JPH09175266A - Automobile headlight optical axis control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reset an inclined headlight optical axis by one-touch switch operation while eliminating the misadjustment of the optical axis at the time of the road surface being inclined, and heighten judging accuracy at the time of a tilt angle being almost 0 deg. at a low cost so as to realize the improvement of action relatively at a low cost. SOLUTION: An automobile headlight optical axis control device is provided with an angle detector 11 outputting vs (0 deg.) when the angle θ of an optical axis to a horizontal plane is 0 deg., and a control circuit 17 started to operate by one-touch switch operation so as to drive an optical axis control actuator 15 to make the value coincident when the output signal value vs (θ) of the angle detector 11 does not coincide with vs (0 deg.) and in a range of +2 deg.--2 deg. on the basis of the angle θ=0 deg.. The judging function of the control circuit in a specified slight angle range near the angle θ=±0 is made highly sensitive, and judgment on whether vs (θ) coincides with vs (0 deg.) is made under high resolution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle which can be returned to an initial set angle (usually in a horizontal direction) by operating a one-touch switch even if a vehicle body is tilted and the direction of an optical axis of a headlight is changed in a vertical direction. The present invention relates to an improvement of a headlight optical axis control device.

[0002]

2. Description of the Related Art The direction of the optical axis of a vehicle headlamp is usually required to be substantially parallel to a horizontal plane in terms of a predetermined direction, that is, an angle in the vertical direction. Therefore, a headlight (including a reflector or a housing equipped with a headlight; the same applies hereinafter) is attached to the vehicle body side while being adjusted so that the direction of the optical axis is approximately in the horizontal direction. This is performed by an optical axis angle fine adjustment mechanism provided between the lamp and the vehicle body side (stationary portion). The headlight optical axis is properly adjusted at the time of vehicle shipping inspection by the optical axis angle fine adjustment mechanism,
Also, after shipment, corrections and adjustments will be made in a timely manner even before delivery to the user. Therefore, normally, when the vehicle is delivered to the user, the direction of the optical axis of the headlight is properly adjusted.

By the way, the angle of the automobile with respect to the road surface (horizontal plane) changes depending on the number of passengers in the automobile, the amount of luggage to be loaded, the distribution state thereof, and the like, and thus the direction of the optical axis of the headlight. Change. This means that, without knowing, you may be dazzling an oncoming vehicle with the headlight of your vehicle, or the headlight optical axis may be pointing too downward.
Therefore, the fact that the driver can appropriately correct and adjust the optical axis of the headlight is extremely useful for ensuring the safety of the own vehicle and the oncoming vehicle. Therefore, the vertical direction of the optical axis of the headlight,
For example, a change-over switch for switching between upper, middle, and lower is provided, and is normally "middle", "up" when the optical axis is directed too downward, and "down" when it is directed too upward.
In addition, a vehicle headlight optical axis control device has appeared, in which the above-mentioned changeover switch is operated to be adjusted so that the driver can perform optical axis correction adjustment.

However, in the above-mentioned conventional device, although the direction of the optical axis of the headlight is automatically adjusted almost properly only by operating the changeover switch, there are a plurality of switch buttons, and one of them is selected. Or, even if there is only one switch button, the direction of the optical axis must be selected according to the number of pressing operations. For this reason, the operation becomes troublesome, and the driver does not operate the changeover switch or operates it, but it is not uncommon to mistakenly select the upper, middle, and lower operation positions, and the original functions and effects of the device are exhibited. Can not. Therefore, in reality, the conventional device ends up being a waste of equipment, and is the basis for dazzling an oncoming vehicle with the headlight of the own vehicle without knowing it, or the headlight optical axis pointing too downward. There was a problem that it could not be an effective solution. Further, even if the operated switch button is more appropriate than the selection of other switch buttons, it is basically selected from a predetermined number, here, upper, middle, and lower three stages. As described above, the direction of the optical axis of the headlight is merely "almost" properly automatically adjusted, and it has been demanded to be more appropriately automatically adjusted.

[0005]

Therefore, the direction of the optical axis of the headlight, which changes depending on the passengers and the distribution of loaded luggage, can be returned to the initial setting angle by operating the one-touch switch. In addition, an automobile headlamp optical axis control device has been considered in which the adjustment result can be made more appropriately than the conventional device. This outputs a signal according to the angle of the optical axis of the headlight mounted on the automobile with respect to the horizontal plane, and when the optical axis is at a predetermined angle with respect to the horizontal plane, its center A gravity-dependent angle detector attached so that the angle formed by the axis and the vertical axis is approximately 0 °, a lamp actuator capable of tilting the optical axis in the vertical direction, and an operation start by operating a one-touch switch. When the value of the signal from the detector differs from the value when the angle between the central axis of the angle detector and the vertical axis is approximately 0 °, a control circuit for driving the lamp actuator so as to match them. And is provided.

However, in such a vehicle headlight optical axis control device as described above, when the road surface is largely inclined with respect to the horizontal plane, the angle detector mainly detects the inclination of the road surface with respect to the vertical axis. Since the optical axis control is performed based on the inclination of the road surface, there is a problem that the optical axis is erroneously adjusted. In particular, there is a problem that the optical axis error becomes so large that it becomes extremely dangerous when a switch is operated during traveling on a steep slope to adjust the optical axis and then the vehicle travels on a horizontal road surface.

Therefore, the control circuit does not match the value when the angle formed by the central axis of the angle detector and the vertical axis is substantially 0 °, and the positive and negative sides are set with reference to the predetermined angle. There has been considered an automotive headlamp optical axis control device in which the above-mentioned problems are solved by driving the lamp actuator so as to match them when the values are within the set constant angle range. However, in such an automotive headlight optical axis control device, the accuracy of determining whether or not the angle formed by the central axis of the angle detector and the vertical axis is substantially 0 ° is low, and external noise, etc. It is easily affected, and even if it is detected at the same angle near 0 °, it is determined to match at one time, but not at another time.
The operation was unstable and the reliability was low. At this time, in order to increase the determination accuracy, many high-precision parts have to be used, which causes a problem such as an increase in cost.

Further, when a headlight is needed (mainly at night)
Other than that, no measures were taken against the case where the operation switch was accidentally pressed (one-touch switch operation). For this reason, the optical axis is adjusted by the control circuit even if the operation switch is erroneously operated, and the optical axis is oriented in an incorrect direction when the headlight is turned on at night when the headlight is originally required. However, there is a problem that the safety is lowered. Originally, the unnecessary adjustment of the optical axis means that the mechanical drive portion of the apparatus is unnecessarily consumed, and there is a problem that the life of the drive portion is shortened.

An object of the present invention is to allow the direction of the optical axis of the headlight, which changes according to the distribution of the passengers and the load to be loaded, to be returned to the initial set angle by operating the one-touch switch. , The original function and effect of the device can be exerted, the adjustment result can be made more appropriately than the conventional device, and the optical axis is not erroneously adjusted even when the road surface is largely inclined with respect to the horizontal plane. The safety can be secured, and the accuracy of the judgment whether the angle between the central axis of the angle detector and the vertical axis is almost 0 ° can be improved at low cost, and the stability of operation can be improved. ， Reliability can be improved at low cost, and further, misalignment of the optical axis due to erroneous operation of the operation switch except when a headlight is needed is eliminated, improving safety and improving the mechanical drive part of the device. Vehicles with long life And to provide a headlight optical axis control unit.

[0010]

The above object is to output a signal according to an angle of an optical axis of a headlight mounted on an automobile with respect to a horizontal plane, and the optical axis is a predetermined value set in advance with respect to the horizontal plane. A gravity-dependent angle detector attached so that the angle formed by the central axis and the vertical axis is approximately 0 ° when the angle is 0, and a lamp actuator capable of vertically tilting the optical axis. , The value of the signal from the angle detector does not match the value when the angle formed by the central axis of the angle detector and the vertical axis is substantially 0 °, and the operation is started by operating the one-touch switch, and Headlamp optical axis control for an automobile, comprising: a control circuit for driving the lamp actuator to match values when the values are within a certain angle range set on each side of + and-on the basis of an angle. In the above arrangement, the control circuit is set to have a range of + 2 ° or less and −2 ° or more as the constant angle range, and an amplification means for amplifying the output signal of the angle detector and a value of the output signal from the amplification means are set. It is provided with two comparing means for respectively judging whether or not the value is within a predetermined small angle range around ± 0 °, or whether or not the value is within + 2 ° or less and −2 ° or more. And the amplification means is
A high amplification factor amplification unit for amplifying the angle detector output signal with a high amplification factor and a low amplification factor amplification unit for amplifying the angle detection unit output signal with a lower amplification factor, The output signal is given to the comparing means for judging whether or not the value corresponds to the value within the predetermined small angle range around ± 0 °, and the low amplification factor amplifier output signal is within the range of + 2 ° or less and -2 ° or more. Is given to the comparison means for judging whether or not the value corresponds to the above, the judgment function is made more sensitive than the ± 2 ° side within the predetermined small angle range around ± 0 °, and the angle detection is performed. This is achieved by making it possible to determine with high resolution whether or not the angle formed by the instrument center axis and the vertical axis matches the value when it is approximately 0 °.

The angle detector, which operates depending on gravity, outputs a signal corresponding to the angle (including the direction) of the optical axis of the headlight with respect to the horizontal plane, and the optical axis is preset with respect to the horizontal plane. It is attached so that the angle formed by the central axis and the vertical axis is approximately 0 ° when the predetermined angle is reached. The control circuit starts operating by one-touch switch operation, the value of the signal from the angle detector does not match the value when the angle between the central axis of the angle detector and the vertical axis is substantially 0 °, and The lamp actuator is driven in order to make them coincide with each other when the values are in the range of + 2 ° or less and -2 ° or more (+ 2 ° to -2 °) with the predetermined angle as a reference (± 0). As a result, the direction of the optical axis of the headlight, which changes depending on the passengers and the distribution of luggage to be loaded, etc., is set to the initial setting angle (usually approximately parallel to the horizontal plane (0 °)) by one-touch switch operation. Can be restored to the original function of the device,
In addition to being able to exert the effect, the adjustment result can be made more appropriately as compared with the conventional device, and even if the road surface is largely inclined with respect to the horizontal plane, erroneous optical axis adjustment is not made,
Safety is ensured.

Here, in the control circuit, the value of the signal from the angle detector is + 2.degree.
If the value is out of the range of -2 °, the value of the signal from the angle detector should match the value when the angle between the central axis of the angle detector and the vertical axis is almost 0 °. The reason why the lamp actuator is not driven is as follows. The change in the direction of the optical axis of the headlight caused by the change in the angle with respect to the road surface (horizontal plane) of the automobile due to the number of passengers in the automobile, the amount of loaded luggage, or their distribution state Studies show that the upper limit is usually 2 ° and the lower limit is 2 °, that is, + 2 ° ～
This is because it was confirmed to be within the range of -2 °. In the present invention, when the angle exceeds + 2 °, the slope is uphill,
If the angle is less than 2 °, it is judged as a downhill. In such a case, the value of the signal from the angle detector (angle detected by the angle detector) is perpendicular to the center axis of the angle detector. Even if the angle with the axis does not match the value (angle of the optical axis with respect to the horizontal plane that is set in advance) when the angle is approximately 0 °, the optical axis is not controlled. According to this, the erroneous optical axis adjustment caused by the optical axis control on the slope as described above is eliminated, and particularly when the optical axis is adjusted during traveling on a steep slope and then the road surface traveling is performed. No significant optical axis error occurs, and sufficient safety is ensured.

The control circuit further comprises an amplifying means for amplifying the angle detector output signal, and whether or not the value of the output signal from the amplifying means is a value corresponding to within a predetermined small angle range around ± 0 °, or It is provided with two comparing means for respectively judging whether or not the value is within a range of + 2 ° or less and −2 ° or more.
Further, the amplification means includes a high amplification factor amplification unit that amplifies the angle detector output signal with a high amplification factor, and a low amplification factor amplification unit that amplifies the angle detector output signal with a lower amplification factor. Become. Then, the high amplification factor amplifier output signal is set to ± 0
It is given to the comparing means for judging whether or not it is a value within a predetermined small angle range near ∘, and the low amplification factor amplifier output signal is within a range of + 2 ° or less and -2 ° or more. By giving it to the comparing means for judging whether the angle is within a predetermined small angle range around ± 0 °, the judgment function is made more sensitive as compared with the ± 2 ° side, and the central axis of the angle detector and the vertical axis are detected. The determination as to whether or not the angle formed by is equal to the value when it is approximately 0 ° is performed under high resolution. According to this, whether or not the angle formed by the central axis of the angle detector and the vertical axis coincides with the value when the angle is substantially 0 ° can be determined with high accuracy and stability. That is, the determination accuracy can be increased at low cost without using many high-precision components, and the stability and reliability of operation can be improved at low cost.

Further, the driving power is supplied to the control circuit in conjunction with the turning on / off of the headlight being turned on, and the driving power is supplied to the control circuit only when the headlight is turned on. This eliminates erroneous adjustment of the optical axis due to erroneous operation of the operation switch other than when the headlight is needed, which reduces safety and unnecessary wear of the mechanical drive part of the device, thus ensuring safety. It is possible to improve the property and prolong the life of the driving part.

The amplifying means of the control circuit comprises a high amplification factor amplifying section for amplifying the angle detector output signal with a high amplification factor and a low amplification factor amplification for amplifying the angle detector output signal with a lower amplification factor. According to the configuration with the section, the resolution is reduced to around ± 0 ° when configured with only the low amplification factor amplification section, and the output signal on the ± 2 ° side when configured with only the high amplification rate amplification section. It is possible to avoid the deterioration of reliability due to saturation of, and use only the advantages of both. Therefore, the amplification factor of the entire amplifying means can be increased to increase the sensitivity in the entire range of + 2 ° to -2 °, particularly in the vicinity of + 2 ° and -2 °.
There is no need to additionally set a slight tolerance, for example, a tolerance of ± 1 ° in the angle range of -2 °, and the resolution and accuracy of the entire apparatus are improved.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram showing an embodiment of a vehicle headlight optical axis control device according to the present invention.
Reference numeral 11 denotes a gravity-dependent angle detector such as a pendulum type, here a pendulum type angle detector, which includes a headlight (a reflector or a housing provided with a headlight, which is attached to an automobile (not shown). It refers to a reflector equipped with a headlight. The same applies hereinafter.) 12 outputs a signal according to the angle of the optical axis 13 with respect to the horizontal plane. In the pendulum type angle detector 11, the optical axis 13 is set at a predetermined angle θn preset with respect to the horizontal plane, and generally, is substantially parallel to the horizontal plane (0
The angle θ between the central axis and the vertical axis is approximately 0 ° when the angle is 0 °), and is attached to the headlight 12 via the optical axis angle fine adjustment mechanism 14. Here, the angle θ formed by the central axis of the angle detector 11 and the vertical axis is almost 0.
°, in other words, in order to easily visually judge that the optical axis 13 of the headlight is substantially parallel to the horizontal plane (0 °), for example, a level level (Fig. (Not shown) is used.

3 and 4 show the pendulum type angle detector 11 described above.
FIG. The angle detector 11 outputs a signal that changes as shown in FIG. 4 according to the angle θ (see FIG. 3) formed by the detector central axis 22 with respect to the vertical axis 21. The vertical axis in the characteristic diagram of FIG. 4, in other words, the type of the output signal may be any one of voltage (V), current (I), resistance (R), frequency (f), etc. ing. The type of output signal can be set by the circuit configuration of the angle detector 11 or the like. As can be seen from FIG. 4, when the angle θ formed by the angle detector central axis 22 and the vertical axis 21 is 0 °, a predetermined voltage, for example ± 0 V or (Vcc / 2) V, here (Vcc / 2 ) V voltage signal is output from the angle detector 11.

The optical axis angle fine adjustment mechanism 14 finely adjusts the direction of the headlamp optical axis 13, and is provided between the headlamp 12 and the vehicle body side (stationary portion). Further, the angle detector 11 is related to the movement of the optical axis angle fine adjustment mechanism 14 so that the central axis 22 is tilted in the same direction by the same angle according to the optical axis adjustment angle by the optical axis angle fine adjustment mechanism 14. Is provided. As described above, normally, the optical axis adjustment by the optical axis angle fine adjustment mechanism 14 is performed so that the optical axis 13 becomes approximately 0 ° with respect to the horizontal plane. At this time, the central axis 22 and the vertical axis of the angle detector 11 are adjusted. It is set so that the angle θ formed with 21 is approximately 0 °.

Reference numeral 15 is a lamp actuator capable of tilting the optical axis 13 in the vertical direction. The lamp actuator 15 includes only the output shaft 15a, an output shaft drive mechanism and a power source for the drive mechanism.
The position detection sensor of 5a and the like are not provided. The tilting control of the optical axis 13 in the vertical direction means the tilting control of the headlamp 12 in the vertical direction here, and is supported by the upper reflector rotating shaft 16 so as to be tiltable in the vertical direction as shown in the illustrated example. In the headlight 12 that has been turned on, by connecting the tip of the output shaft 15a of the lamp actuator 15 directed in the same direction as the optical axis 13 to the lower part of the headlight 12, the output shaft 15a of the lamp actuator 15 By the forward / backward drive, the vertical tilt control of the optical axis 13 becomes possible.

Reference numeral 17 denotes a control circuit, which is started by operating a one-touch switch and the value of the signal from the angle detector 11 indicates that the angle θ formed by the angle detector central axis 22 and the vertical axis 21 is approximately 0 °. And the optical axis 1
A value when 3 is within a range of + 2 ° or less and -2 ° or more (θn + 2 ° to θn-2 °) with reference to a predetermined angle θn preset with respect to the horizontal plane (± 0), for example, the optical axis 13 Is approximately parallel to the horizontal plane (θn = 0 °), the value is in the range of + 2 ° to -2 °.
5 is driven.

The control circuit 17 further includes an amplifying means (amplifying circuit 17a described later) for amplifying the output signal of the angle detector and a value of the output signal from the amplifying means within a predetermined small angle range around ± 0 °. Whether it is a corresponding value or less than + 2 °,-
Determine whether each value is within the range of 2 ° or more 2
It is provided with one comparison means (a comparison circuit 17b described later).
The amplifying means includes a high amplification factor amplifying unit (amplifier A2 described later) for amplifying the angle detector output signal with a high amplification factor and a low amplification factor for amplifying the angle detector output signal with a lower amplification factor. And an amplifier (amplifier A1 described later).
Then, the high amplification factor amplification section output signal is given to the comparing means for judging whether or not the value corresponds to within a predetermined small angle range around ± 0 °, and the low amplification factor amplification section output signal is equal to or less than + 2 °, By giving the comparison means for judging whether or not the value corresponds to the range of -2 ° or more, the predetermined small angle range around ± 0 ° (here, within the range of ± 0.1 °) The sensitivity of the determination function is made higher than that of the ± 2 ° side, and the determination as to whether or not the angle formed by the central axis of the angle detector and the vertical axis is substantially 0 ° is performed with high resolution. It is something that is done. An example of ± 0.1 ° as the predetermined small angle is that the resolution required in the vicinity of ± 0 ° in the vehicle headlight optical axis control device of this type is ± 0.1 ° or less. It depends.

Reference numeral 18 is an operation switch for performing the one-touch switch operation, here is a push button switch, 19 is a battery power source, and 20 is a turn-on / off switch of the headlight 12.

Here, the power switch of the control circuit 17 is
It is shared by the headlight on / off switch 20, and the driving power is supplied to the control circuit 17 in synchronism with ON (lighting operation) of the headlight on / off switch 20. The drive power is supplied to the control circuit 17 only when is turned on.

Further, the + power supply terminal of the control circuit 17 is connected to the + pole of the battery power supply 19 whose − pole is grounded through the lighting switch 20 and is connected to the non-grounded power supply terminal of the headlamp 12. They are connected via a line L1, and the drive power for the control circuit 17 is supplied by the power line L1 extending from the power terminal of the headlamp 12.

Further, in the case where the headlight is provided with a low beam bulb and a high beam bulb, and one of the bulbs is selectively supplied with power to enable selective lighting,
A low beam valve is applied as the headlight 12 in the device of the present invention, and in this case, the driving power is supplied to the control circuit 17 by interlocking with the ON / OFF switch 20 of the low beam valve 12. , The low beam valve 1
The driving power is supplied to the control circuit 17 only when 2 is turned on.

Although FIG. 1 exemplifies the case of −grounding, it may be + grounding. In this case, the polarities of the circuit elements having polarities may be reversed. Further, the connection configuration of the headlight 12, the power supply terminal of the control circuit 17, the battery power supply 19, and the headlight on / off switch 20 is also shown in FIG.
However, the driving power is supplied to the control circuit 17 in synchronism with the ON (lighting operation) of the headlight on / off switch 20 and is controlled only when the headlight 12 is turned on. Any configuration may be used as long as the driving power is supplied to the circuit 17. For example, the connection configuration as shown in FIG. 2 in which the same or corresponding parts as those in FIG.

Next, the operation of the above-mentioned device of the present invention will be described. First, the headlight optical axis 13 is previously adjusted by the optical axis angle fine adjustment mechanism 1
4 properly, here parallel to the horizontal plane (θn =
It is assumed that the angle θ formed by the central axis 22 and the vertical axis 21 of the angle detector 11 is 0 ° at this time. From this state, the angle with respect to the road surface (horizontal plane) of the car changes with the number of people riding on the car, the loading of luggage, or their distribution state,
As a result, it is assumed that the direction of the headlight optical axis 13 has changed upward (or downward). In this case, the change in the direction of the optical axis 13 is detected by the pendulum type angle detector 11. That is, the angle detector 11 detects the direction (upward or downward) and the angle with respect to the change of the direction of the optical axis 13, and outputs the voltage signal of the polarity and the value or the value, which is the value here, according to them.

The driver notices the change in the direction of the optical axis 13,
Alternatively, the push button switch 1
When 8 is pressed once, the control circuit 17 starts to operate. The control circuit 17 determines that the value of the signal from the angle detector 11 does not match the value when the angle θ formed by the angle detector central axis 22 and the vertical axis 21 is substantially 0 °, and the value is a predetermined angle. (The angle of the optical axis 13 with respect to a preset horizontal plane) θn, where the value is in the range of + 2 ° to -2 ° with 0 ° as a reference, the lamp actuator 15 is driven to match them. . That is, the control circuit 17 moves the output shaft 15a of the lamp actuator 15 forward or backward according to the value of the voltage signal from the angle detector 11. For example, if the direction of the optical axis 13 changes upward (2 ° or less),
A voltage signal corresponding to the direction and angle of the optical axis 13 is output from the angle detector 11 to control the output shaft 15a of the lamp actuator 15 to retract (move to the right in the figure). When the output shaft 15a of the lamp actuator 15 is retracted, the direction of the headlight optical axis 13 also gradually changes downward. This change is detected by the angle detector 11 at the same time, and this movement is performed by the angle detector central axis 22 and the vertical axis 2.
It continues until the angle θ with 1 becomes 0 °. At 0 °, the voltage signal from the angle detector 11 is a predetermined value, for example ± 0V or (Vcc / 2) V, here (Vcc / 2).
V, and the control circuit 17 ends its operation.
The angle θ between the central axis 22 of the angle detector and the vertical axis 21 is 0.
It means that the angle with respect to the road surface (horizontal plane) of the car changes according to the distribution state of the load on the car,
The direction of the headlight optical axis 13 is upward or downward (+ 2 ° or less,-
(2 ° or more), which means that the headlamp 12 of the vehicle unknowingly dazzles an oncoming vehicle, etc., even though it has changed upward. Is prevented and the original functions and effects of the vehicle headlight optical axis control device are exhibited. Further, the adjustment result at this time is that the control operation is continued until the angle θ formed by the central axis 22 of the angle detector and the vertical axis 21 becomes 0 °, so that it is better than the conventional apparatus that is adjusted stepwise. Become appropriate.

The value of the signal from the angle detector 11 is a value when the angle θn of the optical axis 13 with respect to a preset horizontal plane, here 0 °, is outside the range of + 2 ° to -2 °. In this case, even if the value of the signal from the angle detector 11 does not match the value when the angle θ between the angle detector central axis 22 and the vertical axis 21 is substantially 0 °, the control circuit 17 Does not work and is not optical axis controlled. That is, the value of the signal from the angle detector 11 is + 2 ° to -2.
When the value is out of the range of .degree., The control circuit 17 determines that the vehicle is currently traveling on a slope and stops the subsequent operation and does not control the optical axis. This means that when the traveling road surface is largely inclined with respect to the horizontal plane, the angle detector 11 mainly detects the inclination of the road surface with respect to the vertical axis, and the optical axis control is performed based on the inclination of the road surface. This is done in consideration of erroneous adjustment of the optical axis.

In the present invention, the range of + 2 ° to -2 ° is set as the optical axis control target range because the road surface of the automobile depends on the number of passengers in the automobile, the amount of loaded luggage, and their distribution. This is because it has been confirmed that the change in the direction of the optical axis 13 of the headlight 12 due to the change in the angle with respect to the (horizontal plane) is usually within the range of + 2 ° to −2 °. That is, it is determined that the angle is above + 2 ° and the angle is uphill, and if the angle is less than −2 °, it is downhill. In such a case, the optical axis control is not always performed. According to this, erroneous optical axis adjustment caused by optical axis control on a slope is eliminated, and in particular, a remarkable optical axis error that occurs when moving to a horizontal road surface after adjusting the optical axis while driving on a steep slope. There is no occurrence, and safety is sufficiently secured.

It is determined whether the output signal of the high amplification factor amplification section of the amplification means of the control circuit 17 has a value corresponding to a predetermined small angle range around ± 0 °, here ± 0.1 °. The low amplification factor amplifier output signal is
It is given to the comparison means for judging whether or not the value is within the range of + 2 ° to −2 °. As a result, in the predetermined small angle range (± 0.1 °) around ± 0 °, the determination function is made more sensitive than the ± 2 ° side, and the angle detector central axis 22 and the vertical axis 21 are It is determined under high resolution whether or not the angle formed by is equal to the value when the angle is 0 °. Therefore, whether or not the angle formed by the angle detector central axis 22 and the vertical axis 21 matches the value when the angle is approximately 0 ° can be determined with high accuracy and stability. That is, the determination accuracy can be improved at low cost and the operation stability and reliability can be improved at low cost without using many high-precision parts.

In the above embodiment, the angle detector 11 is
When the optical axis 13 of the headlamp 12 is substantially 0 ° (parallel) to the horizontal plane, the headlamp 12 is adjusted so that the angle θ formed by the central axis 22 and the vertical axis 21 becomes substantially 0 °. The case where the headlamp 12 is attached has been described, but when the optical axis 13 of the headlight 12 is slightly smaller or larger than 0 ° with respect to the horizontal plane, the angle θ formed by the central axis 22 and the vertical axis 21 is It may be attached to the headlight 12 so that it becomes approximately 0 °. When the angle θ is set to be substantially 0 ° when the angle is slightly smaller than 0 °, when the optical axis 13 of the headlight 12 is slightly adjusted downward, ± 0 V or (Vc
A voltage signal of c / 2) V, here (Vcc / 2) V, is output from the angle detector 11, and is attached so that the angle θ becomes approximately 0 ° when it is slightly larger than 0 °. In this case, when the optical axis 13 of the headlight 12 is slightly adjusted upward, ± 0 V or (Vcc / 2) V, in this case (V
A voltage signal of cc / 2) V is output from the angle detector 11, and the tilt control operation is performed by a one-touch switch operation with this state as a reference.
The optical axis 13 is returned to the initial setting angle, that is, a slightly downward angle or upward angle.

The above-described operation is performed by the headlight turn-off switch 20.
Is turned on (when the headlight 12 is turned on). That is, the power switch of the control circuit 17 is shared by the headlight on / off switch 20, and the supply of drive power to the control circuit 17 is linked to the ON (lighting operation) of the headlight on / off switch 20. The driving power is supplied to the control circuit 17 only when the headlight 12 is turned on. This is headlight 1
When the push button switch 18 is erroneously pressed except when 2 is required (mainly at night), if the optical axis adjustment is performed by the control circuit 17 due to this erroneous operation, the
The light axis 13 may be in an improper orientation when the headlight 12 is turned on at night when the headlight 12 is needed, which reduces safety and reduces light that is not originally necessary. The fact that the axis is adjusted means that the mechanical drive part of the device is unnecessarily consumed, and the life of the drive part is shortened. In the present invention, the driving power is supplied to the control circuit 17 only when the headlight 12 is turned on, so that the erroneous adjustment of the optical axis 13 due to the erroneous operation of the push button switch 18 other than when the headlight 12 is needed is prevented. Eliminates the risk of reduced safety and unnecessary wear of the mechanical drive part of the device, which improves safety and prolongs the life of the mechanical drive part of the device.

The drive power for the control circuit 17 is supplied by the power line L1 extending from the power terminal of the headlamp 12, and a new power source is supplied from the battery power source 19 for supplying the drive power for the control circuit 17. It is not necessary to draw out the power supply line, and the power supply is wired to the control circuit 17 simply and at low cost.

Further, when the headlight is equipped with a low beam bulb and a high beam bulb, and one of the bulbs can be selectively supplied with power to be selectively turned on, the low beam bulb can be used in the apparatus of the present invention. It is applied as the lamp 12. This is because, in the case of a headlight including the above-mentioned two bulbs, the lamp actuator for controlling the optical axis does not normally operate when the high beam bulb is lit, so that the above-mentioned optical axis adjusting operation cannot be performed, and the conventional apparatus cannot be used. This is because the lamp actuator provided in the above can not be shared as the lamp actuator 15 of the device of the present invention. Since the above-mentioned lamp actuator operates when the low beam bulb is lit, the above-mentioned optical axis adjustment operation is possible, and the lamp actuator provided in the conventional device can be used as it is as the lamp actuator 15 of the device of the present invention. Therefore, the structure is simplified and the cost is reduced.

FIG. 5 is a circuit diagram showing a concrete example of the vehicle headlamp optical axis control device according to the present invention. In FIG. 5, reference numerals 11, 12, 15, 18, 19, and 20 denote an angle detector, a headlight, a lamp actuator, a push button switch, a battery power source, and a headlight on / off switch, respectively, as in FIG. . Reference numeral 17 also shows a control circuit similar to that shown in FIG. 1. Here, an amplifier circuit 17a, a comparison circuit 17b, a logic circuit 17c, an RS flip-flop circuit 17d, a switching circuit 17e, a motor drive circuit 17f and a pull-up resistor RP5 are provided. . In this case, the amplification circuit 17a includes amplifiers A1 and A2 and resistors R1 to R14, and the comparison circuit 1
7b includes comparators COM1 to COM4, resistors R15 to R19 and pull-up resistors RP1 to RP4, a logic circuit 17c includes an AND circuit AND and OR circuits ORA and ORB, and a switching circuit 17e includes a PNP transistor Tr and a resistor R.
20 and the motor drive circuit 17f includes a relay RYA,
RYB is provided in each circuit 17a to 17f and each circuit 1
7a to 17f and pull-up resistor RP5 are connected as shown in the drawing. Reference numeral 15b is a motor for driving the output shaft of the lamp actuator 15. Also, the amplifier A2
The amplification factor of is set to 10 times or more than that of the amplifier A1. Here, the amplification factor of the amplifier A2 is 100 times,
The amplification factor of the amplifier A1 is set to 10 times.

Next, the operation of the circuit shown in FIG. 5 will be described. The output voltage of the angle detector 11 changes in proportion to the angle θ formed by the detector central axis 22 and the vertical axis 21 as described with reference to FIGS. Now, when the angle formed by the central axis 22 of the angle detector 11 and the vertical axis 21 is θ, the voltage output by the angle detector 11 is vs (θ). Further, when the angle formed by the central axis 22 of the angle detector 11 and the vertical axis 21 is θ, the amplifier A
The voltages output by 1 and A2 are Vs1 (θ) and Vs2 (θ), respectively.
And Further, the resistors R9 and R10 are set so that Va = Vs1 (0 °) and Vs2 (0 °). Vb and Vc are voltages for offsetting the output voltages Vs1 (θ) and Vs2 (θ) of the amplifiers A1 and A2 to arbitrary levels, and here, resistors R11 and R12; R13 and R14 (R11 = R12 = R13). =
It is set to (Vcc / 2) V by R14). V
A is the reference voltage to the comparator COM1, VB is the reference voltage to the comparator COM2, VA 'is the reference voltage to the comparator COM3, VB
′ Is the reference voltage to the comparator COM4, VOA is the comparator COM1
Output voltage, VOB is the output voltage of the comparator COM2, VOA '
Is the output voltage of the comparator COM3, VOB 'is the output voltage of the comparator COM4, and VON is the output voltage of the AND circuit AND.
VA ′ is vs (θ + Δθ), 0 + 2 ° = + 2 here.
The voltage corresponding to .degree., VB 'is set to vs (.theta .-. DELTA..theta.), And here the voltage corresponding to 0-2.degree. =-2.degree. Is set. Also, VA is the voltage corresponding to vs (+ 0.1 °),
VB is set to a voltage corresponding to vs (-0.1 °).

Further, in the following description, "L" means a low level voltage, "H" means a high level voltage, and the relay RY (R
ON for YA and RYB means relay coil L (LA, L
B) is energized and excited to switch and connect the movable contact c from the fixed contact a to the fixed contact b, and when it is OFF, the relay coil L (LA, LB) is not excited and the movable contact c becomes the fixed contact a. Remaining connected (state shown).

When the angle θ formed by the central axis 22 of the angle detector 11 and the vertical axis 21 is 0 ° (θn = 0 °), the output voltage vs (0 °) = (Vcc / 2 of the angle detector 11 ) V, Vs1 (θ), Vs2 (θ) with respect to the angle θ
Change (angle θ vs. output voltage Vs1 of amplifier A1, A2
(Θ), Vs2 (θ) characteristics) are shown in FIG. In FIG. 6, VL1 is the change width of Vs1 (θ) with respect to the change of the angle θ in the range of + 2 ° to -2 °, and VL2 is Vs2 (with respect to the change of the angle θ in the range of + 0.1 ° to −0.1 °. represents the change width of θ). The change in Vs2 (θ) is steeper than the change in Vs1 (θ) because the amplification factor of the amplifier A2 is 10 times or more than that of the amplifier A1. Here, the amplification factor of the amplifier A2 is set to 10 times larger (the amplification factor of the amplifier A2 is 100 times). ,
This is because the amplification factor of the amplifier A1 is set to 10 times.

Here, the reason why the amplification factor of the amplifier A2 is set higher than that of the amplifier A1 will be described. The inclination due to the load change of the car is slight (+ 0 ° as standard)
2 ° to −2 °), and therefore the angle handled there is so small that the required resolution is 0.1 ° or less. Further, since such an angle is detected by the gravity-dependent angle detector 11, the voltage output from the angle detector 11 itself is extremely small.

FIG. 7 shows the change in the output voltage Vs1 (θ) of the amplifier A1 with respect to the detected angle θ (angle θ vs. output voltage Vs1 (θ) characteristic) when only the amplifier A1 having an amplification factor of 10 is used. According to the above, the variation width VL1 of Vs1 (θ) with respect to the change of the angle θ in the range of + 2 ° to −2 ° is Vs1 (+ 2 °) to Vs1 (-2 °), which is a relatively large voltage. However, + 0.1 ° to −0.
Vs1 (θ) for changes in the angle θ in the range of 1 °
The change width VL1 'of Vs1 (+ 0.1 °) to Vs1 (-0.
1 °), which can be taken out with an extremely small voltage, and is easily affected by external noise and component accuracy. This means
Angle θ formed by the central axis 22 and the vertical axis 21 of the angle detector 11
The accuracy of the determination as to whether or not it matches the value when the angle is approximately 0 ° is low. For example, even if the same angle θ is detected in the vicinity of approximately 0 °, it is determined at some time that it matches, but there is another. This means that the operation becomes unstable, such as when it is determined that the times do not match.

Therefore, it is conceivable to use an amplifier A2 having an amplification factor of 10 times or more, for example, 100 times that of the amplifier A1 instead of the amplifier A1. The change in the output voltage Vs2 (θ) of the amplifier A2 with respect to the detected angle θ (angle θ vs. output voltage Vs2 (θ) characteristic) when only such an amplifier A2 is used is shown in FIG. In this case, as can be seen from FIG. 8, the variation width VL2 of Vs2 (θ) with respect to the variation of the angle θ in the range of + 0.1 ° to −0.1 ° is V
It becomes s2 (+ 0.1 °) to Vs2 (-0.1 °), which can be taken out as a comparatively large voltage, is less likely to be affected by external noise and component precision, and the stability of operation is increased. However, the change width VL2 ′ (not shown) of Vs2 (θ) with respect to the change of the angle θ in the range of + 2 ° to −2 ° becomes too large, and Vcc− (Vcc / 2) = (Vcc
/ 2) is exceeded, and Vs2 (θ) is saturated. For this reason, a large error occurs on the + 2 ° and -2 ° sides, the determination as to whether the detected angle θ is within the range of + 2 ° to -2 ° becomes unreliable, and proper control cannot be performed. .

In the device of the present invention, in view of the above points, the amplification factor of the amplifier A2 is 10 times or more than that of the amplifier A1. Here, the amplification factor of the amplifier A2 is 100 times and the amplification factor of the amplifier A1 is 10 times. As a result, the amplification factor of the amplifier A2 is set to 10 times that of the amplifier A1, and Vs1 (θ) has the characteristic of FIG. 7 and Vs2 (θ) has the characteristic of FIG. As shown in FIG. As a result, in the normal sensitivity determination system including the amplifier A1 and the comparators COM3 and COM4, it is determined whether or not the detection angle θ is within the range of + 2 ° to -2 ° with the normal resolution.
Further, in the high-sensitivity determination system including the amplifier A2 and the comparators COM1 and COM2, it is possible to determine with high resolution whether or not the detection angle θ is within the range of + 0.1 ° to −0.1 °. The following control operation is performed.

That is, the above Vs for VA 'and VB'
When 1 (θ) takes various values, they and VOA ', VO
The relation with B'is shown in Table 1 below.

[0045]

[Table 1]

When Vs2 (θ)> VA, VOA = "L", VOB = "H" VA> Vs2 (θ)> VB, VOA = "H", VOB = "H" VB> Vs2 At the time of (θ), VOA = “H” and VOB = “L”.

Therefore, when the transistor Tr is ON (between the emitter and the collector is conductive), Vs2 (θ)>
When VA, relay RYA is ON, relay RYB is OFF
When the motor 15b rotates in the normal direction and VA> Vs2 (θ)> VB, the relay RYA is OFF, the relay RYB is also OFF and the motor 15b is braking (stopped), and when VB> Vs2 (θ), the relay is relayed. The RYA is turned off, the relay RYB is turned on, and the motor 15b is rotated in the reverse direction. That is, the transistor T
When r is turned on, the motor 15b rotates in the normal direction, brakes (stops),
It receives the reverse control.

As described above, Vs2 with respect to VA and VB
When (θ) takes various values, they and VOA, VOB, R
The relationship between YA, RYB and the motor 15b can be summarized and shown in Table 2 below.

[0049]

[Table 2]

Regarding the OR circuit ORA, VOA ', VOB
', And if any one of the three inputs of the Q-inverted output of the flip-flop circuit 17d is "H", the output voltage VRA becomes "H" and the transistor Tr is not turned on. Then, the output voltage VRA is all "L" and the transistor Tr is turned on.

Regarding the OR circuit ORB, VOA 'and VOB
If any one of the three inputs of ‘′ and VON is“ H ”, the output voltage VRB becomes“ H ”, the flip-flop circuit 17d is reset, and the Q inversion output becomes“ H ”, otherwise. Under the input condition of, the output voltage VRB is all "L", and the Q inverted output of the flip-flop circuit 17d is in the output content holding state.

The operation of the entire circuit shown in FIG. 5 under the above operating conditions of the control circuit 17 will be described below with reference to FIGS. 1 and 3. Now, the automobile is on a horizontal road surface, and the angle of the automobile with respect to the road surface (horizontal plane) changes according to the distribution state of people's riding on the automobile and the loading of luggage, and the direction of the headlight optical axis 13 is changed accordingly. If it changes upward or downward, the headlight (reflector) 1
The pendulum type angle detector 11 mounted on the optical axis angle fine adjustment mechanism 14 is tilted to detect a change in the direction of the optical axis 13. As a result, Vs2 (θ)> VA or VB> V
s2 (θ), and one of the relays RYA and RYB is turned on.

When the push button switch 18 is pressed once in this state, the Q inversion output of the flip-flop circuit 17d becomes "L", the transistor Tr is turned on, and the relay R
The motor 15b rotates in the direction determined by which of YA and RYB is ON. As a result, the output shaft 15a of the lamp actuator 15 rotates around the axis and moves forward or backward, and the headlight 12, in other words, the optical axis 13 is tilted upward or downward about the reflector rotation shaft 16.
When the headlight 12 is tilted upward or downward, the angle detector 1
The inclination of 1 is also returned to the initial setting angle (the angle θ formed by the central axis 22 and the vertical axis 21 is 0 °). The above operation is performed until the angle detector 11 returns to the initial set angle, that is, VA> Vs2.
It continues until (0 °)> VB, and when VA> Vs2 (0 °)> VB, the motor 15b stops (becomes in a braking state). As a result, the angle of the vehicle with respect to the road surface (horizontal plane) changes according to the distribution state of the load on the vehicle, and the direction of the headlight optical axis 13 changes upward or downward. Is automatically corrected to the proper direction, here the horizontal direction.

At this time, the vehicle is not on a horizontal road surface,
If it is on a road surface inclined by θ, the central axis of the angle detector 11 forms (θ + Δθ) with respect to the vertical axis. Therefore, the output voltage of the angle detector 11 is vs (θ + Δθ), and the output voltage of the amplifier A1 is Vs2 (θ + Δθ). Δθ above
When becomes larger, the angle detector 11 mainly detects the inclination of the road surface with respect to the vertical axis as described above, and the optical axis is erroneously adjusted.

Therefore, the optical axis control target angle area is set to θ + Δθ ≧ θ ≧ θ−Δθ, and the transistor Tr is turned off outside the optical axis control target angle area so that the motor 15b is stopped. By doing so, it is possible to avoid erroneous optical axis adjustment. Control circuit 17 shown in FIG.
In the comparison circuit 17b, the optical axis control target angle region θ + Δθ ≧ θ ≧ θ−Δθ is set to VA ′ = Vs2 (θ + Δ
θ), VB ′ = Vs2 (θ−Δθ), and the transistor Tr is set outside this angle range of the optical axis control.
Is turned off and the motor 15b is stopped to avoid erroneous optical axis adjustment. Further, in the present invention, (θ + Δθ) at this time is set to + 2 °, (θ-Δθ) is set to −2 °, and VA ′ is set to + 2 ° and VB ′ is set to −2 °. The optical axis automatic correction described above is performed only within this range, and the practically appropriate optical axis is maintained.

Here, the output voltage Vs2 (θ) of the amplifier A2 of the control circuit 17 (high amplification factor amplifier output signal) is ± 0.
A comparator COM that determines whether or not the value is within a predetermined small angle range (here, within ± 0.1 °).
1 and COM2, and the output voltage Vs1 of the amplifier A1
A comparator COM that determines whether or not (θ) (low amplification factor output signal) has a value corresponding to a range of + 2 ° to −2 °.
3, given to COM4. As a result, in the range of a slight angle (± 0.1 °) in the vicinity of ± 0 °, the judgment function has a higher sensitivity compared to the ± 2 ° side, and the angle formed by the angle detector central axis 22 and the vertical axis 21. It is determined under high resolution whether or not is equal to the value when is almost 0 °. Therefore, the angle formed by the angle detector central axis 22 and the vertical axis 21 is almost zero.
The determination as to whether or not the value coincides with the value at the time of is performed with high accuracy and stability. That is, the determination accuracy can be improved at low cost without using many high-precision parts, and the stability and reliability of operation can be improved at low cost.

The above operation is performed only when the headlight on / off switch 20 is ON (when the headlight 12 is lit) as described above. This eliminates erroneous adjustment of the optical axis 13 (see FIG. 1) due to an erroneous operation of the push button switch 18 except when the headlight 12 is needed, resulting in a reduction in safety and a mechanical drive portion of the device. The necessary wear is eliminated, the safety is improved, and the life of the driving part is extended.

The amplifying means of the control circuit 17 (amplifier A
1 and A2), the angle detector output vs (θ) is amplified with a high amplification factor (amplifier A2) and the angle detector output vs (θ) is amplified with a higher amplification factor. According to the configuration with the low amplification factor amplification unit (amplifier A1), the resolution is reduced to around ± 0 ° and the high amplification factor amplification unit (amplifier) is configured only with the low amplification factor amplification unit (amplifier A1). It is possible to avoid deterioration of reliability due to saturation of the output signal on the ± 2 ° side in the case of configuring only A2), and it is possible to use only the advantages of both. Therefore, the amplification factor of the entire amplifying means (amplifiers A1 and A2) can be increased to enhance the sensitivity in the entire range of + 2 ° to -2 °, particularly around + 2 ° and -2 °.
It is not necessary to additionally set a slight tolerance, for example, a tolerance of ± 1 ° in the angle range of 2 ° to -2 °, and the resolution and accuracy of the entire apparatus can be improved.

In the embodiment shown in FIG. 5, the case where two detector output voltage amplified signals having different amplification factors are taken out from the output terminals of two amplifiers A1 and A2 having different amplification factors connected in parallel has been described. From the output end of the n-th stage amplifier and the output end of the (n + n) th stage amplifier of a plurality of amplifiers connected in series, for example, the output end of the first stage amplifier of two amplifiers each having an amplification factor of 10 times. And the second stage (final stage)
You may make it take out from each output terminal of an amplifier. Alternatively, the amplifiers may be taken out from two amplifier output terminals of a plurality of amplifiers connected in series and in parallel.

[0060]

As described above, according to the present invention, the direction of the optical axis of the headlight, which changes depending on the number of passengers, the amount of luggage to be loaded or the distribution state thereof, can be changed by a one-touch switch operation. It can be returned to the initial setting angle, usually almost parallel (0 °) to the horizontal plane. Therefore, the original function and effect of the device (unknowingly dazzling an oncoming vehicle with the headlight of the own vehicle, , The function and effect of solving the problem that the optical axis of the headlight is directed too downward, etc. can be exhibited, and the adjustment result can be made more appropriately than the conventional device, and the road surface is larger than the horizontal plane. Even if it is tilted, there is an effect that the optical axis is not erroneously adjusted and safety can be secured.

Furthermore, since the driving power is supplied to the control circuit only when the headlight is turned on, there is no erroneous adjustment of the optical axis due to an erroneous operation of the operation switch except when the headlight is needed, and safety is ensured. Also, there is an effect that it is possible to improve the property and prolong the service life of the mechanical driving part of the device.

Since the drive power of the control circuit is supplied by the power line extending from the power terminal of the headlight, it is necessary to draw a new power line from the battery power source for supplying the drive power of the control circuit. There is no advantage, and there is an advantage that the power supply wiring to the control circuit can be performed easily and at low cost.

The amplifying means includes a high amplification factor amplifying section for amplifying the angle detector output signal with a high amplification factor and a low amplification factor amplifying section for amplifying the angle detector output signal with a lower amplification factor. It is equipped with a higher sensitivity judgment function than the ± 2 ° side within a predetermined small angle range around ± 0 °, and the angle between the central axis of the angle detector and the vertical axis is almost 0 °. The determination as to whether or not it matches the value at this time is performed under high resolution. Therefore, it is possible to improve the determination accuracy of whether or not the angle formed by the central axis of the angle detector and the vertical axis is substantially 0 ° at a low cost, and to improve the stability and reliability of the operation at a low cost. There is also an advantage that it can be improved by.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of a device of the present invention.

FIG. 2 is a configuration diagram showing a main part of another embodiment of the device of the present invention.

FIG. 3 is an explanatory diagram of a pendulum type angle detector in FIG.

FIG. 4 is a graph showing changes in a detector output signal with respect to an angle θ formed by a central axis and a vertical axis of the pendulum type angle detector in FIG.

FIG. 5 is a circuit diagram showing a specific example of the device of the present invention.

6 is an angle θ formed between the central axis and the vertical axis of the angle detector in FIG. 5 and output voltages Vs1 (θ) and Vs2 of amplifiers A1 and A2.
It is a graph which shows the relationship with ((theta)).

FIG. 7 is a graph for explaining the characteristics of the output voltage Vs1 (θ) of the amplifier A1 in FIG.

FIG. 8 is a graph for explaining the characteristic of the amplifier A2 output voltage Vs2 (θ) in FIG.

[Explanation of symbols]

11 ... Pendulum type angle detector, 12 ... Headlight, 13 ... Optical axis, 14 ... Optical axis angle fine adjustment mechanism, 15 ... Lamp actuator, 15a ... Lamp actuator output shaft, 16 ...
Reflector rotating shaft, 17 ... Control circuit, 18 ... Push button switch, 19 ... Battery power supply, 20 ... Headlight on / off switch, L1 ... Power line, 15b ... Lamp actuator output shaft drive motor, 17a ... Amplifying circuit, 17b ... Comparator circuit, 17c ... Logic circuit, 17d ... RS flip-flop circuit, 17e ... Switching circuit, 17f ... Motor drive circuit, A1, A2 ... Amplifier, R1 to R20 ... Resistor, CO
M1 to COM4 ... comparator, RP1 to RP5 ... pull-up resistor,
AND ... AND circuit, ORA, ORB ... OR circuit, Tr ...
PNP transistor, RYA, RYB ... Relay.

Claims (3)

[Claims] 1. A signal that outputs a signal according to an angle of an optical axis of a headlight mounted on an automobile with respect to a horizontal plane, when the optical axis is at a predetermined angle with respect to the horizontal plane. The angle between the central axis and the vertical axis is almost 0
A gravity-dependent angle detector mounted so that
A lamp actuator capable of tilting the optical axis in the vertical direction and a signal value from the angle detector which is activated by one-touch switch operation, and the angle between the central axis of the angle detector and the vertical axis is approximately 0 °. Does not match the value when
And a control circuit for driving the lamp actuator so as to make the values coincide with each other when the values are within a certain angle range set on each side of + and − with reference to the predetermined angle. In the headlight optical axis control device, the control circuit has a fixed angle range of + 2 ° or less,
A range of -2 ° or more is set, and whether the value of the output signal from the amplification means for amplifying the output signal of the angle detector corresponds to within a predetermined small angle range around ± 0 °. Or two comparing means for respectively judging whether or not the value is within a range of + 2 ° or less and -2 ° or more, the amplifying means comprising the angle detector output signal having a high amplification factor. And a low amplification factor amplification unit that amplifies the angle detector output signal with a lower amplification factor, and outputs the high amplification factor amplification unit output signal to a predetermined value near ± 0 °. Is given to the comparing means for judging whether or not the value corresponds to within the small angle range of, and the output signal of the low amplification factor amplification section is + 2 ° or less, −
By giving the comparison means for judging whether or not the value corresponds to the range of 2 ° or more, the judgment function is highly sensitive in the predetermined small angle range around ± 0 ° as compared with the ± 2 ° side. Headlamp light for an automobile, characterized in that it is determined with high resolution whether or not the angle formed by the central axis of the angle detector and the vertical axis matches the value when the angle is substantially 0 °. Axis control device. 2. The drive power supply to the control circuit is performed in conjunction with the ON / OFF switch of the headlight being turned on, and the drive power supply to the control circuit is supplied only when the headlight is turned on. The vehicle headlamp optical axis control device according to claim 1, wherein: 3. The vehicle headlamp optical axis control according to claim 1, wherein the drive power of the control circuit is supplied by a power line extending from a power terminal of the headlamp. apparatus.