JP2018132482A - Laser distance measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser distance measuring device that performs distance measurement for a hemispherical range.SOLUTION: The laser distance measuring device comprises: a collimator lens converting output light outputted from a light source into parallel light and emit it; an emission part receiving the parallel light from the collimator lens and deflecting and emitting the received parallel light; a deflection part deflecting and emitting the parallel light so as to change the emission direction of the parallel light emitted by the emission part in an in-plane direction of a plane orthogonal to the incident direction of the parallel light, and deflecting reflected light reflected by an object into a direction which the parallel light comes in and emit it; a condenser lens condensing the reflected light emitted from the deflection part relative to a detector; a rotation mechanism rotating, with a vertical direction as rotation axis, an optical system including the light source, the collimator lens, the emission part, the deflection part, the condenser lens, and the detector; and a measurement part measuring a distance to the object reflecting the parallel light based on reflected light detected by the detector.SELECTED DRAWING: Figure 1A

Description

  The present invention relates to a laser distance measuring device.

  2. Description of the Related Art Conventionally, a technique for emitting a laser beam to an object and measuring a distance to the object based on reflected light reflected by the object is known. A laser distance measuring device to which such a technique is applied is also called LiDAR (Light Detection and Ranging), and is applied to various fields. The object is a measurement object that exists around the laser distance measuring device, and includes all objects that are irradiated with laser light emitted from the light source and reflect the laser light to the laser distance measuring device.

JP 2014-109686 A

  Here, in the laser distance measuring apparatus described above, three-dimensional LiDAR is known that performs three-dimensional distance measurement by two-dimensionally scanning laser light. In such a laser distance measuring apparatus, for example, a mirror that is swung in the vertical direction reflects the laser light emitted from the light source, thereby scanning the laser light in the vertical direction. The same mirror receives the reflected light reflected by the object and reflects it in the direction of the photodetector, thereby detecting the reflected light. Further, in a laser distance measuring apparatus that performs three-dimensional distance measurement, the laser beam is further scanned in the horizontal direction by rotating the structure itself that scans the laser beam in the vertical direction around the vertical direction. Accordingly, the laser distance measuring device performs a three-dimensional distance measurement by scanning the laser beam two-dimensionally.

  A laser distance measuring device that performs such three-dimensional distance measurement has a vertical scanning angle of about 20 ° to 40 ° due to structural limitations. Therefore, in this laser distance measuring device, the range in which distance measurement can be performed is limited to the range included in the scanning angle, and the object is outside the scanning angle range (for example, upward or downward direction of the device). Cannot measure distance.

  This invention is made | formed in view of the above, Comprising: It aims at providing the laser distance measuring device which can perform distance measurement about a hemispherical range.

  In order to solve the above-described problems and achieve the object, a laser distance measuring device according to an aspect of the present invention includes a collimating lens that emits output light output from a light source as parallel light, and the collimating lens An exit part that emits parallel light and deflects and emits the incident parallel light, and an in-plane direction of a plane in which the exit direction of the parallel light emitted by the exit part is orthogonal to the incident direction of the parallel light And deflecting the parallel light so that the reflected light is reflected, and deflecting the reflected light reflected by the object in the direction in which the parallel light is incident, and the reflection emitted from the deflecting part. A condensing lens for condensing light on a detector, the light source, the collimating lens, the emitting unit, the deflecting unit, the condensing lens, and the detection with the vertical direction as a rotation axis Vessel Comprising a rotating mechanism for rotating the free optical system, on the basis of the detected the reflected light by the detector, and a measuring unit for measuring a distance to an object that reflects the collimated light. The light source and the collimating lens are disposed outside an optical path where the reflected light is condensed on the detector by the condenser lens. The exit portion is disposed on the optical path of the parallel light in the plane of the condenser lens, is supported by the condenser lens, and converts the parallel light incident from the collimator lens into a main plane of the condenser lens. It is deflected in a direction perpendicular to the direction.

  According to one embodiment of the present invention, distance measurement can be performed for a hemispherical range.

FIG. 1A is a side view showing the configuration of the laser distance measuring apparatus according to the first embodiment. FIG. 1B is a cross-sectional view showing the configuration of the laser distance measuring apparatus according to the first embodiment. FIG. 2A is a diagram for explaining an example of a wedge mirror according to the first embodiment. FIG. 2B is a diagram illustrating an example of deflection by the wedge mirror according to the first embodiment. FIG. 3 is a block diagram illustrating an example of the configuration of the laser distance measuring apparatus according to the first embodiment. FIG. 4 is a diagram for explaining an example of scanning by the laser distance measuring apparatus according to the first embodiment. FIG. 5 is a diagram for explaining an example of scanning by the laser distance measuring apparatus according to the first embodiment. FIG. 6 is a diagram for explaining an example of scanning by the laser distance measuring apparatus according to the first embodiment. FIG. 7 is a cross-sectional view showing the configuration of the laser distance measuring device according to the first modification. FIG. 8A is a side view showing a configuration of a laser distance measuring device according to Modification 2. FIG. 8B is a cross-sectional view illustrating a configuration of a laser distance measuring device according to Modification 2. FIG. 9 is a side view showing the configuration of the laser distance measuring apparatus according to the second embodiment. FIG. 10A is a diagram for explaining an example of scanning by the laser distance measuring device according to the second embodiment. FIG. 10B is a diagram for explaining an example of scanning by the laser distance measuring device according to the second embodiment.

  Hereinafter, a laser distance measuring device according to an embodiment will be described with reference to the drawings. In addition, the relationship of the dimension of each element in a drawing, the ratio of each element, etc. may differ from reality. Even between the drawings, there are cases in which portions having different dimensional relationships and ratios are included.

(First embodiment)
FIG. 1A is a side view showing the configuration of the laser distance measuring apparatus 100 according to the first embodiment. Here, in FIG. 1A, while showing the side view of the laser distance measuring device 100, the front view of the condensing lens which the laser distance measuring device 100 has on the left side of a side view is shown. FIG. 1B is a cross-sectional view showing the configuration of the laser distance measuring apparatus 100 according to the first embodiment. Here, in FIG. 1B, the cross section of the laser distance measuring device 100 is shown. As shown in FIG. 1A, the laser distance measuring device 100 includes a light source 110a, a light emitting circuit board 110b, a collimator lens 120, a wedge prism 130, a wedge mirror 140, a first motor 150, and a condenser lens 160. , A photodetector 170a, a light receiving circuit board 170b, a control circuit board 180, a second motor 191 and a fixing portion 192. The wedge mirror 140 is, for example, a mirror having a shape in which a surface obtained by cutting a cylinder at an oblique angle of 45 ° is a reflection surface. That is, the wedge mirror 140 is a mirror having a reflecting surface inclined with respect to incident light. Hereinafter, the case where the wedge mirror 140 is used will be described as an example. However, the embodiment is not limited to this example. For example, the mirror is disposed obliquely (for example, inclined at 45 °). Thus, the reflective surface may be inclined with respect to the incident light.

  1A and 1B do not show the casing of the laser distance measuring device 100, but in reality, each component is housed in a casing (not shown). Here, the housing that houses each component is configured to transmit the light emitted from the wedge mirror 140 and the light reflected by the object. For example, the entire housing is formed of a member that transmits light. Alternatively, the housing has a window that transmits light along the direction of light emitted from the wedge mirror 140. In addition, the wedge prism 130 is an example of an emission unit, and the wedge mirror 140 is an example of a deflection unit.

  The laser distance measuring device 100 causes output light (for example, laser light) output from the light source 110 a to be incident on the wedge mirror 140 via the wedge prism 130 as parallel light by the collimator lens 120. The wedge mirror 140 emits the parallel light incident through the wedge prism 130 to the target space while deflecting it along the vertical plane, and reflects the reflected light reflected by the object in the target space toward the condenser lens 160. To deflect. The condensing lens 160 condenses the reflected light incident from the wedge mirror 140 on the photodetector 170a, and the photodetector 170a detects the collected reflected light. In the laser distance measuring apparatus 100, the distance to the object is measured based on the reflected light detected by the photodetector 170a.

  Here, in the laser distance measuring device 100, an output unit that outputs parallel light to the wedge mirror 140 is supported by the condenser lens 160. For example, the wedge prism 130 is disposed inside the condenser lens 160 so that the entire periphery of the wedge prism 130 is surrounded by the condenser lens 160. Details of the laser distance measuring apparatus 100 will be described below. Hereinafter, the reflected light reflected by the object and returned to the laser distance measuring apparatus 100 is also referred to as return light.

  The light source 110a is a light emitting element such as a laser diode (LD), and outputs light (for example, a laser) to the collimating lens 120 in accordance with a drive signal from a drive circuit disposed on the light emitting circuit board 110b. Light). Here, the light source 110a is disposed on the light emitting circuit board 110b so that the optical axis of the laser light is output in the horizontal direction and the optical axis is aligned with the optical axis of the laser light emitted from the collimating lens 120. Has been. In addition, as shown in FIG. 1B, the light source 110a is disposed outside the optical path where the reflected light is collected by the condenser lens 160 onto the photodetector 170a.

  The light emitting circuit board 110b is provided with a driving circuit that outputs laser light from the light source 110a, and outputs a driving signal to the light source 110a in accordance with a control signal from the control circuit board 180. Here, the light emitting circuit board 110b is arranged on the control circuit board 180 so that the longitudinal direction is parallel to the vertical direction, and the light source 110a is arranged at the upper end in the longitudinal direction.

  The collimating lens 120 is arranged so that the light incident surface faces the light emitting surface of the light source 110a, and emits the laser light output from the light source 110a to the wedge prism 130 as parallel light. Here, the collimating lens 120 is disposed on the control circuit board 180 so that the optical axis of the parallel light emitted to the wedge prism 130 is aligned with the optical axis of the laser light emitted from the light source 110a. Further, as shown in FIG. 1B, the collimating lens 120 is disposed outside the optical path where the reflected light is condensed on the photodetector 170 a by the condenser lens 160.

  The wedge prism 130 receives parallel light from the collimator lens 120, deflects the incident parallel light, and emits the deflected light. Specifically, the wedge prism 130 deflects the parallel light incident from the collimator lens 120 in a direction orthogonal to the main plane of the condenser lens 160 and emits the light to the wedge mirror 140. That is, the wedge prism 130 deflects parallel light in the direction of the optical axis of the condenser lens 160. Here, the main plane of the condenser lens 160 is a surface orthogonal to the optical axis of the condenser lens 160.

  Here, the wedge prism 130 is disposed on the optical path of parallel light in the plane of the condenser lens 160 and is supported by the condenser lens 160. That is, as shown in FIGS. 1A and 1B, the wedge prism 130 is embedded in a through hole provided in the condenser lens 160 and deflects the parallel light incident from the collimator lens 120 disposed inside the apparatus. Then, the light is emitted to the wedge mirror 140. For example, the wedge prism 130 is embedded in the center of the condenser lens 160 as shown in the front view of FIG. 1A.

  The wedge mirror 140 deflects and emits parallel light so that the emission direction of the parallel light emitted by the wedge prism 130 changes in the in-plane direction of the plane orthogonal to the incident direction of the parallel light. The reflected light reflected by the object is deflected and emitted in the direction in which the parallel light is incident. For example, the wedge mirror 140 reflects the parallel light in a direction orthogonal to the incident direction and rotates about the incident direction of the parallel light as a rotation axis, so that the parallel light emission direction is orthogonal to the incident direction of the parallel light. The parallel light is deflected and emitted so as to change in the in-plane direction.

  FIG. 2A is a diagram for explaining an example of the wedge mirror 140 according to the first embodiment. FIG. 2B is a diagram illustrating an example of deflection by the wedge mirror 140 according to the first embodiment. For example, as shown in FIG. 2A, the wedge mirror 140 is formed so that a surface obtained by cutting a cylinder at 45 ° becomes a reflection surface 141. As shown in FIG. 2B, the wedge mirror 140 is disposed so that the reflection surface 141 faces the emission side surface of the wedge prism 130 (the light reception side surface of the condensing lens 160). Here, the wedge mirror 140 is disposed on the control circuit board 180 so that the center position of the reflecting surface 141 in the vertical direction matches the center position of the wedge prism 130. Further, the wedge mirror 140 is disposed on the control circuit board 180 so that the center position of the reflection surface 141 in the horizontal direction matches the position of the rotation axis of the control circuit board 180.

  In the wedge mirror 140, the central axis of the surface of the cylinder on which the reflecting surface 141 is not formed is coupled to the rotation shaft of the first motor 150, and the driving force of the first motor is transmitted via the rotation shaft. Rotate. That is, the wedge mirror 140 reflects the parallel light emitted from the wedge prism 130 and the return light reflected by the object by the reflecting surface 141 while rotating about the central axis. Thereby, as shown in FIG. 2B, the wedge mirror 140 deflects the parallel light incident from the wedge prism 130 so that the emission direction changes in the in-plane direction of the plane orthogonal to the incident direction of the parallel light. To the target space.

  Further, the wedge mirror 140 receives the return light reflected by the object in the target space by the reflection surface 141 and reflects it toward the condenser lens 160. That is, the wedge mirror 140 receives the return light from each direction of the parallel light emitted by changing the emission direction to the in-plane direction of the plane orthogonal to the incident direction of the parallel light, and Reflect in the direction.

  Returning to FIGS. 1A and 1B, the first motor 150 is disposed on the control circuit board 180 so that the rotation axis is in the horizontal direction, and the rotation axis is coupled to the central axis of the wedge mirror 140. The first motor 150 rotates the wedge shaft 140 supported by the rotation shaft by rotating the rotation shaft based on the drive signal output from the drive circuit.

  The condensing lens 160 condenses the return light, which is the parallel light emitted by the wedge mirror 140 and reflected by the object, on the photodetector 170a. For example, the condensing lens 160 is a plano-convex lens, a Fresnel lens, or the like. Here, in the first embodiment, an example in which a Fresnel lens is used as the condenser lens 160 is shown. When a Fresnel lens is used as the condenser lens 160, the area can be increased while the thickness of the condenser lens 160 remains constant. The condenser lens 160 has a through hole at the center, and the wedge prism 130 is embedded in the through hole. That is, the condensing lens 160 supports the wedge prism 130 by the through hole.

  The photodetector 170 a detects the return light collected by the condenser lens 160. For example, the photodetector 170a is a photomultiplier tube (PMT), a photoconductive element such as CdS or PbS that utilizes a change in electrical resistance caused by light irradiation, or a photovoltaic photon that utilizes a pn junction of a semiconductor. It is a diode (Photo Diode: PD). Examples of the photodiode include a PN photodiode, a PIN photodiode, and an avalanche photodiode.

  The light receiving circuit board 170b is provided with an amplifier circuit and the like, amplifies the return light detected by the photodetector 170a, and outputs the amplified light to the control circuit board 180. Here, the light receiving circuit board 170b is disposed on the control circuit board 180 so that the longitudinal direction is parallel to the vertical direction. In the light receiving circuit board 170b, the photodetector 170a is disposed so that the center of the photodetector 170a is disposed at a position aligned with the height of the optical axis of the laser light output from the light source 110a.

  The control circuit board 180 includes an optical system including a light source 110a, a collimator lens 120, a wedge prism 130, a wedge mirror 140, a condenser lens 160, and a photodetector 170a, a light emitting circuit board 110b, and a light receiving circuit. A circuit that supports the substrate 170b and the first motor 150 and performs overall control of the laser distance measuring apparatus 100 is disposed. For example, the control circuit board 180 controls the light emission circuit board 110b to control the output of the laser light from the light source 110a. In addition, the control circuit board 180 is provided with various circuits for measuring the distance to the object reflecting the laser light based on the return light detected by the photodetector 170a.

  For example, the control circuit board 180 is provided with a circuit for measuring distance of the TOF (Time of Flight) method, a circuit for measuring distance of the phase difference method, or the like. When performing the distance measurement of the TOF method, the control circuit board 180 is provided with a circuit for calculating the distance from the delay time between the signal based on the laser light and the signal based on the return light. On the other hand, when performing phase difference distance measurement, the control circuit board 180 calculates a phase difference between the signal based on the laser light and the signal based on the return light, and calculates a distance from the calculated phase difference. Is disposed.

  And the control circuit board 180 is rotated by the rotation mechanism mentioned later in the state which supported each structure. For example, the control circuit board 180 is formed of a circular board, and the above-described components are placed on the board. The control circuit board 180 has the rotation axis of the second motor 191 coupled to the center of the board in the horizontal direction, and the driving force of the second motor is transmitted through the rotation axis, so that the vertical direction is the rotation axis. Rotate. That is, the control circuit board 180 includes the light source 110a, the light emitting circuit board 110b, the collimating lens 120, the wedge prism 130, the wedge mirror 140, the first motor 150, the condenser lens 160, and the photodetector 170a. The light receiving circuit board 170b is supported, and is supported rotatably about the rotation axis of the second motor 191.

  As described above, the laser distance measuring device 100 has a rotation mechanism that rotates the control circuit board 180. For example, the laser distance measuring device 100 includes a second motor 191 and a fixing unit 192 as a rotation mechanism.

  The second motor 191 rotates the control shaft 180 supported by the rotation shaft by rotating the rotation shaft based on the drive signal output from the drive circuit. The fixing unit 192 includes the second motor 191 and supports the entire laser distance measuring apparatus 100.

  As described above, in the laser distance measuring apparatus 100, the wedge mirror 140 emits the parallel light emitted from the wedge prism 130 to the target space while changing the emission direction in the in-plane direction of the plane orthogonal to the incident direction. , It is possible to scan with respect to each direction in the plane perpendicular to the incident direction. Further, the laser distance measuring apparatus 100 realizes horizontal scanning by rotating the optical system including the wedge mirror 140 described above about the vertical direction. That is, the laser distance measuring device 100 can perform scanning along a plane (vertical plane) orthogonal to the incident direction while rotating 360 °, and can scan a spherical range. In the laser distance measuring apparatus 100 shown in FIG. 1A, the control circuit board 180 scans the upper direction of the apparatus in a hemispherical shape in order to shield the parallel light emitted from the wedge mirror 140.

  Further, in the laser distance measuring device 100, the center of the wedge prism 130 and the center of the condenser lens 160 are made to coincide. Accordingly, the return light efficiently returns to the condenser lens 160, and the return light can be efficiently collected by the condenser lens 160 regardless of the distance to the object.

  Furthermore, by using the wedge prism 130 as the emitting portion, the degree of freedom of arrangement of the light source 110a and the collimating lens 120 can be improved, and the collection efficiency of return light can be improved. That is, in the laser distance measuring device 100, the light source 110a and the collimating lens 120 can be disposed outside the space sandwiched between the condenser lens 160 and the photodetector 170a. In other words, the light source 110a and the collimating lens 120 can be arranged outside the optical path of the return light condensed on the photodetector 170a by the condensing lens 160, and the condensing is inhibited by the light source 110a and the collimating lens 120. Can be suppressed. For example, as shown in FIG. 1B, the light source 110a and the collimating lens 120 are disposed outside the space formed by connecting the end of the condenser lens 160 and the end of the photodetector 170a.

  Furthermore, by using the wedge prism 130 as the emission part, the degree of freedom of arrangement of the emission part can be improved, and the collection efficiency of the return light can be improved. That is, by using the wedge prism 130 as the emitting portion, the laser beam can be deflected at an arbitrary angle. For example, as shown in FIGS. 1A and 1B, the wedge prism 130 is placed at the center of the condenser lens 160. By arranging, return light can be collected efficiently.

  In addition, by using the wedge prism 130 as the emitting portion, the degree of freedom of arrangement of the light source 110a, the collimating lens 120, and the wedge prism 130 can be improved. Therefore, the shape of the wedge prism 130 is determined according to the arrangement state of each member. That is, the shape and number of wedge prisms 130 used are determined according to the angle at which the parallel light emitted from the collimator lens 120 is deflected. Furthermore, the shape and the number of sheets may be determined in consideration of the material of the wedge prism 130.

  In addition, embodiment mentioned above is an example to the last, and embodiment is not limited to this. For example, in the above-described embodiment, the case where the wedge prism 130 is arranged at the center of the condenser lens 160 has been described as an example. However, the embodiment is not limited to this, and, for example, the wedge prism 130 can be disposed at any position as long as the entire periphery is disposed so as to be surrounded by the condenser lens.

  Next, a distance measurement process performed by the laser distance measuring apparatus 100 will be described with reference to FIG. FIG. 3 is a block diagram illustrating an example of the configuration of the laser distance measuring apparatus 100 according to the first embodiment. In FIG. 3, a case where distance measurement by the TOF method is performed will be described as an example. As shown in FIG. 3, the light receiving circuit board 170b of the laser distance measuring device 100 includes a transimpedance amplifier 171b and an amplifier circuit 172b. The control circuit board 180 includes a TDC (Time to Digital Converter) circuit 181, a signal processing circuit 182, and a control circuit 183. The signal processing circuit 182 is also described as a measurement unit. The laser distance measuring device 100 includes a drive circuit 151 and a drive circuit 193. The drive circuit 151 is controlled by a control circuit (not shown) and drives the first motor 150 at a predetermined speed. The drive circuit 193 is controlled by a control circuit (not shown) and drives the second motor 191 at a predetermined speed.

  The control circuit 183 synchronizes the drive of the first motor 150 and the drive of the second motor 190, thereby generating a pulse signal and an electrical signal of the return light for each rotation angle of the wedge mirror 140 and each rotation angle of the control circuit board 180. Can be detected. The drive circuit 111 b generates a drive signal in synchronization with the pulse signal from the control circuit 183 and outputs the drive signal to the light source 110 a, so that the laser from the light source 110 a and the rotation angle of the control circuit board 180 are output from the light source 110 a. Light is emitted in pulses.

  The transimpedance amplifier 171b converts the current generated by the photodetector 170a based on the return light into a voltage and outputs the voltage to the amplifier circuit 172b. The amplifier circuit 172b amplifies the electrical signal of the return light detected by the photodetector 170a to a level at which signal analysis is possible and outputs the amplified signal to the TDC circuit 181. Specifically, the amplification circuit 172b receives the electric signal converted by the transimpedance amplifier 171b and amplifies the input electric signal.

  The TDC circuit 181 outputs a digital signal indicating a time difference between the pulse signal input from the control circuit 183 and the electrical signal input from the amplifier circuit 182b to the signal processing circuit 182. Specifically, the TDC circuit 181 includes a pulse signal for each rotation angle of the wedge mirror 140 and the control circuit board 180 input from the control circuit 183, and a rotation angle of the wedge mirror 140 input from the amplifier circuit 172b. And each digital signal which shows the time difference with the electric signal for every rotation angle of the control circuit board 180 is output to the signal processing circuit 182. The signal processing circuit 182 calculates the distance to the object from the time corresponding to the digital signal input from the TDC circuit 181 and the speed of light.

  The laser distance measuring device 100 according to the first embodiment has been described above. Hereinafter, an example of scanning by the laser distance measuring apparatus 100 will be described with reference to FIGS. 4-6 is a figure for demonstrating an example of the scanning by the laser distance measuring device 100 which concerns on 1st Embodiment. Here, the following description will be made with reference to FIG. 4 in which polar coordinates (r, θ, φ) are added to three-dimensional orthogonal coordinates (x, y, z). Assuming that the z direction in the three-dimensional orthogonal coordinates (x, y, z) is the vertical direction and the xy plane is the horizontal plane, the horizontal scanning by the rotation of the control circuit board 180 of the laser distance measuring device 100 uses the point on the xy plane as the origin. The rotation is an angle “φ” that rotates around, and scanning by the rotation of the wedge mirror 140 placed on the control circuit board 180 is an angle “θ”.

  The relationship between the three-dimensional orthogonal coordinates and the polar coordinates is generally given by the following equation (1). That is, as shown in the following formula (1), “x”, “y”, and “z” of the three-dimensional orthogonal coordinates are calculated by the spherical radius “r”, the angle “φ”, and the angle “θ” in polar coordinates. can do.

  Here, if the rotation speed of the control circuit board 180 is “150 rpm (2.5 Hz)” and the rotation speed of the wedge mirror 140 is “9000 rpm (150 Hz)”, the relationship between “θ” and “φ” is “θ = 60”. The coordinates of the scanning trajectory when “φ” and the spherical radius “r = 1” are expressed by the following equation (2).

  FIG. 5 shows a scanning trajectory from when scanning is started from the point of “θ = φ = 0” until it returns to “θ = φ = 0” again. For example, the scanning by the laser distance measuring device 100 is a spherical scanning as shown in FIG. 5 by rotating the scanning of the surface orthogonal to the incident direction of the parallel light by “360 °”. Here, when scanning is performed at the above-described number of rotations, the scanning by the wedge mirror 140 reciprocates 60 times while the control circuit board 180 rotates once, and the scanning density becomes “6 ° (360 ° / 60)”. That is, the laser distance measuring apparatus 100 performs scanning with the wedge mirror 140 at “6 °” intervals while the control circuit board 180 is rotating.

  Here, FIG. 6 shows a diagram in which the laser beam is emitted for every “6 °” of the angle “θ” due to the rotation of the wedge mirror 140, and the measurement points when the measurement is performed are superimposed on the scanning locus. In this case, as shown in FIG. 6, the laser distance measuring apparatus 100 measures the distance to the object in the direction indicated by each point indicated on the scanning locus. The signal processing circuit 182 calculates the distance to the object using the above-described equations. In the laser distance measuring device 100, the scanning range changes according to the positional relationship between the wedge mirror 140 and the control circuit board 180. As described above, the laser distance measuring apparatus 100 scans in the in-plane direction of the plane orthogonal to the incident direction of the parallel light by rotating the wedge mirror 140 disposed on the upper side of the control circuit board 180. That is, the wedge mirror 140 reflects the parallel light emitted from the wedge prism 130 by the reflecting surface 141 while rotating, so that the parallel light is emitted in the plane perpendicular to the incident direction of the parallel light. Change. Accordingly, the scanning range in which the parallel light emission angle is lower than the horizontal becomes wider as the distance between the reflecting surface 141 and the control circuit board 180 in the wedge mirror 140 increases. In other words, as the distance between the reflecting surface 141 of the wedge mirror 140 and the control circuit board 180 increases, the downward angle at which the reflected parallel light does not hit the control circuit board 180 becomes deeper, and the parallel light is emitted at a more downward angle. Will be able to. For example, in the laser distance measuring apparatus 100, the wedge mirror 140 is formed with a gap with respect to the control circuit board 180 so that an angle downward from the horizontal can be scanned. Note that the laser distance measuring device 100 stops light emission and measurement at an angle at which the parallel light reflected by the wedge mirror 140 strikes the control circuit board 180. As described above, the laser distance measuring device 100 performs laser scanning in a substantially hemispherical shape and enables measurement in a substantially hemispherical range.

(Modification 1)
In the first embodiment described above, the case where the wedge prism 130 is disposed within the surface of the condenser lens 160 has been described as an example. However, the embodiment is not limited to this. For example, the wedge prism 130 may not be disposed within the surface of the condenser lens 160. In such a case, for example, the wedge prism 130 is disposed on the optical path of the parallel light between the condensing lens 160 and the photodetector 170a, and the parallel light incident from the collimating lens 120 is converted into the main light of the condensing lens 160. Deflection in a direction perpendicular to the plane. The condenser lens 160 has a through hole formed on the optical path of the parallel light deflected by the wedge prism 130.

  FIG. 7 is a cross-sectional view illustrating a configuration of a laser distance measuring device 100a according to the first modification. Here, in the laser distance measuring device 100a according to the modified example 1, the position of the wedge prism 130 and the through-holes are formed in the condensing lens 160 as compared with the laser distance measuring device 100 according to the first embodiment. The point is different. Hereinafter, this point will be mainly described.

  As shown in FIG. 7, the wedge prism 130 according to the first modification is disposed on the optical path of the parallel light emitted from the collimating lens 120 between the condenser lens 160 and the photodetector 170a. Then, similarly to the wedge prism 130 according to the first embodiment, the wedge prism 130 according to the first modification deflects the parallel light incident from the collimator lens 120 in a direction orthogonal to the main plane of the condenser lens 160. Then, the light is emitted to the wedge mirror 140. Here, as shown in FIG. 7, the condenser lens 160 according to Modification 1 has a through hole 161 formed on the optical path of the parallel light emitted from the wedge prism 130. Accordingly, the parallel light emitted from the wedge prism 130 passes through the through-hole 161 and enters the wedge mirror 140.

(Modification 2)
In the first embodiment and the first modification described above, the case where the parallel light incident from the collimator lens 120 is deflected in the direction orthogonal to the main plane of the condenser lens 160 using the wedge prism 130 has been described. However, the embodiment is not limited to this, and the wedge prism 130 may not be used. In such a case, for example, the light source 110a is disposed between the condenser lens 160 and the photodetector 170a, and the collimator lens 120 is disposed on the optical path of the output light in the plane of the condenser lens 160. Supported by a condenser lens 160.

  FIG. 8A is a side view showing a configuration of a laser distance measuring device 100b according to Modification 2. Here, in FIG. 8A, while showing the side view of the laser distance measuring device 100b, the front view of the condensing lens which the laser distance measuring device 100b has on the left side of a side view is shown. FIG. 8B is a cross-sectional view illustrating a configuration of a laser distance measuring device 100b according to Modification 2. Here, in FIG. 8B, the cross section of the laser distance measuring device 100b is shown. The laser distance measuring device 100b according to the modified example 2 is different from the laser distance measuring device 100 according to the first embodiment in that the collimating lens 120 is disposed in the plane of the condenser lens 160, and The arrangement of the light source 110a and the light emitting circuit board 110b is different. Hereinafter, this point will be mainly described.

  As shown in FIGS. 8A and 8B, the collimating lens 120 according to the modification 2 is arranged on the optical path of parallel light in the plane of the condenser lens 160 and is supported by the condenser lens 160. The collimator lens 120 is the center in the horizontal direction of the condenser lens 160 and is disposed on the lower side in the vertical direction. Here, the condensing lens 160 and the collimating lens 120 according to Modification 2 can be integrally formed.

  The light source 110a according to Modification 2 is arranged on the light emitting circuit board 110b so that the optical axis of the laser light is output in the horizontal direction and the optical axis is aligned with the optical axis of the laser light emitted from the collimating lens 120. It is arranged. Here, in the laser distance measuring device 100b according to the modified example 2, the light source 110a and the light emitting circuit board 110b are arranged in the space between the condenser lens 160 and the photodetector 170a. Accordingly, the light source 110a and the light emitting circuit board 110b hinder the collection of the return light. Therefore, in the laser distance measuring device 100b according to the second modification, the position of the light emitting circuit board 110b may be arranged at an arbitrary position to reduce the inhibition of the collection of the return light as much as possible.

  For example, the light emitting circuit board 110b is disposed inside the control circuit board 180, the light source 110a is supported by the minimum support portion, and the light emitting circuit board 110b and the light source 110a are connected by wiring. Also good.

  As described above, in the laser distance measuring device 100 according to the first embodiment, the laser distance measuring device 100a according to the first modification example, and the laser distance measuring device 100b according to the second modification example, the wedge mirror 140 has parallel light. The control circuit board 180 on which the wedge mirror 140 is mounted is rotated around the vertical direction as a hemispherical shape by changing the emission direction to an in-plane direction perpendicular to the incident direction of the parallel light. Laser scanning is performed, allowing measurement in the hemispherical range.

(Second Embodiment)
Next, a second embodiment will be described. Hereinafter, the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof may be omitted. In the first embodiment described above, the center position of the reflection surface 141 of the wedge mirror 140 in the horizontal direction is arranged on the control circuit board 180 so as to coincide with the position of the rotation axis of the control circuit board 180. Explained. In the second embodiment, a case where the position of the center of the reflection surface 141 of the wedge mirror 140 in the horizontal direction is different from the position of the rotation axis of the control circuit board 180 will be described.

  FIG. 9 is a side view showing the configuration of the laser distance measuring device 100c according to the second embodiment. Compared with the laser distance measuring device 100 according to the second embodiment, the laser distance measuring device 100c according to the second embodiment includes the positions of the wedge mirror and the first motor on the control circuit board 180, and the signal processing circuit. The processing content by 182 is different. Hereinafter, this point will be mainly described.

  As shown in FIG. 9, the wedge mirror 140 according to the second embodiment is arranged so that the position of the center of the reflection surface 141 in the horizontal direction is different from the position of the rotation axis of the control circuit board 180. That is, in the second embodiment, it is possible to improve the degree of freedom of the arrangement of the wedge mirror 140 and facilitate the design. For example, when the position of the center of the reflecting surface 141 in the horizontal direction is matched with the position of the rotation axis of the control circuit board 180, a design for balancing on the rotating control circuit board 180 is required. However, it is possible to balance the rotating control circuit board 180 by adjusting the position of the wedge mirror 140 by improving the degree of freedom of arrangement of the wedge mirror 140.

  As described above, since the position of the center of the reflecting surface 141 in the horizontal direction is different from the position of the rotation axis of the control circuit board 180, the signal processing circuit 182 according to the second embodiment includes the following: The distance to the object is calculated using Equation (3). Here, “d” in Equation (3) indicates the distance between the center position of the reflective surface 141 and the position of the rotation axis of the control circuit board 180. Moreover, the unit of the angle in Formula (3) is an arc degree method.

  The signal processing circuit 182 calculates “x”, “y”, and “z” of the three-dimensional orthogonal coordinates with the distance “d”, the angle “φ”, and the angle “θ” as shown in Expression (3). .

  Hereinafter, an example of scanning by the laser distance measuring device 100c according to the second embodiment will be described with reference to FIGS. 10A and 10B. 10A and 10B are diagrams for explaining an example of scanning by the laser distance measuring device 100c according to the second embodiment. Here, in FIG. 10A and FIG. 1B, scanning trajectories from when scanning starts from the point of “θ = φ = 0” to when it returns to “θ = φ = 0” are shown. FIG. 10A shows a view when viewing the direction from “x = y = 0, z = 1” to “x = y = z = 0”. FIG. 10B shows a view when FIG. 10A is viewed from an obliquely lateral direction. 10A and 10B show the case where “d” is “1/4” of the spherical radius “r”.

  For example, in the scanning by the laser distance measuring device 100c, even when the position of the center of the reflecting surface 141 in the horizontal direction is different from the position of the rotation axis of the control circuit board 180, as shown in FIGS. 10A and 10B, Spherical scan.

  Here, when the position of the center of the reflecting surface 141 in the horizontal direction is different from the position of the rotation axis of the control circuit board 180, the distance to the measurement object changes according to the rotation. For example, the curve L1 shown in FIGS. 10A and 10B shows the locus of the center position of the reflective surface 141 accompanying the rotation of the control circuit board 180. As shown in FIGS. 10A and 10B, the position of the center of the reflecting surface 141 changes as the control circuit board 180 rotates, so the distance to the measurement object changes according to the rotation. Specifically, the distance to the measurement object is shifted by the following formula (4) in the x direction and the y direction according to the angle “φ”.

  Therefore, the signal processing circuit 182 corrects the distance to the object that reflects the parallel light based on the distance between the center position of the reflection surface 141 of the wedge mirror 140 and the position of the rotation axis of the control circuit board 180. For example, the signal processing circuit 182 performs a process of subtracting the distance represented by Expression (4) from the result calculated by the TOF method according to the angle “φ”. Thereby, the laser distance measuring device 100c can perform accurate distance measurement.

  As described above, also in the laser distance measuring device 100c according to the second embodiment, hemispherical laser scanning is performed to enable measurement of a hemispherical range. Further, in the laser distance measuring device 100c according to the second embodiment, it is possible to easily balance the rotating control circuit board 180 by improving the degree of freedom of the arrangement of the wedge mirror 140.

  Further, the present invention is not limited by the above embodiment. What comprised suitably combining each component mentioned above is also contained in this invention. Further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspect of the present invention is not limited to the above-described embodiment, and various modifications can be made.

100, 100a, 100b, 100c Laser distance measuring device 110a Light source 110b Light emitting circuit board 120 Collimate lens 130 Wedge prism (emission part)
140 wedge mirror (deflection part)
150 First Motor 160 Condensing Lens 170a Photodetector 170b Light-Receiving Circuit Board 180 Control Circuit Board 182 Signal Processing Circuit (Measurement Unit)
191 Second motor 192 Fixed part

Claims (7)

A collimating lens that emits the output light output from the light source as parallel light; and
The parallel light is incident from the collimating lens, and an output part that deflects and emits the incident parallel light;
Reflected light that is emitted by deflecting the parallel light so that the direction of emission of the parallel light emitted by the emission unit changes in an in-plane direction of a plane orthogonal to the incident direction of the parallel light, and reflected by an object A deflecting unit that deflects and emits in the direction in which the parallel light is incident,
A condensing lens for condensing the reflected light emitted from the deflecting unit on a detector;
A rotation mechanism that rotates an optical system including the light source, the collimating lens, the emitting unit, the deflecting unit, the condensing lens, and the detector, with a vertical direction as a rotation axis,
A measurement unit that measures a distance to an object that reflects the parallel light based on the reflected light detected by the detector;
The light source and the collimating lens are disposed outside an optical path where the reflected light is collected on the detector by the condenser lens,
The exit portion is disposed on the optical path of the parallel light in the plane of the condenser lens, is supported by the condenser lens, and converts the parallel light incident from the collimator lens into a main plane of the condenser lens. Laser distance measuring device that deflects in a direction perpendicular to the angle. A collimating lens that emits the output light output from the light source as parallel light; and
The parallel light is incident from the collimating lens, and an output part that deflects and emits the incident parallel light;
Reflected light that is emitted by deflecting the parallel light so that the direction of emission of the parallel light emitted by the emission unit changes in an in-plane direction of a plane orthogonal to the incident direction of the parallel light, and reflected by an object A deflecting unit that deflects and emits in the direction in which the parallel light is incident,
A condensing lens for condensing the reflected light emitted from the deflecting unit on a detector;
A rotation mechanism that rotates an optical system including the light source, the collimating lens, the emitting unit, the deflecting unit, the condensing lens, and the detector, with a vertical direction as a rotation axis,
A measurement unit that measures a distance to an object that reflects the parallel light based on the reflected light detected by the detector;
The light source and the collimating lens are disposed outside an optical path where the reflected light is collected on the detector by the condenser lens,
The emitting portion is disposed on the optical path of the parallel light between the condenser lens and the detector, and the parallel light incident from the collimator lens is orthogonal to the main plane of the condenser lens. Deflect in the direction,
The condensing lens is a laser distance measuring device in which a through hole is formed on an optical path of the parallel light deflected by the emitting unit. A collimating lens that emits the output light output from the light source as parallel light; and
Reflected light that has been deflected and emitted from the collimated lens so that the direction of emission of the parallel light emitted by the collimator lens changes in an in-plane direction of a plane orthogonal to the incident direction of the parallel light, and is reflected by an object A deflecting unit that deflects and emits in the direction in which the parallel light is incident,
A condensing lens for condensing the reflected light emitted from the deflecting unit on a detector;
A rotation mechanism that rotates an optical system including the light source, the collimator lens, the deflection unit, the condenser lens, and the detector, with a vertical direction as a rotation axis,
A measurement unit that measures a distance to an object that reflects the parallel light based on the reflected light detected by the detector;
The light source is disposed between the condenser lens and the detector;
The collimating lens is a laser distance measuring device that is disposed on an optical path of the output light in a plane of the condenser lens and is supported by the condenser lens.   The laser according to claim 1, wherein the deflecting unit is a deflecting mirror that reflects the parallel light in a direction orthogonal to an incident direction and rotates the incident direction of the parallel light as a rotation axis. Distance measuring device.   The laser distance measuring device according to claim 4, wherein a position of a center of a reflection surface of the deflection mirror in a horizontal direction coincides with a position of a rotation axis of the rotation mechanism.   The laser distance measuring device according to claim 4, wherein the position of the center of the reflecting surface of the deflecting mirror in the horizontal direction is different from the position of the rotating shaft of the rotating mechanism.   The said measurement part correct | amends the distance to the object which reflected the said parallel light based on the distance of the position of the center of the reflective surface of the said deflection | deviation mirror, and the position of the rotating shaft of the said rotation mechanism. Laser distance measuring device.