JPH0829536A - Method and apparatus for detecting optical axis - Google Patents

Abstract

PURPOSE:To detect the shift of optical axis in a distance measuring apparatus easily and accurately. CONSTITUTION:The laser head 40 of a distance measuring apparatus 10 is set at a height of 35cm from a pavement 30. A single laser light having small diameter is emitted from the laser head 40 in one of eight directions. When the optical axis of the apparatus 10 is directed in a reference direction, the laser lights in three downward direction among eight directions are reflected at the point P, Q or R on the pavement 30. The apparatus 10 then measures the distance to the reflecting point. When the apparatus 10 is mounted on an automobile, shift of the optical axis can be detected with reference to the distances to the points P, Q and R.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical axis detecting method and device suitable for use in a distance measuring device for measuring a distance between vehicles using a laser beam.

[0002]

2. Description of the Related Art There is known a distance measuring device for measuring a distance from a detection target by irradiating an electromagnetic wave represented by a laser beam to a detection target, receiving the reflected light thereof, and detecting a propagation delay time. There is.

FIG. 13 is a diagram showing a configuration example of a conventional distance measuring device. The control circuit 1 including a CPU or the like outputs a laser light emission command to the LD (laser diode) drive circuit 2 at a predetermined timing. LD drive circuit 2
Is the laser diode (L
D) Cause 3 to emit laser light. At this time, the control circuit 1
Starts the built-in timer counter. LD3
The laser light emitted from is reflected by a detection target (not shown).

A photodiode (hereinafter referred to as PD) 4 as a light receiving portion receives the laser light reflected by the detection target. The light receiving circuit 5 outputs a detection signal of laser light reception to the control circuit 1 when the reflected laser light received by the PD 4 has an intensity equal to or higher than a predetermined level set in advance. When the control circuit 1 receives this detection signal, it stops the timer counter, measures the propagation delay time, and calculates the distance to the detection target from this propagation delay time.

By the way, in the distance measuring device 10, the LD
It is necessary that the optical axis of the laser light emitted by 3 is adjusted to face the detection target.

For example, as shown in FIG.
0 is placed at the front of the automobile 101 and the other automobiles 102
When measuring the distance between and, the optical axis of the laser light emitted by the LD 3 in the distance measuring device 10 needs to be oriented toward the automobile 102. Therefore, when the distance measuring device 10 is attached to the automobile 101, it is necessary to adjust the optical axis of the laser beam emitted from the LD 3 so as to be oriented in an appropriate direction.

Conventionally, the following methods have been used as methods for adjusting the optical axis.

The first method is a method of adjusting the position of the optical axis in the vertical direction using a level.

The second method is to make the range finder emit light.
In front of the distance measuring device, a detection target composed of a reflector or the like is moved vertically and horizontally to
This is a method of adjusting the optical axis while confirming the detection area of the distance measuring device by receiving the light reflected from the detection target.

A third method is to install an adjusting mirror on the front surface (light emitting / receiving surface) of the distance measuring device, illuminate the mirror surface of the adjusting mirror with a flashlight, etc., and reflect the reflected light with the naked eye. Look at
This is a method of adjusting the optical axis of the distance measuring device by inspecting at which angle the light should be emitted.

The fourth method irradiates the detection object with three multi-beams, receives the reflected light, detects which multi-beam detects the detection object, and always detects the multi-beam at the center. Is a method of automatically adjusting the device so as to detect the error.
It is disclosed in Japanese Patent No.

[0012]

However, the above-mentioned method of adjusting the optical axis has the following problems. First, in the first adjusting method, although vertical adjustment is possible, horizontal adjustment is not possible. In addition, manufacturing precision for the casing and the optical axis is required.

The second adjustment method is very time-consuming and requires a plurality of personnel for the adjustment.

The third adjusting method indirectly adjusts the optical axis of the distance measuring device with an adjusting mirror and a flashlight. As a result, the positional relationship between the optical axis of the distance measuring device and the mirror axis of the adjusting mirror requires high precision, which makes the manufacturing process very difficult. In addition, if the adjustment mirror manufacturing process lacks rigor, the accuracy of the optical axis adjustment decreases.

According to the fourth adjusting method, although horizontal adjustment is possible, vertical adjustment is not possible.

The present invention has been made in view of such a situation, and an object thereof is to make it possible to detect the optical axis easily and accurately.

[0017]

An optical axis detecting device according to a first aspect of the present invention is a light emitting means for emitting light for irradiating a predetermined surface at a predetermined angle (for example, the LD3 of FIG. 1 and the two-dimensional scanner 11). ), Light receiving means for receiving the reflected light of this light from this predetermined surface (for example, PD 4 in FIG. 1), and detection means for detecting the direction of the reflected light from this predetermined surface (for example, FIG. 1).
Control means 1) and the output of this detection means, the determination means for determining the deviation of the optical axis of the light emitted from the above-mentioned light emitting means from the reference direction (for example, the optical axis determination device 1 in FIG. 1).
3) and are provided.

The above-mentioned light emitting means (for example, LD3 in FIG. 1,
The two-dimensional scanner 11) may be provided with a scanning means for operating light (two-dimensional scanner 11 of multi-fly 1), and the scanning means scans the light so that the predetermined surface described above is obtained. However, the light can be emitted at the above-mentioned predetermined angle.

This scanning means (for example, the two-dimensional scanner 11 in FIG. 1) can be composed of two galvano mirrors (for example, the galvano mirrors 21 and 22 in FIG. 2).

The above-mentioned predetermined surface is a road surface (for example, the road surface 30 in FIG. 5), and the above-mentioned light emitting means (for example, the LD in FIG. 1).
3, the two-dimensional scanner 11 and the control circuit 1) are adapted to change the light emission intensity at least according to the condition of the road surface or shift the above-mentioned predetermined angle to emit light. You can

This optical axis detecting device may be further provided with a notifying means (for example, the optical axis position notifying circuit 14 in FIG. 1) for notifying the determination result of the above-mentioned determining means.

This notifying means (for example, the optical axis position notifying circuit 14 in FIG. 1) causes the determination result of the above-mentioned determining means (for example, the optical axis determining circuit 13 in FIG. 1) to be notified by displaying or sounding. You can

This optical axis detecting device has an adjusting means (for example, a horizontal optical axis shown in FIG. 12) for adjusting the optical axis of the light emitted from the light emitting means in the reference direction based on the above-mentioned determination result. Adjusting screw 90, vertical optical axis adjusting screw 91)
Further, it may be provided.

The light emitting means (for example, the LD 3 in FIG. 1 and the two-dimensional scanner 11) emits light for a predetermined time, and the detecting means (for example, the control means 1 in FIG. 1) changes the direction of the reflected light for the predetermined time. In the case of detection, the determination means (for example, the optical axis determination circuit 13 in FIG. 1) uses the reference value of the optical axis of the light emitted from the light emitting means based on the average value of the output of the detection means in the predetermined time. It is possible to determine the deviation from the direction.

The optical axis detecting method according to claim 9 irradiates a predetermined surface with light at a predetermined angle, receives the reflected light of the light from the predetermined surface, and receives the reflected light from the predetermined surface. Is detected, and the deviation of the optical axis of this light from the reference direction is detected from the detected light direction.

[0026]

The two-dimensional scanner 11 scans the laser light emitted by the LD 3 in the vertical and horizontal directions. The PD 4 receives the reflected laser light reflected on the road surface or the detection target. The optical axis determination circuit 13 determines the position of the optical axis from the output of PD4. The optical axis position notification circuit 14 receives the determination result of the optical axis determination circuit 13 and displays the position of the optical axis. Therefore, the position of the optical axis can be adjusted easily and accurately.

[0027]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of an embodiment of the distance measuring device of the present invention. The basic configuration of the distance measuring device 10 is
Since it is the same as the case in FIG. 13, the portions corresponding to the case in FIG. 13 are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. That is, the LD drive circuit 2 receives a light emission command of the LD 3 from the control circuit 1 at every predetermined timing, and causes the LD 3 to emit a laser beam at that timing.

A two-dimensional scanner 11 (details of which will be described later with reference to FIG. 2) composed of two galvanometer mirrors is controlled by the control circuit 1 so that the laser light emitted by the LD 3 is vertically and horizontally aligned. It is designed to scan in the direction. Further, the scanning position detecting circuit 12 detects the scanning position of the two-dimensional scanner 11 and outputs the detection result to the control circuit 1.

The PD 4 receives the laser light reflected by a detection target (not shown) and outputs a detection signal to the light receiving circuit 5. The light receiving circuit 5 compares the detection signal with a predetermined reference value, and the comparison result is obtained. The output is made to the control circuit 1. The control circuit 1 calculates the distance between the distance measuring device 10 and the detection target from the time from the emission of the LD3 to the reception of the PD4 (propagation delay time until the laser light reaches the detection target and returns to the PD4). In addition, the direction in which the detection target exists is detected based on the scanning position information of the two-dimensional scanner 11 input from the scanning position detection circuit 12, and the optical axis determination circuit 1
It is designed to output to 3.

The optical axis determination circuit 13 determines the position of the optical axis of the distance measuring device 10 from the output of the control circuit 1, outputs the determination result to the optical axis position notification circuit 14, and outputs the optical axis position notification circuit. Reference numeral 14 indicates the position of the optical axis of the distance measuring device 10.

Although the optical axis determination circuit 13 is shown separately from the control circuit 1 for convenience of explanation, the control circuit 1 is shown.
When it is configured by a CPU, it can be considered that the optical axis determination circuit 13 is substantially built in the control circuit 1.

FIG. 2 is a diagram showing a configuration example of the two-dimensional scanner 11 shown in FIG. Since the laser light emitted from the LD 3 shown in FIG. 1 is divergent light, this divergent light is converted into parallel light to prevent the diameter of the light from becoming unnecessarily thick (the thicker it is, the lower the resolution is). . Therefore, the collimator lens 20 that converts the divergent light into parallel light is arranged in the front part of the two-dimensional scanner 11.

The laser light emitted from the LD 3 is incident on the galvanometer mirror 21 in the two-dimensional scanner 11 via the collimator lens 20. Rotating galvano mirror 21
Scans the incident laser light in a horizontal plane and reflects it toward the galvano mirror 22. The rotated galvanometer mirror 22 scans the incident laser light in a vertical plane.

A polygon mirror or the like may be used instead of the galvanometer mirror.

The timing when the LD 3 emits a laser beam,
And the galvano mirrors 21 and 2 of the two-dimensional scanner 11
The rotation operation of 2 is controlled by the control circuit 1. Therefore, the detection area (scanning position) of the laser beam scanned by the two-dimensional scanner 11 is a detection area 23 of a substantially quadrangular meter, as shown in FIG. FIG. 3 shows the detection area 23 shown in FIG. 2 in an enlarged manner. Detection area 23
The size of the galvano mirror 22 is such that the angular width in the horizontal direction scanned by the galvano mirror 21 is 400 mrad.
The angular width in the vertical direction scanned by is 70 mrad, and the resolution of the detection area is 80 divisions in the vertical direction and 7 divisions in the vertical direction according to the light emission timing of the LD 3.

Next, the adjustment of the optical axis in the vertical direction will be described. As shown in FIG. 4, when the road surface 30 is detected by a multi-beam that simultaneously generates a plurality of light beams and a light beam that diffuses even if only one, the PD 4 detects from which point in the range D of the road surface. It is unclear whether the reflected light is received.

Therefore, in the present invention, as shown in the principle diagram of FIG. 5, one laser beam having a small diameter is used to scan a predetermined range. FIG. 5 is a radar head (portion from which laser light is emitted) 4 of the distance measuring device 10 shown in FIG.
It is the figure which looked at the state where 0 was set up from the ground at a height of 35 cm from the lateral direction. The control circuit 1 controls the light emission timing of the LD 3 and the operation of the two-dimensional scanner 11, and the galvano mirror 22 of the two-dimensional scanner 11 rotates, so that the radar head 40 vertically rotates in an angular direction at intervals of 10 mrad. One laser beam is L1 to L8,
Irradiation (scanning) is performed sequentially. Since the LD 3 always emits a laser beam that is converged into one thin line, it becomes clear from which point of the road surface 30 the PD 4 receives the reflected light.

Assuming that the reference optical axis of the distance measuring device 10 is set in the horizontal direction and the road surface 30 is horizontal, the laser light L8 emitted to the lowermost side is emitted from the radar head 40. It reflects at a point P on the road surface at a position of 1000 cm in the horizontal direction from a point (point O) on the road surface 30 directly below. Next, the laser beam L7 emitted downward is reflected at a point Q of 400 cm in the horizontal direction from the reflection point P of the laser beam L8, and the laser beam L6 emitted third downward is the laser beam L7. It is reflected at a point R of 900 cm in the horizontal direction from the reflection point Q of.

Therefore, the PD 4 has the laser light L respectively.
At the timing when 8, L7 and L6 are irradiated,
The laser light reflected at points P, Q and R on the road surface is received. The light receiving circuit 5 outputs a detection signal to the control circuit 1 when the light receiving output is equal to or higher than the reference value. The timing at which this detection signal is detected is the distance from the radar head 40 to each point P, Q, R (hence the point O to each point P, Q, R).
It should correspond to the distance to R).

FIG. 6 is a side view of the distance measuring device 10 actually arranged in the front part of the automobile 50.
The radar head 40 is located 35 cm from the ground. PD4 is the laser light L in this state.
The reflected lights of 8, L7 and L6 are received. The light receiving circuit 5 is
When the received light output is equal to or higher than the reference value, a detection signal is output to the control circuit 1. From this detection signal, the control circuit 1
The respective reflection positions (distances from the point o to the points p, q and r) of the laser beams L8, L7 and L6 are calculated and output to the optical axis determination circuit 13.

For example, when the optical axis is displaced upward from the reference direction, the positions of the points p, q and r are the points P, Q when the optical axis shown in FIG. 5 is set in the horizontal direction. It is displaced to the right in the figure from the positions of R and R. That is, o
-P, p-q, and q-r are distances between O-P, P-Q, and QR when the optical axis is oriented in the horizontal direction.
Each will be longer than the interval.

On the other hand, when the optical axis is shifted downward from the reference direction, the positions of points p, q and r are the points P, Q and when the optical axis shown in FIG. 5 is set in the horizontal direction. R
It shifts to the left in the figure from the position of. That is, op
, P-q, and q-r are shorter than O-P, P-Q, and QR when the optical axis is in the normal direction.

From the above, the optical axis determination circuit 13 evaluates the correctness of the optical axis in the vertical direction (determines the optical axis) by the following equation (1). S = {(distance between op)-(distance between O-P)} + {(distance between p-q)-(distance between P-Q)} + {(distance between q-r) )-(Q-R distance)} (1)

In the formula (1), by adjusting the optical axis so that S becomes zero, the deviation of the optical axis in the vertical direction can be corrected. For example, when S is a positive value, the optical axis is shifted upward, so the adjustment is performed so as to shift the optical axis downward, and when S is a negative value, the optical axis is downward. Since it is shifted to, the adjustment may be made so that the optical axis is shifted upward.

If the sum of absolute values is calculated in the expression (1), the expression (1) can be expressed as the following expression (2). T = | (distance between op)-(distance between O-P) | + | (distance between p-q)-(distance between P-Q) | + | (distance between q-r) )-(Distance between QR) | ... (2)

Also in this equation (2), the deviation of the optical axis in the vertical direction can be corrected by adjusting the optical axis so that T becomes zero. In the case of this expression, if the optical axis is shifted in either the upward direction or the downward direction, T increases corresponding to the shift.

In the above, the three points (p,
Although the distances of q and r) are sampled, it goes without saying that only one point may be used.

When the vehicle 50 is stopped, the deviation of the optical axis in the vertical direction is corrected by the above-described method, and further the deviation of the optical axis while the vehicle 50 is actually traveling is detected and corrected again. Is also possible. That is, the control circuit 1 and the optical axis determination circuit 13 keep the o during a certain time while the vehicle 50 is traveling.
The distances between −p, between p−q, and between q−r are measured, the average values thereof are calculated, and a new S as the vertical deviation of the optical axis during actual traveling is calculated from the equation (1). . Based on this S, it is possible to readjust the optical axis in the vertical direction.

In order to adjust the optical axis in the vertical direction as described above, the PD 4 must receive the laser light reflected on the road surface 30. However, if the reflectance of the laser light is different due to the difference in the color or material of the road surface 30, the PD 4 may not be able to receive the reflected laser light with the normal emission power of the LD 3. Therefore, depending on the condition of the road surface 30, the LD3
With the normal light emission power of, a special light emission mode that functions when the PD 4 cannot receive the laser light, and emits the laser light with a light emission intensity higher than the normal light emission power,
It is also possible to have LD3.

Depending on the condition of the road surface 30, FIG.
In the normal detection area 23 of the two-dimensional scanner 11 as shown in (a), the PD 4 may not be able to receive the laser light reflected on the road surface 30. In this case, as shown in FIG. 7B, by directing the laser light for scanning the road surface further downward, the detection area 23 is set to a normal area so that the PD 4 can receive the laser light reflected on the road surface 30. It is also possible to give the control circuit 1 a special detection mode for detecting the road surface by moving it below the position.

In this case, the two-dimensional scanner 11 scans a range below the scannable area 23A. As a result, the distance to the reflection point becomes shorter, and it becomes possible to obtain a stronger level of return light.

Next, the adjustment of the optical axis in the horizontal direction will be described. FIG. 8 is a view of the range finder 10 arranged in the front part of the automobile 50 as seen from directly above. First, as shown in the figure, the detection target 60 including a reflector or the like is arranged at a predetermined reference position in the detection area 23. That is,
First, the relative positions of the vehicle 50 and the detection target 60 are adjusted so that the detection target 60 is located on the line 55 directly in front of the vehicle 50. As a result, if the optical axis of the distance measuring device 10 is oriented in the reference direction (positioned on the line 55), values of 0 to 79 (as shown in FIG. 9) are obtained. The detection target 60 is located in the direction of the coordinate value 40 in the middle of the adjustment on the horizontal coordinate axis 61 having a milliradian).

Therefore, the laser light is scanned in the horizontal direction, and the return light (reflected light) from the detection target 60 is detected by the PD 4. As shown in FIG. 10, for example, when the laser light received by the PD 4 is a reflected (returned) laser light from a direction other than the coordinate value 40 of the coordinate axis 61, the optical axis in the horizontal direction is set to the normal direction. It has not been. In other words, if the detection target 60 is located at the coordinate value 40 of the coordinate axis 61, the optical axis is set in the normal direction, and if located at other coordinate positions, the optical axis is normal. It is not set in the right direction.

From the above, the optical axis determination circuit 13 evaluates the correctness of the optical axis in the horizontal direction by the following equation (3) (determines the optical axis). M = (detection coordinates of detection target 60) -40 (3)

40 in equation (3) is the coordinate axis 6 in FIG.
It is the coordinate value of the center of 1. For example, when the detection target 60 is detected at a coordinate position smaller than the coordinate value 40 of the coordinate axis 61, M in Expression (3) has a negative value, and the optical axis is arranged on the left side of the line 55 (upper side in FIG. 10). Has been done. When the detection target 60 is detected at a coordinate position larger than the coordinate value 40 of the coordinate axis 61, M has a positive value, and the optical axis is arranged on the right side (lower side in FIG. 10) of the line 55.

Therefore, if the device is adjusted so that M becomes zero, the optical axis can be arranged at a normal position.

The size of the detection area (width in the vertical direction or width in the horizontal direction) or resolution may be set to a value different from that of this embodiment.

As described above, the optical axis determination circuit 13 can detect the positions of the optical axes in the vertical and horizontal directions. The position of the optical axis determined by the optical axis determination circuit 13 is output to the optical axis position notification circuit 14. The optical axis position notification circuit 14 corresponds to the determination result of the optical axis determination circuit 13,
The position of the optical axis of the distance measuring device 10 is displayed.

FIG. 11 is a diagram showing a configuration example of the optical axis position notification circuit 14. As the optical axis position notification circuit 14, the display device 70 switches and displays the position of the optical axis in the vertical direction or the position of the optical axis in the horizontal direction. The position of the optical axis is displayed by turning on the LED 71, and the device is adjusted so that it is at the position of 40 in the horizontal direction and the position of JUST in the vertical direction. The larger the deviation of the optical axis, the more LE
The lighting position of D71 is displaced from the position of 40 or JUST.

FIG. 12 is a diagram showing another configuration example of the optical axis position notification circuit 14. This optical axis position notification circuit 14
In the case of the display device 80 as, an LED indicating the position of the optical axis
The device is adjusted so that 81 coincides with the position of the LED 82 indicating the normal optical axis position. Also in this case, the larger the deviation of the optical axis, the more the lighting position of the LED 81 deviates from the LED 82.

Further, instead of displaying the position of the optical axis as in the above-described display devices 70 and 80, the position of the optical axis may be notified by emitting a sound. in this case,
The position of the optical axis is announced and the device is adjusted by changing the volume of the sound volume, the height of the sound, or the change in the number of times of sound generation.

Based on the notification result of the optical axis notification circuit 14 described above, the user may adjust the distance measuring device 10 so that the optical axis faces the normal direction. FIG. 13 shows the distance measuring device 1.
The configuration example for adjusting the optical axis of 0 is shown. The user
The optical axis is adjusted by operating the horizontal optical axis adjusting screws 90a to 90d or the vertical optical axis adjusting screw 91a while looking at the notification result of the optical axis notifying circuit 14.

For example, when adjusting the optical axis in the horizontal direction,
First, the horizontal optical axis adjusting screws 90 (90a to 90a)
d) is loosened, and while watching the display result of the optical axis position notification circuit 14 (for example, the display result of the display device 70), the entire distance measuring device 10 is rotated in the horizontal plane, and the optical axis is in the reference direction. When facing, tighten the horizontal optical axis adjusting screw 90. Similarly, when adjusting the optical axis in the vertical direction,
First, loosen the vertical optical axis adjusting screw 91a (91b is fixed because it is a reference screw), and measure while looking at the display result of the optical axis notification circuit 14 (for example, the display result of the display device 70). The entire distance device 10 is rotated about the screw 91b in the vertical plane, and the vertical optical axis adjusting screw 91a is tightened when the optical axis faces the reference direction.

Further, the position of the optical axis can be automatically adjusted by the actuator in correspondence with the optical axis determination circuit 13.

When the distance measuring device 10 is arranged in the automobile 50 and the optical axis is adjusted as described above, the laser light emitted from the radar head 40 is emitted at least in the reference direction (optical axis direction). Since the laser beam generated can detect another vehicle running ahead, the inter-vehicle distance can be reliably measured.

As the PD 4, it is also possible to use a multi-divided PD in which the light receiving region is multi-divided and each receives only light from a predetermined direction. In this case, a two-dimensional scanner can be used as the light source, but a diffused light source can also be used.

[0068]

As described above, according to the optical axis detecting device and the optical axis detecting method of the present invention, the laser beam is applied to a predetermined road surface and the position of the optical axis is determined from the reflected light. Therefore, it becomes possible to detect and adjust the position shift of the optical axis easily and accurately.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a distance measuring device incorporating an optical axis adjusting device of the present invention.

FIG. 2 is a diagram showing a configuration example of a two-dimensional scanner 11 shown in FIG.

FIG. 3 is a diagram showing details of a detection area 23 shown in FIG.

FIG. 4 is a diagram illustrating a problem when a road surface is detected by multi-beams.

5 is a diagram showing a principle of adjusting an optical axis in a vertical direction of the distance measuring device 10 shown in FIG.

FIG. 6 is a diagram showing a state of laser light when the distance measuring device 10 shown in FIG. 1 is arranged in a front part of an automobile.

FIG. 7 is a diagram showing states of a normal detection area and a detection area in a special mode.

8 is a diagram showing a principle of adjusting an optical axis in a vertical direction of the distance measuring device 10 shown in FIG.

9 is an enlarged view of a part of the detection area shown in FIG.

FIG. 10 is a diagram illustrating a shift of an optical axis in the horizontal direction.

11 is a diagram showing a configuration example of an optical axis position notification circuit 14 shown in FIG.

12 is a diagram showing another configuration example of the optical axis position notification circuit 14 shown in FIG.

13 is a diagram showing an example of a mechanism for adjusting an optical axis of the distance measuring device 10 shown in FIG.

FIG. 14 is a block diagram showing a configuration of an example of a conventional distance measuring device.

15 is a diagram showing a state of an optical axis when the distance measuring device 10 shown in FIG. 14 is arranged in a front portion of an automobile.

[Explanation of symbols]

 1 control device 2 LD drive circuit 3 LD 4 PD 5 light receiving circuit 10 ranging device 11 two-dimensional scanner 12 scanning position detection circuit 13 optical axis determination circuit 14 optical axis position notification circuit 20 collimator lens 21, 22 galvano mirror 23 detection area 23A Scannable area 23S Detection area in special mode 30 Road surface 40 Radar head 50 Car 55 Center line of detection area 60 Detection target 61 Coordinate axis 70 Display device 71 LED 80 Display device 81,82 LED 90, 90a to 90d Horizontal optical axis adjustment Screws 91, 91a, 91b Vertical optical axis adjusting screws 101, 102 Automobiles

Claims (9)

[Claims] 1. A light emitting means for emitting light to be irradiated onto a predetermined surface at a predetermined angle, a light receiving means for receiving reflected light of the light from the predetermined surface, and a reflection from the predetermined surface. An optical axis comprising: a detection unit that detects the direction of light; and a determination unit that determines the deviation of the optical axis of the light emitted from the light emitting unit from the reference direction from the output of the detection unit. Detection device. 2. The light emitting means includes a scanning means for scanning the light, and the scanning means scans the light so that the predetermined surface is irradiated with the light at the predetermined angle. The optical axis detection device according to claim 1. 3. The optical axis detecting device according to claim 2, wherein the scanning means is composed of two galvanometer mirrors. 4. The predetermined surface is a road surface, and the light emitting means emits the light by changing at least the light emission intensity according to the condition of the road surface, or
The optical axis detection device according to claim 1, wherein the light is emitted with the predetermined angle shifted. 5. The optical axis detecting device according to claim 1, further comprising notifying means for notifying a determination result of the determining means. 6. The optical axis detecting device according to claim 5, wherein the notifying means notifies the determination result of the determining means by at least displaying or sounding the determination result. 7. The adjusting means for adjusting the optical axis of the light emitted from the light emitting means in the reference direction based on the determination result of the determining means. The optical axis detection device according to any one of claims. 8. In the case where the light emitting means emits the light for a predetermined time and the detecting means detects the direction of the reflected light for the predetermined time, the judging means detects the light at the predetermined time. 8. The optical axis detecting device according to claim 1, wherein a deviation of an optical axis of light emitted from the light emitting means from a reference direction is determined from an average value of outputs of the means. 9. A method of irradiating a predetermined surface with light at a predetermined angle, receiving reflected light of the light from the predetermined surface, detecting a direction of reflected light from the predetermined surface, and detecting A method for detecting an optical axis, wherein a deviation of the optical axis of the light from a reference direction is detected based on the detected direction of the light.