JP7458820B2 - Vehicle headlights - Google Patents

Description

The present invention relates to a vehicle headlamp.

Conventionally, vehicle headlight systems have been known that detect light-emitting objects that emit their own light, such as a vehicle in front, and retroreflective objects, such as road signs, that do not emit light themselves but retroreflect light at a predetermined spread angle. . Such a vehicle headlamp system is disclosed in Patent Document 1. The vehicle headlamp system disclosed in Patent Document 1 uses a headlamp that alternately repeats irradiation and non-irradiation, photographs the front of the vehicle during irradiation and non-irradiation, and generates images during irradiation. and an imaging unit that generates a non-irradiation image. In addition, the vehicle headlamp system determines the high-brightness area located in the non-irradiation image as a light-emitting object, and recursively identifies the high-brightness area located in the irradiation image but not in the non-irradiation image. It includes a detection unit that determines it as a reflective object.

Japanese Patent Application Publication No. 2011-110999

In the vehicle headlamp system disclosed in Patent Document 1, information on objects such as light-emitting objects and retroreflective objects detected by the detection unit is used to control the light distribution from the own vehicle's headlights. be done. When the light distribution is controlled and the light from the vehicle's headlights illuminates an object such as a road sign located in front of the vehicle, a portion of the light is reflected from the object. Sometimes I go to the car. There is a concern that the shorter the distance between the vehicle and the object, the more glare the reflected light directed toward the vehicle may cause to the driver of the vehicle. As a result, there is a concern that visibility for the driver may be reduced.

The present invention aims to provide a vehicle headlamp that can suppress a decrease in visibility for the driver.

In order to solve the above problems, the vehicle headlamp of the present invention uses information from a lamp installed in the front part of the vehicle and a detection device that detects an object located in front of the vehicle. a calculation unit that calculates a distance between the vehicle and the object; a determination unit that determines whether the object satisfies predetermined requirements based on the distance calculated by the calculation unit; a control unit that controls the lamp, and the control unit controls at least a portion of the object from the lamp when the determination unit determines that the object satisfies the predetermined requirements. The lighting device is characterized in that the lighting device is controlled such that the amount of light emitted toward the lighting device decreases as the distance calculated by the calculation unit becomes shorter.

When the light from the vehicle headlight of the own vehicle illuminates at least a portion of an object such as a road sign located in front of the own vehicle, a portion of the light travels from the object to the own vehicle as reflected light. Sometimes. There is a concern that the shorter the distance between the vehicle and the object, the more glare the reflected light directed toward the vehicle may cause to the driver of the vehicle. Here, if the predetermined requirement indicates that the distance between the vehicle and the object is less than a predetermined distance, then in the vehicle headlamp of the present invention, the distance between the vehicle and the object is less than a predetermined distance. The amount of light when the distance is less than the predetermined distance decreases as the distance between the vehicle and the object becomes shorter. In this way, when the amount of light decreases as the distance between the vehicle and the object decreases, the intensity of the reflected light toward the own vehicle decreases more than when the amount of light does not decrease as the distance between the vehicle and the object decreases. Can be suppressed. As a result, even if the reflected light travels toward the own vehicle, glare from being applied to the driver of the own vehicle can be suppressed. Therefore, according to this vehicle headlamp, it is possible to suppress a decrease in driver's visibility.

Further, the control unit may control the amount of light emitted from the lamp toward at least a portion of the target object when the determination unit determines that the target object satisfies the predetermined requirements. a standard indicating a light amount of reference light indicating light emitted from the lamp toward at least a portion of the object when the determination unit determines that the object does not satisfy the predetermined requirements; It is preferable to control the lamp so that the amount of light is less than the amount of light.

Here, suppose that the predetermined requirement indicates that the distance between the vehicle and the target object is less than a predetermined distance, and the determination unit determines that the target object satisfies the predetermined requirement. A comparison with a case where the object is determined to not meet predetermined requirements by the department will be explained. When the amount of light in a state where the object meets the predetermined requirements is less than the reference amount of light in a state where the object does not meet the predetermined requirements, the amount of light reflected toward the vehicle will be lower than when the amount of light does not become less than the reference amount. The intensity of light can be suppressed. As a result, even if the reflected light travels toward the own vehicle, glare from being applied to the driver of the own vehicle can be suppressed. Therefore, according to this vehicle headlamp, it is possible to suppress a decrease in driver's visibility.

Further, it is preferable that the control unit controls the lamp so that the amount of light gradually decreases.

This vehicle headlamp suppresses sudden changes in the amount of light. Therefore, this vehicle headlamp can suppress a decrease in the visibility of the driver of the vehicle caused by sudden changes. Furthermore, this vehicle headlamp can make it easier for the driver's eyes to naturally become accustomed to the brightness ahead of the vehicle compared to a case where the amount of light does not decrease gradually. Therefore, this vehicle headlamp can suppress a decrease in the visibility of the driver of the vehicle.

Alternatively, it is preferable that the control unit controls the lamp so that the amount of light decreases in stages.

In this vehicle headlamp, the control unit may control the lamp at the timing when the amount of light gradually decreases. Therefore, the burden on the control unit can be reduced compared to the case where the amount of light does not decrease stepwise.

Further, the information indicates a ratio of the object in a photographed image in front of the vehicle photographed by the detection device and an amount of change in the size of the object in the photographed image, and the calculation unit It is preferable that the distance is calculated based on the amount of change.

In this vehicle headlamp, the shorter the distance between the vehicle and the object, the closer the vehicle is to the object, so the proportion of the object in the captured image and the size of the object in the captured image change over time. The quantity becomes larger. The larger the ratio and the amount of change, the smaller the amount of light, and the intensity of the reflected light toward the own vehicle can be suppressed. As a result, even if the reflected light travels toward the own vehicle, glare on the driver of the own vehicle can be suppressed. Therefore, according to this vehicle headlamp, it is possible to suppress a decrease in driver's visibility.

Alternatively, the information indicates a reception result of a millimeter wave radar of the detection device that transmits millimeter waves to the target object and receives the millimeter waves that are reflected by hitting the target object, and the calculation unit calculates the reception result. It is preferable to calculate the distance based on .

In this vehicle headlight, the distance between the vehicle and the object is calculated using millimeter wave radar. The intensity of light can be suppressed. As a result, even if a millimeter wave radar is used, glare applied to the driver of the own vehicle can be suppressed. Therefore, according to this vehicle headlamp, even if a millimeter wave radar is used, it is possible to suppress a decrease in driver's visibility.

Alternatively, it is preferable that the information indicates a photographed image taken by a stereo camera of the detection device, and that the calculation unit calculates the distance based on the photographed image.

With this vehicle headlight, the distance between the vehicle and the object is calculated using a stereo camera. strength can be suppressed. As a result, even if a stereo camera is used, glare applied to the driver of the own vehicle can be suppressed. Therefore, according to this vehicle headlamp, even if a stereo camera is used, it is possible to suppress a decrease in driver's visibility.

Further, the distance calculated by the calculation unit is D0, the elapsed time measured by the measurement unit after the distance D0 is calculated is T1, and the distance of the vehicle measured by the measurement unit in the elapsed time T1 is Assuming that the speed is V1 and the distance between the vehicle and the object at the elapsed time T1 is D1, it is preferable that the calculation unit calculates the distance D1 from the following formula.
D1=D0-V1×T1

Here, the information from the detection device indicates, for example, the proportion of the object in the image in front of the vehicle captured by the camera of the detection device and the change in the size of the object in the captured image, the reception result of the millimeter wave radar of the detection device that transmits millimeter waves to the object and receives millimeter waves reflected by the object, or the captured image captured by the stereo camera of the detection device. In this vehicle headlamp, when the calculation unit calculates the distance D0 between the vehicle and the object and then calculates the distance again after an elapsed time T1 has elapsed, the calculation unit calculates the distance based on the calculated distance D0, the vehicle speed V1, and the elapsed time T1 that has elapsed since the calculation of the distance. Therefore, when the calculation unit calculates the distance again after the elapsed time T1 has elapsed, the calculation unit does not need to use information from the detection device after the elapsed time T1 has elapsed, and only needs to use the information from the detection device once. Therefore, according to this vehicle headlamp, the burden on the calculation unit can be reduced compared to when the calculation unit uses information from the detection device every time it calculates the distance.

As described above, according to the present invention, it is possible to provide a vehicle headlamp that can suppress a decrease in driver's visibility.

FIG. 1 is a plan view conceptually showing a vehicle. FIG. 2 is a vertical cross-sectional view that shows a schematic view of one of the lamps shown in FIG. FIG. 3 is a flowchart showing the operation of the vehicle headlamp. FIG. 4 is a diagram showing changes in the amount of light depending on the distance to the object. FIG. 5 is a diagram showing a high beam light distribution pattern when the object does not meet predetermined requirements. FIG. 6 is a diagram showing a high beam light distribution pattern when the amount of light is less than the reference amount of light when the retroreflective object as the target satisfies predetermined requirements. FIG. 7 shows that when the retroreflective object that is the target object satisfies predetermined requirements, the vehicle approaches the target object from the state shown in FIG. FIG. 7 is a diagram showing a high beam light distribution pattern when the number of high beams decreases. FIG. 8 is a diagram illustrating a high beam light distribution pattern when the amount of light is less than the reference amount of light when the human object satisfies predetermined requirements. FIG. 9 is a diagram illustrating a modification of the change in the amount of light depending on the distance to the object. FIG. 10 is a plan view conceptually showing a vehicle in a modified example of distance calculation by the calculation unit.

Hereinafter, preferred embodiments of a vehicle headlamp according to the present invention will be described in detail with reference to the drawings. The embodiments illustrated below are provided to facilitate understanding of the present invention, and are not intended to be interpreted as limiting the present invention. The present invention can be modified and improved without departing from its spirit. Furthermore, the present invention may be implemented by appropriately combining the constituent elements in each of the embodiments illustrated below. Note that for ease of understanding, some parts may be exaggerated in each figure.

FIG. 1 is a plan view conceptually showing a vehicle 10. As shown in FIG. As shown in FIG. 1, the vehicle 10 includes a vehicle headlamp 20 and a detection device 100.

The vehicle headlamp 20 of this embodiment is a headlamp for an automobile. The vehicle headlamp 20 mainly comprises a pair of lamps 30 arranged on the left and right sides of the front portion of the vehicle 10, a calculation unit 37, a determination unit 40, a control unit 50, and a recording unit 60. In this specification, "right" means the right side in the traveling direction of the vehicle 10, and "left" means the left side in the traveling direction of the vehicle 10.

The pair of lamps 30 have shapes that are generally symmetrical to each other in the left-right direction of the vehicle 10. The pair of lamps 30 of this embodiment emits a low beam or a high beam to the front of the vehicle 10. The configuration of one lamp 30a of the pair of lamps 30 is the same as the configuration of the other lamp 30b of the pair of lamps 30, except that the shape is generally symmetrical.

FIG. 2 is a vertical cross-sectional view schematically showing one of the lamps 30a shown in FIG. As shown in FIG. 2, one lamp 30a mainly includes a light source 31, a reflector 32, a reflection device 33, a projection lens 34, and a light absorption plate 35.

In this embodiment, the light source 31 emits light toward the front of the light source 31 . The light source 31 is a light emitting element that emits light. An example of such a light source 31 is an LED (Light Emitting Diode) that emits white light.

In this embodiment, the reflector 32 is a curved plate-like member. The reflector 32 has a reflective surface 32r located on the inner surface of the reflector 32 having a curved surface. The reflective surface 32r is curved to have a concave shape on the side opposite to the light source 31 side. Such a reflecting surface 32r has, for example, a spheroidal curved surface shape. Further, the reflector 32 is arranged so that the reflective surface 32r covers the light source 31 from the front side. The reflecting surface 32r reflects the light emitted from the light source 31 onto a reflection control surface 33r of the reflecting device 33, which will be described later.

In this embodiment, the reflecting device 33 is disposed above the light source 31 and behind the reflector 32. The reflecting device 33 in this embodiment is a so-called DMD (Digital Mirror Device) and has a reflection control surface 33r that reflects light. The reflection control surface 33r is disposed so as to face the forward side. This reflection control surface 33r is irradiated with light emitted from the light source 31 and reflected by the reflection surface 32r of the reflector 32. The reflection control surface 33r is composed of the reflection surfaces of a plurality of reflection elements arranged two-dimensionally. These reflection elements are supported on a substrate (not shown) so as to be individually tiltable. The plurality of reflection elements are individually switchable between a first tilt state in which the light from the reflector 32 is reflected toward the projection lens 34 and a second tilt state in which the light from the reflector 32 is reflected toward the light absorbing plate 35. By controlling the tilt state of the reflecting elements, such a reflecting device 33 can form a desired light distribution pattern or change the light distribution pattern with the light traveling from the reflection control surface 33r toward the projection lens 34. In addition, by controlling the tilt state of these reflecting elements over time, the light intensity distribution of the desired light distribution pattern can be made to be the desired intensity distribution.

The projection lens 34 is a lens that adjusts the divergence angle of incident light. The projection lens 34 is disposed in front of the reflection device 33, and light directed toward the projection lens 34 is incident from the reflection control surface 33r, and the divergence angle of this light is adjusted in the projection lens 34. The projection lens 34 is a lens having a convex entrance surface and a convex exit surface. The rear focal point of the projection lens 34 is located on or near the reflection control surface 33r of the reflection device 33. A predetermined light whose divergence angle has been adjusted by such a projection lens 34 is emitted from one lamp 30a, and this predetermined light is irradiated in front of the vehicle 10.

In this embodiment, the light absorption plate 35 is arranged in front of and above the reflection device 33. The light absorption plate 35 is a plate-like member having light absorption properties, and converts most of the light incident on the light absorption plate 35 into heat. When light directed from the reflection control surface 33r toward the light absorption plate 35 is incident on the light absorption plate 35, most of this light is converted into heat by the light absorption plate 35. Heat is released from the light absorption plate 35 to the outside of the light absorption plate 35. Examples of the light absorption plate 35 include a plate-like member made of metal such as aluminum and having a surface treated with black alumite or the like.

Note that the configuration of one lamp 30a is not particularly limited to the above. One of the lamps 30a may have a configuration in which the light emitted from the light source 31 is scanned using, for example, MEMS (Micro Electro Mechanical Systems), a galvano mirror, or the like, and the light is emitted forward. Alternatively, the configuration of one of the lamps 30a is such that the light emitted from the light source 31 is diffracted using LCOS (Liquid Crystal On Silicon), a diffraction grating, etc. to form a desired light distribution pattern and emitted forward. You can.

Now, returning to FIG. 1, the description of the vehicle 10 will be continued.

In this embodiment, the detection device 100 detects an object located in front of the vehicle 10. Examples of objects detected by the detection device 100 include retroreflective objects and objects other than retroreflective objects. A retroreflective object is an object that does not emit light itself, but retroreflects light that irradiates the retroreflective object at a predetermined spread angle. Examples of such retroreflective objects include road signs installed along the road. Examples of objects other than retroreflective objects include vehicles such as a preceding vehicle or an oncoming vehicle, and humans such as pedestrians. As a configuration of the detection device 100, the detection device 100 mainly includes, for example, a camera, an image processing unit, and a detection unit (not shown). The camera is attached to the front of the vehicle 10 and captures an image in front of the vehicle 10. The captured image captured by the camera includes at least a portion of the area irradiated with light emitted from the pair of lamps 30. The image processing unit performs image processing on the captured image captured by the camera. The detection unit detects the proportion of the object in the captured image and the amount of change over time in the size of the object in the captured image from the captured image processed by the image processing unit. When a vehicle that is far from the object approaches the object over time, the amount of change in the size of the object is small, and when a vehicle that is close to the object moves forward over time and approaches the object further, the amount of change in the size of the object becomes larger. The size of the object indicates, for example, the area of the object or the width of the object. When the detection device 100 detects an object located in front of the vehicle 10, it outputs information such as the proportion of the object in the captured image and the amount of change over time in the size of the object in the captured image to the calculation unit 37. In addition, the detection device 100 outputs the captured image to the recording unit 60. Note that the objects detected by the detection device 100, the number of types of objects, and the configuration of the detection device 100 are not particularly limited. For example, the configuration of the image processing unit and the configuration of the detection unit can be the same as that of the control unit 50. The configuration of the control unit 50 will be described later.

The calculation unit 37 calculates the distance between the vehicle 10 and the object based on information from the detection device 100 that detects the object located in front of the vehicle 10. In this embodiment, the calculation unit 37 calculates the distance based on the ratio and the amount of change in the information from the detection device 100. The calculated distance is input to the determination unit 40 as information. The configuration of the calculation unit 37 may be, for example, the same configuration as the control unit 50.

The determination unit 40 determines whether the target object satisfies predetermined requirements based on the distance calculated by the calculation unit 37. The predetermined requirement includes, for example, that the distance between the vehicle 10 and the object is less than a predetermined distance. The predetermined distance is, for example, 130 m. The numerical value of this distance is recorded in the recording unit 60 as a threshold value, and may be changed as appropriate depending on the driving situation of the vehicle 10 such as daytime or nighttime. The determining unit 40 reads a predetermined distance, which is a threshold value, from the recording unit 60, compares the calculated distance with the predetermined distance, and determines whether the calculated distance is greater than the predetermined distance. If the calculated distance is greater than or equal to the predetermined distance, the determination unit 40 determines that the object does not satisfy the predetermined requirements. Furthermore, when the calculated distance is less than the predetermined distance, the determination unit 40 determines that the object satisfies the predetermined requirements. The determination result of the determination unit 40 is input to the control unit 50. Note that the predetermined requirement is not particularly limited, and may be the size of the object in the captured image instead of the distance. The configuration of the determination unit 40 may be, for example, the same configuration as the control unit 50.

For example, the control unit 50 can use an integrated circuit such as a microcontroller, an IC (Integrated Circuit), an LSI (Large-scale Integrated Circuit), or an ASIC (Application Specific Integrated Circuit), or an NC (Numerical Control) device. Furthermore, when an NC device is used, the control unit 50 may use a machine learning device or may not use a machine learning device.

The control unit 50 determines whether a control signal from a light switch (not shown) mounted on the vehicle 10 is input. The control signal is a signal instructing the start of light emission from each light source 31 of the pair of lamps 30. When the control signal is input to the control section 50, the control section 50 drives the pair of lamps 30. If the control signal is not input to the control unit 50, the control unit 50 stops driving the pair of lamps 30.

The recording unit 60 records the captured image output from the detection device 100, a predetermined distance that is the above-mentioned threshold value in the determination unit 40, and a predetermined amount of light amount, which will be described later. Examples of the recording unit 60 include a semiconductor memory such as a ROM, a magnetic disk, and the like.

Next, the operation of the vehicle headlamp 20 of this embodiment will be explained.

FIG. 3 is a flowchart showing the operation of the vehicle headlamp 20 in this embodiment. As shown in FIG. 3, the flowchart of this embodiment includes steps S1 to S6.

(Step S1)
Detection device 100 photographs the front of vehicle 10 using a camera. When detecting an object located in front of the vehicle 10 from the photographed image, the detection device 100 calculates information such as the proportion of the object in the photographed image and the amount of change over time in the size of the object in the photographed image. output to section 37. When the information is input to the calculation unit 37, the process moves to step S2.

(Step S2)
In this step, the control unit 50 determines whether or not to emit light based on the control signal from the light switch. If the control signal is not input to the control unit 50 and no light is emitted, the control unit 50 stops driving the pair of lamps 30, and the process returns to step S1. Further, when the control signal is input to the control unit 50 and light is emitted, the process moves to step S3.

(Step S3)
In this step, the calculation unit 37 calculates the distance between the vehicle 10 and the object based on the ratio and the amount of change in the information from the detection device 100 that detects the object located in front of the vehicle 10. do. The calculated distance is input to the determination section 40. The process moves to step S4.

(Step S4)
In this step, the determination unit 40 determines whether the object satisfies predetermined requirements based on the distance calculated by the calculation unit 37. Here, as described above, the predetermined requirement includes that the distance between the vehicle 10 and the object located in front of the vehicle 10 is less than the predetermined distance. If the determination unit 40 determines that the object does not satisfy the predetermined requirements, the process moves to step S5. Further, if the determination unit 40 determines that the object satisfies the predetermined requirements, the process moves to step S6.

(Step S5)
In this step, the description will be made assuming that the object is located diagonally forward to the left of the vehicle 10 and that the distance between the vehicle 10 and the object is equal to or greater than a predetermined distance. In addition, in the case where the distance between the vehicle 10 and the object is equal to or greater than a predetermined distance, the light emitted from the pair of lamps 30 toward the front of the vehicle 10 including the object is defined as reference light, and the light amount of the reference light is defined as the reference light amount. For example, the reference light amount is an amount of light that does not cause glare to the driver of the vehicle due to the light reflected from the object, even if a part of the reference light illuminating the object is reflected from the object toward the vehicle.

By the way, FIG. 4 shows changes in the amount of light depending on the distance to the object. The vertical axis in FIG. 4 indicates the amount of light, with the upper side of the vertical axis indicating a higher amount of light, and the lower side of the vertical axis indicating a lower amount of light. Further, the horizontal axis in FIG. 4 indicates the distance from the vehicle 10 to an object located in front of the vehicle 10. On the left side of the horizontal axis, the distance is long and the object is far from the vehicle 10, and on the right side of the horizontal axis, the distance is small. The short term indicates that the object is close to the vehicle 10.

In this step, as shown in FIG. 4, when the distance between the vehicle 10 and the target object is a predetermined distance or more, the control unit 50 drives the pair of lamps 30 so that the reference light amount is constant. . Thereby, the pair of lamps 30 emit the reference light toward the front of the vehicle 10. Note that in this step, control of the reference light amount is not particularly limited, and the reference light amount may be changed.

FIG. 5 is a diagram showing a high beam light distribution pattern 200 when the distance between the vehicle 10 and the object is a predetermined distance or more. Here, for example, when the target object is a retroreflective object 401 such as a road sign installed beside the road, the retroreflective object 401 is supported by a support section 403 that is a metal support erected from the side of the road. Supported. In FIG. 5, S indicates a horizontal line, and a light distribution pattern 200 is indicated by a thick line, and this light distribution pattern 200 is a light distribution pattern formed on a vertical plane 25 meters away from the vehicle 10, for example. After the reference light is emitted and the light distribution pattern 200 is formed, the process returns to step S1.

(Step S6)
This step will be described assuming that the object is located diagonally in front of the left of the vehicle 10 and that the distance between the vehicle 10 and the object is less than a predetermined distance.

In this step, the control unit 50 controls the pair of lamps 30 so that the amount of light emitted from the pair of lamps 30 toward the front of the vehicle 10 including the object decreases as the distance calculated by the calculation unit 37 becomes shorter. 30 is driven. Furthermore, in this step, the control unit 50 drives the pair of lamps 30 so that the amount of light is less than the reference amount of light. As a result, the pair of lamps 30 emit light toward the front of the vehicle 10 with a smaller amount of light as the distance becomes shorter and less than the reference amount of light. As shown in FIG. 4, the amount of light decreases after the distance between the vehicle 10 and the object becomes less than a predetermined distance.

Further, in this step, the control unit 50 controls the pair of lamps 30 so that the light amount gradually decreases from the reference light amount to a predetermined amount smaller than the reference light amount during a predetermined period. In this embodiment, the light amount decreases from the reference light amount to a predetermined amount at a constant rate of change, and decreases linearly. The predetermined period of time is, for example, the distance by which the vehicle 10 moves forward by a predetermined distance and approaches the object after the distance between the vehicle 10 and the object becomes less than a predetermined distance. Such a distance is, for example, a distance that the vehicle 10 moves forward such that the distance between the vehicle 10 and the target object is 1 m. The numerical value of this distance is recorded in the recording unit 60 as a threshold value, and may be changed as appropriate depending on the driving situation of the vehicle 10 such as daytime or nighttime. At the end point of the predetermined period, the vehicle 10 is located in front of the object. Note that at the end point of the predetermined period, the vehicle 10 may be located at a position where it passes the object, and therefore the distance between the vehicle 10 and the object may be zero. Note that the predetermined period does not need to be particularly limited, and may be, for example, the time from when the distance between the vehicle 10 and the target object becomes less than a predetermined distance until a predetermined time elapses.

Each of Fig. 6 and Fig. 7 is a diagram showing a high beam light distribution pattern when the distance between the vehicle 10 and the target is less than a predetermined distance. Fig. 6 is a diagram showing a light distribution pattern 310 when the light amount is reduced from the reference light amount, and Fig. 7 is a diagram showing a light distribution pattern 320 when the vehicle approaches the target from the state shown in Fig. 6 and the light amount is further reduced from the light amount in the light distribution pattern 310 shown in Fig. 6. The area in each of the light distribution patterns 310 and 320 where the target retroreflective object 401 and the support part 403 overlap is defined as area AR1, and the area in each of the light distribution patterns 310 and 320 excluding area AR1 is defined as area AR11.

In the light distribution pattern 310 shown in FIG. 6, light is emitted to the areas AR1 and AR11, so the amount of light in area AR1 is the same as the amount of light in area AR11. Also, the amount of light in areas AR1 and AR11 of the light distribution pattern 310 is less than the reference amount of light in the light distribution pattern 200, as described above. Therefore, even if part of the light from the pair of lamps 30 illuminates an object and part of the light is reflected from the object toward the vehicle, the intensity of the reflected light in the light distribution pattern 310 is suppressed more than the intensity of the reflected light in the light distribution pattern 200.

In the light distribution pattern 320 shown in FIG. 7, since light is emitted to the area AR1 and the area AR11, the amount of light in the area AR1 is the same as the amount of light in the area AR11. Further, since the amount of light in the area AR1 and the area AR11 of the light distribution pattern 320 is smaller than the amount of light in the area AR1 and the area AR11 of the light distribution pattern 310, the area AR1 and the area AR11 of the light distribution pattern 320 are the area of the light distribution pattern 310. It becomes darker than AR1 and area AR11. Further, the intensity of the reflected light at the light distribution pattern 320 is suppressed more than the intensity of the reflected light at the light distribution pattern 310. In this embodiment, the amount of light decreases as the distance between the vehicle 10 and the target object becomes shorter, so part of the light irradiates the target object, and part of the light is reflected from the target object to the own vehicle. Even if the reflected light is directed towards the target, the intensity of the reflected light may be suppressed. Therefore, even if the distance between the vehicle 10 and the object becomes short, glare on the driver of the own vehicle can be suppressed.

In FIG. 4, the predetermined amount of light is not turned off, but is emitted at the minimum necessary amount of light. The minimum necessary amount of light is, for example, a level of brightness that ensures the visibility of the driver of the vehicle 10 in front of the vehicle 10. When the light amount changes to a predetermined amount, the control unit 50 drives the pair of lamps 30 so that the light amount returns to the reference light amount. Here, the light amount gradually increases from the predetermined amount to the reference light amount over a certain period of time. Further, here, for example, the amount of light increases at a constant rate of change, and increases linearly. Note that the increase in light amount is not particularly limited. For example, the light amount may be increased stepwise from a predetermined amount to a reference light amount over a certain period of time. Alternatively, as the vehicle 10 approaches the object, the rate of change in the amount of light gradually increases, and the amount of light may increase in a curve like a downwardly convex arc in FIG. 4 from a predetermined amount to a reference amount of light. Alternatively, as the vehicle 10 approaches the object, the rate of change in the amount of light gradually decreases, and the amount of light may increase in a curve like an upwardly convex arc in FIG. 4 from a predetermined amount to a reference amount of light. Alternatively, the light amount may instantly return from the predetermined amount to the reference light amount. The fixed period is shorter than the predetermined period when the amount of light decreases, but may be the same as the predetermined period when the amount of light decreases. In a state where the light amount returns to the reference light amount, the vehicle 10 is located in front of the object. Note that in a state where the light amount returns to the reference light amount, the vehicle 10 may be located at a position where it passes the object, and therefore the distance between the vehicle 10 and the object may be zero.

By the way, in step S4 and step S5, even if the target object is a human such as a pedestrian, the control unit 50 drives the pair of lamps 30 and adjusts the arrangement. Light patterns 200, 310, 320 are formed. FIG. 8 is a diagram illustrating a high beam light distribution pattern 310 when the amount of light is less than the reference amount of light when the human object 405 satisfies predetermined requirements. The region of the light distribution pattern 310 where the human being 405 as the object overlaps is defined as a region AR1, and the region of the light distribution pattern 310 excluding the region AR1 is defined as a region AR11. Even when the target object is a human being 405, the light amount in the area AR1 is the same as the light amount in the area AR11 in the light distribution pattern 310, as in the case where the target object is the retroreflective object 401 shown in FIG. As described above, the light amount in the area AR1 and the area AR11 of the light distribution pattern 310 is smaller than the reference light amount in the light distribution pattern 200. Furthermore, as the vehicle 10 approaches the person 405 from the state shown in FIG. 8, the amount of light in the light distribution pattern 320 changes as shown in FIG. The amount of light in the light pattern 310 is further reduced. In this case, as in the case where the target object is the retroreflective object 401 shown in FIG. AR11 is darker than area AR1 and area AR11 of light distribution pattern 310.

Once the light intensity has been controlled as described above, processing returns to step S1.

As described above, the vehicle headlamp 20 of the present embodiment includes a pair of lamps 30 arranged in the front part of the vehicle 10 and information from the detection device 100 that detects an object located in front of the vehicle 10. Based on the calculation unit 37 that calculates the distance between the vehicle 10 and the target object, and based on the distance calculated by the calculation unit 37, it is determined whether the target object satisfies predetermined requirements. It includes a determination section 40 and a control section 50 that controls the pair of lamps 30. The control unit 50 determines that when the determination unit 40 determines that the target object satisfies predetermined requirements, the calculation unit 37 calculates the amount of light emitted from the pair of lamps 30 toward the target object. The pair of lamps 30 are controlled so that the number decreases as the distance decreases.

When light from the vehicle headlight 20 of the vehicle illuminates an object such as a road sign located in front of the vehicle, some of the light may be reflected from the object toward the vehicle. There is a concern that the reflected light toward the vehicle may cause glare to the driver of the vehicle as the distance between the vehicle 10 and the object is shorter. Here, if the specified requirement indicates that the distance between the vehicle 10 and the object is less than a specified distance, the vehicle headlight 20 of this embodiment reduces the amount of light when the distance between the vehicle 10 and the object is less than the specified distance as the distance between the vehicle 10 and the object becomes shorter. In this way, when the amount of light decreases as the distance between the vehicle 10 and the object becomes shorter, the intensity of the reflected light toward the vehicle can be suppressed more than when the amount of light does not decrease as the distance between the vehicle 10 and the object becomes shorter. As a result, even if the reflected light travels toward the vehicle, the glare to the driver of the vehicle can be suppressed. Therefore, this vehicle headlight can suppress a decrease in the driver's visibility.

Furthermore, in the vehicle headlamp 20 of the present embodiment, the control unit 50 controls the direction from the pair of lamps 30 toward the target object when the determination unit 40 determines that the target object satisfies predetermined requirements. The amount of light emitted from the pair of lamps 30 is less than the reference amount of reference light emitted toward the object when the determination unit 40 determines that the object does not meet the predetermined requirements. The pair of lamps 30 are controlled so that

Here, suppose that the predetermined requirement indicates that the distance between the vehicle 10 and the object is less than a predetermined distance, and the determination unit 40 determines that the object satisfies the predetermined requirement. , a comparison with the case where the determination unit 40 determines that the object does not meet the predetermined requirements will be described. When the amount of light in a state where the object meets the predetermined requirements is less than the reference amount of light in a state where the object does not meet the predetermined requirements, the amount of light reflected toward the vehicle will be lower than when the amount of light does not become less than the reference amount. The intensity of light can be suppressed. As a result, even if the reflected light travels toward the own vehicle, glare from being applied to the driver of the own vehicle can be suppressed. Therefore, according to this vehicle headlamp, it is possible to suppress a decrease in driver's visibility.

Furthermore, in the vehicle headlamp 20 of this embodiment, the control unit 50 controls the pair of lamps 30 so that the light amount gradually decreases from the reference light amount to a predetermined amount.

In this vehicle headlamp 20, a sharp change in the light amount from the reference light amount to the predetermined amount is suppressed. Therefore, according to this vehicle headlamp 20, it is possible to suppress a decrease in the visibility of the driver of the own vehicle due to a sudden change. Moreover, according to this vehicle headlamp 20, the driver's eyes can easily adjust to the brightness in front of the vehicle 10, compared to a case where the amount of light does not gradually decrease. Therefore, according to this vehicle headlamp 20, it is possible to suppress a decrease in visibility for the driver of the own vehicle. In this vehicle headlamp 20, the rate of change in the amount of light that decreases is constant, but the control unit 50 controls the pair of lamps 30 so that the rate of change changes midway through a predetermined period. Good too. Further, in this vehicle headlamp 20, the light amount is not limited to decreasing linearly. The control unit 50 may control the pair of lamps 30 so that the light amount decreases in a curved manner from the reference light amount to a predetermined amount. For example, as the vehicle 10 approaches the object, the rate of change in the amount of light gradually increases, and the amount of light may decrease from the reference amount of light to a predetermined amount in a curve like an upwardly convex arc in FIG. 4 . Alternatively, as the vehicle 10 approaches the object, the rate of change in the amount of light gradually decreases, and the amount of light may decrease from the reference amount of light to a predetermined amount in a curve like a downwardly convex arc in FIG. 4 .

In the vehicle headlamp 20 of the present embodiment, the information includes the proportion of the object in the photographed image in front of the vehicle taken by the camera of the detection device 100, and the temporal size of the object in the photographed image. shows the amount of change. The calculation unit 37 calculates the distance between the vehicle 10 and the object based on the ratio and the amount of change.

In this vehicle headlamp 20, the shorter the distance between the vehicle 10 and the object, the closer the vehicle 10 is to the object, and the smaller the distance between the vehicle 10 and the object, the closer the vehicle 10 is to the object. The amount of change over time becomes large. The larger the ratio and the amount of change, the smaller the amount of light, and the more the intensity of the reflected light toward the own vehicle can be suppressed. As a result, even if the reflected light travels toward the own vehicle, glare from being applied to the driver of the own vehicle can be suppressed. Therefore, according to this vehicle headlamp 20, it is possible to suppress a decrease in driver's visibility.

In this embodiment, in step S6, in a state where the distance between the vehicle 10 and the target object is less than a predetermined distance, the light amount gradually decreases from the reference light amount to a predetermined amount during a predetermined period. There is. However, as long as the light amount decreases as the distance to the object becomes shorter, the change in the light amount does not need to be limited to the above. A modified example of the change in the amount of light depending on the distance to the object will be described below.

FIG. 9 is a diagram illustrating a modification of the reduction in the amount of light depending on the distance to the object. In this modification, the control unit 50 controls the pair of lamps 30 so that the light amount decreases stepwise from the reference light amount to a predetermined amount.

In the vehicle headlamp 20 of this modification, the control unit 50 may control the lamp 30 at the timing when the amount of light gradually decreases. Therefore, the burden on the control unit 50 can be reduced compared to the case where the amount of light does not decrease stepwise.

The control unit 50 does not need to control the change in the amount of light by any one of the above embodiments and modifications, but may control the change in the amount of light by a combination of the above embodiments and modifications.

In this embodiment, the calculation unit 37 calculates the distance between the vehicle 10 and the object based on the proportion of the object in the captured image contained in the information from the detection device 100 and the amount of change in the size of the object in the captured image. However, the calculation of the distance does not need to be limited to the above. A modified example of the calculation of the distance is described below.

In the first modification, the detection device 100 includes a millimeter wave radar. Millimeter wave radar transmits millimeter waves to a target object and receives reflected waves that are reflected by hitting the target object. Therefore, in this modification, the information from the detection device 100 indicates the reception result of a millimeter wave radar that transmits millimeter waves to a target object and receives millimeter waves that are reflected by hitting the target object. The calculation unit 37 calculates the distance between the vehicle 10 and the object based on the reception result input from the millimeter wave radar.

In the vehicle headlamp 20 of this modification, the distance between the vehicle 10 and the object is calculated even by using the millimeter wave radar, and the shorter the distance between the vehicle 10 and the object, the lower the amount of light. , the intensity of reflected light toward the own vehicle can be suppressed. As a result, even if a millimeter wave radar is used, glare applied to the driver of the own vehicle can be suppressed. Therefore, according to this vehicle headlamp, even if a millimeter wave radar is used, it is possible to suppress a decrease in driver's visibility.

In the second modification, the detection device 100 includes a stereo camera that photographs the front of the vehicle 10. The stereo camera includes two cameras, and outputs images taken by each camera to the calculation unit 37. The calculation unit 37 calculates the distance based on stereo matching, which calculates the parallax between corresponding pixels that correspond to each other in the two photographed images. Therefore, in this modification, the information from the detection device 100 indicates a photographed image taken by a stereo camera, and the calculation unit 37 calculates the distance between the vehicle 10 and the object based on the photographed image from the stereo camera. Then you can understand.

In the vehicle headlamp 20 of this modified example, the distance between the vehicle 10 and the object is calculated even when a stereo camera is used, and the shorter the distance between the vehicle 10 and the object, the less light there is, and the intensity of the reflected light toward the vehicle can be suppressed. This makes it possible to suppress glare for the driver of the vehicle even when a stereo camera is used. Therefore, with this vehicle headlamp, it is possible to suppress a decrease in the driver's visibility even when a stereo camera is used.

Next, a third modification will be explained. FIG. 10 is a plan view conceptually showing a vehicle in a third modification. First, the calculation unit 37 calculates the difference between the vehicle 10 and the object based on the proportion of the object in the photographed image and the amount of temporal change in the size of the object in the photographed image, which are included in the information from the detection device 100. Calculate the distance D0. The recording unit 60 records the distance D0 as an initial value. Furthermore, in this modification, the vehicle headlamp 20 further includes a measurement unit 45 that measures the elapsed time T1 since the distance D0 was calculated and the speed V1 of the vehicle 10 during the elapsed time T1. The elapsed time T1 is, for example, the time when a certain period of time has elapsed since the distance D0 was calculated. The calculation unit 37 reads the distance D0 from the recording unit 60, and receives the speed V1 and elapsed time T1 from the measurement unit 45. The calculation unit 37 calculates the distance D1 between the vehicle 10 and the object at the elapsed time T1 using the following equation (1) based on the distance D0, the speed V1, and the elapsed time T1.
D1=D0-V1×T1...(1)

In the vehicle headlamp 20 of this modification, when the calculation unit 37 calculates the distance D1 again after the elapsed time T1 after calculating the distance D0 between the vehicle 10 and the target object, the calculation unit 37 calculates the distance D1 again. A distance D1 is calculated based on the calculated distance D0, the speed V1 of the vehicle 10, and the elapsed time T1. Therefore, when the calculation unit 37 calculates the distance D1 again after the elapse of the predetermined time period, the calculation unit 37 does not need to use the information from the detection device 100 after the elapsed time T1 has elapsed, but uses the information from the detection device 100 once. Only . Therefore, according to this vehicle headlamp 20, the burden on the calculation section 37 can be reduced compared to the case where the calculation section 37 uses information from the detection device 100 every time the calculation section 37 calculates the distance.

Note that when the distance D1 is calculated, the calculation unit 37 sets the calculated distance D1 as the distance D0, and the recording unit 60 records the set distance D0 again. The measurement unit 45 also resets the elapsed time T1, measures the elapsed time T1 since the distance D0 was set again, and measures the speed V1 again. The calculation unit 37 calculates the distance D1 again using the above equation (1). In this way, in this modification, the above processing in the calculation unit 37, the recording unit 60, and the measurement unit 45 may be repeated.

In the vehicle headlamp 20 of this modification, the calculation unit 37 uses the proportion of the object in the photographed image and the amount of change over time in the size of the object in the photographed image in order to calculate the distance D0. However, the distance D0 may be calculated using either the millimeter wave radar of the first modification or the stereo camera of the second modification. Furthermore, the distance calculations in the embodiment and the first, second, and third modifications described above may be used to calculate the distance in a predetermined period.

Although the present invention has been described above using the above embodiment and each modified example as an example, the present invention is not limited to these.

Although the configuration of one lamp 30a is the same as the configuration of the other lamp 30b, it may be different from the configuration of the other lamp 30b. The configurations of the one lamp 30a and the other lamp 30b are not particularly limited. Further, for example, one of the lamps 30a and the other lamp 30b may be a parabolic lamp 30, a projector type lamp 30, a direct lens type lamp 30, or the like.

The photographed image may be at least one of a moving image and a still image.

Regarding control of the reference light amount in a state where the distance between the vehicle 10 and the target object is a predetermined distance or more and the light amount in a state where the distance between the vehicle 10 and the target object is less than the predetermined distance, the high beam light distribution Although the description has been made using patterns, the reference light amount and the light amount are controlled in the same manner as in the high beam light distribution pattern in the low beam light distribution pattern as well.

At least a part of the configuration of the detection device 100 may be included in the configuration of the vehicle headlamp 20. In this case, the camera, stereo camera, and millimeter wave radar of the detection device 100 may be arranged inside the casing of the lamp 30. Further, the control unit 50 may function as an image processing unit and a detection unit, or the control unit 50, the image processing unit, and the detection unit may be mounted on the same control board. The image processing section may be a microcontroller or the like specialized for image processing, compared to the control section 50.

The detection unit of the detection device 100 may detect the presence of the target object and the position of the target object from information subjected to image processing by the image processing unit. Further, the detection unit of the detection device 100 may detect the presence of the object and the position of the object based on the reception result of the millimeter wave radar or the captured image of the stereo camera.

The distance calculated by the calculation unit 37 is, for example, a value expressed in SI units such as meters. Note that the calculation unit 37 does not need to calculate the actual measured value of the distance, and may calculate a value proportional to the actual measured value of the distance, and may calculate information regarding the distance such as the actual measured value of the distance or the value.

The control unit 50 determines a reference light amount in a state where the distance between the vehicle 10 and the target object is a predetermined distance or more, and a light amount in a state where the distance between the vehicle 10 and the target object is less than a predetermined distance. Although a pair of lamps 30 are controlled for control purposes, one lamp among the pair of lamps 30 may be controlled.

Light emitted toward the front of the vehicle 10 in a state where the distance between the vehicle 10 and the target object is a predetermined distance or more and a state where the distance between the vehicle 10 and the target object is less than the predetermined distance. may be light directed toward at least a portion of an object in front of the vehicle 10. In such a case, when detecting an object located in front of the vehicle 10, the detection device 100 outputs information such as the presence of the object and the location of the object to the control unit 50. Based on this information, the control unit 50 detects the area AR where the objects overlap in the light distribution patterns 310 and 320. Further, the control unit 50 controls at least one light source 31 of the pair of lamps 30 that emits light toward at least a part of the area AR. Here, the control unit 50 may control the light source 31 so that the amount of light emitted from the light source 31 is smaller than the reference light amount as described above. Note that the light emitted toward the front of the vehicle 10 may be light toward at least an object in front of the vehicle 10. Even in such a case, the control unit 50 may control the light source 31 so that the amount of light emitted from the light source 31 toward the object is smaller than the reference amount of light.

The amount of light that has changed to the predetermined amount does not need to return to the reference amount of light, but only needs to be greater than the predetermined amount. Therefore, the light amount that has changed to the predetermined amount may change to a light amount between the predetermined amount and the reference light amount, or may be greater than the reference light amount.

The amount of light directed toward the front of the vehicle 10 excluding the object from the pair of lamps 30 may remain the reference amount of light.

As explained above, according to the present invention, there is provided a vehicle headlamp that can suppress a decrease in driver's visibility, and the vehicle headlamp is used in the field of vehicle headlights such as automobiles. Available at

DESCRIPTION OF SYMBOLS 10... Vehicle 20... Vehicle headlamp 30... Light fixture 37... Calculation part 40... Judgment part 50... Control part 60... Recording part 100... Detection device

Claims (8)

A light fixture placed in the front part of the vehicle;
a calculation unit that calculates a distance between the vehicle and the object based on information from a detection device that detects an object located in front of the vehicle;
a determination unit that determines whether the target object satisfies predetermined requirements based on the distance calculated by the calculation unit;
a control unit that controls the lamp;
Equipped with
The control unit is configured such that when the determination unit determines that the object satisfies the predetermined requirements, the amount of light emitted from the lamp toward at least a portion of the object is such that the amount of light emitted from the lamp toward at least a portion of the object is In a range where the distance calculated by the calculation unit is less than a predetermined distance and is shorter than the predetermined distance, the smaller the distance becomes, the smaller the distance becomes. A vehicular headlamp characterized in that the lamp is controlled such that the shorter the distance, the greater the amount of light at the specific distance . The control unit controls the lamp so that, when the determination unit determines that the object is in a state satisfying the specified requirements, the amount of light emitted from the lamp toward at least a portion of the object is less than a reference light amount indicating the amount of reference light that is emitted from the lamp toward at least a portion of the object when the determination unit determines that the object is not in a state satisfying the specified requirements. 1 . The control unit controls the lamp so that, in a range where the distance is less than the predetermined distance and greater than or equal to the specific distance, the amount of light gradually decreases as the distance becomes shorter. Or a vehicle headlamp according to claim 2. The control unit controls the lamp so that in a range where the distance is less than the predetermined distance and greater than or equal to the specific distance, the amount of light decreases in stages as the distance becomes shorter. The vehicle headlamp according to claim 1 or claim 2. The information indicates a proportion of the object in a photographed image in front of the vehicle taken by the detection device and a temporal change in the size of the object detected from the photographed image,
The vehicle headlamp according to any one of claims 1 to 4, wherein the calculation unit calculates the distance based on the ratio and the amount of change. The information indicates a reception result of a millimeter wave radar of the detection device that transmits millimeter waves to the target object and receives the millimeter waves that are reflected by hitting the target object,
The vehicle headlamp according to any one of claims 1 to 4, wherein the calculation unit calculates the distance based on the reception result. The information indicates a captured image captured by a stereo camera of the detection device,
The vehicle headlamp according to any one of claims 1 to 4, wherein the calculation unit calculates the distance based on the photographed image. The distance calculated by the calculation unit is D0, the time that has elapsed since the distance D0 was calculated and is measured by the measurement unit is T1, and the distance that is measured by the measurement unit in the elapsed time T1 is Assuming that the speed of the vehicle is V1 and the distance between the vehicle and the object at the elapsed time T1 is D1, the calculation unit calculates the distance D1 from the following formula: D1=D0−V1× T1
The vehicle headlamp according to any one of claims 5 to 7, characterized in that:

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