Optical displacement meter

Abstract

To suppress influence on a connection portion for connecting a rotation drive unit and a fixing unit by rotation drive.SOLUTION: An optical displacement meter includes: a light emitting and receiving module having a light projecting unit for irradiating a work with slit light extending in an X direction, a light receiving lens for collecting reflected light from the work, and an imaging unit for receiving the light collected by the light receiving lens; a motor configured to integrally rotate the light emitting and receiving module; a housing configured to house the light emitting and receiving module; a fixed substrate configured to be fixed to the housing; and a first flexible printed circuit board configured to connect the light emitting and receiving module and the fixed substrate. The first flexible printed circuit board has a bent portion in the entire first angle range of a measurement target of the light projecting and receiving module.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to an optical displacement meter. [Background technology]

[0002] When a conventional optical displacement meter is used to obtain two-dimensional profiles of the XZ cross section at different positions in the Y direction of a measurement target (workpiece) and generate three-dimensional shape data from these two-dimensional profiles, the conventional optical displacement meter must move in the Y direction relative to the workpiece. This requires equipment such as a conveyor for transporting the workpiece and a linear motion mechanism for moving the conventional optical displacement meter body relative to the workpiece. However, the introduction of the above-mentioned equipment can be hindered by installation space, cost, and other factors. In addition, when a conventional optical displacement meter is moved by a linear motion mechanism, the cable connecting the conventional optical displacement meter to an external device can break due to bending fatigue.

[0003] On the other hand, an optical displacement meter that rotates a light projection system and a light receiving system is known as an optical displacement meter that does not require the above-mentioned equipment, can acquire two-dimensional profiles of the XZ cross section at different positions in the Y direction of the workpiece, and can generate three-dimensional shape data from these two-dimensional profiles (see Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] European Patent Application Publication No. 3232152 [Patent Document 2] China Utility Model No. 210664364 Summary of the Invention [Problem to be solved by the invention]

[0005] The optical displacement meter that rotates the light projection system and the light receiving system is configured to include a rotation drive unit and a fixed unit. It is expected that the connection portion that connects the rotation drive unit and the fixed unit will be affected by the rotation drive.

[0006] However, in Patent Documents 1 and 2, no measures are taken against the effect of the rotational drive on the connection portion that connects the rotational drive portion and the fixed portion.

[0007] In view of the above problems, an object of the present invention is to provide an optical displacement meter capable of suppressing the influence of rotational drive on a connection portion that connects a rotational drive portion and a fixed portion. [Means for solving the problem]

[0008] The optical displacement meter of the present invention includes, for example, a light-projecting and receiving module having a light-projecting unit that irradiates a workpiece with a slit light extending in the X direction, a light-receiving lens that collects reflected light from the workpiece, and an imaging unit that receives the light collected by the light-receiving lens; a motor that rotates the light-projecting and receiving module as a unit; a housing that stores the light-projecting and receiving module; a fixed substrate fixed to the housing; and a first flexible printed circuit board that connects the light-projecting and receiving module and the fixed substrate, wherein the first flexible printed circuit board has a bent portion throughout a first angle range of the object to be measured by the light-projecting and receiving module.

[0009] However, other features, elements, steps, advantages, and characteristics will become more apparent from the detailed description that follows and the accompanying drawings related thereto. Effect of the Invention

[0010] According to the present invention, it is possible to provide an optical displacement meter capable of suppressing the influence of rotational drive on a connection portion that connects a rotational drive portion and a fixed portion. [Brief description of the drawings]

[0011] [Figure 1] Diagram explaining the optical displacement measurement system [Diagram 2] Diagram explaining the principle of triangulation [Diagram 3] FIG. 1 is a diagram illustrating an optical displacement meter having a reflecting member. [Figure 4] A diagram explaining a method for detecting peak positions [Diagram 5] Functional block diagram of optical displacement sensor [Figure 6] FIG. 1 is a diagram illustrating a first example of a motor arrangement. [Figure 7] FIG. 1 is a diagram illustrating a first example of a motor arrangement. [Figure 8] FIG. 2 is a diagram illustrating a second example of motor arrangement. [Figure 9] FIG. 2 is a diagram illustrating a second example of motor arrangement. [Figure 10] FIG. 1 is a diagram showing a process flow of the measurement operation of the optical displacement measurement system. [Figure 11] FIG. 2 is a diagram illustrating a housing, a fixed substrate, an optical transmitter / receiver module, and a first flexible printed circuit board. [Figure 12] FIG. 1 shows a first flexible substrate [Figure 13] A schematic diagram of the second guide DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] <Optical displacement measurement system> 1 is a diagram showing a schematic configuration example of an optical displacement measurement system 100 of this configuration example, which includes an optical displacement meter 1, a control device 2, a display device 3, and an input device 4.

[0013] In this configuration example, the X direction corresponds to the width direction of the slit light L1 output from the optical displacement meter 1, the Z direction corresponds to the height direction of the workpiece W, and the Y direction corresponds to the direction in which the slit light L1 moves due to the rotation of the light projector (not shown in FIG. 1). The XZ plane described below is a plane extending in the X and Z directions. Since the optical displacement meter 1 scans the slit light L1 by rotating the light projector / receiver module 20, the scanning direction of the slit light L1 is a direction perpendicular to the X direction in the YZ plane, including the Y direction. In this specification, "rotation" refers to a swinging motion that reciprocates around a rotation axis.

[0014] The optical displacement measurement system 100 is a system that measures the profile and three-dimensional shape of the workpiece W. The profile of the workpiece W is data indicating the outer edge of the cut surface of the workpiece W by the slit light L1. When the slit light is irradiated parallel to the XZ plane, the profile of the workpiece W becomes data indicating the outer edge of the cut surface parallel to the XZ plane, and is therefore also called a two-dimensional profile of the XZ cross section of the workpiece W.

[0015] For example, a profile is a collection of (xi,zi) (i is the index). xi indicates the position in the X direction. zi indicates the height in the Z direction. A three-dimensional shape is a collection of (xi,yi,zi). yi indicates the position in the Y direction.

[0016] The optical displacement meter 1 operates according to instructions from the control device 2. The optical displacement meter 1 outputs a slit light L1 extending in the X direction and receives reflected light L2 from the workpiece W. The optical displacement meter 1 then calculates a profile of the workpiece W based on the light reception result. The optical displacement meter 1 performs imaging at regular intervals to generate profiles of the workpiece W with different yi. In addition, the optical displacement meter 1 generates three-dimensional shape data of the workpiece W from the profiles of the workpiece W with different yi.

[0017] The control device 2 outputs instructions based on user input received by the input device 4 to the optical displacement meter 1, and receives measurement results of the workpiece W from the optical displacement meter 1. The control device 2 also outputs a display signal to the display device 3. The control device 2 is, for example, a personal computer, a programmable logic controller, or the like.

[0018] Based on a display signal from the control device 2, the display device 3 displays, for example, the measurement results of the workpiece W, a UI (user interface) for setting the optical displacement meter 1, and the like.

[0019] The input device 4 accepts a user input to the optical displacement measurement system 100. In Fig. 1, a keyboard and a mouse are illustrated as the input device 4. However, the input device 4 is not limited to a keyboard and a mouse. For example, the input device 4 may be a touch panel arranged on the display screen of the display device 3.

[0020] 2 is a diagram explaining the principle of the light cutting method (triangulation distance measurement). A light projecting unit 11, a light receiving lens 12, and an imaging unit 13 are stored inside a housing 10 of the optical displacement meter 1. The light projecting unit 11 has a light source 14 and a light projecting lens 15. For example, the light source 14 may be a laser light emitter, and the light projecting lens 15 may be composed of a plurality of lenses including a cylindrical lens.

[0021] The light output from the light source 14 is converted into slit light L1 by passing through a light projecting lens 15. The housing 10 is provided with a light projecting window 16 having a light transmitting property that allows the slit light L1 to pass therethrough. Similarly, the housing 10 is provided with a light receiving window 17 having a light transmitting property that allows the reflected light L2 to pass therethrough.

[0022] The light receiving lens 12 is a lens for collecting the reflected light L2 and forming an image on the light receiving surface of the imaging unit 13. The light receiving lens 12 may be configured to include only one lens, or may be configured to include multiple lenses. The light receiving lens 12 may also be configured to include optical components other than lenses (e.g., optical filters, etc.). The imaging unit 13 is an image sensor having multiple photoelectric conversion elements arranged two-dimensionally. The imaging unit 13 receives the light collected by the light receiving lens.

[0023] As shown in FIG. 2, the optical axis AX2 of the light receiving lens 12 is inclined with respect to the projection axis AX1 of the light projecting unit 11. The projection axis AX1 of the light projecting unit 11 coincides with the optical axis of the light source 14. As a result, the reflected light L2 from the height Z1 forms an image at a position V1 in the V direction on the light receiving surface of the imaging unit 13, and the reflected light L2 from the height Z2 forms an image at a position V2 in the V direction on the light receiving surface of the imaging unit 13. That is, the V direction of the light receiving surface of the imaging unit 13 corresponds to the Z direction of the workpiece W. Although the U direction of the light receiving surface of the imaging unit 13 is not shown, the U direction corresponds to the X direction of the workpiece W. That is, the vertical direction of the image, which is the light receiving result output by the imaging unit 13, is the V direction, and the horizontal direction is the U direction.

[0024] Light projecting unit 11, light receiving lens 12, and imaging unit 13 are rotatable about rotation axis AX3 along the X direction. The relative positions of light projecting unit 11, light receiving lens 12, and imaging unit 13 are fixed. In Fig. 2, the states of light projecting unit 11, light receiving lens 12, and imaging unit 13 before rotation in the counterclockwise direction CCW are illustrated by solid lines, and the states after rotation in the counterclockwise direction CCW are illustrated by dashed lines.

[0025] The light projecting unit 11, the light receiving lens 12, and the imaging unit 13 can rotate about a rotation axis AX3 along the X direction while satisfying the Scheimpflug relationship in which the light receiving surface of the imaging unit 13 is inclined with respect to the optical axis of the light receiving lens 12. This allows the image to be in focus at each cross section through which the light projecting axis AX1 passes in the shaded area R1 in Fig. 2. In other words, the optical displacement meter 1 can generate a focused profile of the workpiece W even if the height of the workpiece W changes.

[0026] The positional relationship between light projecting unit 11, light receiving lens 12, and imaging unit 13 may be reversed from that shown in FIG.

[0027] 3, the optical displacement meter 1 may further include a reflecting member 18. The reflecting member 18 is provided on the optical path between the light receiving window 17 and the imaging unit 13, and folds back the reflected light L2 and the optical axis AX2 of the light receiving lens 12 toward the light projecting unit 11. This allows the light projecting and receiving module that integrally holds the light projecting unit 11, the light receiving lens 12, the imaging unit 13, and the reflecting member 18 to be configured compactly in the YZ plane extending in the Y and Z directions. This allows the moment of inertia around the rotation axis AX3 of the light projecting and receiving module that integrally holds the light projecting unit 11, the light receiving lens 12, the imaging unit 13, and the reflecting member 18 to be reduced.

[0028] In FIG. 3, the reflecting member 18 is provided on the optical path between the light receiving lens 12 and the imaging section 13, but it may also be provided on the optical path between the light receiving window 17 and the light receiving lens 12 (see, for example, FIG. 8 and FIG. 9 described later).

[0029] When the reflecting member 18 is provided on the optical path between the light-receiving lens 12 and the imaging unit 13, the reflecting member 18 reflects the light after being collected by the light-receiving lens 12, and therefore it is possible to reduce the area of ​​the reflecting surface of the reflecting member 18. When the reflecting member 18 is provided on the optical path between the light-receiving window 17 and the light-receiving lens 12, the heavy light-receiving lens 12 can be disposed closer to the rotation axis AX3, which increases the effect of reducing the moment of inertia.

[0030] <Position (height calculation)> 4 is a diagram for explaining a method for calculating the heights constituting the profile from image I1, which is the light reception result output by image capture unit 13. Slit light L1 has a certain width in the Y direction. Therefore, the width of the light spot brought about by reflected light L2 on the light receiving surface of image capture unit 13 also becomes a width that spans multiple photoelectric conversion elements.

[0031] Therefore, the optical displacement meter 1 obtains an approximation curve P1 indicating the change in luminance value from the luminance value of each pixel, and calculates the position in the V direction that brings about the peak value on the approximation curve P1. In FIG. 4, the leftmost column is the column of interest, and the distribution of luminance values ​​of the column of interest (approximation curve P1) is illustrated. The approximation curve P1 is obtained by curve fitting a plurality of sample values, etc. Sample values ​​below the detection threshold are not taken into consideration. The position in the V direction that brings about this peak value indicates the height of the workpiece W. The optical displacement meter 1 obtains an approximation curve P1 at each position (each pixel column) in the U direction, and calculates the position (height) in the V direction that brings about the peak value from the approximation curve P1. By performing this calculation process at each position in the U direction, one profile is obtained. Such calculation process may be called sub-pixel processing.

[0032] Note that, for example, by calibration before shipment, coordinate conversion conditions (e.g., a coordinate conversion table) indicating the correspondence between the UV coordinates and rotation angle θ, as expressed by (U, V, θ)=(X, Y, Z), and the local coordinates (X, Y, Z) are generated and stored in a memory unit (not shown) of the optical displacement meter 1. Therefore, the optical displacement meter 1 can convert the profile in the UV coordinate system to the XYZ coordinate system based on the rotation angle θ through simple calculations.

[0033] <Function block> 5 is a functional block diagram of the optical displacement meter 1. The optical displacement meter 1 includes a light emitting and receiving module 20, a motor 21, and a control unit 22.

[0034] The light projecting and receiving module 20 integrally holds the light projecting unit 11, the light receiving lens 12, and the imaging unit 13. Furthermore, in the case where the optical displacement meter 1 is equipped with a reflecting member 18, the light projecting and receiving module 20 integrally holds the light projecting unit 11, the light receiving lens 12, the imaging unit 13, and the reflecting member 18 (not shown in FIG. 5). The light projecting and receiving module 20 is stored in the housing 10.

[0035] The motor 21 rotates the light projecting unit 11, the light receiving lens 12, and the imaging unit 13. More specifically, the motor 21 rotates the light projecting and receiving module 20. The motor 21 may rotate the light projecting and receiving module 20 by a direct drive method in which no intermediate mechanism such as a reducer is disposed between the motor 21 and the light projecting and receiving module 20, or may rotate the light projecting and receiving module 20 via an intermediate mechanism such as a reducer.

[0036] The control unit 22 includes a motor control unit 23, a signal processing unit 24, and a communication unit 25. The control unit 22 controls the motor 21 to rotate the light projecting unit 11, the light receiving lens 12, and the imaging unit 13 in a state where the Scheimpflug relationship is satisfied, and scans the slit light L1 in a direction perpendicular to the X direction. More specifically, the motor control unit 23 controls the motor 21 to rotate the light projecting unit 11, the light receiving lens 12, and the imaging unit 13 in a state where the Scheimpflug relationship is satisfied, and the signal processing unit 24 controls the light projecting unit 11 to irradiate the slit light L1 from the light projecting unit 11.

[0037] The signal processing unit 24 includes a peak detection unit 26, a profile generation unit 27, and a three-dimensional data generation unit 28. The peak detection unit 26 detects a position (peak position) in the V direction that brings about a peak in the luminance value based on the light reception result output from the imaging unit 13. The profile generation unit 27 generates one profile data by collecting the heights (zi) of the workpiece W at each position (xi) in the X direction obtained by the peak detection unit 26. The three-dimensional data generation unit 28 generates three-dimensional shape data of the workpiece W from the profiles of the workpiece W having different yi generated by the profile generation unit 27. At least a part of the peak detection unit 26, the profile generation unit 27, and the three-dimensional data generation unit 28 may be provided inside the control device 2 (see FIG. 1) instead of inside the optical displacement meter 1.

[0038] The communication unit 25 performs wired or wireless communication with the control device 2. For example, the communication unit 25 receives instructions from the control device 2 and transmits them to the control unit 22. In addition, the communication unit 25 transmits, for example, profile data and three-dimensional shape data of the workpiece W generated by the signal processing unit 24 to the control device 2.

[0039] <Motor placement> Figures 6 and 7 are diagrams for explaining a first example of the arrangement of the motor 21. Figure 6 is a cross-sectional view perpendicular to the X direction of the optical displacement meter 1 taken along line BB' in Figure 7. Figure 7 is a cross-sectional view along the XZ plane of the optical displacement meter 1 taken along line AA' in Figure 6.

[0040] In the first example, the light emitting and receiving module 20 includes a plate-shaped base member 201 extending along a plane perpendicular to the X direction. The light emitting unit 11, the light receiving lens 12, the imaging unit 13, and the reflecting member 18 are mounted on the base member 201.

[0041] In the first example, the light projecting and receiving module 20 does not overlap with the motor 21 and the accessories of the motor 21 in the X direction. The accessories of the motor 21 are, for example, an encoder that detects the amount of rotation of the rotor of the motor 21. According to the first example of the arrangement of the motor 21, it is easy to arrange the light projecting unit 11, the light receiving lens 12, and the imaging unit 13 close to each other. By arranging the light projecting unit 11, the light receiving lens 12, and the imaging unit 13 close to each other, the light projecting and receiving module 20 can be configured to be compact. Therefore, the moment of inertia around the rotation axis AX3 of the light projecting and receiving module 20 can be reduced.

[0042] In the first example, the control unit 22 does not overlap with the light emitting and receiving module 20 in the X direction, but overlaps with the motor 21 in the X direction.

[0043] Figures 8 and 9 are diagrams for explaining a second example of the arrangement of the motor 21. Figure 8 is a cross-sectional view perpendicular to the X direction of the optical displacement gauge 1 taken along line BB' in Figure 9. Figure 9 is a cross-sectional view perpendicular to the Z direction of the optical displacement gauge 1 taken along line AA' in Figure 8.

[0044] In the second example, the light emitting / receiving module 20 includes a base member 201. The base member 201 includes a tube portion extending along the X direction, a cover portion closing one end of the tube portion in the X direction, and a flange portion extending radially outward from the other end of the tube portion in the X direction. The light emitting unit 11, the light receiving lens 12, the imaging unit 13, and the reflecting member 18 are mounted on the flange portion of the base member 201.

[0045] In the second example, the light-emitting / receiving module 20 overlaps with at least one of the motor 21 and an accessory of the motor 21 in the X direction. As in the first example, the accessory of the motor 21 is, for example, an encoder that detects the amount of rotation of the rotor of the motor 21. According to the second example of the arrangement of the motor 21, it becomes easy to arrange the light-emitting unit 11 away from the light-receiving lens 12 and the imaging unit 13. By separating the light-emitting unit 11 from the light-receiving lens 12 and the imaging unit 13, the scanning range of the slit light L1 can be expanded.

[0046] Furthermore, in the second example, the control unit 22 overlaps with the light emitting and receiving module 20 and the motor 21 in the X direction. Note that the control unit 22 may be disposed in a position that does not overlap with the motor 21 in the X direction but overlaps with the motor 21 as viewed from the X direction. When the control unit 22 is disposed in a position that does not overlap with the motor 21 in the X direction but overlaps with the motor 21 as viewed from the X direction, the control unit 22 may or may not overlap with the light emitting and receiving module 20 and the motor 21 in the X direction.

[0047] <Processing flow> Fig. 10 is a diagram showing a process flow of the measurement operation of the optical displacement measurement system 100. When the input device 4 receives a user input instructing the start of measurement, the process flow of Fig. 10 starts.

[0048] First, in step S1, the light projector 11 starts emitting the slit light L1. In the following step S2, the motor control unit 23 starts rotating the motor 21. Note that the processing of step S1 and the processing of step S2 may be executed simultaneously. Before executing step S1, the motor control unit 23 may rotate the motor to move the light projector / receive module 20 to a predetermined scanning start position. The processing of steps S1 and S2 starts scanning with the slit light L1.

[0049] In the next step S3, the motor control unit 23 determines whether the amount of rotation (rotation angle) of the motor 21 from the start of rotation is smaller than a threshold value. If the amount of rotation of the motor 21 from the start of rotation is smaller than the threshold value, the determination process of step S3 continues, and the scanning of the slit light L1 continues.

[0050] When the amount of rotation of the motor 21 from the start of rotation reaches the threshold, the flow proceeds to step S4. The threshold is the amount of rotation calculated based on the measurement range. The measurement range is set as a default, and when the measurement range is changed by the user, the control unit 22 (e.g., the signal processing unit 24) calculates the threshold of the amount of rotation based on the measurement range after the change.

[0051] In step S4, motor control unit 23 stops the rotation of motor 21. In the following step S5, light projector 11 stops emitting slit light L1. Note that steps S4 and S5 may be performed simultaneously. The scanning of slit light L1 is completed by the processes of steps S4 and S5.

[0052] In the next step S6, the profile generator 27 generates a profile. The profile generator 27 may start generating a profile during scanning with the slit light L1.

[0053] In the following step S7, the three-dimensional data generator 28 generates three-dimensional data.

[0054] In the following step S8, the display device 3 displays the measurement results. The measurement results are, for example, a cross-sectional view of the workpiece W based on the profile, a three-dimensional image of the workpiece W based on the three-dimensional data, etc. When the process of step S8 ends, the process flow of FIG. 10 ends.

[0055] The optical displacement meter 1 has a measurement period in which the measurement operation is performed by rotating the light emitting and receiving module 20 at a substantially constant speed in a first rotation direction (counterclockwise direction CCW) or a second rotation direction (clockwise direction CW), and a non-measurement period in which the measurement operation is not performed while switching the rotation direction of the light emitting and receiving module 20 is performed. In the measurement period in which the measurement operation is performed, the motor rotates the light emitting and receiving module 20 at a substantially constant speed in a first angle range described later. In the period in which the rotation direction is switched in a second angle range described later, deceleration and acceleration must be taken into consideration, and calculations such as the correlation between the peak position in the V direction and the rotation angle become complicated, so it is preferable to use the non-measurement period.

[0056] <Connection between the light emitting / receiving module and the fixed board> 11 is a diagram illustrating the housing 10, the light emitting and receiving module 20, the fixed substrate 30, and the first flexible printed circuit board 31. The optical displacement meter 1 further includes the fixed substrate 30 and the first flexible printed circuit board 31.

[0057] The fixed substrate 30 is fixed to the housing 10. The fixed substrate 30 may be directly fixed to the housing 10, or may be fixed to the housing 10 via another member. The fixed substrate 30 may be configured to include, for example, a profile generating unit 27. The fixed substrate 30 may also be configured to include, for example, a three-dimensional data generating unit 28 in addition to the profile generating unit 27. If the fixed substrate 30 is configured to include the profile generating unit 27 and the three-dimensional data generating unit 28, heat generated in the profile generating unit 27 and the three-dimensional data generating unit 28 can be easily dissipated.

[0058] In addition, the first modification of this embodiment may be configured such that the light emitting / receiving module 20 is provided with a signal processing section 24 (for example, a signal processing board), and the first flexible printed circuit board 31 electrically connects the signal processing section 24 and the fixed board 30. In the optical displacement meter of the first modification, the light emitting / receiving module 20 may be configured to include a profile generating section 27, or may further include a three-dimensional data generating section 28. The profile generating section 27 and the three-dimensional data generating section 28 in the first modification may be provided on the same signal processing board, or may be provided on separate signal processing boards electrically connected to each other. The second modification of this embodiment may be a measurement system in which a control section of an external device (for example, the control device 2 in FIG. 1) connected to the optical displacement meter 1 executes the function of the signal processing section 24. In the measurement system of the second modification, the control section of the external device may execute the function of the profile generating section 27, or may further execute the function of the three-dimensional data generating section 28. A third modification of this embodiment may be configured such that the light emitting / receiving module 20 generates a two-dimensional profile, and the fixed substrate 30 or a control unit of the external device generates three-dimensional data from the two-dimensional profile. A fourth modification of this embodiment may be configured such that the fixed substrate 30 generates a two-dimensional profile, and the control unit of the external device generates three-dimensional data from the two-dimensional profile.

[0059] The fixed substrate 30 may be configured to include, for example, a motor control unit 23. The fixed substrate 30 may be configured to include, for example, a communication unit 25. The fixed substrate 30 may be configured with a single substrate or multiple substrates.

[0060] The direction of the mounting surface of the fixed substrate 30 on which the electronic components are mounted is not particularly limited, and may be, for example, perpendicular to the X direction, or may be, for example, parallel to the X direction.

[0061] The first flexible printed circuit board 31 connects the light emitting and receiving module 20 and the fixed substrate 30. The first flexible printed circuit board 31 has a bent portion and maintains a bent state throughout the first angle range of the measurement target of the light emitting and receiving module 20. When the light emitting and receiving module 20 rotates in the clockwise direction CW, the bent portion 311 (portion maintaining the bent state) of the first flexible printed circuit board 31 moves in a first direction D1 shown in FIG. 11. Conversely, when the light emitting and receiving module 20 rotates in the counterclockwise direction CCW, the bent portion 311 of the first flexible printed circuit board 31 moves in a second direction D2 shown in FIG. 11.

[0062] The bent state of the first flexible printed circuit board 31 may be a shape along a two-dimensional curve or a shape along a three-dimensional curve. Unlike the example shown in Fig. 11, an example of a case where the bent state of the first flexible printed circuit board 31 is a shape along a three-dimensional curve is depicted in Fig. 12. The first flexible printed circuit board 31 shown in Fig. 12 has a spiral shape and is configured to be capable of at least one of twisting and expanding and contracting along the rotation axis AX3 of the light emitting and receiving module 20.

[0063] Here, the first angle range of the measurement target means an angle range that is set so that image processing proceeds at least until three-dimensional data generation by three-dimensional data generation unit 28 has generated three-dimensional data.

[0064] Since the first flexible printed circuit board 31 maintains a bent state throughout the entire first angle range of the object to be measured by the light projecting and receiving module 20, the optical displacement meter 1 can increase the durability of the connection portion between the light projecting and receiving module 20 and the fixed substrate 30 against rotation of the light projecting and receiving module 20 during measurement operation.

[0065] It is preferable that the radius of curvature of the bent portion 311 of the first flexible printed circuit board 31 is substantially the same throughout the first angle range. With this configuration, it is possible to suppress changes in the stress distribution of the bent portion 311 due to the rotation of the light emitting and receiving module 20, and therefore it is possible to suppress the occurrence of bending fatigue in the bent portion 311. Here, "substantially the same" means within +2 mm, and more preferably within +1 mm, of the radius of curvature of the bent portion 311 when the rotation angle of the light emitting and receiving module 20 is at the center of the first angle range.

[0066] Throughout the first angle range of the measurement target, the portion of the first flexible printed circuit board 31 that maintains the bent state moves outside the area in the housing 10 where the light emitting and receiving module 20 is arranged. The internal space of the housing 10 may be divided into a first area where the fixed substrate 30 is arranged and a second area where the light emitting and receiving module 20 is arranged, and the first flexible printed circuit board 31 may move between the first area and the second area. With this configuration, even if the light emitting and receiving module 20 rotates, it is possible to prevent the first flexible printed circuit board 31 from interfering with the rotation of the light emitting and receiving module 20. In addition, the optical displacement meter 1 can prevent contact between the fixed substrate 30 and the light emitting and receiving module 20.

[0067] The optical displacement meter 1 further includes an imaging board 32 that controls the imaging unit 13. The light projecting and receiving module 20 further integrally holds the imaging board 32. Therefore, the imaging board 32 is a part of the light projecting and receiving module 20. The direction of the mounting surface of the imaging board 32 on which electronic components are mounted is not particularly limited, and may be, for example, perpendicular to the X direction or parallel to the X direction.

[0068] The first flexible printed circuit board 31 electrically connects the imaging board 32 and the fixed board 30. The imaging board 32 and the fixed board 30 may be directly connected by the first flexible printed circuit board 31, or may be indirectly connected via the first flexible printed circuit board 31 and another board.

[0069] <Guide> 11, the optical displacement meter 1 further includes a guide structure for changing the position of the bent portion in the first flexible printed circuit board 31 with the rotation of the light emitting and receiving module 20, and for keeping within a predetermined range the change in the radius of curvature of the bent portion caused by the rotation of the light emitting and receiving module 20 over the entire first angle range. With this configuration, the change in the radius of curvature can be kept within a predetermined range to prevent excessive stress concentration. The guide structure includes a first guide 33 and a second guide 34.

[0070] The first guide 33 may be fixed directly to the housing 10, or may be fixed to the housing 10 via another member. In the example shown in Fig. 11, the first guide 33 is fixed to the housing 10 via a fixed substrate 30. The first guide 33 extends along the direction of the rotation axis AX3 of the light emitting and receiving module 20.

[0071] The second guide 34 is rotated integrally with the light emitting and receiving module 20 by the motor 21. The second guide 34 extends along the direction of the rotation axis AX3 of the light emitting and receiving module 20.

[0072] The first portion 312 of the first flexible printed circuit board 31 is guided along the first guide 33. The second portion 313 of the first flexible printed circuit board 31 is guided along the second guide 34. When viewed along the rotation axis direction, the first flexible printed circuit board 31 has a bent portion between the first guide 33 and the second guide 34 in the entire first angle range of the measurement target of the light emitting and receiving module 20, and maintains a bent state. As a result, by guiding the FPC from both the fixed side and the driving side, the movement of the bent portion accompanying the rotation is more stable, and the radius of curvature is also more likely to be within a predetermined range. The first portion 312 of the first flexible printed circuit board 31 contacts the first wall surface of the first guide 33. The second portion 313 of the first flexible printed circuit board 31 contacts the second wall surface of the second guide 34. When viewed along the rotation axis direction, the bent portion forms an approximately U-shape from the first portion 312 to the second portion 313. With this configuration, the contact area between the first wall surface of the first guide 33 and the first portion 312 of the first flexible printed circuit board 31 and the contact area between the second wall surface of the second guide 34 and the second portion 313 of the first flexible printed circuit board 31 only increases and decreases in response to the rotation of the light emitting and receiving module 20. Furthermore, since the contact portion of the first flexible printed circuit board 31 with the guide does not move in the circumferential direction relative to the first wall surface of the first guide 33 and the second wall surface of the second guide 34, the contact portion of the first flexible printed circuit board 31 with the guide does not wear out. Furthermore, with this configuration, the bent portion 311, which is the bent portion of the first flexible printed circuit board 31, can be easily formed.

[0073] The first guide 33 has an arc shape when viewed from the direction of the rotation axis AX3 of the light emitting and receiving module 20, and has a first wall surface that guides the first portion 312. The second guide 34 has an arc shape when viewed from the direction of the rotation axis AX3 of the light emitting and receiving module 20, and has a second wall surface that guides the second portion 313. The first wall surface of the first guide 33 and the second wall surface of the second guide 34 are arranged in a substantially concentric circle centered on the rotation axis AX3 of the light emitting and receiving module 20. This makes it possible to make the radius of curvature uniform, thereby suppressing stress concentration that accompanies changes in the radius of curvature. In addition, since the radius of curvature is maintained, it becomes easier to predict fatigue and evaluate life span.

[0074] The radius of curvature of the second wall surface of the second guide 34 is smaller than the radius of curvature of the first wall surface of the first guide 33 and larger than the radius of curvature of the bent portion 311 of the first flexible printed circuit board 31. This allows the first guide 33 on the fixed side to be disposed on the outer side with respect to the rotation axis AX3 than the second guide 34 on the light emitting / receiving module side, and also allows the radius of curvature of the bent portion to be relatively small, thereby enabling an efficient arrangement.

[0075] <Second flexible printed circuit board> 11, the optical displacement meter 1 further includes a light-projecting board 35 that controls the light-projecting unit 11, and a second flexible printed circuit board 36. The light-projecting and receiving module 20 further integrally holds the light-projecting board 35. Thus, the light-projecting board 35 is a part of the light-projecting and receiving module 20. The direction of the mounting surface on which the electronic components of the light-projecting board 35 are mounted is not particularly limited, and may be, for example, perpendicular to the X direction, or may be, for example, parallel to the X direction.

[0076] Second flexible printed circuit board 36 electrically connects light-projecting board 35 and fixed board 30 together.

[0077] The guiding of the second flexible printed circuit board 36 by the first guide 33 and the second guide 34 is the same as the guiding of the first flexible printed circuit board 31 by the first guide 33 and the second guide 34. That is, the guide structure (for example, the first guide 33 and the second guide 34) provided in the optical displacement meter 1 changes the position of the bent portion in the second flexible printed circuit board 36 with the rotation of the light emitting and receiving module 20, and guides a plurality of flexible printed circuit boards (for example, the first flexible printed circuit board 31 and the second flexible printed circuit board 36) by keeping the change in the radius of curvature of the bent portion caused by the rotation of the light emitting and receiving module 20 in the entire first angle range within a predetermined range. As a result, the light emitting system and the light receiving system rotate integrally, and each flexible printed circuit board moves in the same manner, so that a common guide structure can be used to save space. Note that the relationship between the guide and the flexible printed circuit board is not limited to the example shown in FIG. 11. Therefore, for example, the guide provided in the optical displacement meter 1 may guide a single flexible printed circuit board. In other words, the optical displacement meter 1 may be configured such that a guide structure is provided for each of a plurality of flexible printed circuit boards.

[0078] 13 is a diagram showing a schematic view of the second guide 34. The optical displacement meter 1 further includes a rib structure (protrusion) 331 for preventing contact between the first flexible printed circuit board 31 and the second flexible printed circuit board 36. This makes it possible to suppress the occurrence of short circuits or damage due to contact between the first flexible printed circuit board 31 and the second flexible printed circuit board 36. More specifically, as shown in FIG. 13, the second guide 34 has a rib structure 331. Similarly to the second guide 34, the first guide 33 also has a rib structure 331.

[0079] The optical displacement meter 1 further includes a rib structure (protrusion) 332 that restricts the first flexible printed circuit board 31 from moving in a direction away from the second flexible printed circuit board 36. The rib structure (protrusion) 331 and the rib structure (protrusion) 332 restrict the movement of the first flexible printed circuit board 31 in the X direction.

[0080] The optical displacement meter 1 further includes a rib structure (protrusion) 333 that restricts the second flexible printed circuit board 36 from moving in a direction away from the first flexible printed circuit board 31. The rib structure (protrusion) 331 and the rib structure (protrusion) 333 restrict the movement of the second flexible printed circuit board 36 in the X direction.

[0081] <Angle range of light emitting / receiving module> The light emitting and receiving module 20 may be configured to be rotatable to a second angle range that is outside the first angle range and is not subject to measurement, by rotation of the motor 21. It is preferable that the first flexible printed circuit board 31 maintains the bent state throughout the entire second angle range.

[0082] Here, the second angle range not to be measured refers to an angle range that is set so that image processing does not proceed to the generation of three-dimensional data by the three-dimensional data generating unit 28. Therefore, in the second angle range not to be measured, image processing may proceed to the generation of a profile by the profile generating unit 27, or image processing may not proceed to the generation of a profile by the profile generating unit 27.

[0083] By maintaining the bent state of the first flexible printed circuit board 31 even throughout the entire second angle range, the optical displacement meter 1 can increase the durability of the connection between the light emitting and receiving module 20 and the fixed substrate 30 against rotation of the light emitting and receiving module 20 during, for example, a rotation direction switching operation or a maintenance operation. Note that the maintenance operation is an operation in which the optical displacement meter 1 rotates the motor 21 by making the rotation angle range of the motor 21 larger than that during the measurement operation in order to suppress fretting wear on the bearings of the motor 21.

[0084] <Summary> The various embodiments described above will be generally described below.

[0085] For example, an optical displacement meter disclosed in this specification includes a light-projecting and receiving module having a light-projecting unit that irradiates a workpiece with a slit light extending in the X direction, a light-receiving lens that collects reflected light from the workpiece, and an imaging unit that receives the light collected by the light-receiving lens, a motor that rotates the light-projecting and receiving module as a unit, a housing that stores the light-projecting and receiving module, a fixed substrate fixed to the housing, and a first flexible printed circuit board that connects the light-projecting and receiving module and the fixed substrate, and the first flexible printed circuit board is configured (first configuration) to have a bent portion throughout a first angle range of the object to be measured by the light-projecting and receiving module.

[0086] In the optical displacement meter of the above-mentioned first configuration, the optical displacement meter may be further configured (second configuration) to change the position of the bent portion in the first flexible printed circuit board as the light projecting and receiving module rotates, and to keep the amount of change in the radius of curvature of the bent portion due to rotation of the light projecting and receiving module over the entire first angle range within a predetermined range.

[0087] In an optical displacement meter having any of the first to second configurations described above, the guide structure may have a first guide fixed to the housing and a second guide that rotates integrally with the light emitting and receiving module by the motor, and the first flexible printed circuit board may have the bent portion over the entire first angle range between the first guide and the second guide when viewed along the rotation axis direction (third configuration).

[0088] In an optical displacement meter having any of the above first to third configurations, the first flexible printed circuit board may have a first portion guided along the first guide and a second portion guided along the second guide, and the bent portion may be configured to form an approximately U-shape from the first portion to the second portion when viewed along the rotation axis direction (fourth configuration).

[0089] In the optical displacement gauge having the above first to fourth configurations, the first guide may be arc-shaped when viewed from the direction of the rotation axis of the light projecting and receiving module and have a first wall surface that guides the first portion, the second guide may be arc-shaped when viewed from the direction of the rotation axis of the light projecting and receiving module and have a second wall surface that guides the second portion, and the first wall surface and the second wall surface may be arranged in a substantially concentric circle centered on the rotation axis of the light projecting and receiving module (fifth configuration).

[0090] In the optical displacement gauge having the above first to fifth configurations, the first guide and the second guide may be configured (sixth configuration) to extend along the rotation axis direction of the light emitting and receiving module.

[0091] In an optical displacement meter having any of the above first to sixth configurations, the first flexible printed circuit board electrically connects the imaging unit and the fixed substrate, and the light projecting and receiving module electrically connects the light projecting unit and the fixed substrate and further includes a second flexible printed circuit board having a curved portion throughout the first angle range, and the guide structure may be configured to change the position of the curved portion in the second flexible printed circuit board as the light projecting and receiving module rotates, and to keep the amount of change in the radius of curvature of the curved portion due to the rotation of the light projecting and receiving module throughout the first angle range within a predetermined range (seventh configuration).

[0092] In the optical displacement meter of the seventh configuration described above, the first flexible printed circuit board and the second flexible printed circuit board may be configured (eighth configuration) to be guided together by the guide structure while aligned in the rotation axis direction of the light projector / receiver module.

[0093] In the optical displacement gauge having any of the seventh to eighth configurations above, the guide structure may be configured (ninth configuration) to further have a rib structure that prevents contact between the first flexible printed circuit board and the second flexible printed circuit board.

[0094] In an optical displacement meter having any of the above configurations 1 to 9, the light projector / receiver module is configured to be rotatable by rotation of the motor to a second angle range that is outside the first angle range and is not subject to measurement, and the first flexible printed circuit board may be configured to have the bent portion even throughout the entire second angle range (configuration 10).

[0095] In the optical displacement meter having any of the above-mentioned first to tenth configurations, the first flexible printed circuit board may be configured (eleventh configuration) to have a spiral shape and be capable of at least one of twisting and expanding and contracting along the rotation axis of the light emitting and receiving module.

[0096] In an optical displacement meter having any of the above configurations 1 to 11, the light projector / receiver module is configured to be rotatable by rotation of the motor to a second angle range that is outside the first angle range and is not subject to measurement, and the first flexible printed circuit board may be configured to have a bent portion even throughout the entire second angle range (configuration 12).

[0097] In an optical displacement meter having any of the above-mentioned configurations 1 to 12, the fixed substrate may be configured (configuration 13) to include a profile generating unit that generates a cross-sectional profile of the workpiece at each rotation angle based on the amount of light received by the imaging unit.

[0098] In the optical displacement meter of the 13th configuration described above, the optical displacement meter further includes a three-dimensional data generation unit that generates data of a three-dimensional shape from the multiple cross-sectional profiles obtained by rotating the light projecting and receiving module, and the three-dimensional data generation unit may be provided on the light projecting and receiving module or on the fixed substrate (14th configuration).

[0099] In a measurement system comprising the optical displacement meter described in the above 13 and an external device having a control unit, the optical displacement meter may further comprise a communication unit that transmits the cross-sectional profile generated by the profile generation unit to the external device, and the control unit of the external device may be configured to generate three-dimensional shape data from the multiple cross-sectional profiles received from the optical displacement meter (configuration 15).

[0100] In an optical displacement meter having any of the above-mentioned configurations 1 to 12, the fixed substrate may be configured (configuration 16) to include a profile generating unit that generates a cross-sectional profile of the workpiece at each rotation angle based on the amount of light received by the imaging unit.

[0101] In the optical displacement meter of the 16th configuration described above, the fixed substrate may further include a three-dimensional data generation unit that generates data on a three-dimensional shape from the multiple cross-sectional profiles obtained by rotating the light projecting and receiving module (17th configuration).

[0102] In a measurement system comprising an optical displacement meter of the above-mentioned 16th configuration and an external device having a control unit, the optical displacement meter may further comprise a communication unit that transmits the cross-sectional profile generated by the profile generation unit to the external device, and the control unit of the external device may be configured to generate three-dimensional shape data from the multiple cross-sectional profiles received from the optical displacement meter (18th configuration).

[0103] In a measurement system comprising an optical displacement meter having any one of the configurations 1 to 12 above and an external device having a control unit, the optical displacement meter further comprises a communication unit that transmits data regarding the amount of light received by the imaging unit to the external device, and the control unit of the external device may be configured to generate a two-dimensional profile of the cross section of the work at each rotation angle based on the amount of light received from the optical displacement meter (19th configuration).

[0104] In the measurement system of the 19th configuration above, the communication unit of the optical displacement meter may transmit the multiple cross-sectional profiles obtained by rotating the light emitting and receiving module to the external device, and the control unit of the external device may generate three-dimensional shape data from the multiple cross-sectional profiles received from the optical displacement meter (20th configuration).

[0105] <Other Modifications> In addition to the above-mentioned embodiment, various technical features disclosed in this specification can be modified in various ways without departing from the spirit of the technical creation. In other words, the above-mentioned embodiment should be considered to be illustrative and not restrictive in all respects, and the technical scope of the present invention is defined by the claims, and should be understood to include all modifications that fall within the meaning and scope equivalent to the claims. [Explanation of symbols]

[0106] 1. Optical displacement gauge 2. Control device 3 Display device 4 Input Devices 10. Housing 11 Light projector 12 Receiving lens 13 Imaging unit 14 Light source 15 Projection lens 16 Floodlight 17 Light receiving window 18 Reflective material 20 Light emitting / receiving module 201 Base material 21 Motor 22 Control section 23 Motor control unit 24 Signal Processing Section 25 Communications Department 26 Peak detector 27 Profile Generation Unit 28 3D Data Generation Division 30 Fixed board 31 First flexible printed circuit board 311 Bend 312 Part 1 313 Part 2 32 Imaging board 33 First Guide 331, 332, 333 Rib structure 34 2nd Guide 35 Light projection board 36 Second flexible printed circuit board 100 Optical Displacement Measurement System AX1 light emitting axis AX2 optical axis I1 Image AX3 Rotation Axis R1 area W work

Claims

1. A light-projecting and light-receiving module including a light-projecting unit that projects slit light extending in the X direction onto a workpiece, a light-receiving lens that collects the light reflected from the workpiece, and an imaging unit that receives the light collected by the light-receiving lens; a motor for rotating the light emitting and receiving modules together; a housing for storing the light emitting / receiving module; A fixed substrate fixed to the housing; a first flexible printed circuit board connecting the light emitting and receiving module and the fixed substrate; The first flexible printed circuit board is an optical displacement meter having a bent portion over the entire first angle range of the measurement target of the light emitting and receiving module.

2. 2. The optical displacement meter according to claim 1, further comprising a guide structure for changing a position of the bent portion in the first flexible printed circuit board as the light projecting and receiving module rotates, and for keeping an amount of change in a radius of curvature of the bent portion due to rotation of the light projecting and receiving module over the entire first angle range within a predetermined range.

3. the guide structure includes a first guide fixed to the housing and a second guide rotated integrally with the light emitting and receiving module by the motor; 3. The optical displacement meter according to claim 2, wherein the first flexible printed circuit board has the bent portion between the first guide and the second guide over the entire first angle range when viewed along a rotation axis direction of the light emitting and receiving module.

4. the first flexible printed circuit board has a first portion guided along the first guide and a second portion guided along the second guide, 4. The optical displacement meter according to claim 3, wherein the bent portion forms a substantially U-shape from the first portion to the second portion when viewed along a direction of a rotation axis of the light emitting and receiving module.

5. the first guide has an arc shape when viewed from a direction of a rotation axis of the light emitting and receiving module, and has a first wall surface that guides the first portion; the second guide has a second wall surface that is arcuate when viewed from a direction of a rotation axis of the light emitting and receiving module and guides the second portion; 5. The optical displacement meter according to claim 4, wherein the first wall surface and the second wall surface are arranged in a substantially concentric arrangement with a rotation axis of the light emitting and receiving module as a center.

6. The optical displacement meter according to claim 5 , wherein a radius of curvature of the second wall surface is smaller than a radius of curvature of the first wall surface and larger than the radius of curvature of the bent portion of the first flexible printed circuit.

7. the first flexible printed circuit board electrically connects the imaging unit and the fixed substrate; the light emitting / receiving module further includes a second flexible printed circuit board electrically connecting the light emitting unit and the fixed substrate and having a bent portion over the entire first angle range; 3. The optical displacement meter according to claim 2, wherein the guide structure changes the position of the bent portion in the second flexible printed circuit board in accordance with rotation of the light emitting and receiving module, and limits the amount of change in the radius of curvature of the bent portion due to rotation of the light emitting and receiving module over the entire first angle range within a predetermined range.

8. 8. The optical displacement meter according to claim 7, wherein the first flexible printed circuit board and the second flexible printed circuit board are guided together by the guide structure while being aligned in a direction of a rotation axis of the light emitting and receiving module.

9. The optical displacement meter according to claim 8 , wherein the guide structure further includes a rib structure for preventing contact between the first flexible printed circuit board and the second flexible printed circuit board.

10. the light emitting / receiving module is configured to be rotatable by rotation of the motor to a second angle range that is outside the first angle range and is not a measurement target; The optical displacement meter according to claim 1 , wherein the first flexible printed circuit board has the bent portion over the entire second angle range.

11. 2. The optical displacement meter according to claim 1, wherein the first flexible printed circuit board has a spiral shape and is configured to be capable of at least one of twisting and expanding and contracting along a rotation axis of the light emitting and receiving module.

Images