incident surface 31, passes through the inside of the lens 30, and is emitted from the emitting surface 32.

Further, in the lighting circuit 52, the illuminance of the light source 10 is adjusted according to the detection result of the temperature sensor 51. In this case, assuming that the detection result of the temperature sensor 51 is, for example, the first temperature T1, the illuminance control unit 59 sets the current value supplied to the light source 10 to the first current value L1 corresponding to the first temperature T1. Adjust so that

The vehicle headlight 100 may be exposed to sunlight L. As shown in FIG. 1, the sunlight L is incident on the lens 30 from, for example, the emitting surface 32, and is emitted rearward and downward from the incident surface 31. The sunlight L emitted from the incident surface 31 passes through the opening 41a in a condensed state and is irradiated to the temperature sensor 51 of the circuit board 50. The temperature sensor 51 detects the condensed heat of the sunlight L. Therefore, the detection result of the temperature sensor 51 gradually becomes a temperature higher than the first temperature T1 (for example, the second temperature T2).

The illuminance control unit 59 adjusts the current value supplied to the light source 10 according to the detection result of the temperature sensor 51. For example, when the detection result of the temperature sensor 51 rises from the first temperature T1 to the second temperature T2 due to the condensed heat of the sunlight L, the illuminance control unit 59 sets the target value of the current supplied to the light source 10 to the second temperature. The second current value L2 corresponding to the temperature T2 is adjusted. As a result, the illuminance of the light generated by the light source 10 decreases from the first current value L1 to the second current value L2.

In the above-mentioned vehicle headlight 100, the temperature in the lighting chamber when the light source 10 is turned on is more likely to rise in an environment where sunlight is irradiated, for example, in the daytime in fine weather than at night. Therefore, when the light source 10 is turned on in such an environment where the sunlight L is irradiated, it is required to control the illuminance of the light generated by the light source 10 to be lower than that at night.

On the other hand, in the vehicle headlight 100 according to the present embodiment, the light source 10, the reflector 20 that reflects the light from the light source 10, and the incident surface 31 on which the light reflected by the reflector 20 is incident are incident. The illuminance of the light from the light source 10 based on the lens 30 having an exit surface 32 that emits the light incident on the surface 31 to the irradiation region in front of the vehicle, the temperature sensor 51 that detects the temperature, and the detection result by the temperature sensor 51. It is provided with an illuminance control unit 59 for adjusting the light intensity control unit 59, and a lighting circuit 52 in which a temperature sensor 51 is arranged at a position where sunlight incident from the exit surface 32 of the lens 30 and emitted from the incident surface 31 is irradiated. ..

According to this configuration, in an environment where the sunlight L is irradiated, the sunlight L that is incident on the lens 30 from the emitting surface 32 and is emitted rearward and downward from the incident surface 31 is condensed. The temperature sensor 51 of the circuit board 50 is irradiated through the opening 41a. As a result, the temperature sensor 51 can detect the condensed heat of the sunlight L, so that the illuminance of the light generated by the light source 10 can be adjusted to be low without using a separate illuminance sensor or the like.

Further, in the vehicle headlight 100 according to the present embodiment, since the temperature sensor 51 is arranged behind and below the lens 30 in the vehicle-mounted state, sunlight L is incident from the exit surface 32 and is incident surface 31. The temperature sensor 51 can be arranged in the traveling direction of the sunlight L when the light is emitted from the inside of the light chamber 70. As a result, the temperature sensor 51 can be efficiently irradiated with the sunlight L.

Further, the vehicle headlight 100 according to the present embodiment has a holding member 40 for holding the light source 10, the reflector 20, and the lens 30, and the holding member 40 opens behind and below the lens 30 in the vehicle-mounted state. The circuit board 50 has a portion 41a, and the circuit board 50 is arranged at a position where the temperature sensor 51 is exposed to the opening 41a. As a result, when the circuit board 50 is arranged outside the light chamber 70, the temperature sensor 51 can be arranged in the traveling direction of the sunlight L. As a result, the temperature sensor 51 can be efficiently irradiated with the sunlight L.

Further, in the vehicle headlight 100 according to the present embodiment, the lighting circuit 52 associates the temperature change when the sunlight L is applied to the temperature sensor 51 with the target value of the illuminance of the light generated by the light source 10. It has a storage unit 55 that stores the correlation data 60. As a result, the illuminance of the light source 10 can be changed efficiently.

The technical scope of the present invention is not limited to the above-described embodiment, and modifications can be made as appropriate without departing from the spirit of the present invention. For example, in the above embodiment, the configuration in which the circuit board 50 is arranged outside the light chamber 70 has been described as an example, but the present invention is not limited to this, and the circuit board 50 is arranged inside the light chamber 70. It may have a different configuration.

L Solar AX Optical axis 6 Movable shade 10 Light source 11 Light source 11 Light source 20 Reflector 21 First reflection surface 22 Second reflection surface 30 Lens 31 Incident surface 32 Exit surface 40 Holding member 41 Lens holder 41a Opening 42 Light source fixing part 43 Heat sink 50 Circuit board 51 Temperature sensor 52 Lighting circuit 53 Input unit 54 Control unit 55 Storage unit 56 Output unit 57 Bus line 58 Lighting control unit 59 Illuminance control unit 60 Correlation data 70 Light room 100 Vehicle headlight

Claims (4)

Light source and
A reflector that reflects light from the light source,
A lens having an incident surface on which the light reflected by the reflector is incident, and an emitting surface that emits the light incident on the incident surface to an irradiation region in front of the vehicle.
It has a temperature sensor that detects the temperature and an illuminance control unit that adjusts the illuminance of light from the light source based on the detection result of the temperature sensor. A vehicle headlight including a lighting circuit in which the temperature sensor is arranged at a position where the sunlight is irradiated. The vehicle headlight according to claim 1, wherein the temperature sensor is arranged behind and below the lens in the vehicle-mounted state. It has a holding member that holds the light source, the reflector, and the lens.
The holding member has an opening behind and below the lens when mounted on the vehicle.
The vehicle headlight according to claim 1 or 2, wherein the lighting circuit is arranged at a position where the temperature sensor is exposed to the opening. The vehicle according to claim 2, wherein the lighting circuit has a storage unit that stores a temperature change when the temperature sensor is irradiated with sunlight and a target value of the illuminance of the light generated by the light source. Headlight for use.

Images