JP2013001234A - Head light control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head light control device for a vehicle, which can avoid dazzling in the vehicle even in a state where a light distribution method is not unified and can also improve the visibility of the front area of the vehicle.SOLUTION: The head light control device for a vehicle includes: a light distribution control means ECU which controls the head lights LHL, RHL of an own vehicle by a predetermined light distribution method; and a light distribution determining means PD+ECU which determines the light distribution method of the head lights in other vehicles. When it is determined that the light distribution method in other vehicle is different from that of the own vehicle, the light distribution control method ECU changes and controls the light distribution of the head lights of the own vehicle.

Description

  The present invention relates to a headlamp control device for controlling the lighting state and light distribution of a headlamp of a vehicle such as an automobile.

  Controls the lighting condition and light distribution of the headlight of the vehicle in order to improve the visibility of the front area of the vehicle and prevent dazzling of the preceding and oncoming vehicles, especially the oncoming vehicle in front of the vehicle. There has been proposed a headlight control device as described above. One of them is a polarization-type headlamp control device using polarized light described in Patent Document 1. In the technique of Patent Document 1, the irradiation light emitted from the headlight of the own vehicle is polarized and the wavelength band is limited, and the driver of the own vehicle has the polarization and the wavelength band corresponding to the irradiation light emitted from the own vehicle. It is configured to visually recognize light. Therefore, it is possible to visually recognize the front area of the vehicle irradiated with the headlight of the own vehicle, while preventing the driver of the own vehicle from being dazzled by the light emitted from the headlight of the oncoming vehicle It is said.

  In addition, as another one, a wide area in front of the host vehicle is divided into a plurality of divided areas (zones) and light irradiation is performed for each zone. There is a headlight control device that is abbreviated as an ADB (Adaptive Driving Beam) system that performs light distribution control by controlling. For example, in Patent Document 2, a liquid crystal plate in which light transmitting elements are arranged in a matrix is arranged on the front side of a lamp light source, and light emitted from the lamp light source is controlled by independently controlling the light transmittance of the light transmitting elements of the liquid crystal plate. Is controlled for each light transmitting element to control the light distribution pattern by the light transmitted through each light transmitting element. Thereby, while suppressing the irradiation light amount to the zone where the oncoming vehicle exists, the irradiation light amount in a wide zone where the oncoming vehicle does not exist can be increased, and a light distribution equivalent to that of the high beam can be obtained.

JP 61-291215 A JP-A-1-244934

The technique of Patent Document 1 functions effectively when the headlight control devices of the host vehicle and the oncoming vehicle have the same polarization method, but the headlight control device of the oncoming vehicle does not employ the polarization method. In some cases, the oncoming vehicle may be dazzled by the light emitted from the vehicle. The technique of Patent Document 2 can also prevent the own vehicle from being dazzled with respect to the oncoming vehicle, but if the oncoming vehicle does not adopt the same ADB method as the own vehicle, the own vehicle is irradiated with the irradiation light of the oncoming vehicle. It is impossible to avoid being dazzled. In both cases of Patent Documents 1 and 2, since the oncoming vehicle normally travels with a low beam light distribution, it is possible to avoid serious dazzling in the own vehicle, but the oncoming vehicle has a low beam light distribution. However, since it cannot be completely avoided that the own vehicle receives some illusion, the visibility of the front area of the own vehicle is reduced by this dazzling. As described above, the techniques of Patent Documents 1 and 2 are effective when all the vehicles are equipped with the headlamp control device of the same method of either the polarization method or the ADB method. As described above, the problem of conflicting between avoidance of dazzling in the own vehicle and oncoming vehicle and ensuring visibility in the front area is solved as described above. It is difficult to do.

  An object of the present invention is to provide a headlamp control device capable of avoiding dazzling in a vehicle even in a situation where the light distribution control method is not unified, and at the same time improving the visibility of the front area of the vehicle. is there.

The vehicle headlamp control device according to the present invention includes a light distribution control means for controlling the headlamp of the own vehicle by a predetermined light distribution control method, and a light distribution for determining the light distribution control method of the headlamp in another vehicle. And a light distribution control means for changing and controlling the light distribution of the headlight of the own vehicle when it is determined that the light distribution control method of the other vehicle is different from the light distribution control method of the own vehicle. Features. For example, as a preferred form of the present invention, the light distribution control method of the own vehicle is a polarization method, and the light distribution control means is configured to perform a control to shield a region where another vehicle exists in the front region of the own vehicle. Alternatively, as another preferred mode, the light distribution control method of the own vehicle is an AZB method, and the light distribution control means performs control to increase the irradiation light intensity in a region where no other vehicle exists in the front region of the own vehicle. .

  The light distribution determination means in the present invention includes a light detection means for detecting the irradiation light of another vehicle, an image analysis means for analyzing an image obtained by imaging the other vehicle, and an inter-vehicle communication means based on information obtained by communication with the other vehicle. It is comprised including at least one.

  According to the present invention, when the light distribution control method of another vehicle such as an oncoming vehicle existing ahead of the own vehicle is determined to be different from the light distribution control method of the own vehicle, the light distribution of the own vehicle is set in advance. By controlling to, dazzling with respect to other vehicles is avoided, and the visibility of the front area of the own vehicle is improved. For example, when the light distribution control method of the own vehicle is a polarization method, the area where the other vehicle exists is shielded from light while avoiding dazzling of the other vehicle while ensuring the visibility of the front area of the own vehicle. In addition, when the light distribution control method of the own vehicle is the ADB method, the illumination intensity of the front region of the own vehicle where the other vehicle does not exist is increased while avoiding dazzling of the other vehicle to improve the visibility of the front region. To do.

The schematic block diagram of Embodiment 1 to which this invention is applied. FIG. 3 is a cross-sectional view of the headlamp according to the first embodiment. The partial exploded perspective view which shows the conceptual structure of a light distribution control board. The conceptual block diagram of a polarization detector. FIG. 5 is a diagram for explaining a light distribution control operation according to the first embodiment. The schematic block diagram of Embodiment 2 to which this invention is applied. Sectional drawing of the headlamp of Embodiment 2. FIG. FIG. 10 is a diagram for explaining a light distribution control operation according to the second embodiment.

(Embodiment 1)
Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a conceptual configuration diagram of Embodiment 1 in which the headlamp control device of the present invention is applied to an automobile as a headlamp device adopting a deflection method. Headlights, that is, a left headlamp LHL and a right headlamp RHL are provided on the left and right of the front part of the car CAR. These headlamps LHL and RHL are turned on / off and light distribution by a light distribution control unit ECU comprising an electronic control circuit. A polarizing filter PF is disposed on the front side of the driver's seat, for example, on the windshield, and the front area of the vehicle is viewed through the polarizing filter PF. In addition, a polarization detector PD for detecting light emitted from the oncoming vehicle is disposed at the front of the host vehicle, and outputs a detection signal to the light distribution control unit ECU.

FIG. 2 is a schematic configuration diagram of the left and right headlamps LHL and RHL, and the configuration of both headlamps is the same. The light source 1 is disposed at the first focal point F1 of the spheroid reflector 2, and the light distribution control plate 3 is disposed at a position near the second focal point F2. Further, on the front side, there is disposed an irradiation lens 4 made of a convex lens whose rear focal point is substantially coincident with the second focal point by a cylindrical holder 5. Here, the light source 1 is composed of two LEDs (light emitting diodes) 12 supported on the upper surface and the lower surface of the stem 11 supported by the reflector 2 along the lamp optical axis Lx, and each LED 12 emits light. The light emitted from time to time is projected onto the reflector 2. The light source 1 may be a bulb (light bulb). When the headlamps LHL and RHL are turned on, the light emitted from each LED 12 is reflected by the reflector 2 and collected at the second focal point F2, and then transmitted through the light distribution control plate 3 and further directed forward by the irradiation lens 4. Is irradiated. At this time, it is possible to irradiate the front with an arbitrary light distribution pattern by shielding part of the light transmitted through the light distribution control plate 3.

  As shown in a partially exploded view in FIG. 3, the light distribution control plate 3 has light transmitting element electrodes 34 and 35 which are paired on both surfaces of the liquid crystal plate 33, and a pair of light incident side and light output side on both outer surfaces. Polarizing plates 31 and 32 are disposed, and these are integrated in a laminated state. Each of the light transmitting element electrodes 34 and 35 is formed of a transparent conductive plate, one electrode 34 is formed as one common electrode disposed over almost the entire surface of the liquid crystal plate 33, and the other electrode 35 is liquid crystal. It is configured as a large number of matrix electrodes arranged in a grid pattern (matrix) over almost the entire surface of the plate 33. A predetermined potential can be applied to the common electrode 34 and each matrix electrode 35 from the light distribution control unit ECU. The pair of polarizing plates 31 and 32 are related to each other so as to have a predetermined polarization axis direction. Here, the polarizing axes of both the polarizing plates 31 and 32 are directed in the vertical direction. It is oriented in the same direction as the polarization axis of the filter PF.

When no potential is applied between the common electrode 34 and the matrix electrode 35, the light distribution control plate 3 transmits the polarizing plate 31 on the light incident side and the polarized light whose polarization axis is directed in the vertical direction passes through the liquid crystal plate 33. Then, the light is further transmitted through the polarizing plate 32 on the light output side and emitted. On the other hand, when a potential is applied between the common electrode 34 and the matrix electrode 35, the polarized light that has passed through the incident-side polarizing plate 31 is rotated by 90 degrees when passing through the liquid crystal plate 33. The polarizing plate 32 on the side is not transmitted. Therefore, by controlling the application of potentials to a large number of matrix electrodes 35 in the light distribution control unit ECU, light emitted from the light source 1 in the matrix electrodes 35 to which the potentials are applied is prevented from being irradiated forward. As a result, both headlamps LHL and RHL can irradiate polarized light with an arbitrary light distribution pattern.

4A, the polarization detector PD includes a horizontal polarizing plate 101 and a vertical polarizing plate 102 that are arranged in parallel with the polarization axes different from each other by 90 degrees, and each of the polarizing plates 101 and 102. A pair of light receivers 111 and 112 that are disposed behind and detect the amount of polarized light transmitted through each polarizing plate as a voltage, an adder 121 that adds both voltages detected by both light receivers 111 and 112, and both voltages A subtractor 122 for subtracting is provided. According to this polarization detector, as shown in FIG. 4B, the subtraction output Vd of the subtractor 122 is changed in accordance with the direction of the polarization axis of the incident polarized light, that is, the angle of the polarization axis with respect to the vertical direction. The That is, here, the maximum value is obtained when the polarization axis of the polarized light is 0 ° (horizontal direction), and the minimum value is obtained when the polarization axis is 90 ° (vertical direction). When the output Vd of the subtractor 122 is 0, the received light is detected as unpolarized light. Note that the subtraction output Vo takes the maximum and minimum intermediate values according to the change in the angle of the polarization axis, and may be 0. However, in the polarization method to which the present invention is applied, the polarization axis is either horizontal or vertical. Therefore, the subtracted output Vd does not become 0, and therefore it is possible to detect whether or not the received light is polarized. Further, as shown in FIG. 4C, the addition output Va of the adder 121 is a characteristic that increases as the oncoming vehicle approaches the own vehicle regardless of whether the irradiation light of the oncoming vehicle is polarized or not. is there.

  In the headlamp control apparatus according to the first embodiment, it is possible to perform illumination using the conventional polarization method. That is, the light distribution control unit ECU causes the light sources 1 of the left and right headlamps LHL and RHL to emit light, and at the same time, does not apply a potential to the light distribution control plate 3. Thereby, the light emitted from the light source 1 is reflected by the reflector 2, then passes through the light distribution control plate 3, and is irradiated toward a wide front area by the irradiation lens 3. For example, as shown in FIG. 5A, a region Aa corresponding to high beam distribution is irradiated. At this time, the light emitted from both headlamps LHL and RHL is polarized by the light distribution control plate 3 along the polarization axes of the polarizing plates 31 and 32. On the other hand, when the polarized light irradiated forward is reflected by the front road surface, or an oncoming vehicle or a preceding vehicle, in this case, oncoming vehicle CAR1, this reflected polarized light has the same polarization axis as the polarization axis of the polarization filter PF of the own vehicle. Therefore, the vehicle is transmitted through the polarizing filter PF, and the passenger of the own vehicle can visually recognize the oncoming vehicle CAR1. At this time, the oncoming vehicle CAR1 is also provided with the same polarization type headlamp control device, and if the direction of the polarization axis at that time is different from that of the own vehicle, the irradiation light of the oncoming vehicle CAR1 is the polarization filter of the own vehicle. Since the PF does not pass through, the passenger of the own vehicle is not dazzled by the irradiation light of the oncoming vehicle CAR1, and the passenger of the oncoming vehicle CAR1 is not dazzled by the irradiation light of the own vehicle for the same reason.

  However, as described above, when the oncoming vehicle is not equipped with the polarization type headlamp control device, there is a possibility that the passenger of the oncoming vehicle may be dazzled by the light emitted from the own vehicle. On the other hand, in order to avoid dazzling the vehicle by checking the vehicle in the oncoming vehicle, the vehicle usually travels with a low beam light distribution, but even with this low beam light distribution, some dazzling occurs in the vehicle. Therefore, the visibility ahead of the host vehicle may be reduced by this dazzling. Further, even when the oncoming vehicle is equipped with a polarization type headlamp control device, the own vehicle and the oncoming vehicle may be dazzled with each other when the polarization axis thereof coincides with the polarization axis of the own vehicle. In this way, when there is a possibility of dazzling in the own vehicle or the oncoming vehicle, the polarization detector PD of the own vehicle detects the irradiation light of the oncoming vehicle, whether or not the irradiation light of the oncoming vehicle is polarized, or polarization In this case, the direction of the polarization axis is detected. When it is detected that the light emitted from the oncoming vehicle is polarized light having a polarization axis in a direction different from that of the own vehicle, as described above, each of the own vehicle and the oncoming vehicle is not likely to be dazzled. No control is performed to avoid dazzling.

On the other hand, based on the detection by the polarization detector PD, the oncoming vehicle approaches the host vehicle as shown in FIG. 4C, and the added output Va exceeds the predetermined threshold value Vt. Based on the subtraction output Vd shown in FIG. 4B, when it is detected that the irradiation light of the oncoming vehicle is not polarized, and even if the irradiation light of the oncoming vehicle is polarized, the direction of the polarization axis is the same as the polarization axis of the own vehicle. Is detected, the light distribution control unit ECU executes control for avoiding dazzling. That is, the light distribution control unit ECU applies a potential to the specific matrix electrode 35 of each light distribution control plate 3 of the left and right headlamps LHL and RHL. Here, as shown in FIG. 5B, when the front area of the host vehicle is divided into the first to fourth quadrants, the first quadrant to the upper quadrant with a high probability that the oncoming vehicle CAR1 exists is present. A predetermined potential is applied to the matrix electrode 35 corresponding to the region Ab including a part. Thereby, the polarization axis is rotated in the region of the liquid crystal plate 33 where the matrix electrodes 35 corresponding to the partial regions of the first quadrant and the fourth quadrant are arranged, and the matrix electrode 35 emits light from the light source 1. In other words, the light is not shielded forward, that is, it is shielded. Thereby, the dazzling with respect to the oncoming vehicle CAR1 can be prevented. On the other hand, since the irradiation to the second to fourth quadrants is almost ensured, even if the vehicle is slightly dazzled by the low beam distribution of the oncoming vehicle CAR1, light irradiation in a wide area in the front area can be ensured. Visibility can be improved compared with the case where a vehicle performs light irradiation with a low beam light distribution.

  In this embodiment, the oncoming vehicle is detected by detecting the irradiation light of the oncoming vehicle with the polarization detector PD, but when an imaging camera or the like for detecting the position of the oncoming vehicle is provided, By applying a potential only to the matrix electrode at a position corresponding to the detected oncoming vehicle, a so-called ADB method can be realized, and only the area where the oncoming vehicle exists is shielded to prevent the oncoming vehicle from being dazzled. By irradiating the front area with light, the visibility of the front area can be further enhanced.

(Embodiment 2)
FIG. 6 is a conceptual configuration diagram of the second embodiment applied to a headlight control device adopting an ADB method as a light distribution control method of the present invention, and the same reference numerals are given to the parts equivalent to the first embodiment. . A left headlamp LHL and a right headlamp RHL are disposed on the left and right of the front portion of the car CAR. The headlamps LHL and RHL are turned on / off and light distribution by the light distribution control unit ECU. An imaging camera CAM for imaging the front area is disposed in front of the own vehicle CAR, and an image captured by the imaging camera CAM is output to the light distribution control unit ECU. Furthermore, the own vehicle is provided with an inter-vehicle communication device TRX capable of transmitting and receiving various information to and from an oncoming vehicle, and is configured to input and output the information to and from the light distribution control unit ECU. Yes. In the second embodiment, the vehicle CAR does not include the polarizing filter PF and the polarization detector PD of the first embodiment.

As shown in FIG. 7, the left and right headlamps LHL and RHL are substantially the same as those of the first embodiment, and include a light source 1, a reflector 2, a light distribution control plate 3, and an irradiation lens 4. 6 is provided. The auxiliary light source 6 includes an auxiliary LED 61 provided at a position out of the first focus F1, and an auxiliary reflector 62 that reflects light emitted from the auxiliary LED 61 forward in a required light beam state. When the auxiliary light source 6 is turned on, the light emitted from the auxiliary light source 6 is irradiated toward the front left region through the irradiation lens 4.

The light distribution control unit ECU controls the application of potentials to the light distribution control plates 3 of the headlamps LHL and RHL as well as the lighting / extinction of the auxiliary light source 6 as in the first embodiment. Further, the light distribution control unit ECU may detect an oncoming vehicle by analyzing an image captured by the imaging camera CAM, and detect a position of the detected oncoming vehicle, that is, a coordinate position in a front area of the own vehicle. Is possible. Further, the light distribution control unit ECU transmits information that the own vehicle adopts the ADB method to the other vehicle by the inter-vehicle communication device TRX, and at the same time, from the signal received by the inter-vehicle communication device TRX, It is possible to determine whether the oncoming vehicle adopts the ADB method.

In the headlamp control device of the second embodiment, the light distribution control unit ECU emits the light sources 1 of the left and right headlamps LHL and RHL and simultaneously detects the position of the oncoming vehicle based on the image captured by the imaging camera CAM. Further, it is determined whether the headlight control device of the oncoming vehicle is of the ADB system based on the reception of information by the inter-vehicle communication device TRX. As shown in FIG. 8A, when it is determined that the oncoming vehicle CAR1 adopts the ADB method, the light distribution control unit ECU controls the light distribution control plates 3 of the left and right headlamps LHL and RHL. A potential is supplied to the matrix electrode 35 corresponding to the oncoming vehicle position detected by the imaging camera CAM. As a result, the polarization axis is rotated in the region of the liquid crystal plate 33 of the matrix electrode 35 corresponding to the oncoming vehicle CAR1, and the light emitted from the light source is shielded from the electrodes without being irradiated forward. Thus, the area Ac including the oncoming vehicle CAR1 is shielded from light, and dazzling of the oncoming vehicle CAR1 can be prevented. On the other hand, since irradiation with respect to area | region Aa except the said area | region Ac is ensured, the light irradiation of the wide area | region of a front area | region can be ensured, and the visibility in the own vehicle can be improved.

On the other hand, when it is determined in the light distribution control unit ECU that the oncoming vehicle CAR1 does not employ the ADB method, the matrix electrodes 35 for applying a voltage to the light distribution control plates 3 of the left and right headlamps LHL and RHL are somewhat This increases to increase the light shielding area Ad, so that the dazzling of the oncoming vehicle CAR1 can be reliably prevented. For example, the light shielding region Ad may be expanded to a partial region of the first quadrant and the fourth quadrant as in the first embodiment. The enlargement of the light-shielding area is not necessarily required, and is performed, for example, during high-speed traveling or the like according to the traveling state of the host vehicle. On the other hand, the light distribution control unit ECU lights the auxiliary light sources 6 of the left and right headlamps LHL and RHL to illuminate the left side area of the front area of the vehicle, for example, a partial area of the second quadrant and a third quadrant area. The irradiation light intensity of the front left area Ae of the vehicle is increased. That is, when the oncoming car CAR1 does not adopt the ADB system, it is estimated that the oncoming car CAR1 has a low beam light distribution, and this low beam light distribution causes not less dazzling than the ADB system in the own vehicle. By increasing the irradiation light intensity in the three-quadrant area, it is possible to secure light irradiation in a wide area in the front area of the own vehicle, and it is possible to improve visibility compared to the case where the own vehicle performs light irradiation with low beam light distribution.

  In this second embodiment, it is determined whether or not the headlight control device of the oncoming vehicle adopts the ADB method by inter-vehicle communication. However, the irradiation light of the oncoming vehicle is based on the image captured by the imaging camera of the own vehicle. By detecting the light intensity and the light intensity distribution, it is possible to determine whether or not the oncoming vehicle is irradiating the ADB method, and based on this, it is possible to determine the method of the headlamp control device of the oncoming vehicle. In this way, appropriate headlamp control can be realized by the vehicle alone.

  In the second embodiment, the auxiliary light source is used to increase the luminous intensity of the front left region of the vehicle, but the light emitted from the light source such as a galvano mirror is divided into a number of light beams in the headlamp, and In the case of a headlamp control device configured to obtain a desired light distribution pattern by controlling the irradiation direction of the divided light beam, the optical axis control is performed so that the divided light beam directed to the oncoming vehicle is directed to the left front area. By doing so, it is possible to achieve light distribution control that increases the luminous intensity of the front left area of the host vehicle while avoiding dazzling oncoming vehicles. In this case, since the light emitted from the light source is not shielded, it is effective in improving the light utilization efficiency and reducing the power consumption.

  Further, in the first embodiment, the other vehicle may be shielded at the same time, and at the same time as in the second embodiment, the control may be performed to increase the irradiation light intensity in a region where no other vehicle exists.

  The present invention is a vehicle in which the headlamp is turned on / off and the light distribution is controlled so as to improve the visibility of the front area of the host vehicle while avoiding dazzling oncoming vehicles as in the polarization method and the ADB method. It is possible to apply to the headlamp control device of the above.

CAR Own vehicle CAR1 Oncoming vehicle LHL, RHL Headlamp ECU Light distribution control unit PF Polarization filter PD Polarization detector CAM Imaging camera TRX Inter-vehicle communication device 1 Light source 2 Reflector 3 Light distribution control plate 4 Irradiation lens 6 Auxiliary light source 12 LED
31, 32 Polarizing plate 33 Liquid crystal plate 34, 35 Light transmitting element electrode 61 Auxiliary LED
62 Auxiliary reflectors 101 and 102 Polarizing plates 111 and 112 Light receiver 121 Adder 122 Subtractor

Claims (4)

  A light distribution control means for controlling the headlight of the own vehicle by a predetermined light distribution control method, and a light distribution determination means for judging the light distribution control method of the headlight in another vehicle, the light distribution control means, A vehicle headlamp control apparatus that controls change of the light distribution of a headlight of a host vehicle when it is determined that the light distribution control method of another vehicle is different from the light distribution control method of the host vehicle.   The light distribution control method of the own vehicle is a polarization method, and the light distribution control means performs control to shield a region where another vehicle exists in a front region of the own vehicle. Vehicle headlight control device.   2. The light distribution control method of the own vehicle is an ADB method, and the light distribution control means performs control to increase an irradiation light intensity in a region where no other vehicle exists in a front region of the own vehicle. A vehicle headlamp control device according to claim 1. The light distribution determination means includes at least a light detection means for detecting the irradiation light of another vehicle, an image analysis means for analyzing an image obtained by imaging the other vehicle, and an inter-vehicle communication means based on information obtained by communication with the other vehicle. The vehicle headlamp control device according to any one of claims 1 to 3, wherein the vehicle headlamp control device includes one.

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