JP5530125B2 - Vehicle headlamp device - Google Patents

Description

  The present invention relates to a vehicle headlamp device, and more particularly to a vehicle headlamp device used in an automobile or the like.

  In general, a vehicle headlamp apparatus can switch between a low beam and a high beam. The low beam illuminates the vicinity with a predetermined illuminance so as not to give glare to the preceding vehicle including the oncoming vehicle and the preceding vehicle, and is mainly used when traveling in an urban area. On the other hand, the high beam illuminates a wide area in the front and a distant area with a relatively high illuminance, and is mainly used when traveling at high speed on a road with few front vehicles.

  The high beam is more visible to the driver than the low beam, but there is a problem that glare is given to the driver of another vehicle. Therefore, a low beam is often used particularly during night driving in an urban area, and a high beam light source is not used during a low beam. On the other hand, there is always a demand for improving the visibility of the road by the driver during low beam.

  On the other hand, Patent Document 1 includes a configuration capable of forming a light distribution pattern in which only one side region in front of the vehicle is a high beam by combining two light shielding plates provided so as to be movable back and forth with respect to the light flux. A technique is disclosed in which a light distribution pattern in which one side region on a different side becomes a high beam is formed and a light shielding region is formed in accordance with the existing region of the preceding vehicle by swiveling each lamp.

German Patent Application No. 102007045150

  In the above situation, the present inventor has come to recognize the following problems. That is, in Patent Document 1 described above, when the number of front vehicles increases, the light distribution pattern frequently changes in a short time, which may give the driver a visual discomfort or discomfort. In addition, if the number of vehicles ahead is large, it is easy to overlook the presence of vehicles ahead and delay the deformation of the light distribution pattern, making it difficult to form an appropriate light distribution pattern that matches the presence of vehicles ahead. There was a risk of glare.

  The present invention has been made on the basis of such recognition by the inventor, and the purpose thereof is that the driver may feel uncomfortable or uncomfortable when the light distribution pattern is changed in accordance with the presence of the vehicle ahead. An object of the present invention is to provide a technique for reducing the possibility of giving glare to a preceding vehicle.

  In order to solve the above problems, a vehicle headlamp device according to an aspect of the present invention includes a lamp unit capable of forming an additional light distribution pattern including a region above the cut-off line of a low beam light distribution pattern, and a vehicle ahead. A control unit that controls light irradiation by the lamp unit according to the presence of the lamp, and the control unit limits the formation of the additional light distribution pattern when the number of vehicles ahead exceeds a predetermined threshold value. It is characterized by doing.

  According to this aspect, when changing the light distribution pattern according to the presence of the preceding vehicle, it is possible to reduce the possibility of giving the driver a sense of discomfort or discomfort and the possibility of giving glare to the preceding vehicle.

  In the above aspect, the control unit may determine that the number of front vehicles exceeds a threshold when the total number of front vehicles per unit time detected by the vehicle detection device exceeds a predetermined value. This also reduces the possibility of giving the driver a sense of discomfort and discomfort and the possibility of giving glare to the preceding vehicle when changing the light distribution pattern according to the presence of the preceding vehicle.

  In the above aspect, the control unit determines that the number of front vehicles exceeds a threshold when the number of times of control per unit time in the formation control of the additional light distribution pattern according to the presence of the front vehicle exceeds a predetermined value. May be. This also reduces the possibility of giving the driver a sense of discomfort and discomfort and the possibility of giving glare to the preceding vehicle when changing the light distribution pattern according to the presence of the preceding vehicle.

  In the above aspect, when the number of front vehicles exceeds the threshold value, the control unit is configured to provide additional arrangement in which at least a part of the cut-off line has a lower height than when the number of front vehicles is the threshold value or less. An optical pattern may be formed. According to this, the driver's visibility can be improved, and the possibility of giving the driver a sense of discomfort and discomfort and the possibility of giving glare to the preceding vehicle can be reduced.

  Further, in the above aspect, when the number of front vehicles exceeds a threshold value, the control unit may form an additional light distribution pattern with lower illuminance than when the number of front vehicles is equal to or less than the threshold value. . According to this, the driver's visibility can be improved, and the possibility of giving the driver a sense of discomfort and discomfort and the possibility of giving glare to the preceding vehicle can be reduced.

  In the above aspect, the control unit may prohibit the formation of the additional light distribution pattern when the number of front vehicles exceeds a threshold value. According to this, the possibility of giving the driver a sense of discomfort and discomfort and the possibility of giving glare to the preceding vehicle can be more reliably reduced.

  ADVANTAGE OF THE INVENTION According to this invention, when changing a light distribution pattern according to presence of a front vehicle, possibility of giving a driver discomfort and discomfort and possibility of giving glare to a front vehicle can be reduced.

1 is a schematic vertical cross-sectional view illustrating an internal structure of a vehicle headlamp device according to a first embodiment. It is a schematic perspective view of a rotation shade. It is a functional block diagram explaining operation | movement cooperation with the irradiation control part of a headlamp unit, and the vehicle control part by the side of a vehicle. 4A to 4F are explanatory diagrams showing the shape of the light distribution pattern. 5 is a control flowchart of automatic light distribution pattern formation control performed according to the presence state and the number of vehicles ahead in the first embodiment. FIG. 10 is a diagram for explaining the relationship between the total number of front vehicles per unit time and the formation restriction of an additional light distribution pattern in the vehicle headlamp device according to the second embodiment. 10 is a control flowchart of automatic light distribution pattern formation control performed in accordance with the presence state and the number of vehicles ahead in Embodiment 2. FIG. 10 is a diagram for explaining a relationship between the number of times of formation of an additional light distribution pattern and the formation restriction of the additional light distribution pattern in the vehicle headlamp device according to the third embodiment. 10 is a control flowchart of automatic light distribution pattern formation control performed in accordance with the presence state and the number of vehicles ahead in Embodiment 3.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. The embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

(Embodiment 1)
FIG. 1 is a schematic vertical sectional view for explaining the internal structure of the vehicle headlamp device according to the first embodiment. The vehicle headlamp device 200 of the present embodiment is a variable light distribution headlamp in which headlamp units are arranged one by one on the left and right in the vehicle width direction of the vehicle. Since the left and right headlamp units have substantially the same configuration except that they have a symmetrical structure, the structure of the right headlamp unit 210R will be described below, and the left headlamp will be described. The description of the unit is omitted as appropriate. In addition, when describing each member of the left headlamp unit, the same reference numerals as those of the corresponding member of the headlamp unit 210R are attached to each member for convenience of explanation.

  The headlamp unit 210R has a lamp chamber 216 formed by a lamp body 212 having an opening on the front side of the vehicle and a translucent cover 214 covering the opening. The lamp chamber 216 houses the lamp unit 10 that irradiates light in the forward direction of the vehicle. A lamp bracket 218 having a pivot mechanism 218 a serving as a swing center in the vertical and horizontal directions of the lamp unit 10 is formed in a part of the lamp unit 10. The lamp bracket 218 is connected to a body bracket 220 fixed to the inner wall surface of the lamp body 212 by a fastening member such as a screw. Therefore, the lamp unit 10 is fixed at a predetermined position in the lamp chamber 216 and can be changed in posture, such as a forward leaning posture or a backward leaning posture, around the pivot mechanism 218a.

  In addition, on the lower surface of the lamp unit 10, a rotating shaft of a swivel actuator 222 for configuring a curved road light distribution variable headlight (Adaptive Front-lighing System: AFS) that illuminates the traveling direction when traveling on a curved road or the like. 222a is fixed. The swivel actuator 222 is based on the steering amount data provided from the vehicle side, the shape data of the traveling road provided from the navigation system, the relationship between the relative position of the preceding vehicle and the host vehicle including the oncoming vehicle and the preceding vehicle, etc. The lamp unit 10 is swiveled (swiveled) in the traveling direction around the pivot mechanism 218a. As a result, the irradiation area of the lamp unit 10 is directed to the tip of the curve road instead of the front of the vehicle, and the forward visibility of the driver is improved. The swivel actuator 222 can be composed of a stepping motor, for example. When the swivel angle is a fixed value, a solenoid or the like can be used.

  The swivel actuator 222 is fixed to the unit bracket 224. A leveling actuator 226 disposed outside the lamp body 212 is connected to the unit bracket 224. The leveling actuator 226 is composed of, for example, a motor that expands and contracts the rod 226a in the directions of arrows M and N. When the rod 226a extends in the direction of the arrow M, the lamp unit 10 swings so as to be in a backward inclined posture with the pivot mechanism 218a as the center. On the other hand, when the rod 226a is shortened in the direction of arrow N, the lamp unit 10 swings so as to assume a forward leaning posture with the pivot mechanism 218a as the center. When the lamp unit 10 is tilted backward, leveling adjustment with the optical axis directed upward can be performed. In addition, when the lamp unit 10 is in the forward tilted posture, leveling adjustment that directs the optical axis downward can be performed. By performing such leveling adjustment, the optical axis can be adjusted according to the vehicle posture. As a result, the reach distance of the front irradiation light by the vehicle headlamp device 200 can be adjusted to an optimum distance.

  This leveling adjustment can also be executed in accordance with the vehicle posture while the vehicle is running. For example, when the vehicle is accelerated while traveling, the vehicle posture is a backward leaning posture, and conversely, when the vehicle is decelerated, it is a forward leaning posture. Therefore, the irradiation direction of the vehicular headlamp device 200 also fluctuates up and down corresponding to the posture state of the vehicle, and the front irradiation distance becomes longer or shorter. Therefore, by executing the leveling adjustment of the lamp unit 10 in real time based on the vehicle posture, it is possible to optimally adjust the front irradiation reach distance even during traveling. This is sometimes referred to as “auto-leveling”.

  On the inner wall surface of the lamp chamber 216 below the lamp unit 10, an irradiation control unit 228 (control unit) that performs lighting on / off control of the lamp unit 10 and light distribution pattern formation control is arranged. In the case of FIG. 1, an irradiation control unit 228R for controlling the headlamp unit 210R is arranged. The irradiation control unit 228R also executes control of the swivel actuator 222, the leveling actuator 226, and the like.

  The lamp unit 10 can include an aiming adjustment mechanism. For example, an aiming pivot mechanism (not shown) serving as a swing center at the time of aiming adjustment is disposed at a connecting portion between the rod 226a of the leveling actuator 226 and the unit bracket 224. In addition, a pair of aiming adjustment screws (not shown) that move forward and backward in the vehicle front-rear direction are disposed at a connection portion between the body bracket 220 and the lamp bracket 218 with a gap in the vehicle width direction. For example, if two aiming adjustment screws are advanced forward, the lamp unit 10 is inclined forward with the aiming pivot mechanism as the center, and the optical axis is adjusted downward. Similarly, when the two aiming adjusting screws are pulled back, the lamp unit 10 is tilted backward with the aiming pivot mechanism as the center, and the optical axis is adjusted upward. Further, if the aiming adjustment screw on the left side in the vehicle width direction is advanced forward, the lamp unit 10 turns right around the aiming pivot mechanism, and the optical axis is adjusted rightward. Further, when the aiming adjustment screw on the right side in the vehicle width direction is advanced forward, the lamp unit 10 assumes a left turning posture around the aiming pivot mechanism, and the optical axis is adjusted in the left direction. This aiming adjustment is performed when the vehicle is shipped or inspected, or when the vehicle headlamp device 200 is replaced. Then, the vehicle headlamp device 200 is adjusted to a prescribed posture determined by design, and the light distribution pattern formation control of the present embodiment is performed based on this posture.

  The lamp unit 10 includes a shade mechanism 18 including a rotary shade 12, a bulb 14 as a light source, a lamp housing 17 that supports a reflector 16 on an inner wall, and a projection lens 20. As the bulb 14, for example, an incandescent bulb, a halogen lamp, a discharge bulb, an LED, or the like can be used. In the present embodiment, an example in which the bulb 14 is constituted by a halogen lamp is shown. The reflector 16 reflects light emitted from the bulb 14. A part of the light from the bulb 14 and the light reflected by the reflector 16 is guided to the projection lens 20 through the rotary shade 12.

  FIG. 2 is a schematic perspective view of the rotary shade. The rotary shade 12 is a cylindrical member that can rotate around a rotary shaft 12a. Further, the rotary shade 12 has a notch 22 that is partially cut in the axial direction, and a plurality of plate-like shade plates 24 are held on the outer peripheral surface 12 b other than the notch 22. The rotary shade 12 can move either the notch 22 or the shade plate 24 to the rear focal position of the projection lens 20 on the optical axis O according to the rotation angle. Thereby, the light distribution pattern according to the ridgeline part shape of the shade plate 24 arrange | positioned on the optical axis O is formed. For example, by moving any one of the shade plates 24 of the rotary shade 12 onto the optical axis O and blocking a part of the light emitted from the bulb 14, the light distribution pattern for low beam or a part for high beam is used. A light distribution pattern including the characteristics of the light distribution pattern is formed. Further, the light distribution pattern for high beam is formed by moving the notch portion 22 on the optical axis O to make the light irradiated from the bulb 14 non-shielded.

  The rotary shade 12 can be rotated by, for example, motor driving, and moves the shade plate 24 or the notch 22 for forming a desired light distribution pattern on the optical axis O by controlling the amount of rotation of the motor. In addition, the notch 22 of the outer peripheral surface 12b of the rotary shade 12 may be omitted, and the rotary shade 12 may have only a light shielding function. When forming a high beam light distribution pattern, for example, a solenoid is driven to retract the rotary shade 12 from the position of the optical axis O. With such a configuration, for example, even if the motor that rotates the rotary shade 12 fails, the low beam light distribution pattern or a similar light distribution pattern is fixed. That is, the fail-safe function can be realized by reliably avoiding that the rotary shade 12 is fixed in the formation posture of the high beam light distribution pattern.

  Returning to FIG. 1, at least a part of the reflector 16 has an elliptical spherical shape, and this elliptical spherical surface is set so that the cross-sectional shape including the optical axis O of the lamp unit 10 is at least a part of an elliptical shape. ing. The elliptical spherical portion of the reflector 16 has a first focal point substantially at the center of the bulb 14 and a second focal point on the rear focal plane of the projection lens 20.

  The projection lens 20 is disposed on the optical axis O extending in the vehicle front-rear direction, and the bulb 14 is disposed on the rear side of the rear focal plane that is the focal plane including the rear focal point of the projection lens 20. The projection lens 20 is a plano-convex aspherical lens having a convex front surface and a flat rear surface, and a virtual vertical front of the vehicle headlamp device 200 with a light source image formed on the rear focal plane as an inverted image. Project on the screen. The configuration of the lamp unit 10 is not particularly limited to this, and may be a reflective lamp unit without the projection lens 20.

  FIG. 3 is a functional block diagram for explaining the cooperation between the irradiation control unit of the headlamp unit configured as described above and the vehicle control unit on the vehicle side. As described above, the configuration of the right headlight unit 210R and the left headlight unit 210L is basically the same, so only the headlamp unit 210R side will be described and the headlight unit 210L side will be described. Description is omitted.

  The irradiation control unit 228R of the headlamp unit 210R controls the power supply circuit 230 based on information obtained from the vehicle control unit 302 mounted on the vehicle 300, and performs lighting control of the bulb 14. The irradiation control unit 228R controls the variable shade control unit 232, the swivel control unit 234, and the leveling control unit 236 based on information obtained from the vehicle control unit 302. The variable shade control unit 232 controls the rotation of a motor 238 connected to the rotary shaft 12a of the rotary shade 12 via a gear mechanism to move the desired shade plate 24 or the notch 22 onto the optical axis O. The variable shade control unit 232 is provided with rotation information indicating the rotation state of the rotary shade 12 from a detection sensor such as an encoder provided in the motor 238 or the rotary shade 12, and accurate rotation control is realized by feedback control. The

  The swivel control unit 234 controls the swivel actuator 222 to adjust the optical axis of the lamp unit 10 in the vehicle width direction. For example, the light axis of the lamp unit 10 is directed in the direction of travel when turning such as traveling on a curved road or turning left and right. Further, the leveling control unit 236 controls the leveling actuator 226 to adjust the optical axis of the lamp unit 10 in the vehicle vertical direction. For example, the posture of the lamp unit 10 is adjusted according to the forward and backward tilt of the vehicle posture at the time of acceleration / deceleration to adjust the reach distance of the front irradiation light to the optimum distance. The vehicle control unit 302 provides similar information to the headlamp unit 210L, and the irradiation control unit 228L (control unit) provided in the headlamp unit 210L performs the same control as the irradiation control unit 228R. Run.

  In the case of this embodiment, the light distribution pattern formed by the headlamp units 210L and 210R can be switched according to the operation content of the light switch 304 by the driver. In this case, according to the operation of the light switch 304, the irradiation controllers 228L and 228R control the motor 238 via the variable shade controller 232 to determine the light distribution pattern.

  The headlamp units 210L and 210R of the present embodiment detect the vehicle surroundings with various sensors regardless of the operation of the light switch 304, and form a light distribution pattern optimal for the state of the vehicle 300 and the vehicle surroundings. It may be automatically controlled to do so. For example, when it can be detected that a preceding vehicle, an oncoming vehicle, a pedestrian, or the like is present in front of the host vehicle, the irradiation control units 228L and 228R prevent glare based on information obtained from the vehicle control unit 302. The light distribution pattern for low beam is formed. In addition, when it is detected that there is no preceding vehicle, oncoming vehicle, or pedestrian in front of the host vehicle, the irradiation control units 228L and 228R determine that the driver's visibility should be improved. A high beam light distribution pattern without light shielding by the rotary shade 12 is formed. In addition to the low beam light distribution pattern and the high beam light distribution pattern, if a special high beam light distribution pattern or a special low beam light distribution pattern, which will be described later, can be formed, the front vehicle An optimal light distribution pattern in consideration of the above may be formed. Such a control mode may be referred to as an ADB (Adaptive Driving Beam) mode.

  In order to detect an object such as a preceding vehicle or an oncoming vehicle in this way, a camera 306 such as a stereo camera is connected to the vehicle control unit 302 as object recognition means. Image frame data captured by the camera 306 is subjected to predetermined image processing such as object recognition processing by the image processing unit 308, and the recognition result is provided to the vehicle control unit 302. For example, when the recognition result data provided from the image processing unit 308 includes data including feature points indicating the vehicle that the vehicle control unit 302 holds in advance, the vehicle control unit 302 recognizes the presence of the vehicle. Then, the information is provided to the irradiation controllers 228L and 228R. The irradiation controllers 228L and 228R receive vehicle information from the vehicle controller 302 and form an optimal light distribution pattern considering the vehicle. Here, the “characteristic point indicating the vehicle” is, for example, a light spot of a predetermined luminous intensity or higher that appears in an estimated presence area of a headlamp of a preceding vehicle or a marker lamp such as a tail lamp. In addition, when the recognition result data provided from the image processing unit 308 includes data including feature points indicating pedestrians stored in advance, the vehicle control unit 302 sends the information to the irradiation control units 228L and 228R. The irradiation control units 228L and 228R provide an optimal light distribution pattern considering the pedestrian.

  The vehicle control unit 302 can also acquire information from a steering sensor 310, a vehicle speed sensor 312 and the like that are normally mounted on the vehicle 300. Thus, the irradiation control units 228L and 228R select a light distribution pattern to be formed according to the traveling state and traveling posture of the vehicle 300, or simply change the light distribution pattern by changing the direction of the optical axis. can do. For example, when the vehicle control unit 302 determines that the vehicle is turning based on information from the steering sensor 310, the irradiation control units 228L and 228R that have received information from the vehicle control unit 302 control the rotation of the rotary shade 12. Thus, the shade plate 24 that forms a light distribution pattern that improves the visibility in the turning direction can be selected. In addition, the swivel actuator 222 may be controlled by the swivel control unit 234 so that the optical axis of the lamp unit 10 is directed in the turning direction without changing the rotation state of the rotary shade 12 so as to improve the field of view. Such a control mode may be referred to as a turning sensitive mode.

  Further, when traveling at high speed at night, it is preferable to illuminate the front of the host vehicle so that an oncoming vehicle, a preceding vehicle, a road sign, or a message board approaching from a distance can be recognized as soon as possible. Therefore, when the vehicle control unit 302 determines that the vehicle is traveling at a high speed based on information from the vehicle speed sensor 312, the irradiation control units 228L and 228R control the rotation of the rotary shade 12 to control a part of the low beam light distribution pattern. You may select the shade plate 24 which forms the low-beam light distribution pattern of the highway mode which changed the shape. Similar control can be realized by controlling the leveling actuator 226 by the leveling control unit 236 to change the lamp unit 10 to the backward tilted posture. The above-described automatic leveling control during acceleration / deceleration by the leveling actuator 226 is control that maintains the irradiation distance constant. If this control is used to positively control the height of the cut-off line, a control equivalent to a control for selecting a different cut-off line by rotating the rotary shade 12 can be performed. Such a control mode may be referred to as a speed sensitive mode.

  Further, the vehicle control unit 302 can also acquire information from an unillustrated inter-vehicle distance sensor mounted on the vehicle 300, and the irradiation control units 228L and 228R correspond to the distance (inter-vehicle distance) between the preceding vehicle and the own vehicle. The height of the cut-off line of the light distribution pattern can be adjusted. For example, when the vehicle control unit 302 determines that the preceding vehicle is relatively far based on information from the inter-vehicle distance sensor, the irradiation control units 228L and 228R control the leveling actuator 226 by the leveling control unit 236 to control the lamp unit 10. Is changed to a tilted posture. As a result, the cut-off line of the light distribution pattern for the low beam is slightly raised, and the driver's visibility can be improved while preventing glare to the preceding vehicle. The light distribution pattern formed by such control may be called a dynamic cut-off line.

  The optical axis adjustment of the lamp unit 10 can be executed without using the swivel actuator 222 or the leveling actuator 226. For example, the lamp unit 10 may be swung or the forward tilted posture or the backward tilted posture may be performed by performing the aiming control in real time, thereby improving the visibility in a desired direction.

  In addition, the vehicle control unit 302 can also acquire road shape information and form information, road sign installation information, and the like from the navigation system 314. By acquiring these pieces of information in advance, the irradiation controllers 228L and 228R can control the leveling actuator 226, swivel actuator 222, motor 238 and the like to smoothly form a light distribution pattern suitable for the traveling road. . Such a control mode may be referred to as a navigation sensitive mode. The automatic light distribution pattern formation control including the various control modes described above is executed when automatic light formation control is instructed by the light switch 304, for example.

  Next, light distribution patterns that can be formed by the headlight units 210L and 210R of the vehicle headlight device 200 will be described. 4A to 4F are explanatory diagrams showing the shape of the light distribution pattern. 4A to 4F show a light distribution pattern formed on a virtual vertical screen arranged at a predetermined position in front of the lamp, for example, at a position 25 m ahead of the lamp.

  As described above, the headlamp unit 210L and the headlamp unit 210R have substantially the same structure, and therefore can form the same light distribution pattern. Further, as shown in FIG. 1, the projection lens 20 is a plano-convex aspheric lens having a convex front surface and a flat rear surface, so that each light distribution pattern is shielded by a shade plate 24 corresponding thereto. The light source image including the part is inverted vertically and horizontally. Therefore, the cut-off line shape of each light distribution pattern corresponds to the ridge line shape of each shade plate 24.

  The light distribution pattern shown in FIG. 4A is a basic low beam light distribution pattern Lo1. The basic low beam light distribution pattern Lo1 is a light distribution pattern that is designed so as not to give glare to the preceding vehicle or pedestrian when passing on the left side. The basic low beam light distribution pattern Lo1 has an opposite lane side cut-off line extending parallel to the horizontal H-H line on the right side of the V-V line at the upper end, and on the left side of the V-V line. The own lane side cut-off line that extends parallel to the HH line at a position higher than the oncoming lane side cut off line, and the diagonal cut off line that connects the opposite lane side cut off line and the own lane side cut off line, respectively. Have. The diagonal cut-off line extends from the intersection of the opposite lane side cut-off line and the VV line diagonally upward to the left with an inclination angle of 45 °.

  The light distribution pattern shown in FIG. 4B is a Dover low beam light distribution pattern Lo2 that forms a so-called “Dover low beam”. The light distribution pattern Lo2 for Dover low beam is a light distribution pattern that is considered so as not to give glare to the preceding vehicle or pedestrians when passing on the right side. The Dover low beam light distribution pattern Lo2 is substantially line symmetric with the basic low beam light distribution pattern Lo1 with the VV line as the axis of symmetry.

  The light distribution pattern shown in FIG. 4C is a high beam light distribution pattern Hi1. The high beam light distribution pattern Hi1 is a light distribution pattern that illuminates a wide area in the front and far away, and is formed, for example, when it is not necessary to consider glare to the vehicle ahead or a pedestrian. Specifically, it is formed when there is no forward vehicle or a pedestrian, or when the forward vehicle or the like is at a long distance so as not to receive glare even if the high beam light distribution pattern Hi1 is formed. The high beam light distribution pattern Hi1 corresponds to an additional light distribution pattern including a region above the cut-off line of the low beam light distribution pattern.

  The light distribution pattern shown in FIG. 4D is a left-side high light distribution pattern Hi2 that forms a so-called “left-side high beam”. The left high-side light distribution pattern Hi2 is a special high-beam light distribution pattern that shields the opposite lane side of the high-beam light distribution pattern Hi1 during left-hand traffic and irradiates only the own lane side in the high-beam region. The left-side high light distribution pattern Hi2 is preferably used when there is no preceding vehicle or pedestrian in the own lane and there is an oncoming vehicle or pedestrian in the oncoming lane, and glare is applied to the oncoming vehicle or pedestrian. Without giving, the driver's visibility can be enhanced by high beam irradiation only on the own lane side. The left-side high light distribution pattern Hi2 corresponds to an additional light distribution pattern including a region above the cut-off line of the low beam light distribution pattern.

  The light distribution pattern shown in FIG. 4E is a right-side high light distribution pattern Hi3 that forms a so-called “right-side high beam”. The right-side high light distribution pattern Hi3 is a special high-beam light distribution pattern that shields the own-lane side of the high-beam light distribution pattern Hi1 during left-hand traffic and irradiates only the opposite lane side in the high-beam region. The right-side high light distribution pattern Hi3 is preferably used when there is no oncoming vehicle or pedestrian in the oncoming lane and there is a preceding vehicle or pedestrian in the own lane, and glare is applied to the preceding vehicle or pedestrian. Visibility can be improved by high beam irradiation only on the opposite lane side without giving. The right side high light distribution pattern Hi3 corresponds to an additional light distribution pattern including a region above the cut-off line of the low beam light distribution pattern.

  The light distribution pattern shown in FIG. 4F is a V beam light distribution pattern Lo3 that forms a so-called “V beam”. The V-beam light distribution pattern Lo3 is a special low-beam light distribution pattern in which both the own lane side cut-off line and the opposite lane side cut-off line have the same height as the horizontal line, and have an intermediate characteristic between the low beam and the high beam. It is. The V-beam light distribution pattern Lo3 is a basic low-beam light distribution pattern Lo1L formed by the headlight unit 210L (for the sake of convenience, the light distribution pattern formed by the headlight unit 210L has the code of each light distribution pattern). The light distribution pattern formed with the headlamp unit 210R is denoted by “L” later, and the symbol “R” is appended to the light distribution pattern after each light distribution pattern. The same applies to the headlamp unit 210R. Can be formed by superimposing the light distribution pattern Lo2R for Dover low beam formed in (1). As described above, the basic low beam light distribution pattern Lo1L has an oblique cut-off line, and the Dover low beam light distribution pattern Lo2R is line-symmetric with the basic low beam light distribution pattern Lo1L. Therefore, the V-beam light distribution pattern Lo3 has a substantially V-shaped light shielding region formed by two oblique cut-off lines below the central horizontal line. Further, since the basic low beam light distribution pattern Lo1L and the Dover low beam light distribution pattern Lo2R are superimposed, the light irradiation area on the opposite lane side of the V beam light distribution pattern Lo3 is the opposite lane of the basic low beam light distribution pattern Lo1. It moves upward from the light irradiation area on the side. On the other hand, the light irradiation area on the own lane side moves upward with respect to the Dover low beam light distribution pattern Lo2. Therefore, the V-beam light distribution pattern Lo3 is a light distribution pattern that can improve the driver's visibility compared to the basic low-beam light distribution pattern Lo1 and the Dover low-beam light distribution pattern Lo2. The V-beam light distribution pattern Lo3 can increase the driver's visibility by irradiating light up to the same height as the horizontal line without giving glare to the front vehicle or the walking vehicle that is relatively far away. The V-beam light distribution pattern Lo3 corresponds to an additional light distribution pattern including a region above the cut-off line of the low-beam light distribution pattern.

  The vehicle headlamp device 200 having the above-described configuration can further form a so-called split light distribution pattern. This split light distribution pattern is a special high beam light distribution pattern having a light shielding region at the center above the horizontal line and having high beam regions on both sides of the light shielding region in the horizontal direction. The split light distribution pattern corresponds to an additional light distribution pattern including a region above the cut-off line of the low beam light distribution pattern. The split light distribution pattern can be formed by superimposing the left high light distribution pattern Hi2L formed by the headlamp unit 210L and the right high light distribution pattern Hi3R formed by the headlamp unit 210R. it can. When the split light distribution pattern is formed, both light distribution patterns are overlapped so that the high beam region of the left high-beam light distribution pattern Hi2L and the high beam region of the right high-beam light distribution pattern Hi3R are not in contact with each other. Is formed. The light shielding area is formed by swiveling the lamp unit 10 of the headlamp units 210L and 210R and moving at least one of the left-side high light distribution pattern Hi2L and the right-side high light distribution pattern Hi3R in the horizontal direction. The range can be changed.

  When the vehicle control unit 302 detects the presence of a preceding vehicle based on information obtained from the camera 306 in a state where the automatic switch control of the light distribution pattern is instructed by the light switch 304, the information is received from the vehicle control unit 302. The irradiation controllers 228L and 228R determine whether or not the vehicle ahead is within the range where the light shielding area can be formed. When the preceding vehicle is within the range where the light shielding area can be formed, the irradiation controllers 228L and 228R form a split light distribution pattern that includes the preceding vehicle in the light shielding area. Further, the irradiation control units 228L and 228R deform the light shielding region in accordance with the position of the moving front vehicle in accordance with an instruction from the vehicle control unit 302. If the preceding vehicle deviates from the range in which the light shielding area can be formed, the irradiation control units 228L and 228R determine the left-side high light distribution pattern Hi2L and the right-side high light distribution pattern Hi3R so that the preceding vehicle is not included in the irradiation area. At least one of the illuminances is reduced. With the above control, it is possible to improve the visibility of the driver in other areas, particularly the left and right road shoulder areas, while preventing glare from being given to the preceding vehicle. The “reduction” includes a case where the illuminance of the light distribution pattern is reduced to a level that does not give glare to the preceding vehicle while the light distribution pattern is formed, and a case where the illuminance of the light distribution pattern is set to zero. When the illuminance of the light distribution pattern is set to 0, the irradiation control units 228L and 228R include switching to the basic low beam light distribution pattern Lo1.

  Next, an example of light distribution pattern formation control by the vehicle headlamp device 200 according to the present embodiment having the above-described configuration will be described. In the present embodiment, the irradiation control units 228L and 228R form a predetermined additional light distribution pattern by the lamp unit 10 according to the presence of the preceding vehicle, and are added when the number of the preceding vehicles exceeds a predetermined threshold value. Limit the formation of light distribution patterns. The additional light distribution pattern is a light distribution pattern including a region above the cut-off line of the low beam light distribution pattern. Examples of the additional light distribution pattern include a high beam light distribution pattern Hi1, a left piece high light distribution pattern Hi2, a right piece high light distribution pattern Hi3, a split light distribution pattern, and a V beam light distribution pattern Lo3.

  Specifically, the irradiation controllers 228L and 228R form various light distribution patterns shown in FIG. 4 and the above-described split light distribution pattern according to the presence state of the preceding vehicle. Further, the irradiation controllers 228L and 228R acquire information on the preceding vehicle included in the image data captured by the camera 306 from the vehicle controller 302, and measure the number of the preceding vehicles included in one image data. Then, the irradiation controllers 228L and 228R determine that the number of front vehicles exceeds a predetermined threshold when the number of front vehicles included in the one image data exceeds a predetermined value. When the number of front vehicles exceeds a predetermined threshold value, the irradiation controllers 228L and 228R provide additional light distribution in which the height of at least a part of the cutoff line is lower than when the number of front vehicles is equal to or less than the threshold value. A restricted ADB mode for forming a pattern is implemented. Here, the “predetermined threshold value” is the result of an increase in the number of times the additional light distribution pattern is switched per unit time with an increase in the number of vehicles ahead. This is the number of vehicles ahead that will give glare to the vehicle ahead. This number can be set as appropriate based on experiments and simulations by the designer.

  For example, the irradiation control units 228L and 228R indicate that when the number of vehicles ahead is over a threshold, the detected presence state of the vehicle ahead is for the high beam light distribution pattern Hi1, the split light distribution pattern, and the left one high Even in a state where the light distribution pattern Hi2 or the right-side high light distribution pattern Hi3 can be formed, at least a part of the cut-off line is lower than these light distribution patterns. A light distribution pattern Lo3 is formed. Alternatively, the irradiation controllers 228L and 228R control the leveling actuator 226 to lower the optical axis of the lamp unit 10, thereby lowering the cut-off line height of the additional light distribution pattern according to the presence state of the preceding vehicle by a predetermined amount. Thus, an additional light distribution pattern having a relatively low cut-off line height may be formed. When an additional light distribution pattern with a low cut-off line height is formed by lowering the optical axis, the cut-off line height is high enough to reduce the possibility of giving the driver a sense of incongruity or giving glare to the vehicle ahead. For example, the entire cut-off line is lowered to a height below the horizontal line.

  Further, when the detected presence state of the front vehicle is a state in which the V-beam light distribution pattern Lo3 can be formed and the number of front vehicles exceeds the threshold value, the irradiation controllers 228L and 228R By forming the V-beam light distribution pattern Lo3 and controlling the leveling actuator 226 to lower the optical axis of the lamp unit 10, the height of at least a part of the cut-off line is lower than that of the V-beam light distribution pattern Lo3. A light distribution pattern for a cut-off line V-beam is formed. At this time, only the cut-off line height of one light distribution pattern of the basic low beam light distribution pattern Lo1L and the Dover low beam light distribution pattern Lo2R constituting the V beam light distribution pattern Lo3 may be lowered. When passing on the left side, it is preferable to lower the cut-off line height of the light distribution pattern Lo2R for the Dover low beam.

  When the number of front vehicles exceeds the threshold value, the above-described low cut-off offline V-beam light distribution pattern may be formed regardless of the presence state of the front vehicle. In other words, when the number of vehicles ahead exceeds the threshold value, switching of the additional light distribution pattern according to the presence state of the vehicle ahead is prohibited, so that driver discomfort and glare to the vehicle ahead are avoided. The same additional light distribution pattern in consideration may be formed. Further, as another light distribution pattern formed when the number of vehicles ahead exceeds the threshold value, a horizontal cut light distribution pattern having a cut-off line having the same height as the horizontal line may be formed. Good.

  As described above, as an additional light distribution pattern formation restriction, by forming an additional light distribution pattern having a low height at least a part of the cut-off line, there is a region where irradiation / non-irradiation is switched by switching the additional light distribution pattern. Decrease. Therefore, the possibility of giving the driver a sense of discomfort and discomfort can be reduced, and the possibility of giving glare to the preceding vehicle can be reduced.

  Further, as an additional light distribution pattern formation restriction, an additional light distribution pattern with lower illuminance than when the number of vehicles ahead exceeds a threshold value may be formed. Specifically, the irradiation controllers 228L and 228R form an additional light distribution pattern with lower illuminance than the case where the number of front vehicles is equal to or less than the threshold when the number of front vehicles exceeds the threshold. The restricted ADB mode is executed. For example, when the number of front vehicles exceeds a threshold value, the irradiation controllers 228L and 228R control the motor 238 and the like so as to form an optimum additional light distribution pattern according to the detected presence state of the front vehicle. . At the same time, the irradiation controllers 228L and 228R change the magnitude of the electric power output from the power supply circuit 230 to the bulb 14 so that the illuminance of the additional light distribution pattern becomes a predetermined low illuminance. In this way, an additional light distribution pattern with low illuminance is formed. Here, the “predetermined low illuminance” is illuminance in consideration not to give glare to the vehicle ahead, and can be set based on experiments and simulations by the designer.

  As described above, by forming the additional light distribution pattern with low illuminance as the formation restriction of the additional light distribution pattern, the illuminance difference in the region where irradiation / non-irradiation is switched by switching the additional light distribution pattern is reduced. Therefore, the possibility of giving the driver a sense of discomfort and discomfort can be reduced, and the possibility of giving glare to the preceding vehicle can be reduced.

  Furthermore, as a limitation on the formation of the additional light distribution pattern, the irradiation controllers 228L and 228R may prohibit the formation of the additional light distribution pattern when the number of front vehicles exceeds a threshold value. In this case, the basic low beam light distribution pattern Lo1 is formed.

  When an additional light distribution pattern having a low cut-off line height or illuminance is formed, the visibility of the driver can be improved compared to the basic low beam light distribution pattern Lo1, and the normal cut-off line height or illuminance can be reduced. The possibility of giving the driver a sense of discomfort and discomfort and the possibility of giving glare to the preceding vehicle can be reduced as compared with the case of forming the additional light distribution pattern. On the other hand, when the formation of the additional light distribution pattern is prohibited, the driver's visibility obtained is similar to that of the basic low beam light distribution pattern Lo1, but the driver may feel uncomfortable or uncomfortable. The possibility of giving glare to the image can be reduced more than when the cut-off line height or illuminance is lowered. Whether to form an additional light distribution pattern with low cut-off line height or low illuminance or prohibit the formation of the additional light distribution pattern, the driver ’s visibility, the driver's discomfort and discomfort, and the vehicle ahead Depending on the prevention of glare, it can be selected appropriately.

  In addition, as the formation limitation of the additional light distribution pattern, the reduction in the cut-off line height and the reduction in illuminance may be performed together. In this case, the control by the irradiation control units 228L and 228R is more complicated than the case where each is performed independently, but the driver feels more uncomfortable or uncomfortable than the case where each is performed independently, and the glare on the vehicle ahead. Can be further reduced.

  FIG. 5 is a control flowchart of automatic light distribution pattern formation control performed in accordance with the presence state and the number of vehicles ahead. This flow is repeatedly executed by the irradiation controllers 228L and 228R at a predetermined timing.

  First, the irradiation controllers 228L and 228R determine whether or not an instruction for controlling the automatic formation of a light distribution pattern has been made based on information obtained from the vehicle controller 302 (step 101: hereinafter abbreviated as S101). The same). If an instruction for automatic formation control has not been given (S101_No), this routine ends. When the automatic formation control instruction has been given (S101_Yes), the irradiation control units 228L and 228R determine whether the number of front vehicles exceeds a predetermined threshold based on the information obtained from the vehicle control unit 302. (S102).

  When the number of vehicles ahead exceeds the threshold value (S102_Yes), the irradiation controllers 228L and 228R perform the limited ADB mode including the above-described limitation of the additional light distribution pattern (S103). When the number of front vehicles does not exceed the threshold value (S102_No), the irradiation control units 228L and 228R form an additional light distribution pattern according to the presence of the front vehicle based on an instruction from the vehicle control unit 302. The normal ADB mode is executed (S104). Then, the irradiation controllers 228L and 228R determine whether an instruction to end automatic light distribution pattern formation control has been given based on the information obtained from the vehicle controller 302 (S105). The irradiation control units 228L and 228R end this routine when an end instruction is given (S105_Yes), and return to Step 102 when no end instruction is given (S105_No).

  The operations and effects of the configuration described above are summarized. In the vehicle headlamp device 200 according to the present embodiment, the additional light distribution pattern including the region above the cut-off line of the low beam light distribution pattern is controlled according to the presence and number of vehicles ahead. Specifically, when it is determined that the number of front vehicles exceeds a predetermined threshold, the formation of the additional light distribution pattern is restricted. As an additional light distribution pattern formation limitation, an additional light distribution pattern having a height at least a part of the cutoff line lower than that in the case where the number of front vehicles is equal to or less than the threshold value is formed. Alternatively, an additional light distribution pattern having lower illuminance than that in the case where the number of front vehicles is equal to or less than the threshold value is formed. Alternatively, the formation of the additional light distribution pattern is prohibited. As described above, when the formation of the additional light distribution pattern is restricted when the number of front vehicles exceeds the threshold, the number of front vehicles is large, and the additional light distribution pattern is switched when the additional light distribution pattern is switched in the normal ADB mode. In a situation where the light pattern frequently switches within a short time, which may cause the driver to feel visually uncomfortable or uncomfortable, the possibility of causing the driver to feel uncomfortable or uncomfortable can be reduced. . In addition, in the situation where the number of vehicles ahead is large, the presence of vehicles ahead is likely to be overlooked and the light distribution pattern switching is likely to be delayed, and it is difficult to form a light distribution pattern suitable for the vehicle ahead. The possibility of giving glare to the film can be reduced.

  In addition, when switching or formation of the additional light distribution pattern is prohibited, the number of times the bulb 14 is turned on in the ADB mode, the number of times the motor 238 that rotates the rotary shade 12 is driven, and the like can be reduced. Therefore, it is possible to save power and to extend the life of parts constituting the vehicle headlamp device 200 such as the bulb 14 and the motor 238, and to reduce the durability required for these parts. Can do.

(Embodiment 2)
The vehicle headlamp device according to the second embodiment determines that the number of vehicles ahead is over the threshold when the number of vehicles detected per unit time of the vehicle ahead exceeds a predetermined value. It differs from the first embodiment in that the formation restriction is performed. Hereinafter, this embodiment will be described. Note that the main configuration of the vehicle headlamp device, the shape of the light distribution pattern that can be formed, the mode of limiting the formation of the additional light distribution pattern, and the like are the same as those of the first embodiment, and therefore the same configuration as that of the first embodiment Are denoted by the same reference numerals, and description and illustration thereof are omitted as appropriate.

  FIG. 6 is a diagram for explaining the relationship between the number of detected vehicles per unit time of the front vehicle and the formation limitation of the additional light distribution pattern in the vehicle headlamp device according to the second embodiment. In the present embodiment, when the irradiation controllers 228L and 228R form a predetermined additional light distribution pattern by the lamp unit 10 according to the presence of the front vehicle, and the number of front vehicles exceeds a predetermined threshold value, Limit the formation of additional light distribution patterns.

  Specifically, the irradiation controllers 228L and 228R form various light distribution patterns shown in FIG. 4 and the above-described split light distribution pattern according to the presence state of the preceding vehicle. Further, the irradiation control units 228L and 228R acquire information on the preceding vehicle included in the image data captured by the camera 306 from the vehicle control unit 302, and measure the total number of the preceding vehicles per unit time. Then, when the total number of front vehicles per unit time exceeds a predetermined value, the irradiation controllers 228L and 228R determine that the number of front vehicles has exceeded the threshold, and limit the formation of additional light distribution patterns. Including restricted ADB mode. Here, the “predetermined value” can be appropriately set based on an experiment or simulation by a designer.

For example, as shown in FIG. 6, the number of front vehicles detected in a fixed time t (unit time) from time 0 to t ₁ exceeds n (predetermined value). Therefore, during the subsequent time t ₁ to t ₂ , the limited ADB mode including the additional light distribution pattern formation limitation is performed by the irradiation controllers 228L and 228R. Similarly, since the number of front vehicles exceeds n at a certain time t from time t ₁ to t ₂ , the limited ADB mode is performed during the subsequent time t ₂ to t ₃ . On the other hand, the additional light distribution pattern in accordance with for the number of the forward vehicle detected by the predetermined time t is less than n number, during the subsequent time t ₃ of t ₄ to the presence of the forward vehicle from time t ₂ to t ₃ A normal ADB mode is implemented to form Here, the “predetermined time t” and the number “n” can be appropriately set based on experiments and simulations by the designer.

  The additional light distribution pattern formation restriction performed in the restricted ADB mode is the same as in the first embodiment. Moreover, in this embodiment, the vehicle control part 302 and the camera 306 comprise the vehicle detection apparatus.

  FIG. 7 is a control flowchart of automatic light distribution pattern formation control performed according to the presence state and the number of vehicles ahead in the second embodiment. This flow is repeatedly executed by the irradiation controllers 228L and 228R at a predetermined timing.

  First, the irradiation controllers 228L and 228R determine whether an automatic light distribution pattern formation control instruction has been given based on the information obtained from the vehicle controller 302 (S201). When the instruction for the automatic formation control has not been given (S201_No), this routine ends. When the automatic formation control instruction has been given (S201_Yes), the irradiation controllers 228L and 228R perform the normal ADB mode (S202), and based on the information on the preceding vehicle obtained from the vehicle controller 302, the preceding vehicle Is started to be accumulated (S203).

  Then, the irradiation control units 228L and 228R determine whether or not a certain time t has elapsed since the start of integration (S204). If the certain time t has not elapsed (S204_No), the irradiation control units 228L and 228R The integration of the number is repeated (S203). If the predetermined time t has elapsed (S204_Yes), the irradiation controllers 228L and 228R determine whether the cumulative number of vehicles ahead has exceeded a predetermined value (S205). When the cumulative number of vehicles ahead has exceeded the predetermined value (S205_Yes), the irradiation controllers 228L and 228R determine that the number of vehicles ahead has exceeded the threshold value, and implement the restricted ADB mode (S206). When the cumulative number of vehicles ahead does not exceed the predetermined value (S205_No), the irradiation controllers 228L and 228R perform the normal ADB mode (S207).

  Thereafter, the irradiation controllers 228L and 228R reset the integration of the number of vehicles ahead (S208), and based on the information obtained from the vehicle controller 302, determines whether an instruction to end automatic light distribution pattern formation has been issued. (S209). The irradiation control units 228L and 228R end this routine when the end instruction is given (S209_Yes), and return to Step 203 when the end instruction is not given (S209_No).

  The configuration of the present embodiment described above can also reduce the possibility of giving the driver a sense of discomfort and discomfort, and the possibility of giving glare to the preceding vehicle. Further, in the vehicle headlamp device 200 according to the present embodiment, when the number of detected vehicles per unit time of the preceding vehicle exceeds a predetermined value, it is determined that the number of the preceding vehicle has exceeded a threshold value and additional distribution is performed. The optical pattern formation restriction is implemented. Therefore, the vehicle headlamp device 200 of this embodiment measures the number of front vehicles included in one image data and implements the additional light distribution pattern in comparison with the first embodiment that restricts the formation of the additional light distribution pattern. Although it takes time to determine whether or not to limit the formation of the vehicle, it is possible to more accurately grasp a state in which the driver may feel uncomfortable or may cause glare to the preceding vehicle. For example, if the vehicle 306 frequently enters and exits the shooting range of the camera 306, and the number of vehicles entering and the number of vehicles leaving the vehicle is approximately the same, the number of vehicles ahead detected by the camera 306 is Although it may be below the threshold value, even in such a case, there is a possibility that the driver may feel uncomfortable or uncomfortable due to frequent switching of the additional light distribution pattern, or may cause glare to the vehicle ahead. According to the vehicle headlamp device 200 of the present embodiment, the formation of the additional light distribution pattern can be appropriately limited even in such a situation.

(Embodiment 3)
In the vehicle headlamp device according to the third embodiment, when the number of times of control per unit time in the formation control of the additional light distribution pattern according to the presence of the preceding vehicle exceeds a predetermined value, the number of the preceding vehicles is a threshold value. This is different from the first and second embodiments in that it is determined that the additional light distribution pattern is limited. Hereinafter, this embodiment will be described. Since the main configuration of the vehicle headlamp device, the shape of the light distribution pattern that can be formed, the control flow, and the like are the same as those of the first or second embodiment, the same configuration as that of the first or second embodiment is the same. The description and illustration are omitted as appropriate.

  FIG. 8 is a diagram for explaining the relationship between the number of formations of the additional light distribution pattern and the formation restriction of the additional light distribution pattern in the vehicle headlamp device according to the third embodiment. In the vehicle headlamp device 200 according to the present embodiment, the irradiation controllers 228L and 228R form a predetermined additional light distribution pattern by the lamp unit 10 according to the presence of the front vehicle, and the number of the front vehicles is predetermined. When the threshold value is exceeded, the formation of the additional light distribution pattern is limited. In the present embodiment, the irradiation controllers 228L and 228R form only the high beam light distribution pattern Hi1 as the additional light distribution pattern. Therefore, in the present embodiment, in the ADB mode in which the additional light distribution pattern is formed according to the presence of the vehicle ahead, the formation / non-formation switching of the high beam light distribution pattern Hi1, that is, the basic low beam light distribution pattern Lo1 and the high beam Switching to the light distribution pattern Hi1 is performed.

  Specifically, the irradiation controllers 228L and 228R form a basic low beam light distribution pattern Lo1 and a high beam light distribution pattern Hi1 in accordance with the presence state of the vehicle ahead. Further, the irradiation controllers 228L and 228R, for example, detect the signal transmitted to the variable shade controller 232 in order to form the additional light distribution pattern, thereby accumulating the number of times the additional light distribution pattern is formed. The number of times of formation of the additional light distribution pattern corresponds to the number of times of control in the formation control of the additional light distribution pattern. When the number of times the additional light distribution pattern is formed exceeds a predetermined value, the irradiation controllers 228L and 228R determine that the number of front vehicles has exceeded the threshold value, and include the formation restriction of the additional light distribution pattern. Implement restricted ADB mode. Here, the “predetermined value” can be appropriately set based on an experiment or simulation by a designer. In addition, the number of formation cancellations of the additional light distribution pattern, not the number of formations of the additional light distribution pattern, in other words, the number of times of illuminance reduction of the additional light distribution pattern may be integrated. This corresponds to the number of times the light pattern is controlled.

For example, as shown in FIG. 8, the number of additional light distribution patterns formed in _a certain time t _a (unit time) from time 0 to t ₁ exceeds m (predetermined value). Therefore, during the subsequent limited formation time t _b from time t ₁ to t ₂ , the limited ADB mode including the formation limitation of the additional light distribution pattern is performed by the irradiation controllers 228L and 228R. The limited ADB mode is performed after the high-beam light distribution pattern Hi1 formed at the (m + 1) th time is switched to the basic low-beam light distribution pattern Lo1. When the limit formation time t _b elapses, with the normal ADB mode is performed instead of the limit ADB mode, the integration of the formation number of additional light distribution pattern is resumed. After restarting the integration of the number of times of formation of the additional light distribution pattern, the number of times of formation of the additional light distribution pattern is less than or equal to m at _a certain time ta from time t ₂ to t _3, and therefore between time t ₃ and t ₄ Usually, the ADB mode is implemented. Here, the “predetermined time t _a ”, the “limitation formation time t _b ”, and the number of times “m” can be appropriately set based on experiments and simulations by the designer.

In addition, between _{t 3} from the time _{t 2,} passing switch is ON / OFF (not shown) provided in the vehicle 300. In this case, a passing signal is transmitted from the vehicle control unit 302 to the irradiation control units 228L and 228R, and the irradiation control units 228L and 228R form a high beam light distribution pattern Hi1 as a passing light distribution pattern according to the passing signal. As described above, the additional light distribution pattern is also formed by the operation of the passing switch. However, the irradiation controllers 228L and 228R perform the formation of the additional light distribution pattern based on the passing signal from the formation of the additional light distribution pattern in the ADB mode. Separately, the number of formations of the additional light distribution pattern is not integrated.

  The additional light distribution pattern formation restriction performed in the restricted ADB mode is the same as in the first embodiment. In the present embodiment, only the high beam light distribution pattern Hi1 is formed as the additional light distribution pattern. However, another additional light distribution pattern shown in FIG. 4 or the like may be formed. In this case, switching from one additional light distribution pattern to another additional light distribution pattern is also integrated as the number of times the additional light distribution pattern is formed. That is, the number of times of switching the additional light distribution pattern is included in the number of times of control in the formation control of the additional light distribution pattern.

  FIG. 9 is a control flowchart of automatic light distribution pattern formation control performed according to the presence state and the number of vehicles ahead in the third embodiment. This flow is repeatedly executed by the irradiation controllers 228L and 228R at a predetermined timing.

  First, the irradiation controllers 228L and 228R determine whether an automatic light distribution pattern formation control instruction has been issued based on the information obtained from the vehicle controller 302 (S301). When the instruction for automatic formation control has not been given (S301_No), this routine is terminated. When the automatic formation control instruction has been given (S301_Yes), the irradiation controllers 228L and 228R perform the normal ADB mode (S302), and start integrating the number of formations of the additional light distribution pattern (S303).

Then, the irradiation controller 228L, 228R determines whether elapsed predetermined time _{t a} from the integration start (S304). If not elapsed for a predetermined time _{t a} (S304_No), repeats the integration of the formation number of additional light distribution pattern to the predetermined time _{t a} has passed (S303). If you have passed the predetermined time _{t a} (S304_Yes), the irradiation controller 228L, 228R is integration of forming the number of additional light distribution pattern is determined whether or exceeds a predetermined value (S305). When the total number of additional light distribution pattern formations exceeds a predetermined value (S305_Yes), the irradiation controllers 228L and 228R determine that the number of vehicles ahead exceeds the threshold value, and perform the restricted ADB mode. (S306). Then, the irradiation controller 228L, 228R determines whether elapsed limit formation time _{t b} (S307), if not yet passed the limit formation time _{t b} (S307_No), carried out continuously restricted ADB mode ( S306). On the other hand, if the cumulative number of additional light distribution patterns has not exceeded the predetermined value (S305_No), the irradiation controllers 228L and 228R perform the normal ADB mode (S308).

If you have passed the limit formation time _{t b} in step 307 (S307_Yes), or, when carrying out the normal ADB mode (S308), the irradiation controller 228L, 228R may resets the integrated formation number of additional light distribution pattern (S309). Then, the irradiation controllers 228L and 228R determine whether an instruction to end automatic light distribution pattern formation control has been given based on the information obtained from the vehicle controller 302 (S310). The irradiation control units 228L and 228R end this routine when an end instruction is given (S310_Yes), and return to step 302 when no end instruction is given (S310_No).

  The configuration of the present embodiment described above can also reduce the possibility of giving the driver a sense of discomfort and discomfort, and the possibility of giving glare to the preceding vehicle. Further, in the vehicle headlamp device 200 according to the present embodiment, the number of front vehicles when the number of times of control per unit time in the formation control of the additional light distribution pattern according to the presence of the front vehicle exceeds a predetermined value. Therefore, the formation of the additional light distribution pattern is restricted. Therefore, as in the second embodiment, the formation restriction of the additional light distribution pattern is implemented in comparison with the first embodiment in which the number of front vehicles included in one image data is measured and the formation restriction of the additional light distribution pattern is implemented. Although it takes time to determine whether or not, it is possible to more accurately grasp a state in which the driver may feel uncomfortable or may cause glare to the preceding vehicle.

  The present invention is not limited to the above-described embodiments, and it is possible to combine the embodiments or to add various modifications such as design changes based on the knowledge of those skilled in the art. Embodiments to which modifications are made are also included in the scope of the present invention. Each of the above-described embodiments and a new embodiment resulting from the combination of each of the above-described embodiments and the following modified examples have the effects of the combined embodiments and modified examples.

  In the above-described first to third embodiments, the number of vehicles ahead is monitored using the detection result of the vehicle detection device including the camera 306 and the vehicle control unit 302. However, the method for determining the number of vehicles ahead is not particularly limited to this. For example, when traffic information is obtained from the navigation system 314 and the vehicle ahead is congested, the number of vehicles ahead is a predetermined threshold. It may be determined that the value has been exceeded.

  Further, in each of the above-described embodiments, the irradiation control units 228L and 228R determine that the presence state of the preceding vehicle and the number of preceding vehicles have exceeded the threshold value, but the vehicle control unit 302 performs these determinations. You may make it perform. In this case, the irradiation controllers 228L and 228R control turning on / off of the bulb 14 and driving of the swivel actuator 222 and the motor 238 based on an instruction from the vehicle controller 302.

  10 lamp unit, 14 bulb, 200 vehicle headlamp device, 210L, 210R headlamp unit, 228, 228L, 228R irradiation control unit, 300 vehicle, 302 vehicle control unit, 306 camera.

Claims (4)

A lamp unit capable of forming an additional light distribution pattern including a region above the cut-off line of the low beam light distribution pattern;
A control unit that controls the irradiation of light by the lamp unit according to the presence of a vehicle ahead,
The controller is
When the number of vehicles in front exceeds a predetermined threshold, the formation of the additional light distribution pattern is limited,
When the number of control per unit time in the formation control of the additional light distribution pattern according to the presence of the preceding vehicle exceeds a predetermined value, it is determined that the number of preceding vehicles exceeds the threshold value,
The vehicle headlamp device according to claim 1, wherein the restriction is released after a predetermined time has elapsed since the restriction on the formation of the additional light distribution pattern was started. The control unit, when the number of front vehicles exceeds the threshold value, the additional light distribution pattern in which at least a part of the cut-off line has a lower height than when the number of front vehicles is the threshold value or less. The vehicle headlamp device according to claim 1, wherein: The controller forms an additional light distribution pattern having lower illuminance than when the number of vehicles ahead is less than or equal to the threshold value when the number of vehicles ahead is greater than the threshold value. The vehicle headlamp device according to claim 1 or 2 . The vehicle headlamp device according to claim 1, wherein the control unit prohibits the formation of the additional light distribution pattern when the number of vehicles ahead is greater than the threshold value.

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