Optical displacement meter

Abstract

Provided is an optical displacement meter capable of accurately acquiring contours at a plurality of positions of a workpiece without providing a conveyor or a linear motion mechanism, while solving problems in terms of dust prevention, safety, and the like during operation. An optical displacement meter (1) is provided with: a light-projecting / light-receiving module (10) that integrally holds a light-projecting unit (11), a light-condensing unit (12), and an image-capturing unit (13) so as to have a Scheimpflug relationship; a motor (20) that integrally rotates the light projection / reception module (10); a housing (40) that accommodates the light projection / reception module (10); and a control unit that controls the motor (20) so as to rotate the light projecting / receiving module (10) in a state in which the Scheimpflug relationship is maintained inside the housing (40), thereby causing the slit light to scan in a direction orthogonal to the X direction.

Description

Technical Field

[0001] The present disclosure relates to an optical displacement meter that measures the displacement of a workpiece using light. Background Art

[0002] As an optical displacement meter, an optical displacement meter configured as follows is known: for example, a slit light extending in the X direction is irradiated to a workpiece, and reflected light reflected by the surface of the workpiece is received, thereby obtaining an XZ cross-sectional profile. By obtaining a plurality of XZ cross-sectional profiles at different positions in the Y direction of the workpiece, data of the three-dimensional shape of the workpiece can be generated. However, in this case, a conveyor for transporting the workpiece in the Y direction, a direct-acting mechanism for moving the displacement meter body relative to the workpiece in the Y direction, and the like are required, which is sometimes difficult to introduce.

[0003] In contrast, there is known a structure in which a light-projecting system for projecting slit light and a light-receiving system for receiving reflected light (collectively referred to as a light-projecting and light-receiving system) are rotatably constructed, such as in Patent Documents 1 and 2, and the light-projecting and light-receiving system is rotated so that the slit light can scan the workpiece in the Y direction.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: European Patent Publication No. 3232152

[0007] Patent Document 2: China Utility Model Registration No. 210664364 Utility Model Content

[0008] Problems to be solved by utility models

[0009] In addition, by rotating the light projecting and receiving system as in Patent Documents 1 and 2, a plurality of cross-sectional profiles at different positions of the workpiece can be obtained without providing equipment such as a conveyor or a linear motion mechanism, which has the advantage of being easy to introduce.

[0010] However, in order to obtain a high-precision contour regardless of the rotation angle of the light-projecting and light-receiving system, it is important to use a so-called Scheimpflug optical system in which the light-receiving surface of the camera unit is tilted relative to the optical axis of the lens so that the depth of field in the Z direction becomes deeper. However, the Scheimpflug optical system is not maintained in Patent Document 1, so it is considered difficult to obtain a high-precision contour.

[0011] In addition, if actual use is considered, in terms of dust prevention and dealing with interference light, it is conceivable to accommodate the light-projecting and light-receiving system in a housing. Not only is it necessary to prevent dust and deal with interference light, but if there is no housing, the rotating light-projecting and light-receiving system will be exposed, which is visually annoying. In addition, safety considerations need to be taken to prevent contact with the rotating light-projecting and light-receiving system. However, neither patent document 1 nor patent document 2 discloses a housing that can accommodate the light-projecting and light-receiving system, so it is believed that various problems such as dust prevention, dealing with interference light, visual annoyance, and safety may arise.

[0012] The present disclosure is completed in view of the above-mentioned problems, and its purpose is to provide an optical displacement meter that allows a light projection and light receiving system that maintains a Scheimpflug optical system to rotate inside a housing, thereby solving problems such as dust prevention and safety during operation, and can obtain the contours of a workpiece at multiple positions with high precision without setting up a conveyor or a direct-acting mechanism.

[0013] Solutions for solving problems

[0014] In order to achieve the above-mentioned purpose, in this method, an optical displacement meter that uses light to measure the displacement of a workpiece can be used as a premise. The optical displacement meter includes: a light-projecting and light-receiving module, which includes a light-projecting part, a light-collecting part, a camera part, and a supporting member, wherein the light-projecting part irradiates a slit light extending in the X direction, the light-collecting part includes a light-receiving lens that collects the reflected light obtained by the workpiece, the camera part receives the light collected by the light-collecting part, and the supporting member integrally maintains the light-projecting part, the light-collecting part, and the camera part in a Scheimpflug relationship in which the light-receiving surface of the camera part is inclined relative to the optical axis of the light-receiving lens; a motor that integrally rotates the light-projecting and light-receiving module; and a housing that accommodates the light-projecting and light-receiving module. The optical displacement meter also includes a control unit that controls the motor to rotate the light-projecting and light-receiving module in the housing while maintaining the Scheimpflug relationship, so that the slit light is scanned in a direction orthogonal to the X direction.

[0015] According to this structure, when the light-emitting and light-receiving module is rotated while the housing is fixed, the slit light extending in the X direction scans the workpiece in a direction orthogonal to the X direction. As a result, there is no need for a conveyor for transporting the workpiece in the Y direction, a direct-acting mechanism for moving the displacement meter body relative to the workpiece in the Y direction, and other equipment, and it is possible to obtain multiple cross-sectional profiles of the workpiece at different rotation angles to generate data on the three-dimensional shape of the workpiece. In addition, the light-emitting and light-receiving module rotates while being accommodated in the housing, so dust prevention and interference light can be achieved, and it is not visually annoying, and the safety of the light-emitting and light-receiving module when rotating is improved.

[0016] In addition, when the light projecting and receiving modules are rotated, the Scheimpflug relationship is always maintained, so that the focal plane formed in the light projection direction of the light projecting unit can be maintained, and thus a high-precision profile can be obtained.

[0017] Preferably, the rotation axis of the light projecting and light receiving module is arranged to be substantially consistent with the center of gravity of the light projecting and light receiving module on a YZ plane orthogonal to the X direction.

[0018] Preferably, the light projecting part and the light focusing part of the light projecting and light receiving module are arranged at intervals from each other in the radial direction of the rotation axis of the light projecting and light receiving module, and the light focusing part is constructed to be heavier than the light projecting part, and a counterweight is provided at a position in the light projecting and light receiving module that is closer to the light projecting part than to the light focusing part, so as to suppress the deviation of the center of gravity position of the light projecting and light receiving module from the rotation axis on the YZ plane orthogonal to the X direction due to the difference in weight of the light projecting part and the light focusing part.

[0019] Preferably, the light-projecting portion includes a light source and a light source housing for accommodating the light source, the light-focusing portion further includes a lens housing for accommodating the light-receiving lens, the light-projecting portion and the light-focusing portion of the light-projecting and light-receiving module are arranged to be spaced apart from each other in the radial direction of the rotation axis of the light-projecting and light-receiving module, and the volume of the light source housing is configured to be smaller than the volume of the lens housing, and the light source housing is composed of a material having a higher density than that of the lens housing, so as to suppress the deviation of the center of gravity position of the light-projecting and light-receiving module from the rotation axis on a YZ plane orthogonal to the X direction caused by the difference in weight between the light-projecting portion and the light-focusing portion.

[0020] Preferably, the light-projecting and light-receiving module also has a reflecting component, which is arranged on the optical path of the light concentrated by the focusing unit, and reflects the concentrated light toward the camera unit, so that the distance from the rotation axis of the light-projecting and light-receiving module to the camera unit is shortened, and the supporting member holds the reflecting component together with the light-projecting unit, the focusing unit and the camera unit in a sham relationship.

[0021] Preferably, the light-projecting and light-receiving module also has a reflecting component, which is arranged on the optical path of the reflected light obtained by the workpiece, and reflects the reflected light toward the focusing part, so that the distance from the rotation axis of the light-projecting and light-receiving module to the focusing part is shortened, and the supporting member holds the reflecting component together with the light-projecting part, the focusing part and the camera part in an integrated manner having the Sham relationship.

[0022] Preferably, the rotation axis of the light projecting and receiving module is arranged between the light projecting unit and the reflecting member when viewed along the rotation axis.

[0023] Preferably, the rotation axis of the light projecting and light receiving module is arranged at a position overlapping with the light focusing unit when viewed along the rotation axis, or is arranged between the light projecting unit and the light focusing unit.

[0024] Preferably, a bearing is further provided, and the bearing supports the rotating shaft of the light projecting and receiving module.

[0025] The bearing supports a moment load generated by a difference in position between a portion of the rotating shaft supported by the bearing and the center of gravity of the light projecting and receiving module.

[0026] Preferably, an optical encoder is also provided, which is used to detect the rotation angle of the rotating shaft of the light-projecting and light-receiving module. The optical encoder is accommodated in a closed space within the shell to prevent foreign matter from entering from outside the shell, and to prevent foreign matter from entering from the space that accommodates the light-projecting and light-receiving module and for the light-projecting and light-receiving module to rotate.

[0027] Preferably, assuming that the light projection and light receiving module is rotated to a first rotation angle, on a YZ plane orthogonal to the X direction, the light projection and light receiving module has a size that contacts the inner wall of the shell, and the rotation angle range of the light projection and light receiving module rotated during measurement is set to a specified angle range smaller than the first rotation angle to avoid contact between the light projection and light receiving module and the inner wall of the shell.

[0028] Preferably, the control unit controls the motor so as to avoid contact between the light projecting and light receiving module and the inner wall of the housing by rotating the light projecting and light receiving module within the predetermined angle range during measurement.

[0029] Preferably, a stopper is provided inside the housing, and the stopper is used to prevent the light projecting and light receiving module from rotating to the first rotation angle outside the specified angle range and contacting the inner wall of the housing.

[0030] Preferably, the housing has a first thickness in the X direction at an end portion on the irradiation direction side of the slit light, and has a second thickness in the X direction at an end portion on the opposite side to the irradiation direction that is smaller than the first thickness.

[0031] Effect of utility model

[0032] As described above, by rotating the light-projecting and light-receiving module having the Scheimpflug relationship while being housed in a housing, the slit light can be scanned in a direction orthogonal to the X direction. This makes it possible to solve problems such as dust prevention and safety during operation while acquiring the contours of the workpiece at multiple positions with high precision without providing a conveyor or a direct-acting mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a diagram for explaining the operation of the optical displacement meter according to the first embodiment of the present invention.

[0034] Figure 2 This is a perspective view of the optical displacement meter according to Embodiment 1 of the present invention as viewed from above.

[0035] Figure 3 This is a perspective view of the optical displacement meter according to Embodiment 1 of the present invention as viewed from below.

[0036] Figure 4 This is a plan view showing the interior of the upper space of the optical displacement meter according to the first embodiment of the present invention.

[0037] Figure 5 It is a top view of the light projecting and receiving module of the optical displacement meter according to the first embodiment of the present invention.

[0038] Figure 6 This is a block diagram showing the structure of the optical displacement meter according to the first embodiment of the present invention.

[0039] Figure 7 yes Figure 2 VII-VII line cross-sectional view.

[0040] Figure 8 yes Figure 2 Cross-sectional view along line VIII-VIII.

[0041] Fig. 9 It is a diagram for explaining the method of displacement measurement.

[0042] Fig.10 is a modification example 1 of implementation example 1 and Figure 5 Quite a picture.

[0043] Fig.11 is a modification example 2 of implementation example 1 and Figure 4 Quite a picture.

[0044] Fig.12 This is a diagram showing the internal structure of the optical displacement meter according to Modification 2 of Embodiment 1 as viewed from below.

[0045] Fig.13 This is the same as the embodiment 2. Figure 2 Quite a picture.

[0046] Fig.14 This is a diagram showing the internal structure of the optical displacement meter according to the second embodiment as viewed from above.

[0047] Fig.15 This is the same as the embodiment 2. Figure 7 Quite a picture.

[0048] Fig.16 A variation of implementation example 2 involves Fig.14 Quite a picture.

[0049] Fig.17 It is a schematic diagram showing the acquisition range of the measurement results in three-dimensional measurement.

[0050] Fig.18 This is the method involved in implementation mode 3. Figure 6 Quite a picture.

[0051] Fig.19 This is a description of the case where the acquisition range of the image sensor is dynamically changed. Fig.17 Quite a picture.

[0052] Fig. 20 It is a figure which shows an example of a setting screen.

[0053] Fig.21 It is a diagram showing an example of a rectangular acquisition range.

[0054] Fig. 22 It is a diagram showing how the YZ coordinates of the acquisition range are converted into V coordinates and a rotation angle.

[0055] Fig.23 It is a diagram showing a state where the rotation angle range is determined.

[0056] Fig.24 It is a schematic diagram of the optical system.

[0057] Fig.25 This is a diagram schematically showing a range when the number of pixels in the V direction is obtained constantly.

[0058] Fig.26 This is a diagram for explaining the case where the number of pixels in the V direction is changed.

[0059] Fig. 27 This is a diagram for explaining the difference in output time that changes when the acquisition range is shifted.

[0060] Fig.28This is a diagram showing a case where the Z-direction height of the acquired range after translation is changed so that the difference in output time is reduced.

[0061] Fig.29 It is a diagram showing an example of a setting screen on which a setting YZ cross-sectional profile is displayed.

[0062] Fig.30 This is a flowchart showing an example of the flow of processing for acquiring range settings.

[0063] Fig.31 The diagram shows an example of a screen showing a light receiving image and a height image.

[0064] Fig.32 This is a flowchart showing an example of the flow of the display processing of the light-receiving image.

[0065] Fig.33 This is a diagram showing a case where the casing is formed into a simple rectangular parallelepiped shape.

[0066] Fig.34 This is a diagram related to the first example in which the thickness of the casing is locally reduced.

[0067] Fig.35 This is a diagram related to the second example in which the thickness of the casing is locally reduced. DETAILED DESCRIPTION

[0068] Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings. In addition, the following description of the preferred embodiments is essentially illustrative and is not intended to limit the present invention, its application or its use.

[0069] (Implementation Method 1)

[0070] Figure 1 This is a diagram for explaining the operation of the optical displacement meter 1 according to the first embodiment of the present invention. The optical displacement meter 1 is an example of a light-section type optical displacement meter that measures the cross-sectional profile of a workpiece W (measurement object) having a height in the Z direction based on the principle of triangulation using slit light S1. In this embodiment, an example of an inspection system S composed of the optical displacement meter 1, the controller 2, and the personal computer PC is described, but the present invention is not limited to this structural example, and for example, the inspection system S may include a PLC (programmable logic controller) or the like.

[0071] When setting the inspection system S before operation, various inspection settings can be performed by, for example, the controller 2 and the personal computer PC. When operating after the settings, the optical displacement meter 1 measures the displacement of the workpiece W at a predetermined timing. Data indicating the measurement results are sent from the optical displacement meter 1 to the controller 2 and the personal computer PC, and inspection based on the inspection settings is performed. Data indicating the measurement results of the optical displacement meter 1, inspection results, etc. can be stored in the controller 2 and the personal computer PC.

[0072] When operating, it is also possible to operate only with the optical displacement meter 1 without using the controller 2 and the personal computer PC. Figure 1 In the following description, the inspection system S including the optical displacement meter 1 is described, but the present invention can also be applied to the case of using only the optical displacement meter 1 or the case of using a system combining the optical displacement meter 1 and a PLC.

[0073] The inspection system S is a system that performs an appearance inspection of the workpiece W online. In the appearance inspection performed online, for example, the appearance inspection of the workpiece W is performed sequentially at a site where a plurality of workpieces W are sequentially transported. Figure 1 The X direction, Y direction, and Z direction of the workpiece W are defined as shown. The X direction and the Y direction are mutually orthogonal when the workpiece W is viewed from above. The Z direction is the height direction of the workpiece W, and is a direction orthogonal to the X direction and the Y direction. The X direction of the workpiece W can also be called the depth direction of the workpiece W, and the Y direction of the workpiece W can be called the width direction of the workpiece W, but this definition is an example, and the definition of the X direction, Y direction, and Z direction of the workpiece W is arbitrary.

[0074] The height data of the workpiece W can be obtained by the optical displacement meter 1, so the appearance inspection includes dimension inspection, shape inspection, defect inspection, etc. based on the height data. The workpiece W is not particularly limited, and various parts, components, devices, instruments, and parts thereof can be listed. The workpiece W can also be called a measurement object. After the workpiece W is transported to the measurable area of ​​the optical displacement meter 1 by a transport device (not shown), the optical displacement meter 1 performs displacement measurement.

[0075] The optical displacement meter 1 is used in a state of being fixed to, for example, a mounting member 5. The mounting member 5 is a part of equipment installed in a factory or the like, and is fixed so as not to move relative to the workpiece W. Therefore, the optical displacement meter 1 does not move relative to the workpiece W. Although the details will be described later, even if the optical displacement meter 1 is fixed to the mounting member 5, the light projecting and receiving module 10 (such as Figure 4The optical displacement meter 1 (as shown) can rotate around an axis parallel to the X direction, so that the slit light S1 extending along the X direction of the workpiece W can be scanned from the light projecting and light receiving module 10 in a direction orthogonal to the X direction of the workpiece W, and the reflected light S2 obtained by being reflected by multiple locations in the Y direction of the surface W1 of the workpiece W is received by the light projecting and light receiving module 10. In this way, when the light projecting and light receiving module 10 is rotated around an axis parallel to the X direction, the slit light S1 can be scanned on the surface W1 of the workpiece W as in the case where the workpiece W or the optical displacement meter 1 is moved linearly. In addition, the optical displacement meter 1 scans the slit light S1 by rotating the light projecting and light receiving module 10, so the scanning direction of the slit light S1 is a direction including the Y direction and orthogonal to the X direction on the YZ plane. In addition, in this specification, "rotation" refers to a reciprocating swinging motion centered on the rotation axis.

[0076] By performing signal processing based on the amount of light received by the reflected light S2, multiple cross-sectional profiles of the workpiece W at different rotation angles can be obtained. Data (height data) of the three-dimensional shape of the workpiece W can be generated based on the obtained cross-sectional profiles. In addition, since the slit light S1 rotates, the cross-sectional profile is not necessarily parallel to the XZ plane.

[0077] By making the light projecting and receiving module 10 disposed inside the optical displacement meter 1 rotatable as described above, a plurality of cross-sectional profiles of the workpiece W at different rotation angles can be obtained without conveying the workpiece W in the Y direction and without moving the optical displacement meter 1 in the Y direction relative to the workpiece W. Therefore, there is no need for a conveyor for conveying the workpiece W, a direct-acting mechanism for moving the optical displacement meter 1 in the Y direction relative to the workpiece W, and the like, and it is easy to introduce an inspection process using the optical displacement meter 1.

[0078] In addition, the workpiece W may be relatively moved relative to the optical displacement meter 1, but multiple cross-sectional profiles may be obtained with the workpiece W stopped during measurement. In addition, the optical displacement meter 1 may be relatively moved relative to the workpiece W, but multiple cross-sectional profiles may be obtained with the optical displacement meter 1 stopped during measurement. The present invention is not limited to a case where the optical displacement meter 1 is completely fixed, and may be supported on the mounting member 5 in a movable manner, or may be mounted on a robot arm and moved to any measurement location.

[0079] Figure 2 This is a perspective view of the optical displacement meter 1 according to the first embodiment of the present invention as viewed from above. Figure 3This is a stereoscopic view of the optical displacement meter 1 according to Embodiment 1 of the present invention as viewed from below. The left-right direction, depth direction, and up-down direction of the optical displacement meter 1 are defined as shown in the respective figures, but this is for the sake of convenience of explanation and does not limit the posture of the optical displacement meter 1 during operation. Figure 1 In the illustrated application mode, the optical displacement meter 1 is disposed above the workpiece W, so that the slit light S1 is irradiated downward and the reflected light S2 is directed upward. In the case of this application mode, the left-right direction of the optical displacement meter 1 corresponds to the Y direction of the workpiece W, the up-down direction of the optical displacement meter 1 corresponds to the X direction of the workpiece W, and the depth direction of the optical displacement meter 1 corresponds to the Z direction of the workpiece W. In addition, the optical displacement meter 1 may be disposed so that the slit light S1 irradiates the workpiece W from the optical displacement meter 1 in the horizontal direction, or the optical displacement meter 1 may be disposed so that the slit light S1 irradiates the workpiece W from the optical displacement meter 1 downward, and the posture of the optical displacement meter 1 when disposed is not particularly limited.

[0080] Figure 4 1 is a diagram showing the internal structure of the optical displacement meter 1. The optical displacement meter 1 includes a light projecting and receiving module 10 (in Figure 5 ), a motor 20 for rotating the light projecting and receiving module 10 (in Figure 7 ), the motor control unit 30 (in Figure 8 ), and a housing 40. The light projecting and receiving module 10, the motor 20, and the motor control unit 30 are accommodated in the housing 40. Figure 6 As shown, in the present embodiment 1, the control unit 3 is composed of a motor control unit 30, a power supply unit 34 (described later), and a signal processing unit 32 (described later). Figure 6 In the figure, for the sake of convenience of explanation, the motor control unit 30 and the signal processing unit 32 are described separately, but the motor control unit 30 and the signal processing unit 32 may be combined.

[0081] The light projecting and receiving module 10 comprises: a light projecting section 11, which irradiates a slit light S1 extending along the X direction; a light focusing section 12, which has a light receiving lens for focusing the reflected light S2 obtained by reflection from the workpiece W; a camera section 13, which receives the light focused by the light focusing section 12; and a supporting member 14, which holds the light projecting section 11, the light focusing section 12 and the camera section 13 as a whole.

[0082] like Figure 6As shown, the light projecting unit 11 includes a laser emitter (light source) 11a, an optical system 11b, a light source housing that accommodates the laser emitter 11a and the optical system 11b, and a light projecting control unit 11c that controls the laser emitter 11a. The laser emitter 11a is controlled by the light projecting control unit 11c to emit a laser of a specified light amount at a specified timing for a specified time. The light emitted from the laser emitter 11a is incident on the optical system 11b. Although not shown in the figure, the optical system 11b is composed of a plurality of lenses including a cylindrical lens, for example, so that the incident laser is expanded into a strip shape and becomes a slit light S1, which is then irradiated onto the workpiece W. The light projecting unit 11 is in a shape that is long in the irradiation direction of the slit light S1.

[0083] The light collecting unit 12 is configured as a lens unit including a plurality of large-diameter light receiving lenses to increase the amount of light received, and the light collecting unit 12 includes a light receiving lens and a lens housing for accommodating the light receiving lens. Since the light collecting unit 12 includes a plurality of such large-diameter lenses, the size is relatively large, so the weight of the light collecting unit 12 is heavier than that of the light projecting unit 11.

[0084] The imaging unit 13 includes an image sensor 13a such as a CMOS (complementary MOS) and an imaging control unit 13b. The image sensor 13a is controlled by the imaging control unit 13b to perform imaging at a predetermined timing. The exposure time of the image sensor 13a during imaging can be controlled by the imaging control unit 13b.

[0085] like Figure 7 , Figure 8 As shown in FIG. 1 , the support member 14 is composed of a flat plate-shaped high-rigidity member, such as a metal plate. Figure 7 As shown, the support member 14 is fixed to the rotating shaft 50 constituting a part of the optical displacement meter 1, and is supported by the housing 40 so as to be rotatable about the rotation center line A as the axis of the rotating shaft 50. The extending direction of the support member 14 is a direction orthogonal to the rotation center line A.

[0086] The light projecting unit 11, the light collecting unit 12, and the image pickup unit 13 are fixed to the upper surface of the supporting member 14. Figure 5 In the top view of the light projecting and receiving module 10 shown, the light projecting unit 11 is fixed to the portion of the support member 14 on the left side of the rotation center line A, and the light focusing unit 12 and the imaging unit 13 are fixed to the opposite side. Thus, the light projecting unit 11 and the light focusing unit 12 are arranged at a distance from each other in the radial direction (Y direction, Z direction) of the rotation axis 50.

[0087] The light projecting part 11 is configured so that the irradiation direction of the slit light S1 is toward the Z direction. The light focusing part 12 is configured on the front side (the workpiece W side) of the support member 14 in such a manner that the optical axis is along the incident direction of the reflected light S2. Therefore, the light projecting part 11 and the light focusing part 12 are both toward the Z direction, but the optical axis of the optical system 11b of the light projecting part 11 and the optical axis of the light focusing part 12 (the optical axis of the light receiving lens) are in a relationship of crossing each other at a position away from the light projecting and light receiving module 10 in the Z direction. The distance between the light projecting part 11 and the light focusing part 12 in the left-right direction, and the relationship between the optical axis of the optical system 11b of the light projecting part 11 and the optical axis of the light focusing part 12 can be changed according to the installation distance of the optical displacement meter 1 relative to the workpiece W, the measurement accuracy, etc., so the example shown in the figure is only an example.

[0088] The longer the distance between the focusing unit 12 and the rotation axis, the greater the moment of inertia of the focusing unit 12 generated by the rotation. When switching the rotation direction of the projection and light receiving module 10, it is necessary to temporarily stop the projection and light receiving module 10. At this time, the greater the moment of inertia, the greater the energy required to decelerate the rotational motion of the projection and light receiving module 10, which results in an increase in the distance and time until the rotational motion stops. Therefore, the projection and light receiving module 10 is also provided with a light receiving side reflection member 15 fixed to the supporting member 14. Thus, not only can the size of the projection and light receiving module 10 be made compact, but also the moment of inertia generated by the rotation is reduced to shorten the measurement interval. The light receiving side reflection member 15 is composed of, for example, a plane mirror, so that the reflected light S2 emitted from the focusing unit 12 is folded back to the projection unit 11 side, thereby shortening the distance between the imaging unit 13 or the focusing unit 12 and the rotation axis 50 of the projection and light receiving module 10 on the YZ plane. The folding direction may also be, for example, the direction toward the center position in the Y direction of the housing 40. The YZ plane is a plane including both a straight line extending in the Y direction and a straight line extending in the Z direction, and is a plane that is orthogonal to the X direction.

[0089] Specifically, the light-receiving side reflective member 15 is positioned at the right end of the portion of the support member 14 that is further rearward than the light-collecting unit 12, and is disposed on the optical path between the imaging unit 13 and the light-collecting unit 12 on the YZ plane, so that the light collected by the light-collecting unit 12 is reflected toward the imaging unit 13. In addition, the rotation axis 50 of the light-projecting and light-receiving module 10 is disposed between the light-receiving side reflective member 15 and the light-projecting unit 11 on the YZ plane.

[0090] The light receiving side reflector 15 can be arranged on the optical path between the imaging unit 13 and the light focusing unit 12 to reflect the light that has been focused by the light focusing unit 12. Therefore, the area of ​​the light receiving side reflector 15 can be reduced. In addition, the position of the light receiving side reflector 15 may not be on the optical path between the imaging unit 13 and the light focusing unit 12, but may be arranged on the optical path between the imaging unit 13 and the light focusing unit 12 as in the modified example 1 described later (in the optical path between the imaging unit 13 and the light focusing unit 12). Fig.10As shown in FIG. 1 , the focusing unit 12 is arranged on the optical path between the light receiving side reflecting member 15 and the imaging unit 13.

[0091] The light-receiving side reflective member 15 protrudes upward from the upper surface of the supporting member 14. In addition, the extending direction of the light-receiving side reflective member 15 is set as the depth direction. The emission direction of the reflected light S2 incident on the light-receiving side reflective member 15 can be set by the setting angle of the light-receiving side reflective member 15 so that the emission direction of the reflected light S2 is toward the light-receiving surface of the image sensor 13a.

[0092] The positional relationship between the image sensor 13a of the camera unit 13 and the optical axis of the focusing unit 12 is set to a Scheimpflug relationship in which the light receiving surface of the image sensor 13a is tilted relative to the optical axis of the focusing unit 12. An optical system that satisfies the Scheimpflug relationship can be called a Scheimpflug optical system. In the present embodiment, the light projecting unit 11, the focusing unit 12, and the camera unit 13 are integrally held on the supporting member 14 in a manner having a Scheimpflug relationship, thereby constituting a light projecting and light receiving module 10. By having a Scheimpflug relationship, the light projecting unit 11 is focused along the light projection axis, so that a focused contour image can be obtained for the reflected light obtained by the slit light being reflected by the workpiece W. Therefore, the measurement accuracy of the three-dimensional shape data of the workpiece W is improved, and a high-precision contour can be obtained.

[0093] Even when the light projecting and receiving module 10 is rotated around the rotation center line A, the relative positional relationship among the light projecting unit 11, the light focusing unit 12, the imaging unit 13 and the light receiving side reflective member 15 does not change. Therefore, regardless of the rotation angle of the light projecting and receiving module 10, the Scheimpflug relationship is maintained.

[0094] The imaging unit 13 includes a cover glass 13c. The cover glass 13c is formed to cover the light receiving surface of the image sensor 13a and is fixed to the image sensor 13a. The cover glass 13c is composed of a light-transmitting member having a property of transmitting the reflected light S2 emitted from the light-receiving side reflection member 15. The reflected light S2 that has passed through the cover glass 13c forms an image on the light receiving surface of the image sensor 13a.

[0095] The rotation axis 50 of the light projecting and light receiving module 10 is configured to be substantially consistent with the center of gravity position of the light projecting and light receiving module 10 on the YZ plane. That is, in the light projecting and light receiving module 10, the light projecting unit 11, the light focusing unit 12, the camera unit 13, and the light receiving side reflective member 15 are included in the light projecting and light receiving module 10, and when the center of gravity position of the light projecting and light receiving module 10 is measured or calculated in a state where the light projecting unit 11, the light focusing unit 12, the camera unit 13, and the light receiving side reflective member 15 are fixed to the support member 14, the center of gravity position of the light projecting and light receiving module 10 is substantially consistent with the rotation center line A. In other words, the position of the rotation axis 50 in the Y direction and the Z direction relative to the support member 14 is set in such a manner that the center of gravity position of the light projecting and light receiving module 10 becomes the rotation center. The support member 14 is fixed to the rotation axis 50 by a plurality of joint members (not shown) and the like, and the support member 14 and the rotation axis 50 do not rotate relative to each other.

[0096] By making the center of gravity position of the light-projecting and light-receiving module 10 roughly coincide with the rotation center line A, the moment of inertia of the light-projecting and light-receiving module 10 caused by rotation is reduced, and the load of the motor 20 caused by, for example, vibration is suppressed, and the decrease in the rotation speed of the light-projecting and light-receiving module 10 is also suppressed. The center of gravity position of the light-projecting and light-receiving module 10 may not be strictly consistent with the rotation center line A, as long as the deviation is within the allowable degree of manufacturing tolerance. In addition, even if the center of gravity position of the light-projecting and light-receiving module 10 deviates slightly from the rotation center line A, it can be regarded as substantially consistent. For example, as long as the moment of inertia of the light-projecting and light-receiving module 10 can be sufficiently reduced, the load of the motor 20 caused by vibration is sufficiently suppressed, and the decrease in the rotation speed of the light-projecting and light-receiving module 10 can be suppressed, so as long as this effect can be achieved, a slight deviation of the center of gravity position of the light-projecting and light-receiving module 10 from the rotation center line A is allowed, and the two can be said to be roughly consistent.

[0097] As described above, the weight increases due to the enlarged diameter of the light-collecting unit 12. Therefore, it is conceivable that the center of gravity of the light-emitting and light-receiving module 10 may be too close to the light-collecting unit 12, making it difficult to design the center of gravity close to the rotation center line A. Figure 5 As shown by the virtual line in FIG. 1 , a counterweight 16 can be provided at a position on the light-projecting unit 11 side of the light-projecting and light-receiving module 10. Thus, the center of gravity of the light-projecting and light-receiving module 10 can be positioned at the middle of the light-projecting unit 11 and the light-focusing unit 12. The counterweight 16 is arranged at a position on the opposite side of the light-focusing unit 12 across the rotation center line A. The counterweight 16 can be fixed to the supporting member 14 or to the light-projecting unit 11. The number of the counterweights 16 is not limited to one, but may be multiple.

[0098] The closer the rotation axis of the light-projecting and light-receiving module 10 is to the center of gravity, the more stable the rotation can be and the more the load on the rotation axis 50 can be suppressed. However, it is conceivable that the weight of the light-projecting unit 11 and the light-focusing unit 12 are different. With this structure, a counterweight is provided at a position in the light-projecting and light-receiving module 10 that is closer to the light-projecting unit 11 than to the light-focusing unit 12, so that the deviation between the center of gravity of the light-projecting and light-receiving module 10 and the rotation axis 50 caused by the weight difference can be suppressed, thereby stabilizing the rotation and suppressing the load on the rotation axis 50.

[0099] It is also possible not to provide the counterweight 16, but to set the material of the light source housing of the projecting part 11 to a material with a higher density than the material of the lens housing of the focusing part 12. For example, the supporting member 14 and the lens housing with a large volume can be formed of a relatively low-density material such as aluminum, and the light source housing can be formed of a relatively high-density material such as zinc and stainless steel (SUS). In this way, the projecting part 11 can be made heavy, so the center of gravity of the projecting and light-receiving module 10 can be positioned in the middle of the projecting part 11 and the light-receiving part 12. In addition, the material of the housing of the projecting part 11 can be set to a material with a higher density than the material of the housing of the light-receiving part 12, and the counterweight 16 can be provided at a position on the projecting part 11 side of the projecting part 11 in the projecting and light-receiving module 10. In addition, the volume of the light source housing is configured to be smaller than the volume of the lens housing.

[0100] like Figure 7 As shown, the housing 40 is a member for accommodating the light projecting and receiving module 10, the motor 20, and the motor control unit 30, and has a two-stage structure. That is, the housing 40 has an upper housing structure 41 constituting the upper part, and a lower housing structure 42 constituting the lower part. In addition, the two-stage structure can also be called a two-layer structure, in which case the upper housing structure 41 is the first layer, and the lower housing structure 42 is the second layer.

[0101] The upper shell structure 41 and the lower shell structure 42 may be an integral body or may be formed of different components. In this embodiment, a case where the upper shell structure 41 and the lower shell structure 42 are formed of different components is described. In this case, for example, the upper shell structure 41 and the lower shell structure 42 may be combined using a joining member (not shown) to form the shell 40.

[0102] like Figure 7 As shown, the upper housing structure 41 has an upper peripheral wall 43 and an upper wall 44. The upper wall 44 extends along the YZ plane. The upper peripheral wall 43 extends from the peripheral edge of the upper wall 44 toward the lower housing structure 42. The space formed inside the upper housing structure 41 is an upper space R1. The upper space R1 is closed by the lower housing structure 42, and the upper space R1 is sealed.

[0103] like Figure 2 and Figure 4 As shown in FIG. 1 , a light-projecting window 43a and a light-receiving window 43b are provided at the front side of the upper peripheral wall portion 43. The light-projecting window 43a and the light-receiving window 43b are composed of light-transmitting components. Figure 4 As shown, the light projection window 43a is arranged to face the surface of the light projection unit 11 that irradiates the slit light S1. The size and position of the light projection window 43a are set so that the slit light S1 can be irradiated from the light projection window 43a even if the light projection and light receiving module 10 rotates as long as the rotation angle of the light projection and light receiving module 10 is within a predetermined angle range described later.

[0104] In addition, the light receiving window 43b is arranged to face the light incident surface of the light focusing unit 12. The size and position of the light receiving window 43b are set so that the reflected light S2 can be incident on the light focusing unit 12 from the light receiving window 43b even if the light projecting and light receiving module 10 rotates, as long as the rotation angle of the light projecting and light receiving module 10 is within a predetermined angle range described later.

[0105] like Figure 7 As shown, the lower shell structure 42 has a substrate portion 45, a lower peripheral wall portion 46 extending downward from the substrate portion 45, and a cover member 47. The substrate portion 45 extends along the YZ plane and is a portion that closes the lower open portion of the upper shell structure 41. The cover member 47 is mounted on the lower end portion of the lower peripheral wall portion 46. The space formed inside the lower shell structure 42 is the lower space R2. The lower space R2 is sealed by the cover member 47. In short, the shell 40 has a structure that seals the interior. The sealed structure refers to a structure that suppresses external dust and garbage from invading the interior of the shell 40, for example, it can be called a dust-proof structure. In addition, the shell 40 may not be completely sealed, for example, there may be a gap through which air can slightly enter and exit.

[0106] like Figure 3 and Figure 7 As also shown in the figure, recesses 46a are formed on the left and right sides of the lower peripheral wall portion 46 of the lower shell structure portion 42. When observed along the rotation axis of the light projecting and light receiving module 10, the width of the upper space R1 accommodating the light projecting and light receiving module is configured to be larger than the width of the lower space R2 accommodating the motor 20, and the recess 46a is formed on the outer wall of the shell 40 by the step difference between the upper space R1 and the lower space R2. The recess 46a can be used, for example, as a portion for an operator to insert his fingers to hold when setting the optical displacement meter 1. In addition, the recess 46a can be set as needed. With this structure, a gripping portion that helps to improve user convenience can be set without creating an invalid area in the shell 40.

[0107] like Figure 7As shown, the motor 20 for rotating the light projecting and light receiving module 10 integrally is accommodated in the lower space (second space) R2. The central axis of the motor 20 accommodated in the lower space R2 is consistent with the axis core of the rotating shaft 50, and the central axis is in a posture extending in the up-down direction. On the other hand, the light projecting and light receiving module 10 is accommodated in the upper space (first space) R1. The upper space R1 and the lower space R2 are arranged side by side in the direction of the rotating axis (central axis of the motor 20) of the light projecting and light receiving module 10, so the light projecting and light receiving module 10 accommodated in the upper space R1 is configured to be arranged side by side with the motor 20 accommodated in the lower space R2 in the direction of the central axis of the motor 20. In other words, it is an optical displacement meter 1 with a multi-stage structure in which the light projecting and light receiving module 10 is arranged in the upper stage and the motor 20 is arranged in the lower stage.

[0108] The light projecting and light receiving module 10 is arranged side by side with the motor 20 in the direction of the central axis of the motor 20, so when setting the positional relationship between the light projecting section 11 and the light focusing section 12 of the light projecting and light receiving module 10, it is not easily affected by the motor 20. Therefore, it is possible to design the light projecting section 11 and the light focusing section 12 so as not to be separated too far, for example, when the installation distance is relatively short.

[0109] The optical displacement meter 1 further includes a bearing 51 for rotatably supporting the rotating shaft 50 of the light projecting and light receiving module 10. As described above, the light projecting and light receiving module 10 has a large weight, so when the light projecting and light receiving module 10 is used as a bearing, the rotation shaft 50 of the light projecting and light receiving module 10 is supported. Figure 1 When the optical displacement meter 1 is used in the posture shown, a moment load is generated on the rotating shaft 50 due to the weight of the light projecting and receiving module 10. Specifically, due to the difference between the portion of the rotating shaft 50 supported by the bearing 51 and the center of gravity position of the light projecting and receiving module 10, a moment load in a direction that causes the axis to tilt relative to the horizontal plane acts on the rotating shaft 50. In particular, in the case of the above-mentioned two-stage structure, the upper shell structure 41 and the lower shell structure 42 are arranged side by side in the direction of the central axis of the motor 20 (the rotating shaft of the light projecting and receiving module 10), so the difference between the portion of the rotating shaft 50 supported by the bearing 51 and the center of gravity position of the light projecting and receiving module 10 tends to become relatively large. In contrast, the bearing 51 of the present embodiment is configured to be able to support the moment load generated by the difference between the portion of the rotating shaft 50 supported by the bearing 51 and the center of gravity position of the light projecting and receiving module 10.

[0110] As a bearing 51 capable of supporting the above-mentioned moment load, for example, a cross roller bearing as follows can be used: a plurality of rollers 51c are arranged between an annular outer ring member 51a and an inner ring member 51b so that the axes of the rollers 51c adjacent in the circumferential direction are orthogonal to each other. That is, a step portion 45a for embedding the outer ring member 51a is formed in an annular shape on the substrate portion 45 of the lower shell structure portion 42. The outer ring member 51a is fixed to the substrate portion 45 in a state of being embedded in the step portion 45a. On the other hand, an interlocking portion 50a for the inner ring member 51b to be interlocked is formed on the upper portion of the rotating shaft 50. The inner ring member 51b is fixed in a state of being interlocked in the interlocking portion 50a. In addition, the inner ring member 51b can also be fixed to the supporting member 14 of the light projection and light receiving module 10.

[0111] By using a cross roller bearing as the bearing 51, the roller 51c is in line contact with the outer ring member 51a and the inner ring member 51b, so the rigidity is greatly improved compared with the ball-type bearing. Therefore, it is possible to set a compact bearing structure that is thin in the axial direction, and can not only withstand the radial load (radial load) of the rotating shaft 50, but also the axial load (axial load), which can improve the rigidity against the above-mentioned moment load. Therefore, no matter what posture the optical displacement meter 1 is in when it is used, smooth rotation can be achieved.

[0112] The bearing 51 may also be built into the motor 20. In addition, the bearing 51 may also be a bearing other than a cross roller bearing. When a bearing other than a cross roller bearing is used, for example, two or more ball bearings are arranged at intervals from each other in the axial direction of the rotating shaft 50. Thus, a bearing structure capable of supporting the above-mentioned moment load is obtained. When two or more ball bearings are used, one ball bearing may be retained on the base plate portion 45 of the lower housing structure portion 42, and the other ball bearing may be built into the motor 20.

[0113] The optical displacement meter 1 also includes an encoder 52 for detecting the rotation angle of the rotating shaft 50, that is, the rotation angle of the light-emitting and light-receiving module 10. The encoder 52 is an optical encoder. Optical encoders have been well known, and although not shown in the figure, for example, they include a rotating plate fixed to the lower end of the rotating shaft 50 and rotating together with the rotating shaft 50, and a fixed plate fixed to the housing 40, and are configured so that light irradiated from the light-emitting body can be received by the light-receiving body after passing through slits formed at equal intervals on the rotating plate and the fixed plate, and a pulse is generated and output by converting the received light into an electrical signal.

[0114] By setting the encoder 52 as an optical encoder, the detection accuracy of the rotation angle is improved compared to the magnetic encoder, but the resistance to dust and the like is weakened. In contrast, the encoder 52 is accommodated inside the housing 40, specifically, in the sealed lower space R2 as described above, so that dust and the like are not attached to the encoder 52. For example, the space accommodating the encoder 52 is sealed, so that even if garbage and dust enter the housing 40 when adjusting the position and posture of the camera 13 in the upper space R1 accommodating the light-projecting and light-receiving module 10, the garbage and dust are prevented from entering the lower space R2 accommodating the encoder 52 from the upper space R1 accommodating the light-projecting and light-receiving module 10 and rotating the light-projecting and light-receiving module 10. Therefore, it is easy to use an optical encoder that has high accuracy but is easily affected by garbage and dust, and can perform high-precision measurements.

[0115] The motor 20 is a direct drive motor that directly drives the light projecting and receiving module 10. Direct drive refers to a driving method in which no speed reduction mechanism is inserted between the motor 20 and the driven object. In addition, as will be described later, the present invention is not limited to direct drive motors.

[0116] The motor 20 includes a stator 21 formed of a coil and a rotor 22 formed of a permanent magnet. The rotor 22 is fixed to a portion between a bearing 51 and an encoder 52 on the outer periphery of the rotating shaft 50. The stator 21 is fixed to the lower housing structure 42 and is arranged to surround the rotor 22.

[0117] The motor control unit 30 is composed of, for example, a microcomputer, ROM, RAM, etc., and operates according to a predetermined program. Specifically, the motor control unit 30 can control the current flowing in the stator 21, thereby setting the rotation speed of the motor 20 to a desired speed and the rotation angle of the motor 20 to a desired angle. The motor control unit 30 is connected to the encoder 52. The motor control unit 30 can calculate the current rotation angle of the light projection and light receiving module 10 based on the pulse signal output from the encoder 52.

[0118] When the scanning start position, scanning end position, scanning range, etc. of the slit light S1 with respect to the workpiece W are set by the inspection setting, the rotation start position, rotation end position, rotation angle, etc. of the light projecting and light receiving module 10 corresponding to the set scanning start position, scanning end position, and scanning range can be calculated. The motor control unit 30 controls the motor 20 based on the calculation result to rotate the light projecting and light receiving module 10 in a state of maintaining the Scheimpflug relationship inside the housing 40, so that the slit light S1 is scanned in a direction orthogonal to the X direction.

[0119] The light-emitting and light-receiving module 10 is accommodated in the upper space R1 of the housing 40. Therefore, depending on the rotation angle of the light-emitting and light-receiving module 10, there is a concern that a part of the light-emitting and light-receiving module 10 may contact the inner wall of the housing 40. In contrast, in the present embodiment, the rotation angle range of the light-emitting and light-receiving module 10 that rotates during the operation of the optical displacement meter 1, that is, during measurement, is set to a predetermined angle range that prevents the light-emitting and light-receiving module 10 from contacting the inner wall of the housing 40. That is, although the light-emitting and light-receiving module 10 has a size that contacts the inner wall of the housing 40 on the YZ plane orthogonal to the X direction when the light-emitting and light-receiving module 10 is assumed to rotate to the first rotation angle, the rotation angle range of the light-emitting and light-receiving module 10 that rotates during measurement is set to a predetermined angle range that is smaller than the first rotation angle to prevent the light-emitting and light-receiving module 10 from contacting the inner wall of the housing 40. With this structure, the housing 40 can be designed based on the angle range required for the rotation of the light-emitting and light-receiving module 10, so that the housing 40 can be easily miniaturized.

[0120] As a method for setting the rotation angle range of the light projecting and receiving module 10 to a predetermined angle range, there are, for example, a method of mechanical implementation and a method of software implementation. In this embodiment, as a method of mechanical implementation, a device such as a controller is provided inside the housing 40. Figure 4 As shown in the figure, a first stopper 61 and a second stopper 62 are provided as an example of a mechanical part. In this example, the first stopper 61 and the second stopper 62 are provided to protrude upward from the base plate 45. When the light projecting and light receiving module 10 rotates in the direction of arrow B around the rotation center line A, before a part of the light projecting and light receiving module 10 contacts the inner wall of the housing 40, the light projecting and light receiving module 10 contacts the first stopper 61, thereby preventing the light projecting and light receiving module 10 from further rotating in the direction of arrow B. In addition, when the light projecting and light receiving module 10 rotates in the direction of arrow C around the rotation center line A, before a part of the light projecting and light receiving module 10 contacts the inner wall of the housing 40, the light projecting and light receiving module 10 contacts the second stopper 62, thereby preventing the light projecting and light receiving module 10 from further rotating in the direction of arrow C. That is, the first stopper 61 and the second stopper 62 are provided inside the housing 40 for preventing the light projecting and light receiving module 10 from rotating out of a predetermined angle range during measurement.

[0121] The first stopper 61 and the second stopper 62 can also be made of elastic members such as rubber or thermoplastic elastomer. Alternatively, the first stopper 61 and the second stopper 62 can be made of metal, and elastic members can be provided at the portion of the support member 14 where the first stopper 61 and the second stopper 62 abut. Thus, the sound generated when the light projecting and light receiving module 10 abuts against the first stopper 61 and the second stopper 62 can be reduced.

[0122] In addition, it is preferred that the support member 14 abuts against the first stopper 61 and the second stopper 62. This is because if the light projecting unit 11, the light focusing unit 12, etc. abut against the first stopper 61 and the second stopper 62, there is a concern that the optical axis may deviate due to the impact during the abutment. In addition, the first stopper 61 and the second stopper 62 may also be provided on the upper peripheral wall portion 43. Furthermore, only one of the first stopper 61 and the second stopper 62 may also be provided.

[0123] Next, the software-based method is described. That is, by executing the contact avoidance control by the motor control unit 30, the contact between the light projecting and light receiving module 10 and the inner wall of the housing 40 can also be avoided. The motor control unit 30 controls the motor 20 based on the rotation angle obtained by calculating the pulse signal output from the encoder 52, so that the light projecting and light receiving module 10 is rotated within a specified angle range during measurement. This control is the contact avoidance control. By executing the contact avoidance control, the contact between the light projecting and light receiving module 10 and the inner wall of the housing 40 can be avoided without setting the stoppers 61 and 62. In addition, the stoppers 61 and 62 can also be set when the contact avoidance control is executed.

[0124] It is sufficient as long as the light projecting and light receiving module 10 does not contact the inner wall of the housing 40 during measurement. The light projecting and light receiving module 10 may contact the inner wall of the housing 40 during non-measurement such as maintenance or various settings, so the motor control unit 30 can be configured to perform contact avoidance control only during measurement.

[0125] like Figure 8 As shown in FIG. 1 , a substrate storage space (third space) R3 is provided in the lower housing structure portion 42. Figure 4 In the top view shown, the substrate accommodating space R3 is offset to the far rear side relative to the center of the housing 40, and is therefore positioned at a position close to the motor 20 (in Figure 7In addition, the substrate accommodating space R3 is located below the upper space R1 that accommodates the light projecting and light receiving module 10, and is therefore a different space from the upper space R1, and is also a different space from the lower space R2. In the direction of the rotation axis of the light projecting and light receiving module 10, the substrate accommodating space R3 is configured at a position different from the upper space R1, and on the other hand, is configured at the same position as the lower space R2 that accommodates the motor 20. When observed along the rotation axis of the light projecting and light receiving module 10, the upper space R1 and the lower space R2 are configured at positions overlapping the rotation axis, and on the other hand, the substrate accommodating space R3 is configured at a position not overlapping the rotation axis. For example, in a case where the size of the light projecting and light receiving module 10 is larger than the size of the motor 20, by setting it as a two-stage structure with the upper space R1 that accommodates the light projecting and light receiving module 10 as the first stage and the lower space R2 that accommodates the motor 20 and the substrate accommodating space R3 that accommodates the motor control unit 30 as the second stage, the outer shape of the housing 40 can be made more compact.

[0126] like Figure 8 As shown, the motor control board 31 on which the motor control unit 30 is mounted, the signal processing board 33 on which the signal processing unit 32 is mounted, and the power supply board 35 on which the power supply unit 34 is mounted are accommodated in the board accommodation space R3. The motor control board 31 and the signal processing board 33 are equipped with processors such as CPU (central processing unit), DSP (digital signal processor), FPGA (field programmable gate array) that function as the motor control unit 30 and the signal processing unit 32, and are equipped with storage elements such as RAM (random access memory) and ROM (read only memory) for storing programs executed by the processors (not shown). Each board 31, 33, 35 is fixed to the lower housing structure 42. The motor control unit 30 and the signal processing unit 32 are accommodated in the board accommodation space R3 different from the upper space R1, so that the light projection unit 11 that is particularly prone to heat can be thermally separated from the motor control unit 30 and the signal processing unit 32, and the operation of the motor control unit 30 and the signal processing unit 32 can be stabilized. The arrangement of the control unit 3 is not limited to the above example, and for example, the signal processing unit 32 may be accommodated in the housing 40 and the motor control unit 30 may be arranged outside the housing 40 .

[0127] The reflected light S2 is incident from the front side of the housing 40, so the motor control unit 30, the signal processing unit 32, and the power supply unit 34 accommodated in the far rear side of the housing 40 are arranged on the side opposite to the side where the reflected light S2 is incident relative to the light projection and light receiving module 10. As a result, the motor control unit 30, the signal processing unit 32, and the power supply unit 34 do not interfere with the displacement measurement. In addition, when the Z direction is used as a reference, the motor control unit 30, the signal processing unit 32, and the power supply unit 34 are arranged in a manner adjacent to the light projection and light receiving module 10 in the Z direction. In addition, the substrate storage space R3 is sealed by the cover member 47, so that dust and the like can be prevented from adhering to each substrate 31, 33, 35.

[0128] The signal processing board 33 is located at the top, the motor control board 31 is located below the signal processing board 33, and the power supply board 35 is located below the motor control board 31. The signal processing board 33 located at the top is closest to the light-projecting and light-receiving module 10, but the signal processing board 33 is located below the support member 14 of the light-projecting and light-receiving module 10. Therefore, when the light-projecting and light-receiving module 10 rotates within a predetermined angle range, it will not contact the signal processing board 33. In other words, the motor control unit 30, the signal processing unit 32, and the power supply unit 34 are all configured to avoid contact with the light-projecting and light-receiving module 10 rotating during measurement.

[0129] The power supply unit 34 is a part that supplies power to the light projection unit 11, the camera unit 13, the motor control unit 30, and the signal processing unit 32. In the present embodiment, the power supply unit 34, the motor control unit 30, and the signal processing unit 32 are mounted on different substrates, but the present invention is not limited thereto, and any two or more of them may be mounted on one substrate in an integrated manner.

[0130] The signal processing unit 32 is composed of, for example, a microcomputer, ROM, RAM, etc., operates according to a predetermined program, and is a part that generates cross-sectional profile data of the workpiece W based on the amount of light received by the imaging unit 13. Figure 4 The wirings indicated by reference numeral 70 connect the substrates 31, 33, and 35 to the light projecting unit 11 and the imaging unit 13. The wirings 70 are flexible and are configured not to affect the rotation of the light projecting and receiving module 10.

[0131] like Fig. 9 As shown in FIG. 1 , the image sensor 13a of the imaging unit 13 has a plurality of pixels arranged two-dimensionally in a U direction corresponding to the X direction and in a V direction orthogonal to the U direction. The signal processing unit 32 obtains the brightness value (amount of received light) of each pixel of the image sensor 13a and obtains an approximate curve of brightness value changes. The signal processing unit 32 calculates the peak position in the V direction of each pixel column in the obtained approximate curve and obtains the calculated peak position as the displacement of the workpiece W.

[0132] The signal processing unit 32 performs the above-mentioned peak position calculation multiple times during the rotation of the light-emitting and light-receiving module 10. The signal processing unit 32 associates the obtained peak position with the rotation angle of the light-emitting and light-receiving module 10 when the peak position is obtained, and stores it as measurement data. The rotation angle and UV coordinates of the light-emitting and light-receiving module 10 correspond to the XYZ coordinates of the workpiece, so the cross-sectional profile data of the workpiece W at the desired rotation angle can be generated based on the measurement data. In addition, by obtaining multiple cross-sectional profiles of the workpiece W at different rotation angles, the signal processing unit 32 can generate data on the three-dimensional shape of the workpiece W.

[0133] (Variation 1 of Implementation Example 1)

[0134] Fig.10 FIG. 1 shows a light-projecting and light-receiving module 10 according to a first variation of the first embodiment. The positions of the light-projecting unit 11, the light-collecting unit 12, the imaging unit 13, and the light-receiving-side reflective member 15 of the light-projecting and light-receiving module 10 according to the first variation are different from those of the above-mentioned embodiment. Specifically, the rotation axis 50 of the light-projecting and light-receiving module 10 is arranged at a position overlapping with the light-collecting unit 12 on the YZ plane. That is, as described above, although it is desired to reduce the moment of inertia generated by the rotation of the light-projecting and light-receiving module 10 as much as possible, when the configuration is as follows: Figure 5 When the counterweight 16 shown by the virtual line is provided, the weight of the light-projecting and light-receiving module 10 increases, which is sometimes not ideal. Therefore, the counterweight 16 is not provided, and as a method of reducing the moment of inertia generated by the rotation of the light-projecting and light-receiving module 10, a method of making the light-collecting part 12 with increased weight overlap with the rotation axis 50 of the light-projecting and light-receiving module 10 in the YZ plane can be adopted. Thus, at least a part of the light-collecting part 12 is arranged on the extension line of the rotation axis 50 of the light-projecting and light-receiving module 10. In addition, the rotation axis 50 does not need to completely overlap with the light-collecting part 12, as long as at least a part of the rotation axis 50 and at least a part of the light-collecting part 12 overlap with each other when viewed from the direction of the rotation center line A. Thus, the counterweight 16 is not required, or the counterweight 16 can be made light.

[0135] In addition, in Modification 1, the imaging unit 13 and the light-receiving side reflective member 15 are arranged to sandwich the light-collecting unit 12. Thus, the light-collecting unit 12 of Modification 1 is arranged on the optical path between the light-receiving side reflective member 15 and the imaging unit 13 on the YZ plane, so that the light reflected by the light-receiving side reflective member 15 is collected and incident on the imaging unit 13.

[0136] Furthermore, the light-projecting and light-receiving module 10 of variant example 1 is provided with a light-projecting side reflection member 17. That is, the light-projecting unit 11 of variant example 1 is configured so that the slit light S1 irradiated from the optical system 11b goes to the far rear side on the left. Thus, the light-projecting unit 11 can be brought closer to the rotation center line A, and the moment of inertia generated by the rotation of the light-projecting and light-receiving module 10 can be further reduced, but the workpiece W is located on the opposite side to the slit light S1 irradiated from the optical system 11b. The light-projecting side reflection member 17 is configured so that the slit light S1 emitted from the optical system 11b of the light-projecting unit 11 is reflected toward the workpiece W side to cope with the above situation. The light-projecting side reflection member 17 is fixed to the supporting member 14 or the light-projecting unit 11, and the relative positional relationship between the light-projecting side reflection member 17 and the light-projecting unit 11 does not change even if the light-projecting and light-receiving module 10 rotates.

[0137] (Variation 2 of Implementation Example 1)

[0138] Fig.11 and Fig.12 An optical displacement meter 1 according to a second modification of the first embodiment is shown. Fig.11 This is a diagram showing the internal structure of the optical displacement meter 1 as viewed from above. Fig.12 This is a diagram showing the internal structure of the optical displacement meter 1 as viewed from the bottom.

[0139] In the optical displacement meter 1 of the second modification, the motor 20 is not a direct drive motor, but is a structure that rotates the light projecting and receiving module 10 via the speed reduction mechanism 25. Fig.11 As shown, the motor 20 and the light projecting and receiving module 10 are accommodated in the upper space R1. Fig.12 As shown, the output shaft 20a of the motor 20 passes through the substrate 45 downward to reach the lower space R2. In addition, the driven shaft 10a fixed to the light projecting and receiving module 10 also passes through the substrate 45 downward to reach the lower space R2.

[0140] The speed reduction mechanism 25 is accommodated in the lower space R2, and includes a driving pulley 25a fixed to the output shaft 20a of the motor 20, a driven pulley 25b fixed to the driven shaft 10a, and a transmission belt 25c wound around the driving pulley 25a and the driven pulley 25b. The driving pulley 25a is set to have a smaller diameter than the driven pulley 25b. The transmission belt 25c is a synchronous belt.

[0141] In Modification 2, when the output shaft 20a of the motor 20 accommodated in the upper space R1 rotates, the driving pulley 25a rotates, and the rotational force of the driving pulley 25a is transmitted to the driven pulley 25b via the transmission belt 25c. The driving force transmitted to the driven pulley 25b is transmitted to the driven shaft 10a, so that the light projecting and light receiving module 10 can be rotated by the motor 20. In the case of Modification 2, the driven shaft 10a is the rotation axis of the light projecting and light receiving module 10.

[0142] In addition, the speed reduction mechanism 25 is not limited to the combination of the pulleys 25a, 25b and the transmission belt 25c, and can also be composed of a combination of a driving sprocket, a driven sprocket and a synchronous chain, or a combination of multiple gears. Regarding the type of the motor 20, for example, a DC motor, a stepping motor, a servo motor, etc. can be used.

[0143] (Implementation Method 2)

[0144] Figure 13 to Figure 15 1 is a diagram showing an optical displacement meter 1 according to Embodiment 2 of the present invention. In Embodiment 2, the structure of the housing 400, the positional relationship between the motor 20 and the light-emitting and light-receiving module 100, etc. are different from those in Embodiment 1. Hereinafter, the same reference numerals are given to the same parts as in Embodiment 1 and the description thereof is omitted, and the different parts are described in detail.

[0145] like Fig.13 and Fig.15 As shown, the housing 400 is a one-stage structure, and the substrates 31, 33, 35 are also accommodated in the housing 400. The housing 400 can also be divided so that the space accommodating the substrates 31, 33, 35 and the space accommodating the light projecting and receiving module 100 are different spaces.

[0146] The housing 400 includes a lower wall 401, a peripheral wall 402 extending upward from the peripheral edge of the lower wall 401, and an upper cover member 403 for closing the upper open portion. A light projection window 402a through which the slit light S1 irradiated from the light projection unit 11 passes, and a light receiving window 402b through which the reflected light S2 reflected from the workpiece W passes are provided at the front side of the peripheral wall 402.

[0147] like Fig.15 As shown, an annular wall portion 404 is formed at the central portion of the lower wall portion 401, which protrudes toward the inside of the housing 400 and extends around the rotation center line A. An end wall portion 405 is formed at the front end portion of the annular wall portion 404, which extends radially along the rotation center line A. An opening portion 405a for inserting the rotating shaft 50 is formed at the central portion of the end wall portion 405.

[0148] A motor accommodation space R4 is formed inside the annular wall portion 404. The stator 21 and the rotor 22 of the motor 20 are accommodated in the motor accommodation space R4. The stator 21 of the motor 20 is fixed to the inner surface of the annular wall portion 404. That is, in the present embodiment, the stator holding portion is constituted by the annular wall portion 404 and the end wall portion 405. On the other hand, the rotor 22 of the motor 20 is fixed to the rotating shaft 50.

[0149] The outer ring member 51a of the bearing 51 is fixed to the end wall portion 405 in a state of being fitted into the step portion 405b formed in the end wall portion 405. Thus, the bearing 51 is held by the stator holding portion constituted by the annular wall portion 404 and the end wall portion 405. On the other hand, the inner ring member 51b is fitted into the fitting portion 50a formed on the rotating shaft 50.

[0150] The motor accommodation space R4 also accommodates the encoder 52. A lower cover member 406 is provided at the lower end of the housing 400. The motor accommodation space R4 is sealed by the lower cover member 406, so that dust and the like do not adhere to the encoder 52.

[0151] Similar to the first embodiment, the light projecting and receiving module 100 includes a light projecting unit 11, a light focusing unit 12, an imaging unit 13, a weight 16, etc. However, a supporting member 110 that integrally holds the light projecting unit 11, the light focusing unit 12, and the imaging unit 13 is greatly different from the supporting member 14 of the first embodiment.

[0152] That is, in Embodiment 1, the light projecting and light receiving module 10 and the motor 20 (bearing 51 and encoder 52) are arranged side by side in the direction of the rotating shaft 50 (height direction), whereas in Embodiment 2, a portion of the height range in the direction of the rotating shaft 50 of the light projecting and light receiving module 100 includes at least one of the motor 20, the bearing 51 supporting the rotating shaft 50, and the encoder 52 connected to the motor 20. Thus, when setting the positional relationship between the light projecting unit 11 and the light focusing unit 12 of the light projecting and light receiving module 100, a design can be made that takes into account the large spacing between the light projecting unit 11 and the light focusing unit 12, such as when the installation distance is relatively long.

[0153] Specifically, the support member 110 includes a fixing portion 111 fixed to the rotating shaft 50, a one side longitudinal plate portion 112 and a second side longitudinal plate portion 113, a light focusing portion holding portion 114, and a light projecting portion holding portion 115. The fixing portion 111, the one side longitudinal plate portion 112, the second side longitudinal plate portion 113, the light focusing portion holding portion 114, and the light projecting portion holding portion 115 may be integrally formed or may be formed by combining different components.

[0154] The fixing portion 111 is in the shape of a plate extending in the radial direction of the rotating shaft 50. Fig.14As shown in the circular shape, Fig.15 As shown in FIG. 1 , the end wall portion 405 is arranged to cover the end wall portion 405 from above. Fig.15 The right side, that is, one side of the fixing portion 111 in the radial direction of the rotating shaft 50, extends downward along the direction of the rotating shaft 50. The other side longitudinal plate portion 113 extends from Fig.15 The left side of the fixing portion 111, that is, the other side in the radial direction of the rotating shaft 50, extends downward along the direction of the rotating shaft 50. The one side longitudinal plate portion 112 and the other side longitudinal plate portion 113 are configured to face the annular wall portion 404. In addition, the one side longitudinal plate portion 112 and the other side longitudinal plate portion 113 are curved into an arc shape in the same manner as the annular wall portion 404. When the light projecting and receiving module 100 rotates, the one side longitudinal plate portion 112 and the other side longitudinal plate portion 113 rotate in a state of maintaining a certain gap with the annular wall portion 404.

[0155] In addition, the one side longitudinal plate portion 112 and the other side longitudinal plate portion 113 may be formed integrally. For example, an annular peripheral wall portion (not shown) extending downward from the peripheral edge of the fixing portion 111 may be formed, and the one side longitudinal plate portion 112 and the other side longitudinal plate portion 113 may be formed with a circumferential portion of the peripheral wall portion.

[0156] The light focusing unit holder 114 is in the shape of a plate extending from the lower end of the one side longitudinal plate portion 112 in the radial direction of the rotation axis 50. The light focusing unit 12, the imaging unit 13, the cover glass 13c, etc. are held on the upper surface of the light focusing unit holder 114. Therefore, the rotation axis 50 of the light projecting and receiving module 100 is arranged at a position that does not overlap with the light focusing unit 12 and the imaging unit 13 on the YZ plane.

[0157] The light projecting unit holder 115 is in the shape of a plate extending from the lower end of the other side longitudinal plate portion 113 in the radial direction of the rotation axis 50. The light projecting unit 11, the counterweight 16, etc. are held on the upper surface of the light projecting unit holder 115. Therefore, the rotation axis 50 of the light projecting and receiving module 100 is arranged at a position that does not overlap with the light projecting unit 11 on the YZ plane.

[0158] Thus, the light focusing unit holder 114 and the light projecting unit holder 115 are arranged to sandwich the rotation axis 50 and to protrude in opposite directions to each other in the radial direction of the rotation axis 50. The counterweight 16 can be fixed to the light projecting unit holder 115. Alternatively, the counterweight 16 can be fixed to a position on the side of the fixing unit 111 opposite to the side on which the one side longitudinal plate portion 112 is formed.

[0159] The support member 110 including the fixing portion 111, the one side vertical plate portion 112, the other side vertical plate portion 113, the focusing portion holding portion 114, and the projection portion holding portion 115 has a plurality of curved portions 110A in the cross section in the X direction. Since the support member 110 has a plurality of curved portions 110A in this way, the rigidity can be improved compared to the case where the support member 110 is a flat plate.

[0160] The motor 20 and the bearing 51 are arranged between the longitudinal plate portion 112 on one side and the longitudinal plate portion 113 on the other side of the support member 110. Moreover, the bearing 51 is arranged at a position between the longitudinal plate portion 112 on one side and the longitudinal plate portion 113 on the other side, where the distance from the fixing portion 111 is closer than the distance from the motor 20. Thus, the motor 20 and the bearing 51 are included in a portion of the height range of the light projecting and light receiving module 100. In addition, although not shown in the figure, only the motor 20 may be included in the height range of the light projecting and light receiving module 100, or only the bearing 51 may be included in the height range of the light projecting and light receiving module 100.

[0161] The rotation drive unit is composed of at least the motor 20, the bearing 51, and the encoder 52. In addition, the motor 20 is fixed to a wall surface (the lower wall portion 401 and the annular wall portion 404) adjacent to a light-projecting and light-receiving surface provided with a light-projecting window 402a for passing slit light and a light-receiving window 402b for passing reflected light (also collectively referred to as light-projecting and light-receiving windows).

[0162] The light-projecting and light-receiving window of this embodiment is composed of a light-projecting window 402a and a light-receiving window 402b which is independent of the light-projecting window 402a. However, the light-projecting window and the light-receiving window may be formed integrally. Figure 4 , Fig.14 In that case, it is a surface formed by a plurality of planes formed by the windows. In the case where the light-projecting and light-receiving windows are formed integrally, the light-projecting and light-receiving surface may be a surface formed by a single plane formed by the light-projecting and light-receiving windows.

[0163] The supporting member 110 supports the light projecting and light receiving module 100 in a manner such that the light projecting and light receiving module 100 is located in a plane orthogonal to the X direction and in which the rotating drive unit exists. The supporting member 110 has a first portion (e.g., a fixing portion 111) and a second portion (e.g., a focusing portion holding portion 114 and a light projecting portion holding portion 115) formed by a plurality of curved portions 110A, which have different heights in the direction of the rotation axis, and the rotating drive unit and the light projecting and light receiving module 100 exist between the plane formed by the first portion and the plane formed by the second portion on at least a portion of the cross section including the rotation axis. With this structure, the rigidity of the supporting member 110 can be improved, and the thickness of the housing 400 in the X direction can be reduced.

[0164] In addition, although not shown, the encoder 52 may also be included in the height range of the light-emitting and light-receiving module 100. For example, the encoder 52 may be disposed at the middle portion or the upper end portion of the rotating shaft 50, so that the encoder 52 is included in the height range of the light-emitting and light-receiving module 100. Alternatively, only the encoder 52 may be included in the height range of the light-emitting and light-receiving module 100, or only the motor 20 and the encoder 52 may be included in the height range of the light-emitting and light-receiving module 100, or only the bearing 51 and the encoder 52 may be included in the height range of the light-emitting and light-receiving module 100.

[0165] The light-receiving side reflective member 15 is arranged on the optical path between the light-collecting section 12 and the light-receiving window 402b of the housing 400 on the YZ plane, and reflects the reflected light S2 that has passed through the light-receiving window 402b toward the light-collecting section 12. That is, the light-collecting section 12 is arranged on the optical path between the light-collecting side reflective member 15 and the imaging section 13 on the YZ plane, and the reflected light S2 reflected by the light-receiving side reflective member 15 is concentrated and incident on the imaging section 13. Thus, the reflected light S2 can be folded back toward the light-projecting section 11 side, so that the distance between the imaging section 13 or the light-collecting section 12 and the rotation axis 50 of the light-projecting and light-receiving module 100 on the YZ plane becomes shorter.

[0166] (Variation of Implementation Example 2)

[0167] Fig.16 1 is a diagram showing an optical displacement meter 1 according to a modification of Embodiment 2. This modification omits the light-receiving-side reflective member 15. The light-collecting unit 12 is arranged so that the optical axis of the light-collecting unit 12 faces the light-receiving window 402b of the housing 400, thereby eliminating the need for the reflective member 15.

[0168] This modification is an example of a layout in which a wide interval is ensured between the light projecting unit 11 and the light collecting unit 12. For example, this modification can be applied when the installation distance is relatively long.

[0169] The above-mentioned embodiments are merely illustrative in all aspects and are not intended to be interpreted in a restrictive manner. Furthermore, all modifications and variations that fall within the equivalent scope of the claims are modifications and variations within the scope of the present invention. For example, in embodiment 2, a light-projecting side reflective component may also be provided. In addition, in embodiment 2, a speed reduction mechanism may also be provided. In addition, in embodiments 1 and 2, the motor 20 may also be provided outside the housing 40, 400.

[0170] (Implementation method 3)

[0171] Fig.17 It is a schematic diagram showing a state where the three-dimensional shape of a workpiece W is measured. Fig.18 This is a block diagram of the optical displacement meter 1 according to the third embodiment of the present invention. Fig.17The mark W1 in shows the surface of the workpiece W. The optical displacement meter 1 is configured to irradiate the slit light S1 from the upper direction surface W1 of the workpiece W. The motor 20 causes the light-projecting and light-receiving module 10 to swing integrally in a manner of reciprocating in two directions, clockwise or counterclockwise, around the rotating shaft 50 of the supporting member 14. The clockwise direction refers to the right-hand direction when observed along the extension direction (X direction) of the rotating shaft 50, and the counterclockwise direction refers to the left-hand direction when observed along the rotating shaft 50. The motor control unit 30 controls the motor 20 to swing the light-projecting and light-receiving module 10 in a manner of reciprocating in the above-mentioned two directions, so as to scan the slit light S1 in a direction orthogonal to the X-direction. Thus, the camera unit 13 can acquire a plurality of light-receiving images during the period when the motor control unit 30 swings the light-projecting and light-receiving module 10 in one of the above-mentioned two directions.

[0172] As described above, by rotating the light projecting and receiving module 10, the slit light S1 scans the workpiece W in a direction orthogonal to the X direction. Therefore, the camera control unit 13b can generate a cross-sectional profile representing the height of the workpiece W in the Z direction based on the pixel signals read from the image sensor 13a at different rotation angles of the light projecting and receiving module 10.

[0173] like Fig.17 As shown, when measuring the displacement of a workpiece W whose surface W1 is at the same height (the surface W1 is parallel to the Y direction), if it is assumed that the optical displacement meter 1 is moved straight in a direction parallel to the surface W1 of the workpiece W (indicated by arrow E), then since the surface W1 is at the same height, the area that is the object of reading the pixel signal of the image sensor 13a can be limited to a local area to speed up the processing.

[0174] On the other hand, when the slit light S1 is scanned in a direction perpendicular to the X direction by rotating the light projecting and receiving module 10 as in the present embodiment, the surface W1 of the workpiece W may not be measured in the Y direction as described below. Fig.17 In the embodiment, the maximum area that can be read by the image sensor 13a is set to be the maximum area (measurable range) F1 that is substantially arc-shaped and has a predetermined depth centered on the rotation axis 50 of the imaging unit 13. If the area to be read from the pixel signal of the image sensor 13a when measuring the displacement is always set to the maximum area F1, the processing amount of the signal processing unit 32 increases, and it is difficult to achieve high-speed measurement. Therefore, it is conceivable that the area to be read from the pixel signal of the image sensor 13a is set to be the area below the line L1, that is, the local area (acquisition range) F2.

[0175] However, when the light projecting and light receiving module 10 is rotated, the local area F2 is an arc-shaped and long area centered on the rotation center line A of the light projecting and light receiving module 10. Therefore, even if the surface W1 of the workpiece W is at the same height, the portion to the right of the straight line L2 is located outside the local area F2, and thus the local area F2 cannot be used for measurement.

[0176] In this case, if Fig.19 As shown, the imaging control unit 13b of the third embodiment is configured to dynamically change the local area F3 (the part indicated by the oblique lines, which corresponds to the acquisition range) as the object of reading the pixel signal of the image sensor 13a according to the rotation angle of the light projecting and receiving module 10. The imaging control unit 13b is configured to acquire the rotation angle of the motor 20 based on the rotation angle acquisition unit 36 ​​described later, so that the position of the local area F3 in the image sensor 13a can be changed in the V direction of the image sensor 13a according to the rotation angle of the motor 20.

[0177] based on Fig.19 The following is an example in which the camera control unit 13b changes the position of the local area F3. When the rotation angle of the light-projecting and light-receiving module 10 is θ1, the camera control unit 13b sets the position of the local area F3 in the image sensor 13a so that the local area F3 is the lower area of ​​the image sensor 13a. When the rotation angle of the light-projecting and light-receiving module 10 is θ2, the camera control unit 13b sets the position of the local area F3 in the image sensor 13a so that the local area F3 is the middle area in the vertical direction of the image sensor 13a. When the rotation angle of the light-projecting and light-receiving module 10 is θ3, the camera control unit 13b sets the position of the local area F3 in the image sensor 13a so that the local area F3 is the upper area of ​​the image sensor 13a. That is, when the rotation angle of the light-projecting and light-receiving module 10 changes from θ1 to θ3, the local area F3 changes from the lower area of ​​the image sensor 13a to the upper area along with the angle change. Conversely, when the rotation angle of the light-projecting and light-receiving module 10 changes from θ3 to θ1, the local area F3 changes from the upper area of ​​the image sensor 13a to the lower area along with the angle change. In addition, the rotation angle of the motor 20 corresponds to the rotation angle of the light-projecting and light-receiving module 10, so when this control is performed each time, either the rotation angle of the motor 20 or the rotation angle of the light-projecting and light-receiving module 10 can be used. Here, it is assumed that the motor 20 is a direct drive motor described later, so the rotation angle of the motor 20 is equal to the rotation angle of the light-projecting and light-receiving module 10. In addition, in the case of using the motor 20 and the speed reduction mechanism 25, the rotation angle of the motor 20 and the rotation angle of the light-projecting and light-receiving module 10 may also differ depending on the rotation ratio.

[0178] The imaging control unit 13b sets the width H1 of the local area F3 in the V direction when the rotation angle of the light-emitting and light-receiving module 10 is θ1, the width H2 of the local area F3 in the V direction when the rotation angle of the light-emitting and light-receiving module 10 is θ2, and the width H3 of the local area F3 in the V direction when the rotation angle of the light-emitting and light-receiving module 10 is θ3 to be the same. In short, the imaging control unit 13b makes the number of pixels read in the V direction of the local area F3 at different rotation angles of the light-emitting and light-receiving module 10 the same, and changes the local area F3 at each rotation angle so that the area of ​​the light-receiving amount read in the substantially arc-shaped measurable range F1 includes a common height in the Z direction. If the surface of the workpiece W is flat, the imaging control unit 13b can also change the local area F3 at each rotation angle so that the area of ​​the light-receiving amount read in the substantially arc-shaped measurable range F1 is substantially consistent in the Z direction from one end to the other end of the substantially arc-shaped measurable range F1. Thus, regardless of the rotation angle of the light-projecting and light-receiving module 10, the imaging control unit 13b can move the local area F3 from which the pixel signal is read from the image sensor 13a in the V direction in such a manner that at least a portion of the measurement range in the Z direction is common. In addition, the width H1 of the local area F3 in the V direction when the rotation angle of the light-projecting and light-receiving module 10 is θ1 may be different from the width H2 of the local area F3 in the V direction when the rotation angle of the light-projecting and light-receiving module 10 is θ2. Similarly, the width H1 of the local area F3 in the V direction when the rotation angle of the light-projecting and light-receiving module 10 is θ1 may be different from the width H3 of the local area F3 in the V direction when the rotation angle of the light-projecting and light-receiving module 10 is θ3.

[0179] In addition, at least one of the light projecting and light receiving module 10 and the signal processing unit 32 may change the parameter related to the light amount according to the rotation angle. The parameter related to the light amount includes, for example, at least one of the light amount of the slit light S1 emitted by the light projecting unit 11, the exposure time of the image sensor 13a, the gain of the image sensor 13a, and the detection sensitivity (threshold value of the light amount detected as a peak) for detecting the peak position by the signal processing unit 32.

[0180] If it is assumed that the amount of emitted light is constant regardless of the rotation angle, there is a tendency that the amount of reflected light at other rotation angles decreases compared to the amount of received light (amount of reflected light) of the reflected light S2 at a rotation angle (hereinafter also referred to as a reference angle) at which the projection axis of the light projecting unit 11 and the light receiving axis of the imaging unit 13 are in a regular reflection relationship with respect to the XY plane (a relationship in which the incident angle and the reflection angle are equal). Fig.19In the embodiment, as the angle changes from θ3 to θ1, the amount of reflected light tends to decrease. Therefore, the light projection control unit 11c may also increase the amount of emitted light as the amount of change of the rotation angle relative to the reference angle increases. In addition, as the amount of change of the rotation angle relative to the reference angle increases, the camera control unit 13b may also extend the exposure time of the image sensor 13a or increase the gain of the image sensor 13a. Thus, the decrease in the amount of light received in each light-receiving image due to the decrease in the amount of reflected light can be suppressed, thereby improving the calculation accuracy of the peak position.

[0181] In addition, the signal processing unit 32 may also reduce the detection sensitivity as the change in the rotation angle of the received light image relative to the reference angle increases when calculating the UV coordinate of the peak position based on the received light image. This can suppress the decrease in the calculation accuracy of the peak position due to the decrease in the amount of light received in each received light image caused by the decrease in the amount of reflected light.

[0182] In addition, the reference angle is not limited to the rotation angle that is in a regular reflection relationship, and can also be set according to the shape, material, surface condition, and external environment of the workpiece.

[0183] (Generation of height image)

[0184] like Fig.18 As shown, the optical displacement meter 1 of the third embodiment includes a rotation angle acquisition unit 36 ​​for acquiring the rotation angle achieved by the motor 20. The rotation angle acquisition unit 36 ​​may be composed of the encoder 52 for detecting the rotation angle of the light-emitting and light-receiving module 10 as described above, or may be composed of a calculation unit for calculating the rotation angle of the light-emitting and light-receiving module 10 by detecting the time when the rotation achieved by the motor 20 starts and setting the light-emitting and light-receiving module 10 to move at a constant speed.

[0185] The signal processing unit 32 acquires the light receiving amount distribution output by the image sensor 13a and the rotation angle realized by the motor 20 detected by the rotation angle acquisition unit 36. The signal processing unit 32 is a part that performs the following conversion processing: the UV coordinate is calculated based on the light receiving amount distribution output by the image sensor 13a, and the UV coordinate and the rotation angle realized by the motor 20 are converted into XYZ coordinates based on a predetermined conversion condition.

[0186] The light-projecting and light-receiving module 10 is swung, so the signal processing unit 32 acquires a plurality of light-receiving images obtained during the swinging of the light-projecting and light-receiving module 10 in one direction of the clockwise direction and the counterclockwise direction from the imaging unit 13. In addition, the signal processing unit 32 acquires the rotation angles corresponding to the plurality of light-receiving images obtained during the swinging of the light-projecting and light-receiving module 10 in one direction from the rotation angle acquisition unit 36. Then, the signal processing unit 32 converts the plurality of light-receiving images obtained during the swinging of the light-projecting and light-receiving module 10 in one direction and the rotation angles corresponding to the respective light-receiving images into a plurality of XYZ coordinates based on a predetermined conversion condition.

[0187] The optical displacement meter 1 includes a height image output unit 37. The height image output unit 37 is composed of, for example, a microcomputer, a ROM, a RAM, etc., and operates according to a predetermined program stored in the ROM, etc., to obtain the XYZ coordinates obtained by the transformation processing of the signal processing unit 32. The height image output unit 37 outputs a height image representing the height of the workpiece W on the XY plane based on the obtained XYZ coordinates. The height image is not a three-dimensional image in which a polygon is formed with each pixel as a vertex, nor is it an image obtained by observing a three-dimensional point group only from a perspective directly above, but rather an image containing height data instead of a brightness value, and can also be called a distance image.

[0188] (Setting the acquisition range)

[0189] In the optical displacement meter 1 according to the present embodiment, the user can set the acquisition range for obtaining the measurement result while observing the height image, and the acquisition range setting by the user can be accepted. Fig.18 As shown, the optical displacement meter 1 of the third embodiment includes a screen generation unit 38 for generating various screens. The screen generation unit 38 is composed of, for example, a microcomputer, a ROM, a RAM, etc., operates according to a predetermined program stored in the ROM, etc., and outputs the generated screen data to the display unit 3A. The display unit 3A is a part that displays various screens based on the screen data obtained from the screen generation unit 38, and is composed of, for example, a liquid crystal display device, an organic EL display device, etc.

[0190] In the optical displacement meter 1, the user's operation status on the operation unit 3B can be obtained through the control unit 3. The operation unit 3B is composed of, for example, a keyboard, a mouse, etc. The display unit 3A and the operation unit 3B may be components constituting a part of the optical displacement meter 1, or may be components constituting a part of a setting device formed of a personal computer or the like different from the optical displacement meter 1, and either one is connected to the screen generation unit 38.

[0191] like Fig. 20As shown, the screen generation unit 38 generates a setting screen 530 and displays the setting screen 530 on the display unit 3A, in which the first screen 510 showing the height image and the second screen 520 showing the YZ cross-sectional profile of the workpiece W corresponding to the X coordinate in the height image are displayed simultaneously or switched. In this example, a case where the workpiece W is a screw is shown, and the setting screen 530 simultaneously displays the first screen 510 and the second screen 520. The screen generation unit 38 obtains data of the height image output from the height image output unit 37, and displays the height image in the first screen 510. A first coordinate system display unit 511 indicating the X direction and the Y direction is provided in the first screen 510. In this example, the horizontal direction of the first screen 510 is the X direction, and the vertical direction of the first screen 510 is the Y direction, and the axial direction of the screw as the workpiece W is roughly consistent with the Y direction. Fig. 20 Although not shown in the figure, in the height image, it is shown by the continuous change of color from the low part to the high part of the workpiece W, for example, the change from the low side to the high side is blue, green, yellow, orange, red, etc. In addition, invalid pixels are shown by black, etc.

[0192] In the first screen 510, an X-coordinate indication line 512 indicating an X-coordinate and a first Y-coordinate indication line 513 and a second Y-coordinate indication line 514 indicating a Y-coordinate are displayed. The horizontal direction of the first screen 510 is the X-direction, so the X-coordinate indication line 512 is composed of a straight line extending in the vertical direction. The X-coordinate indication line 512 can be moved to any position in the X-direction by operating the operation unit 3B by the user.

[0193] In addition, the longitudinal direction of the first screen 510 is the Y direction, so the first Y coordinate indication line 513 and the second Y coordinate indication line 514 are composed of straight lines extending in the horizontal direction. The first Y coordinate indication line 513 and the second Y coordinate indication line 514 are parallel to each other. In addition, the first Y coordinate indication line 513 and the second Y coordinate indication line 514 are orthogonal to the X coordinate indication line 512.

[0194] The screen generator 38 can acquire the X coordinate in the height image displayed on the first screen 510. When the X coordinate indication line 512 displayed on the first screen 510 is moved in the X direction by the user operating the operation unit 3B, the screen generator 38 can specify the X coordinate in the height image based on the position of the X coordinate indication line 512 after the movement in the X direction. By specifying the X coordinate in the height image, the screen generator 38 acquires the YZ cross-sectional profile of the workpiece W corresponding to the X coordinate in the height image and displays the YZ cross-sectional profile on the second screen 520. The method of specifying the X coordinate in the height image is not limited to the method using the X coordinate indication line 512, and for example, a method of specifying using a dot, an arrow, etc. may be used. The setting screen 530 may first display the first screen 510, and when the X coordinate is specified in the first screen 510, the first screen 510 is switched to the second screen 520 for display.

[0195] In the second screen 520 of the setting screen 530, a second coordinate system display unit 521 indicating the Y direction and the Z direction is provided. The second screen 520 shows the measurable range of the imaging unit 13. Specifically, the white portion in the second screen 520 is the measurable range of the imaging unit 13, and the black portion in the second screen 520 is the range that cannot be measured by the imaging unit 13 (outside the measurable range). As described above, the measurable range of the imaging unit 13 is roughly arc-shaped, so the white portion in the second screen 520 is also roughly arc-shaped. Fig. 20 The coloring of white and black in is an example, and any color can be used as long as it can distinguish between the inside and outside of the measurable range. In addition, as a display method of the measurable range, in addition to the method of changing the color within the measurable range and outside the measurable range, it can also be a method of showing the inside and outside of the measurable range by changing the color density, and it can also be a method of showing the inside and outside of the measurable range by characters, symbols, boundary lines, etc. By displaying the measurable range in the second screen 520, the user can easily determine where the acquisition range can be set just by observing the second screen 520.

[0196] In the second screen 520, a Y-direction reference line 522 indicating a reference distance in the Y direction and a Z-direction reference line 523 indicating a reference distance in the Z direction are displayed. The Y-direction reference line 522 is composed of a straight line extending in the horizontal direction of the second screen 520, and the Z-direction reference line 523 is composed of a straight line extending in the vertical direction of the second screen 520. Therefore, the Y-direction reference line 522 and the Z-direction reference line 523 are orthogonal to each other, and the intersection of the Y-direction reference line 522 and the Z-direction reference line 523 indicates the center of the field of view of the optical displacement meter 1.

[0197] In the second screen 520 , an accuracy guarantee region can also be displayed as a region for guaranteeing a certain level of measurement accuracy or higher. Fig. 20 The line 524 in the figure is a line indicating the boundary between the accuracy guaranteed area and the area outside the area. The area to the right of the line 524 is the accuracy guaranteed area, and the area to the left of the line 524 is outside the accuracy guaranteed area. By displaying the accuracy guaranteed area in the second screen 520 in this way, the user can easily determine whether the workpiece W is within the measurement range where sufficiently high measurement accuracy can be obtained by simply viewing the second screen 520.

[0198] The setting screen 530 can accept the setting of the acquisition range for obtaining the measurement results through the second screen 520. Fig.21 As shown, the acquisition range can be set to a rectangle, for example. In the case of a rectangle, the YZ coordinates (Y 0 , Z 0 )、(Y 1 , Z 1 )、(Y 2 , Z 2 )、(Y 3 , Z 3 ). Points P0, P1, P2, and P3 are points used to determine the vertices of the rectangle. The area obtained by connecting points P0, P1, P3, and P4 with four straight lines 541, 542, 543, and 544 is the acquisition range. Fig.18 By operating the operation unit 3B shown in the figure, the point P0, point P1, point P2, and point P3 can be moved to any position on the second screen 520, so that the shape, size, and position of the acquisition range on the second screen 520 can be arbitrarily set. Point P0, point P1, point P2, and point P3 can be moved by the operation unit 3B, and straight lines 541, 542, 543, and 544 can also be moved by the operation unit 3B. In addition, the acquisition range can be a circle, an ellipse, or an area surrounded by a free curve in addition to a rectangle, and can be set to any shape on the YZ plane. Regardless of the shape, the setting of the acquisition range can be accepted through the second screen 520.

[0199] The signal processing unit 32 transforms the YZ coordinates used to define the acquisition range into V coordinates and a rotation angle based on the prescribed transformation conditions, and determines the rotation angle range of the light-projecting and light-receiving module 10 based on the rotation angle. When determining the rotation angle range of the light-projecting and light-receiving module 10, first, the signal processing unit 32 obtains the setting for the acquisition range received with the help of the second screen 520. In this example, the acquisition range is a rectangle, so the signal processing unit 32 obtains the YZ coordinates of the four points P0, P1, P2, and P3 used to define the acquisition range. After obtaining the YZ coordinates of the points P0, P1, P2, and P3 that constitute the acquisition range, the signal processing unit 32 transforms them into V coordinates and a rotation angle based on the prescribed transformation conditions (in Fig. 22 Then, the signal processing unit 32 determines the rotation angle range (in Fig.23 In this example, from θ 0 to θ 1 The YZ coordinates of each point can be converted into V coordinates and rotation angles by, for example, inverse transformation of linear correction when calculating the measured value.

[0200] The imaging control unit 13b sets the output area of ​​the light receiving amount distribution in the image sensor 13a based on the rotation angle. Fig.24 As shown, as a premise, in the optical displacement meter 1 that measures the cross-sectional profile based on the principle of triangulation as in the present embodiment, the distance in the actual space corresponding to one pixel on the image sensor 13a is different between the near side and the far side, and the distance represented by one pixel on the far side is longer. In addition, the number of pixels (pixels) in the V direction required when measuring a constant Z range (mm) also changes depending on the rotation angle of the light-emitting and light-receiving module 10.

[0201] If we assume that the number of pixels in the V direction is constant, then Fig.25 As shown in the area marked with mark 528. In this way, if a constant number of pixels is continuously obtained for the V direction of the image sensor 13a within the rotation angle range of the light projecting and light receiving module 10, the measurement range in the Z direction becomes a complex shape when observing the YZ plane, so it is difficult for the user to handle. Specifically, the measurable Z direction height varies depending on the position in the Y direction, so when the workpiece W of the same height moves in the field of view, there are situations where it can be measured and situations where it cannot be measured. For example, the workpiece W can be measured during the setup adjustment before the use of the optical displacement meter 1, so the use is started while maintaining this state, but when the position of the workpiece W during operation is configured at a position different from that during the setup adjustment, the workpiece W may not be measured, and rework is required.

[0202] In contrast, the camera control unit 13b calculates the number of pixels required at each rotation angle to dynamically switch the acquisition range of the image sensor 13a, thereby adjusting the acquisition start position and the acquisition end position in the Z direction to be flat when viewed on the YZ plane. That is, the image sensor 13a outputs only the light receiving amount distribution of the pixel group included in the acquisition range among the multiple pixels at each rotation angle corresponding to each shooting timing within the rotation angle range of the light projecting and light receiving module 10. At this time, the image sensor 13a changes the pixel range of the pixel group used to output the light receiving amount distribution in the V direction at each rotation angle corresponding to each shooting timing based on the prescribed conversion conditions, so that the change in the Z direction height of the acquisition range is suppressed within the rotation angle range of the light projecting and light receiving module 10.

[0203] like Fig.26 As shown in FIG. 5 , by reducing the number of pixels acquired in the V direction in the lower part of the region 528 and not reducing the number of pixels acquired in the V direction in the upper part of the region 528, it is possible to adjust the acquisition start position and the acquisition end position in the Z direction to be flat when viewed on the YZ plane. The adjusted region is indicated by a mark 529. Not only by changing the number of pixels acquired in the V direction of the image sensor 13a, but also by changing the acquisition start position and the acquisition end position in the Z direction, the same adjustment can be performed.

[0204] As described above, the number of pixels obtained from the image sensor 13a can also be changed directly, but as a modified example, the number of pixels obtained from the image sensor 13a can be set constant instead of being changed directly, and the range to be masked can be adjusted in the subsequent processing. In this case, in the image sensor 13a, the pixel range in the V direction of the pixel group used to output the light receiving amount distribution within the rotation angle range of the light projection and light receiving module 10 is fixed. The signal processing unit 32 determines the rows to be masked in the light receiving amount distribution output from the pixel group of the image sensor 13a at each rotation angle corresponding to each shooting timing based on the prescribed transformation conditions, so that the change in the Z direction height of the acquisition range is suppressed within the rotation angle range of the light projection and light receiving module 10. Through this modified example, it is also possible to set a measurement range that can be handled by the user.

[0205] As described above, even in the acquisition range of the same size in the XYZ space, the number of acquired pixels of the image sensor 13a in the V direction is different. The change in the number of acquired pixels affects the time required for the output processing of the light receiving amount distribution output from the image sensor 13a, and sometimes becomes the speed-limiting stage of the entire processing. In this case, Fig. 27 As shown, by moving the acquisition range 550 in a manner that maintains the same size in the XYZ space, the overall processing rhythm changes. Fig. 27The white area in the figure shows the measurable range of the optical displacement meter 1. Fig. 27 In the figure on the left side of FIG. , the acquisition range 550 is located at the lower side of the measurable range, but when making it Fig. 27 When the image sensor 13a moves to the upper side of the measurable range as shown in the right figure, the time (output time) required for output processing of the light receiving amount distribution from the image sensor 13a becomes longer by, for example, 0.2 seconds.

[0206] As described above, there is a correspondence between the position of the acquisition range 550 and the output time, but this correspondence is inconvenient in the use case where the setting is performed in a state where the rhythm of the device is determined. In view of this, in this embodiment, the Z-direction height of the acquisition range is automatically changed so that when the acquisition range 550 is moved, the difference in output time before and after the movement becomes smaller or no longer exists.

[0207] That is, in Fig.28 , the second screen 520 of the setting screen 500 is shown, and the setting screen 500 receives instructions for translation of the acquisition range through the second screen 520. For example, when the acquisition range is a rectangle, the user can operate the operation unit 3B to move the four points used to define the acquisition range in the up-down direction and the left-right direction of the second screen 520, thereby receiving instructions for translation of the acquisition range. Fig.28 In the figure on the left side of FIG. , the acquisition range 550 is located at the lower side of the measurable range, but it can be made as Fig.28 As shown in the figure on the right side of the diagram, the image is shifted to the upper side of the measurable range.

[0208] The signal processing unit 32 changes the Z-direction height of the acquisition range 550 before and after the translation based on a predetermined transformation condition, so as to suppress the difference between the output time of the light receiving amount distribution output from the pixel group included in the acquisition range 550 before the translation of the acquisition range 550 and the output time of the light receiving amount distribution output from the pixel group included in the acquisition range 550 after the translation of the acquisition range 550. Fig.28 As shown, when the output time of outputting the light receiving amount distribution from the pixel group included in the acquisition range 550 before the acquisition range 550 is shifted is set to 1.0 second, Fig.28The Z-direction height of the acquisition range 550 shown on the right side of becomes lower, so that the output time of the light receiving amount distribution output from the pixel group included in the acquisition range 550 after the translation can be set to 1.0 second. Therefore, when setting is performed in a state where the rhythm of the device has been determined, even if the acquisition range 550 is moved, the output time of the light receiving amount distribution output from the image sensor 13a does not change, so it can be easily set. In addition, the output time before the translation of the acquisition range 550 and the output time after the translation may not be strictly the same, as long as the Z-direction height of the acquisition range 550 is changed so that the difference in output time before and after the translation becomes smaller. In addition, it is also possible to accept the adjustment of the Z-direction height of the acquisition range 550 by the user after the Z-direction height of the acquisition range 550 is automatically changed.

[0209] It is sometimes difficult to set the acquisition range when it is unknown at which part of the measurement range the workpiece W is disposed. In this case, in the present embodiment, regardless of the setting of the acquisition range at the current time point, three-dimensional measurement is performed over the entire maximum swing range of the light-emitting and light-receiving module 10. Specifically, the motor control unit 30 causes the light-emitting and light-receiving module 10 to swing within a setting angle range that is wider than the rotation angle range corresponding to the acquisition range. Thus, the light-emitting and light-receiving module 10 acquires the setting YZ cross-sectional profile corresponding to the setting angle range. Fig.29 As shown, the screen generation unit 38 generates a screen showing the setting YZ cross-sectional profile in the second screen 520. The setting YZ cross-sectional profile includes the YZ cross-sectional profile of the acquisition range and includes the YZ cross-sectional profile of a wider range than the acquisition range. By allowing the user to observe the YZ cross-sectional profile of the wide range, the acquisition range can be easily set.

[0210] (Process of obtaining range setting)

[0211] Fig.30 : is a flowchart showing the process of obtaining the range setting process. In step SA1, the motor control unit 30 drives the motor 20 to move the light-projecting and light-receiving module 10 to the measurement start position. In step SA2, the motor control unit 30 drives the motor 20 to swing the light-projecting and light-receiving module 10, and at the same time, the light-projecting unit 11 emits the slit light S1, and the camera unit 13 obtains a plurality of light-receiving images. The imaging can be at equal time intervals, equal encoder intervals, or equal spacing intervals in the Y direction corresponding to a certain distance in the Z direction. In step SA3, the camera unit 13 generates a light-receiving image at each equal time interval or equal encoder interval.

[0212] In step SA4, the signal processing unit 32 calculates the peak position in the V direction at each U position of each light-receiving image. In step SA5, the UV coordinates of the peak positions obtained in the process of step SA4 are associated with θ corresponding to the light-receiving image to generate a set of UVθ. In step SA6, UVθ is transformed into XYZ coordinates. The transformation to XYZ coordinates can be performed based on the prior calibration information. Here, the peak position obtained in the process of step SA4 sometimes includes a true peak position and a false peak position caused by noise such as multiple reflections. It is also possible to perform a process of removing the false peak position from the UV coordinates in step SA4, or to perform a process of removing the false peak position from the XYZ coordinates after the conversion into XYZ coordinates including the false peak position in step SA6. In addition, in step SA6, XY equal interval correction can also be performed. That is, the signal processing unit 32 can calculate the corrected Z coordinate corresponding to the corrected XY coordinate by performing equal interval correction on the XY coordinates. The signal processing unit 32, for example, creates a Z column with equal intervals of X coordinates based on the (X, Z) column after contour adjustment. When obtaining interpolation points when creating the Z column, first, valid points before and after the XZ contour can be determined, and interpolation points can be obtained based on these valid points by linear interpolation. By performing equal interval correction in the Y direction in the same manner, the corrected Z coordinates after equal interval correction in both the X direction and the Y direction can be calculated. The height image output unit 37 outputs a height image based on the corrected XYZ coordinates obtained by the equal interval correction. By performing XY equal interval correction, it is easy to perform subsequent image processing and also easy to visualize.

[0213] In step SA7 , the screen generator 38 generates a setting screen 500 including a first screen 510 showing the height image and a second screen 520 showing the YZ cross-sectional profile at an arbitrary X position in the height image, and displays the setting screen 500 on the display unit 3A.

[0214] In step SA8, the designation of the X position in the height image is received through the first screen 510 displayed in step SA7. In step SA9, the screen generator 38 displays the YZ cross-sectional profile corresponding to the X position designated in step SA8 on the second screen 520. In step SA10, the signal processor 32 receives the designation of the acquisition range (a plurality of YZ coordinate sets) from the YZ cross-sectional profile. In step SA11, the signal processor 32 performs the inverse transformation from UVθ to XYZ, thereby transforming the plurality of YZ coordinate sets into θV, respectively.

[0215] In step SA12, the signal processing unit 32 determines the rotation angle range of the light-projecting and light-receiving module 10 based on θV acquired in step SA11. In step SA13, the number of pixels in the V direction obtained from the image sensor 13a is determined for each rotation angle of the light-projecting and light-receiving module 10. When the number of pixels in the V direction is determined for each rotation angle of the light-projecting and light-receiving module 10, for example, it can be calculated based on information of a conversion table for converting UVθ into XYZ coordinates. In addition, it is not limited to the number of pixels, as long as the pixel range in the V direction obtained from the image sensor 13a is determined.

[0216] In step SA14, the signal processing unit 32 determines whether the acquisition range is shifted ( Fig.28 ). If the acquisition range is shifted, the process proceeds to step SA15, where the Z-direction height of the acquisition range is adjusted so that the output time before and after the shift (the number of pixels in the V-direction of the acquisition range) is constant, and the adjusted acquisition range is presented to the user.

[0217] (Display of received light image)

[0218] In this embodiment, the light-receiving image can also be displayed on the display unit 3A. For example, in order to ensure the accuracy of the three-dimensional measurement of the optical displacement meter 1 or adjust the settings of the optical displacement meter 1, it is sometimes desirable to observe the light-receiving image of the image sensor 13a when acquiring an arbitrary cross section. In this case, the arbitrary cross section can be easily acquired by moving the light-projecting and light-receiving module 10 to the desired position.

[0219] Next, the structure that enables the light-receiving image to be displayed on the display unit 3A will be specifically described. The screen generating unit 38 generates a screen image by acquiring the light-receiving amount distribution output from the image sensor 13a. Fig.31 The screen 600 shown in FIG. 600 is different from the screen 600 in that it shows a height image. Fig. 20 The first screen 510 is common to the height image. The screen 600 is used to accept the designation of a point in the height image. For example, the user can operate the operation unit 3B to arrange the point 600a at any position on the height image displayed on the screen 600. By arranging the point 600a, the designation of a point in the height image can be accepted.

[0220] The signal processing unit 32 obtains the rotation angle of the light-projecting and light-receiving module 10 corresponding to the XYZ coordinates of a point (point 600a) based on the above-mentioned predetermined conversion conditions. The motor control unit 30 controls the motor 20 to move the light-projecting and light-receiving module 10 to a position corresponding to the rotation angle obtained by the signal processing unit 32. The light-projecting and light-receiving module 10 obtains a light-receiving image at a position corresponding to the rotation angle. The screen generation unit 38 generates a screen 601 showing the light-receiving image and displays the screen 601 on the display unit 3A.

[0221] The signal processing unit 32 can also obtain the pixel range in the V direction corresponding to the rotation angle of the light-emitting and light-receiving module 10 based on the prescribed conversion conditions. In this case, the screen generation unit 38 can display the light-receiving image that specifies the light-receiving amount distribution corresponding to the pixel range in the V direction. The motor control unit 30 can move the light-emitting and light-receiving module 10 to the rotation angle at which the light-receiving image is obtained in the process of generating the height image.

[0222] The user can also specify the rotation angle of the light-emitting and light-receiving module 10. Fig.18 and Fig.31 As shown in FIG. 1 , the optical displacement meter 1 includes a rotation angle designation unit 3C for accepting designation of a rotation angle of the light-emitting and light-receiving module 10. The rotation angle designation unit 3C can accept designation of a rotation angle of the light-emitting and light-receiving module 10 by the user designating a profile number in the measurement range of the light-emitting and light-receiving module 10. As an example, in Fig.31 , the 613th contour number among all 800 contours is specified. The contour numbers can be numbered in the order in which the contours are acquired. In this case, there is no need for a height image for specifying the rotation angle, and there is also a case where the height image is not generated originally, so the screen generation unit 38 can also omit the screen 600 and only generate the screen 601. The screen generation unit 38 displays the light-receiving image corresponding to the rotation angle specified by the rotation angle specifying unit 3C on the display unit 3A. Specifically, when a change in the rotation angle of the light-projecting and light-receiving module 10 is accepted, the motor control unit 30 controls the motor 20 to move the light-projecting and light-receiving module to the changed rotation angle, and displays the light-receiving image captured by the image sensor 13a at the moved position on the display unit 3A. In addition, by specifying the coordinates (X, Y, Z) of any point on the height image, it is possible to calculate any section containing the coordinates using the same logic as the inverse transformation of the above-mentioned linear correction. In this way, it is possible to accurately observe a section where noise is generated, for example.

[0223] (Flow of displaying received light images)

[0224] Fig.32 FIG. 4 is a flowchart showing an example of the flow of display processing of the light-receiving image. Steps SB1 to SB6 are respectively Fig.30 The steps SA1 to SA6 are the same. In step SB7, the screen generation unit 38 displays the height image on the display unit 3A. In step SB8, the signal processing unit 32 accepts the designation of a point in the height image displayed in step SB7. In step SB9, the signal processing unit 32 transforms the XYZ coordinates of the accepted point into UVθ. In step SB10, the motor control unit 30 drives the motor 20 to move the light projection and light receiving module 10 to θ acquired in step SB9.

[0225] In step SB11, the motor control unit 30 stops the light-emitting and light-receiving module 10 at the position to which it has moved, and the camera unit 13 acquires the light-receiving image in the stopped state. In step SB12, the screen generation unit 38 displays the light-receiving image acquired in step SB11 on the display unit 3A. For example, it is also possible to consider storing the light-receiving image in association with θ in step SB2, and reading the light-receiving image corresponding to the acquired θ in the later stage, but if all the light-receiving image information is stored, the amount of information is too large and a huge memory is required, so the image is re-shot in step SB11.

[0226] (Housing structure)

[0227] like Fig.33 As shown in FIG. 1 , the dimensions required for the outer shape of the housing 40 are determined according to the field of view of the optical system 11b. In addition, since there is a viewing angle in the optical system 11b, there is a width of the field of view that has a certain inclination relative to the optical axis, such as Fig.33 As shown, if the outer shape of the housing 40 is a simple rectangular parallelepiped shape to satisfy the field of view, a region (hatched portion) that is wasted in volume will be generated.

[0228] In contrast, as in Fig.34 As shown as a first example in FIG. 1 , in the present embodiment, a shape is set such that one side of the shell 40 in the thickness direction is partially cut off, thereby setting the shell 40 to eliminate the area of ​​waste in volume. That is, when the thickness direction of the shell 40 is set to the X direction, a difference in thickness can be set between the end of the shell 40 on the side of the irradiation direction of the slit light and the end of the shell 40 on the side opposite to the irradiation direction. Specifically, the shell 40 can be set to the following shape: the end on the side of the irradiation direction of the slit light has a first thickness in the X direction, and the end on the side opposite to the irradiation direction has a second thickness in the X direction that is smaller than the first thickness. In this way, by making the end of the shell 40 on the side opposite to the irradiation direction relatively thin, the area of ​​waste in volume can be eliminated or reduced.

[0229] In addition, as in Fig.35 As shown as a second example in FIG. 4 , the shape may be such that both sides in the thickness direction of the housing 40 are partially cut away. Thereby, the region that is wasted in volume can be further reduced.

[0230] Industrial Applicability

[0231] As described above, the optical displacement meter according to the present disclosure can be used, for example, when acquiring data on the three-dimensional shape of a workpiece.

[0232] Description of Reference Numerals

[0233] 1: optical displacement meter; 3A: display unit; 3C: rotation angle specifying unit; 10, 100: light projecting and light receiving module; 11: light projecting unit; 12: light receiving lens; 13: camera unit; 20: motor; 30: motor control unit; 32: signal processing unit; 36: rotation angle acquiring unit; 37: height image output unit; 38: screen generating unit; 40, 400: housing; 52: encoder; 61, 62: stopper; W: workpiece.

Claims

1. An optical displacement meter, characterized in that: have: A light-projecting and light-receiving module, comprising a light-projecting unit, a light-collecting unit, a camera unit, and a supporting member, wherein the light-projecting unit irradiates slit light extending in the X direction, the light-collecting unit comprises a light-receiving lens for converging reflected light obtained by reflection from a workpiece, the camera unit receives the light concentrated by the light-collecting unit, and the supporting member integrally holds the light-projecting unit, the light-collecting unit, and the camera unit in a sham relationship in which a light-receiving surface of the camera unit is inclined relative to an optical axis of the light-receiving lens; A motor, which rotates the light-projecting and light-receiving modules integrally; A housing for accommodating the light projecting and receiving module; and The control unit controls the motor to rotate the light projecting and receiving module in the housing while maintaining the Sham relationship, thereby scanning the slit light in a direction perpendicular to the X direction.

2. The optical displacement meter according to claim 1, characterized in that: The rotation axis of the light projecting and light receiving module is arranged so as to substantially coincide with the center of gravity of the light projecting and light receiving module on a YZ plane orthogonal to the X direction.

3. The optical displacement meter according to claim 1, characterized in that: The light projecting part and the light focusing part of the light projecting and light receiving module are arranged at a distance from each other in the radial direction of the rotation axis of the light projecting and light receiving module, and the light focusing part is configured to be heavier than the light projecting part. A counterweight is provided at a position in the light-projecting and light-receiving module that is closer to the light-projecting part than to the light-focusing part, so as to suppress the deviation of the center of gravity position of the light-projecting and light-receiving module from the rotation axis due to the difference in weight between the light-projecting part and the light-focusing part on the YZ plane orthogonal to the X direction.

4. The optical displacement meter according to claim 1, characterized in that: The light projecting unit includes a light source and a light source housing for accommodating the light source. The light focusing unit further comprises a lens housing for accommodating the light receiving lens. The light projecting part and the light focusing part of the light projecting and light receiving module are arranged at a distance from each other in the radial direction of the rotation axis of the light projecting and light receiving module, and the volume of the light source housing is configured to be smaller than the volume of the lens housing. The light source housing is made of a material having a higher density than that of the lens housing, so as to suppress the deviation of the center of gravity of the light projecting and receiving module from the rotation axis due to the weight difference between the light projecting unit and the light focusing unit in the YZ plane orthogonal to the X direction.

5. The optical displacement meter according to claim 1, characterized in that: The light-projecting and light-receiving module further includes a reflecting member, which is arranged on the optical path of the light collected by the focusing unit and reflects the collected light toward the imaging unit, so that the distance from the rotation axis of the light-projecting and light-receiving module to the imaging unit becomes shorter. The supporting member integrally holds the reflecting member together with the light projecting unit, the light collecting unit, and the imaging unit so as to have the sham relationship.

6. The optical displacement meter according to claim 1, characterized in that: The light-projecting and light-receiving module further comprises a reflecting member, which is arranged on the optical path of the reflected light obtained by the workpiece, and reflects the reflected light toward the focusing unit, so that the distance from the rotation axis of the light-projecting and light-receiving module to the focusing unit becomes shorter. The supporting member integrally holds the reflecting member together with the light projecting unit, the light collecting unit, and the imaging unit so as to have the sham relationship.

7. The optical displacement meter according to claim 5 or 6, characterized in that: The rotation axis of the light projecting and receiving module is disposed between the light projecting unit and the reflecting member when viewed along the rotation axis.

8. The optical displacement meter according to claim 1, characterized in that: The rotation axis of the light projecting and receiving module is arranged at a position overlapping with the light focusing unit when viewed along the rotation axis, or is arranged between the light projecting unit and the light focusing unit.

9. The optical displacement meter according to claim 1, characterized in that: A bearing is also provided, the bearing supporting the rotating shaft of the light projecting and receiving module, The bearing supports a moment load generated by a difference in position between a portion of the rotating shaft supported by the bearing and the center of gravity of the light projecting and receiving module.

10. The optical displacement meter according to claim 1, characterized in that: It also includes an optical encoder for detecting the rotation angle of the rotation axis of the light projecting and receiving module. The optical encoder is accommodated in a closed space in the housing to prevent foreign matter from entering from outside the housing and to prevent foreign matter from entering from a space in which the light projecting and light receiving module is accommodated and rotated.

11. The optical displacement meter according to claim 1, characterized in that: When the light projecting and light receiving module is assumed to rotate to a first rotation angle, the light projecting and light receiving module has a size that contacts the inner wall of the housing on a YZ plane orthogonal to the X direction. The rotation angle range of the projecting and receiving light module that rotates during measurement is set to a predetermined angle range that is smaller than the first rotation angle so as to avoid contact between the projecting and receiving light module and the inner wall of the housing.

12. The optical displacement meter according to claim 11, characterized in that: The control unit controls the motor so as to avoid contact between the light projecting and light receiving module and the inner wall of the housing by rotating the light projecting and light receiving module within the predetermined angle range during measurement.

13. The optical displacement meter according to claim 11, characterized in that: A stopper is disposed inside the housing, and the stopper is used to prevent the light projecting and receiving module from rotating to the first rotation angle outside the specified angle range and contacting with the inner wall of the housing.

14. The optical displacement meter according to claim 1, characterized in that: The housing has a first thickness in the X direction at an end portion on the irradiation direction side of the slit light, The housing has a second thickness in the X direction that is smaller than the first thickness at an end portion on the opposite side to the irradiation direction.

Images