Optical displacement meter

Abstract

Provided is an optical displacement meter capable of measuring displacement at all rotation angles of a light projection / reception system even when a reading region of an image sensor is limited. An optical displacement meter (1) is provided with: a light projection unit that emits slit light extending in the X direction; an image sensor that receives the light focused by the light receiving lens; a light projecting / receiving module that integrally holds the light projecting unit, the light receiving lens, and the image sensor; a motor that rotates the light projecting and receiving module; a control unit that controls the motor to rotate the light projecting / receiving module so as to scan the slit light in a direction orthogonal to the X direction; and a calculation unit that generates, at different positions in the scanning direction, a cross-sectional profile indicating a height in the Z direction, respectively, on the basis of the pixel signals read from the image sensor. The calculation unit is configured so as to be able to change a local region, which is a target for reading a pixel signal of the image sensor, in accordance with the rotation angle.

Description

[0001] This application is a divisional application of an application with the application date of June 17, 2024, the application number of 202410774149.9, and the invention name of "Optical displacement meter". TECHNICAL FIELD

[0002] The present disclosure relates to an optical displacement meter that measures displacement of a workpiece using light. BACKGROUND

[0003] As an optical displacement meter, an optical displacement meter configured as follows is known: for example, a slit light extending in an X direction is irradiated to a workpiece, and reflected light obtained by reflection of the slit light by a surface of the workpiece is received by an image sensor, whereby an XZ cross-sectional profile can be acquired. By acquiring a plurality of XZ cross-sectional profiles at different positions in a Y direction of the workpiece, data of a three-dimensional shape of the workpiece can be generated, but in this case, a conveyor for carrying the workpiece in the Y direction, a linear motion mechanism or the like for moving the displacement meter body relative to the workpiece in the Y direction, and the like are required, and it is sometimes difficult to introduce.

[0004] In contrast, a configuration is known in which, for example, a light projection system for projecting a slit light and a light reception system for receiving reflected light (collectively referred to as a light projection and reception system) are configured to be rotatable, and the light projection and reception system is caused to rotate so that the slit light can scan the workpiece in the Y direction.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT LITERATURE

[0007] Patent Literature 1: European Patent Publication No. 3232152

[0008] Patent Literature 2: Chinese Utility Model Registration No. 210664364 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] In addition, in a case where the same height portion of the workpiece is measured using a linear motion mechanism or the like for moving the displacement meter body relative to the workpiece in the Y direction, even in a plurality of XZ cross-sectional profiles obtained at different positions in the Y direction of the workpiece, the peak position in the V direction (a direction corresponding to the Z direction of the workpiece) on the image sensor is the same. In this case, by limiting the reading region of the image sensor to a portion corresponding to the height range of the workpiece, it is possible to achieve high speed of measurement.

[0011] However, in a case where a plurality of cross-sectional profiles are acquired for a stationary workpiece by rotating the light-receiving system as in Patent Documents 1 and 2, the measurement region is in the shape of a circular arc centered on the rotation axis. Therefore, there is a problem that even for the same height of the workpiece, the peak position in the V direction of each profile varies depending on the rotation angle of the light-receiving system, and thus if the reading region of the image sensor is fixed for the purpose of measurement speedup, displacement cannot be measured at all rotation angles of the light-receiving system.

[0012] The present disclosure was made in view of the above-described problems, and aims to enable measurement of displacement at all rotation angles of a light-receiving system even in a case where the reading region of an image sensor is limited, in an optical displacement meter that measures displacement by rotating the light-receiving system.

[0013] Solution to the problem

[0014] To achieve the above-described object, in the present embodiment, an optical displacement meter that measures displacement of a workpiece using light can be assumed. The optical displacement meter is a light-section type optical displacement meter that measures a cross-sectional profile of a workpiece having a height in the Z direction based on the principle of triangulation, and includes: a light projecting section that projects slit light extending in the X direction toward the workpiece; a light receiving lens that converges reflected light obtained by reflection by the workpiece; an image pickup section that has an image sensor that receives the reflected light converged by the light receiving lens and a camera control section that controls the image sensor; a motor that rotates a light-receiving module having the light projecting section, the light receiving lens, and the image pickup section as a unit; a control section that controls the motor to cause the slit light to scan in a direction orthogonal to the X direction; and a signal processing section that generates the cross-sectional profile at each rotation angle of the motor based on the amount of light received by the image sensor, wherein a measurable range in the shape of a substantially circular arc having a prescribed depth centered on a rotation axis of the image pickup section is formed by rotation of the light-receiving module, and a partial region used to read the amount of light of the image sensor corresponding to each rotation angle dynamically changes in correspondence with the rotation angle.

[0015] According to this structure, when the light-emitting and light-receiving modules are rotated as a whole by a motor, the slit light extending along the X direction scans the workpiece in a direction orthogonal to the X direction, forming a roughly arc-shaped measurable range with a predetermined depth centered on the rotation axis of the camera unit. At this time, in order to achieve high speed, instead of reading the light received from the entire camera unit, a local area is set for reading the light received. Therefore, the measurement range varies depending on the rotation angle, and even the same local area captures different heights (Z direction) of the workpiece. Thus, by dynamically changing the local area in accordance with each rotation angle corresponding to the measurement range that varies according to each rotation angle, it is possible to acquire multiple cross-sectional profiles at different positions of the workpiece and generate three-dimensional shape data of the workpiece at high speed without the need for equipment such as a conveyor for moving the workpiece along the Y direction or a linear motion mechanism for moving the displacement gauge body relative to the workpiece along the Y direction.

[0016] The effects of the invention

[0017] As explained above, the local area that is the object of reading the pixel signal of the image sensor can be changed in accordance with the rotation angle of the light-projecting part, the light-receiving lens and the image sensor. Therefore, even when the reading area of ​​the image sensor is limited for the purpose of high-speed measurement, displacement can be measured at all rotation angles of the light-projecting and light-receiving system. Attached Figure Description

[0018] Figure 1 This is a diagram illustrating the application of the optical displacement meter according to Embodiment 1 of the present invention.

[0019] Figure 2 This is a perspective view obtained from above, showing the optical displacement meter according to Embodiment 1 of the present invention.

[0020] Figure 3 This is a perspective view obtained from below, showing the optical displacement meter according to Embodiment 1 of the present invention.

[0021] Figure 4 This is a top view showing the interior of the upper space of the optical displacement meter according to Embodiment 1 of the present invention.

[0022] Figure 5 This is a top view of the light-emitting and light-receiving module of the optical displacement meter according to Embodiment 1 of the present invention.

[0023] Figure 6 This is a block diagram illustrating the structure of the optical displacement meter according to Embodiment 1 of the present invention.

[0024] Figure 7 yes Figure 2 Sectional view along line VII-VII.

[0025] Figure 8 yes Figure 2 The cross-sectional view of line VIII-VIII.

[0026] Figure 9 This is a diagram illustrating the method for displacement measurement.

[0027] Figure 10 This is a diagram illustrating an example of measuring the displacement of a workpiece with surfaces at the same height.

[0028] Figure 11 This is a diagram illustrating an example of how the position of a local region in an image sensor can be varied in the V direction.

[0029] Figure 12 This is a diagram illustrating an example of measuring the displacement of a workpiece whose surface height varies depending on its location.

[0030] Figure 13 This is the variation of implementation 1 involving the same... Figure 5 A fairly accurate diagram.

[0031] Figure 14 This is the variation of implementation 1, example 2, involving the same... Figure 4 A fairly accurate diagram.

[0032] Figure 15 This is a diagram obtained by observing the internal structure of the optical displacement meter involved in the variation 2 of embodiment 1 from the bottom.

[0033] Figure 16 This is related to Implementation Method 2. Figure 2 A fairly accurate diagram.

[0034] Figure 17 This is a diagram obtained by viewing the internal structure of the optical displacement meter involved in Embodiment 2 from above.

[0035] Figure 18 This is related to Implementation Method 2. Figure 7 A fairly accurate diagram.

[0036] Figure 19 This is a variation of implementation method 2 involving the following: Figure 17 A fairly accurate diagram. Detailed Implementation

[0037] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Furthermore, the following description of preferred embodiments is merely illustrative and is not intended to limit the invention, its applications, or its uses.

[0038] (Implementation Method 1)

[0039] Figure 1 This diagram illustrates the application of the optical displacement meter 1 according to Embodiment 1 of the present invention. The optical displacement meter 1 is an example of a light-sectioning optical displacement meter: using a slit light S1, it measures the cross-sectional profile of a workpiece W (the object being measured) having height in the Z direction based on the principle of triangulation. In this embodiment, an example is described where the inspection system S consists of the optical displacement meter 1, the controller 2, and a personal computer PC; however, the system is not limited to this structure, and the inspection system S may include, for example, a PLC (programmable logic controller).

[0040] Before using the inspection system S, various inspection settings can be made, for example, via the controller 2 and the personal computer PC. During operation after setting, the optical displacement meter 1 measures the displacement of the workpiece W at a pre-defined time. Data representing the measurement results is sent from the optical displacement meter 1 to the controller 2 and the personal computer PC, thereby performing an inspection based on the inspection settings. Data representing the measurement results of the optical displacement meter 1, inspection results, etc., can be stored in the controller 2 and the personal computer PC.

[0041] In use, it can also be used without the controller 2 and the personal computer PC, solely through the optical displacement meter 1, and is not limited to... Figure 1 The application method shown is as follows. In addition, in the following description, the inspection system S including the optical displacement meter 1 will be described, but the present invention can also be applied in the case of using only the optical displacement meter 1, or in the case of using a system obtained by combining the optical displacement meter 1 with a PLC.

[0042] Inspection system S is a system that performs online visual inspection of workpiece W. In online visual inspection, for example, in a site where multiple workpieces W are sequentially transported, the visual inspection of workpiece W is performed sequentially. Figure 1 The X, Y, and Z directions of workpiece W are defined as shown. When viewed from above, the X and Y directions are orthogonal to each other. The Z direction is the height direction of workpiece W, which is orthogonal to both the X and Y directions. Alternatively, the X direction of workpiece W can be called its depth direction, and the Y direction its width direction; however, this is just one example, and the definitions of the X, Y, and Z directions of workpiece W are arbitrary.

[0043] The height data of workpiece W can be obtained using the optical displacement meter 1, therefore, the appearance inspection includes dimensional inspection, shape inspection, and defect inspection based on the height data. Workpiece W is not particularly limited and can include various parts, components, devices, appliances, and portions thereof. Workpiece W can also be referred to as the object of measurement. After workpiece W is moved to the measurable area of ​​the optical displacement meter 1 by a conveying device (not shown), the optical displacement meter 1 performs the displacement measurement.

[0044] The optical displacement gauge 1 is used, for example, fixed to the mounting member 5. The mounting member 5 is part of equipment installed in a factory, etc., and is fixed in a state where it will not move relative to the workpiece W. Therefore, the optical displacement gauge 1 also does not move relative to the workpiece W. Although details are described later, even when the optical displacement gauge 1 is fixed to the mounting member 5, the internal light-emitting and light-receiving module 10 (e.g., Figure 4 The light-receiving module 10 (as shown) can rotate about an axis parallel to the X direction, thereby enabling the slit light S1 extending along the X direction of the workpiece W to scan from the light-receiving module 10 in a direction orthogonal to the X direction of the workpiece W. The reflected light S2, obtained by reflection from multiple locations on the surface W1 of the workpiece W in the Y direction, is received by the light-receiving module 10. Thus, even when the light-receiving module 10 is rotated about an axis parallel to the X direction, the slit light S1 can scan the surface W1 of the workpiece W as if the workpiece W or the optical displacement meter 1 were moving linearly. Furthermore, since the optical displacement meter 1 scans the slit light S1 by rotating the light-receiving module 10, the scanning direction of the slit light S1 includes the Y direction and is orthogonal to the X direction in the YZ plane. In this specification, "rotation" refers to a reciprocating oscillating motion centered on a rotation axis.

[0045] 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. Based on the obtained cross-sectional profiles, data (height data) of the three-dimensional shape of the workpiece W can be generated. Furthermore, since the slit light S1 rotates, the cross-sectional profiles are not necessarily parallel to the XZ plane.

[0046] By allowing the light-emitting and light-receiving module 10, which is located inside the optical displacement gauge 1, to rotate as described above, multiple cross-sectional profiles of the workpiece W at different rotation angles can be obtained without transporting the workpiece W along the Y direction or moving the optical displacement gauge 1 relative to the workpiece W along the Y direction. Therefore, there is no need for equipment such as a conveyor for transporting the workpiece W or a linear motion mechanism for moving the optical displacement gauge 1 relative to the workpiece W along the Y direction, making it easy to incorporate into inspection processes using the optical displacement gauge 1.

[0047] Furthermore, the workpiece W can be allowed to move relative to the optical displacement meter 1, but multiple cross-sectional profiles can be obtained while the workpiece W is stationary during measurement. Alternatively, the optical displacement meter 1 can be allowed to move relative to the workpiece W, but multiple cross-sectional profiles can be obtained while the optical displacement meter 1 is stationary during measurement. This invention is not limited to the case where the optical displacement meter 1 is completely fixed; it can also be supported in a movable manner on the mounting member 5, or mounted on a robotic arm or the like, allowing it to be moved to any measurement location.

[0048] Figure 2 This is a perspective view obtained from above, showing the optical displacement meter 1 according to Embodiment 1 of the present invention. Furthermore, Figure 3 This is a perspective view obtained from below, showing the optical displacement meter 1 according to Embodiment 1 of the present invention. The left-right direction, depth direction, and up-down direction of the optical displacement meter 1 are defined as shown in the figures, but this is for ease of explanation and does not limit the posture in which the optical displacement meter 1 is used. Figure 1 In the illustrated application, the optical displacement meter 1 is positioned above the workpiece W, so the slit light S1 shines downwards and the reflected light S2 travels upwards. In this application, 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. Alternatively, the optical displacement meter 1 can be configured to emit slit light S1 horizontally onto the workpiece W, or it can be configured to emit slit light S1 downwards onto the workpiece W. The orientation of the optical displacement meter 1 is not particularly limited.

[0049] Figure 4 This is a diagram showing the internal structure of the optical displacement meter 1. The optical displacement meter 1 includes a light-emitting and light-receiving module 10 (in... Figure 5 Also shown in the diagram is a motor 20 used to rotate the light-emitting and light-receiving module 10. Figure 7 (shown in the image), motor control unit 30 (in Figure 8 (As shown in the diagram), and housing 40. The light-emitting and receiving module 10, motor 20, and motor control unit 30 are housed in housing 40. Figure 6 As shown, in this 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). Furthermore, in Figure 6 For ease 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 can also be combined.

[0050] The light-projecting and light-receiving module 10 includes: a light-projecting section 11 that irradiates slit light S1 extending in the X direction; a light-concentrating section 12 that has a light-receiving lens that converges the reflected light S2 obtained by the workpiece W; an imaging section 13 that receives the light converged by the light-concentrating section 12; and a support member 14 that holds the light-projecting section 11, the light-concentrating section 12, and the imaging section 13 together.

[0051] like Figure 6 As shown, the light-emitting unit 11 includes a laser emitter (light source) 11a, an optical system 11b, a light source housing that houses the laser emitter 11a and the optical system 11b, and a light-emitting control unit 11c that controls the laser emitter 11a. The laser emitter 11a is controlled by the light-emitting control unit 11c to emit a predetermined amount of laser light at a predetermined time for a predetermined period of time. The light emitted from the laser emitter 11a is incident on the optical system 11b. Although not shown, the optical system 11b is, for example, composed of multiple lenses including cylindrical lenses, which expands the incident laser light into a strip shape to become a slit light S1 and then irradiates the workpiece W. The light-emitting unit 11 is elongated in the irradiation direction of the slit light S1.

[0052] The light-collecting section 12 is configured as a lens unit including multiple large-aperture light-receiving lenses to increase the amount of light received. The light-collecting section 12 has light-receiving lenses and a lens housing for accommodating the light-receiving lenses. Since it includes multiple such large-aperture lenses, its size is relatively large, and therefore the weight of the light-collecting section 12 is heavier than that of the light-projecting section 11.

[0053] The camera unit 13 includes, for example, an image sensor 13a such as a CMOS (Complementary MOS) sensor, and a camera control unit 13b. The image sensor 13a is controlled by the camera control unit 13b to perform image capture at a predetermined time. The exposure time of the image sensor 13a during image capture can be controlled by the camera control unit 13b.

[0054] like Figure 7 , Figure 8 As shown, the support member 14 is made of a flat, highly rigid component, such as a metal sheet. Figure 7 As shown, the support member 14 is fixed to a rotating shaft 50, which forms part of the optical displacement meter 1, and is supported on the housing 40 in a manner that allows it to rotate freely about a rotation center line A, which is the axis of the rotating shaft 50. The extension direction of the support member 14 is orthogonal to the rotation center line A.

[0055] A light-projecting part 11, a light-focusing part 12, and a camera part 13 are fixed on the upper surface of the support member 14. Specifically, in Figure 5In the top view of the light-projecting and light-receiving module 10 shown, the light-projecting part 11 is fixed to the portion of the support member 14 that is to the left of the rotation center line A, and the light-focusing part 12 and the camera part 13 are fixed to the opposite side. Thus, the light-projecting part 11 and the light-focusing part 12 are arranged at intervals from each other in the radial direction (Y direction, Z direction) of the rotation axis 50.

[0056] The projection section 11 is configured so that the slit light S1 is directed toward the Z direction. The focusing section 12 is positioned on the front side (workpiece W side) of the support member 14 with its optical axis aligned with the direction of incident of the reflected light S2. Therefore, both the projection section 11 and the focusing section 12 are oriented toward the Z direction, but the optical axis of the optical system 11b of the projection section 11 and the optical axis (optical axis of the light-receiving lens) of the focusing section 12 intersect each other at a point in the Z direction away from the light-receiving module 10. The distance between the projection section 11 and the focusing section 12 in the left-right direction, and the relationship between the optical axis of the optical system 11b of the projection section 11 and the optical axis of the focusing section 12, can be varied depending on the setting distance of the optical displacement meter 1 relative to the workpiece W, the measurement accuracy, etc.; therefore, the illustrated example is merely one instance.

[0057] The greater the distance between the focusing section 12 and the rotation axis, the greater the moment of inertia of the focusing section 12 due to rotation. When switching the rotation direction of the light-receiving module 10, the light-receiving module 10 needs to be temporarily stopped. At this time, the greater the moment of inertia, the greater the energy required to decelerate the rotational motion of the light-receiving module 10, thus increasing the distance and time until the rotational motion stops. Therefore, the light-receiving module 10 also includes a light-receiving side reflective member 15 fixed to the support member 14. This not only makes the size of the light-receiving module 10 compact, but also reduces the measurement interval by reducing the moment of inertia caused by rotation. The light-receiving side reflective member 15 is, for example, a plane mirror, which refracts the reflected light S2 emitted from the focusing section 12 toward the light-receiving section 11, thereby shortening the distance between the imaging section 13 or the focusing section 12 on the YZ plane and the rotation axis 50 of the light-receiving module 10. The direction of refraction can be, for example, toward the center position in the Y direction of the housing 40. The YZ plane is a plane that includes both a straight line extending along the Y direction and a straight line extending along the Z direction, and is a plane that is orthogonal to the X direction.

[0058] 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-concentrating part 12. On the YZ plane, it is arranged in the optical path between the imaging part 13 and the light-concentrating part 12, so that the light converged by the light-concentrating part 12 is reflected towards the imaging part 13. Furthermore, the rotation axis 50 of the light-projecting and light-receiving module 10 is arranged on the YZ plane between the light-receiving side reflective member 15 and the light-projecting part 11.

[0059] By simply placing the light-receiving side reflector 15 in the optical path between the camera unit 13 and the light-concentrating unit 12, the light converged by the light-concentrating unit 12 can be reflected, thus reducing the area of ​​the light-receiving side reflector 15. Furthermore, the position of the light-receiving side reflector 15 may not be in the optical path between the camera unit 13 and the light-concentrating unit 12, but may be as described in Modification 1 (in...) Figure 17 As shown in the figure, a focusing part 12 is arranged in the optical path between the light-receiving side reflective member 15 and the imaging part 13.

[0060] The light-receiving side reflective member 15 protrudes upward from the upper surface of the support member 14. Furthermore, 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, such that the emission direction of the reflected light S2 is towards the light-receiving surface of the image sensor 13a.

[0061] The positional relationship between the image sensor 13a of the imaging unit 13 and the optical axis of the focusing unit 12 is set to a Scheimpflug relationship, where 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 this embodiment, the projection unit 11, the focusing unit 12, and the imaging unit 13 are integrally held on the support member 14 in a Scheimpflug relationship, thereby constituting the projection and receiving module 10. By focusing along the projection axis of the projection unit 11 in a Scheimpflug relationship, a focused contour image can be obtained from the reflected light obtained by the slit light being reflected by the workpiece W. Therefore, the accuracy of measuring the three-dimensional shape data of the workpiece W is improved, and a high-precision contour can be obtained.

[0062] Even when the light-emitting and light-receiving module 10 is rotated around the rotation center line A, the relative positional relationship of the light-emitting part 11, the light-concentrating part 12, the imaging part 13, and the light-receiving side reflective member 15 remains unchanged. Therefore, the Scheimpflug relationship is maintained regardless of the rotation angle of the light-emitting and light-receiving module 10.

[0063] The camera unit 13 has a protective glass 13c. The protective glass 13c is formed to cover the light-receiving surface of the image sensor 13a and is fixed to the image sensor 13a. The protective glass 13c is made of a light-transmitting member that allows reflected light S2 emitted from the light-receiving side reflective member 15 to pass through. The reflected light S2 that passes through the protective glass 13c forms an image on the light-receiving surface of the image sensor 13a.

[0064] The rotation axis 50 of the light-emitting and light-receiving module 10 is configured to approximately coincide with the center of gravity of the light-emitting and light-receiving module 10 in the YZ plane. That is, the light-emitting and light-receiving module 10, represented by the support member 14, also includes a light-emitting section 11, a light-concentrating section 12, an imaging section 13, and a light-receiving side reflective member 15. When the center of gravity of the light-emitting and light-receiving module 10 is measured or calculated with the light-emitting section 11, the light-concentrating section 12, the imaging section 13, and the light-receiving side reflective member 15 fixed to the support member 14, the center of gravity of the light-emitting and light-receiving module 10 is approximately aligned with the rotation centerline A. In other words, the position of the rotation axis 50 relative to the support member 14 in the Y and Z directions is set such that the center of gravity of the light-emitting and light-receiving module 10 is the center of rotation. The support member 14 is fixed to the rotation axis 50 by multiple connecting members (not shown), and the support member 14 does not rotate relative to the rotation axis 50.

[0065] By aligning the center of gravity of the light-receiving module 10 approximately with the rotation center line A, the moment of inertia of the light-receiving module 10 due to rotation is reduced, while the load on the motor 20 caused by vibration is suppressed, and the decrease in the rotational speed of the light-receiving module 10 is also suppressed. The center of gravity of the light-receiving module 10 does not need to be strictly aligned with the rotation center line A; a deviation within, for example, tolerances is acceptable. Furthermore, even a slight deviation between the center of gravity of the light-receiving module 10 and the rotation center line A can be considered substantially aligned. For example, as long as the moment of inertia of the light-receiving module 10 is sufficiently reduced, the load on the motor 20 caused by vibration is sufficiently suppressed, and the decrease in the rotational speed of the light-receiving module 10 is suppressed, a slight deviation between the center of gravity of the light-receiving module 10 and the rotation center line A is permissible, and they can be considered substantially aligned.

[0066] As described above, the weight increases due to the increased diameter of the focusing section 12. Therefore, it is conceivable that the center of gravity of the light-emitting and receiving module 10, depending on the situation, becomes too close to the focusing section 12, making it difficult to design a system that brings this center of gravity close to the rotation center line A. In this case, if only... Figure 5 As shown by the dotted lines, a counterweight 16 can be provided in the light-emitting module 10 at a position near the light-emitting section 11. This allows the center of gravity of the light-emitting module 10 to be positioned between the light-emitting section 11 and the light-concentrating section 12. The counterweight 16 is positioned on the side opposite to the light-concentrating section 12, separated by the rotation center line A. The counterweight 16 can be fixed to either the support member 14 or the light-emitting section 11. The number of counterweights 16 is not limited to one; multiple counterweights can also be used.

[0067] The closer the rotation axis of the light-emitting and light-receiving module 10 is to its center of gravity, the more stable the rotation and the less load is placed on the rotation axis 50. However, it is conceivable that the weights of the light-emitting part 11 and the light-concentrating part 12 are different. With this structure, a counterweight is provided in the light-emitting and light-receiving module 10 at a position closer to the light-emitting part 11 than to the light-concentrating part 12. This suppresses the deviation of the center of gravity of the light-emitting and light-receiving module 10 from the rotation axis 50 caused by the difference in weight, thus stabilizing the rotation and suppressing the load on the rotation axis 50.

[0068] Alternatively, the counterweight 16 can be omitted, and the material of the light source housing of the light-projecting section 11 can be made of a material with a higher density than the material of the lens housing of the light-concentrating section 12. For example, a relatively low-density material such as aluminum can be used to construct the large-volume support member 14 and the lens housing, while a relatively high-density material such as zinc or stainless steel (SUS) can be used to construct the light source housing. This makes the light-projecting section 11 heavier, thus allowing the center of gravity of the light-projecting and light-receiving module 10 to be positioned between the light-projecting section 11 and the light-concentrating section 12. Furthermore, the material of the housing of the light-projecting section 11 can be made of a material with a higher density than the material of the housing of the light-concentrating section 12, and the counterweight 16 can be provided in the light-projecting and light-receiving module 10 at a position near the light-projecting section 11.

[0069] like Figure 7 As shown, the housing 40 is a component for accommodating the light-emitting and receiving module 10, the motor 20, and the motor control unit 30, and has a two-section 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. Alternatively, the two-section structure can also be referred to as 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.

[0070] The upper shell structure 41 and the lower shell structure 42 can be a single unit or composed of different components. In this embodiment, the case where the upper shell structure 41 and the lower shell structure 42 are composed of different components will be described. In this case, for example, the upper shell structure 41 and the lower shell structure 42 can be joined together by using a joining member (not shown) to form the shell 40.

[0071] like Figure 7 As shown, the upper shell 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 periphery of the upper wall 44 toward the lower shell structure 42. The space formed inside the upper shell structure 41 is called the upper space R1. The upper space R1 is closed by the lower shell structure 42, and the upper space R1 is sealed.

[0072] like Figure 2 andFigure 4 As shown, a projection window 43a and a light-receiving window 43b are provided on the front side of the upper peripheral wall portion 43. The projection window 43a and the light-receiving window 43b are constructed of light-transmitting components. Figure 4 As shown, the projection window 43a is configured to face the surface of the slit light S1 in the projection section 11. The size and position of the projection window 43a are set such that even if the light-receiving module 10 rotates, the slit light S1 can be irradiated from the projection window 43a as long as the rotation angle of the light-receiving module 10 is within the specified angle range described later.

[0073] Furthermore, the light-receiving window 43b is configured to face the light incident surface of the light-concentrating section 12. The size and position of the light-receiving window 43b are set such that even if the light-emitting and light-receiving module 10 rotates, as long as the rotation angle of the light-emitting and light-receiving module 10 is within the specified angle range described later, the reflected light S2 can be incident on the light-concentrating section 12 through the light-receiving window 43b.

[0074] like Figure 7 As shown, the lower housing structure 42 includes a base plate portion 45, a lower peripheral wall portion 46 extending downward from the base plate portion 45, and a cover member 47. The base plate portion 45 extends along the YZ plane and is the portion that closes the lower open portion of the upper housing structure 41. The cover member 47 is installed at the lower end of the lower peripheral wall portion 46. The space formed inside the lower housing structure 42 is called the lower space R2. The lower space R2 is sealed by the cover member 47. In summary, the housing 40 has a structure that seals the interior. A sealed structure refers to a structure that prevents external dust and debris from entering the interior of the housing 40, and can be referred to as a dustproof structure, for example. In addition, the housing 40 may not be completely sealed, for example, there may be gaps that allow air to slightly enter and exit.

[0075] like Figure 3 and Figure 7 As shown in the diagram, recesses 46a are formed on the left and right sides of the lower peripheral wall portion 46 of the lower housing structure portion 42. When viewed along the rotation axis of the light-emitting and light-receiving module 10, the width of the upper space R1 accommodating the light-emitting and light-receiving module is configured to be larger than the width of the lower space R2 accommodating the motor 20, and the recesses 46a are formed on the outer wall of the housing 40 through the step difference between the upper space R1 and the lower space R2. The recesses 46a can be used, for example, as a part for the operator to insert their fingers to hold when installing the optical displacement meter 1. Furthermore, the recesses 46a can be provided as needed. With this structure, a gripping part that helps improve user convenience can be provided without creating an ineffective area within the housing 40.

[0076] like Figure 7As shown, a motor 20 for integrally rotating the light-emitting and light-receiving module 10 is housed in the lower space R2. The central axis of the motor 20 housed in the lower space R2 coincides with the axis of the rotation shaft 50, and this central axis extends in the vertical direction. On the other hand, the light-emitting and light-receiving module 10 is housed in the upper space R1. The upper space R1 and the lower space R2 are side by side in the direction of the rotation axis of the light-emitting and light-receiving module 10 (the central axis of the motor 20), so the light-emitting and light-receiving module 10 housed in the upper space R1 is configured to be side by side with the motor 20 housed in the lower space R2 in the direction of the central axis of the motor 20. In other words, it is a multi-segment optical displacement meter 1 with the light-emitting and light-receiving module 10 arranged in the upper segment and the motor 20 arranged in the lower segment.

[0077] The light-emitting and light-receiving module 10 is configured to be parallel to the motor 20 along the central axis of the motor 20. Therefore, when setting the positional relationship between the light-emitting part 11 and the light-receiving part 12 of the light-emitting and light-receiving module 10, it is less affected by the motor 20. Consequently, it is also possible to design a system that does not have a large gap between the light-emitting part 11 and the light-receiving part 12, for example, when the installation distance is relatively short.

[0078] The optical displacement meter 1 also includes a bearing 51 for supporting the rotation shaft 50 of the light-emitting and light-receiving module 10 in a rotatable manner. As described above, the weight of the light-emitting and light-receiving module 10 increases, therefore, for example, when using… Figure 1 When using the optical displacement meter 1 in the shown posture, a torque load is generated on the rotating shaft 50 due to the weight of the light-emitting and light-receiving module 10. Specifically, due to the difference between the part of the rotating shaft 50 supported by the bearing 51 and the center of gravity of the light-emitting and light-receiving module 10, a torque load acts on the rotating shaft 50 in the direction that tilts the shaft core relative to the horizontal plane. Especially in the case of the two-section structure described above, the upper housing structure 41 and the lower housing structure 42 are arranged side by side in the direction of the central axis of the motor 20 (the rotating shaft of the light-emitting and light-receiving module 10), so the difference between the part of the rotating shaft 50 supported by the bearing 51 and the center of gravity of the light-emitting and light-receiving module 10 tends to be relatively large. In contrast, the bearing 51 of this embodiment is configured to support the torque load generated by the difference between the part of the rotating shaft 50 supported by the bearing 51 and the center of gravity of the light-emitting and light-receiving module 10.

[0079] As the bearing 51 capable of supporting the aforementioned torque load, a crossed roller bearing can be used, for example, in which a plurality of rollers 51c are arranged between an annular outer ring member 51a and an inner ring member 51b, such that the axes of adjacent rollers 51c in the circumferential direction are orthogonal to each other. That is, a stepped portion 45a for inserting the outer ring member 51a is formed annularly on the base plate portion 45 of the lower housing structure portion 42. The outer ring member 51a is fixed to the base plate portion 45 in a state of being inserted into the stepped portion 45a. On the other hand, a fitting portion 50a for fitting the inner ring member 51b is formed on the upper part of the rotating shaft 50. The inner ring member 51b is fixed in a state of being fitted into the fitting portion 50a. In addition, the inner ring member 51b can also be fixed to the support member 14 of the light-emitting and light-receiving module 10.

[0080] By using a crossed roller bearing 51, with rollers 51c in line contact with the outer ring member 51a and the inner ring member 51b, the rigidity is significantly improved compared to ball bearings. Therefore, a thin and compact bearing structure can be designed in the axial direction, and it can withstand not only radial loads (radial loads) on the rotating shaft 50 but also axial loads (axial loads), thus improving rigidity against the aforementioned torque loads. Therefore, smooth rotation can be achieved regardless of the orientation of the optical displacement gauge 1 during operation.

[0081] The bearing 51 can also be built into the motor 20. Alternatively, the bearing 51 can be a bearing other than a crossed roller bearing. When using a bearing other than a crossed roller bearing, for example, two or more ball bearings can be arranged spaced apart from each other in the axial direction of the rotating shaft 50. This creates a bearing configuration capable of supporting the aforementioned torque load. When using two or more ball bearings, one ball bearing can be held in the base plate portion 45 of the lower housing structure portion 42, and the other ball bearing can be built into the motor 20.

[0082] The optical displacement meter 1 also includes an encoder 52 for detecting the rotation angle of the rotating shaft 50, i.e., the rotation angle of the light-emitting and light-receiving module 10. The encoder 52 is an optical encoder. Optical encoders are well known, and although not shown, they typically include, for example, 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. They are configured to allow light irradiated from the light source to pass through slits formed at equal intervals on the rotating plate and the fixed plate and be received by the light-receiving body. The amount of light received is converted into an electrical signal to generate a pulse and output the pulse.

[0083] By making the encoder 52 an optical encoder, the detection accuracy of the rotation angle is improved compared to a magnetic encoder, but its resistance to dust and other contaminants is weakened. Conversely, by housing the encoder 52 inside the housing 40, specifically in a sealed lower space R2 as described above, dust and other contaminants do not adhere to the encoder 52. For example, the sealed space containing the encoder 52 prevents debris and dust from entering the housing 40 even when adjusting the position and orientation of the camera unit 13 in the upper space R1 containing the light-emitting module 10. This prevents debris and dust from entering the lower space R2 containing the encoder 52 from the upper space R1, which houses and rotates the light-emitting module 10. Therefore, by using an optical encoder, which offers high accuracy but is susceptible to debris and dust, high-precision measurements can be performed.

[0084] Motor 20 is a direct drive motor that directly drives the light-emitting and light-receiving module 10. Direct drive means that there is no reduction gear mechanism inserted between motor 20 and the driven object. This will be described later, but the present invention is not limited to direct drive motors.

[0085] The motor 20 includes a stator 21 composed of coils and a rotor 22 composed of permanent magnets. The rotor 22 is fixed in the portion between the bearing 51 and the encoder 52 in the outer periphery of the rotating shaft 50. The stator 21 is fixed to the lower housing structure 42 and is configured to surround the rotor 22.

[0086] 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 rotational speed of the motor 20 to a desired speed and the rotational 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 rotational angle of the light-emitting and light-receiving module 10 based on the pulse signal output from the encoder 52.

[0087] When the scanning start position, scanning end position, and scanning range of the slit beam S1 for the workpiece W are set by checking the settings, the starting position, rotation end position, and rotation angle of the light-emitting and receiving module 10 corresponding to the set scanning start position, scanning end position, and scanning range can be calculated. Based on the calculation results, the motor control unit 30 controls the motor 20 to rotate the light-emitting and receiving module 10, which maintains a Scheimpflug relationship inside the housing 40, so that the slit beam S1 scans in a direction orthogonal to the X direction.

[0088] The light-emitting and receiving module 10 is housed in the upper space R1 of the housing 40. Therefore, depending on the rotation angle of the light-emitting and receiving module 10, there is a concern that a portion of the light-emitting and receiving module 10 may come into contact with the inner wall of the housing 40. In contrast, in this embodiment, the rotation angle range of the light-emitting and receiving module 10 during the use of the optical displacement meter 1, i.e., during measurement, is set to a predetermined angle range that prevents the light-emitting and receiving module 10 from contacting the inner wall of the housing 40. That is, although the light-emitting and receiving module 10 has a dimension that contacts the inner wall of the housing 40 on the YZ plane orthogonal to the X direction when it is assumed to rotate to a first rotation angle, the rotation angle range of the light-emitting and receiving module 10 during measurement is set to a predetermined angle range smaller than the aforementioned first rotation angle to prevent the light-emitting and 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 receiving module 10, thus the housing 40 is easily miniaturized.

[0089] As a method for setting the rotation angle range of the light-emitting and light-receiving module 10 to a predetermined angle range, there are, for example, mechanically implemented methods and software-implemented methods. In this embodiment, as a mechanically implemented method, a mechanism is provided inside the housing 40 such as... Figure 4 The first stop 61 and the second stop 62 are examples of mechanical components shown. In this example, the first stop 61 and the second stop 62 are configured to protrude upwards from the base plate portion 45. When the light-emitting and light-receiving module 10 rotates about the rotation center line A in the direction of arrow B, the light-emitting and light-receiving module 10 abuts against the first stop 61 before a portion of the light-emitting and light-receiving module 10 contacts the inner wall of the housing 40, thereby preventing the light-emitting and light-receiving module 10 from rotating further in the direction of arrow B. Similarly, when the light-emitting and light-receiving module 10 rotates about the rotation center line A in the direction of arrow C, the light-emitting and light-receiving module 10 abuts against the second stop 62 before a portion of the light-emitting and light-receiving module 10 contacts the inner wall of the housing 40, thereby preventing the light-emitting and light-receiving module 10 from rotating further in the direction of arrow C. In other words, the first stop 61 and the second stop 62 are provided inside the housing 40 to prevent the light-emitting and light-receiving module 10 from rotating outside a predetermined angle range during measurement.

[0090] The first stop 61 and the second stop 62 can also be made of elastic components such as rubber or thermoplastic elastomers. Alternatively, the first stop 61 and the second stop 62 can be made of metal, and elastic components can be provided at the portions in the support member 14 where the first stop 61 and the second stop 62 abut. This reduces the noise generated when the light-emitting and light-receiving module 10 abuts against the first stop 61 and the second stop 62.

[0091] Furthermore, it is preferable that the support member 14 abuts against the first stop member 61 and the second stop member 62. This is because if the light-projecting part 11, the light-focusing part 12, etc., abut against the first stop member 61 and the second stop member 62, there is a concern that the optical axis may deviate due to the impact during the abutment. Alternatively, the first stop member 61 and the second stop member 62 may also be provided on the upper peripheral wall part 43. Moreover, it is also possible to provide only one of the first stop member 61 and the second stop member 62.

[0092] Next, a software-based method will be explained. That is, by executing contact avoidance control by the motor control unit 30, contact between the light-emitting 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-emitting and light-receiving module 10 rotates within a predetermined angle range during measurement. This control is contact avoidance control. By executing this contact avoidance control, contact between the light-emitting and light-receiving module 10 and the inner wall of the housing 40 can be avoided without providing the stops 61 and 62. Alternatively, stops 61 and 62 can also be provided even when contact avoidance control is executed.

[0093] The goal is simply to prevent the light-emitting and light-receiving module 10 from contacting the inner wall of the housing 40 during measurement. Alternatively, the light-emitting and light-receiving module 10 can contact the inner wall of the housing 40 during non-measurement periods, such as maintenance or various setting times. Therefore, the motor control unit 30 can be configured to perform contact avoidance control only during measurement.

[0094] like Figure 8 As shown, a substrate receiving space R3 is provided in the lower housing structure portion 42. Figure 4 In the top view shown, the substrate receiving space R3 is offset to the rearward side relative to the center of the housing 40, and is therefore positioned with respect to the motor 20 (in Figure 7 (As shown in the diagram) The position is located further back than the upper space R1. Furthermore, the substrate accommodating space R3 is located below the upper space R1 that houses the light-emitting and light-receiving module 10, and is therefore a different space from the upper space R1. In the direction of the rotation axis of the light-emitting and light-receiving module 10, the substrate accommodating space R3 is positioned differently from the upper space R1, but is positioned at the same location as the lower space R2 that houses the motor 20. When viewed along the rotation axis of the light-emitting and light-receiving module 10, the upper space R1 and the lower space R2 are positioned overlapping the rotation axis, while the substrate accommodating space R3 is positioned not overlapping the rotation axis. For example, when the size of the light-emitting and light-receiving module 10 is larger than the size of the motor 20, by using a two-section structure with the upper space R1 housing the light-emitting and light-receiving module 10 as the first section and the lower space R2 housing the motor 20 and the substrate accommodating space R3 housing the motor control unit 30 as the second section, the shape of the housing 40 can be made more compact.

[0095] like Figure 8 As shown, the substrate accommodating space R3 houses a motor control substrate 31 on which the motor control unit 30 is mounted, a signal processing substrate 33 on which the signal processing unit 32 is mounted, and a power supply substrate 35 on which the power supply unit 34 is mounted. The motor control substrate 31 and the signal processing substrate 33 are equipped with processors such as CPUs (Central Processing Units), DSPs (Digital Signal Processors), and FPGAs (Field Programmable Gate Arrays) that function as the motor control unit 30 and the signal processing unit 32, and with storage elements such as RAMs (Random Access Memory) and ROMs (Read-Only Memory) (not shown) for storing programs executed by these processors. Each substrate 31, 33, and 35 is fixed to the lower housing structure 42. By accommodating the motor control unit 30 and the signal processing unit 32 in a substrate accommodating space R3, which is different from the upper space R1, the light-emitting unit 11, which is particularly prone to heat generation, can be thermally separated from the motor control unit 30 and the signal processing unit 32, thus stabilizing the operation of the motor control unit 30 and the signal processing unit 32. Furthermore, the configuration of the control unit 3 is not limited to the examples described above. For example, it may also be a structure in which the signal processing unit 32 is housed inside the housing 40 and the motor control unit 30 is disposed outside the housing 40.

[0096] The reflected light S2 enters from the front side of the housing 40. Therefore, the motor control unit 30, signal processing unit 32, and power supply unit 34, housed on the rear side of the housing 40, are positioned opposite to the side where the reflected light S2 enters, relative to the light-emitting and light-receiving module 10. This ensures that the motor control unit 30, signal processing unit 32, and power supply unit 34 do not obstruct displacement measurement. Furthermore, when the Z-direction is used as a reference, the motor control unit 30, signal processing unit 32, and power supply unit 34 are arranged adjacent to the light-emitting and light-receiving module 10 in the Z-direction. Additionally, the substrate accommodating space R3 is sealed by the cover member 47, thus preventing dust and other contaminants from adhering to each of the substrates 31, 33, and 35.

[0097] 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-emitting and light-receiving module 10, but it is positioned below the support member 14 of the light-emitting and light-receiving module 10. Therefore, the light-emitting and light-receiving module 10 will not come into contact with the signal processing board 33 when it rotates within a predetermined angle range. 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-emitting and light-receiving module 10, which rotates during measurement.

[0098] The power supply unit 34 supplies power to the light-emitting unit 11, the camera unit 13, the motor control unit 30, and the signal processing unit 32. In this embodiment, the power supply unit 34, the motor control unit 30, and the signal processing unit 32 are mounted on different substrates, but this is not a limitation; any two or more of them may be mounted together on one substrate.

[0099] The signal processing unit 32, for example, is composed of a microcomputer, ROM, RAM, etc., and operates according to a predetermined program. It is the part that generates the cross-sectional contour data of the workpiece W based on the amount of light received by the camera unit 13. Figure 4 The wiring, indicated by reference numeral 70, connects the substrates 31, 33, and 35 to the light-projecting unit 11 and the camera unit 13. This wiring 70 is flexible and configured not to affect the rotation of the light-projecting and light-receiving module 10.

[0100] like Figure 9 As shown, the image sensor 13a of the imaging unit 13 has a plurality of pixels arranged in two dimensions in the U direction corresponding to the X direction and in the V direction orthogonal to the U direction. The signal processing unit 32 acquires the brightness value (light received amount) of each pixel of the image sensor 13a and calculates an approximate curve of brightness value change. The signal processing unit 32 calculates the peak position in the V direction of each pixel column in the calculated approximate curve and uses the calculated peak position as the displacement of the workpiece W.

[0101] The signal processing unit 32 performs the peak position calculation described above 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 at which the peak position is obtained, and stores this as measurement data. Since the rotation angle and UV coordinates of the light-emitting and light-receiving module 10 correspond to the XYZ coordinates of the workpiece, it is possible to generate cross-sectional profile data of the workpiece W at the desired rotation angle based on the measurement data. Furthermore, by obtaining multiple cross-sectional profiles of the workpiece W at different rotation angles, the signal processing unit 32 can generate three-dimensional shape data of the workpiece W.

[0102] (Readout area of ​​the image sensor)

[0103] As described above, in this embodiment 1, by rotating the light-emitting and light-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 signal read from the image sensor 13a at different rotation angles of the light-emitting and light-receiving module 10.

[0104] Figure 10An example is shown of measuring the displacement of a workpiece W whose surface W1 is at the same height (surface W1 is parallel to the Y direction). If we assume that the optical displacement meter 1 is moved linearly in a direction parallel to the surface W1 of the workpiece W (shown 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 defined as a local area, thereby speeding up the processing.

[0105] On the other hand, when the slit light S1 is scanned in a direction orthogonal to the X direction by rotating the light-emitting and light-receiving module 10 as in Embodiment 1, sometimes, as will be explained below, it is not possible to measure the surface W1 of the workpiece W in the Y direction. That is, in Figure 10 In this context, the largest area that can be read by the image sensor 13a is set as the largest area (measurable range) F1, which is approximately an arc shape centered on the rotation axis of the camera unit and has a predetermined depth. If the area that is the object of reading the pixel signal of the image sensor 13a when measuring displacement is always set as the largest area F1, the processing load of the signal processing unit 32 will increase, making it difficult to achieve high-speed measurement. Therefore, it is conceivable to set the area that is the object of reading the pixel signal of the image sensor 13a as the area below the line L1, i.e., the local area F2.

[0106] However, when the light-emitting and light-receiving module 10 is rotated, the local region F2 is an arc-shaped and long region centered on the rotation center line A of the light-emitting and light-receiving module 10. Therefore, even if the surface W1 is at the same height, the part to the right of the straight line L2 is located outside the local region F2, so it is impossible to use the local region F2 for measurement.

[0107] In response to this situation, such as Figure 11 As shown, the camera control unit 13b of this embodiment 1 is configured to dynamically change the local region F3 (shown in slashes) that is the object of reading pixel signals from the image sensor 13a in accordance with the rotation angle of the light-emitting and light-receiving module 10. The camera control unit 13b is configured to obtain the rotation angle of the motor 20 based on the signal from the encoder 52, and therefore can change the position of the local region F3 in the image sensor 13a in the V direction of the image sensor 13a according to the rotation angle of the motor 20.

[0108] based on Figure 11To illustrate, let's look at an example of how the camera control unit 13b changes the position of the local region F3. When the rotation angle of the light-emitting module 10 is θ1, the camera control unit 13b sets the position of the local region F3 in the image sensor 13a such that the local region F3 is located below the image sensor 13a. When the rotation angle of the light-emitting module 10 is θ2, the camera control unit 13b sets the position of the local region F3 in the image sensor 13a such that the local region F3 is located in the middle of the vertical direction of the image sensor 13a. When the rotation angle of the light-emitting module 10 is θ3, the signal processing unit 32 sets the position of the local region F3 in the image sensor 13a such that the local region F3 is located above the image sensor 13a. In other words, when the rotation angle of the light-emitting 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, and conversely, when the rotation angle of the light-emitting 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. Furthermore, the rotation angle of the motor 20 corresponds to the rotation angle of the light-emitting and light-receiving module 10, so either the rotation angle of the motor 20 or the rotation angle of the light-emitting and light-receiving module 10 can be used each time this control is performed. Here, we assume that the motor 20 is a direct-drive motor as described later, so the rotation angle of the motor 20 is equal to the rotation angle of the light-emitting and light-receiving module 10. However, when using the motor 20 and the reduction mechanism 25, the rotation angle of the motor 20 and the rotation angle of the light-emitting and light-receiving module 10 may sometimes differ depending on the rotation ratio.

[0109] The camera control unit 13b sets the width H1 in the V direction of the local region F3 when the light-receiving module 10 rotates at an angle θ1, the width H2 in the V direction of the local region F3 when the light-receiving module 10 rotates at an angle θ2, and the width H3 in the V direction of the local region F3 when the light-receiving module 10 rotates at an angle θ3 to be the same. In short, the camera control unit 13b makes the number of read pixels in the V direction of the local region F3 the same at different rotation angles of the light-receiving module 10, so that the area of ​​read light amount in the approximately arc-shaped measurable range F1 contains a common height in the Z direction, and changes the local region F3 according to each rotation angle. If the surface of the workpiece W is flat, the camera control unit 13b can also change the local region F3 according to each rotation angle so that the area of ​​read light amount in the approximately arc-shaped measurable range F1 is approximately consistent in the Z direction from one end of the approximately arc-shaped measurable range F1 to the other end. Therefore, regardless of the rotation angle of the light-emitting and light-receiving module 10, the camera control unit 13b can move the local region F3 that reads pixel signals from the image sensor 13a along the V direction in a manner that at least a portion of the measurement range in the Z direction is common. Furthermore, the width H1 of the local region F3 in the V direction when the rotation angle of the light-emitting and light-receiving module 10 is θ1 can be different from the width H2 of the local region F3 in the V direction when the rotation angle of the light-emitting and light-receiving module 10 is θ2. Similarly, the width H1 of the local region F3 in the V direction when the rotation angle of the light-emitting and light-receiving module 10 is θ1 can be different from the width H3 of the local region F3 in the V direction when the rotation angle of the light-emitting and light-receiving module 10 is θ3.

[0110] The camera control unit 13b is configured to set a local region F3, which is the object for reading pixel signals from the image sensor 13a, based on the rotation angle of the light-emitting and light-receiving module 10 and the height of the workpiece W corresponding to the rotation angle of the light-emitting and light-receiving module 10. For example, Figure 12 The diagram illustrates how the height of surface W1 of workpiece W varies depending on its location. Compared to when the rotation angle of the light-emitting and light-receiving module 10 is θ1, the height of surface W1 is lower when the rotation angle of the light-emitting and light-receiving module 10 is θ2. Conversely, compared to when the rotation angle of the light-emitting and light-receiving module 10 is θ2, the height of surface W1 is higher when the rotation angle of the light-emitting and light-receiving module 10 is θ3.

[0111] In such Figure 12In the case of the workpiece W shown, when the rotation angle of the light-emitting 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 such that the local area F3 is the lower area of ​​the image sensor 13a. When the rotation angle of the light-emitting and light-receiving module 10 is θ2, the camera control unit 13b also sets the position of the local area F3 in the image sensor 13a such that the local area F3 is the lower area of ​​the image sensor 13a. On the other hand, when the rotation angle of the light-emitting 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 such that the local area F3 is the upper area of ​​the image sensor 13a.

[0112] When the camera control unit 13b sets the position of the local region F3 based on the rotation angle of the light-receiving module 10 and the height of the workpiece W corresponding to that rotation angle, it can determine the correspondence between each rotation angle of the light-receiving module 10 and the height of the workpiece W corresponding to that rotation angle based on information obtained before operation by measuring the workpiece W using an area wider than the local region F3 using the image sensor 13a. After operation begins, based on this correspondence, the local region F3 is determined in a manner that includes the position of the workpiece W in the V direction of the image sensor 13a corresponding to the height of the workpiece W. That is, when setting the optical displacement meter 1, the displacement of the workpiece W is measured using an area wider than the local region F3 using the image sensor 13a. At this time, the displacement of the workpiece W can also be measured using the maximum area F1 of the image sensor 13a. Thus, if such Figure 12 The workpiece W shown can have its displacement measured in the Y direction. This measurement information is temporarily stored.

[0113] After measuring the displacement of the workpiece W using a region larger than the local region F3 of the image sensor 13a, the camera control unit 13b, based on the measurement information, sets the position of the local region F3 in the image sensor 13a such that the local region F3 is the lower region of the image sensor 13a when the rotation angle of the light-emitting and light-receiving module 10 is θ1 and θ2, and sets the position of the local region F3 in the image sensor 13a such that the local region F3 is the upper region of the image sensor 13a when the rotation angle of the light-emitting and light-receiving module 10 is θ3. In other words, the camera control unit 13b sets the position of the local region F3 in the image sensor 13a in the following way: by setting a region of the image sensor 13a smaller than the maximum region F1 as the local region F3, high-speed processing is achieved, and the surface W1 of the workpiece W can be measured regardless of the rotation angle of the light-emitting and light-receiving module 10. Furthermore, during application, the position of the local area F3 in the image sensor 13a changes dynamically in accordance with the rotation angle of the light-emitting and light-receiving module 10, thus enabling the displacement to be measured in the Y direction of the workpiece W.

[0114] When determining the correspondence between the rotation angle of the light-emitting and light-receiving module 10 and the height of the workpiece W, the camera control unit 13b can also make the decision based on the actual size data or design data of the workpiece W. For example, in... Figure 12 In the case of the workpiece W shown, the operator can use a measuring device (not shown) to measure the height of the workpiece W by part, thereby obtaining the actual size data of the workpiece W. The obtained actual size data of the workpiece W is input to the camera control unit 13b. In this case, based on the actual size data of the workpiece W, for example, when the rotation angle of the light-emitting and light-receiving module 10 is θ1 and θ2, the camera control unit 13b determines that the local area F3 is the lower area of ​​the image sensor 13a, and when the rotation angle of the light-emitting and light-receiving module 10 is θ3, the local area F3 is determined to be the upper area of ​​the image sensor 13a.

[0115] Additionally, design data (such as CAD data) for the workpiece W can be input to the camera control unit 13b. The height of the surface W1 of the workpiece W can be obtained by location based on the design data. Therefore, similar to the case where the actual dimensions of the workpiece W are input, the position of the local region F3 within the image sensor 13a can be determined.

[0116] (Modification 1 of Implementation Method 1)

[0117] Figure 13The light-emitting and light-receiving module 10 according to a variation of embodiment 1 is shown. The positions of the light-emitting part 11, the light-concentrating part 12, the imaging part 13, and the light-receiving side reflective member 15 in the light-emitting and light-receiving module 10 of variation 1 differ from those in the above embodiment. Specifically, the rotation axis 50 of the light-emitting and light-receiving module 10 is arranged in the YZ plane at a position overlapping with the light-concentrating part 12. That is, as described above, although it is desirable to minimize the moment of inertia generated by the rotation of the light-emitting and light-receiving module 10, when such a configuration is provided… Figure 5 The weight of the light-emitting and receiving module 10 increases when the counterweight 16 is shown as a virtual line, which is sometimes undesirable. Therefore, the counterweight 16 is not provided. Instead, as a method to reduce the moment of inertia caused by the rotation of the light-emitting and receiving module 10, the light-concentrating part 12, which increases in weight, overlaps with the rotation axis 50 of the light-emitting and receiving module 10 in the YZ plane. Thus, at least a portion of the light-concentrating part 12 is arranged on the extension line of the rotation axis 50 of the light-emitting and receiving module 10. Furthermore, the rotation axis 50 does not need to completely overlap with the light-concentrating part 12, as long as at least a portion of the rotation axis 50 overlaps with at least a portion of the light-concentrating part 12 when viewed from the rotation center line A. Thus, the counterweight 16 is unnecessary, or the counterweight 16 can be made lighter.

[0118] In addition, in Modification 1, the camera unit 13 and the light-receiving side reflector 15 are arranged to sandwich the light-concentrating unit 12 in the middle. Thus, in Modification 1, the light-concentrating unit 12 is arranged on the YZ plane in the optical path between the light-receiving side reflector 15 and the camera unit 13, so that the light reflected by the light-receiving side reflector 15 is converged and incident on the camera unit 13.

[0119] Furthermore, the light-emitting and light-receiving module 10 of Modified Example 1 includes a light-emitting side reflector 17. That is, the light-emitting section 11 of Modified Example 1 is configured such that the slit light S1 emitted from the optical system 11b is directed to the far rear left side. This allows the light-emitting section 11 to be closer to the rotation center line A, further reducing the moment of inertia caused by the rotation of the light-emitting and light-receiving module 10. However, the workpiece W is located on the side opposite to the slit light S1 emitted from the optical system 11b. The light-emitting side reflector 17 is configured to reflect the slit light S1 emitted from the optical system 11b of the light-emitting section 11 toward the workpiece W to address this situation. This light-emitting side reflector 17 is fixed to the support member 14 or the light-emitting section 11, so that the relative positional relationship between the light-emitting side reflector 17 and the light-emitting section 11 does not change even if the light-emitting and light-receiving module 10 rotates.

[0120] (Modification 2 of Implementation Method 1)

[0121] Figure 14 and Figure 15 An optical displacement meter 1 according to a variation 2 of embodiment 1 is shown. Figure 14This diagram shows the internal structure of the optical displacement meter 1 as viewed from above. Figure 15 This is a diagram obtained by observing the internal structure of the optical displacement meter 1 from below.

[0122] In the optical displacement meter 1 of variant example 2, the motor 20 is not a direct drive motor, but rather a structure in which the light-emitting and light-receiving module 10 is rotated via a reduction mechanism 25. For example... Figure 14 As shown, the motor 20 and the light-emitting and light-receiving module 10 are housed together in the upper space R1. Figure 15 As shown, the output shaft 20a of the motor 20 passes downward through the substrate 45 to reach the lower space R2. In addition, the driven shaft 10a, which is fixed to the light-emitting and light-receiving module 10, also passes downward through the substrate 45 to reach the lower space R2.

[0123] The reduction mechanism 25 is housed in the lower space R2 and includes a drive 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 drive pulley 25a and the driven pulley 25b. The drive pulley 25a is configured to have a smaller diameter than the driven pulley 25b. The transmission belt 25c is a synchronous belt.

[0124] In Modification 2, when the output shaft 20a of the motor 20 housed in the upper space R1 rotates, the drive pulley 25a rotates, and the rotational force of the drive pulley 25a is transmitted to the driven pulley 25b via the transmission belt 25c. The driving force transmitted to the driven pulley 25b is then transmitted to the driven shaft 10a, thus enabling the light-emitting and light-receiving module 10 to rotate via the motor 20. In Modification 2, the driven shaft 10a is the rotation axis of the light-emitting and light-receiving module 10.

[0125] Furthermore, the reduction mechanism 25 is not limited to a combination of pulleys 25a and 25b and a drive belt 25c; for example, it can also be composed of a combination of a drive sprocket, a driven sprocket, and a synchronization chain, or a combination of multiple gears. Regarding the type of motor 20, for example, a DC motor, a stepper motor, or a servo motor can be used.

[0126] (Implementation Method 2)

[0127] Figure 16~Figure 18 This diagram illustrates the optical displacement meter 1 according to Embodiment 2 of the present invention. In this 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., differ from those in Embodiment 1. Hereinafter, the same reference numerals will be used for the parts that are the same as in Embodiment 1, and the descriptions will be omitted. The different parts will be described in detail.

[0128] like Figure 16 and Figure 18As shown, the housing 400 is a structure in which substrates 31, 33, and 35 are also housed. The interior of the housing 400 can also be divided so that the space housing substrates 31, 33, and 35 is a different space from the space housing the light-emitting and light-receiving module 100.

[0129] The housing 400 includes a lower wall portion 401, a peripheral wall portion 402 extending upward from the periphery of the lower wall portion 401, and an upper cover member 403 for closing the upper open portion. A projection window 402a for transmitting slit light S1 irradiated by the projection portion 11 and a light-receiving window 402b for transmitting reflected light S2 reflected from the workpiece W are provided on the front side of the peripheral wall portion 402.

[0130] like Figure 18 As shown, an annular wall portion 404 protruding into the interior of the housing 400 and extending around the rotation center line A is formed at the center of the lower wall portion 401. An end wall portion 405 extending radially along the rotation center line A is formed at the front end of the annular wall portion 404. An opening portion 405a for inserting the rotation shaft 50 is formed at the center of the end wall portion 405.

[0131] A motor housing space R4 is formed inside the annular wall portion 404. The stator 21 and rotor 22 of the motor 20 are housed in the motor housing space R4. The stator 21 of the motor 20 is fixed to the inner surface of the annular wall portion 404. That is, in this embodiment, the annular wall portion 404 and the end wall portion 405 constitute the stator holding portion. On the other hand, the rotor 22 of the motor 20 is fixed to the rotation shaft 50.

[0132] The outer ring member 51a of the bearing 51 is fixed to the end wall portion 405 in a state where it is embedded in the stepped portion 405b formed in the end wall portion 405. Thus, the bearing 51 is held in the stator holding portion formed 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 in the rotating shaft 50.

[0133] The encoder 52 is also housed in the motor housing space R4. A lower side cover member 406 is provided at the lower end of the housing 400. The lower side cover member 406 seals the motor housing space R4, so that dust and the like will not adhere to the encoder 52.

[0134] Similar to Embodiment 1, the light-emitting and light-receiving module 100 includes a light-emitting part 11, a light-concentrating part 12, a camera part 13, a counterweight 16, etc., but the support member 110 that holds the light-emitting part 11, the light-concentrating part 12 and the camera part 13 together is very different from the support member 14 of Embodiment 1.

[0135] That is, in Embodiment 1, the light-emitting and light-receiving module 10 and the motor 20 (bearing 51 and encoder 52) are arranged side by side in the direction of the rotation axis 50 (height direction). In contrast, in Embodiment 2, a portion of the height range in the direction of the rotation axis 50 of the light-emitting and light-receiving module 100 includes at least one of the motor 20, the bearing 51 supporting the rotation axis 50, and the encoder 52 connected to the motor 20. Therefore, when setting the positional relationship between the light-emitting part 11 and the light-receiving part 12 of the light-emitting and light-receiving module 100, it is possible to design a large interval between the light-emitting part 11 and the light-receiving part 12, taking into account, for example, the case where the installation distance is relatively long.

[0136] In a specific description, the support member 110 includes a fixing part 111 fixed to the rotation shaft 50, a one-side longitudinal plate part 112 and a other-side longitudinal plate part 113, a light-concentrating part holding part 114, and a light-projecting part holding part 115. The fixing part 111, the one-side longitudinal plate part 112, the other-side longitudinal plate part 113, the light-concentrating part holding part 114, and the light-projecting part holding part 115 can be integrally formed or can be constructed by combining different components.

[0137] The fixing part 111 is a plate extending radially along the rotation axis 50. In this embodiment, for example... Figure 17 As shown, it is a circular shape, such as Figure 18 As shown, it is configured to cover the end wall portion 405 from above. The longitudinal plate portion 112 on one side... Figure 18 The right side, that is, the radial side of the rotating shaft 50 in the fixing part 111, extends downward along the direction of the rotating shaft 50. The other side of the longitudinal plate part 113 extends from... Figure 18 The left side, that is, the other side of the rotation axis 50 in the fixing part 111, extends downward along the direction of the rotation axis 50. One side longitudinal plate part 112 and the other side longitudinal plate part 113 are arranged to face the annular wall part 404. In addition, the one side longitudinal plate part 112 and the other side longitudinal plate part 113 are curved into an arc shape like the annular wall part 404. When the light-emitting and light-receiving module 100 rotates, the one side longitudinal plate part 112 and the other side longitudinal plate part 113 rotate with a certain gap between them and the annular wall part 404.

[0138] Furthermore, the longitudinal plate portion 112 on one side and the longitudinal plate portion 113 on the other side can also be integrally formed. For example, an annular peripheral wall portion (not shown) extending downward from the periphery of the fixing portion 111 can also be formed, and the longitudinal plate portion 112 on one side and the longitudinal plate portion 113 on the other side can be formed by a portion of the circumferential direction of the peripheral wall portion.

[0139] The light-collecting section holding section 114 is plate-shaped, extending radially along the rotation axis 50 from the lower end of the longitudinal plate section 112 on one side. The light-collecting section 12, the imaging section 13, the protective glass 13c, etc. are held on the upper surface of the light-collecting section holding section 114. Therefore, the rotation axis 50 of the light-projecting and light-receiving module 100 is arranged in the YZ plane at a position that does not overlap with the light-collecting section 12 and the imaging section 13.

[0140] The light-emitting part holding part 115 is plate-shaped, extending radially along the rotation axis 50 from the lower end of the other side longitudinal plate part 113. The light-emitting part 11, counterweight 16, etc. are held on the upper surface of the light-emitting part holding part 115. Therefore, the rotation axis 50 of the light-emitting and light-receiving module 100 is arranged in the YZ plane at a position that does not overlap with the light-emitting part 11.

[0141] Thus, the focusing part holding part 114 and the projection part holding part 115 are configured to sandwich the rotation shaft 50 in the middle, and protrude in opposite directions in the radial direction of the rotation shaft 50. The counterweight 16 can be fixed to the projection part holding part 115. Alternatively, the counterweight 16 can be fixed to the side of the fixing part 111 opposite to the side where the longitudinal plate part 112 is formed.

[0142] The support member 110, which has a fixing part 111, a longitudinal plate part 112 on one side, a longitudinal plate part 113 on the other side, a light-concentrating part holding part 114, and a light-projecting part holding part 115, has a plurality of curved parts 110A in the X-direction section. Because the support member 110 has a plurality of curved parts 110A in this way, its rigidity can be improved compared to the case where the support member 110 is a flat plate.

[0143] The motor 20 and bearing 51 are disposed between one side longitudinal plate portion 112 and the other side longitudinal plate portion 113 of the support member 110. Furthermore, the bearing 51 is disposed at a location between the one side longitudinal plate portion 112 and the other side longitudinal plate portion 113 where the distance from the fixing portion 111 is closer than the distance from the motor 20. Thus, a portion of the height range of the light-emitting module 100 includes both the motor 20 and the bearing 51. Alternatively, although not shown, it is possible that only the motor 20 or only the bearing 51 is included within the height range of the light-emitting module 100.

[0144] The rotary drive unit consists of at least a motor 20, a bearing 51, and an encoder 52. In addition, the motor 20 is fixed to a wall (lower wall 401 and annular wall 404) adjacent to the light-receiving surface which is provided with a light-projecting window 402a through which slit light passes and a light-receiving window 402b through which reflected light passes (also collectively referred to as light-projecting and light-receiving windows).

[0145] In this embodiment, the light-emitting and light-receiving window is composed of a light-emitting window 402a and a light-receiving window 402b, which are independent of each other. However, the light-emitting window and the light-receiving window can also be formed integrally. Furthermore, the light-emitting and light-receiving surface is the surface that forms the outer shape of the housing 400 and has the light-emitting and light-receiving window provided therein, such as... Figure 4 , Figure 17 That is a surface formed by multiple planes formed by the windows. In the case where the light-emitting and light-receiving windows are formed as a single unit, the light-emitting and light-receiving surface can also be a surface formed by a single plane formed by the light-emitting and light-receiving windows.

[0146] The support member 110 supports the light-emitting and light-receiving module 100 in such a way that the module lies within a plane orthogonal to the X direction and containing the rotation drive unit. The support member 110 has a first portion (e.g., a fixing portion 111) and a second portion (e.g., a light-concentrating portion holding portion 114 and a light-emitting portion holding portion 115) formed by multiple curved portions 110A at different heights in the rotation axis direction. In at least a portion of the cross-section containing the rotation axis, the rotation drive unit and the light-emitting and light-receiving module 100 exist between the plane formed by the first portion and the plane formed by the second portion. This structure improves the rigidity of the support member 110 and reduces the thickness of the housing 400 in the X direction.

[0147] Alternatively, although not shown, the encoder 52 may also be included within the height range of the light-emitting and light-receiving module 100. For example, the encoder 52 may be positioned at the middle or upper end of the rotating shaft 50, thereby including the encoder 52 within the height range of the light-emitting and light-receiving module 100. It is also possible that only the encoder 52 is included within the height range of the light-emitting and light-receiving module 100, or that only the motor 20 and the encoder 52 are included within the height range of the light-emitting and light-receiving module 100, or that only the bearing 51 and the encoder 52 are included within the height range of the light-emitting and light-receiving module 100.

[0148] The light-receiving side reflector 15 is disposed on the YZ plane in the optical path between the light-concentrating part 12 and the light-receiving window 402b of the housing 400, so that the reflected light S2 transmitted through the light-receiving window 402b is reflected toward the light-concentrating part 12. That is, the light-concentrating part 12 is disposed on the YZ plane in the optical path between the light-receiving side reflector 15 and the imaging part 13, so that the reflected light S2 after being reflected by the light-receiving side reflector 15 is converged and incident on the imaging part 13. As a result, the reflected light S2 can be refracted toward the light-projecting part 11, so that the distance between the imaging part 13 or the light-concentrating part 12 on the YZ plane and the rotation axis 50 of the light-projecting and light-receiving module 100 is shortened.

[0149] (A variation of Implementation Method 2)

[0150] Figure 19This is a diagram showing the optical displacement meter 1 according to a variation of Embodiment 2. In this variation, the light-receiving side reflective member 15 is omitted. The light-concentrating part 12 is configured such that the optical axis of the light-concentrating part 12 faces the light-receiving window 402b of the housing 400, thereby eliminating the need for the reflective member 15.

[0151] Furthermore, this modified example is an example of a layout where the distance between the light-projecting part 11 and the light-concentrating part 12 is ensured to be wide. For example, this modified example can be applied when the installation distance is relatively long.

[0152] The above-described embodiments are merely illustrative in all respects and are not intended to be limiting. Furthermore, any modifications or alterations falling within the scope of the claims are also modifications or alterations within the scope of this invention. For example, in Embodiment 2, a light-projecting side reflective member may also be provided. Additionally, in Embodiment 2, a deceleration mechanism may also be included. Furthermore, in Embodiments 1 and 2, the motor 20 may be disposed outside the housings 40 and 400. Furthermore, in Embodiment 2, a local area F3 (in which the pixel signal of the image sensor 13a is read) may also be applied. Figure 11 , Figure 12 (As shown in the figure) is a structure that changes in accordance with the rotation angle of the light-emitting and light-receiving module 10.

[0153] Industrial availability

[0154] As explained above, the optical displacement gauge disclosed herein can be used, for example, to acquire data on the three-dimensional shape of a workpiece.

[0155] Explanation of reference numerals in the attached figures

[0156] 1: Optical displacement gauge; 10, 100: Light projection and light receiving modules; 11: Light projection unit; 12: Light receiving lens; 13: Camera unit; 20: Motor; 30: Motor control unit (computation unit); 32: Signal processing unit; W: Workpiece.

Claims

1. An optical displacement meter, which measures the cross-sectional profile of a workpiece with height in the Z direction based on the principle of triangulation, and measures the three-dimensional shape of the workpiece in a manner that does not involve relative movement to the workpiece, characterized in that... have: The projection section irradiates the workpiece with slit light extending in the X direction; A light-receiving lens that converges the reflected light obtained by the workpiece; An image sensor that receives reflected light that has been focused by the light-receiving lens; A support member is provided for fixing the light-projecting part, the light-receiving lens, and the image sensor, and for holding the light-projecting part, the light-receiving lens, and the image sensor together in a manner that satisfies the Schahm relationship; A motor that causes the support member to rotate in a state that maintains the Sham relationship; The control unit controls the motor to scan the slit light in a direction orthogonal to the X direction; A camera control unit that controls the image sensor; as well as The signal processing unit generates the cross-sectional profile of the motor at each rotation angle based on the amount of light received by the image sensor. The plane formed by the slit light illuminating the workpiece is always on the same plane as the focal plane formed by the light-receiving lens and the image sensor, regardless of the rotation angle, and is separated from the rotation axis when viewed from the direction of the rotation axis of the support member. The camera control unit, based on a local area for reading the amount of light received by the image sensor predetermined according to each rotation angle, changes the local area to correspond to the measurement range that varies according to each rotation angle but is focused due to the relationship of the Sham, and establishes a corresponding local area according to each rotation angle.

2. The optical displacement meter according to claim 1, characterized in that, By rotating the support member, a measurable range is formed in a roughly circular arc shape with a predetermined depth, centered on the rotation axis of the support member. The camera control unit varies the local area by each rotation angle so that the area within the measurable range where the amount of light received is read includes a common height in the Z direction.

3. The optical displacement meter according to claim 2, characterized in that, The camera control unit changes the local area by each rotation angle so that the area in the measurable range where the amount of light received is read is approximately consistent in the Z direction from one end of the generally arc-shaped structure to the other.

4. The optical displacement meter according to claim 1, characterized in that, The camera control unit ensures that the number of pixels read from the local area at each rotation angle is the same in the V direction of the image sensor.

5. The optical displacement meter according to claim 1, characterized in that, The camera control unit determines the local area based on each rotation angle and the height of the workpiece corresponding to each rotation angle, in a manner that includes the position of the image sensor in the V direction corresponding to the height of the workpiece.

6. The optical displacement meter according to any one of claims 1 to 5, characterized in that, Before operation, the camera control unit determines the correspondence between each rotation angle and the height of the workpiece based on information obtained by measuring the workpiece using an area encompassing the local region but wider than that local region from the image sensor. After the operation begins, the camera control unit determines the local area based on the correspondence, according to the rotation angle, in a manner that includes the position of the image sensor in the V direction corresponding to the height of the workpiece.

7. The optical displacement meter according to any one of claims 1 to 5, characterized in that, Before operation, the camera control unit determines the correspondence between each rotation angle and the height of the workpiece based on the actual size data or design data of the workpiece. After the operation begins, the camera control unit determines the local area based on the correspondence, according to the rotation angle, in a manner that includes the position of the image sensor in the V direction corresponding to the height of the workpiece.

8. The optical displacement meter according to any one of claims 1 to 5, characterized in that, The local area used to read the amount of light received by the image sensor is predetermined according to the rotation angles before the scanning of the slit light begins.

9. The optical displacement meter according to any one of claims 1 to 5, characterized in that, The control unit simultaneously causes the support member to oscillate around the rotation axis via the motor while the slit light scans. The local area used to read the amount of light received by the image sensor is predetermined according to the rotation angles before the scanning of the slit light in one direction of the oscillating motion begins.

Images