JP7642682B2 - Vehicle headlights - Google Patents

Description

The present invention relates to a vehicle headlamp.

There are known vehicle headlamps, such as automobile headlights, that can change the light distribution pattern of the emitted light. The following Patent Document 1 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.

JP 2012-146621 A

However, if there is an object that the driver should be careful of, such as a person, at a position where the light from the headlights of the vehicle and the light from the headlights of an oncoming vehicle intersect, the driver may find it difficult to see the object. This phenomenon is sometimes called the evaporation phenomenon, and can occur even when the light emitted from the headlights of the vehicle is a low beam or the light distribution pattern for urban areas described in the above-mentioned Patent Document 1. For this reason, there is a demand to prevent the evaporation phenomenon from making it difficult for the driver to see objects that the driver should be careful of, such as people.

Therefore, the present invention aims to provide a vehicle headlamp that can suppress the reduction in visibility ahead of the vehicle caused by the evaporation phenomenon.

In order to achieve the above object, the vehicle headlamp of the present invention comprises a lamp unit capable of changing the light distribution pattern of the low beam, a detection unit which detects an evaporation area which satisfies the requirements for the evaporation phenomenon to occur in the area irradiated by the low beam, and a control unit, and the control unit controls the lamp unit so that when the evaporation area is detected by the detection unit, the total luminous flux of light from the lamp unit irradiated to a specified area of the low beam light distribution pattern which overlaps at least a portion of the evaporation area is less than when the evaporation area is not detected.

The evaporation area is an area in the area illuminated 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. In this vehicle headlamp, at least a portion of the evaporation area becomes darker than when the total luminous flux of light from the lamp unit illuminated to the specified area is not reduced, making it easier for the driver of the vehicle to see at least a portion of the evaporation area. Therefore, with this vehicle headlamp, compared to the above case, it is easier to see objects such as people that are difficult to see due to the evaporation phenomenon, and the decrease in visibility ahead of the vehicle caused by the evaporation phenomenon can be suppressed.

The specified area may overlap the entire evaporation area.

This configuration makes it easier to see the entire evaporation area.

The specified area may extend horizontally across at least a portion of the evaporation area.

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

The specified area may include a portion of the low beam cut-off line.

The specified area may be spaced apart from the lower edge of the low beam light distribution pattern.

By configuring in this way, it is possible to suppress the decrease in visibility immediately in front of the vehicle compared to when the specified area includes the lower edge of the low beam light distribution pattern.

The detection unit may detect as the evaporated area an area that is sandwiched between bright areas having a predetermined brightness value or more in the left-right direction and includes a dark area whose width in the left-right direction is within a predetermined range.

For example, a part of an object that is difficult to see due to evaporation caused by light from the headlights of an oncoming vehicle tends to be seen by the driver of the vehicle as a dark area sandwiched between areas that are brightened by the light from the headlights of the oncoming vehicle in the left-right direction. In addition, a shadow formed on the road surface or the like by an object blocking the light from the headlights of an oncoming vehicle also tends to be sandwiched between areas that are brightened by the light from the headlights of the oncoming vehicle. In addition, the left-right width of these dark areas tends to be smaller than the left-right width of the oncoming vehicle, for example. For this reason, in this vehicle headlight, the above-mentioned predetermined luminance value and the above-mentioned predetermined range can be set so that the above-mentioned bright area becomes an area brightened by the light from the headlights of the oncoming vehicle, and the above-mentioned dark area becomes a part of the object that is difficult to see due to evaporation or a part of the shadow of the object. In other words, the above-mentioned dark area can be made to become an evaporation area. For this reason, in this vehicle headlight, for example, the detection unit can detect the evaporation area by image processing image data obtained by capturing an image of the front of the vehicle.

The vehicle headlamp of the present invention further comprises a lamp unit capable of changing the low beam light distribution pattern, a detection unit which detects an oncoming vehicle, and a control unit, and the control unit controls the lamp unit so that when the oncoming vehicle is detected by the detection unit, the total luminous flux of light from the lamp 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 a part of the low beam cut-off line is reduced compared to when the oncoming vehicle is not detected.

From the viewpoint of the driver of the vehicle, the area of the low beam light distribution pattern that overlaps with the oncoming vehicle in the vertical direction generally overlaps with the area in front of the oncoming vehicle. In addition, objects such as people that are difficult for the driver of the vehicle to see due to the evaporation phenomenon caused by the light from the headlights of the oncoming vehicle and the low beam of the vehicle tend to be located so as to cross the low beam cutoff line from the driver's viewpoint. In this vehicle headlamp, the total luminous flux of light from the lamp unit that is irradiated to a predetermined area that overlaps with the oncoming vehicle in the vertical direction and includes a part 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 driver of the vehicle has difficulty seeing the object due to the evaporation phenomenon caused by the light from the headlights of the oncoming vehicle and the low beam of the vehicle, the visibility of the object can be suppressed from decreasing compared to when the total luminous flux of light from the lamp unit that is irradiated to the predetermined area is not reduced. Therefore, according to this vehicle headlamp, the decrease in visibility ahead of the vehicle caused by the evaporation phenomenon can be suppressed.

The above-mentioned vehicle headlamp may further include another lamp unit capable of changing the light distribution pattern of light irradiated to 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 lamp unit so that, when the oncoming vehicle is detected by the detection unit, the total luminous flux of light from the other lamp unit irradiated to 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 lamp unit and is connected to the specified area, compared to when the oncoming vehicle is not detected.

As described above, the specific area overlaps with an oncoming vehicle, and therefore the light from another lamp unit can improve visibility ahead of the vehicle while preventing the driver of the oncoming vehicle from being dazzled by the light from the other lamp unit. The specific area is also 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. For this reason, a portion of this object can be made to overlap with the specific area, preventing the portion of this object from becoming difficult to see due to evaporation caused by the light from the other lamp unit and the headlights of the oncoming vehicle.

As described above, the present invention provides a vehicle headlamp that can suppress the reduction in visibility ahead of the vehicle caused by the evaporation phenomenon.

1 is a plan view conceptually showing a vehicle equipped with a vehicle headlamp according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the up-down direction, which shows a schematic view of the first lamp unit shown in FIG. 1 . 3 is a front view showing the light source unit and the shade shown in FIG. 2; 2 is a cross-sectional view taken along the up-down direction, illustrating a second lamp unit illustrated in FIG. 1 . 5 is a front view showing the light distribution pattern forming section shown in FIG. 4; FIG. 4 is a diagram showing a light distribution pattern of a low beam. FIG. 4 is a diagram illustrating an example of a control flowchart of a control unit in the first embodiment. 1 is a diagram showing a schematic diagram of a portion of an example of image data obtained by performing binarization processing on image data obtained by a camera. FIG. 2 is a diagram illustrating an example of a light distribution pattern in the first embodiment. FIG. 11 is a diagram illustrating an example of a light distribution pattern in a second embodiment. FIG. 13 is a diagram showing another example of a light distribution pattern in the second embodiment.

Below, embodiments for implementing the vehicle headlamp according to the present invention are 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 of the present invention. Also, in the above attached drawings, the dimensions of each component may be exaggerated to facilitate understanding.

First Embodiment
Fig. 1 is a plan view conceptually showing a vehicle equipped with a vehicle headlamp according to the present embodiment. As shown in Fig. 1, a vehicle 100 according to the present embodiment includes a vehicle headlamp 1, a camera 110, and a light switch 120. The vehicle headlamp 1 according to the present 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 viewpoint of the driver of the vehicle 100, which is the host vehicle, and "left" means the left side from the viewpoint of the driver.

In this embodiment, the pair of lamp units 5 are shaped to be 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. For this reason, the following will describe one lamp unit 5, and a description of the other lamp unit 5 will be omitted.

The lamp section 5 of this embodiment comprises a first lamp unit 10 and a second lamp unit 20. The second lamp unit 20 is positioned closer to the center of the vehicle 100 than the first lamp unit 10.

2 is a cross-sectional view along the vertical direction, which shows a schematic view of the first lamp unit 10 shown in Fig. 1. As shown in Fig. 2, the first lamp unit 10 mainly comprises a light source unit 12, a shade 13, a projection lens 15, and a housing 16.

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 at the rear of the lamp housing 17 than the front, and the 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 the lamp chamber 10R, and the light source unit 12, the shade 13, and the projection lens 15 are housed in this lamp chamber 10R.

3 is a front view showing the light source unit 12 and the shade 13 shown in FIG. 2. As shown in FIG. 2 and FIG. 3, the light source unit 12 of this embodiment has 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. In addition, the light-emitting elements 12a are each capable of individually changing the amount of light emitted. For example, an LED (Light Emitting Diode) can be used as the light-emitting element 12a. Note that 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 of light-emitting elements 12a, the direction in which the light-emitting elements 12a are arranged, and the type of light-emitting element 12a are not particularly limited.

Such a light source unit 12 can form a desired light distribution pattern by selecting the light emitting element 12a that emits light. The light source unit 12 can also 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.

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 portion 12, and the fixing portion 13b is connected to the lower end. The fixing portion 13b extends rearward from the lower end of the light shielding portion 13a, and the rear end of the fixing portion 13b is fixed to the circuit board 12b. The upper edge of the light shielding portion 13a consists of a first edge portion 13e1, a second edge portion 13e2, and a third edge portion 13e3. The first edge portion 13e1 extends in a generally horizontal direction. The second edge portion 13e2 extends linearly from one end of the first edge portion 13e1 toward the opposite side to the first edge portion 13e1 side and downward. The third edge 13e3 extends in a substantially horizontal direction 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 a portion of the light emitted from the light source unit 12.

The projection lens 15 is a lens that adjusts the divergence angle of the incident light. In this embodiment, the projection lens 15 is a lens whose entrance surface and exit surface 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 part of the light emitted from the light source unit 12 is blocked by the shading portion 13a, and another part of the light emitted from the light source unit 12 enters the projection lens 15, and light having a predetermined light distribution pattern according to the shape of the shading portion 13a is emitted from the projection lens 15. In this way, 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 through the front cover 18. Note that this predetermined light distribution pattern is a light distribution pattern in which the light distribution pattern when a part of the light is blocked by the shading portion 13a is inverted vertically and horizontally.

Figure 4 is a cross-sectional view along the vertical direction, which shows a schematic view of the second lamp unit 20 shown in Figure 1. As shown in Figure 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 structure 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, and the light distribution pattern forming section 22 and the projection lens 25 are housed within the lamp chamber 20R formed by the housing 26.

5 is a front view showing the light distribution pattern forming unit 22 shown in FIG. 4. As shown in FIG. 4 and FIG. 5, the light distribution pattern forming unit 22 of this embodiment has 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 emitted. The 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, similar to the light source unit 12. 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 the light-emitting elements 23, the number of light-emitting elements 23 in each row of the light-emitting elements 23, the direction in which the light-emitting elements 23 are arranged, and the type of the light-emitting elements 23 are not particularly limited.

The projection lens 25 is a lens that adjusts the divergence angle of the incident light, similar to the projection lens 15. The projection lens 25 is disposed forward of the light distribution pattern forming section 22, and the light emitted from the light distribution pattern forming section 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 with a convex entrance surface and exit surface, and the rear focal point of the projection lens 25 is located on or near the light exit surface of any of the light-emitting elements 23 in the light distribution pattern forming section 22. The light emitted from the light distribution pattern forming section 22 enters the projection lens 15, and light of a predetermined light distribution pattern according to the amount of light emitted from the multiple light-emitting elements 23 is emitted from the projection lens 15. In this way, the light having the predetermined light distribution pattern emitted from the projection lens 25 is emitted from the second lamp unit 20 toward the front of the vehicle 100 through the front cover 28. This predetermined light distribution pattern is a light distribution pattern obtained by vertically and horizontally inverting the light distribution pattern before it enters the projection lens 15 .

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, the control unit CO may or may not use a machine learning device. As described below, the control unit CO controls the first lamp unit 10 and the second lamp unit 20.

A light switch 120 is connected to the control unit CO. In this embodiment, the light switch 120 is a switch that selects whether to emit a low beam, emit a high beam, or not emit 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 if not emitting light is selected. Details will be described later, but 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.

The camera 110 of this embodiment is attached to the front of the vehicle 100, captures images of the area in front of the vehicle 100 at a predetermined time interval, for example, at 1/30 second intervals, 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.

The detection unit 30 of this embodiment detects an evaporation area that satisfies the requirements for the evaporation phenomenon to occur in the area irradiated 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 the evaporation phenomenon in the area irradiated by the low beam and the shadow of the object. The object may be, for example, an object that the driver, such as a person, should be careful of. The method of detecting the evaporation area by the detection unit 30 will be described later. When the detection unit 30 detects an evaporation area, it 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 the evaporation area by the detection unit 30 is a case-by-case change of the output signal according to the image data obtained by the camera 110.

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 is a case-by-case analysis that changes the signal to be output 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.

The method of detecting an oncoming vehicle by the detection unit 30, the method of 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 points due to light emitted from the headlights of the oncoming vehicle are reflected in the image obtained by the camera 110. Therefore, the detection unit 30 may detect the oncoming vehicle based on the presence or absence of the reflection of the pair of light points. 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. In addition, when 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 obtained by the camera 110 and the signal input from the sensor device. Examples of the sensor device include millimeter wave radar and lidar. In addition, the distance from the vehicle 100 to the oncoming vehicle may be calculated by a calculation unit other than the detection unit 30.

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

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.

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, such as 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, such as 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.

Next, we will explain the low beam emitted from the vehicle headlamp 1.

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 the 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.

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

The upper edge of the low beam light distribution pattern PL in this embodiment is composed of cutoff lines CL1, CL2, and CL3. The cutoff line CL1 extends horizontally to the right from the 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 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 the elbow point EP. Such an upper edge of the low beam light distribution pattern PL corresponds to the shape of the upper end of the light blocking portion 13a. In countries and regions where vehicles are driven 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.

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.

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

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

(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 emitted from the vehicle headlamp 1. In FIG. 7, this state is the start state. In this step, the control unit CO judges whether or not an oncoming vehicle is detected by the detection unit 30 and 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, 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. When the control unit CO receives a signal indicating that the distance from the vehicle 100 to the oncoming vehicle is equal to or less than a predetermined distance from the detection unit 30, the control unit CO advances the control flow to step SP12, and when this signal is not received, the control unit CO advances the control flow to step SP13. For this reason, the control unit CO judges the step to be advanced to by dividing the cases according to the input signal.

(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.

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

(Step SP14)
In this step, the control unit CO judges whether or not the evaporation area has been detected by the detection unit 30 based on the signal input from the detection unit 30. As described above, when the detection unit 30 detects an evaporation area, it 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. When this signal is input from the detection unit 30, the control unit CO judges that the evaporation area has been detected, and advances the control flow to step SP15. On the other hand, when this signal is not input, the control unit CO judges that the evaporation area has not been detected, and advances the control flow to step SP16.

A method for detecting an evaporated area by the detection unit 30 of this embodiment will be described. The detection unit 30 of this embodiment detects an evaporated area based on image data obtained by performing binarization processing on image data obtained by the camera 110 based on a predetermined luminance value. FIG. 8 is a diagram showing a part of an example of image data obtained by performing binarization processing on image data obtained by the camera 110. Specifically, FIG. 8 is a diagram showing image data obtained by performing binarization processing on image data obtained by the camera 110 when a person is located in front of an oncoming vehicle, and the person located in front of the oncoming vehicle and the shadow of the person are in a state where they are difficult to see due to the evaporation phenomenon caused by the light from the headlight of the oncoming vehicle and the light from the vehicle headlight 1 of the vehicle 100. In FIG. 8, such a person 90 is shown by a dotted line, the shadow 91 of the person 90 caused by the light from the headlight of the oncoming vehicle is shown by a two-dot chain line, and the light distribution pattern PL of the low beam is shown by a thick line. The evaporated area is an area where the person 90 and the shadow 91 overlap with the area irradiated by the low beam.

A part of an object that is difficult to see due to evaporation caused by light from the headlights of an oncoming vehicle tends to be seen by the driver of the vehicle as a dark area sandwiched between areas brightened by the light from the headlights of the oncoming vehicle in the left-right direction. In addition, a shadow formed on the road surface or the like by an object blocking the light from the headlights of an oncoming vehicle also tends to be sandwiched between areas brightened by the light from the headlights of the oncoming vehicle. In addition, the width of these dark areas in the left-right direction tends to be smaller than the width of the oncoming vehicle in the left-right direction, for example. In the above binarization process in this embodiment, the above-mentioned predetermined luminance value is set so that such a part of the object and the shadow of the object are extracted as a dark area sandwiched between bright areas in the left-right direction. For this reason, the luminance value in the bright area is equal to or greater than the predetermined luminance value, and the luminance value in the dark area is less than the predetermined luminance value, and the predetermined luminance value may be, for example, 3.0 cd/ ^m2 .

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

The method of detecting the evaporated area by the detection unit 30 is not particularly limited. As described above, the evaporated area is an area overlapping with at least one of an object that is difficult to see due to the evaporation phenomenon and the shadow of the object in the area irradiated with the low beam. For this reason, for example, when 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 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 area irradiated with the low beam and this object overlap from the viewpoint of the driver of the vehicle 100 as the evaporated area.

(Step SP15)
In this step, the control unit CO controls the first lamp unit 10 so that the light distribution pattern of the 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 related to 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 in the 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.

(Step SP16)
In this step, the control unit CO controls the first lamp unit 10 so as to emit a low beam from the first lamp unit 10. Then, the control unit CO advances the control flow to step SP17.

(Step SP17)
In this step, the control unit CO judges 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.

In this manner, 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 appropriate for the oncoming vehicle in response to the detection of an oncoming vehicle by the detection unit 30.

Figure 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 area 55 whose distance to the vehicle 100 is less than a predetermined distance when high beam emission is selected by the light switch 120. In Figure 9, a light distribution pattern 60 formed on a virtual vertical screen located 25 m ahead of the vehicle 100 is shown by a thick line. Figure 9 also shows area 55, a person 90, and an oncoming vehicle 95.

The light distribution pattern 60 of this embodiment is formed by a light distribution pattern 70 of the light emitted from the first lamp unit 10 and a light distribution pattern 80 of the light emitted from the second lamp unit 20. In Fig. 9, the light distribution pattern 70 is shown by a dashed line, and the light distribution pattern 80 is shown by a dashed line. To facilitate understanding, these light distribution patterns 70 and 80 are shown slightly shifted from the light distribution pattern 60.

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 the light from the first lamp unit 10 irradiated to the predetermined region 75 in the light distribution pattern 70 is less than the total luminous flux of the light from the first lamp unit 10 irradiated to the region corresponding to the predetermined region 75 in the low beam light distribution pattern PL. In addition, the light intensity is generally constant in the predetermined region 75 in the light distribution pattern 70. The predetermined region 75 may be an area where light is not irradiated. In this way, the total luminous flux of the light from the first lamp unit 10 is reduced in the predetermined region 75 compared to when the region 55 is not detected by the detection unit 30. On the other hand, the light intensity distribution in the light distribution pattern 70 in the region other than the predetermined region 75 is generally the same as the light intensity distribution in the region other than the region corresponding to the predetermined region 75 in the low beam light distribution pattern PL. This predetermined region 75 overlaps at least a part of the region 55. 9, the predetermined region 75 is rectangular and overlaps with the entire region 55, and includes a part of the low beam cutoff line CL1. 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.

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 the light from the second lamp unit 20 irradiated to the specific region 85 is less than the total luminous flux of the light from the second lamp unit 20 irradiated to the region corresponding to the specific region 85 in the predetermined light distribution pattern. On the other hand, the light intensity distribution in the region other than the specific region 85 of the light distribution pattern 80 is approximately the same as the light intensity distribution in the region other than the region corresponding to the specific region 85 of the predetermined light distribution pattern. The specific region 85 is approximately rectangular and overlaps with the entire oncoming vehicle 95. Therefore, it is possible to suppress dazzling of the driver of the oncoming vehicle 95. In addition, from the viewpoint of suppressing dazzling of the driver of the oncoming vehicle 95, the specific region 85 may overlap with a viewing portion for the driver of the oncoming vehicle to view the outside of the vehicle, for example, a front window. In addition, within a specific region 85 in the light distribution pattern 80, the light intensity may be approximately constant or may not be 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 does not have to include the lower edge. In addition, the shape of the specific region 85 is not particularly limited.

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 the 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. For this reason, the description of this operation is omitted. The control flowchart of the control unit CO may retain step SP11 and 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.

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 can change the light distribution pattern PL of the low beam. The detection unit 30 detects the region 55 as an evaporation region that satisfies the requirements for the evaporation phenomenon to occur in the region irradiated with 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 the light from the first lamp unit 10 irradiated to a predetermined region 75 of the low beam light distribution pattern PL that overlaps with at least a part of the region 55 is reduced compared to when the region 55 is not detected. Therefore, in the vehicle headlamp 1 of this embodiment, at least a part of the region 55 becomes darker than when the total luminous flux of the light from the first lamp unit 10 irradiated to the predetermined region 75 is not reduced, making it easier for the driver of the vehicle 100 to see at least a part of the region 55. As described above, the evaporation region 55 is a region 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, according to the vehicle headlamp 1 of the present embodiment, compared to the above case, it is possible to make an object, such as a person, that is difficult to see due to the evaporation phenomenon more visible, and it is possible to suppress a decrease in visibility ahead of the vehicle 100 caused by the evaporation phenomenon.

In the vehicle headlamp 1 of this embodiment, as shown in Figure 9, the predetermined area 75 overlaps with the entire area 55. Therefore, according to the vehicle headlamp 1 of this embodiment, it is possible to make the entire area 55 easily visible.

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, when a pedestrian crossing the road is difficult to see due to the evaporation phenomenon, 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, and for example, it is possible to suppress 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 viewpoint of making the predetermined region 75 and the region 55 overlap, it is sufficient that the predetermined region 75 crosses at least a part of the region 55 in the left-right direction. However, the predetermined region 75 does not cross the region 55 in the left-right direction, and for example, the entire predetermined region 75 and a part of the region 55 may overlap each other.

In the vehicle headlamp 1 of this embodiment, as shown in Fig. 9, the predetermined area 75 is separated from the lower edge of the low beam light distribution pattern PL. Therefore, according to the vehicle headlamp 1 of this embodiment, the decrease in visibility immediately in front of the vehicle 100 can be suppressed compared to the case where 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.

In the vehicle headlamp 1 of this embodiment, when the detection unit 30 detects the region 55 and the oncoming vehicle 95 as the evaporation region, the control unit CO controls the first lamp unit 10 so that the total luminous flux of the light from the first lamp unit 10 irradiated to the predetermined region 75 of the low beam light distribution pattern PL that overlaps at least a part of the region 55 is reduced compared to when the region 55 and the oncoming vehicle 95 are not detected. When the distance from the oncoming vehicle 95 to the vehicle 100 becomes long, the evaporation phenomenon caused by the headlamp of the oncoming vehicle 95 tends to be less likely to occur. Therefore, according to the vehicle headlamp 1 of this embodiment, it is possible to suppress the change in the low beam light distribution pattern PL in a case where the evaporation phenomenon due to the light from the headlamp 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 irradiated to the predetermined region 75 may be increased stepwise or gradually according to the decrease in the distance between the vehicle 100 and the oncoming vehicle 95. In this way, the decrease in visibility ahead of the vehicle 100 caused by the evaporation phenomenon can be further suppressed.

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 given the same reference symbols and will not be described again unless otherwise specified. The vehicle headlamp 1 of this embodiment is mainly different from the vehicle headlamp 1 of the first embodiment in that the detection unit 30 detects an oncoming vehicle 95 without detecting the region 55. Therefore, the operation of the vehicle headlamp 1 of this embodiment is different 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 a light distribution pattern corresponding to the oncoming vehicle 95 in response to the detection of the oncoming vehicle 95 by the detection unit 30.

First, we will explain the operation of switching the high beam light distribution pattern to a light distribution pattern corresponding to an oncoming vehicle 95.

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 or not 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 the emission of high beams. 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 an oncoming vehicle 95 as described above 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 light distribution pattern of the high beam to a light distribution pattern corresponding to the oncoming vehicle 95.

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 the light switch 120 is in a state where high beam emission is selected. In FIG. 10, a light distribution pattern 160 formed on a virtual vertical screen located 25 m ahead of the vehicle 100 is shown by a thick line.

The light distribution pattern 160 of this embodiment is formed by a light distribution pattern 170 of the light emitted from the first lamp unit 10 and a light distribution pattern 180 of the light emitted from the second lamp unit 20. In FIG. 10, the light distribution pattern 170 is shown by a dashed line, and the light distribution pattern 180 is shown by a dashed line. These light distribution patterns 170 and 180 are shown slightly shifted from the light distribution pattern 160.

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, similar to the light distribution pattern 70 in the first embodiment. The light intensity distribution in the predetermined region 175 in the light distribution pattern 170 is not particularly limited, and for example, the predetermined region 175 may be a region where light is not irradiated. This predetermined region 175 overlaps with the oncoming vehicle 95 in the vertical direction and includes a part 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. In addition, the predetermined region 175 is separated from the lower edge of the low beam light distribution pattern PL, and the maximum width in the left-right direction of the predetermined region 175 is larger than the width of the oncoming vehicle 95 in the left-right direction. In addition, the left-right width at the upper end of the predetermined region 175 is larger than the width at the lower end, and the width of the predetermined region 175 becomes smaller from the upper end to the lower end. The shape of the predetermined region 175 is not particularly limited. For example, the specified area 175 may include the lower edge of the low beam light distribution pattern PL, the left-right width of the specified area 175 may be smaller than the left-right width of the oncoming vehicle 95, and the width of the specified area 175 may be generally constant in the up-down direction.

From the viewpoint of the driver of the vehicle 100, the area of the low beam light distribution pattern PL that overlaps with the oncoming vehicle 95 in the vertical direction generally overlaps with the area in front of the oncoming vehicle 95. In addition, objects such as people that are difficult for the driver of the vehicle 100 to see due to the evaporation phenomenon caused by the light from the headlights of the oncoming vehicle 95 and the low beam of the vehicle 100 tend to be located so as to cross the low beam cutoff line CL1 from the viewpoint of the driver. In this embodiment, as described above, the total luminous flux of light from the first lamp unit 10 that is irradiated to a predetermined area 175 that overlaps with the oncoming vehicle 95 in the vertical direction and includes a part of the low beam cutoff line CL1 in the low beam light distribution pattern PL 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 driver of the vehicle 100 has difficulty seeing the object 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 a case where the total luminous flux of light from the first lighting unit 10 irradiated to the specified area 175 is not reduced.

However, the width in the left-right direction of the area where the 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 specified 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 the light from the headlights of the oncoming vehicle 95 is irradiated onto the road surface and the specified area 175 overlap can be made larger. Therefore, according to the vehicle headlamp 1 of this embodiment, the range in which the visibility of the shadow of an object, etc., can be suppressed from decreasing due to the evaporation phenomenon can be made wider, 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 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 the light from the second lamp unit 20 irradiated to the specific region 185 is less than the total luminous flux of the light from the second lamp unit 20 irradiated to the region corresponding to the specific region 185 in the predetermined light distribution pattern. On the other hand, the light intensity distribution in the region other than the specific region 185 of the light distribution pattern 180 is approximately the same as the light intensity distribution in the region other than the region corresponding to the specific region 185 of the predetermined light distribution pattern. The specific region 185 overlaps with the oncoming vehicle 95 and is connected to the specified region 175. In this embodiment, the specific region 185 is approximately rectangular and overlaps with the entire oncoming vehicle 95. In addition, the specific region 185 includes a part of the lower edge of the predetermined light distribution pattern of the 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. In addition, the maximum width in the left-right direction of the specific region 185 is smaller than the maximum width in the left-right direction of the predetermined region 175. The shape of the specific region 185 is not particularly limited. For example, the specific region 185 may be separated from the lower edge of the light distribution pattern 180, and the maximum width in the left-right direction of the specific region 185 may be larger than the maximum width in the left-right direction of the predetermined region 175.

As described above, the specific area 185 overlaps with the oncoming vehicle 95. Therefore, according to the vehicle headlamp 1 of this embodiment, the light from the second lamp unit 20 can improve the visibility ahead of the vehicle 100 while suppressing the driver of the oncoming vehicle 95 from being dazzled by the light from the second lamp unit 20. The specific area 185 is connected to the predetermined area 175 including a part of the cutoff line CL1. As described above, an object that becomes difficult to see due to the evaporation phenomenon tends to be located so as to cross the cutoff line CL1. Therefore, according to the vehicle headlamp 1 of this embodiment, a part of this object can be made to overlap with the specific area 185, and it is possible to suppress the part of this object from becoming difficult to see due to the evaporation phenomenon caused by the light from the second lamp unit 20 and the light from the headlamp of the oncoming vehicle 95.

The light distribution pattern of the 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 the light emitted when the detection unit 30 detects an oncoming vehicle 95 whose distance to the vehicle 100 is less than a predetermined distance in a state in which the light switch 120 selects emission of high beams. In FIG. 11, the predetermined area 175 is hatched with diagonal lines to facilitate understanding. The specific area 185 shown in FIG. 11 is the same as the specific area 185 shown in FIG. 10. On the other hand, the specific area 175 shown in FIG. 11 is different from the specific area 175 shown in FIG. 10. In this example, the entire specific area 175 and a part of the specific area 185 overlap each other. In addition, the left edge of the predetermined region 175 and the left edge of the specific region 185 are located on approximately the same straight line, the right edge of the predetermined region 175 and the right edge of the specific region 185 are located on approximately the same straight line, the lower edge of the predetermined region 175 is approximately the same as the lower edge of the specific region 185, and the upper edge of the predetermined region 175 is the same as a part of the cutoff line CL1. The lower edge of the predetermined region 175 may be located below the lower edge of the specific region 185. Even in the case of the predetermined region 175 of this example, even if an object such as a pedestrian is located in the region in front of the oncoming vehicle 95 and the object becomes difficult for the driver of the vehicle 100 to see due to the evaporation phenomenon caused by the light from the headlights of the oncoming vehicle 95 and the low beam of the vehicle 100, the visibility of the object can be suppressed from decreasing compared to the case where the total luminous flux of the light from the first lamp unit 10 irradiated to the predetermined region 175 is not reduced.

The switching operation between the low beam light distribution pattern and the light distribution pattern corresponding 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 corresponding 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 an illustrated description will be omitted, the light distribution pattern corresponding to the oncoming vehicle 95 is the light distribution pattern 160 shown in Figures 10 and 11 with the light distribution pattern 180 eliminated.

The present invention has been described above using the above embodiments as examples, but the present invention is not limited to these.

For example, in the above embodiment, the vehicle headlamp 1 is 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, a light distribution pattern similar to that of the light emitted from the first lamp unit 10 is formed by the light emitted from some of the light-emitting elements 23 among the plurality of light-emitting elements 23, and a light distribution pattern similar to that of the light emitted from the second lamp unit 20 is formed by the light emitted from the other light-emitting elements 23. In addition, 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 the light irradiated to an area at least a part of which is located above the low beam and connected to the cutoff line.

In the first embodiment, the light distribution pattern of the light from the second lamp unit 20 is changed when an oncoming vehicle 95 whose distance to the vehicle 100 is equal to or less than a predetermined distance is detected. However, the light distribution pattern of the 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 the light from the first lamp unit 10 is changed, or the light distribution patterns of the light from the first lamp unit 10 and the light from the second lamp unit 20 are changed when an oncoming vehicle 95 whose distance to the vehicle 100 is equal to or less than a predetermined distance is detected. However, the light distribution pattern of the light from the first lamp unit 10 is changed, or the light distribution patterns of the light from the first lamp unit 10 and the light from the second lamp unit 20 are changed when an oncoming vehicle 95 is detected regardless of the distance between the vehicle 100 and the oncoming vehicle 95. In addition, the detection unit 30 may be configured to detect a preceding vehicle together with the region 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 to an area in 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.

In the first embodiment, when an oncoming vehicle 95 and an area 55 whose distance to the vehicle 100 is equal to or less than a predetermined distance are detected, the total luminous flux of the light from the first lamp unit 10 irradiated to the predetermined area 75 is reduced, and when an oncoming vehicle 95 whose distance to the vehicle 100 is equal to or less than a predetermined distance is detected, the total luminous flux of the light from the second lamp unit 20 irradiated to the specific area 85 is reduced. In the second embodiment, when an oncoming vehicle 95 whose distance to the vehicle 100 is equal to or less than a predetermined distance is detected, the total luminous flux of the light from the first lamp unit 10 irradiated to the specific area 175 is reduced, and the total luminous flux of the light from the second lamp unit 20 irradiated to the specific area 185 is reduced. 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 dimming amounts in the predetermined areas 75, 175 and the specific areas 85, 185 is increased in accordance with the decrease in the distance between the vehicle 100 and the oncoming vehicle 95. The dimming amount may be increased stepwise or gradually according to the decrease in the distance between the vehicle 100 and the oncoming vehicle 95. For example, the dimming amount may be increased in two steps so that the second dimming amount when the distance is 50 m or less is greater than the first dimming amount when the distance is 150 m or less. The dimming amount may be increased in three or more steps. That is, the control unit CO may control the first lamp unit 10 and the second lamp unit 20 in this way. In this way, the decrease in the visibility ahead of the vehicle 100 caused by the evaporation phenomenon can be suppressed while the decrease in the visibility ahead of the vehicle 100 due to the decrease in the amount of light from the first lamp unit 10 can be suppressed. In addition, the decrease in the visibility of the oncoming vehicle 95 can be suppressed while suppressing the driver of the oncoming vehicle 95 from being dazzled.

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

Claims (7)

A lighting unit that can change the low beam light distribution pattern,
a detection unit for detecting an evaporation region that satisfies a condition for an evaporation phenomenon to occur in the region irradiated with the low beam;
A control unit;
Equipped with
The control unit controls the lighting unit so that, when the evaporation area is detected by the detection unit, the total luminous flux of light from the lighting unit irradiated to a predetermined area of the low beam light distribution pattern that overlaps at least a portion of the evaporation area is reduced compared to when the evaporation area is not detected. The vehicle headlamp according to claim 1 , wherein the predetermined area overlaps the entire evaporation area. 3. The vehicle headlamp according to claim 1, wherein the predetermined area crosses at least a part of the evaporation area in the left-right direction. 4. The vehicle headlamp according to claim 1, wherein the predetermined area includes a part of the cut-off line of the low beam. 5. The vehicle headlamp according to claim 1, wherein the predetermined area is spaced apart from a lower edge of the low beam light distribution pattern. The vehicle headlamp according to any one of claims 1 to 5, characterized in that the detection unit detects as the evaporated region a region that is sandwiched in the left-right direction by bright regions having a predetermined luminance value or more and that includes a dark region whose left-right width is within a predetermined range. A lighting unit that can change the low beam light distribution pattern,
Another lamp unit capable of changing a light distribution pattern of light irradiated to an area at least a part of which is located above the low beam and connected to a cutoff line of the low beam;
A detection unit that detects an oncoming vehicle;
A control unit;
Equipped with
The control unit controls the lamp unit so that, when the oncoming vehicle is detected by the detection unit, a total luminous flux amount of light from the lamp unit irradiated to 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 amount of light from the other lamp unit irradiated to 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:

Images