Vehicle headlight

Abstract

Provided is a vehicle headlight which can remove mist adhering to an outer lens without using a heater. A vehicle headlight includes: a housing; an outer lens attached to the housing to form a lamp chamber between the outer lens and the housing; a lamp unit configured to emit visible light transmitted through the visible light transmission region of the outer lens, the lamp unit being disposed in the lamp chamber; a light detection device configured to emit infrared light transmitted through the infrared light transmission region of the outer lens, the light detection device being disposed in the lamp chamber; and an infrared light control unit configured to control the infrared light emitted from the light detection device such that the infrared light emitted from the light detection device is irradiated toward a visible light transmission region of the outer lens.

Description

Technical Field

[0001] The present disclosure relates to vehicle headlights. Background Art

[0002] There is a known vehicle lamp in which a wire heater is provided in a lamp chamber formed between a housing and an outer lens attached to the housing to remove fogging attached to an outer lens (for example, see Patent Document 1).

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2008-21601 Summary of the invention

[0004] However, the vehicle lamp described in Patent Document 1 has a problem in that the interior of the lamp chamber reaches a higher temperature than necessary due to the wire heater.

[0005] The present disclosure is proposed to solve such a problem, and an object of the present disclosure is to provide a vehicle headlamp which can remove mist attached to an outer lens without using a heater.

[0006] A vehicle headlamp according to the present disclosure includes: a shell; an outer lens attached to the shell to form a lamp chamber between the outer lens and the shell; a lamp unit configured to emit visible light transmitted through a visible light transmission area of ​​the outer lens, the lamp unit being disposed in the lamp chamber; a light detection device configured to emit infrared light transmitted through an infrared light transmission area of ​​the outer lens, the light detection device being disposed in the lamp chamber; and an infrared light control unit configured to control the infrared light emitted from the light detection device so that the infrared light emitted from the light detection device is irradiated toward the visible light transmission area of ​​the outer lens.

[0007] With such a configuration, fog attached to the outer lens can be removed without using a heater.

[0008] This can be achieved because an infrared light control unit (e.g., a light deflection element and a light deflection element driving mechanism) is provided to control the infrared light emitted from the light detection device so that the infrared light emitted from the light detection device is irradiated toward the visible light transmission area of ​​the outer lens.

[0009] In the above-mentioned vehicle headlights, the infrared light control unit may include a light deflection element and a light deflection element driving mechanism, the light deflection element may be configured to deflect the infrared light so that the deflected infrared light is irradiated toward the visible light transmission area of ​​the outer lens, the infrared light is emitted from the light detection device and incident on the light deflection element, and the light deflection element driving mechanism may enable the light deflection element to be set at an infrared light incident position or an infrared light non-incident position, the infrared light incident position is located in the optical path of the infrared light emitted from the light detection device, and the infrared light non-incident position is located outside the optical path of the infrared light emitted from the light detection device.

[0010] In the above-mentioned vehicle headlights, when the light deflection element is set at an infrared light non-incident position, the light detection device can emit infrared light by applying a first driving voltage, and when the light deflection element is set at an infrared light incident position, the light detection device can emit infrared light by applying a second driving voltage higher than the first driving voltage.

[0011] In the above-mentioned vehicle headlight, the vehicle headlight may further include a fog detection unit, which is configured to perform a fog detection process for detecting fog attached to the outer lens, wherein when fog is detected, the light deflection element driving mechanism can set the light deflection element at an infrared light incident position, and when no fog is detected, the light deflection element driving mechanism can set the light deflection element at an infrared light non-incident position.

[0012] In the above-mentioned vehicle headlight, the wavelength of the infrared light may be a wavelength selected from the range of 895 nm to 960 nm and the range of 1350 nm to 1550 nm.

[0013] In the above-mentioned vehicle headlight, the light detection device may include a semiconductor light emitting element configured to emit infrared light, and the semiconductor light emitting element may be any one of a stripe LD, a VCSEL, and a PCSEL.

[0014] In the above-mentioned vehicle headlight, the vehicle headlight may further include a bracket to which the lamp unit is attached; and an optical axis adjustment mechanism configured to adjust the optical axis of the lamp unit by tilting the bracket, wherein the light detection device may be attached to the bracket.

[0015] The present disclosure may provide a vehicle headlamp which can remove mist attached to an outer lens without using a heater.

[0016] The above and other objects, features and advantages of the present disclosure will be more fully understood from the detailed description and accompanying drawings given below. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic configuration diagram of a vehicle lamp system 1 including a vehicle headlight 10 according to an embodiment;

[0018] Figure 2 is a front view of a vehicle V equipped with the vehicle lighting system 1;

[0019] Figure 3A It is along Figure 2 A cross-sectional view taken at AA in FIG.

[0020] Figure 3B It is along Figure 2 A cross-sectional view taken at AA in FIG.

[0021] Figure 4 1 shows a low-beam light distribution pattern P formed on a virtual vertical screen facing the front surface of the vehicle (set at a position about 25 m in front of the front surface of the vehicle). Lo An example of;

[0022] Figure 5A is a schematic configuration diagram of the light detection device 30;

[0023] Figure 5B It is along Figure 5A A cross-sectional view taken from BB in FIG.

[0024] Figure 5C It is along Figure 5A A cross-sectional view taken along line BB in FIG. 1 ; and

[0025] Figure 6 is a flowchart of an operation example of the vehicle lighting system 1 . DETAILED DESCRIPTION

[0026] Hereinafter, a vehicle headlamp 10 as an embodiment of the present disclosure will be described with reference to the accompanying drawings. In the respective drawings, corresponding constituent elements are given the same reference numerals, and repeated descriptions will be omitted.

[0027] Figure 1 1 is a schematic configuration diagram of a vehicle lamp system 1 including a vehicle headlight 10 according to an embodiment.

[0028] like Figure 1 As shown, the vehicle lamp system 1 includes a vehicle headlight 10 (10L, 10R), a detection camera device 50, and a control device 60. The vehicle lamp system 1 is mounted on a vehicle V such as an automobile.

[0029] Figure 2 1 is a front view of a vehicle V equipped with the vehicle lighting system 1 .

[0030] like Figure 2 As shown, vehicle headlights 10 ( 10L, 10R) are provided on both left and right sides of a front end portion of a vehicle V. As shown in FIG.

[0031] Figure 3A and Figure 3B It is along Figure 2 Cross-sectional view taken along line AA in FIG.

[0032] like Figure 1 and Figure 3A As shown, each vehicle headlight 10 includes a lamp unit 20, a light detection device 30, and a defogger 40 (an example of an infrared light control unit in the present disclosure). The light detection device 30 and the detection camera device 50 form a LiDAR device. The lamp unit 20, the light detection device 30, and the defogger 40 are arranged in a lamp chamber S1, which is formed between a housing 70 and an outer lens 71 attached to the housing 70.

[0033] First, description will be given of a configuration example of the lamp unit 20. Hereinafter, description will be given of an example in which the lamp unit 20 is a projector type lamp unit.

[0034] like Figure 3A and Figure 3B As shown, the lamp unit 20 includes a semiconductor light emitting element 21 , a reflection surface 22 (reflector), a projection lens 23 , a reflection surface 24 (used as both a mask and a reflector), a bracket 25 , an optical axis adjustment mechanism 26 , and an extension portion 27 .

[0035] The semiconductor light emitting element 21 is, for example, a white LED light source. The white LED light source has a light emitting surface (for example, 1 square millimeter). The semiconductor light emitting element 21 is disposed at a first focus F1 of the reflective surface 22. 22 and the light emitting surface of the semiconductor light emitting element 21 is oriented upward.

[0036] The reflecting surface 22 is a spherical reflecting surface and has a first focus F1. 22 and the second focus F2 22 , first focus F1 22 Located at the rear of the vehicle, the second focus F2 22 The reflective surface 22 is provided in a state of covering the semiconductor light emitting element 21 (light emitting surface), so that light emitted from the semiconductor light emitting element 21 is incident on the reflective surface 22 .

[0037] The projection lens 23 is disposed in front of the reflection surface 22, and the focal point F of the projection lens 23 is 23 (Back focus) The second focus F2 located on the reflecting surface 22 22 The projection lens 23 inverts the light source image formed by the reflected light from the reflection surface 22 and projects it toward the front of the vehicle. 23 on the focal plane.

[0038] The reflecting surface 24 (which serves as both a mask and a reflector) is a plane-shaped reflecting surface having a focal point F disposed at the projection lens 23. 23 The front edge of the reflecting surface 24 is near the front edge and extends horizontally from the front edge toward the rear side of the vehicle (toward the semiconductor light emitting element 21). The front edge of the reflecting surface 24 includes a cutoff shape (Z-shaped step portion) (not shown) corresponding to the cutoff line (cutoffline) as the upper edge of the low beam distribution pattern.

[0039] The semiconductor light emitting element 21 , the reflecting surface 22 , the projection lens 23 , and the reflecting surface 24 (functioning as both a mask and a reflecting mirror) having the above-described configuration are attached to a bracket 25 .

[0040] The bracket 25 is attached to the housing 70 in a state in which it can be tilted in the vertical direction and the lateral direction. In contrast, the optical axis adjustment mechanism 26 is, for example, an aiming screw, and is attached to the housing 70 in a state in which it can rotate at the same position. The distal end portion of the aiming screw is screwed into the bracket 25. Therefore, by rotating the aiming screw to adjust the screwing amount of the aiming screw relative to the bracket 25, the bracket 25 is tilted in the vertical direction and the lateral direction corresponding to the screwing amount. Therefore, the optical axis of the lamp unit 20 can be adjusted (for example, leveling can be performed).

[0041] In the vehicle headlamp 10 having the above configuration, the low beam distribution pattern P can be formed by turning on the semiconductor light emitting element 21. Lo . Figure 4 The low beam distribution pattern P formed on a virtual vertical screen facing the front surface of the vehicle (set at a position about 25 m in front of the front surface of the vehicle) is shown. Lo An example of .

[0042] In the lamp unit 20 having the above configuration, when the semiconductor light emitting element 21 is turned on, the light emitted from the semiconductor light emitting element 21 is reflected on the reflection surface 22 and directed toward the focal point F of the projection lens 23. 23 Directed and close to the optical axis AX of the projection lens 23 23 Thereafter, the light is emitted from the projection lens 23 together with the reflected light further reflected (folded back and reflected) by the reflection surface 24 (which functions as both a mask and a reflector), and then transmitted through the visible light transmission area A1 of the outer lens 71 (see Figure 3A ), thereby irradiating forward.

[0043] Since such light (visible light) is transmitted through the outer lens 71 (visible light transmission area A1) and irradiated forward, a pattern such as Figure 4 The low beam distribution pattern P shown Lo The low beam distribution pattern P LoIt is excellent in long-distance visibility that allows relatively high brightness in the area near the cut-off line CL and in the area near the intersection between the H line and the V line.

[0044] The visible light transmission area A1 refers to an area in the outer lens 71 through which light emitted from the lamp unit 20 is transmitted. The light emitted from the lamp unit 20 may be used to form the entire low beam distribution pattern P. Lo light (see Figure 4 The area indicated by the reference numeral a1 in the figure) or may be a region for forming a low beam distribution pattern P Lo Part of the light (see Figure 4 A high luminous intensity region having relatively high luminous intensity and indicated by reference numeral a2).

[0045] Next, a configuration example of the light detection device 30 will be described.

[0046] Figure 5A is a schematic configuration diagram of the light detection device 30, and Figure 5B It is along Figure 5A Cross-sectional view taken through BB in FIG.

[0047] like Figure 5A and Figure 5B As shown, the light detection device 30 includes a light source system module 31 and a light receiving system module 32. The light source system module 31 and the light receiving system module 32 are accommodated in a housing 33 having a light shielding property.

[0048] The light source system module 31 emits infrared light having a wavelength in the infrared region of the solar blind band to a measurement target area located in front of the vehicle V. For example, the infrared region of the solar blind band is 895nm to 915nm and 1350nm to 1550nm. The wavelength in the infrared region of the solar blind band is a wavelength selected from the infrared region of the solar blind band, and is, for example, 905nm, 940nm and 1450nm. In contrast, the light receiving system module 32 receives reflected light (visible light) and outputs an electrical signal corresponding to the received reflected light, which is emitted from the lamp unit 20 (projection lens 23) and then returned due to reflection (scattering) on ​​the mist attached to the inner side of the outer lens 71. The light source system module 31 and the light receiving system module 32 are used as fog detection sensors for detecting the mist attached to the inner side of the outer lens 71.

[0049] The light source system module 31 includes a light source element 31 a , an oscillation circuit 31 b , and a light emission window 31 c .

[0050] The light source element 31a includes a semiconductor laser (semiconductor light emitting element) that emits (oscillates) infrared light having a wavelength in an infrared region of a solar-blind band, and a diffraction optical element (DOE), which converts the infrared light emitted from the semiconductor laser into a predetermined point-shaped beam pattern. The semiconductor laser is a vertical cavity surface emitting laser (VCSEL) including an emitter that emits, for example, a plurality of laser beams (24×64). The diffraction optical element is formed, for example, by a multi-bend unit array, and performs multi-branching of the infrared light (laser beam) emitted from the emitter of the VCSEL. The semiconductor laser is not limited to the VCSEL, and may be a strip laser diode (LD) or a photonic crystal surface emitting laser (PCSEL). The point-shaped beam pattern may be formed by a rotating mirror (MEMS mirror, electric mirror, or polygon mirror) instead of the diffraction optical element.

[0051] The oscillation circuit 31 b turns on or off the light source element 31 a in a predetermined pattern (pulse oscillation) in response to a control signal from a control device 60 (ECU: Electronic Control Unit).

[0052] The light emission window 31 c is formed of a filter (for example, a low-pass filter) that allows infrared light emitted from the light source element 31 a (diffraction grating) to be transmitted and blocks external light.

[0053] The light receiving system module 32 includes a light receiving element 32 a , a detection circuit 32 b , and a light receiving window 32 c .

[0054] The light receiving element 32a (four deflected light receiving elements) receives reflected light (visible light) and then outputs an electrical signal corresponding to the received reflected light, which is light emitted from the lamp unit 20 (projection lens 23) and then returned due to reflection (scattering) from the inner side of the outer lens 71 (visible light transmission area A1) or from the mist attached to the inner side.

[0055] The detection circuit 32 b is a circuit that converts the electric signal output from the light receiving element 32 a into an electric signal that can be recognized by the control device 60 (mist detection unit 65 ) provided downstream of the detection circuit 32 b and sends the converted electric signal to the control device 60 .

[0056] The light receiving window 32c is formed by a filter (bandpass filter) that allows reflected light (infrared light) to be transmitted and blocks external light that is not necessary for detection. The reflected light is light that is emitted from the lamp unit 20 (projection lens 23) and then returned due to reflection (scattering) from the inner side of the outer lens 71 (visible light transmission area A1) or from fog attached to the inner side.

[0057] In the light detection device 30 having the above configuration, the infrared light emitted from the light detection device 30 (light source element 31a) is converted by the diffraction optical element into a laser beam group that forms a dot pattern in the measurement target area, and then transmits through the infrared light transmission area A2 (see FIG. 1 ) of the outer lens 71. Figure 3A ), thereby irradiating forward. Figure 3A The angle θ1 in FIG. 1 indicates the infrared light transmission area A2 (see FIG. 1 ) emitted from the light detection device 30 (light source element 31 a ) and transmitted through the outer lens 71. Figure 3A ) range of infrared light.

[0058] Next, a configuration example of the defogger device 40 will be described.

[0059] In the vehicle headlight 10 having the above configuration, when the outer lens 71 is cooled by rain or the like, condensation occurs, causing fogging of the inner side of the outer lens 71. When the inner side of the outer lens 71 is fogged, the amount of light (visible light) emitted from the lamp unit 20 that is transmitted through the outer lens 71 (visible light transmission area A1) is reduced, and therefore, it is desirable to remove the fog attached to the inner side of the outer lens 71. The defogger 40 is used to remove such fog attached to the inner side of the outer lens 71.

[0060] like Figure 5A and Figure 5B As shown, the defogger 40 includes a light deflection element 41 and a light deflection element driving mechanism 42. The light deflection element 41 and the light deflection element driving mechanism 42 are accommodated in a housing 33 together with the light detection device 30, and the housing 33 has a light shielding property.

[0061] The light deflection element 41 is configured to deflect infrared light (a laser beam group forming a dot pattern in a measurement target area) emitted from the light detection device 30 and incident on the light deflection element 41 so that the deflected infrared light is irradiated toward the visible light transmission area A1 of the outer lens 71. More specifically, the light deflection element 41 is a diffuser.

[0062] The light deflection element driving mechanism 42 is to set the light deflection element 41 at the infrared light incident position P1 (see Figure 5C ) or infrared light non-incident position P2 (see Figure 5B ) actuator, the infrared light incident position P1 is located on the optical path of the infrared light emitted from the light detection device 30, and the infrared light non-incident position P2 is located outside the optical path of the infrared light emitted from the light detection device 30.

[0063] In the defogging device 40 having the above configuration, when the light deflection element 41 is disposed at the infrared light incident position P1 (see Figure 5C), the infrared light (laser beam group forming a dot pattern in the measurement target area) emitted from the light detection device 30 is deflected by the light deflection element 41, thereby irradiating the visible light transmission area A1 of the outer lens 71. In such a case, the infrared light is easily absorbed by water, and therefore, the infrared light (laser beam group forming a dot pattern in the measurement target area) emitted from the light detection device 30 and deflected by the light deflection element 41 is absorbed by the mist (water droplets) attached to the inner side of the outer lens 71 (visible light transmission area A1), thereby heating the mist (water droplets). Therefore, the mist (water droplets) attached to the inner side of the outer lens 71 (visible light transmission area A1) evaporates. As a result, the mist (water droplets) attached to the inner side of the outer lens 71 (visible light transmission area A1) can be removed. The wavelength range of the infrared light emitted from the light detection device 30 is preferably 895nm to 915nm or 1350nm to 1550nm. Alternatively, the range may be 915 nm to 960 nm, in which the infrared semiconductor light emitting element (infrared laser) has high light output, which is the limit of the absorption band.

[0064] On the contrary, when the light deflection element 41 is set at the infrared light non-incident position P2 (see Figure 5B ), the infrared light (laser beam group forming a dot pattern in the measurement target area) emitted from the light detection device 30 is transmitted through the outer lens 71 (infrared light transmission area A2) without being deflected by the light deflection element 41, thereby irradiating toward the measurement target area. Therefore, sensing of an object existing in the measurement target area can be performed.

[0065] The light detection device 30 and the defogger device 40 (housing 33) having the above-described configuration are attached to the bracket 25. By attaching the light detection device 30 and the defogger device 40 (housing 33) to the bracket 25 which is tiltable in the vertical direction and the lateral direction by the optical axis adjustment mechanism 26 in this manner, the optical axis of the infrared light (the laser beam group that forms a dot pattern in the measurement target area) emitted from the light detection device 30, and the adjustment of the optical axis of the lamp unit 20 performed by the optical axis adjustment mechanism 26 can be adjusted.

[0066] Next, the detection camera device 50 will be described.

[0067] The detection camera device 50 includes an image capturing element (not shown in the figure). The detection camera device 50 performs image capture (receives the return light) of the return light emitted from the light detection device 30 and then reflected on an object existing in the measurement target area through the image capturing element to form a range image whose pixel values ​​are taken as distance values. Figure 2As shown, the detection camera device 50 is disposed at the center in the vehicle width direction within the cabin of the vehicle V. The detection camera device 50 performs image capture of the front area of ​​the vehicle V through the windshield (wiper sweep area).

[0068] The image capturing element is, for example, a single photon counting type image capturing element (SPAD: Single Photon Avalanche Diode), which can measure the flight time (direct ToF) of infrared light emitted from the light detection device 30. Alternatively, a charge distribution type image capturing element can also be used, which obtains the distance to the detection object by detecting the phase shift of the light detection device 30 (indirect ToF).

[0069] Next, the control device 60 (control ECU) will be described.

[0070] like Figure 1 As shown, the control device 60 (control ECU: electronic control unit) includes, for example, a processor (not shown in the figure), a storage unit 61 and a memory 62.

[0071] The processor is, for example, a central processing unit (CPU). One processor may be used, or a plurality of processors may be used. The processor functions as an image capturing unit 63, an auxiliary range image forming unit 64, a mist detecting unit 65, and a defogging device control unit 66 by executing a predetermined program (not shown in the figure) read from a storage unit 61 (e.g., ROM) into a memory 62 (e.g., RAM). Some or all of these functions may be implemented by hardware.

[0072] The image capture unit 63 performs image capture of a right range image and a left range image as a main range image by controlling the light detection device 30 and the detection camera device 50. For example, the image capture unit 63 turns on the light detection device 30 at a predetermined light emission timing, and causes the detection camera device 50 to perform image capture at a predetermined timing. The right range image is a range image captured by the light detection device 30 disposed on the right side of the front end portion of the vehicle V (the right side in the direction toward the front side of the vehicle). In contrast, the left range image is a range image captured by the light detection device 30 disposed on the left side of the front end portion of the vehicle V (the left side in the direction toward the front side of the vehicle).

[0073] The auxiliary range image forming unit 64 forms an auxiliary range image based on the right range image and the left range image as the main range image sent from the detection camera device 50. The auxiliary range image formed by the auxiliary range image forming unit 64 is, for example, a composite range image obtained by composite the right range image and the left range image.

[0074] The mist detection unit 65 performs a mist detection process. The mist detection process is a process of detecting mist attached to the inner side of the outer lens 71 based on the output from the light receiving system module 32 (light receiving element 32a). For example, the mist detection process is a process of comparing the output from the light receiving system module 32 (light receiving element 32a) with a threshold value (for example, stored in the storage unit 61) to determine whether the output from the light receiving system module 32 (light receiving element 32a) is greater than the threshold value. When the output from the light receiving system module 32 (light receiving element 32a) is greater than the threshold value, the mist detection unit 65 detects the mist attached to the inner side of the outer lens 71. In contrast, when the output from the light receiving system module 32 (light receiving element 32a) is not greater than the threshold value, the mist detection unit 65 does not detect the mist attached to the inner side of the outer lens 71.

[0075] The defog device control unit 66 controls the light deflection element driving mechanism 42 (actuator) so that the light deflection element 41 is set at the infrared light incident position P1 (see Figure 5C ) or infrared light non-incident position P2 (see Figure 5B ), the infrared light incident position P1 is located on the optical path of the infrared light emitted from the light detection device 30, and the infrared light non-incident position P2 is located outside the optical path of the infrared light emitted from the light detection device 30. For example, when fog attached to the inner side of the outer lens 71 is detected, the defogger control unit 66 controls the light deflection element driving mechanism 42 (actuator) so that the light deflection element 41 is set at the infrared light incident position P1 located on the optical path of the infrared light emitted from the light detection device 30 (see Figure 5C In contrast, when fog adhering to the inner side of the outer lens 71 is not detected, the defogger control unit 66 controls the light deflection element driving mechanism 42 (actuator) so that the light deflection element 41 is set at the infrared light non-incident position P2 (see FIG. 1 ) which is located outside the optical path of the infrared light emitted from the light detection device 30. Figure 5B ).

[0076] Next, an operation example of the vehicle lamp system 1 having the above-described configuration will be described.

[0077] Figure 6 is a flowchart of an operation example of the vehicle lighting system 1 .

[0078] First, it is determined whether the vehicle headlight 10 is instructed to be turned on or off (for example, by a user) (step S10). For example, this can be achieved by the control device 60 executing a predetermined program.

[0079] Next, when the determination result in step S10 is "ON" (step S10: ON), the vehicle headlight 10 (semiconductor light emitting element 21) is turned on (step S11). This can be achieved by the control device 60 executing a predetermined program, for example.

[0080] Next, a mist detection process is performed (step S12). This can be achieved by the mist detection unit 65. The mist detection unit 65 compares the output from each light receiving system module 32 (light receiving element 32a) with a threshold value (for example, stored in the storage unit 61), and when the output from the light receiving system module 32 (light receiving element 32a) is greater than the threshold value, the mist detection unit 65 detects the mist attached to the inner side of the outer lens 71. In contrast, when the output from the light receiving system module 32 (light receiving element 32a) is not greater than the threshold value, the mist detection unit 65 does not detect the mist attached to the inner side of the outer lens 71.

[0081] Next, when mist is not detected as a result of step S12 (step S13: No), the light deflection element 41 is set at the infrared light non-incident position P2 (see Figure 5B )(Step S14). This can be achieved by the defogger control unit 66. The defogger control unit 66 controls the light deflection element driving mechanism 42 (actuator) so that the light deflection element 41 is set at the infrared light non-incident position P2 (see FIG. 1 ) which is located outside the optical path of the infrared light emitted from the light detection device 30. Figure 5B ).

[0082] Next, the light detection device 30 emits infrared light (step S15). At this operating point, the light deflection element 41 is set at the infrared light non-incident position P2 (see Figure 5B )(see step S14), and therefore, the infrared light emitted from the light detection device 30 (a laser beam group forming a dot pattern in the measurement target area) is transmitted through the outer lens 71 (infrared light transmission area A2) without being deflected by the light deflection element 41, thereby irradiating toward the measurement target area. Figure 3A and Figure 5B The angle θ1 in FIG. 1 indicates the infrared light transmission area A2 (see FIG. 1 ) emitted from the light detection device 30 (light source element 31 a ) and transmitted through the outer lens 71. Figure 3A ) of the infrared light. Therefore, sensing of an object existing in the measurement target area can be performed. In step S15, a first driving voltage corresponding to, for example, a period of 1 μs and a pulse width of 10 ns is applied to the light source element 31 a (semiconductor laser) of the light detection device 30 by PWM control.

[0083] In contrast, when mist is detected as a result of step S12 (step S13: Yes), the light deflection element 41 is set at the infrared light incident position P1 (see Figure 5C )(Step S16). This can be achieved by the defogger control unit 66. The defogger control unit 66 controls the light deflection element driving mechanism 42 (actuator) so that the light deflection element 41 is set at the infrared light incident position P1 (see FIG. 1 ) located on the optical path of the infrared light emitted from the light detection device 30. Figure 5C ).

[0084] Next, the light detection device 30 emits infrared light (step S17). At this operating point, the light deflection element 41 is set at the infrared light incident position P1 (see Figure 5C ) (see step S16 ), and therefore, the infrared light (laser beam group forming a dot pattern in the measurement target area) emitted from the light detection device 30 is deflected by the light deflection element 41 so as to be irradiated toward the visible light transmission area A1 of the outer lens 71 . Figure 3B and Figure 5C The angle θ2 in FIG. 1 indicates the visible light transmission area A1 (see FIG. 1 ) emitted from the light detection device 30 (light source element 31 a ) and directed toward the outer lens 71. Figure 3B ) is irradiated with infrared light. In such a case, infrared light is easily absorbed by water, and therefore, the infrared light (laser beam group forming a dot pattern in the measurement target area) emitted from the light detection device 30 and deflected by the light deflection element 41 is absorbed by the mist (water droplets) attached to the inner side of the outer lens 71 (visible light transmission area A1), thereby heating the mist (water droplets). Therefore, the mist (water droplets) attached to the inner side of the outer lens 71 (visible light transmission area A1) evaporates. As a result, the mist (water droplets) attached to the inner side of the outer lens 71 (visible light transmission area A1) can be removed.

[0085] In step S17, a second driving voltage (effective voltage) higher than the above-mentioned first driving voltage (effective voltage) is applied to the light source element 31a (semiconductor laser) of the light detection device 30 by PWM control, and the second driving voltage corresponds to a duty ratio of, for example, 1 / 10 to 1 / 100. Thus, compared with the case where the above-mentioned first driving voltage (effective voltage) is applied, the intensity of the infrared light irradiated to the visible light transmission area A1 of the outer lens 71 is increased. Therefore, the evaporation of the mist (water droplets) attached to the inner side of the outer lens 71 (visible light transmission area A1) is promoted. As a result, the mist (water droplets) attached to the inner side of the outer lens 71 (visible light transmission area A1) can be quickly removed.

[0086] Thereafter, the processes in the above corresponding steps are repeatedly performed until mist is no longer detected in step S13.

[0087] In contrast, when the determination result in step S10 is "off" (step S10: off), the vehicle headlight 10 (semiconductor light emitting element 21) is turned off (step S18). This can be achieved, for example, by the control device 60 executing a predetermined program.

[0088] Next, the light deflection element 41 is set at the infrared light non-incident position P2 (see Figure 5B )(Step S19). This can be achieved by the defogger control unit 66. The defogger control unit 66 controls the light deflection element driving mechanism 42 (actuator) so that the light deflection element 41 is set at the infrared light non-incident position P2 (see FIG. 1 ) which is located outside the optical path of the infrared light emitted from the light detection device 30. Figure 5B ).

[0089] Next, the light detection device 30 emits infrared light (step S20). At this operating point, the light deflection element 41 is set at the infrared light non-incident position P2 (see Figure 5B )(see step S19), and therefore, the infrared light emitted from the light detection device 30 (a laser beam group forming a dot pattern in the measurement target area) is transmitted through the outer lens 71 (infrared light transmission area A2) without being deflected by the light deflection element 41, thereby irradiating toward the measurement target area. Figure 3A and Figure 5B The angle θ1 in FIG. 1 indicates the infrared light transmission area A2 (see FIG. 1 ) emitted from the light detection device 30 (light source element 31 a ) and transmitted through the outer lens 71. Figure 3A ) range of infrared light. Therefore, sensing of an object present in the measurement target area can be performed. In step S20, a first driving voltage corresponding to a period of, for example, 1 μs and a pulse width of 10 ns is applied to the light source element 31 a (semiconductor laser) of the light detection device 30 by PWM control.

[0090] As has been described above, according to the present embodiment, the mist attached to the outer lens 71 can be removed without using a heater.

[0091] This can be achieved because an infrared light control unit (e.g., a light deflection element and a light deflection element driving mechanism) is provided to control the infrared light emitted from the light detection device so that the infrared light emitted from the light detection device 30 is irradiated toward the visible light transmission area of ​​the outer lens.

[0092] Next, modification examples will be described.

[0093] In the above-mentioned embodiment, description has been made with respect to an example of using a projector-type lamp unit as the lamp unit 20. However, the configuration is not limited to this configuration. That is, as long as the lamp unit emits light (visible light) transmitted through the outer lens 71 (visible light transmission area A1) to form a light distribution pattern for a headlight (e.g., a low beam distribution pattern, a high beam distribution pattern, or a light distribution pattern for an adaptive high beam system (ADB)), a lamp unit having any configuration may be used. For example, for the lamp unit 20, a lamp unit different from the projector-type lamp unit may be used, such as a reflector-type lamp unit, a direct projection-type (so-called direct-type) lamp unit, a lamp unit using a light conductor (e.g., a light guide rod or a light guide plate), or a lamp unit other than the above.

[0094] In the above-mentioned embodiment, it has been described that the defogger 40 has the light deflection element 41 disposed at the infrared light incident position P1 (see Figure 5C ) or infrared light non-incident position P2 (see Figure 5B ), the infrared light incident position P1 is located on the optical path of the infrared light emitted from the light detection device 30, and the infrared light non-incident position P2 is located outside the optical path of the infrared light emitted from the light detection device 30. However, the configuration is not limited to this configuration. For example, the defogger device 40 may cause the light deflection element 41 to be disposed at such an infrared light incident position or an infrared light non-incident position, that is, the infrared light incident position is located on the optical path of the infrared light emitted from an infrared light emitting device other than the light detection device 30 (for example, various infrared light emitting devices used in LiDAR devices, such as LiDAR sensors), and the infrared light non-incident position is located outside the optical path of the infrared light emitted from the infrared light emitting device.

[0095] All the respective numerical values ​​shown in the above-described respective embodiments are examples, and it is needless to say that appropriate numerical values ​​different from the respective numerical values ​​shown in the above-described respective embodiments may be used.

[0096] The above-mentioned corresponding embodiments are merely examples in all aspects. The present disclosure should not be interpreted as being limited by the description of the above-mentioned corresponding embodiments. The present disclosure may be specifically implemented in various other forms without departing from the spirit and basic features of the present disclosure.

Claims

1. A vehicle headlight, comprising: case; an outer lens attached to the housing to form a light chamber between the outer lens and the housing; a lamp unit configured to emit visible light transmitted through a visible light transmission region of the outer lens, the lamp unit being disposed in the lamp chamber; a light detection device configured to emit infrared light transmitted through the infrared light transmission area of ​​the outer lens, the light detection device being disposed in the lamp chamber; as well as An infrared light control unit is configured to control the infrared light emitted from the light detection device so that the infrared light emitted from the light detection device is irradiated toward the visible light transmission area of ​​the outer lens.

2. The vehicle headlamp according to claim 1, wherein: The infrared light control unit includes a light deflection element and a light deflection element driving mechanism. The light deflection element is configured to deflect the infrared light so that the deflected infrared light is irradiated toward the visible light transmission area of ​​the outer lens, the infrared light is emitted from the light detection device and is incident on the light deflection element, and The light deflection element driving mechanism sets the light deflection element at an infrared light incident position or an infrared light non-incident position, wherein the infrared light incident position is located on the optical path of the infrared light emitted from the light detection device, and the infrared light non-incident position is located outside the optical path of the infrared light emitted from the light detection device.

3. The vehicle headlamp according to claim 2, wherein: When the light deflection element is disposed at the infrared light non-incident position, the light detection device emits the infrared light by applying a first driving voltage, and When the light deflection element is disposed at the infrared light incident position, the light detection device emits the infrared light by applying a second driving voltage higher than the first driving voltage.

4. The vehicle headlight according to claim 2, further comprising: a fog detection unit, wherein the fog detection unit is configured to perform a fog detection process for detecting fog attached to the outer lens, When the mist is detected, the light deflection element driving mechanism sets the light deflection element at the infrared light incident position, and when the mist is not detected, the light deflection element driving mechanism sets the light deflection element at the infrared light non-incident position.

5. The vehicle headlamp according to claim 1, wherein: The wavelength of the infrared light is selected from the range of 895 nm to 960 nm and the range of 1350 nm to 1550 nm.

6. The vehicle headlamp according to claim 1, wherein: The light detection device includes a semiconductor light emitting element configured to emit the infrared light, and The semiconductor light emitting element is any one of a stripe LD, a VCSEL, and a PCSEL.

7. The vehicle headlight according to claim 1, further comprising: a bracket to which the lamp unit is attached; as well as an optical axis adjustment mechanism configured to adjust the optical axis of the lamp unit by tilting the bracket, Wherein, the light detection device is attached to the bracket.

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