WO2017130944A1

WO2017130944A1 - Optical scanner

Info

Publication number: WO2017130944A1
Application number: PCT/JP2017/002294
Authority: WO
Inventors: 幸男篠塚; 正晴田島
Original assignee: シナノケンシ株式会社
Priority date: 2016-01-28
Filing date: 2017-01-24
Publication date: 2017-08-03
Also published as: JP2017134294A; JP6883738B2

Abstract

The present invention addresses the problem of providing an optical scanner with which it is possible to raise the measurement precision without increasing the size of the electric motor. As a solution, this optical scanner is provided with: a first electric motor (32); a rotary part (38) that can rotate via the rotational driving force of the first electric motor (32) with the vertical direction as the axis; a main reflecting mirror (34) that is attached to the rotary part (38), rotates together with the rotary part (38) with the vertical direction as the axis, shines the scanning light toward an object, and receives reflected light from the object; and a second electric motor (48) that is attached to the rotary part (38) and rotates the main reflecting mirror (34) with, as the axis, a direction having a predetermined angle relative to the horizontal plane.

Description

Optical scanning device

The present invention relates to an optical scanning device.

Conventionally, an optical scanning device using a laser beam for performing a three-dimensional distance measurement has been proposed. For example, configurations such as Patent Document 1 and Patent Document 2 are disclosed.

The optical scanning device disclosed in Patent Document 1 includes a flat plate reflecting mirror that rotates around both a horizontal rotation axis and a vertical rotation axis.
This flat reflector reflects the light emitted from the light emitting element into the measurement space and then reflects the reflected light reflected by the object in the measurement space again to send it to the light receiving element.
The flat reflector is supported by a mirror mount so as to rotate about a horizontal rotation axis. The mirror mount is provided with a rotating guide shaft that is inserted into a guide rail formed on the inner wall surface of the vertical moving body.
The flat reflector is provided so as to rotate about the vertical rotation axis by a rotating member to which a rotational force of a motor (electric motor) is applied.
For this reason, the flat mirror is rotated about the horizontal rotation axis and simultaneously rotated about the vertical rotation axis by the rotational drive of a single motor.

In addition, the optical scanning device disclosed in Patent Document 2 includes a mechanism that rotates a flat reflector around a vertical rotation axis and a horizontal rotation axis with a single motor. The rotational driving force of this motor is transmitted to a spur gear that rotates the gear box, and the gear box rotates about the vertical rotation axis.
A hollow worm gear that does not rotate is arranged at the center of the vertical rotation shaft.
The worm wheel that is screwed into the hollow worm gear is provided in the gear box, and is rotated by screwing with the worm gear as the gear box rotates.
A spur gear connected to the horizontal rotating shaft of the flat reflector is attached to the rotating shaft of the worm wheel. The flat plate mirror rotates about a horizontal rotation axis that rotates vertically integrally with the gear box.
That is, the flat mirror is rotated about the horizontal rotation axis and the vertical rotation axis by the rotational drive of a single motor.

Furthermore, in Patent Document 3, the vertical rotation speed and horizontal rotation in a mechanism for rotating a flat reflector by distributing the driving force of a single motor so that two rotation shafts, a vertical rotation shaft and a horizontal rotation shaft, are driven by a gear. It describes the setting of the rotation speed ratio. By setting this ratio to an appropriate ratio, it is possible to make the spatial density of optical scanning fine.

JP 2010-527024 A Japanese Patent No. 5620603 Japanese Patent Application No. 2015-008133

As described above, according to the conventional optical scanning device, the flat mirror is rotated or oscillated around the rotation axes of the horizontal rotation axis and the vertical rotation axis by one electric motor to irradiate the target light with the scanning light. is doing.
In particular, in the apparatus of Patent Document 3, the scanning lines by the optical scanning apparatus are formed obliquely with respect to the target space because they are scanned vertically and horizontally, and the oblique scanning lines are formed in all directions around the flat plate reflector. Is done. In this way, since the scanning lines are formed obliquely, there are more straight lines extending in the vertical direction and the horizontal direction, particularly when the measurement object is an artificial object. Accuracy is improved.

By the way, in the conventional optical scanning device, it is necessary to realize high-speed scanning in order to further reduce the interval between the scanning lines or shorten the time required for one cycle measurement.
In order to realize high-speed scanning, it is necessary to increase the rotation speed around the vertical rotation axis, but this requires an increase in the size of the electric motor. However, when the electric motor is increased in size, there is a problem that the increase in cost and cost must be studied for increasing the size and durability of other components.
Moreover, when rotating a vertical rotating shaft and a horizontal rotating shaft at high speed via a transmission mechanism etc., there exists a subject that the noise of a transmission mechanism etc. becomes large.

Further, unless the ratio of the rotation speeds of the vertical rotation axis and the horizontal rotation axis is set to an appropriate balance, the interval between the scanning lines cannot be reduced, and a small shape cannot be detected.
For example, in a state where the rotation speed about the horizontal rotation axis is several tens of times faster than the rotation speed about the vertical rotation axis, the scanning line becomes nearly vertical, It becomes difficult to detect the extending structure.
In this way, even if the electric motor is increased in size to increase the rotation speed around the vertical rotation axis, the necessary structure such as a transmission for adjusting the balance with the rotation speed around the horizontal rotation axis is also large. It will be necessary to make it more complicated.

Accordingly, the present invention is made to solve the above-described problems, and an object of the present invention is to provide an optical scanning device that can set the angle and interval of scanning lines freely and easily without increasing the size of the electric motor. There is.

According to the optical scanning device of the present invention, the first electric motor, the rotating part that can be rotated about the vertical direction by the rotational driving force of the first electric motor, and the rotating part are attached to the rotating part and together with the rotating part A main reflector that rotates about the vertical direction as an axis, irradiates scanning light toward the object and receives reflected light from the object, and a direction attached to the rotating unit and having a predetermined angle with respect to a horizontal plane. And a second electric motor that rotates the main reflecting mirror as an axis.
By adopting this configuration, the number of rotations of rotation (revolution) with the vertical direction of the main reflector as the axis and rotation with the direction having a predetermined angle with respect to the horizontal plane (rotation) are set separately. Is possible. For this reason, it is not necessary to provide a structure such as a transmission even when performing high-speed scanning, and high-speed scanning is possible without increasing the size of the entire apparatus, and the interval between scanning lines and the time required for measurement can be set flexibly. be able to. Further, the rotation of the main reflecting mirror does not use the horizontal direction as an axis, but uses a direction having a predetermined angle with respect to a horizontal plane as an axis. Therefore, even if the revolution speed (rotational speed in the vertical direction) is set lower than the rotation speed of the main reflecting mirror, the angle of the scanning line can be set appropriately by changing this angle. is there.

The reflecting surface of the main reflecting mirror has a predetermined angle other than an angle perpendicular to or parallel to the rotation axis of the second electric motor, and the reflecting surface of the main reflecting mirror includes the second electric motor. The scanning light may be incident in parallel to the rotation axis.
According to this configuration, the range in which the reflected light of the reflecting surface of the main reflecting mirror rotating around the rotation axis by the second electric motor can be received is the same area regardless of the rotation position of the main reflecting mirror. The amount of received light can be made constant regardless of the rotation angle.

The main reflecting mirror is formed such that a tip of a cylindrical rod extending along a rotation axis by the second electric motor is formed at a predetermined angle other than an angle perpendicular to or parallel to the rotation axis by the second electric motor. It may be a rod mirror having a reflecting surface.
According to this configuration, since the reflecting surface and the rotation shaft are configured by a single rod, the air resistance can be reduced and the wind noise can be reduced when the second motor is rotated around the rotation shaft. Can be reduced.

The rotation axis by the second electric motor may pass through the center of the reflecting surface of the main reflecting mirror, and the scanning light may enter the center of the reflecting surface of the reflecting mirror.
According to this configuration, when the main reflector is rotated, there is no change in the shape of the main reflector viewed from the direction of the rotation axis, so that the scanning light is irradiated to the object and irregularly reflected and returned to the main reflector. Reflected light, which is light, can be reflected stably without changing the amount of light depending on the rotational position of the main reflecting mirror.

In addition, a predetermined angle with respect to a horizontal plane of the main reflecting mirror may be adjustable.
According to this configuration, the predetermined angle with respect to the horizontal plane of the main reflecting mirror is adjusted so that the scanning lines are concentrated particularly on the area to be scanned, and the interval between the scanning lines in the area to be scanned is particularly reduced. Can do.

Further, the rotating shaft of the first electric motor is a hollow rotating shaft having a hollow inside so that the scanning light irradiated from below passing through the hollow rotating shaft is reflected toward the reflecting mirror. A follower mirror may be provided immediately above the hollow rotation shaft.

Further, the sub-reflecting mirror may be attached to the rotating unit and rotate with the rotating unit about a vertical direction as an axis.

According to the present invention, the angle and interval of the scanning lines can be set freely and easily while avoiding the noise problem of the speed change mechanism when high-speed scanning is performed without increasing the size of the electric motor.

It is explanatory drawing which shows schematic structure of an optical scanning device. It is a perspective view of an optical scanning device. It is a side view of an optical scanning device. It is explanatory drawing of a main reflective mirror. It is explanatory drawing which shows the place which rotated the main reflecting mirror shown in FIG. 4 180 degrees centering | focusing on the rotating shaft. It is explanatory drawing of the scanning line which generate | occur | produces when operating the spherical body when the angle with respect to the horizontal surface of a rotating shaft is 45 degrees. It is explanatory drawing of the scanning line which generate | occur | produces when operating the spherical body when the angle with respect to the horizontal surface of a rotating shaft is 60 degrees. It is explanatory drawing of the scanning line which generate | occur | produces when operating the spherical body when the angle with respect to the horizontal surface of a rotating shaft is 30 degrees. It is explanatory drawing which shows other embodiment of the main reflective mirror. It is a side view which shows embodiment at the time of employ | adopting a small laser distance measuring apparatus.

FIG. 1 shows a schematic configuration of the optical scanning device of the present embodiment, and first, an optical system will be mainly described.
The optical scanning device 30 irradiates an object around the optical scanning device 30 with the scanning light, acquires the shape of the surrounding space as point cloud data by reflected light from the surroundings, and measures the shape of the object. is there. As light, laser light is generally used.

The optical scanning device 30 is disposed above the first electric motor 32, the second electric motor 48, and the first electric motor 32 at a position shifted laterally from the rotation axis of the first electric motor 32. And a main reflecting mirror 34 for irradiating the object (not shown) with scanning light and receiving reflected light from the object.

The main reflecting mirror 34 is connected to the second electric motor 48 and is rotatable around a rotation axis A (rotation axis of the second electric motor 48) having an axis in a direction inclined by a predetermined angle with respect to the horizontal plane. In addition, it is provided so as to be rotatable about a vertical rotation axis Z integrally with a rotation unit 38 described later. The rotation axis A is provided so as to pass through the center of the reflecting surface of the main reflecting mirror 34.

The rotating shaft of the first electric motor 32 is a hollow shaft 36 whose center is hollow. A rotating portion 38 (see FIGS. 2 and 3) that is integrated with the hollow shaft 36 and rotates about the vertical rotation axis Z is fixed to the upper end portion of the hollow shaft 36. A main reflecting mirror 34 and a sub-reflecting mirror 50 are attached to the rotating portion 38.
The sub-reflecting mirror 50 is disposed directly above the hollow shaft 36 with its reflecting surface facing the main reflecting mirror 34. The sub-reflecting mirror 50 reflects the scanning light that has passed through the hollow shaft 36 from below toward the main reflecting mirror 34 and reflects the reflected light from the main reflecting mirror 34 so as to pass through the hollow shaft 36. .

Further, it is preferable that the scanning light incident on the main reflecting mirror 34 from the sub-reflecting mirror 50 is incident on the same straight line with respect to the rotation axis A, that is, incident on the center of the reflecting surface of the main reflecting mirror 34.
The reflecting surface of the main reflecting mirror 34 has a point-symmetric shape about the rotation axis of rotation, and there is no change in the external shape seen from the rotation axis direction due to the rotation position of the rotation axis of rotation of the main reflection mirror 34. By making the scanning light incident on the center of the reflecting surface of the main reflecting mirror 34, the reflected light, which is the light that is irregularly reflected by the scanning light incident on the object and returns to the main reflecting mirror 34, is reflected on the main reflecting mirror 34. It is possible to stably reflect the reflected light to a sub-reflecting mirror 50 described later without causing a variation in the amount of reflected light due to the rotational position of the rotation axis of rotation.

A lower reflecting mirror 45 is disposed below the hollow shaft 36 of the first electric motor 32. The lower reflecting mirror 45 has a function of introducing scanning light into the hollow shaft 36 and reflecting the reflected light that has passed through the hollow shaft 36 in the lateral direction.
The laser light emitting device 26 that outputs the scanning light is provided not at a position directly below the first electric motor 32 but at a position shifted in the lateral direction. The laser light emitting device 26 makes the scanning light incident on the lower reflecting mirror 45 through the plurality of mirrors 25.

When the scanning light is incident on the object, the scanning light is scattered and reflected by the object. The reflected light is reflected by the reflecting surface of the main reflecting mirror 34 and enters the sub-reflecting mirror 50. The subreflector 50 reflects the reflected light vertically downward. The reflected light reflected by the secondary reflecting mirror 50 passes through the hollow shaft 36 vertically downward.
The reflected light that has passed through the hollow shaft 36 vertically downward is incident on the laser light receiving device 28 via a light receiving optical system 27 that is constituted by a convex lens that is reflected by the lower reflecting mirror 45 and collects the reflected light. A data processing device (not shown) is connected to the laser light receiving device 28, and the distance from the reflected light received by the laser light receiving device 28 to the measurement object can be calculated. By detecting the angle, the direction in which the scanning light is irradiated can be calculated. It is possible to calculate the three-dimensional coordinate data based on these distance and direction information.
The data processing apparatus may be an ordinary personal computer or a dedicated machine for data processing.

Next, FIG. 2 is a perspective view of the optical scanning device according to the present embodiment, FIG. 3 is a side view thereof, and the mechanical configuration of the optical scanning device according to the present embodiment will be described.
As described above, the main reflecting mirror 34 rotates about the rotation axis A facing a direction having a predetermined angle with respect to the horizontal plane, and scans the scanning light in the vertical direction.
Further, the main reflecting mirror 34 is integrated with the rotating unit 38, rotates around the vertical rotation axis Z that is a rotation axis facing in the vertical direction, and scans the scanning light in the horizontal direction. The vertical rotation axis of this embodiment is a hollow shaft 36.

The rotating portion 38 fixed to the hollow shaft 36 includes a base portion 54 that is a portion fixed to the hollow shaft 36, a column portion 55 that extends upward from the base portion 54 and is attached with a follower mirror 50, and a base portion 54. And a main reflector mounting portion 57 extending obliquely upward.

The main reflecting mirror 34 and a second electric motor 48 that rotates the main reflecting mirror 34 are disposed in the main reflecting mirror mounting portion 57.
The main reflecting mirror 34 of this embodiment is a rod mirror having a reflecting surface in which the tip of a cylindrical rod is inclined at a predetermined angle that is an angle other than perpendicular or parallel to the axial direction of the rod (rotation axis A). Adopted. The rod mirror is a reflecting surface formed by cutting the tip of a rod formed of glass or the like at a predetermined angle and depositing a reflecting film such as metal on the cutting surface.
In the present embodiment, the predetermined angle is 45 °, but the predetermined angle is not limited to 45 °.

The second electric motor 48 is attached to the main reflecting mirror 34 so that the rotation axis A of the main reflecting mirror 34 has an angle of 45 ° with respect to the horizontal plane.
That is, the main reflector mounting portion 57 is also provided with an inclination of 45 ° with respect to the base portion 54 disposed in the horizontal direction.

In addition, a hinge part (not shown) etc. may be provided between the main reflector attachment part 57 and the base part 54, and the angle with respect to the horizontal surface of the main reflector attachment part 57 may be provided so that adjustment is possible. With such a configuration, the angle of the rotation axis A of the main reflecting mirror 34 with respect to the horizontal plane can be adjusted. The adjustment of the angle of the rotation axis A of the main reflecting mirror 34 with respect to the horizontal plane is not the adjustment of the angle of the main reflecting mirror mounting portion 57 with respect to the base 54, but the main reflecting mirror 34 and the main reflecting mirror mounting portion 57 of the second electric motor 48. The mounting angle may be adjustable.
When the angle of the rotation axis A of the main reflecting mirror 34 with respect to the horizontal plane is adjusted in this way, it is necessary to adjust the angle of the sub reflecting mirror 50 as well. For this reason, it is necessary to provide adjusting means such as a hinge (not shown) in the subreflector 50 as well.

In this way, by adjusting the angle of the rotation axis A of the main reflecting mirror 34 with respect to the horizontal plane, the range in which the scanning lines are concentrated can be adjusted in the vertical direction, and in particular, the interval between the scanning lines in the range to be scanned can be reduced. Can do. This point will be described later with reference to FIGS.

The optical scanning device 30 is provided with a base portion 39 at the lowermost portion, and the base portion 39 is configured as an installation surface on the ground or floor surface.
The first electric motor 32 is disposed on a base 40 provided above a predetermined distance from the base portion 39. Support pillars 41 for supporting the base 40 are respectively arranged at the four corners of the upper surface of the base portion 39.

A support column 33 extending from the base 40 toward the upper end of the rotating unit 38 is provided. A horizontal portion 35 extending in the horizontal direction is provided at the upper end of the column 33. The front end of the horizontal portion 35 extends to a position directly above the hollow shaft 36.
A wireless transmission / reception unit 44 is provided on the lower surface of the front end of the horizontal unit 35.
In addition, a wireless transmission / reception unit 46 capable of wireless communication with the wireless transmission / reception unit 44 is provided at a position facing the wireless transmission / reception unit 44 and on the upper surface of the rotation unit 38. For this reason, it is possible to perform communication between the rotation part 38 and the part which does not rotate.

The rotation unit 38 is equipped with a rotation control unit (not shown), a rotation drive unit (not shown), and a power source (not shown) of the second electric motor 48. Further, it is necessary to output rotation angle information from the rotation control unit to the outside of the rotation unit 38.
Therefore, a rotation angle signal is output from the rotation control unit to the wireless transmission / reception unit 46 through a wiring (not shown), and the wireless transmission / reception unit 44 provided in the horizontal unit 35 receives the rotation angle signal. By arranging the wireless transmission / reception unit 46 and the wireless transmission / reception unit 44 on the vertical rotation axis Z, even when the rotation unit 38 rotates, transmission / reception of wireless data can be satisfactorily performed. As wireless communication, communication means such as short-range wireless communication such as Bluetooth (registered trademark), wireless LAN, ZigBee (registered trademark), infrared light, and optical communication can be employed. In this embodiment, since a proximity type communication device is used, there is a measurement impossible range due to vignetting of measurement light. However, by using a different type of communication device, measurement without vignetting is possible.

4 and 5 are enlarged views of the main reflecting mirror 34. FIG.
The main reflecting mirror 34 of this embodiment inclines the tip of a cylindrical rod at a predetermined angle that is an angle other than perpendicular or parallel to the axial direction of the rod (rotational axis A having a predetermined angle with respect to the horizontal plane). A rod mirror with a reflective surface is used. The rod mirror is a reflecting surface formed by cutting the tip of a rod formed of glass or the like at a predetermined angle and depositing a reflecting film such as metal on the cutting surface.
In the present embodiment, the inclination angle with respect to the axial direction of the rod is 45 °, but this angle is not limited to 45 °.

4 and 5 of the present embodiment, the axis direction of the rotation axis A is set to be 45 ° with respect to the horizontal plane, but the angle of the axis direction of the rotation axis A is limited to 45 °. Not what you want.
The angle of the rotation axis A in the axial direction is preferably set in the range of 10 ° to 80 ° with respect to the horizontal plane.

The rotation axis A of the main reflecting mirror 34 is provided so as to coincide with the axis of the rod mirror and pass through the center of the reflecting surface.
By rotating the main reflecting mirror 34 around the rotation axis A, the scanning light incident parallel to the rotation axis A is always the same with respect to the reflection direction of the scanning light regardless of the rotation angle of the rotation axis A. Therefore, the reflected light from the object can be always received at the same level, and the distance measurement is stable regardless of the rotation angle of the rotation axis A.

According to the main reflecting mirror 34 of the present embodiment, the reflected light reflected from the object does not reduce the light receiving area of the reflected light depending on the angle even if the main reflecting mirror 34 rotates around the rotation axis A. Can be. For this reason, the point cloud data based on reflected light can be acquired reliably.
In addition, the light receiving area can be prevented from being reduced depending on the rotation angle without increasing the area of the reflecting surface of the reflecting mirror as in the case of the conventional scanning device. Resistance can be prevented from increasing, and noise and vibration can be reduced.

FIG. 6 shows scanning when the angle of the rotation axis A of the main reflector 34 with respect to the horizontal plane is 45 °, the rotation speed about the vertical rotation axis Z is 300 rpm, and the rotation speed about the rotation axis A is 10000 rpm. Shows the state of light.
According to this, the scanning light is scanned within a range of an elevation angle of 45 ° and a depression angle of 45 ° from the horizontal plane.
In this case, the upper and lower measurements are not performed, but the scanning lines are concentrated in the horizontal direction. Therefore, when the horizontal information of the measurement target is important, the scanning light is increased in the horizontal direction of the measurement target. Irradiation can be performed at a high density, and scanning with higher resolution becomes possible.

FIG. 7 shows scanning when the angle of the rotation axis A of the main reflecting mirror 34 with respect to the horizontal plane is 30 °, the rotation speed around the vertical rotation axis Z is 300 rpm, and the rotation speed around the rotation axis A is 10000 rpm. Shows the state of light.
According to this, the scanning light is scanned within the range of the elevation angle 60 ° and the depression angle 60 ° from the horizontal plane.
In this case, the measurable range is expanded on both the upper side and the lower side than the state of FIG.

FIG. 8 shows scanning when the angle of the rotation axis A of the main reflecting mirror 34 with respect to the horizontal plane is 60 °, the rotation speed around the vertical rotation axis Z is 300 rpm, and the rotation speed around the rotation axis A is 10000 rpm. Shows the state of light.
According to this, the scanning light is scanned in the range of the elevation angle 30 ° and the depression angle 30 ° from the horizontal plane.
In this case, measurement is performed only in a range of 60 ° in the vertical direction, but since the scanning lines are concentrated in this range, the information in the horizontal direction to be measured is more important than the state of FIG. This is effective when it is desired to carry out measurement in this range particularly precisely.

As shown in FIGS. 6 to 8, by changing the angle of the rotation axis A of the main reflecting mirror 34 with respect to the horizontal plane, the scanning location of the scanning light can be selected, and the location where measurement is to be performed more precisely On the other hand, it is possible to measure by increasing the density of the scanning lines.

In the above-described embodiment, the case where the rod mirror is employed as the main reflecting mirror has been described. However, the reflecting mirror is not limited to the rod mirror.
For example, as shown in FIG. 9, a rotation shaft 66 arranged on the same straight line as the horizontal rotation axis is attached to a flat plate reflecting mirror 64 having a reflection surface with a predetermined angle with respect to the horizontal rotation axis directed in the horizontal direction. It may be a configuration.

In the above-described embodiment, the laser light emitting device 26 and the laser light receiving device 28 (hereinafter collectively referred to as a laser distance measuring device) are shifted below the first electric motor 32 and in the lateral direction. An example of arranging at different positions has been described. This is because it is difficult to place a large laser distance measuring device with high distance measuring accuracy directly below the first electric motor 32 due to space problems.

On the other hand, according to the present invention, since the main reflecting mirror 34 is rotationally driven by the second electric motor 48, the main reflecting mirror 34 does not have to be disposed on the rotation axis of the first electric motor 32. Is arranged at a position shifted laterally from the rotation axis of the first electric motor 32. For this reason, a space is created immediately above the first electric motor 32.

Therefore, if the small laser distance measuring device is designed so that space saving is given priority over the distance measuring accuracy, the laser distance measuring device can be arranged in the space immediately above the first electric motor 32.
For example, as shown in FIG. 10, by arranging a small laser distance measuring device 68 on the base 54 of the rotating unit 38, the entire configuration of the optical scanning device 30 including the laser distance measuring device can be reduced in size. Is possible.
Further, even when the small laser distance measuring device 68 designed to save space as described above is adopted, it is possible to stabilize the distance measuring accuracy with the configuration capable of high-speed scanning as in the present invention. Therefore, the overall accuracy in practical use does not deteriorate.

In addition, the optical scanning device of the present invention is not limited to laser light as the scanning light, and light emitted by other light emitting elements may be employed.

Claims

A first electric motor;
A rotating part that is rotatable about the vertical direction as an axis by the rotational driving force of the first electric motor;
A main reflector that is attached to the rotating unit, rotates together with the rotating unit about the vertical direction as an axis, irradiates the scanning light toward the object, and receives reflected light from the object;
An optical scanning device comprising: a second electric motor that is attached to the rotating unit and rotates the main reflecting mirror about an axis that has a predetermined angle with respect to a horizontal plane.
The reflecting surface of the main reflecting mirror has a predetermined angle other than a right angle or a parallel angle with respect to a rotation axis by the second electric motor,
2. The optical scanning device according to claim 1, wherein scanning light is incident on the reflecting surface of the main reflecting mirror in parallel with the rotation axis of the second electric motor.
The main reflector is
A rod mirror having a reflecting surface in which a tip of a cylindrical rod extending along a rotation axis by the second electric motor is formed at a predetermined angle other than an angle perpendicular to or parallel to the rotation axis by the second electric motor. The optical scanning device according to claim 2, wherein:
The rotation axis of the second electric motor passes through the center of the reflecting surface of the main reflecting mirror, and the scanning light is incident on the center of the reflecting surface of the reflecting mirror. The optical scanning device described.
5. The optical scanning device according to claim 1, wherein a predetermined angle with respect to a horizontal plane of the main reflector is adjustable.
The rotating shaft of the first electric motor is a hollow rotating shaft having a hollow inside,
The sub-reflector is provided directly above the hollow rotary shaft so as to reflect the scanning light irradiated from below through the hollow rotary shaft toward the reflecting mirror. 6. The optical scanning device according to any one of items 5.
The subreflector is
The optical scanning device according to claim 6, wherein the optical scanning device is attached to the rotating unit and rotates together with the rotating unit about a vertical direction as an axis.