JPH01153354A - Illuminating angle adjusting device for vehicle head lamp - Google Patents

Abstract

PURPOSE:To reduce the number of connecting wires by producing an output signal in accordance with a difference between a set voltage which is set depending upon a take-out position of partial voltage and a reference voltage which is taken out from a reference resistance means applied with a power source voltage so as to change the illuminating angle. CONSTITUTION:The partial voltage of a set voltage take-out resistance 41 applied at its both ends with the voltage of a power source 3 is changed over by means of a manipulating means 42 in a set voltage take-out circuit 4 so as to extract a set voltage which is delivered to a reference comparing circuit 52. Comparators CP1 through CP4 compares the set voltage with reference voltages which are partial voltages V1 through V4 taken out from a reference voltage setting resistor 51, and an output signal generating circuit 53 produces an output signal so that an illuminating angle changing circuit 54 drives a d.c. motor 46 in a normal or reverse direction in order to obtain an illuminating angle corresponding to the set voltage. In this arrangement the number of connecting lines led out from the set voltage take-out circuit 4 on the passenger compartment side is only three, that is, only wires La, Lb, Lc are led out. Thus it is possible to reduce entrance of noise through a wire through-hole, and to facilitate the water-proof measure.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a method for adjusting the irradiation angle of a headlamp, which is tiltably held with respect to a vehicle body, in multiple stages by remote control from the driver's seat side. The present invention relates to a vehicular headlamp illumination angle adjustment device suitable for use.

[Conventional technology]

In vehicles, especially automobiles, the body and axle are connected by temporary springs,
Since the vehicle is connected by a suspension system made of coil springs, if a large load is applied to the front or rear wheels of the vehicle, the vehicle will sink forward or backward, causing the headlights to sag. Not only does the angle of illumination in the vertical direction relative to the road surface change, impairing driving safety, but if the headlights tilt upwards due to the vehicle moving backwards, there is a risk of causing significant dazzle to the driver of an oncoming vehicle.

In order to correct this change in the illumination angle of the headlights relative to the road surface, the headlights are held tiltable relative to the vehicle body, and the illumination angle of the headlights can be controlled remotely from the driver's seat. A device configured to be able to be adjusted by
This is disclosed in Japanese Patent No. 46733. FIG. 5 is a diagram showing the operating principle of the irradiation angle adjustment device disclosed in this Japanese Patent Application Laid-Open No. 61-46733. The aim is to adjust the illumination angle of a headlamp (not shown) that is tiltably held relative to the vehicle.

That is, by switching the connection mode of the operation switch 1 from the illustrated state, for example, the common terminal 1-.

When the switching terminal 1-6 is connected, a current flows through the relay coil RLI of the drive unit 2 through the path of the sliding contact 21d, the conductor pattern 22, and the sliding contact 21a. Common terminal r11c of normally closed contact rj21 and its normally open contact terminal rI! 1a becomes electrically conductive. Common terminal r of this normally open/normally closed contact rj21
Due to the conduction between flc and its normally open contact terminal rβ1a, a current flows in the direction A in the figure to the DC motor 24, and the motor 2
4 rotates forward to rotate the lamp drive shaft 25 to the right in the figure.

By this clockwise rotation of the lamp drive shaft 25, the irradiation angle of the headlight moves upward and the conductor patterns 22 and 2
3 formed on its upper surface rotates clockwise,
The sliding contact 21d is separated from the conductor pattern 22, the energization of the relay coil RLI is released, and the common terminal rj! of the normally open/normally closed contact rll is released. lc and normally open contact terminal rβ
1a becomes non-conductive, power supply to the DC motor 24 is cut off, and the irradiation angle of the headlight is fixed at a predetermined position in the upward direction.

When the connection mode of the operation switch 1 is switched from this state to the original state, that is, when the common terminal l-0 and the switching terminal 1-4 are brought into the connected state, the relay coil RL2 of the drive unit 2 is ml>A current flows through the path of contact 21e-conductor pattern 23-sliding contact 21i, and the common terminal rj22c of the normally open/normally closed contact r12 of this relay coil RL2 and the normally open contact terminal r12a become conductive. A current flows through the DC motor 24 in the direction B shown in the figure, causing the motor 24 to rotate in the reverse direction, causing the lamp drive shaft 25 to rotate to the left, thereby moving the irradiation angle of the headlight downward.

That is, as can be seen from the above description, by switching the connection mode of the operation switch 1 to the switching terminals 1-1 to 1=7, it is possible to remotely adjust the irradiation angle in seven steps in the vertical direction.

[Problem that the invention seeks to solve]

However, with such a conventional vehicle headlamp illumination angle adjustment device, there is a problem in that as the number of illumination angle adjustment stages increases, the number of connection lines between the operation switch and the drive unit increases.

That is, in the case of the irradiation angle adjustment device shown in FIG.
In order to adjust the illumination angle of the stages, seven connection lines L1 to L7 are required between the operation switch 1 and the drive unit 2, and the drive unit 2 is attached to the headlight and placed at the front of the vehicle. Therefore, large holes (wiring holes) through which the connection lines L1 to L7 pass must be made in the partition between the engine room (outside the vehicle) and the driver's seat side (inside the vehicle).

In other words, as the number of connection lines between the operation switch and the drive unit increases, the wiring holes created in the partition section become larger, which increases the noise in the engine room that is led into the car through these wiring holes. A problem will arise.

In addition, by increasing the number of connection lines between the operation switch and the drive unit, waterproofing measures (for example, connecting lines It was extremely troublesome to pass each wire through a small-diameter bushing hole drilled in a large-diameter bushing, and it was also difficult to route the wires.

[Means for solving problems]

The present invention has been made in view of these problems, and it is possible to set a divided voltage of a different value by switching the extraction position of the divided voltage with respect to a resistor means formed by applying a power supply voltage to both ends of the resistor means. Along with taking it out as
A divided voltage taken out from a reference resistance means formed by applying a power supply voltage to both ends of the voltage is set as a reference voltage, and this reference voltage and the set voltage are compared, and the reference voltage and the set voltage are compared. An output signal corresponding to the comparison result is generated based on the comparison result, and the irradiation angle of the headlight on the vehicle is varied to a position determined according to the generated output signal.

[Effect]

Therefore, according to the present invention, by arranging the resistance means inside the vehicle and directing the set voltage taken out from the resistance means to the outside of the vehicle, the number of connection lines drawn into the interior of the vehicle can be reduced at least to both ends of the resistance means. It is possible to use three lines in total, including the power supply voltage line to be applied and the line for deriving the set voltage.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The irradiation angle adjustment device for a vehicle headlamp according to the present invention will be described in detail below. FIG. 1 is a circuit diagram showing an embodiment of this irradiation angle adjusting device. In the figure, 4 is a set voltage extraction circuit arranged on the driver's seat side, and 5 is a drive unit attached to a headlamp (not shown) that is tiltably held with respect to the vehicle body.

The set voltage take-out circuit 4 includes a set voltage take-out resistor 41 formed by connecting resistors R1 to R4 in series, and a rotary operation switch 42.
The power supply voltage (DC 12V) of the vehicle-mounted battery 3 is applied to both ends of the in-vehicle battery 3. That is, one end of the set voltage extraction resistor 41 is connected to the positive polarity side of the vehicle battery 3 via its power input terminal 4a, and the other end is body grounded within the set voltage extraction circuit 4. The connection point between the resistor R1 and the power input terminal 4a, the connection point between the resistor R1 and the resistor R2, and the connection point between the resistor R2 and the resistor R3.

A switching terminal 42-1+42 of the operation switch 42 is connected to the connection point between the resistor R3 and the resistor R4 and the ground connection point of the resistor R4.
-2.42-: 1.42-a and 42-5 are connected, and the common terminal 42-0 of the operation switch 42 is connected to the signal input terminal 5 of the drive unit 5 via its output terminal 4b.
connected to b. The resistance values of the resistors R1 to R4 in the set voltage extraction resistor 41 are set to be equal (
R1=R2=R3=R4=RΩ), therefore, the switching terminals 42-1.42-2.42-x of the operation switch 42,
42-4 and 42-6 have 12 V, 9 V, 6 V, and 3 as the divided voltages of the set voltage extraction resistor 41.
DC voltages V and OV are generated.

On the other hand, the drive unit 5 includes a reference voltage setting resistor 51 formed by connecting resistors R5 to R9 in series, and a comparator CPI.
- A voltage comparison circuit 52 consisting of CP4, an output signal generation circuit 53 consisting of EX-OR circuits (hereinafter abbreviated as EX) 531 to 534 and a transistor array (T, array) 535, and generation of this output signal generation circuit 53. It is composed of a variable illumination angle circuit 54 that varies the illumination angle of the headlight to a position determined according to an output signal, and a fail-safe circuit 55. is being applied. That is,
One end of the reference voltage setting resistor 51 is connected to the positive polarity side of the on-vehicle battery 3 via its power input terminal 5a, and the other end is body grounded within the drive unit 5.

Then, a divided voltage V1. V2. V3 and v4 are used as reference voltages by comparators CP1. CP2.
It is set to the inverting input terminals of CP3 and CF2. Comparator CP 1. CF2. The divided voltage taken out from the common terminal 42-0 of the operation switch 42 in the setting voltage extraction circuit 4 is input as the setting voltage VIN to the non-inverting input terminals of CF2 and CF2 via the fail-safe circuit 55. It has become. The fail-safe circuit 55 includes a protective resistor RIO connected between the non-inverting input terminals of the comparators CPI to CP4 and the signal input terminal 5b of the drive unit 5, and a connection between this resistor RIO and the non-inverting input terminals of the comparators CPI to CP4. It consists of a parallel circuit of capacitor C and resistor R11 connected between the point It is set large.

Furthermore, the resistors R5 to R9 in the reference voltage setting resistor 51 are set so that the resistors R6, R7, and R8 are set equal to the resistors R1 to R4 in the setting voltage extraction resistor 41 (R6=
R7=R8=RΩ), and resistor R5 and resistor R9 are set to 1/2 of the resistance value of these resistors R6 to R8 (R
5=R9=R/2Ω). Therefore, comparator CP
1. CP2, CP3. The reference voltages set at the inverting input terminal of CP4 are V 1 =10.5V, V 2 =7.
5V, V 3 =4.5V.

V4=1.5V.

Then, the comparator CPI in the voltage comparison circuit 52
The output is input to one end of the EX 531 as a signal (d) and to the transistor array 535 as a signal (i). Also, comparator CP
The output of 2 is sent as a signal (C) to the other end of EX531 and E
At one end of X532, the output of comparator CP3 is connected to the signal (
b) The output of comparator CP4 is connected to the other end of EX532 and one end of EX533 as a signal (al as EX5
33 and one end of EX534, and a signal at the rHJ level is always input to the other end of EX534 via a pull-up resistor R1'l. And EX531.532.
The outputs of 533 and 534 are the signals (h), (f
1 and (e) are manually input to the transistor array 535, and when only the signal (e) among the input signals reaches the rHJ level, the transistor array 535 outputs only its output terminal 535a. rLJ level.

In addition, when only the input signal (f) becomes the rHJ level, only the output terminal 535b is set to the "L" level, and in the same manner, when only the signal (g) becomes the rHJ level. outputs only the output terminal 535C, and the signal (h
When only l reaches rHJ level, output terminal 535
When only the signal (i) reaches the "H" level, only the output terminal 535e becomes the rLJ level.

The output terminal 53 of this transistor array 535
5a to 535e are sliding contacts 544b to 54 in the variable irradiation angle circuit 54, which are in sliding contact with the semicircular band-shaped conductor patterns 542 and 543 formed on the sliding substrate 541.
4f, and the potential level developed at sliding contacts 544a and 544g is connected to input terminals 545a and 545.
It is inputted to the forward/reverse rotation motor driver 545 via b. Then, this forward/reverse motor driver 5
45 through its input terminals 545a and 545b.
When LJ and rHJ level signals are input, a drive current flows in the direction A shown in the figure to the DC motor 546 via the forward/reverse motor driver 545, and this drive current causes the DC motor 546 to rotate in the forward direction, thereby driving the headlight. As the irradiation angle moves upward, the sliding substrate 541 rotates to the right in the figure. In addition, the forward/reverse motor driver 5
45 through its input terminals 545a and 545b.
When HJ and rLJ level signals are input, a current flows in the direction B shown in the figure to the DC motor 546 via the forward/reverse motor driver 545, the DC motor 546 rotates in the reverse direction, and the illumination angle of the headlight is directed downward. As you move in the direction,
The sliding substrate 541 rotates to the left in the figure.

Note that the sliding contact 544a in the variable irradiation angle circuit 54
and 544g are pull-up resistors Rpz and RP3
connected to a high potential power supply via.

Furthermore, the body ground in the set voltage outlet path 4 and the body ground in the drive unit 5 (reference voltage setting resistor 5
1) are mutually connected via the ground terminal 4C of the set voltage extraction circuit 4 and the ground terminal 5c of the drive unit 5.

Next, the operation of the irradiation angle adjusting device configured as described above will be explained. That is, it is now assumed that the connection mode of the operating switch 42 in the set voltage outlet path 4 is in the state shown in the figure, that is, the common terminal 42-0 and the switching terminal 42-3 are in the connected state.

In this case, the divided voltage taken out from the set voltage take-out resistor 41 via the common terminal 42-0 is 6■, and this 6
The divided voltage (2) appears at the connection point between the resistor RIO of the fail-safe circuit 55 and the capacitor C in the drive unit 5, and this divided voltage is set as the set voltage VIN at the non-inverting input terminal of the comparator CPI-CP4 (7). be done. This 6v setting voltage VIN causes the comparator CP1.
CP 2. CP 3゜The output level of CP4 is rLJ,
rLJ, rHJ, rH", and only the output level of EX532 becomes rHJ. Therefore, only the output terminal 535c of the transistor array 535 becomes the rLJ level, and in the illustrated state, the input terminals 545a and 545. Since the input signal levels of b are both rHJ, no drive current is supplied to the DC motor 546 via the forward/reverse motor driver 545, and the irradiation angle of the headlight is set in a predetermined direction determined by the rotational angular position of this motor 546. Maintain a stopped state facing the direction. In this embodiment, the irradiation angle at this time is the center position in the vertical direction with respect to the road surface.

In such a state, if the connection mode of the operation switch 42 in the set voltage outlet path 4 is switched and, for example, the common terminal 42-0 and the switching terminal 42-2 are connected, the common terminal 42-0 will be connected. The divided voltage taken out from the setting voltage take-out resistor 41 through the
The divided voltage (2) appears at the connection point between the resistor RIO of the fail-safe circuit 55 and the capacitor C in the drive unit 5, and this divided voltage is set as the set voltage v1.4 at the non-inverting input terminals of the comparators CP1 to CP4. be done. Due to this 9■ setting voltage■, the comparator CP 1゜CF
2. CF2. The output level of CF2 is rLJ, rHJ
, rHJ, rHJ, and only the output level of EX531 becomes "I". Therefore, only the output terminal 535d of the transistor array 535 is at rLJ level,
The input signal levels of the input terminals 545a and 545b of the forward/reverse rotation motor driver 545 become rLJ and rHJ, and a drive current flows in the A direction to the DC motor 546 via the forward/reverse rotation motor driver 545.
As G rotates forward, the irradiation angle of the headlight begins to move upward. On the other hand, as the DC motor 546 rotates forward, the sliding board 541 rotates clockwise, and the sliding contact 5 connected to the output terminal 535d of the transistor array 535
44e separates from the conductor pattern 543, the input signal level to the input terminal 545a of the forward/reverse rotation motor driver 545 becomes "H". That is, the input signal levels of the input terminals 545a and 545b of the forward/reverse motor driver 545 both become rHJ, and the supply of drive current to the DC motor 546 in the A direction via the forward/reverse motor driver 545 is cut off. This DC motor 54
By stopping the motor by cutting off the supply of drive current to 6, the irradiation angle of the headlight is fixed at a predetermined position in the upward direction.

In addition, the connection mode of the operation switch 42 in the set voltage extraction circuit 4 can be switched, for example, the common terminal 42-
0 and its switching terminal 42-4 are connected, the divided voltage taken out from the setting voltage extraction resistor 41 through the common terminal 42-0 becomes 3■, and this 3■ divided voltage is the one that is connected to the drive unit. 5, the fail-safe circuit 5
5 appears at the connection point between resistor RIO and capacitor C, and this divided voltage is applied to comparator CPI~ as set voltage VIN.
Set to the non-inverting input terminal of CP4. The comparator CP1. CF2. CF2
．． The output level of CF2 is rLj, rLJ, rLJ
.

rHJ, and only the output level of EX533 becomes "H". Therefore, only the output terminal 535b of the transistor array 535 becomes the rLJ level, and the input signal levels of the input terminals 545a and 545b of the forward/reverse motor driver 545 become rHJ and rLJ. A drive current flows in direction B, causing the motor to rotate in reverse, and the illumination angle of the headlight begins to move downward. On the other hand, as the DC motor 546 rotates in the opposite direction, the sliding board 541 rotates to the left.
When the sliding contact 544c connected to the output terminal 535b of the transistor array 535 separates from the four-body pattern 542, the input terminal 5 of the forward/reverse motor driver 545
The signal level to 45b becomes rHJ. That is, the input terminals 545a and 54 of the forward/reverse motor driver 545
Both the input signal levels of 5b become rHJ, the DC motor 546 stops, and the irradiation angle of the headlight is fixed at a predetermined position in the downward direction.

The table shown below (Table 1) is a truth table showing the level change of the signal (al~(1)) with respect to the connection mode of the operation switch 42 in this irradiation angle adjustment device. 1 to ■ are the common terminals 42-8 and switching terminals 42-2 to 42 in the operation switch 42.
2-s is shown.

Table 1 As can be seen from this truth table, operation switch 4
By appropriately switching the connection mode No. 2, the rHJ level positions of the signals (e) to (1) input to the transistor array 535 change according to the connection mode, and the rHJ level position of the signals (e) to (1) input to the transistor array 535 changes. el~
The irradiation angle of the headlight is moved and fixed at a position determined according to the rHJ level position in (i).

As described above, according to the irradiation angle adjustment device according to this embodiment,
Three connection lines La% connect the set voltage outlet path 4 located on the driver's seat side and the drive unit 5 attached to the headlight.
Since it is possible to adjust the irradiation angle by connecting with L C, it is possible to make the wiring hole in the partition between the engine room and the driver's seat side smaller, and it is possible to make the wiring hole in the compartment between the engine room and the driver's seat side smaller. This makes it possible to suppress noise in the engine room. Furthermore, since the number of connection lines is small, it is easy to take waterproof measures against rainwater etc. that are led into the inside of the vehicle through the connection lines from the headlights arranged outside the vehicle, and the wiring work is also easy. In this embodiment, the ground terminal 4C of the set voltage extraction circuit 4 and the ground terminal 5C of the drive unit 5 are connected by the connection line Lc. Drive unit 5
This is not necessarily necessary since the body is individually grounded in each case. If the connection line Lc is omitted, the number of connection lines drawn into the inside of the vehicle can be further reduced to two, but if the body ground is taken alone, the ground potential will differ depending on where the body ground is taken. From this point of view, it is desirable that the ground line of the set voltage extraction circuit 4 and the ground line of the drive unit 5 be connected to each other via the connection line Lc.

Furthermore, in this embodiment, since the set voltage VIN to the voltage comparison circuit 52 is set via the fail-safe circuit 55, when switching the connection mode of the operation switch 42 in the set voltage output path 4, Even if the extraction of the divided voltage from the set voltage extraction resistor 41 is momentarily interrupted, the value of the set voltage VIN to the voltage comparator circuit 52 remains approximately the same as that before switching due to the charging of the capacitor C in the fail-safe circuit 55. It is possible to always obtain stable irradiation angle switching operation. In addition, if the input of the divided voltage from the set voltage take-out resistor 41 to the drive unit 5 is interrupted for a long time due to a disconnection of the connection line Lb, etc., the charge of the capacitor C in the fail-safe circuit 55 is gradually discharged through the resistor R11, the value of the set voltage VIN to the voltage comparator circuit 52 becomes zero, and the irradiation angle of the headlight is set to the maximum downward direction position according to the connection mode (■) of the operation switch 42. gradually moves and becomes fixed. Therefore, even if a disconnection accident occurs in the connection line Lb while the illumination angle of the headlight is adjusted upward, a predetermined time period determined by the discharge time constant of the capacitor C and the resistor R11 in the fail-safe circuit 55 will elapse. After that, the irradiation angle of the headlight always moves downward and remains fixed, and there is no danger of dazzling the driver of an oncoming vehicle.

Further, in this embodiment, the signals (a) to +d> sent out by the voltage comparison circuit 52 are processed by the EX531 to EX534 and inputted to the transistor array 535, but the hexadecimal decoder 5
Signals (a) ~ sent out by the voltage comparator circuit 52 using 36
(d) may also be processed. The table shown below (Table 2) is a truth table showing changes in the input/output signals of the binary-hexadecimal decoder 536 with respect to the connection mode of the operation switch 42.

Furthermore, in the voltage comparator circuit 52 shown in FIG. 2, if the terminal positions of the non-inverting input terminal and the inverting input terminal of the comparators CP2 and CP3 are swapped (see FIG. 3), the signal sent out by the voltage comparator circuit 52 can be changed. (al~(dl) changes as shown in the table below (Table 3) depending on the connection mode of the operation switch 42, and as shown in FIG. It becomes possible,
The package structure of the binary-hexadecimal decoder 536 can be made smaller.

Table 3 Also, as shown in FIG. 4, the voltage comparison circuit 52 is constituted by open collector type comparators CP1a to CP4a, and pull-up resistors RPa to RP? are connected between the outputs of the comparators CP1a to CP4a and the high potential power supply. If the outputs of the comparators CPLa to CP4a are connected to the open collector type inverters INVI to INV4 and the wiring shown in the diagram is made to the transistor array 535, the following will be established for the connection mode of the operation switch 42. The truth table shown in the table (Table 4) is obtained.

With this configuration, the 12V DC power supply can be used directly in the output signal generation circuit 53, and the decoder 536 shown in FIGS. 2 and 3 can be used directly.
Furthermore, compared to an output signal generation circuit using the decoder 537, the output signal generation circuit can have a higher withstand voltage (the decoder generally uses DC 5) and is resistant to voltage noise.

In each of the above-mentioned embodiments, the forward/reverse motor driver 545 is used to drive the DC motor 546 and change its rotation direction, but the driving method using a relay shown as a conventional example in FIG. Needless to say, you can adopt it. Further, in this embodiment, the illumination angle of the headlight is adjusted by manually operating the operation switch 42 in the set voltage extraction circuit 4, but for example, when a sensor signal from a tilt angle sensor is The configuration may also be such that the connection mode on the operation switch 42 is automatically changed over to adjust the irradiation angle of the headlight. Furthermore, in this embodiment, the irradiation angle of the headlights is adjusted in the vertical direction, but it will be explained that the present invention can also be applied to adjust the irradiation angle of the headlights in the horizontal direction. Not even.

〔Effect of the invention〕

As explained above, according to the irradiation angle adjustment device for a vehicle headlamp according to the present invention, different values can be obtained by switching the extraction position of the divided voltage with respect to the resistor means, which is formed by applying a power supply voltage to both ends of the resistor means. The piezoelectric voltage is taken out as a set voltage, and a divided voltage taken out from a reference resistor means formed by applying a power supply voltage to both ends thereof is set as a reference voltage, and this reference voltage and the set voltage are compared. Based on the comparison result between the reference voltage and the set voltage, an output signal is generated according to the comparison result, and the irradiation angle of the headlight on the vehicle is varied to a position determined according to the generated output signal. By arranging the resistance means on the inside of the vehicle and directing the set voltage taken out from the resistance means to the outside of the vehicle, at least the number of connection lines drawn into the inside of the vehicle can be applied to both ends of the resistance means. It is now possible to use a total of three lines, including the power supply voltage line and the lead-out line for the set voltage above, making the wiring hole from the outside of the car to the inside of the car smaller, reducing the noise in the engine room that is led from the wiring hole to the inside of the car. be able to suppress it. In addition, since there are fewer connection lines, it is easy to take waterproof measures against rainwater that is led into the car through the connection lines from the headlights placed outside the car, and the wiring work is also easy. It has excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the irradiation angle adjustment device for a vehicle headlamp according to the present invention, and FIGS. 2 to 4 show other circuits in the drive unit of this irradiation angle adjustment device. FIG. 5, which is a diagram showing an example of the configuration, is a diagram showing the operating principle of a conventional irradiation angle adjustment device. 3...Battery, 4...Setting voltage extraction circuit, 41.
・・Setting voltage extraction resistor, 42 ・・Operation switch, 5・
... Drive unit, 51 ... Reference voltage setting resistor, 52
... Voltage comparison circuit, 53 ... Output signal generation circuit, 5
4... Variable illumination angle circuit, 55... Fail safe circuit, L a w L b... Connection line. Patent applicant: Koito Manufacturing Co., Ltd.

Claims (1)

[Claims] A set voltage extraction means for extracting divided voltages of different values as a set voltage by switching the extraction position of the divided voltage with respect to the resistance means formed by applying a power supply voltage to both ends thereof, and a power supply voltage being applied to both ends thereof. a reference voltage setting means for setting a divided voltage taken out from a reference resistance means consisting of a reference voltage as a reference voltage; and a voltage comparison means for comparing a reference voltage set by the reference voltage setting means with a set voltage taken out by the set voltage taking out means. and an output signal generation means for generating an output signal according to the comparison result based on the comparison result of the voltage comparison means, and a headlight of the vehicle at a position determined according to the output signal generated by the output signal generation means. 1. An irradiation angle adjustment device for a vehicle headlamp, comprising irradiation angle variable means for varying the irradiation angle.