Optical displacement measurement system

Abstract

To provide an optical displacement measurement system capable of making efficient a setting for allowing a user to select an appropriate measurement condition.SOLUTION: A control section of an optical displacement measurement system controls a light projection / reception module so as to relatively move the light projection / reception module and a work within each measurement range including at least a common range by a movement mechanism and successively acquire multiple light reception images of the work on the basis of each of multiple pieces of exposure time, acquires information on XYZ coordinates showing the shape of the work on the basis of multiple light reception images at each of the multiple pieces of exposure time, generates a work image showing the shape of the work on the basis of the information on XYZ coordinates, and generates a setting screen for displaying multiple work images corresponding to each of the multiple pieces of exposure time. A setting device is configured so as to be capable of receiving selection of one exposure time from among the multiple pieces of exposure time via the setting screen, and then receiving adjustment of an image processing parameter executed to multiple pieces of acquired light reception images on the basis of the selected exposure time.SELECTED DRAWING: Figure 9C

Description

[Technical Field]

[0001] The present invention relates to an optical displacement measurement system that detects the displacement of a measurement object by a triangulation method. [Background technology]

[0002] In a light-cutting type optical displacement measurement system, a band of light with a linear cross section is projected from the light projector onto the object to be measured (hereinafter referred to as the workpiece), and the reflected light is received by a two-dimensional light receiving element (image sensor).The workpiece profile (two-dimensional cross-sectional profile) is measured based on the peak position of the distribution of the amount of received light obtained by the light receiving element, and a workpiece image showing the shape of the workpiece is generated from the two-dimensional cross-sectional profile.

[0003] In conventional optical displacement measurement systems, the user adjusts the brightness (exposure time of the image sensor) while checking the received light amount information for each two-dimensional cross-sectional profile.

[0004] On the other hand, there is known a system that displays an image based on three-dimensional shape data measured under multiple measurement conditions, including exposure time, and allows the user to select the optimal measurement conditions while checking the image (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-055815 Summary of the Invention [Problem to be solved by the invention]

[0006] In conventional optical displacement measurement systems, if the user could adjust the brightness while checking the entire measurement range using a workpiece image rather than using received light intensity information in units of two-dimensional cross-sectional profiles, more appropriate adjustments could be expected.

[0007] However, in conventional optical displacement measurement systems, relative movement between the light-emitting / receiving module and the workpiece is required for the user to adjust the brightness while checking the overall measurement range using the workpiece image. Therefore, in optical displacement measurement systems, to change the exposure conditions and retake images, the same relative movement or the opposite relative movement must be reproduced under each of the multiple exposure conditions. In other words, the user must repeatedly change the exposure conditions and then perform the same relative movement for each exposure condition, and then separately compare the workpiece images taken under each exposure condition to determine which exposure condition to ultimately select. Therefore, in conventional optical displacement measurement systems, it takes a lot of time and effort for the user to select the appropriate exposure time.

[0008] In Patent Document 1, although the user can select the optimal measurement conditions from multiple measurement conditions including exposure time, there is no room for fine adjustment. For example, after first selecting an appropriate exposure time, there may be cases where the user wants to adjust the image processing parameters for the received light image obtained with that exposure time to enable more accurate measurement, but Patent Document 1 does not take this into consideration. Furthermore, Patent Document 1 does not take into consideration optimizing the control parameters of the movement mechanism.

[0009] An object of the present invention is to provide an optical displacement measurement system that allows the user to efficiently perform settings for selecting appropriate measurement conditions. [Means for solving the problem]

[0010] According to one aspect of the present invention, an optical displacement measurement system includes a light projecting / receiving module having a light projecting unit that projects slit light extending in an X direction onto a workpiece, an image sensor having a plurality of pixels two-dimensionally arranged in a U direction corresponding to the X direction and a V direction orthogonal to the U direction, the image sensor receiving light reflected by the workpiece by the plurality of pixels and outputting a received light image showing a distribution of received light amounts, a movement mechanism that moves the light projecting / receiving module and the workpiece relatively, a setting device that sets control conditions for the light projecting / receiving module and the movement mechanism, and a control unit that controls the light projecting / receiving module and the movement mechanism based on the control conditions. The control conditions include a plurality of different exposure times for the image sensor. The control unit controls the light emitting and receiving module to sequentially acquire multiple light receiving images of the workpiece based on each of the multiple exposure times while using the moving mechanism to move the light emitting and receiving module and the workpiece relatively within each measurement range including at least a common range, acquires XYZ coordinate information indicating the shape of the workpiece based on the multiple light receiving images at each of the multiple exposure times, generates a workpiece image indicating the shape of the workpiece based on the XYZ coordinate information, and generates a setting screen that displays the multiple workpiece images corresponding to each of the multiple exposure times, and the setting device is configured to accept selection of one exposure time from the multiple exposure times via the setting screen, and then accept adjustment of image processing parameters to be performed on the multiple light receiving images acquired based on the selected exposure time.

[0011] An optical displacement measurement system according to another aspect of the present invention includes a light projecting and receiving module having a light projecting unit that projects slit light extending in an X direction onto a workpiece, and an image sensor having a plurality of pixels that are two-dimensionally arranged in a U direction corresponding to the X direction and a V direction orthogonal to the U direction, the image sensor receiving the light reflected by the workpiece by the plurality of pixels and outputting a light reception image showing a distribution of the amount of received light, a moving mechanism that moves the light projecting and receiving module and the workpiece relatively, a setting device that sets control conditions for the light projecting and receiving module and the moving mechanism, and a control unit that controls the light projecting and receiving module and the moving mechanism based on the control conditions. The control conditions include a plurality of different exposure times of the image sensor, and the control unit controls the light emitting and receiving module to sequentially acquire a plurality of the light receiving images of the work based on each of the plurality of exposure times while moving the light emitting and receiving module and the work relatively within each measurement range including at least a common range using the moving mechanism, acquires XYZ coordinate information indicating the shape of the work based on the plurality of light receiving images at each of the plurality of exposure times, generates a work image indicating the shape of the work based on the XYZ coordinate information, and generates a setting screen displaying the plurality of work images corresponding to each of the plurality of exposure times, and the control conditions include the measurement range, drive control parameters including the moving speed of the moving mechanism, and the number of times the image sensor captures images within the measurement range, and the setting device determines the drive control parameters based on the measurement range, the number of times the image sensor captures images within the measurement range, and each of the plurality of exposure times.

[0012] Still other features, elements, steps, advantages, and characteristics will become more apparent from the detailed description that follows and the accompanying drawings related thereto. [Effects of the Invention]

[0013] The optical displacement measurement system according to the present invention can improve the efficiency of settings that allow a user to select appropriate measurement conditions. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram illustrating an optical displacement measurement system according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating a measurement range of a rotary optical displacement meter. [Figure 3] FIG. 10 is a diagram illustrating an optical displacement meter equipped with a reflecting member. [Figure 4] FIG. 10 is a diagram illustrating a method for detecting a peak position. [Figure 5] FIG. 2 is a functional block diagram of an optical displacement meter. [Figure 6] FIG. 10 is a diagram showing a processing flow for setting an exposure time of the optical displacement measurement system. [Figure 7] FIG. 10 is a diagram showing a process flow for setting parameters of a peak width filter of the optical displacement measurement system. [Figure 8] FIG. 10 is a diagram showing a processing flow for setting parameters for peak selection in the optical displacement measurement system. [Figure 9A] FIG. 1 is a diagram showing a GUI (graphical user interface). [Figure 9B] FIG. 10 is a diagram illustrating a GUI. [Figure 9C] FIG. 10 is a diagram illustrating a GUI. [Figure 9D] FIG. 10 is a diagram illustrating a GUI. [Figure 9E] FIG. 10 is a diagram illustrating a GUI. [Figure 9F] FIG. 10 is a diagram illustrating a GUI. [Figure 9G] FIG. 10 is a diagram illustrating a GUI. [Figure 9H] FIG. 10 is a diagram illustrating a GUI. [Figure 10] 10 is a flowchart showing a procedure for determining a control parameter of a motor. [Figure 11] FIG. 10 is a diagram illustrating an optical displacement measurement system according to a second embodiment. [Figure 12] FIG. 1 is a diagram illustrating the principle of triangulation. [Figure 13] FIG. 10 is a diagram illustrating a method for detecting a peak position. [Figure 14] FIG. 2 is a functional block diagram of an optical displacement meter. [Figure 15] FIG. 10 is a diagram showing a modified example of the optical displacement meter. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the present invention, its applications, or its uses.

[0016] <<First Embodiment>> <Optical displacement measurement system> Fig. 1 is a diagram showing a schematic configuration example of an optical displacement measurement system according to the first embodiment. The optical displacement measurement system 100 shown in Fig. 1 includes an optical displacement meter 1, a control device 2, a display device 3, and an input device 4.

[0017] In this embodiment, 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 projecting unit (not shown in FIG. 1). The XZ plane, which will be described later, is a plane extending in the X and Z directions. Note that the optical displacement meter 1 scans the slit light L1 by rotating the light projecting and receiving module 20 (see FIG. 5, which will be described later), so the scanning direction of the slit light L1 is a direction perpendicular to the X direction in the YZ plane, including the Y direction. Note that in this specification, "rotation" means a swinging motion that reciprocates around a rotation axis.

[0018] 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 that indicates 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 that indicates the outer edge of the cut surface that is parallel to the XZ plane, and therefore is also referred to as a two-dimensional profile of the XZ cross section of the workpiece W.

[0019] 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. Note that a three-dimensional shape is a collection of (xi, yi, zi). yi indicates the position in the Y direction.

[0020] 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 results. The optical displacement meter 1 performs imaging at regular intervals to generate profiles of the workpiece W with different yi. The optical displacement meter 1 also generates three-dimensional shape data of the workpiece W from the profiles of the workpiece W with different yi.

[0021] 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. The control device 2 is also a setting device for setting control conditions for a movement mechanism (a movement mechanism that moves the light emitting and receiving module 20 and the workpiece W relatively) including the light emitting and receiving module 20 and a motor 21 (see FIG. 5 described later). When the input device 4 is operated by a user, the control device 2 detects the operation and accepts settings of control conditions for the movement mechanism including the light emitting and receiving module 20 and the motor 21. The control device 2 includes a memory unit, and the memory unit stores a program (hereinafter referred to as an "imaging navigation program") for setting control conditions for the movement mechanism including the light emitting and receiving module 20 and the motor 21, default settings of the control conditions for the light emitting and receiving module 20 and the motor 21, XYZ coordinate information indicating the shape of the workpiece W, etc.

[0022] 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.

[0023] The input device 4 accepts 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 disposed on the display screen of the display device 3.

[0024] 2 is a diagram illustrating the measurement range of the rotary optical displacement meter 1. A light projecting unit 11, a light receiving lens 12, and an imaging unit 13 are housed inside a housing 10 of the optical displacement meter 1. The light projecting unit 11 has a light source 14 and a projection lens 15. For example, the light source 14 may be a laser beam emitter, and the projection lens 15 may be composed of multiple lenses including a cylindrical lens.

[0025] Light output from the light source 14 passes through a light projecting lens 15 and is converted into slit light L1. The housing 10 is provided with a light projecting window 16 that has light transmissibility that allows the slit light L1 to pass through. Similarly, the housing 10 is provided with a light receiving window 17 that has light transmissibility that allows the reflected light L2 to pass through. The light projecting window 16 and the light receiving window 17 are separate bodies (separate components). Because the light projecting window 16 and the light receiving window 17 are separate bodies, the light projecting window 16 and the light receiving window 17 are each flat-shaped components, which makes it easy to manufacture the light projecting window 16 and the light receiving window 17. However, the light projecting window 16 and the light receiving window 17 may be integrated (one component).

[0026] The light-receiving lens 12 is a lens that collects the reflected light L2 and forms an image on the light-receiving surface of the imaging unit 13. The light-receiving lens 12 may include only one lens, or may include multiple lenses. The light-receiving lens 12 may also include optical components other than lenses (for example, optical filters). The imaging unit 13 is an image sensor that has multiple photoelectric conversion elements that are two-dimensionally arranged. The imaging unit 13 receives the light collected by the light-receiving lens.

[0027] As shown in FIG. 2, the optical axis AX2 of the light-receiving lens 12 is inclined with respect to the light projection axis AX1 of the light-projecting unit 11. The light 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 height Z1 forms an image at position V1 in the V direction on the light-receiving surface of the imaging unit 13, and the reflected light L2 from height Z2 forms an image at position V2 in the V direction on the light-receiving surface of the imaging unit 13. In other words, 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. In other words, the vertical direction of the light-receiving image showing the distribution of the amount of received light output by the imaging unit 13 is the V direction, and the horizontal direction is the U direction.

[0028] Light projecting unit 11, light receiving lens 12, and imaging unit 13 are rotatable around 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 shown by solid lines, and the states after rotation in the counterclockwise direction CCW are shown by dashed lines.

[0029] Limiting the rotation range of motor 21 (see FIG. 5 described later) also limits the rotation range of light projecting unit 11, light receiving lens 12, and imaging unit 13. The rotation range of motor 21 may be limited, for example, by controlling motor 21, or by a stopper that physically stops the movement of light projecting and receiving module 20 (see FIG. 5 described later).

[0030] At one end of the rotation range of the motor 21, the light-receiving window 17 and the end of the light-receiving unit 18, which has the light-receiving lens 12 and the imaging unit 13, on the workpiece W side are close to each other while being separated from each other, and the inner wall of the housing 10 and the light-projecting unit 11 are separated from each other. At the other end of the rotation range of the motor 21, the light-projecting window 16 and the end of the light-projecting unit 11 on the workpiece W side are close to each other while being separated from each other, and the inner wall of the housing 10 and the light-receiving unit 18 are separated from each other. This makes it possible to reduce the size of the housing 10 while avoiding contact between the light-receiving window 17 and the light-receiving unit 18 and between the light-projecting window 16 and the light-projecting unit 11.

[0031] The light projecting unit 11, the light receiving lens 12, and the image capturing 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 image capturing unit 13 is inclined relative 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 region 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. Therefore, the region R1 should be set as the measurement range of the slit light L1. In other words, the measurement range of the slit light L1 should be formed within a range in which the Scheimpflug relationship holds for each rotation angle of the motor 21 (see FIG. 5, described later).

[0032] The positional relationship between light projecting unit 11, light receiving lens 12, and imaging unit 13 may be reversed from that shown in FIG.

[0033] 3, the optical displacement meter 1 may further include a reflecting member 19. When the optical displacement meter 1 includes the reflecting member 19, the light-receiving unit 18 includes the light-receiving lens 12, the imaging unit 13, and the reflecting member 19. The reflecting member 19 is provided on the optical path between the light-receiving window 17 and the imaging unit 13, and bends the reflected light L2 and the optical axis AX2 of the light-receiving lens 12 back toward the light-projecting unit 11. This allows the light-projecting and receiving module, which integrally holds the light-projecting unit 11, the light-receiving lens 12, the imaging unit 13, and the reflecting member 19, to be compact 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, which integrally holds the light-projecting unit 11, the light-receiving lens 12, the imaging unit 13, and the reflecting member 19, to be reduced.

[0034] In FIG. 3, the reflecting member 19 is provided on the optical path between the light receiving lens 12 and the imaging unit 13, but it may also be provided on the optical path between the light receiving window 17 and the light receiving lens 12.

[0035] When the reflecting member 19 is provided on the optical path between the light-receiving lens 12 and the imaging unit 13, the reflecting member 19 reflects the light after it has been collected by the light-receiving lens 12, thereby making it possible to reduce the area of ​​the reflective surface of the reflecting member 19. When the reflecting member 19 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 positioned closer to the rotation axis AX3, thereby significantly reducing the moment of inertia.

[0036] <Position (height calculation)> 4 is a diagram illustrating 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 that reflected light L2 brings to the light receiving surface of image capture unit 13 also becomes wide enough to span multiple photoelectric conversion elements.

[0037] Therefore, the optical displacement meter 1 obtains an approximate curve P1 indicating the change in brightness value from the brightness value of each pixel, and calculates the position in the V direction where the approximate curve P1 produces a peak value. In Figure 4, the leftmost column is the column of interest, and an example of the distribution of brightness values ​​(approximate curve P1) for the column of interest is shown. The approximate curve P1 is obtained by curve fitting multiple sample values, for example. Sample values ​​below the detection threshold are not taken into account. The position in the V direction where this peak value produces indicates the height of the workpiece W. The optical displacement meter 1 obtains an approximate curve P1 at each position (each pixel column) in the U direction, and calculates the position (height) in the V direction where the peak value produces from the approximate curve P1. By performing this calculation process at each position in the U direction, a single profile can be obtained. This type of calculation process may be referred to as subpixel processing.

[0038] Note that, for example, a coordinate conversion condition (e.g., a coordinate conversion table) indicating the correspondence between UV coordinates and the rotation angle θ, such as (U, V, θ) = (X, Y, Z), and the local coordinates (X, Y, Z), is generated by pre-shipment calibration 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. Note that, in the coordinate conversion, equal-interval correction may be performed in the X and Y directions so that positions in the X and Y directions are plotted at equal intervals, and Z corresponding to the corrected (X, Y) may be calculated by linear interpolation or the like and output as the measurement result. Image processing performed on the measurement results often assumes data sampled at equal intervals in the X and Y directions, so equal-interval correction facilitates subsequent image processing.

[0039] <Function block> 5 is a functional block diagram of the optical displacement meter 1. The optical displacement meter 1 includes a light emitting / receiving module 20, a motor 21, and a control unit 22.

[0040] The light-emitting and light-receiving module 20 integrally holds the light-emitting unit 11, the light-receiving lens 12, and the imaging unit 13. Furthermore, if the optical displacement meter 1 includes a reflecting member 19, the light-emitting and light-receiving module 20 integrally holds the light-emitting unit 11, the light-receiving lens 12, the imaging unit 13, and the reflecting member 19 (not shown in FIG. 5).

[0041] 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.

[0042] Control unit 22 includes motor control unit 23, signal processing unit 24, and communication unit 25. Control unit 22 controls motor 21 to rotate light projector 11, light-receiving lens 12, and image capture unit 13 in a state where the Scheimpflug relationship is satisfied, thereby scanning slit light L1 in a direction intersecting the X direction. More specifically, motor control unit 23 controls motor 21 to rotate light projector 11, light-receiving lens 12, and image capture unit 13 in a state where the Scheimpflug relationship is satisfied, and signal processing unit 24 controls light projector 11 to irradiate slit light L1 from light projector 11.

[0043] The signal processing unit 24 includes a peak detection unit 241 , a profile generation unit 242 , a three-dimensional data generation unit 243 , and an inspection unit 244 .

[0044] The peak detection unit 241 detects the position in the V direction (peak position) that brings about the peak of the brightness value based on the light reception result output from the imaging unit 13. The profile generation unit 242 generates one profile data by summarizing the height (zi) of the workpiece W at each position (xi) in the X direction determined by the peak detection unit 241. The three-dimensional data generation unit 243 generates three-dimensional shape data of the workpiece W from the profiles of the workpiece W with different yi generated by the profile generation unit 242.

[0045] The inspection unit 244 inspects the workpiece W based on the three-dimensional shape data of the workpiece W generated by the three-dimensional data generation unit 243. The inspection unit 244 performs predetermined measurements on the three-dimensional shape data of the workpiece W, and inspects the workpiece W based on the measurement results. For example, the inspection unit 244 measures the length, angle, etc. of a predetermined portion of the workpiece W. Then, the inspection unit 244 determines whether the workpiece W is a non-defective product based on these measurement results and preset thresholds, etc.

[0046] At least a part of the peak detection unit 241, the profile generation unit 242, the three-dimensional data generation unit 243, and the inspection unit 244 may be provided in a location (for example, inside the control device 2 shown in FIG. 1) separate from the main body of the optical displacement meter 1. In this case, the optical displacement meter 1 has a separate structure consisting of the main body of the optical displacement meter 1 and a separate part of the optical displacement meter 1.

[0047] The communication unit 25 communicates with the control device 2 via wired or wireless communication. 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, and inspection results of the workpiece W determined by the inspection unit 244, to the control device 2.

[0048] <Processing flow> Fig. 6 is a diagram showing a processing flow for setting the exposure time of the optical displacement measurement system 100. Fig. 7 is a diagram showing a processing flow for setting parameters of a peak width filter of the optical displacement measurement system 100. Fig. 8 is a diagram showing a processing flow for setting parameters of peak selection of the optical displacement measurement system 100. The peak width filter is a function for deleting peak candidate positions in the V direction with wide peak widths. Peak selection is a function for selecting a peak position in the V direction from peak candidate positions in the V direction. The peak width filter parameters and peak selection parameters are each an example of peak detection parameters.

[0049] 9A to 9H are diagrams showing GUIs corresponding to the processing flows shown in Fig. 6 to Fig. 8. When the imaging navigation program is executed by the control device 2, a GUI 300 is displayed on the display device 3. The GUI 300 (= various setting screens 300a to 300h) corresponding to the processing flows shown in Fig. 6 to Fig. 8 includes, as its basic layout, an image display area 310, an operation area 320, and a progress display area 330.

[0050] The image display area 310 displays a distance image (2D image) showing the height of the workpiece W in the Z direction on the XY plane, or a three-dimensional image (3D image) showing the three-dimensional shape of the workpiece. The distance image (2D image) is a color image in which a color corresponding to the height of the workpiece W in the Z direction on the XY plane is displayed. Note that the distance image is not limited to a color image, but may be a grayscale image in which a brightness value corresponding to the height is displayed. The image display area 310 also includes an image type display banner 311, an enlarge button 312, a reduce button 313, an angle change button 314, and a maximize button 315. The image type display banner 311 clearly displays whether a 2D image or a 3D image is being displayed. The enlarge button 312, the reduce button 313, the angle change button 314, and the maximize button 315 are operated to enlarge, reduce, change the angle, and maximize the image displayed in the image display area 310, respectively.

[0051] Displayed in operation area 320 are an exposure time active setting field 321A, a peak width filter active setting field 321B, a peak selection active setting field 321C, a 2D display switch button 322A, a 3D display switch button 322B, an image update button 323, a back button 324A, a next button 324B, a done button 325A, and a cancel button 325B. In exposure time active setting field 321A, peak width filter active setting field 321B, and peak selection active setting field 321C, it is possible to select from candidate parameters (parameters stored in the memory unit of control device 2) using pull-down menus.

[0052] In the process flow shown in FIG. 6, the first step (setting the exposure time) is executed, in the process flow shown in FIG. 7, the second step (setting the peak width filter) is executed, and in the process flow shown in FIG. 8, the third step (setting the peak selection) is executed. In the progress display area 330, each step is displayed in a flow diagram, and the step currently being executed is highlighted. This configuration allows the user to grasp the progress of the setting work at a glance. Note that the present invention does not necessarily have to include three steps. Furthermore, the content executed in each step is not limited to those described above. For example, measurement conditions such as the output intensity of the light source 14 and detection sensitivity (threshold value of the amount of received light detected as a peak) may be selected optimally by displaying workpiece images based on different output intensities and detection sensitivities.

[0053] In the optical displacement measurement system 100, after the user selects an appropriate exposure time in the first step, any configuration is sufficient as long as it allows for adjustment of image processing parameters to be performed on multiple received light images acquired based on the selected exposure time to enable more accurate measurements. The configuration is not limited to a flow diagram, such as the progress display area 330, where each step is displayed. After reviewing the workpiece images acquired based on the selected exposure time, the user can adjust the image processing parameters if necessary, or complete the settings if no adjustment is necessary, allowing for flexible settings. Note that the image processing parameters may include the peak detection parameters described above, as well as various filters such as dilation, erosion, and averaging, contrast conversion, and interpolation using pixel values ​​around unmeasurable pixels.

[0054] The imaging navigation program is started when the optical displacement measurement system 100 is started for the first time. The imaging navigation program is also started when the input device 4 receives a user input instructing the start of the imaging navigation program. When the imaging navigation program is started, the processing flow of Fig. 6 starts.

[0055] First, in step S1, the control device 2 acquires default values ​​for the exposure time from the storage unit. There may be multiple default values ​​for the exposure time, but the following description will be given as an example in which there are four default values ​​for the exposure time: T1, T2, T3, and T4.

[0056] In the subsequent step S2, the control device 2 acquires other control conditions from the storage unit. Examples of the other control conditions include drive control parameters of the motor 21 (such as the rotation speed of the light-emitting and receiving module 20, the rotation angle range of the light-emitting and receiving module 20, and the acceleration and deceleration time of the light-emitting and receiving module 20), and imaging-related parameters other than the exposure time (such as the output intensity of the light-emitting unit 11, the detection sensitivity of the imaging unit 13, HDR [High Dynamic Range] parameters, initial parameters of the peak width filter, initial parameters of peak selection, and imaging period). The procedure for determining the drive control parameters of the motor 21 will be described later. After completing the processes of steps S1 and S2, the control device 2 displays a setting screen 300a shown in FIG. 9A on the display device 3. In the example shown in FIG. 9A, the initial parameter of the peak width filter is F1, and the initial parameter of peak selection is SEL1.

[0057] In the following step S3, the control unit 22 moves the light emitting / receiving module 20 to the scan start position. Also in step S3, the light projecting unit 11 starts emitting the slit light L1. When the processing of step S3 ends, the flow proceeds to step S4.

[0058] The imaging unit 13 captures images at an imaging period, for example, at equal time intervals or equal rotation intervals of the motor 21 (step S4), and generates a received light image in which the vertical direction is the V direction and the horizontal direction is the U direction (step S5). When capturing images at equal rotation intervals, position information of the rotation of the motor 21 can be detected by, for example, an encoder.

[0059] In the following step S6, the peak detection unit 241 detects up to N (N is a predetermined integer equal to or greater than 2) V-direction peak candidate positions that are equal to or greater than a predetermined luminance value (amount of received light) at each position in the U-direction of the received light image based on the initial parameter F1 of the peak width filter. If there are more than N V-direction peak candidate positions, the N positions are detected in descending order of luminance value (amount of received light). Note that it is possible that the number of detected V-direction peak candidate positions is zero.

[0060] The above-described processing of steps S4 to S6 is executed for each photographing cycle in which one received-light image is photographed.

[0061] Then, when the irradiation position of the slit light L1 reaches the scanning end position, the control unit 22 ends the movement of the light emitting and receiving module 20, and ends the relative movement between the workpiece W and the light emitting and receiving module 20 (step S7). Also, in step S7, the light projecting unit 11 ends the irradiation of the slit light L1. When the processing of step S7 ends, the flow proceeds to step S8.

[0062] In step S8, the peak detection unit 241 selects a peak position in the V direction from peak candidate positions in the V direction at each position in the U direction of the received light image based on the initial parameter SEL1 for peak selection. When the processing of step S8 ends, the flow proceeds to step S9.

[0063] The profile generation unit 242 converts the profile in the UV coordinate system at each position of the rotation angle θ of the light emitting and receiving module 20 into the XYZ coordinate system (step S9), and generates a two-dimensional profile of the XZ cross section of the workpiece W at each position in the Y direction (step S10). The two-dimensional profile of the XZ cross section of the workpiece W at each position in the Y direction is XYZ coordinate information that indicates the shape of the workpiece W. When the processing of step S10 is completed, the flow proceeds to step S11.

[0064] In step S11, the control device 2 determines whether 2D display has been instructed based on the user input received by the input device 4. If 2D display has been instructed (YES in step S11), the display device 3 displays a 2D image generated based on XYZ coordinate information indicating the shape of the workpiece W (step S12). On the other hand, if 2D display has not been instructed (NO in step S11), the display device 3 displays a 3D image generated based on XYZ coordinate information indicating the shape of the workpiece W (step S13). The user may instruct 2D display, for example, when checking for unmeasured areas (invalid pixels) or observing in pixel units, or may instruct 3D display when, for example, intuitively checking the shape or checking for the presence or absence of points of different heights (noise). The following description will be given of an example where 2D display has not been instructed.

[0065] The processing of steps S3 to S13 described above is executed for each exposure time. Therefore, when the processing of steps S3 to S13 for exposure time T1 is completed, the control device 2 causes the display device 3 to display a setting screen 300b shown in Fig. 9B. When the processing of steps S3 to S13 for exposure times T1, T2, T3, and T4 is completed, the control device 2 causes the display device 3 to display a setting screen 300c shown in Fig. 9C.

[0066] The scanning start position in step S3 may be the same for all of exposure times T1, T2, T3, and T4, or the scanning end position for exposure time T1 may be the scanning start position for exposure time T2, the scanning end position for exposure time T2 may be the scanning start position for exposure time T3, and the scanning end position for exposure time T3 may be the scanning start position for exposure time T4. In the latter case, there is a risk of positional deviation between the scanning end position and the next scanning start position, but this positional deviation is slight, and each measurement range for each exposure time includes a common range.

[0067] Since the display of 2D or 3D images acquired for different exposure times is automated, the effort and time required for the user to select an appropriate exposure time can be reduced.

[0068] Note that the processing of steps S3 to S13 for exposure time t2 may be started after the processing of steps S3 to S13 for exposure time t1 is completed, or step S3 for exposure time T2 may be started after step S7 for exposure time T1 is completed and before the processing of step S13 is completed. The latter, so-called parallel processing, can speed up the setting processing.

[0069] In the setting screen 300c shown in FIG. 9C, the exposure time T1 is set as the active setting, and the enlarge button 312, reduce button 313, angle change button 314, maximum display button 315, 2D display switch button 322A, and 3D display switch button 322B are enabled for the 3D image at the exposure time T1.

[0070] When the 3D image at exposure time T1 is enlarged by clicking the enlarge button 312, the 3D images at exposure times T2, T3, and T4 are also enlarged under the same display conditions as the 3D image at exposure time T1, and the setting screen 300c shown in Figure 9C transitions to the setting screen 300d shown in Figure 9D.

[0071] The same applies to the zoom out button 313, angle change button 314, 2D display switch button 322A, and 3D display switch button 322B; when various processes are instructed for one image that corresponds to the active setting, the same processes are also applied to the remaining images that do not correspond to the active setting.

[0072] Furthermore, on the setting screen 300c shown in FIG. 9C, clicking on the maximum display button 315 associated with the 3D image at the exposure time T1 causes the screen to transition to a setting screen 300e shown in FIG. 9E.

[0073] In the setting screen 300e shown in FIG. 9E, a minimize button 316, a forward button 317, and a reverse button 318 are displayed in the image display area 310. Clicking the minimize button 316 transitions the setting screen 300e shown in FIG. 9E to the setting screen 300c shown in FIG. 9C. Clicking the forward button 317 on the setting screen 300e shown in FIG. 9E switches from the 3D image with the exposure time T1 displayed at its maximum to the 3D image with the exposure time T2 displayed at its maximum, and the 3D image with the exposure time T2 displayed at its maximum becomes the image corresponding to the active setting. Clicking the reverse button 318 on the setting screen 300e shown in FIG. 9E switches from the 3D image with the exposure time T1 displayed at its maximum to the 3D image with the exposure time T4 displayed at its maximum, and the 3D image with the exposure time T4 displayed at its maximum becomes the image corresponding to the active setting.

[0074] In the setting screen 300e shown in FIG. 9E, when the zoom in button 312, zoom out button 313, angle change button 314, 2D display switch button 322A, or 3D display switch button 322B is clicked to instruct various processes for one image corresponding to the active setting, the same processes are also applied to the remaining images (not displayed on the setting screen 300e) that do not correspond to the active setting.

[0075] When the processing of steps S3 to S13 described above for each exposure time is completed, the flow proceeds to step S14.

[0076] In step S14, the control device 2 determines whether or not there is an input to change the exposure time, based on the user input received by the input device 4. Note that the input to change the exposure time may be received before step S3.

[0077] For example, when T5 is input into the exposure time active setting field 321A on the setting screen 300c shown in Fig. 9C, the control device 3 determines that there is an input to change the exposure time (YES in step S14), changes the exposure time T1 to exposure time T5, and displays the setting screen 300f shown in Fig. 9F on the display device 2. Then, the control device 2 causes the optical displacement meter 1 to perform only imaging for the changed exposure time T5 (step S16).

[0078] If the control device 2 determines that there is no input to change the exposure time (NO in step S14) or if the processing of step S16 is completed, the flow proceeds to step S17.

[0079] In step S17, the control device 2 determines whether or not an image update instruction has been issued based on whether or not the image update button 323 has been clicked. If the control device 2 determines that an image update instruction has been issued (YES in step S17), the process returns to step S3. On the other hand, if the control device 2 determines that an image update instruction has not been issued (NO in step S17), the process proceeds to step S18.

[0080] In step S18, the control device 2 determines whether or not a command to set a peak width filter has been issued based on whether or not the next button 324B has been clicked.

[0081] When the Next button 324B is clicked, it is determined that there is an instruction to set a peak width filter (YES in step S18), and the process proceeds to the processing flow of FIG.

[0082] When the complete button 325A is clicked, it is determined that there is no instruction to set a peak width filter (NO in step S18), and the active setting of the exposure time is confirmed as a parameter of the exposure time, and the setting is terminated.When the cancel button 325B is clicked, it is determined that there is no instruction to set a peak width filter (NO in step S18), and the setting is terminated without confirming the active setting of the exposure time as a parameter of the exposure time.

[0083] 7, the control device 2 acquires the default values ​​of the peak width filter from the storage unit. There may be multiple default values ​​of the peak width filter, but the following description will be given as an example in which the default values ​​of the peak width filter are four, F1, F2, F3, and F4.

[0084] In the next step S102, the control device 2 reads out from the storage unit a plurality of received light images corresponding to the exposure time (here, T1) set in the processing flow of Fig. 6 or peak candidate information acquired from the plurality of received light images. The peak candidate information is information including the position and peak width of each peak candidate. Since storing all received light images would strain the capacity of the storage unit, it is sufficient to store only the information necessary to execute the peak detection process.

[0085] In the next step S103, the control device 2 performs peak width filtering on the plurality of received light images corresponding to the exposure time set in the processing flow of Fig. 6 or on peak candidate information acquired from the plurality of received light images. Note that in steps S102 and S103, it is also possible to perform peak width filtering on the newly acquired received light images after performing imaging again as in steps S3 to S6 based on the parameters of the determined exposure time.

[0086] In the following step S104, the control device 2 determines whether or not 2D display has been instructed based on the user input received by the input device 4. If 2D display has been instructed (YES in step S104), the display device 3 displays a 2D image generated based on XYZ coordinate information indicating the shape of the workpiece W (step S105). On the other hand, if 2D display has not been instructed (NO in step S105), the display device 3 displays a 3D image generated based on XYZ coordinate information indicating the shape of the workpiece W (step S106).

[0087] The processes of steps S103 to S106 described above are executed for each parameter of the peak width filter. Therefore, when the processes of steps S103 to S106 for the default values ​​F1, F2, F3, and F4 of the peak width filter are completed, the control device 2 causes the display device 3 to display a setting screen 300g shown in FIG. 9G.

[0088] When the processing of steps S103 to S106 described above for each parameter of the peak width filter is completed, the flow proceeds to step S107.

[0089] In step S107, the control device 2 determines whether or not there is an input to change the parameters of the peak width filter, based on the user input received by the input device 4. Note that the input to change the parameters of the peak width filter may be received before step S103.

[0090] For example, when F5 is entered in the active setting field 321B of the peak width filter on the setting screen 300g shown in FIG. 9G, the control device 2 determines that there is an input to change the peak width filter parameter (YES in step S107), and changes the peak width filter parameter F1 to the peak width filter parameter F5 (step S108).

[0091] If the control device 2 determines that there is no input to change the parameters of the peak width filter (NO in step S107) or if the processing of step S108 ends, the flow proceeds to step S109.

[0092] In step S109, the control device 2 determines whether or not an image update instruction has been issued based on whether or not the image update button 323 has been clicked. If the control device 2 determines that an image update instruction has been issued (YES in step S109), the process returns to step S103. On the other hand, if the control device 2 determines that an image update instruction has not been issued (NO in step S109), the process proceeds to step S110.

[0093] In step S110, the control device 2 determines whether or not there is an instruction to return to setting the exposure time based on whether or not the back button 324A has been clicked.

[0094] When the back button 324A is clicked, it is determined that there is an instruction to return to the exposure time setting (YES in step S110), and the process returns to the processing flow of FIG.

[0095] If the back button 324A is not clicked, it is determined that there is no instruction to return to the exposure time setting (NO in step S110), and the process proceeds to step S111.

[0096] In step S111, the control device 2 determines whether or not a peak selection setting instruction has been issued based on whether or not the next button 324B has been clicked.

[0097] When the Next button 324B is clicked, it is determined that there is an instruction to set a peak selection (YES in step S111), and the process proceeds to the processing flow of FIG.

[0098] When the complete button 325A is clicked, it is determined that there is no instruction to set a peak selection (NO in step S111), and the active setting of the peak width filter is confirmed as a parameter of the peak width filter, and the setting is completed.When the cancel button 325B is clicked, it is determined that there is no instruction to set a peak selection (NO in step S111), and the setting is completed without confirming the active setting of the peak width filter as a parameter of the peak width filter.

[0099] 8, the control device 2 acquires default values ​​for peak selection from the storage unit. There may be multiple default values ​​for peak selection, but the following description will be given as an example in which there are four default values ​​for peak selection: SEL1, SEL2, SEL3, and SEL4.

[0100] In the next step S202, the control device 2 reads out from the storage unit a plurality of received light images corresponding to the exposure time (here, T1) set in the processing flow of FIG. 6 or peak candidate information acquired from the plurality of received light images.

[0101] In the next step S203, the control device 2 performs peak width filtering set in the processing flow of Fig. 7 on the plurality of received light images corresponding to the exposure time set in the processing flow of Fig. 6 or on peak candidate information acquired from the plurality of received light images, and then performs peak selection. Note that in steps S102 and S103, imaging may be performed again as in steps S3 to S6 based on the parameters of the determined exposure time, and then peak width filtering and peak selection processing may be performed on the newly obtained received light images.

[0102] In the following step S204, the control device 2 determines whether or not 2D display has been instructed based on the user input received by the input device 4. If 2D display has been instructed (YES in step S204), the display device 3 displays a 2D image generated based on XYZ coordinate information indicating the shape of the workpiece W (step S205). On the other hand, if 2D display has not been instructed (NO in step S205), the display device 3 displays a 3D image generated based on XYZ coordinate information indicating the shape of the workpiece W (step S206).

[0103] The above-described processing of steps S203 to S206 is executed for each peak selection parameter. Therefore, when the processing of steps S203 to S206 for the peak selection default values ​​SEL1, SEL2, SEL3, and SEL4 is completed, the control device 2 causes the display device 3 to display a setting screen 300h shown in FIG. 9H.

[0104] When the processing of steps S203 to S206 described above for each parameter of peak selection is completed, the flow proceeds to step S207.

[0105] In step S207, the control device 2 determines whether or not there is an input to change the peak selection parameters, based on the user input received by the input device 4. Note that the input to change the peak selection parameters may be received before step S203.

[0106] For example, on the setting screen 300h shown in FIG. 9H, when SEL5 is entered in the peak selection active setting field 321B, the control device 2 determines that there is an input to change the peak selection parameter (YES in step S207), and changes the peak selection parameter SEL3 to the peak selection parameter SEL5 (step S208).

[0107] If the control device 2 determines that no input has been made to change the peak selection parameters (NO in step S207) or if the processing of step S208 has ended, the flow proceeds to step S209.

[0108] In step S209, the control device 2 determines whether or not an image update instruction has been issued based on whether or not the image update button 323 has been clicked. If the control device 2 determines that an image update instruction has been issued (YES in step S209), the process returns to step S203. On the other hand, if the control device 2 determines that an image update instruction has not been issued (NO in step S209), the process proceeds to step S210.

[0109] In step S120, the control device 2 determines whether or not there is an instruction to return to the setting of the peak width filter, based on whether or not the back button 324A has been clicked.

[0110] When the back button 324A is clicked, it is determined that there is an instruction to return to the peak width filter setting (YES in step S210), and the process returns to the processing flow of FIG.

[0111] If the back button 324A is not clicked, it is determined that there is no instruction to return to the peak width filter settings (NO in step S210), and if the complete button 325A is clicked, the active peak selection settings are confirmed as peak selection parameters and the settings are completed, and if the cancel button 325B is clicked, the active peak selection settings are not confirmed as peak selection parameters and the settings are completed.

[0112] FIG. 10 is a flowchart showing a procedure for determining the drive control parameters of the motor 21.

[0113] In step S301, the control device 2 inputs the measurement range (defined by the rotation range of the light emitting and receiving module 20 in this embodiment, and defined by the Y-direction movement range of the workpiece W in the second embodiment described later) and the number of times of imaging based on the user input received by the input device 4. Note that instead of the measurement range or the number of times of imaging, the imaging frequency (one image taken per predetermined range) may be input.

[0114] In the next step S302, the control device 2 determines the time for measuring one two-dimensional cross-sectional profile. The time for measuring one two-dimensional cross-sectional profile is determined according to the exposure time or the readout time of the imaging unit 13, whichever is longer.

[0115] In the following step S303, the control device 2 determines the time for the slit light L1 to pass through the measurement range (the scanning time required to scan the measurement range) based on the number of imaging times received in step S301 and the time for measuring one two-dimensional cross-sectional profile determined in step S302.

[0116] In the following step S304, the control device 2 determines the movement speed (defined by the rotation speed of the light emitting / receiving module 20 in this embodiment, and the Y-direction movement speed of the workpiece W in the second embodiment described later) based on the measurement range received in step S301 and the scanning time determined in step S303.

[0117] Finally, in step S305, the control device 2 determines the acceleration start position and acceleration so that the movement speed determined in step S304 is reached at the measurement start position, and determines the deceleration so that the movement speed determined in step S304 at the measurement end position is stopped at a predetermined position. This makes it possible to set drive control parameters that are optimal for the user's measurement conditions, thereby reducing the time required for setting, for example.

[0118] The parameters received and determined in the flowchart of FIG. 10 are stored in the storage unit of the control device 2.

[0119] <<Second embodiment>> <Optical displacement measurement system> Fig. 11 is a diagram showing a schematic configuration example of an optical displacement measurement system according to the second embodiment. The optical displacement measurement system 100 shown in Fig. 11 includes an optical displacement meter 1, a control device 2, a display device 3, an input device 4, and a belt conveyor 5.

[0120] In this embodiment, 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 is a direction perpendicular to the X and Z directions. An XZ plane, which will be described later, is a plane extending in the X and Z directions.

[0121] The optical displacement measurement system 100 is a system that measures the profile and three-dimensional shape of a workpiece W that is transported in the Y direction by a belt conveyor 5. The profile of the workpiece W is data that indicates the outer edge of the cut surface of the workpiece W by a slit light L1. When the slit light is irradiated parallel to the XZ plane, the profile of the workpiece W becomes data that indicates the outer edge of the cut surface that is parallel to the XZ plane, and is therefore also referred to as a two-dimensional profile of the XZ cross section of the workpiece W.

[0122] 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. Note that a three-dimensional shape is a collection of (xi, yi, zi). yi indicates the position in the Y direction.

[0123] 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 results. The optical displacement meter 1 performs imaging at regular intervals to generate profiles of the workpiece W with different yi. The optical displacement meter 1 also generates three-dimensional shape data of the workpiece W from the profiles of the workpiece W with different yi.

[0124] 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. The control device 2 is also a setting device for setting control conditions for the light emitting and receiving module 20 (see FIG. 14 described later) and the belt conveyor 5 (a movement mechanism that moves the light emitting and receiving module 20 and the workpiece W relative to each other). When the input device 4 is operated by a user, the control device 2 detects the operation and accepts settings of control conditions for the light emitting and receiving module 20 and the drive motor of the belt conveyor 5. The control device 2 includes a memory unit, and the memory unit stores a program (image capture navigation program) for setting control conditions for the light emitting and receiving module 20 and the belt conveyor 5, default settings of control conditions for the light emitting and receiving module 20 and the belt conveyor 5, XYZ coordinate information indicating the shape of the workpiece W, etc.

[0125] 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.

[0126] The input device 4 accepts 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 disposed on the display screen of the display device 3.

[0127] FIG. 12 is a diagram illustrating the principle of the light-section method (triangulation). A light-projecting unit 11, a light-receiving lens 12, and an imaging unit 13 are built into 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 multiple lenses including a cylindrical lens. The light output from the light source 14 passes through the light-projecting lens 15 and is converted into slit light L1. The housing 10 is provided with a light-projecting window 16 through which the slit light L1 passes. Similarly, the housing 10 is provided with a light-receiving window 17 through which reflected light L2 is guided into the housing 10.

[0128] The light-receiving lens 12 is a lens for focusing the reflected light L2 on the imaging unit 13. The imaging unit 13 is a sensor having a plurality of pixels (which may also be called light-receiving elements or photoelectric conversion elements) arranged two-dimensionally. As shown in FIG. 12, the light-receiving axis AX2 of the imaging unit 13 is tilted at an angle θ1 with respect to the light projection axis AX1 of the light source 6. In other words, the reflected light L2 from height Z0 is focused at a position V0 in the V direction of the imaging unit 13. The reflected light L2 from height Z1 is focused at a position V1 in the V direction of the imaging unit 13. The reflected light L2 from height Z2 is focused at a position V2 in the V direction of the imaging unit 13. In this way, the V direction of the imaging unit 13 corresponds to the Z direction of the workpiece W. Although the U direction of the imaging unit 13 is not shown, the U direction corresponds to the X direction of the workpiece W. In other words, the vertical direction of the image, which is the light reception result output by the imaging unit 13, is the V direction, and the horizontal direction is the U direction.

[0129] In Figure 12, the light source 14 is positioned so that the slit light L1 is output in the Z-axis direction, but the positional relationship between the pair of light source 14 and projector lens 15 and the pair of imaging unit 13 and receiver lens 12 may be reversed.

[0130] <Position (height calculation)> 13 is a diagram illustrating 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 that reflected light L2 brings to the light receiving surface of image capture unit 13 also becomes wide enough to span multiple photoelectric conversion elements.

[0131] Therefore, the optical displacement meter 1 obtains an approximate curve P1 indicating the change in brightness value from the brightness value of each pixel, and calculates the position in the V direction where the approximate curve P1 produces a peak value. In Figure 13, the leftmost column is the target column, and an example of the distribution of brightness values ​​(approximate curve P1) for the target column is shown. The approximate curve P1 is obtained by curve fitting multiple sample values, for example. Sample values ​​below the detection threshold are not taken into account. The position in the V direction where this peak value produces indicates the height of the workpiece W. The optical displacement meter 1 obtains an approximate curve P1 at each position (each pixel column) in the U direction, and calculates the position (height) in the V direction where the peak value produces from the approximate curve P1. By performing this calculation process at each position in the U direction, a single profile can be obtained. This type of calculation process may be referred to as subpixel processing.

[0132] Note that, for example, a coordinate conversion condition (e.g., a coordinate conversion table) indicating the correspondence between the UV coordinates and the relative position y in the Y direction between the optical displacement meter 1 and the workpiece W, as expressed by (U, V, y) = (X, Y, Z), and the local coordinates (X, Y, Z), is generated by pre-shipment calibration 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 relative position y in the Y direction between the optical displacement meter 1 and the workpiece W through simple calculations. Note that, in the coordinate conversion, equal-interval correction is performed in the X and Y directions so that positions in the X and Y directions are plotted at equal intervals, and Z corresponding to the corrected (X, Y) may be obtained by linear interpolation or the like and output as the measurement result. Image processing performed on the measurement results often assumes data sampled at equal intervals in the X and Y directions, so equal-interval correction facilitates subsequent image processing.

[0133] <Function block> 14 is a functional block diagram of the optical displacement meter 1. The optical displacement meter 1 includes a light emitting / receiving module 20 and a control unit 22.

[0134] The light emitting / receiving module 20 integrally holds the light emitting unit 11, the light receiving lens 12, and the imaging unit 13.

[0135] The control unit 22 includes a signal processing unit 24 and a communication unit 25. The signal processing unit 24 controls the light projecting unit 11 to cause the light projecting unit 11 to irradiate the slit light L1.

[0136] The signal processing unit 24 includes a peak detection unit 241 , a profile generation unit 242 , a three-dimensional data generation unit 243 , and an inspection unit 244 .

[0137] The peak detection unit 241 detects the position in the V direction (peak position) that brings about the peak of the brightness value based on the light reception result output from the imaging unit 13. The profile generation unit 242 generates one profile data by summarizing the height (zi) of the workpiece W at each position (xi) in the X direction determined by the peak detection unit 241. The three-dimensional data generation unit 243 generates three-dimensional shape data of the workpiece W from the profiles of the workpiece W with different yi generated by the profile generation unit 242.

[0138] The inspection unit 244 inspects the workpiece W based on the three-dimensional shape data of the workpiece W generated by the three-dimensional data generation unit 243. The inspection unit 244 performs predetermined measurements on the three-dimensional shape data of the workpiece W, and inspects the workpiece W based on the measurement results. For example, the inspection unit 244 measures the length, angle, etc. of a predetermined portion of the workpiece W. Then, the inspection unit 244 determines whether the workpiece W is a non-defective product based on these measurement results and preset thresholds, etc.

[0139] At least a part of the peak detection unit 241, the profile generation unit 242, the three-dimensional data generation unit 243, and the inspection unit 244 may be provided in a location (for example, inside the control device 2 shown in FIG. 11) separate from the main body of the optical displacement meter 1. In this case, the optical displacement meter 1 has a separate structure consisting of the main body of the optical displacement meter 1 and a separate part of the optical displacement meter 1.

[0140] The communication unit 25 communicates with the control device 2 via wired or wireless communication. 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, and inspection results of the workpiece W determined by the inspection unit 244, to the control device 2.

[0141] <Processing flow> In this embodiment, the motor 21 in the first embodiment is replaced with a drive motor for the belt conveyor 5, and while the scanning direction was the rotation direction of the light emitting and receiving module 20 in the first embodiment, in this embodiment it is the transport direction (Y direction) of the workpiece W by the belt conveyor 5. Therefore, by changing the motor and the contents of the coordinate conversion, the processing flows shown in Figures 6 to 8 can also be applied to this embodiment.

[0142] <Modification of relative movement> 11, the workpiece W is moved in the Y direction by a belt conveyor 5 relative to the light emitting and receiving module 20 of the optical displacement meter 1, thereby measuring the profile and three-dimensional shape of the workpiece W. In this embodiment, the workpiece W moves, but the relative movement between the workpiece W and the light emitting and receiving module 20 of the optical displacement meter 1 is not limited to this. Therefore, the workpiece W may remain stationary and the light emitting and receiving module 20 of the optical displacement meter 1 may move, or both the workpiece W and the light emitting and receiving module 20 of the optical displacement meter 1 may move.

[0143] 15 , when the light emitting and receiving module 20 of the optical displacement meter 1 is moved, the optical displacement meter 1 includes a linear motion mechanism 26, and the control unit 22 includes a linear motion mechanism control unit 27. The linear motion mechanism control unit 27 controls the linear motion mechanism 26 to move the light emitting and receiving module in the Y direction within the housing 10.

[0144] <<Others>> In addition to the above-described embodiments, the 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-described embodiments should be considered to be illustrative and not restrictive in all respects. Furthermore, 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 of the claims.

[0145] For example, in the above-described embodiment, the exposure time setting, the peak width filter setting, and the peak selection setting are performed in stages, but the exposure time setting and the peak width filter setting may be performed all at once, or the exposure time setting, the peak width filter setting, and the peak selection setting may be performed all at once.

[0146] When the exposure time and the filter width are set at the same time, for example, when there are four options for the exposure time, peak width filtering is performed on the multiple light receiving images acquired with the first exposure time using each parameter of the peak width filter, then peak width filtering is performed on the multiple light receiving images acquired with the second exposure time using each parameter of the peak width filter, then peak width filtering is performed on the multiple light receiving images acquired with the third exposure time using each parameter of the peak width filter, and finally peak width filtering is performed on the multiple light receiving images acquired with the fourth exposure time using each parameter of the peak width filter.

[0147] Furthermore, for example, so that the imaging navigation program can be compatible with multiple types of optical displacement meters 1, the storage unit of the control device 2 may store different default control conditions depending on the measurement distance of the light emitting and receiving module 20, and an input field for the measurement distance of the light emitting and receiving module may be provided on the setting screen 300. In this case, when the control device 2 receives input of the measurement distance of the light emitting and receiving module 20 via the setting screen 300, it simply reads out the corresponding default control condition from the storage unit. [Explanation of symbols]

[0148] 1 Optical displacement gauge 2. Control device 3 Display device 4 Input Devices 5 Belt conveyor 10. Housing 11 Light projector 12 Receiving lens 13 Imaging unit (image sensor) 14 Light source 15 Projection lens 16 Floodlight 17 Light receiving window 18 Light receiving part 19 Reflective material 20 Light emitting and receiving module 21 Motor 22 Control Unit 23 Motor control unit 24 Signal Processing Section 25 Communications Department 26 Linear motion mechanism 27 Linear motion mechanism control unit 100 Optical displacement measurement system 241 Peak detector 242 Profile Generation Unit 243 3D Data Generation Unit 244 Inspection Department 310 Image display area 311 Image Type Display Display Banner 312 Enlarge button 313 Shrink button 314 Angle change button 315 Maximum display button 316 Minimum display button 317 Forward button 318 Reverse button 320 Operation area 321A Exposure time active setting field 321B Peak Width Filter Active Settings 321C Peak selection active setting field 322A 2D display switch button 322B 3D display switch button 323 Image update button 324A Back button 324A 324B Next button 325A Done button 325B Cancel button 330 Progress display area AX1 light emitting axis AX2 optical axis AX3 Rotation Axis I1 Image L1 slit light L2 reflected light R1 area double work

Claims

1. a light-emitting / receiving module including: a light-emitting unit that irradiates a workpiece with slit light extending in an X direction; and an image sensor that has a plurality of pixels two-dimensionally arranged in a U direction corresponding to the X direction and a V direction orthogonal to the U direction, receives light reflected by the workpiece with the plurality of pixels, and outputs a light-receiving image showing a distribution of the amount of received light; a movement mechanism that moves the light emitting and receiving module and the workpiece relative to each other; a setting device for setting control conditions for the light emitting and receiving module and the movement mechanism; a control unit that controls the light emitting and receiving module and the moving mechanism based on the control conditions; Equipped with the control conditions include a plurality of different exposure times of the image sensor; The control unit The light emitting and receiving module is controlled so as to sequentially acquire a plurality of the received light images of the workpiece based on each of the plurality of exposure times while the movement mechanism moves the light emitting and receiving module and the workpiece relatively within each measurement range including at least a common range; For each of the plurality of exposure times, XYZ coordinate information indicating the shape of the workpiece is acquired based on the plurality of received light images, and a workpiece image indicating the shape of the workpiece is generated based on the XYZ coordinate information; generating a setting screen that displays a plurality of the workpiece images corresponding to each of the plurality of exposure times; the setting device is configured to accept, via the setting screen, a selection of one exposure time from the plurality of exposure times, and then accept adjustment of image processing parameters to be executed on the plurality of received-light images acquired based on the selected exposure time. Optical displacement measurement system.

2. a light-emitting / receiving module including: a light-emitting unit that irradiates a workpiece with slit light extending in an X direction; and an image sensor that has a plurality of pixels two-dimensionally arranged in a U direction corresponding to the X direction and a V direction orthogonal to the U direction, receives light reflected by the workpiece with the plurality of pixels, and outputs a light-receiving image showing a distribution of the amount of received light; a movement mechanism that moves the light emitting and receiving module and the workpiece relative to each other; a setting device for setting control conditions for the light emitting and receiving module and the movement mechanism; a control unit that controls the light emitting and receiving module and the moving mechanism based on the control conditions; Equipped with the control conditions include a plurality of different exposure times of the image sensor; The control unit The light emitting and receiving module is controlled so as to sequentially acquire a plurality of the received light images of the workpiece based on each of the plurality of exposure times while the movement mechanism moves the light emitting and receiving module and the workpiece relatively within each measurement range including at least a common range; For each of the plurality of exposure times, XYZ coordinate information indicating the shape of the workpiece is acquired based on the plurality of received light images, and a workpiece image indicating the shape of the workpiece is generated based on the XYZ coordinate information; generating a setting screen that displays a plurality of the workpiece images corresponding to each of the plurality of exposure times; the control conditions include the measurement range, drive control parameters including a movement speed of the movement mechanism, and the number of times the image sensor captures images within the measurement range; the setting device determines the drive control parameters based on the measurement range, the number of times the image sensor captures images within the measurement range, and each of the plurality of exposure times. Optical displacement measurement system.

3. the plurality of exposure times includes a first exposure time and a second exposure time different from the first exposure time, The control unit controlling the image sensor to acquire a plurality of the received-light images of the workpiece based on the first exposure time while moving the light emitting and receiving module and the workpiece relatively within one of the measurement ranges by the movement mechanism; 3. The optical displacement measurement system according to claim 1, wherein, after the acquisition of the plurality of light-receiving images based on the first exposure time is completed, the movement mechanism automatically controls the light-emitting / receiving module and the workpiece to move relative to each other within another measurement range, while the system controls the acquisition of the plurality of light-receiving images of the workpiece based on the second exposure time.

4. The control unit 4. The optical displacement measurement system according to claim 3, wherein a plurality of the received light images are acquired based on the second exposure time while the XYZ coordinate information is acquired based on the plurality of received light images acquired with the first exposure time.

5. the setting device further includes a storage unit that stores the XYZ coordinate information for each of the plurality of exposure times; The control unit An optical displacement measurement system as described in claim 1 or 2, wherein when an instruction to switch between a distance image showing the Z-direction height of the work in the XY plane or a three-dimensional image showing the three-dimensional shape of the work is received via the setting screen, the setting screen is generated based on the XYZ coordinate information stored in the memory unit and switched to the distance image or the three-dimensional image in accordance with the switching instruction.

6. generating the setting screen on which a plurality of the workpiece images corresponding to at least two of the plurality of exposure times are displayed side by side; The optical displacement measurement system of claim 5, wherein when the switching instruction is received for one of the plurality of workpiece images displayed side by side, the switching instruction is also applied to the remaining plurality of workpiece images displayed side by side.

7. the plurality of exposure times includes a first exposure time and a second exposure time different from the first exposure time, The control unit generating the setting screen that displays the workpiece image corresponding to the first exposure time; 6. The optical displacement measurement system according to claim 5, wherein, when an instruction to display the workpiece image corresponding to the second exposure time on the setting screen is received, the switching instruction for the workpiece image corresponding to the first exposure time is also applied to the workpiece image corresponding to the second exposure time, and the workpiece image corresponding to the second exposure time is displayed on the setting screen.

8. The control unit generating the setting screen on which a plurality of the workpiece images corresponding to at least two of the plurality of exposure times are displayed side by side; 3. The optical displacement measurement system of claim 1, wherein when an instruction to change the display conditions, including zoom and angle, for one of the plurality of workpiece images displayed side by side is received, the remaining plurality of workpiece images displayed side by side are also displayed on the setting screen based on the changed display conditions.

9. the plurality of exposure times includes a first exposure time and a second exposure time different from the first exposure time, The control unit generating the setting screen that displays the workpiece image corresponding to the first exposure time; 3. The optical displacement measurement system according to claim 1, wherein, when an instruction to display the work image corresponding to the second exposure time on the setting screen is received, the work image corresponding to the second exposure time is displayed on the setting screen while maintaining display conditions including zoom and angle for the work image corresponding to the first exposure time.

10. The control unit When a change to at least one of the plurality of exposure times is accepted via the setting screen, the light emitting and receiving module is controlled so as to sequentially acquire a plurality of the received light images of the workpiece while the movement mechanism moves the light emitting and receiving module and the workpiece relatively within the measurement range based on the control conditions including the exposure time related to the change; 3. The optical displacement measurement system according to claim 1, wherein the changed XYZ coordinate information is obtained based on a plurality of received light images during the exposure time related to the change, the changed workpiece image is generated based on the changed XYZ coordinate information, and the display on the setting screen is updated.

11. the control conditions include the measurement range, drive control parameters including a movement speed of the movement mechanism, and the number of times the image sensor captures images within the measurement range; The optical displacement measurement system according to claim 1 , wherein the setting device determines the drive control parameters based on the measurement range, the number of times the image sensor captures images within the measurement range, and each of the plurality of exposure times.

12. the control conditions further include a unit measurement time for measuring one two-dimensional cross-sectional profile based on the received light image; The setting device includes: determining a scanning time required to scan the measurement range based on the unit measurement time and the number of times the image sensor captures images within the measurement range; The optical displacement measurement system according to claim 11 , wherein the movement speed is determined based on the measurement range and the scanning time.

13. the drive control parameters further include acceleration and deceleration of the moving mechanism; The setting device includes:

12. The optical displacement measurement system according to claim 11, wherein the optical displacement measurement system calculates the acceleration and acceleration start position required for the light projecting and receiving module to reach the moving speed at the time when the light projecting and receiving module starts measurement within the measurement range, and the deceleration and stop position required for the light projecting and receiving module to stop after finishing measurement within the measurement range.

14. 3. The optical displacement measurement system according to claim 1, wherein the setting device receives a selection of one exposure time from the plurality of exposure times, and then sequentially performs image processing using each of a plurality of peak detection parameters on the plurality of light-receiving images acquired based on the selected exposure time or on peak candidate information acquired from the plurality of light-receiving images, and displays a plurality of the workpiece images corresponding to each of the plurality of peak detection parameters.

15. the setting device further includes a storage unit that stores different default control conditions depending on the measurement distance of the light emitting and receiving module; 3. The optical displacement measurement system according to claim 1, wherein the setting device, upon receiving an input of a measurement distance of the light emitting and receiving module via the setting screen, reads out the corresponding default control condition from the storage unit.

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