JPS608730A - Measuring device of cut line of headlight beam - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for measuring the cut line or downward angle of a passing beam projected from a headlamp of an automobile, and more specifically, to a device for measuring the cut line or downward angle of a passing beam projected from a headlamp of an automobile. Relating to a device for measuring the cut line position or downward angle when the headlamp is set to a low beam in a switchable headlamp that has a cut line at least when the headlamp is set to a low beam. It is.

As a safety standard for road transport vehicles, the downward angle of the low beam projected from the headlights of automobiles is regulated. Recently, halogen lamps, which have excellent performance in terms of durability and brightness, have been widely used as light bulbs for headlamps. Furthermore, various countries around the world have various regulations regarding the safety standards for the driving beams and passing beams projected from headlamps, and these safety standards have changed in various ways due to the development of industry and trade.

The present invention was made in view of these circumstances, and
It is an object of the present invention to provide a device that can cope with the diversification of headlamps and standards for running beams and staggered beams and accurately measures the cut-line position or angle of the beam projected from the headlamp. That is, headlamps of automobiles can normally be switched between a running beam that can illuminate a relatively long distance and a passing beam that can illuminate a relatively short distance, which is used when there is an oncoming vehicle. in this case,
Although not limited to halogen lamps in particular, headlamps that are configured to emit light only to one side of the critical line formed when using a passing beam have come to be widely used. Such a critical line is usually called a cut line, and it must be ensured that this cut line has a predetermined position or downward angle so as not to dazzle the driver of an oncoming vehicle when used as a passing beam. is important, and for this reason conventionally the pattern irradiated onto a flat plate has been judged visually, but the present invention has been made by focusing on this point.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. As shown in FIG. 1, the apparatus of this embodiment consists of a dark box 1. Condensing lens 2. Mirror 3. Universal joint 4. Screen 5. Charging current difference meters 6a, 6b and 5c, frequency meter 7
a and 7b, and a transmission section 8. A dark box 1 is disposed opposite to the front of a headlamp 9 of an automobile.

A condenser lens 2 is mounted on the surface of the dark box 1 facing the headlamp 9.
is installed. The inside of the dark box 1 is hollow, and has a structure in which no external light is allowed to enter, except for the condensed beam passing through the condensing lens 2. The condensing lens 2 has a function of condensing the light emitted from the headlamp 9, and it is desirable that the diameter of the condensing lens 2 is at least larger than the external dimension of the headlamp 9 in the vertical direction. Further, the configuration of the condenser lens 2 and the arrangement of the dark box 1 are such that the upper and lower ends of the headlamp 9 are located within the height range of the upper and lower ends of the condenser lens 2. A screen 5 is provided above the condensing lens 2 of the dark box 1. A mirror 3 is arranged so as to reflect the beam passing through the condensing lens 2 and condense it onto a screen 5. Note that it is desirable that the optical path distance from the condenser lens 2 to the screen 5 be the same as the focal length of the condenser lens 2. The mirror 3 is connected to a universal joint 4 and can tilt vertically and horizontally, and is aligned with the center line 1 of the condenser lens 2.
The center of rotation of the mirror 3 is located above 0.

This universal joint 4 is connected to an angle meter (
By rotating each of the dials 7a and 7b, the mirror 3 can be rotated vertically and horizontally via a transmission section 8 made of gears, chains, etc., for example. Alternatively, the beam from the condenser lens 2 may be directly incident on the screen 5 disposed on the center line 10 of the condenser lens 2 without providing a mirror or the like in the optical path. In this case, the dimensions of the dark box 1 in the direction of the optical axis 10 and the arrangement position of the screen 5 are preferably determined in consideration of the focal length of the condenser lens 2. Further, in this case, it is preferable that the screen 5 be moved vertically and horizontally by rotating the dials of the angle meters 7a and 7b through a transmission section.

On this screen 5, as shown in FIG. 2, a reference vertical line 11 is provided in the vertical direction, and a reference horizontal line 12 is provided perpendicularly to this reference vertical line. Further, a reference cut line 13 may be provided downward from this reference horizontal line 12 at a position of a reference downward angle of a passing beam determined by safety standards. A photoelectric sensor G is provided at the intersection of the reference vertical line 11 and the reference horizontal line 12 in order to measure the luminous intensity of the beam projected from the headlamp 9.

On the reference horizontal film 12, photoelectric sensors C and D having the same performance are arranged on both sides of the photoelectric sensor G at positions equidistant from each other. Similarly, on the reference vertical 1i111, photoelectric sensors E and F having the same performance are arranged at positions equidistant above and below the photoelectric sensor G. On the right side of the photoelectric sensor D disposed on the reference horizontal line 12, a pair of photoelectric sensors A and B having the same performance are disposed one above the other and facing each other with the reference horizontal cotton 12 in between. In this case, it is desirable to arrange the light receiving surfaces of the photoelectric sensors A and B as close to the reference horizontal line 12 as possible,
Furthermore, it is preferable that the light receiving surfaces of the photoelectric sensors A and B have a shape that is elongated along the reference horizontal line 12. Further, a plurality of pairs of photoelectric sensors A and B may be arranged along the reference horizontal line 12, or photoelectric sensors A and B may be arranged opposite to each other on both sides of the reference cut line 13.

It is preferable to use photovoltaic elements or photoconductive elements as these photoelectric sensors. An example of using a photovoltaic element as a photoelectric sensor will be described below. As shown in FIG. 3, the wiring of photoelectric sensors A and B is connected to one electrode of photoelectric sensor A,
This electrode is connected to an electrode of photoelectric sensor B having the same polarity. Then, the other electrode of the photoelectric sensor A and the electrode of the photoelectric sensor B having the same polarity as the other electrode are connected to the charging current difference meter 60, respectively. In Fig. 3, photovoltaic element A
and B are connected to each other, and each anode is a charging current difference meter 6.
Connect to 0. If a photoconductive element is used, the connection may be made in the same manner. When two photovoltaic elements and a charging current meter are connected in this way and a beam is incident on the two photovoltaic elements, currents in opposite directions are generated in this closed circuit 14 depending on the amount of incident light. The current difference is the charging current difference meter 6.
Displayed as 0. Note that the charging current meter 60 is attached to the outside of the dark box 1. In addition, when multiple pairs of photoelectric sensors are arranged along the reference horizontal axis, one set of photovoltaic elements with electrodes of the same polarity connected to each other as shown in FIG.
It is better to connect them in parallel. When a set of photovoltaic elements are connected in parallel in this way, more accurate measurement is possible than when a single set of photovoltaic elements is used, and the current generated in a closed circuit is will also become larger. As described above, when one electrode of one photoelectric sensor is connected to the electrode of the other photoelectric sensor that has the same polarity as that electrode, and the other two electrodes are connected to the charging current meter. In this case, there is no need to separately provide a predetermined element or circuit to take the difference between the photocurrents output from the two photoelectric sensors, amplify the difference, and input the difference into the charging current difference meter.

The photoelectric sensors C and D are connected to an amplifier 15 as shown in FIG.
a, and the amplifier 15a is connected to the charging current difference meter 6a. When the photocurrents output from the photoelectric sensors C and D are input to the amplifier 15a, the difference between the two photocurrents is amplified and the charging current difference is displayed on the charging current difference meter 68.

Similarly, photoelectric sensors E and F are connected to an amplifier 15b, and the amplifier 15b is connected to a charging current meter 6b.

The photoelectric current output from the photoelectric sensors E and F is transmitted to the amplifier 1.
5b, the difference between the two photocurrents is amplified, and the charging current difference is displayed on the charging current difference meter 6b. Further, as in the case of photoelectric sensors A and B, photoelectric sensors C and D and photoelectric sensors E and F may be connected as shown in FIG.

Next, the operation of the apparatus of this embodiment will be explained.

After stopping the car at a predetermined position in front of the dark box 1, as shown in FIG. Adjust the installation height of the dark box 1 so that the lower end is located.

Next, the headlamp 9 is turned on to project a running beam 16 as shown in FIG. The traveling beam 16 shown in FIG. 6 is represented by an isolux curve. As shown in FIG. 1, the running beam 16 projected from the headlamp 9 enters the condenser lens 2, where the beam is converted into a converged beam, travels straight through the dark box 1, and is reflected by the mirror 3. and illuminates the screen 5. For this reason, screen 5
The traveling beam 16 is incident on photoelectric sensors C, D, E, F, and G provided above. It is possible to measure the luminous intensity of the traveling beam by the photocurrent output from the photoelectric sensor G. Then, the photocurrents from the photoelectric sensors C and D are output to the amplifier 15a as shown in FIG. 5, and the amplifier 15a amplifies the difference between the two photocurrents and outputs it to the charging current meter 6a .

Next, the inspector manually turns the dial of the angle meter 78 so that the photocurrent difference becomes zero while visually observing the photocurrent difference displayed on the charging current difference meter 6a. Therefore, angle meter 7
Universal joint 4 is connected via transmission part 8 by rotation of dial 8.
The mirror 3 is rotated in the left and right direction, and the traveling beam 16
moves in the horizontal direction along the reference horizontal line 12 of the screen 5, and aligns the vertical optical axis 18 of the traveling beam 16 with the screen 5.
The horizontal center of the traveling vehicle 16 and the horizontal center of the reference horizontal line 12 coincide with each other.

The photocurrent from the photoelectric sensors E and F is as shown in FIG.
It is output to the amplifier 15b, and in the amplifier 15b, 2
The difference between the two photocurrents is amplified and output to the charging current difference meter 6b. The inspector manually rotates the dial of the angle meter 7b so that the photocurrent difference becomes zero while visually observing the photocurrent difference displayed on the charging current difference meter 6b. Therefore, the angle meter 7b
The mirror 3 is rotated vertically by the rotation of the die A, and the traveling beam 16 aligns with the reference vertical line 11 of the screen 5 and moves vertically, so that the horizontal optical axis 17 of the traveling beam 16 and the horizontal optical axis 17 of the screen 5 are aligned. The reference horizontal line 12 coincides with the vertical center of the traveling beam 16 and the vertical center of the reference vertical 1!1111, and the alignment of the traveling beam 16 and the screen 5 is completed. The completion of this alignment means that the measurement of the optical axis center position of the traveling beam is completed, and the optical axis center is indicated by the angle meter dials 7a and 7b.

Next, the headlamp 9 is switched from the driving beam to a passing beam 19 as shown in FIG.

The passing beams shown in FIG. 7 are represented by isolux curves. A passing beam 19 projected from the headlamp 9 travels in the same way as the running beam 16 and illuminates the screen 5. For this reason, the passing beam 1 as shown in FIG.
The passing beam 19 is incident on the photoelectric sensors A and B according to the position of the upper end line of the screen 9, that is, the cut line 20, with respect to the reference horizontal line 12 of the screen 50.

Next, the inspector rotates the dial of the angle meter 7b, rotates the mirror 3 in the vertical direction via the transmission part 8 and the universal joint 4, and aligns the passing beam 19 with the reference vertical line of the screen 5. 11. Move it upward or downward along the ink.

For this reason, since the photoelectric sensors A and B are connected as shown in FIG. 3 to form a closed circuit 14, the vertical movement of the passing beam 19 causes the passing beam 19 to be incident on the photoelectric sensor B, for example. When almost no light is incident on the photoelectric sensor A, a photocurrent larger than the photocurrent generated from the photoelectric sensor A in the direction of the arrow 21' is generated in the closed circuit 14 from the photoelectric sensor B in the direction of the arrow 21', and the photocurrent is generated in the closed circuit 14. The difference between light and current becomes maximum, and the pointer 22 shows maximum deflection. Also, when equal amounts of light are incident on photoelectric sensors A and B,
Since the photocurrents generated from the photoelectric sensors A and B in the directions of arrows 21 and 21' are equal in value, they cancel each other out, and the charging current difference meter 60 displays an indication that the photocurrent difference is zero. In this way, the photocurrent difference displayed on the charging current difference meter 60 due to the respective photocurrents flowing in the closed circuit 14 in response to the light incident on the photoelectric sensors A and B can be changed by moving one passing beam. , exhibits photocurrent dynamic characteristics as shown in FIG. In FIG. 8, the vertical axis 23 represents photoelectric sensor A and photoelectric sensor B.
This corresponds to the photocurrent difference generated from the horizontal axis 2
4 indicates the upper and lower positions of the cut line of the passing beam for the photoelectric sensors A and B. That is, in FIG. 8, the photocurrent difference on both sides of the photocurrent dynamic maximum point 26 of the charging current difference waveform 25 gradually decreases and reaches the photocurrent dynamic zero points 27 and 27-. When the photocurrent amount reaches the zero point 27, a passing beam of equal illuminance is incident on the photoelectric sensors A and B, and when the photocurrent amount reaches the zero point 27-, there is a passing beam on both the photoelectric sensors A and B. is not incident.

Then, when the amount of photocurrent reaches the maximum value point 26, the passing beam almost never enters the photoelectric sensor A and exclusively enters the photoelectric sensor B. FIG. 9 shows the photoelectric characteristics of the photoelectric sensor. The vertical axis 28 represents photocurrent, and the horizontal axis 29 corresponds to the vertical position of the screen 5. In FIG. 9, when almost no beam is incident on the photoelectric sensor A and the beam is incident on the photoelectric sensor B, the area 30 is the area 30 of the photoelectric sensor B when the light receiving surface of the photoelectric sensor B occupies the area 132B of the horizontal axis 29. The area 31 shows the amount of photocurrent output from the photoelectric sensor A when the light receiving surface of the photoelectric sensor A occupies the area 32A of the horizontal axis 29.

The inspector manually rotates the dial of the angle meter 7b to move the passing beam vertically with respect to the screen 5, that is, to scan the screen 5 with the beam 19, which is displayed on the photocurrent meter 60. When the maximum value of the amount of photocurrent is found, the rotation of the dial of angle g17b is stopped and the mirror 3 corresponding to the amount of movement of the passing beam at that time is found.
By reading the rotation angle from the angle meter 7b, the downward angle of the cut line 20 of the passing zero beam 19 can be measured.

Next, another embodiment of the present invention will be described.

This embodiment device replaces the photoelectric sensors A and B in the previous embodiment with the third
As shown in the figure, the inspector automatically detects the maximum value of the difference in the photocurrent output from each photoelectric sensor power while visually checking the photocurrent meter, and the beam cut line is automatically detected. It is characterized by automatically measuring the position or downward angle of. As shown in the perspective view of FIG. Potentiometers 34a and 34b, servo motors 35a and 35b.

It has gears 368, 36a-, 36b, 36b-, rotating shirts h 37a and 37b, limit switches 38a and 38b, and as shown in the block diagram in FIG. ．． Peak position detection section 41, display sections 42a and 4
2b, amplifier 43a.

43b, 43c, photoelectric sensors A, B, C, D, E.

It is composed of F.

As shown in the figure, the servo motor 35a is controlled by a motor control section 39.
It is driven and rotated by a signal from a. Servo motor 35
A gear 36a is attached to the rotating shaft of a.
This gear 36a is provided with a dog 44, which is arranged so as to be able to come into contact with the limit switch 38a or 38b by rotation of the servo motor 35a. The gear 36a is in contact with the gear 35a = so as to be able to transmit power, and the gear 36a- can be rotated at a predetermined rotational speed by the rotation of the gear 36a. A rotary shaft 37a having a function as a feed screw is pivotally supported at the rotation center of the gear 36a-, and the rotation of the gear 36a- causes the shaft 3
7a is also configured to rotate integrally. A sliding contact 45a of a potentiometer 34a is attached to the rotating shaft 37a, and is movable in the vertical direction by rotation of a servo motor 35a. Potentiometer 34a
The structure is such that a change in the position of the sliding contact 45a is converted into an electrical signal. The sliding contact 4.58 is triple-coupled with the screen 33 via a connecting member, and is a mechanism for moving the screen 33 in the vertical direction in conjunction with the vertical movement of the sliding contact 45a. There is.

Like the servo motor 35a, the servo motor 35b can also be driven and rotated by a signal from the control section.
A gear 36b is attached to the shirt 1~.勺－
motor 35b, gears 361) and 36b-, rotating shaft 37b, sliding contact 45b, potentiometer 3
4b has the same configuration as the series of mechanisms described above, except that it moves the screen 33 in the left and right direction. Further, photoelectric sensors A, B, C, D, E, and F are arranged on the screen 33 in the same manner as in the previous embodiment.

As shown in FIG. 11, photoelectric sensors C and D are connected to an amplifier 43.
b, and the amplifier 43b amplifies the difference between the photocurrents output from the photoelectric sensors C and D and outputs it to the motor control section 39b. A switch 46 is provided between the amplifier 43b and the motor control section 39b, allowing selective connection between the amplifier 43b and the motor control section 39b.
The configuration is such that the servo motor 35b is operated until the difference between the photocurrents output from the servo motor 35b becomes zero, and a signal is output to the servo motor 35b to move the screen 33 in the left and right direction so as to track the vertical optical axis of the traveling beam. be. Further, signals indicating the distance that the screen 33 has moved in the left-right direction and the position of the screen 33 due to the operation of the servo motor 35b are output from the potentiometer 341) to the display section 42a.

The solid lines connecting the blocks in FIG. 11 represent electrical connections, and the dotted lines represent mechanical connections. The photoelectric sensors E and F are connected to an amplifier 43a, and the amplifier 43a
In this case, the difference in photocurrent is amplified and outputted to the terminal 47. The motor control section 39a is configured to be selectively connected to a terminal 47 or 48 by a switch 49. The motor control section 39a, like the motor control section 39b, is configured to output a signal to the servo motor 35a to operate the servo motor 35a until the photocurrent output from the photoelectric sensors E and F becomes zero. Due to the operation of the servo motor 35a, signals indicating the distance that the screen 33 has moved in the vertical direction and the position of the screen 330 are sent from the potentiometer 34a, and when the switch 50 is connected to the terminal 51, the signal passes through the peak position detection section 41 and is displayed on the display section. 42
This is the configuration shown in b. When the motor control m group 39a is connected to the terminal 48 by the switch 49, the gear 36a connected to the motor 35a rotates due to the operation of the servo motor 35a, and the dog 44 performs a planetary motion accordingly. When contacting the switch 38a, the limit switch 38a and the motor control unit 3
9a outputs a signal to the servo motor 358 to reverse the rotational direction of the servo motor 35a.

For this reason, the servo motor 35a operates with the rotation direction reversed, and the dozog 44 moves in the opposite direction as it rotates and contacts the limit switch 38b, which sends a signal to reverse the rotation direction of the servo motor in the same manner as described above. is output to the servo motor and this operation is repeated.

Photoelectric sensors A and B are connected in the same way as in the previous embodiment, but instead of an ammeter, an amplifier 43C is inserted into the closed circuit formed by photoelectric sensors A and B, and the amplifier 43c is connected to the peak signal detection section 40. has been done.

In the amplifier 43C, the difference between the photocurrents output from the sensors A and B is amplified and output to the peak signal detection section 40. The peak signal detection unit 40 is configured to detect the maximum point of the charging current difference waveform 25, that is, the peak of the waveform 25 as shown in FIG. 8, and output a peak hold signal to the terminal 52 when the peak is detected. It becomes. The switch 50 connects the terminal 52 and the peak position detection section 41, and the switch 49 connects the terminal 48 and the motor control section 39.
a is connected, the peak position detection unit 41 combines the vertical position signal of the screen 33 output from the potentiometer 34a and the peak hold signal output from the terminal 52. The position of the screen 33 when the charging current difference is maximum is detected, and the position signal at that time is output to the display section 42b.

Next, the operation of the device of this embodiment will be explained.

The entire device is arranged so that the screen 33 is located at an appropriate position in front of the headlamp 9. And switch 4
6 connects the amplifier 43b and the motor control section 39b, and the switch 49 connects the terminal 47 and the motor control section 39a.
The switch 50 connects the terminal 51 and the peak position detection section 41.

Next, the screen 33 is irradiated with the running beam 16 from the headlamp 9. Therefore, the traveling beam is incident on the photoelectric sensors C1D, E, and F, and photocurrents from the respective photoelectric sensors are outputted to amplifiers 43a and 43b, and the charging current difference is amplified and outputted to motor control units 39a and 39b. The motor controllers 39a, 39b output signals to the servo motors 35a, 35b to operate the servo motors 35a, 35b so as to make the input charging current difference zero. For this reason, the first
As shown in FIG. 0, the servo motors 35a and 3511 are driven to rotate and move the sliding contacts 45a and 45b up and down so as to track the vertical optical axis 18 and horizontal optical axis 17 of the traveling beam 16 via the gears and the rotating shirt. direction and move left and right. That is, the screen 33 is moved vertically or horizontally by the servo motors 35a and 35b until the reference horizontal line 12 and reference vertical line 11 of the screen as shown in FIG. It moves by rotation. When the photocurrent difference output from the photoelectric sensor becomes zero, the optical axis screen 33 of the traveling dome 16
alignment is completed and the servo motor stops operating. At this time, depending on the positions of the sliding contacts 45a, 45b, vertical and horizontal position signals of the screen 33 from the potentiometers 34a, 34b are displayed on the display sections 42a, 42b.

Next, the switch 46 cuts off the connection between the amplifier 4311 and the motor control section 39b, the switch 49 connects the motor control section 39a and the terminal 48, and the switch 50 connects the peak signal detection section 40 to the peak position detection section. 41.

Incidentally, it is preferable to provide a changeover switch for simultaneously performing such switching. Next, the headlamp 9 is switched from the driving beam 16 to the passing beam 19, and the servo motor 35a is activated.

Therefore, due to the rotation of the dog 44 attached to the gear 36a, the dog contacts the limit switch 38a or 38b, and a servo motor reversal signal is output to the servo motor 35a via the motor control section 39a.
The screen 33 reciprocates in the vertical direction by repeating inversions at a period corresponding to the period of contact of the dog 44 with the limit switch. When the screen 33 moves back and forth in the vertical direction, a passing beam 19 enters the photoelectric sensors A and B,
A photocurrent difference that changes as shown in the charge current difference waveform 25 shown in FIG. 8 as the screen 33 moves in the vertical direction is input to the peak signal detection unit 40 via the amplifier 43c. At the peak time, a predetermined signal is output to the peak time position detection section 41. At this time, the peak position detection unit 41 detects the screen position signal that is changing every moment due to the reciprocating movement of the screen 33 and detects the screen position signal on the potentiometer 34.
Since the screen position signal is input from a, the screen position signal is detected at the peak of the photocurrent difference and is output to the display section 42b. Based on the position signal displayed at this time, the downward angle of the passing beam or the position of the cut line from the reference horizontal line can be measured.

As described in detail above, according to the apparatus of the present invention, it is possible to accurately measure the downward angle or cut line position of the passing beam projected from the headlamp of an automobile. Additionally, it is possible to perform alignment using the running beam and measurement of the downward angle of the passing beam on the same screen, and it is also possible to perform measurements by installing the device at a position close to the headlamp. Therefore, it is also possible to perform measurements without being affected by external light other than the beam emitted from the headlamp. It is also possible to automatically measure the downward angle of the passing beam and align the optical axis of the traveling beam with the reference line of the screen. Note that the "reference (horizontal) line" used in this specification and claims does not necessarily need to be physically provided on the screen, and may be set virtually using an electric circuit or the like. Both are possible, and the present invention includes both of these.

In the embodiment of the present invention, the measurement of the downward angle of the passing beam for left-hand traffic has been described, but it is also possible to measure the downward angle of the passing beam for right-hand traffic using the apparatus of the present invention. As described above, the present invention is not limited to the specific embodiments described above, and it goes without saying that various modifications can be made within the technical scope of the present invention.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a measuring device according to an embodiment of the present invention, Fig. 2 is a schematic diagram showing a screen, Figs. 3 and 4 are circuit diagrams without showing the connection of the photoelectric sensor, and Fig. A block diagram showing how the photocurrent output from the photoelectric sensor is controlled,
Figure 6 is an isoluminance curve diagram of a traveling beam, Figure 7 is an isoluminance curve diagram of a passing beam, Figure 8 is a graph diagram showing the charging current difference, and Figure 9 is a graph diagram showing the photoelectric characteristics of a photoelectric sensor. 10 is a perspective view showing an automatic measuring device according to an embodiment of the present invention, and FIG. 11 is a block diagram regarding the automatic measuring device shown in FIG. 10. (Explanation of symbols) 1: Dark box 2: Condensing lens 3: Mirror 5, 33: Screens 6a, 6b
, 6c: Photocurrent difference meter 7a, 7b: Angle meter (dial) 9: Headlamp 16: Running beam 19: Passing beam 25: Charging current difference waveform 34a, 34b: Horn angle meter 35a, 3
5b: Servo motor 36a, 36a', 36b, 36b': Gear 3
7a, 37b: Rotating shaft (feed screw) 38a, 38b: Limit switch 44: Dog 45a, 45b: Sliding contacts A, B, C, D, E, F: Photoelectric sensor patent applicant Light Kogyo Co., Ltd. The) 8 Figure 9 Figure 10

Claims (1)

[Claims] 1. A cut-line measuring device for an irradiation beam from an automobile headlight, which comprises: a pair of photoelectric sensors movable relative to the irradiation beam; and the pair of photoelectric sensors. 1. A cutline measuring device comprising: detection means for detecting the cutline position of the irradiation beam based on the maximum value of the difference in photocurrent from the irradiation beam. 2. The device according to item 1 above, wherein each of the pair of photoelectric sensors has two positive and negative electrodes, and the electrodes of the same polarity are connected to each other to form a closed circuit. . 3. In the above item 1, the headlight is switchable between a driving beam and a passing beam, and the passing beam has a cut line, and when the driving beam is set as the driving beam, the headlight is switchable between a driving beam and a passing beam. An apparatus comprising four alignment photoelectric sensors arranged axially symmetrically to align the pair of photoelectric sensors with respect to the main optical axis of the apparatus. 4. In the above item 1, the device is characterized in that the photoelectric sensor is disposed in a dark box equipped with a condensing lens, and the irradiation beam is made incident on the photoelectric sensor via the condensing lens. . 5. In the above item 1, the irradiation beam from the headlight is reflected by a movable mirror and incident on the pair of photoelectric sensors, and by moving the mirror, the irradiation beam and the pair of photoelectric sensors are A device characterized in that it moves relative to a sensor. 6. In the above item 1, the detection means detects a peak signal that detects a maximum value of a difference between a photocurrent output from a υ-bo motor that reciprocates the photoelectric sensor in a predetermined direction and a photocurrent output from the photoelectric sensor. and a peak position detection unit that detects the position of the photoelectric sensor based on the signal from the peak signal detection unit and the signal from the potentiometer.