Vehicle headlights

Abstract

To provide a front headlight for a vehicle that is able to prevent deterioration of visibility ahead of an own vehicle caused by an evaporation phenomenon.SOLUTION: A front headlamp for a vehicle includes: a first lamp unit capable of changing a light distribution pattern of a low beam; a second lamp unit capable of changing a light distribution pattern of light forming a high beam; a detection unit configured to detect an oncoming vehicle 95; and a control unit. When the oncoming vehicle 95 is detected, the control unit controls the first lamp unit such that a total amount of luminous flux of light from the first lamp unit emitted to a predetermined area 175 overlapping the oncoming vehicle 95 in a vertical direction of the light distribution pattern of the low beam and including a part of a cutoff line of the low beam becomes smaller than that when the oncoming vehicle 95 is not detected; and controls the second lamp unit such that a total amount of luminous flux of light from the second lamp unit emitted to a specific area overlapping the oncoming vehicle 95 and connected to the predetermined area 175, in the light distribution pattern of light exiting from the second lamp unit is smaller than that when the oncoming vehicle 95 is not detected.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to a vehicle headlamp. [Background technology]

[0002] Among vehicle headlamps, such as automobile headlights, there are known those that can change the light distribution pattern of the emitted light. Patent Document 1 below discloses a vehicle headlamp that can change the light distribution pattern of the emitted light between a low-beam light distribution pattern and a light distribution pattern for urban areas. This light distribution pattern for urban areas is a light distribution pattern in which the low-beam light distribution pattern is elongated in the left-right direction.

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-146621 Summary of the Invention

[0004] However, when there is an object that the driver should pay attention to, such as a person, at a position where the light from the headlights of the own vehicle and the light from the headlights of an oncoming vehicle intersect, the driver may have difficulty in seeing the object. This phenomenon is sometimes called evaporation, and can occur even when the light emitted from the headlights of the own vehicle is a low beam or a light with a light distribution pattern for urban areas as described in Patent Document 1. For this reason, there is a demand for preventing the evaporation phenomenon from making it difficult for the driver to see objects that the driver should pay attention to, such as a person.

[0005] SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a vehicle headlamp that can suppress a decrease in visibility ahead of the vehicle caused by evaporation.

[0006] In order to achieve the above-mentioned object, the vehicle headlamp of the present invention comprises a lighting unit capable of changing the low beam light distribution pattern, a detection unit that detects an evaporation area that meets the requirements for an evaporation phenomenon to occur in the area irradiated by the low beam, and a control unit, wherein when the evaporation area is detected by the detection unit, the control unit controls the lighting unit so that the total luminous flux of light from the lighting unit irradiated to a specified area of ​​the low beam light distribution pattern that overlaps at least a portion of the evaporation area is smaller than when the evaporation area is not detected.

[0007] The evaporation area is an area in the low beam illumination region that overlaps with at least one of an object that is difficult to see due to evaporation and the shadow of the object. With this vehicle headlamp, at least a portion of the evaporation area is darkened, making it easier for the driver of the vehicle to see at least a portion of the evaporation area, compared to when the total luminous flux of light from the lamp unit irradiating the predetermined region is not reduced. Therefore, with this vehicle headlamp, it is possible to make it easier to see objects, such as people, that are difficult to see due to evaporation, and to suppress a decrease in visibility ahead of the vehicle caused by evaporation, compared to the above case.

[0008] The predetermined area may overlap the entire evaporation area.

[0009] By adopting such a configuration, the entire evaporation area can be easily viewed.

[0010] The predetermined area may cross at least a part of the evaporation area in the left-right direction.

[0011] For example, when a pedestrian crossing a road becomes difficult to see due to evaporation, the relative position of the evaporation area corresponding to the pedestrian with respect to the host vehicle tends to change in the left-right direction. With this vehicle headlamp, even if the relative position of the evaporation area with respect to the host vehicle changes in the left-right direction, the predetermined area and the evaporation area can be made to overlap, thereby making it possible to prevent objects moving in the left-right direction, such as pedestrians crossing a road, from becoming difficult to see.

[0012] The predetermined area may include a part of the cutoff line of the low beam.

[0013] The predetermined area may be spaced apart from a lower edge of the low beam light distribution pattern.

[0014] By adopting such a configuration, it is possible to suppress a decrease in visibility immediately in front of the vehicle, compared to when the predetermined area includes the lower edge of the low beam light distribution pattern.

[0015] The detection unit may detect, as the evaporated region, a region that is sandwiched in the left-right direction between bright regions having a predetermined luminance value or more and that includes a dark region whose width in the left-right direction is within a predetermined range.

[0016] For example, a portion of an object that is difficult to see due to evaporation caused by light from the headlights of an oncoming vehicle tends to be perceived by the driver of the vehicle as a dark region sandwiched between regions brightened by the light from the headlights of the oncoming vehicle. Furthermore, a shadow formed on the road surface, etc., by an object blocking the light from the headlights of the oncoming vehicle also tends to be sandwiched between regions brightened by the light from the headlights of the oncoming vehicle. Furthermore, the width of these dark regions in the horizontal direction tends to be smaller than the width of the oncoming vehicle in the horizontal direction, for example. Therefore, in this vehicle headlight, the predetermined brightness value and the predetermined range can be set so that the bright region corresponds to the region brightened by the light from the headlights of the oncoming vehicle, and the dark region corresponds to a portion of the object that is difficult to see due to evaporation or a portion of the shadow of the object. In other words, the dark region can be configured to be an evaporation region. Therefore, in this vehicle headlight, for example, the detection unit can detect the evaporation region by image processing image data captured in front of the vehicle.

[0017] In addition, the vehicle headlamp of the present invention comprises a lighting unit capable of changing the low beam light distribution pattern, a detection unit that detects oncoming vehicles, and a control unit, and when the oncoming vehicle is detected by the detection unit, the control unit controls the lighting unit so that the total luminous flux of light from the lighting unit irradiated to a predetermined area of ​​the low beam light distribution pattern that overlaps with the oncoming vehicle in the vertical direction and includes part of the low beam cut-off line is reduced compared to when the oncoming vehicle is not detected.

[0018] From the driver's perspective, the area of ​​the low-beam light distribution pattern that overlaps with an oncoming vehicle in the vertical direction generally overlaps with the area in front of the oncoming vehicle. Furthermore, objects such as people that are difficult for the driver to see due to evaporation caused by the light from the oncoming vehicle's headlights and the low beam of the vehicle tend to be located across the low-beam cutoff line from the driver's perspective. With this vehicle headlamp, the total luminous flux of light from the lamp unit irradiating a predetermined area of ​​the low-beam light distribution pattern that overlaps with the oncoming vehicle in the vertical direction and includes a portion of the low-beam cutoff line is reduced. Therefore, even if an object such as a pedestrian is located in the area in front of the oncoming vehicle and the object becomes difficult for the driver to see due to evaporation caused by the light from the oncoming vehicle's headlights and the low beam of the vehicle, the reduction in visibility of the object can be suppressed compared to when the total luminous flux of light from the lamp unit irradiating the predetermined area is not reduced. Therefore, this vehicle headlamp can suppress the reduction in visibility ahead of the vehicle caused by evaporation.

[0019] The above-mentioned vehicle headlamp may further include another lighting unit capable of changing the light distribution pattern of light irradiated onto an area at least a portion of which is located above the low beam and connected to the cut-off line, and the control unit may control the other lighting unit so that, when the oncoming vehicle is detected by the detection unit, the total luminous flux of light from the other lighting unit irradiated onto a specific area that overlaps with the oncoming vehicle and is connected to the specified area is reduced in the light distribution pattern of light emitted from the other lighting unit compared to when the oncoming vehicle is not detected.

[0020] As described above, the specific area overlaps with an oncoming vehicle, thereby improving forward visibility of the vehicle using light from another lamp unit while minimizing dazzling of the driver of the oncoming vehicle by light from the other lamp unit. Furthermore, the specific area is connected to a predetermined area that includes a portion of the cutoff line. As described above, an object that becomes difficult to see due to evaporation tends to be located across the cutoff line. Therefore, a portion of the object can be made to overlap with the specific area, minimizing the difficulty in seeing that portion of the object due to evaporation caused by light from another lamp unit and the headlights of the oncoming vehicle.

[0021] As described above, the present invention provides a vehicle headlamp that can suppress a decrease in visibility ahead of the vehicle that is caused by evaporation. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a plan view conceptually showing a vehicle equipped with a vehicle headlamp according to a first embodiment of the present invention. [Figure 2] 2 is a cross-sectional view taken along the vertical direction, schematically showing the first lamp unit shown in FIG. 1. FIG. [Figure 3] 3 is a front view schematically showing the light source unit and the shade shown in FIG. 2. FIG. [Figure 4] 2 is a cross-sectional view taken along the vertical direction, schematically showing the second lamp unit shown in FIG. 1. FIG. [Figure 5]FIG. 5 is a front view schematically showing the light distribution pattern forming section shown in FIG. [Figure 6] FIG. 2 is a diagram showing a light distribution pattern of a low beam. [Figure 7] FIG. 3 is a diagram showing an example of a control flowchart of a control unit in the first embodiment. [Figure 8] 10 is a diagram schematically illustrating a portion of an example of image data obtained by performing binarization processing on image data obtained by a camera. FIG. [Figure 9] FIG. 2 is a diagram illustrating an example of a light distribution pattern in the first embodiment. [Figure 10] FIG. 10 is a diagram illustrating an example of a light distribution pattern in the second embodiment. [Figure 11] FIG. 10 is a diagram showing another example of a light distribution pattern in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments for carrying out a vehicle headlamp according to the present invention will be illustrated with reference to the accompanying drawings. The embodiments illustrated below are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention can be modified or improved from the following embodiments without departing from the spirit thereof. Furthermore, in the accompanying drawings, the dimensions of each component may be exaggerated to facilitate understanding.

[0024] (First embodiment) FIG. 1 is a plan view conceptually showing a vehicle equipped with a vehicle headlamp according to this embodiment. As shown in FIG. 1, the vehicle 100 according to this embodiment includes a vehicle headlamp 1, a camera 110, and a light switch 120. The vehicle headlamp 1 according to this embodiment is a headlamp for an automobile, and includes as its main components a pair of left and right lamp units 5, a control unit CO, a detection unit 30, and a pair of power supply circuits 40. In this specification, unless otherwise specified, "right" means the right side from the perspective of the driver of the vehicle 100, which is the host vehicle, and "left" means the left side from the perspective of the driver.

[0025] In this embodiment, the pair of lamp units 5 have shapes that are generally symmetrical to each other in the left-right direction of the vehicle 100, and emit light in a changeable light distribution pattern toward the front of the vehicle 100. Furthermore, the configuration of one lamp unit 5 is the same as the configuration of the other lamp unit 5, except that the shapes are generally symmetrical. Therefore, hereinafter, only one lamp unit 5 will be described, and a description of the other lamp unit 5 will be omitted.

[0026] The lamp section 5 of this embodiment includes a first lamp unit 10 and a second lamp unit 20. The second lamp unit 20 is disposed closer to the center of the vehicle 100 than the first lamp unit 10.

[0027] Fig. 2 is a cross-sectional view taken along the vertical direction, schematically illustrating the first lamp unit 10 shown in Fig. 1. As shown in Fig. 2, the first lamp unit 10 mainly includes a light source unit 12, a shade 13, a projection lens 15, and a housing 16.

[0028] The housing 16 mainly comprises a lamp housing 17, a front cover 18, and a back cover 19. The front of the lamp housing 17 is open, and the front cover 18 is fixed to the lamp housing 17 so as to close the opening. In addition, a smaller opening is formed in the rear of the lamp housing 17 than in the front, and a back cover 19 is fixed to the lamp housing 17 so as to close the opening. The space formed by the lamp housing 17, the front cover 18, and the back cover 19 is a lamp chamber 10R, and the light source unit 12, the shade 13, and the projection lens 15 are housed in this lamp chamber 10R.

[0029] FIG. 3 is a front view schematically illustrating the light source unit 12 and the shade 13 shown in FIG. 2. As shown in FIGS. 2 and 3, the light source unit 12 of this embodiment includes a plurality of light-emitting elements 12a and a circuit board 12b on which the plurality of light-emitting elements 12a are mounted. The plurality of light-emitting elements 12a are arranged in a matrix to form rows in the vertical and horizontal directions, and emit light forward. Each of the light-emitting elements 12a is capable of individually adjusting the amount of light emitted. The light-emitting elements 12a may be, for example, light-emitting diodes (LEDs). The number of light-emitting elements 12a, the number of rows of light-emitting elements 12a, the number of light-emitting elements 12a in each row, the arrangement direction of the light-emitting elements 12a, and the type of light-emitting elements 12a are not particularly limited.

[0030] Such a light source unit 12 can form a desired light distribution pattern by selecting the light-emitting elements 12a that emit light. Furthermore, the light source unit 12 can adjust the light intensity distribution in the desired light distribution pattern by adjusting the amount of light emitted from each light-emitting element 12a. Therefore, the light source unit 12 can form a light distribution pattern according to the amount of light emitted from the multiple light-emitting elements 12a.

[0031] The shade 13 has a light-shielding portion 13a and a fixing portion 13b. In this embodiment, the light-shielding portion 13a and the fixing portion 13b are integrally formed by bending a plate-shaped member. The light-shielding portion 13a extends in the left-right direction in front of the light source unit 12, and the fixing portion 13b is connected to its lower end. The fixing portion 13b extends rearward from the lower end of the light-shielding portion 13a, and its rear end is fixed to the circuit board 12b. The upper edge of the light-shielding portion 13a consists of a first edge 13e1, a second edge 13e2, and a third edge 13e3. The first edge 13e1 extends generally horizontally. The second edge 13e2 extends linearly from one end of the first edge 13e1 downward and opposite the first edge 13e1. The third edge 13e3 extends substantially horizontally from the end of the second edge 13e2 opposite to the first edge 13e1 toward the opposite side to the first edge 13e1. Such a light-shielding portion 13a blocks part of the light emitted from the light source unit 12.

[0032] The projection lens 15 is a lens that adjusts the divergence angle of incident light. In this embodiment, the projection lens 15 is a lens whose entrance and exit surfaces are formed in a convex shape and is disposed forward of the shade 13. The rear focal point of the projection lens 15 is located at or near the upper edge of the shading portion 13a. As described above, a portion of the light emitted from the light source unit 12 is blocked by the shading portion 13a, and another portion of the light emitted from the light source unit 12 enters the projection lens 15, and light with a predetermined light distribution pattern corresponding to the shape of the shading portion 13a is emitted from the projection lens 15. In this manner, the light having the predetermined light distribution pattern emitted from the projection lens 15 is emitted from the first lamp unit 10 toward the front of the vehicle 100 via the front cover 18. Note that this predetermined light distribution pattern is a light distribution pattern that is vertically and horizontally inverted from the light distribution pattern when a portion of the light is blocked by the shading portion 13a.

[0033] Fig. 4 is a cross-sectional view taken along the vertical direction, schematically illustrating the second lamp unit 20 shown in Fig. 1. As shown in Fig. 4, the second lamp unit 20 mainly comprises a light distribution pattern forming section 22, a projection lens 25, and a housing 26. The housing 26 has a similar configuration to the housing 16 of the first lamp unit 10, and mainly comprises a lamp housing 27, a front cover 28, and a back cover 29. The light distribution pattern forming section 22 and the projection lens 25 are housed within a lamp chamber 20R formed by the housing 26.

[0034] FIG. 5 is a front view schematically illustrating the light distribution pattern forming unit 22 shown in FIG. 4. As shown in FIGS. 4 and 5, the light distribution pattern forming unit 22 of this embodiment includes a plurality of light-emitting elements 23 as a light-emitting unit that emits light, and a circuit board 24 on which the plurality of light-emitting elements 23 are mounted. The plurality of light-emitting elements 23 are arranged in a matrix to form rows in the vertical and horizontal directions, and emit light forward. The light-emitting elements 23 are capable of individually changing the amount of light they emit. Similar to the light source unit 12, this light distribution pattern forming unit 22 can form a predetermined light distribution pattern according to the amount of light emitted from the plurality of light-emitting elements 23. In this embodiment, the light-emitting elements 23 are LEDs, and the light distribution pattern forming unit 22 is a so-called LED array. Note that the number of light-emitting elements 23, the number of rows of light-emitting elements 23, the number of light-emitting elements 23 in each row, the direction in which the light-emitting elements 23 are arranged, and the type of light-emitting elements 23 are not particularly limited.

[0035] Like the projection lens 15, the projection lens 25 is a lens that adjusts the divergence angle of incident light. The projection lens 25 is disposed forward of the light distribution pattern forming unit 22. Light emitted from the light distribution pattern forming unit 22 is incident on the projection lens 25, and the divergence angle of this light is adjusted by the projection lens 25. The projection lens 25 is a lens whose entrance and exit surfaces are convex, and the rear focal point of the projection lens 25 is located on or near the light exit surface of any one of the light-emitting elements 23 in the light distribution pattern forming unit 22. Light emitted from the light distribution pattern forming unit 22 is incident on the projection lens 15, and light with a predetermined light distribution pattern corresponding to the amount of light emitted from the plurality of light-emitting elements 23 is emitted from the projection lens 15. The light having the predetermined light distribution pattern emitted from the projection lens 25 is emitted from the second lamp unit 20 through the front cover 28 toward the front of the vehicle 100. This predetermined light distribution pattern is a light distribution pattern obtained by vertically and horizontally inverting the light distribution pattern before entering the projection lens 15.

[0036] 1 is composed of an integrated circuit such as a microcontroller, an integrated circuit (IC), a large-scale integrated circuit (LSI), or an application-specific integrated circuit (ASIC), or an NC (numerical control) device. When an NC device is used for the control unit CO, the control unit CO may or may not use a machine learning device. As will be described later, the control unit CO controls the first lamp unit 10 and the second lamp unit 20.

[0037] A light switch 120 is connected to the control unit CO. The light switch 120 in this embodiment is a switch that selects between emitting a low beam, emitting a high beam, and not emitting light. For example, the light switch 120 outputs a signal indicating the selected state to the control unit CO, but does not output a signal to the control unit CO when not emitting light is selected. Although details will be described later, in this embodiment, a low beam light distribution pattern is formed by the light emitted from the first lamp unit 10, and a high beam light distribution pattern is formed by the light emitted from the first lamp unit 10 and the second lamp unit 20.

[0038] The camera 110 of this embodiment is attached to the front of the vehicle 100, captures images of the area ahead of the vehicle 100 at predetermined time intervals, for example, at intervals of 1 / 30 seconds, and outputs the resulting image data to the detection unit 30. Examples of the camera 110 include a C-MOS (Complementary Metal Oxide Semiconductor) camera and a CCD (Charged Coupled Device) camera.

[0039] The detection unit 30 of this embodiment detects an evaporation area that satisfies the requirements for evaporation to occur in the area illuminated by the low beam, based on image data obtained by the camera 110. This evaporation area is an area that overlaps with at least one of an object that is difficult to see due to evaporation in the area illuminated by the low beam and the shadow of the object. An example of the object is something that the driver should be careful of, such as a person. The method for detecting an evaporation area by the detection unit 30 will be described later. When the detection unit 30 detects an evaporation area, the detection unit 30 outputs a signal indicating information related to the evaporation area, such as the presence of the evaporation area and the position of the evaporation area relative to the vehicle 100, to the control unit CO. In other words, the detection of an evaporation area by the detection unit 30 involves changing the output signal depending on the case, depending on the image data obtained by the camera 110.

[0040] The detection unit 30 of this embodiment detects an oncoming vehicle based on image data obtained by the camera 110 and calculates the distance from the vehicle 100 to the oncoming vehicle. The detection unit 30 then outputs a signal indicating information related to the oncoming vehicle, such as the presence of the oncoming vehicle, the position of the oncoming vehicle relative to the vehicle 100, and the distance from the vehicle 100 to the oncoming vehicle, to the control unit CO. In other words, the detection of an oncoming vehicle by the detection unit 30 involves changing the signal to be output depending on the case, depending on the image captured by the camera 110. The configuration of the detection unit 30 may be, for example, the same as that of the control unit CO.

[0041] The method for detecting an oncoming vehicle by the detection unit 30, the method for calculating the distance from the vehicle 100 to the oncoming vehicle, and the information related to the oncoming vehicle output from the detection unit 30 to the control unit CO are not particularly limited. For example, when an oncoming vehicle is present, a pair of white light spots due to light emitted from the headlights of the oncoming vehicle are reflected in the image acquired by the camera 110. Therefore, the detection unit 30 may detect the oncoming vehicle based on whether or not the pair of light spots are reflected. The detection unit 30 may also calculate the distance from the vehicle 100 to the oncoming vehicle based on the distance between a pair of intersections in the image. Furthermore, if the vehicle 100 is equipped with a sensor device capable of detecting an object located in front of the vehicle 100, the detection unit 30 may detect the oncoming vehicle and calculate the distance from the vehicle 100 to the oncoming vehicle based on at least one of the image acquired by the camera 110 and a signal input from the sensor device. Examples of the sensor device include millimeter-wave radar and LIDAR. Furthermore, the distance from the vehicle 100 to the oncoming vehicle may be calculated by a calculation unit separate from the detection unit 30.

[0042] One power supply circuit 40 corresponds to one of the lighting units 5, and the other power supply circuit 40 corresponds to the other lighting unit 5. Each power supply circuit 40 includes a driver, and when a signal is input from the control unit CO, the driver adjusts the power supplied to each light-emitting element 12 a of the first lighting unit 10 and each light-emitting element 23 of the second lighting unit 20. In this way, the amount of light emitted from each of these light-emitting elements 12 a, 23 is adjusted. The driver of the power supply circuit 40 may adjust the power supplied to each of the light-emitting elements 12 a, 23 by PWM (Pulse Width Modulation) control.

[0043] The memory ME is configured to store information and to be able to read the stored information. The memory ME is, for example, a non-transitory recording medium, and is preferably a semiconductor recording medium such as a random access memory (RAM) or a read only memory (ROM), but may include any type of recording medium, such as an optical recording medium or a magnetic recording medium. Note that "non-transitory" recording media includes all computer-readable recording media except for transient, propagating signals, and does not exclude volatile recording media.

[0044] In this embodiment, the memory ME stores a table in which information related to the light distribution pattern formed by the light emitted from the first lamp unit 10, for example, information related to the power supplied to each light-emitting element 12a, is associated with information related to the evaporation area detected by the detection unit 30. The memory ME also stores a table in which information related to the light distribution pattern formed by the light emitted from the second lamp unit 20, for example, information related to the power supplied to each light-emitting element 23, is associated with information related to an oncoming vehicle detected by the detection unit 30.

[0045] Next, the low beam emitted from the vehicle headlamp 1 will be described.

[0046] When a signal indicating emission of a low beam is input from the light switch 120, the control unit CO controls the first lamp unit 10 so that a low beam is emitted from the vehicle headlamp 1, and does not drive the second lamp unit 20. Specifically, the control unit CO refers to information stored in the memory ME and outputs a signal corresponding to the low beam to the power supply circuit 40. As a result, the driver of the power supply circuit 40 adjusts the power supplied to each light-emitting element 12a so that light that becomes a low beam is emitted from the first lamp unit 10.

[0047] FIG. 6 is a diagram showing a low beam light distribution pattern in this embodiment. In FIG. 6, S indicates a horizontal line, V indicates a vertical line passing through the center of the vehicle 100 in the lateral direction, and the low beam light distribution pattern PL formed on a virtual vertical screen located 25 m ahead of the vehicle 100 is indicated by a thick line. Also in FIG. 6, an area HA that can be irradiated with light from the second lamp unit 20 is indicated by a dashed line. The outline of the light distribution pattern is defined, for example, by isointensity lines formed by a collection of points where the light intensity is a predetermined percentage of the maximum light intensity value in the light distribution pattern. The outline of the light distribution pattern in this embodiment is defined by isointensity lines formed by a collection of points where the light intensity is 1.5% of the maximum light intensity value in the light distribution pattern.

[0048] The upper edge of the low-beam light distribution pattern PL of this embodiment is composed of cutoff lines CL1, CL2, and CL3. The cutoff line CL1 extends horizontally to the right from an elbow point EP, which is located below the horizontal line S and on or near the vertical line V. The cutoff line CL2 extends diagonally upward to the left from the elbow point EP, and the end of the cutoff line CL2 opposite to the elbow point EP is located above the horizontal line S. The cutoff line CL3 extends horizontally to the left from the end of the cutoff line CL2 opposite to the elbow point EP. The upper edge of the low-beam light distribution pattern PL corresponds to the shape of the upper end of the light-shielding portion 13a. In countries and regions where vehicles drive on the right side of the road, the low-beam light distribution pattern is generally symmetrical to the low-beam light distribution pattern PL shown in FIG. 6.

[0049] In addition, in the vehicle headlamp 1 of this embodiment, a high beam is formed by the low beam and light of a predetermined light distribution pattern emitted from the second lamp unit 20, and the outline of the light of this predetermined light distribution pattern is the same as the outline of the area HA.

[0050] In this embodiment, in response to detection of an evaporation area by the detection unit 30, the light distribution pattern of light emitted from the first lamp unit 10 changes to a light distribution pattern corresponding to the evaporation area, and in response to detection of an oncoming vehicle by the detection unit 30, the light distribution pattern of light emitted from the second lamp unit 20 changes to a light distribution pattern corresponding to the oncoming vehicle. Therefore, for example, when low beam emission is selected by the light switch 120, the light distribution pattern of light emitted by the vehicle headlamp 1 is switched between a low beam light distribution pattern PL and a light distribution pattern corresponding to the evaporation area, in response to the evaporation area detected by the detection unit 30. Furthermore, when high beam emission is selected by the light switch 120, the light distribution pattern of light emitted by the vehicle headlamp 1 is switched between a high beam light distribution pattern and a light distribution pattern corresponding to the evaporation area and the oncoming vehicle, in response to the evaporation area and the oncoming vehicle detected by the detection unit 30.

[0051] Next, a description will be given of the operation of switching between the high beam light distribution pattern and the light distribution pattern according to the evaporation area and the oncoming vehicle in the vehicle headlamp 1 of this embodiment. Fig. 7 is a diagram showing an example of a control flowchart of the control unit CO in this embodiment. As shown in Fig. 7, the control flow of this embodiment includes steps SP11 to SP17.

[0052] (Step SP11) A signal indicating emission of a high beam is input from the light switch 120 to the control unit CO, and the high beam is being emitted from the vehicle headlamp 1. In FIG. 7, this state is the start state. In this step, the control unit CO determines whether the detection unit 30 has detected an oncoming vehicle and whether the distance from the vehicle 100 to the oncoming vehicle is equal to or less than a predetermined distance, based on a signal input from the detection unit 30. This predetermined distance is, for example, 150 m, but is not particularly limited. As described above, when the detection unit 30 detects an oncoming vehicle, it outputs a signal indicating information related to the oncoming vehicle, such as the presence of the oncoming vehicle, its position relative to the vehicle 100, and the distance from the vehicle 100 to the oncoming vehicle, to the control unit CO. If the control unit CO receives a signal from the detection unit 30 indicating that the distance from the vehicle 100 to the oncoming vehicle is equal to or less than the predetermined distance, the control unit CO advances the control flow to step SP12. If the control unit CO does not receive this signal, the control unit CO advances the control flow to step SP13. Therefore, the control unit CO determines the next step based on the input signal.

[0053] (Step SP12) In this step, the control unit CO controls the second lamp unit 20 so that the light distribution pattern of the light emitted from the second lamp unit 20 corresponds to the oncoming vehicle detected by the detection unit 30. Then, the control unit CO advances the control flow to step SP14.

[0054] (Step SP13) In this step, the control unit CO controls the second lamp unit 20 so that light with a predetermined light distribution pattern when forming a high beam is emitted from the second lamp unit 20. Then, the control unit CO advances the control flow to step SP17.

[0055] (Step SP14) In this step, the control unit CO determines whether or not an evaporation area has been detected by the detection unit 30, based on a signal input from the detection unit 30. As described above, when the detection unit 30 detects an evaporation area, it outputs a signal to the control unit CO indicating information related to the evaporation area, such as the presence of the evaporation area and the position of the evaporation area relative to the vehicle 100. When this signal is input from the detection unit 30, the control unit CO determines that an evaporation area has been detected, and proceeds to step SP15. On the other hand, when this signal is not input, the control unit CO determines that an evaporation area has not been detected, and proceeds to step SP16.

[0056] A method for detecting an evaporated region by the detection unit 30 of this embodiment will be described. The detection unit 30 of this embodiment detects an evaporated region based on image data obtained by the camera 110 through binarization processing using a predetermined brightness value as a reference. FIG. 8 is a diagram schematically illustrating a portion of an example of image data obtained by the camera 110 through binarization processing. Specifically, FIG. 8 illustrates image data obtained by the camera 110 when a person is located in front of an oncoming vehicle. The person and their shadow in front of the oncoming vehicle are difficult to see due to evaporation caused by light from the headlights of the oncoming vehicle and light from the vehicle headlight 1 of the vehicle 100. In FIG. 8, the person 90 is indicated by a dotted line, a shadow 91 of the person 90 caused by light from the headlights of the oncoming vehicle is indicated by a two-dot chain line, and the low beam light distribution pattern PL is indicated by a thick line. The evaporated region is the area where the person 90 and their shadow 91 overlap with the area illuminated by the low beam.

[0057] A portion of an object that is difficult to see due to evaporation caused by light from the headlights of an oncoming vehicle tends to be perceived by the driver of the vehicle as a dark region sandwiched between regions brightened by the light from the headlights of the oncoming vehicle in the left-right direction. Furthermore, a shadow formed on the road surface or the like by an object blocking the light from the headlights of the oncoming vehicle also tends to be sandwiched between regions brightened by the light from the headlights of the oncoming vehicle. Furthermore, the width of these dark regions in the left-right direction tends to be smaller than, for example, the width of the oncoming vehicle in the left-right direction. In the binarization process of this embodiment, the predetermined luminance value is set so that such a portion of the object and the shadow of the object are extracted as a dark region sandwiched between bright regions in the left-right direction. Therefore, the luminance value of the bright region is equal to or greater than the predetermined luminance value, and the luminance value of the dark region is less than the predetermined luminance value. The predetermined luminance value is, for example, 3.0 cd / m 2 It may also be possible to use the following.

[0058] For ease of understanding, in FIG. 8 , bright area 51 is hatched with diagonal lines, and the area other than bright area 51 is dark area 52. Within bright area 51, area 51a is an area where the brightness is equal to or greater than a predetermined value due to light from the headlights of oncoming vehicles. Area 51b is an area where the brightness is equal to or greater than a predetermined value due to light from the headlights of oncoming vehicles reflected on the road surface. Area 51c is an area where the brightness is equal to or greater than a predetermined value due to light reflected from the center line. Area 51d is an area where the brightness is equal to or greater than a predetermined value due to light reflected from the outer lane line. In this embodiment, detection unit 30 detects area 55, which is located within the area of ​​dark area 52 illuminated by the low beam, is sandwiched between bright areas 51 with brightness values ​​equal to or greater than a predetermined value on the left and right, and has a width within a predetermined range in the left and right directions, as an evaporated area, and outputs a signal indicating information about area 55 to control unit CO. In FIG. 8 , area 55 is hatched with multiple dots. This predetermined range is, for example, equal to or less than the width of the oncoming vehicle in the left-right direction, but may also be equal to or less than the width between the pair of headlights of the oncoming vehicle, or may be equal to or less than the maximum width of region 51a in the left-right direction. Note that detection unit 30 may detect a region including region 55, for example, a region surrounding the entire outer edge of region 55, as the evaporation region.

[0059] The method for detecting the evaporated area by the detection unit 30 is not particularly limited. As described above, the evaporated area is an area in the area irradiated by the low beam that overlaps with at least one of an object that is difficult to see due to the evaporation phenomenon and the shadow of the object. Therefore, for example, if the vehicle 100 is equipped with a sensor device that can detect an object located in front of the vehicle 100, the detection unit 30 may detect an object located in front of an oncoming vehicle based on at least one of an image obtained by the camera 110 and a signal input from the sensor device, and detect an area including an area where the object overlaps with the area irradiated by the low beam from the viewpoint of the driver of the vehicle 100 as the evaporated area.

[0060] (Step SP15) In this step, the control unit CO controls the first lamp unit 10 so that the light distribution pattern of light emitted from the first lamp unit 10 corresponds to the region 55 detected by the detection unit 30. Specifically, the control unit CO refers to a table stored in the memory ME based on a signal indicating information about the region 55, and outputs a signal based on the power supplied to each light-emitting element 12a in the light distribution pattern corresponding to the region 55 to the power supply circuit 40. As a result, the power supplied to the light-emitting element 12a is adjusted by the driver of the power supply circuit 40, and light having a light distribution pattern corresponding to the region 55 is emitted from the first lamp unit 10. Then, the control unit CO advances the control flow to step SP17.

[0061] (Step SP16) In this step, the control unit CO controls the first lamp unit 10 so that a low beam is emitted from the first lamp unit 10. Then, the control unit CO advances the control flow to step SP17.

[0062] (Step SP17) In this step, the control unit CO determines whether the selection of the light switch 120 has changed based on the signal from the light switch 120. If the signal from the light switch 120 is the same as the signal at the start, the control unit CO returns the control flow to step SP11. On the other hand, if the signal from the light switch 120 is different from the signal at the start, the control unit CO stops the emission of light from the vehicle headlamp 1 and ends this control. Note that the control flow of the control unit CO is not limited to the control flow shown in FIG. 7. For example, in step SP13, the control unit CO may advance the control flow to step SP14.

[0063] In this way, the vehicle headlamp 1 of this embodiment changes the light distribution pattern of the light emitted from the first lamp unit 10 in response to the detection of an evaporation area by the detection unit 30, and changes the light distribution pattern of the light emitted from the second lamp unit 20 to a light distribution pattern that corresponds to the oncoming vehicle in response to the detection of an oncoming vehicle by the detection unit 30.

[0064] Fig. 9 is a diagram showing an example of a light distribution pattern of light emitted when the detection unit 30 detects an oncoming vehicle and an area 55 whose distance to the vehicle 100 is less than a predetermined distance while the light switch 120 is selected to emit high beams. In Fig. 9, a light distribution pattern 60 formed on a virtual vertical screen placed 25 m ahead of the vehicle 100 is shown by a thick line. Fig. 9 also shows the area 55, a person 90, and an oncoming vehicle 95.

[0065] The light distribution pattern 60 of this embodiment is formed by a light distribution pattern 70 of light emitted from the first lamp unit 10 and a light distribution pattern 80 of light emitted from the second lamp unit 20. In Fig. 9, the light distribution pattern 70 is indicated by a dashed line and the light distribution pattern 80 is indicated by a dashed two-dot line. For ease of understanding, these light distribution patterns 70 and 80 are shown slightly shifted from the light distribution pattern 60.

[0066] The light distribution pattern 70 is a light distribution pattern in which the light intensity in a predetermined region 75 of the low-beam light distribution pattern PL is reduced. Therefore, the total luminous flux of light from the first lamp unit 10 irradiating the predetermined region 75 in the light distribution pattern 70 is less than the total luminous flux of light from the first lamp unit 10 irradiating an area corresponding to the predetermined region 75 in the low-beam light distribution pattern PL. Furthermore, the light intensity is generally constant within the predetermined region 75 in the light distribution pattern 70. Note that the predetermined region 75 may be an area where no light is irradiated. In this way, the total luminous flux of light from the first lamp unit 10 is reduced in the predetermined region 75 compared to when the detection unit 30 does not detect the region 55. Meanwhile, the light intensity distribution in areas of the light distribution pattern 70 other than the predetermined region 75 is generally the same as the light intensity distribution in areas of the low-beam light distribution pattern PL other than the area corresponding to the predetermined region 75. The predetermined region 75 overlaps with at least a portion of the region 55. 9, the predetermined region 75 has a rectangular shape that overlaps the entire region 55 and includes a part of the low beam cutoff line CL1. Note that the shape of the predetermined region 75 is not particularly limited, and the predetermined region 75 may be separated from the cutoff lines CL1, CL2, and CL3.

[0067] The light distribution pattern 80 is a light distribution pattern in which the light intensity in a specific region 85 of a predetermined light distribution pattern when forming a high beam is reduced. Therefore, the total luminous flux of light from the second lamp unit 20 irradiating the specific region 85 is less than the total luminous flux of light from the second lamp unit 20 irradiating an area corresponding to the specific region 85 in the predetermined light distribution pattern. On the other hand, the light intensity distribution in areas of the light distribution pattern 80 other than the specific region 85 is approximately the same as the light intensity distribution in areas of the predetermined light distribution pattern other than the area corresponding to the specific region 85. The specific region 85 is approximately rectangular and overlaps the entire oncoming vehicle 95. This can reduce dazzle for the driver of the oncoming vehicle 95. Note that, from the perspective of reducing dazzle for the driver of the oncoming vehicle 95, the specific region 85 only needs to overlap with a viewing area through which the driver of the oncoming vehicle can see outside the vehicle, such as a windshield. Furthermore, within a specific region 85 in the light distribution pattern 80, the light intensity may or may not be generally constant, and the specific region 85 may be an area where light is not irradiated. In this embodiment, the specific region 85 includes the lower edge of the predetermined light distribution pattern, but it does not have to include the lower edge. Furthermore, the shape of the specific region 85 is not particularly limited.

[0068] Note that the switching operation between the low beam light distribution pattern and the light distribution pattern according to the evaporation area in the vehicle headlamp 1 of this embodiment differs from the switching operation between the high beam light distribution pattern and the light distribution pattern according to the evaporation area and oncoming vehicle 95 in that the second lamp unit 20 is not driven. The control flowchart of the control unit CO in this operation is, for example, the control flowchart shown in FIG. 7 with steps SP11, SP12, and SP13 eliminated. Therefore, a description of this operation will be omitted. Note that the control flowchart of the control unit CO may retain step SP11 but eliminate steps SP12 and SP13. Although not illustrated, the light distribution pattern according to the evaporation area is the light distribution pattern 60 shown in FIG. 9 with the light distribution pattern 80 eliminated.

[0069] As described above, the vehicle headlamp 1 of this embodiment includes the first lamp unit 10, the detection unit 30, and the control unit CO. The first lamp unit 10 is capable of changing the low beam light distribution pattern PL. The detection unit 30 detects the region 55 as an evaporation region that satisfies the requirements for evaporation to occur in the region illuminated by the low beam. When the detection unit 30 detects the region 55, the control unit CO controls the first lamp unit 10 so that the total luminous flux of light from the first lamp unit 10 irradiating a predetermined region 75 of the low beam light distribution pattern PL that overlaps at least a portion of the region 55 is reduced compared to when the detection unit 30 does not detect the region 55. Therefore, in the vehicle headlamp 1 of this embodiment, at least a portion of the region 55 is darkened compared to when the total luminous flux of light from the first lamp unit 10 irradiating the predetermined region 75 is not reduced, making it easier for the driver of the vehicle 100 to see at least a portion of the region 55. As described above, the evaporation region 55 is a region that overlaps with at least one of an object that has become difficult to see due to evaporation and the shadow of the object. Therefore, compared to the above case, the vehicle headlamp 1 of this embodiment can make objects such as people that are difficult to see due to evaporation easier to see, and can suppress a decrease in visibility ahead of the vehicle 100 caused by evaporation.

[0070] 9, in the vehicle headlamp 1 of this embodiment, the predetermined area 75 overlaps the entire area 55. Therefore, according to the vehicle headlamp 1 of this embodiment, the entire area 55 can be easily viewed.

[0071] In the vehicle headlamp 1 of this embodiment, as shown in FIG. 9 , the predetermined region 75 crosses the entire region 55 in the left-right direction. For example, if a pedestrian crossing the road becomes difficult to see due to evaporation, the relative position of the evaporation region corresponding to the pedestrian with respect to the vehicle 100 tends to change in the left-right direction. In the vehicle headlamp 1 of this embodiment, even if the relative position of the region 55 with respect to the vehicle 100 changes in the left-right direction, the predetermined region 75 and the region 55 can be made to overlap, thereby preventing, for example, the pedestrian crossing the road from becoming difficult to see. Note that even if the relative position of the region 55 with respect to the vehicle 100 changes in the left-right direction, from the perspective of overlapping the predetermined region 75 and the region 55, it is sufficient for the predetermined region 75 to cross at least a portion of the region 55 in the left-right direction. However, the predetermined region 75 may not cross the region 55 in the left-right direction, and for example, the entire predetermined region 75 and a portion of the region 55 may overlap each other.

[0072] 9, in the vehicle headlamp 1 of this embodiment, the predetermined area 75 is spaced apart from the lower edge of the low beam light distribution pattern PL. Therefore, according to the vehicle headlamp 1 of this embodiment, it is possible to suppress a decrease in visibility immediately in front of the vehicle 100 compared to when the predetermined area 75 includes the lower edge of the low beam light distribution pattern PL. Note that the predetermined area 75 may include the lower edge of the low beam light distribution pattern PL.

[0073] In the vehicle headlamp 1 of this embodiment, when the detection unit 30 detects the region 55 and the oncoming vehicle 95 as evaporation regions, the control unit CO controls the first lamp unit 10 so that the total luminous flux of light from the first lamp unit 10 irradiating a predetermined region 75 of the low-beam light distribution pattern PL that overlaps at least a portion of the region 55 is reduced compared to when the region 55 and the oncoming vehicle 95 are not detected. As the distance between the oncoming vehicle 95 and the vehicle 100 increases, evaporation due to the headlights of the oncoming vehicle 95 tends to be less likely to occur. Therefore, the vehicle headlamp 1 of this embodiment can prevent the low-beam light distribution pattern PL from changing in a case where evaporation due to the light from the headlights of the oncoming vehicle 95 and the light from the vehicle headlamp 1 of the vehicle 100 is less likely to occur. Note that the amount of reduction in the light from the first lamp unit 10 irradiating the predetermined region 75 may be increased stepwise or gradually as the distance between the vehicle 100 and the oncoming vehicle 95 decreases. In this way, the deterioration of visibility ahead of the vehicle 100 due to the evaporation phenomenon can be further suppressed.

[0074] (Second embodiment) Next, a second embodiment of the present invention will be described in detail. Components that are the same as or equivalent to those in the first embodiment will be assigned the same reference numerals, and redundant description will be omitted, unless otherwise specified. The vehicle headlamp 1 of this embodiment differs from the vehicle headlamp 1 of the first embodiment mainly in that the detection unit 30 detects an oncoming vehicle 95 without detecting an area 55. Therefore, the operation of the vehicle headlamp 1 of this embodiment differs from the operation of the vehicle headlamp 1 of the first embodiment, and the low beam light distribution pattern PL and the high beam light distribution pattern are switched to light distribution patterns corresponding to the oncoming vehicle 95 in response to the detection of the oncoming vehicle 95 by the detection unit 30.

[0075] First, the operation of switching the high beam light distribution pattern to a light distribution pattern according to the oncoming vehicle 95 will be described.

[0076] In this embodiment, the control unit CO changes the control of the first lamp unit 10 and the second lamp unit 20 depending on whether the detection unit 30 detects an oncoming vehicle 95 whose distance to the vehicle 100 is less than a predetermined distance when the light switch 120 selects high beam emission. The predetermined distance is, for example, 150 m. In this embodiment, the memory ME stores a table in which information related to the light distribution pattern formed by the light emitted from the first lamp unit 10 is associated with information related to the oncoming vehicle 95, and a table in which information related to the light distribution pattern formed by the light emitted from the second lamp unit 20 is associated with information related to the oncoming vehicle 95. When such an oncoming vehicle 95 is detected, the control unit CO refers to these tables and controls the first lamp unit 10 and the second lamp unit 20 so that the light distribution pattern of the emitted light changes from the high beam light distribution pattern to a light distribution pattern corresponding to the oncoming vehicle 95.

[0077] Fig. 10 is a diagram showing an example of a light distribution pattern of light emitted when the detection unit 30 detects an oncoming vehicle 95 whose distance to the vehicle 100 is less than a predetermined distance while high beam emission is selected by the light switch 120. In Fig. 10, a light distribution pattern 160 formed on a virtual vertical screen placed 25 m ahead of the vehicle 100 is indicated by a thick line.

[0078] The light distribution pattern 160 of this embodiment is formed by a light distribution pattern 170 of light emitted from the first lamp unit 10 and a light distribution pattern 180 of light emitted from the second lamp unit 20. In Fig. 10, the light distribution pattern 170 is indicated by a dashed line and the light distribution pattern 180 is indicated by a dashed line, and these light distribution patterns 170, 180 are indicated slightly shifted from the light distribution pattern 160.

[0079] Similar to the light distribution pattern 70 in the first embodiment, the light distribution pattern 170 is a light distribution pattern in which the light intensity in a predetermined region 175 of the low-beam light distribution pattern PL is reduced. The light intensity distribution in the predetermined region 175 of the light distribution pattern 170 is not particularly limited. For example, the predetermined region 175 may be a region where no light is irradiated. The predetermined region 175 overlaps with the oncoming vehicle 95 in the vertical direction and includes a portion of the low-beam cutoff line CL1. In this embodiment, the predetermined region 175 overlaps with the entire oncoming vehicle 95 in the vertical direction. The predetermined region 175 is separated from the lower edge of the low-beam light distribution pattern PL, and the maximum width of the predetermined region 175 in the horizontal direction is greater than the width of the oncoming vehicle 95 in the horizontal direction. The width of the predetermined region 175 at the upper end is greater than the width at the lower end, and the width of the predetermined region 175 decreases from the upper end to the lower end. The shape of the predetermined region 175 is not particularly limited. For example, the predetermined area 175 may include the lower edge of the low beam light distribution pattern PL, the left-right width of the predetermined area 175 may be smaller than the left-right width of the oncoming vehicle 95, and the width of the predetermined area 175 may be approximately constant in the up-down direction.

[0080] From the viewpoint of the driver of vehicle 100, the region of the low beam light distribution pattern PL that overlaps with oncoming vehicle 95 in the vertical direction generally overlaps with the region in front of oncoming vehicle 95. Furthermore, objects such as people that are difficult for the driver of vehicle 100 to see due to evaporation caused by the light from the headlights of oncoming vehicle 95 and the low beam of vehicle 100 tend to be located so as to cross the low beam cutoff line CL1 from the viewpoint of the driver, as described above. In this embodiment, the total luminous flux of light from the first lamp unit 10 that is irradiated onto a predetermined region 175 of the low beam light distribution pattern PL that overlaps with oncoming vehicle 95 in the vertical direction and includes a part of the low beam cutoff line CL1 is reduced. Therefore, even if an object such as a pedestrian is located in the area in front of the oncoming vehicle 95 and the object becomes difficult for the driver of the vehicle 100 to see due to evaporation caused by the light from the headlights of the oncoming vehicle 95 and the low beams of the vehicle 100, the visibility of the object can be prevented from decreasing compared to when the total luminous flux of light from the first lighting unit 10 irradiated onto the specified area 175 is not reduced.

[0081] Incidentally, the width in the left-right direction of the area where light from the headlights of the oncoming vehicle 95 is irradiated onto the road surface tends to be larger than the width of the oncoming vehicle 95 in the left-right direction. As described above, in this embodiment, the maximum width in the left-right direction of the predetermined area 175 is larger than the width of the oncoming vehicle 95 in the left-right direction. Therefore, compared to when the maximum width in the left-right direction is smaller than the width of the oncoming vehicle 95 in the left-right direction, the area where the area where light from the headlights of the oncoming vehicle 95 is irradiated onto the road surface and the predetermined area 175 overlap can be made larger. Therefore, according to the vehicle headlamp 1 of this embodiment, the range in which the reduction in visibility of the shadows of objects, etc., due to evaporation can be suppressed can be made wider than when the maximum width in the left-right direction is smaller than the width of the oncoming vehicle 95 in the left-right direction.

[0082] The light distribution pattern 180 is a light distribution pattern in which the light intensity in a specific region 185 of a predetermined light distribution pattern when forming a high beam is reduced. Therefore, the total luminous flux of light from the second lamp unit 20 irradiating the specific region 185 is less than the total luminous flux of light from the second lamp unit 20 irradiating an area corresponding to the specific region 185 in the predetermined light distribution pattern. On the other hand, the light intensity distribution in areas of the light distribution pattern 180 other than the specific region 185 is approximately the same as the light intensity distribution in areas of the predetermined light distribution pattern other than the area corresponding to the specific region 185. The specific region 185 overlaps with the oncoming vehicle 95 and is connected to the predetermined region 175. In this embodiment, the specific region 185 is approximately rectangular and overlaps with the entire oncoming vehicle 95. The specific region 185 includes a portion of the lower edge of the predetermined light distribution pattern of light emitted from the second lamp unit 20, and the lower end of the specific region 185 and the upper end of the specific region 175 overlap each other. Furthermore, the maximum width in the left-right direction of specific region 185 is smaller than the maximum width in the left-right direction of predetermined region 175. The shape of specific region 185 is not particularly limited. For example, specific region 185 may be separated from the lower edge of light distribution pattern 180, and the maximum width in the left-right direction of specific region 185 may be larger than the maximum width in the left-right direction of predetermined region 175.

[0083] As described above, the specific area 185 overlaps with the oncoming vehicle 95. Therefore, according to the vehicle headlamp 1 of this embodiment, it is possible to improve the visibility ahead of the vehicle 100 by using the light from the second lamp unit 20, while suppressing dazzling of the driver of the oncoming vehicle 95 by the light from the second lamp unit 20. The specific area 185 is connected to the predetermined area 175 that includes a portion of the cutoff line CL1. As described above, an object that becomes difficult to see due to evaporation tends to be located so as to cross the cutoff line CL1. Therefore, according to the vehicle headlamp 1 of this embodiment, it is possible to make a portion of this object overlap with the specific area 185, thereby suppressing the portion of this object from becoming difficult to see due to evaporation caused by the light from the second lamp unit 20 and the headlight of the oncoming vehicle 95.

[0084] Furthermore, the light distribution pattern of light emitted from the vehicle headlamp 1 may be a light distribution pattern as shown in FIG. 11. FIG. 11 is a diagram showing another example of a light distribution pattern of light emitted when the detection unit 30 detects an oncoming vehicle 95 whose distance to the vehicle 100 is less than a predetermined distance while the light switch 120 has selected to emit high beams. In FIG. 11, the predetermined region 175 is hatched with diagonal lines to facilitate understanding. The specific region 185 shown in FIG. 11 is the same as the specific region 185 shown in FIG. 10. However, the specific region 175 shown in FIG. 11 is different from the specific region 175 shown in FIG. 10. In this example, the entire specific region 175 and a part of the specific region 185 overlap each other. Furthermore, the left edge of predetermined region 175 and the left edge of specific region 185 are positioned on approximately the same straight line, the right edge of predetermined region 175 and the right edge of specific region 185 are positioned on approximately the same straight line, the lower edge of predetermined region 175 is approximately the same as the lower edge of specific region 185, and the upper edge of predetermined region 175 is the same as part of cutoff line CL1. Note that the lower edge of predetermined region 175 may be positioned below the lower edge of specific region 185. Even with predetermined region 175 of this example, even if an object such as a pedestrian is located in the area in front of oncoming vehicle 95 and the object becomes difficult for the driver of vehicle 100 to see due to evaporation caused by light from the headlights of oncoming vehicle 95 and the low beam of vehicle 100, a decrease in the visibility of the object can be suppressed compared to a case where the total luminous flux of light from first lamp unit 10 irradiating predetermined region 175 is not reduced.

[0085] Note that the switching operation between the low beam light distribution pattern and the light distribution pattern according to the oncoming vehicle 95 in the vehicle headlamp 1 of this embodiment differs from the switching operation between the high beam light distribution pattern and the light distribution pattern according to the oncoming vehicle 95 in that the second lamp unit 20 is not driven. Therefore, a description of this operation will be omitted. Also, although not illustrated, the light distribution pattern according to the oncoming vehicle 95 is the light distribution pattern 160 shown in FIGS. 10 and 11 with the light distribution pattern 180 removed.

[0086] Although the present invention has been described above using the above-mentioned embodiments as examples, the present invention is not limited to these.

[0087] For example, in the above embodiment, the vehicle headlamp 1 is described as being provided with the first lamp unit 10 and the second lamp unit 20 separately. However, the first lamp unit 10 and the second lamp unit 20 may be integrally formed. An example of the configuration of such a lamp unit is a configuration similar to that of the second lamp unit 20. In such a lamp unit, light emitted from some of the light-emitting elements 23 among the plurality of light-emitting elements 23 forms a light distribution pattern similar to that of light emitted from the first lamp unit 10, and light emitted from the other light-emitting elements 23 forms a light distribution pattern similar to that of light emitted from the second lamp unit 20. Furthermore, the configurations of the first lamp unit 10 and the second lamp unit 20 are not particularly limited. The first lamp unit 10 only needs to be able to change the light distribution pattern PL of the low beam, and the second lamp unit 20 only needs to be able to change the light distribution pattern of light irradiated onto an area at least a portion of which is located above the low beam and connected to the cut-off line.

[0088] In the first embodiment, the light distribution pattern of light from the second lamp unit 20 is changed when an oncoming vehicle 95 whose distance to the vehicle 100 is equal to or shorter than a predetermined distance is detected. However, the light distribution pattern of light from the second lamp unit 20 may be changed when an oncoming vehicle 95 is detected regardless of the distance between the vehicle 100 and the oncoming vehicle 95. In the second embodiment, the light distribution pattern of light from the first lamp unit 10 is changed when an oncoming vehicle 95 whose distance to the vehicle 100 is equal to or shorter than a predetermined distance is detected, or the light distribution patterns of the light from the first lamp unit 10 and the second lamp unit 20 are changed. However, the light distribution pattern of light from the first lamp unit 10 may be changed when an oncoming vehicle 95 is detected regardless of the distance between the vehicle 100 and the oncoming vehicle 95, or the light distribution patterns of the light from the first lamp unit 10 and the second lamp unit 20 may be changed. In addition, the detection unit 30 may be configured to detect a preceding vehicle along with the area 55 and the oncoming vehicle 95. In this case, the control unit CO may control the second lighting unit 20 so that when a preceding vehicle is detected, the total luminous flux of light from the second lighting unit 20 irradiated onto an area of ​​the light distribution pattern of the light emitted from the second lighting unit 20 that overlaps with the detected preceding vehicle is reduced compared to when a preceding vehicle is not detected.

[0089] In the first embodiment, an example was described in which the total luminous flux of light from the first lamp unit 10 irradiating the predetermined area 75 is reduced when an oncoming vehicle 95 and the area 55 whose distance to the vehicle 100 is less than or equal to a predetermined distance are detected, and the total luminous flux of light from the second lamp unit 20 irradiating the specific area 85 is reduced when an oncoming vehicle 95 whose distance to the vehicle 100 is less than or equal to the predetermined distance is detected. In the second embodiment, an example was described in which the total luminous flux of light from the first lamp unit 10 irradiating the predetermined area 175 is reduced and the total luminous flux of light from the second lamp unit 20 irradiating the specific area 185 is reduced when an oncoming vehicle 95 whose distance to the vehicle 100 is less than or equal to the predetermined distance is detected. However, the control unit CO may control the first lamp unit 10 and the second lamp unit 20 so that at least one of the amounts of dimming in the predetermined areas 75, 175 and the specific areas 85, 185 is increased as the distance between the vehicle 100 and the oncoming vehicle 95 decreases. The amount of dimming may be increased in stages or gradually as the distance between the vehicle 100 and the oncoming vehicle 95 decreases. For example, the amount of dimming may be increased in two stages, such that a second amount of dimming is greater when the distance is 50 m or less than a first amount of dimming when the distance is 150 m or less. The amount of dimming may also be increased in three or more stages. That is, the control unit CO may control the first lamp unit 10 and the second lamp unit 20 in this manner. This can suppress a decrease in forward visibility of the vehicle 100 due to evaporation while also suppressing a decrease in forward visibility due to a decrease in the amount of light from the first lamp unit 10. Furthermore, it can suppress dazzling of the driver of the oncoming vehicle 95 while suppressing a decrease in visibility of the oncoming vehicle 95.

[0090] According to the present invention, a vehicle headlamp is provided that can suppress a decrease in visibility ahead of the vehicle caused by evaporation, and can be used in fields such as vehicle headlamps for automobiles and the like.

Claims

1. A lighting unit that can change the low beam light distribution pattern, another lamp unit that is capable of changing a light distribution pattern of light that is at least partially positioned above the low beam and that is irradiated onto an area connected to a cutoff line of the low beam and forms a high beam together with the low beam; a detection unit that detects an oncoming vehicle; A control unit; Equipped with When the oncoming vehicle is detected by the detection unit in a state in which emission of the high beam is selected by a light switch, the control unit controls the lamp unit so that a total luminous flux of light from the lamp unit irradiated onto a predetermined area in the light distribution pattern of the low beam that overlaps with the oncoming vehicle in the vertical direction and includes a part of the cut-off line of the low beam is reduced compared to when the oncoming vehicle is not detected, and controls the other lamp unit so that a total luminous flux of light from the other lamp unit irradiated onto a specific area in the light distribution pattern of light emitted from the other lamp unit that overlaps with the oncoming vehicle and is connected to the predetermined area is reduced compared to when the oncoming vehicle is not detected. A vehicle headlamp characterized by:

2. When the distance from the vehicle to the oncoming vehicle exceeds a predetermined distance, the control unit controls the lamp unit so that the total luminous flux of the light from the lamp unit irradiated onto the predetermined area becomes the same as when the oncoming vehicle is not detected, and controls the other lamp unit so that the total luminous flux of the light from the other lamp unit irradiated onto the specific area becomes the same as when the oncoming vehicle is not detected.

2. The vehicle headlamp according to claim 1.

3. The control unit controls the lighting unit so that the light from the lighting unit is not irradiated onto the predetermined area.

2. The vehicle headlamp according to claim 1.

4. The control unit controls the other lighting unit so that light from the other lighting unit is not irradiated onto the specific area.

2. The vehicle headlamp according to claim 1.

5. The detection unit also detects a preceding vehicle, When the detection unit detects the preceding vehicle while the light switch is in a state where emission of the high beam is selected, the control unit controls the other lamp unit so that the total luminous flux of the light from the other lamp unit irradiated onto an area overlapping with the preceding vehicle in a light distribution pattern of the light emitted from the other lamp unit is reduced compared to when the preceding vehicle is not detected.

2. The vehicle headlamp according to claim 1.

6. The control unit controls the lamp unit and the other lamp unit so that the entire predetermined area and a part of the specific area overlap each other.

2. The vehicle headlamp according to claim 1.

7. The control unit controls the lamp unit and the other lamp unit so that a lower edge of the predetermined area is positioned lower than a lower edge of the specific area.

2. The vehicle headlamp according to claim 1.

8. The control unit controls the lamp unit and the other lamp unit so that at least one of an amount of dimming of the light from the lamp unit irradiated to the predetermined area and an amount of dimming of the light from the other lamp unit irradiated to the specific area gradually increases as the distance to the oncoming vehicle decreases.

2. The vehicle headlamp according to claim 1.

9. The control unit controls the lamp unit and the other lamp unit so that at least one of an amount of dimming of the light from the lamp unit irradiated to the predetermined area and an amount of dimming of the light from the other lamp unit irradiated to the specific area increases stepwise as the distance to the oncoming vehicle decreases.

2. The vehicle headlamp according to claim 1.

Images