JP2018072267A - Image measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve usability, while suppressing reduction of a measurement accuracy.SOLUTION: An image measurement device 1 includes: an imaging part 201 for imaging a work W mounted on a stage 23; and a probe 26 having a contact part 261 capable of contacting a side surface of the work W mounted on the stage 23 in a view field of the imaging part 201. The image measurement device 1 further includes: a horizontal drive part 24 for moving at least one of either the stage 23 or the probe 26 substantially in parallel with the mounting surface of the stage 23; and a measurement part (contact position specifying part) for measuring a position of a side surface of the work W using an image when the contact part 261 and the side surface of the work W are brought into contact each other. Particularly, the image measurement device 1 includes: a shape determination part for determining whether a shape of the contact part 261 in the image of the contact part 261 generated by the imaging part 201 is a predetermined shape or not and a result output part for outputting a determination result of the shape determination part; and a display part 21.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image measuring apparatus, and more particularly, to an improvement in an image measuring apparatus that obtains the dimensions of a workpiece by bringing a probe into contact with a workpiece on a stage and detecting the position of the probe with an image.

  The image measuring device is a dimension measuring device that captures a workpiece placed on a stage to acquire a workpiece image, extracts an edge from the workpiece image, and obtains a workpiece dimension. Regardless of the position in the height direction of the camera, the workpiece image is a very accurate similar shape to the workpiece. By detecting the distance and angle on the workpiece image, the actual size and angle on the workpiece are detected. can do. Edge extraction is performed by analyzing the brightness change of the workpiece image, detecting edge points, and fitting a plurality of detected edge points with geometric figures such as straight lines, circles, arcs, etc. A boundary, a contour of a concave portion or a convex portion on the workpiece, and the like are obtained as edges. The dimension of the workpiece is obtained as the distance or angle between the edges obtained in this way. Further, the quality of the workpiece is determined by comparing the difference (error) between the obtained dimension value and the design value with a tolerance.

  Some image measuring apparatuses as described above obtain the dimensions of a workpiece by bringing a probe into contact with the side surface of the workpiece placed on a stage (Non-Patent Document 1). The probe is disposed in the imaging field of view of the camera, and the contact position with the workpiece is obtained by specifying the position of the probe from an image obtained by photographing the probe in contact with the side surface of the workpiece.

Guijun Ji, Heinrich Schwenke, Eugen Trapet, “An Opto-mechanical Microprobe System for Measuring Berry Small Parts on CMMs (An Opto-mechanical MicroSrobe) USA), International Society of Optical Engineering (SPIE) Vision Geometry VII (Vision Geometry VII), July 20-22, 1998, 3454, p. 348-353

33 and 34 are diagrams illustrating an example of the operation of the image measurement apparatus. 33A shows the workpiece W to be measured, and FIG. 33B shows the workpiece image Iw. The workpiece W includes a base member w ₁ and two protrusions w ₂ formed on the base member w ₁ . The distance A between the inner side surface Sa of the two protrusions w _2, when measuring the distance B between the outer side surface Sb, and the distance C between the side surfaces Sc of the base member w _1, the interior sides of the protruding portion w ₂ Is a curved surface shape, it is difficult to accurately specify the edge of the side surface Sa from the work image Iw as compared to the edges of the side surfaces Sb and Sc.

The (a) of FIG. 34, indicated workpiece image Iw taken in a state in contact with the side surface Sa of the right protrusion w ₂ the probe Pr is, the (b) is a probe Pr left projecting portions A work image Iw photographed while being in contact with the side surface Sa of w ₂ is shown. The position of the probe Pr in the work image Iw can be accurately specified since the shape and size of the probe Pr are known. Further, the position of the side surface Sa is obtained by specifying the contact position from the displacement amount of the probe Pr within the imaging field of view. Therefore, if this type of image measuring apparatus is used, it is possible to accurately determine the dimensions even at a measurement location where the edge cannot be accurately specified from the work image Iw.

  By the way, in the image measuring apparatus using the probe Pr, it is assumed that the shape and size of the probe Pr are maintained in a known shape and size. Therefore, if oil or dust adheres to the spherical contact portion provided at the tip of the probe Pr, the measurement accuracy at the position where the contact portion contacts the workpiece W is lowered. Since the measurement accuracy of the image measuring apparatus is on the order of micrometers, even if there is a deposit that cannot be visually confirmed, a measurement error is caused. Therefore, if the user cleans the contact portion before each measurement, the measurement accuracy can be maintained, but it will be a burden on the user. Therefore, usability will be improved if a warning can be issued when a deposit that actually affects the measurement accuracy is adhered to the contact portion and the user can be prompted to perform cleaning. Accordingly, an object of the present invention is to improve usability while suppressing a decrease in measurement accuracy.

An image measuring apparatus according to the first aspect of the present invention includes:
A stage on which the workpiece is placed;
An imaging unit that images the workpiece placed on the stage and generates an image;
In the field of view of the imaging unit, a probe having a contact part that can come into contact with the side surface of the workpiece placed on the stage;
A drive unit that moves at least one of the stage and the probe substantially parallel to the mounting surface of the stage;
An image measuring apparatus comprising: a measuring unit that measures a position of the side surface of the workpiece using an image generated by the imaging unit when the contact unit and the side surface of the workpiece are in contact with each other;
A shape determination unit that determines whether the shape of the contact part in the image of the contact part generated by the imaging unit is a predetermined shape;
And an output unit that outputs a determination result of the shape determination unit.

  According to the present invention, since a determination result indicating whether the shape of the contact portion is a predetermined shape is output, the user can perform cleaning of the contact portion based on the determination result. Thus, usability can be improved while suppressing a decrease in measurement accuracy.

1 is a system diagram illustrating a configuration example of an image measurement device 1 according to an embodiment of the present invention. It is explanatory drawing which showed typically an example of operation | movement of the image measuring apparatus 1 of FIG. It is explanatory drawing which showed typically an example of the operation | movement at the time of making the probe 26 contact the workpiece | work W on the stage 23. FIG. FIG. 2 is a diagram illustrating an example of the operation of the image measurement apparatus 1 in FIG. 1, in which the position D of the contour line 14 is specified and the distance D between the side surfaces of the workpiece W is calculated. FIG. 2 is a block diagram illustrating a configuration example of a controller 3 in FIG. 1. FIG. 6 is a block diagram illustrating a configuration example of an input receiving unit 311 in FIG. 5. It is the figure which showed an example of the operation | movement at the time of the contact position designation | designated in the input reception part 311 of FIG. It is the figure which showed an example of the operation | movement at the time of the pattern image registration in the input reception part 311 of FIG. FIG. 6 is a diagram illustrating an example of an operation at the time of designating a contact position in the input reception unit 311 in FIG. 5, in which a table in which shape types are associated with the number of scan paths is illustrated. FIG. 6 is a diagram illustrating an example of an operation at the time of designating a scan position in the input management unit 311 in FIG. 5, in which the number of scan paths varies depending on the length of the contour line L. FIG. 6 is a block diagram illustrating a configuration example of a measurement control unit 315 in FIG. 5. 6 is a flowchart showing an example of an operation at the time of measurement setting in the controller 3 of FIG. 5. It is the figure which showed an example of the operation | movement at the time of the measurement setting in the image measuring device 1 of FIG. 1, and the workpiece | work W and pattern image Ip of registration object are shown. FIG. 2 is a diagram illustrating an example of an operation at the time of measurement setting in the image measurement apparatus 1 of FIG. It is the figure which showed the tolerance setting screen 101 at the time of designation | designated of a design value and tolerance. It is the figure which showed the feature-value setting screen 102 at the time of designation | designated of feature-value information. FIG. 13 is a flowchart showing an example of a detailed operation for step S103 (setting of an image measurement element) in FIG. FIG. 2 is a diagram illustrating an example of an operation when setting an image measurement element in the image measurement apparatus 1 of FIG. 1. FIG. 13 is a flowchart showing an example of a detailed operation in step S104 (probe measurement element setting) in FIG. It is the figure which showed an example of the operation | movement at the time of the setting of the probe measurement element in the image measuring apparatus 1 of FIG. It is the figure which showed the operation example in the case of adjusting the contact target position on the model image Im. It is the figure which showed the operation example in case the start position of scanning operation | movement interferes with another site | part. It is the figure which showed the operation example in the case of adjusting the height position of scanning operation | movement on the model image Im. It is the figure which showed the operation example in the case of designating the movement method at the time of the probe 26 moving between contact target positions. 13 is a flowchart showing an example of detailed operation for step S107 (registration of feature amount information) in FIG. FIG. 26 is a flowchart showing an example of detailed operations in step S201 in FIG. 17, step S301 in FIG. 19, and step S401 in FIG. 25 (designation of shooting conditions). It is the flowchart which showed an example of the operation | movement at the time of the continuous measurement in the controller 3 of FIG. It is the flowchart which showed an example of the operation | movement at the time of the continuous measurement in the controller 3 of FIG. It is the figure which showed an example of the operation | movement at the time of the continuous measurement in the image measuring apparatus 1 of FIG. It is the figure which showed an example of the operation | movement at the time of the continuous measurement in the image measuring apparatus 1 of FIG. It is the figure which showed an example of the operation | movement at the time of the continuous measurement in the image measuring apparatus 1 of FIG. FIG. 29 is a flowchart showing an example of detailed operation for step S615 (scan operation) in FIG. 28. FIG. It is the figure which showed the operation example of the conventional image measuring apparatus. It is the figure which showed the operation example of the conventional image measuring apparatus. It is a figure explaining a deposit. It is a figure explaining the function involved in the detection of a deposit | attachment. It is a flowchart explaining a probe check process. It is a flowchart explaining the detection process of the deposit | attachment based on roundness. It is a flowchart explaining the detection process of the deposit | attachment based on an image comparison. It is a flowchart explaining the detection process of the deposit | attachment based on a diameter. It is a figure explaining the difference of the image based on the presence or absence of light emission of a contact part. It is a figure which shows UI which shows a determination result.

<Image measuring device 1>
FIG. 1 is a system diagram showing a configuration example of an image measuring apparatus 1 according to an embodiment of the present invention. The image measuring apparatus 1 extracts an edge from a workpiece image obtained by photographing the workpiece W on the stage 23, and specifies the contact position by bringing the probe 26 into contact with the workpiece W on the stage 23. Is a dimension measuring instrument for determining the dimensions of the main body 2, and comprises the main body 2, the controller 3, the keyboard 41 and the mouse 42. The workpiece W is a measurement object whose shape and dimensions are measured.

  The main body 2 includes a measurement unit 20, a display unit 21, a vertical drive unit 22, a stage 23, a horizontal drive unit 24, and a transmission illumination unit 25, and irradiates the work W on the stage 23 with detection light made of visible light. The transmitted light or reflected light is received to generate a work image. If the front direction of the display unit 21 is referred to as the front-rear direction, the display unit 21 is arranged in front of the measurement unit 20.

  Here, the process of extracting the edge from the workpiece image and obtaining the dimension of the workpiece W is called image measurement, and the position of the probe 26 is detected from the workpiece image in a state where the probe 26 is in contact with the side surface of the workpiece W. The process for obtaining the dimensions of the workpiece W by specifying the coordinates of the contact position between the workpiece 26 and the workpiece W will be referred to as probe measurement.

  The display unit 21 is a display device that displays work images and measurement results. The vertical driving unit 22 relatively moves the measurement unit 20 and the stage 23 in the vertical direction in order to adjust the height of the focus position with respect to the stage 23 and the height of the probe 26. The vertical drive unit 22 can move the measurement unit 20 in the vertical direction. Note that the vertical drive unit 22 may be configured such that the height of the probe 26 can be individually adjusted with respect to the measurement unit 20.

  The stage 23 is a work table having a horizontal and flat mounting surface for mounting the workpiece W. For example, the stage 23 is made of a glass plate that transmits detection light. The horizontal driving unit 24 relatively moves the measurement unit 20 and the stage 23 in a direction parallel to the upper surface of the stage 23 in order to adjust the position of the imaging field of view with respect to the stage 23 and the position of the probe 26. The horizontal drive unit 24 can move the stage 23 in an arbitrary direction within a horizontal plane.

  The transmitted illumination unit 25 is a light projecting device that irradiates the workpiece W on the stage 23 with detection light from below, and includes a transmitted illumination light source 251, a mirror 252, and a condenser lens 253. The transmitted illumination light source 251 is disposed facing forward. The detection light emitted from the transmitted illumination light source 251 is reflected upward by the mirror 252 and emitted through the condenser lens 253. This detection light passes through the stage 23, a part of the transmitted light is blocked by the work W, and the other part enters the objective lens 205 of the measurement unit 20.

<Measurement unit 20>
The measurement unit 20 is a light projecting / receiving unit that irradiates the workpiece W on the stage 23 with detection light and receives detection light from the workpiece W, and includes a probe 26, a switching drive unit 27, imaging units 201 and 206, and a half mirror 204. 210, the objective lens 205, the coaxial epi-illumination light source 209, the ring illumination unit 211, the ring illumination vertical drive unit 212, and the probe light source 263.

  The objective lens 205 is a light receiving lens that condenses detection light from the workpiece W, and is disposed so as to face the stage 23. The imaging units 201 and 206 are cameras that capture the workpiece W on the stage 23 via the common objective lens 205 and generate workpiece images, respectively.

  The imaging unit 201 is an imaging device with a low imaging magnification, and includes an imaging element 202 and a low-magnification side imaging lens unit 203 including an imaging lens and a diaphragm plate. The image sensor 202 receives the detection light from the workpiece W via the low magnification side imaging lens unit 203 and generates a workpiece image. The image sensor 202 is arranged with the light receiving surface facing downward.

  The imaging unit 206 is an imaging device having a high imaging magnification, and includes an imaging element 207 and a high-magnification imaging lens unit 208 including an imaging lens and a diaphragm plate. The imaging field of view is coaxial with the imaging field of the imaging unit 201. Is formed on the stage 23. The image sensor 207 receives detection light from the work W via the high magnification side imaging lens unit 208 and generates a work image. The image sensor 207 is arranged with the light receiving surface facing forward. The detection light transmitted through the objective lens 205 is reflected backward by the half mirror 204 and forms an image on the image sensor 207 via the high magnification side imaging lens unit 208.

  For the imaging elements 202 and 207, for example, an image sensor such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) is used. As the objective lens 205, a telecentric lens having a property that the size of the image is not changed even when the position in the optical axis direction of the objective lens 205 is changed is used.

  The coaxial epi-illumination light source 209 is a light projecting light source device for irradiating the workpiece W on the stage 23 with detection light from vertically above, and is arranged facing forward. Detection light emitted from the coaxial epi-illumination light source 209 is reflected downward by the half mirror 210 and emitted through the objective lens 205.

  The ring illumination unit 211 is a light projecting device that irradiates the workpiece W on the stage 23 with detection light from above or from the side, and has a ring shape surrounding the objective lens 205. The ring illumination vertical drive unit 212 moves the ring illumination unit 211 in the vertical direction in order to adjust the irradiation angle of the detection light with respect to the stage 23. As a method for illuminating the workpiece W, any one of transmitted illumination, ring illumination, and coaxial epi-illumination can be selected.

<Probe 26>
The probe 26 is a contact for contacting the side surface of the workpiece W placed on the stage 23 and measuring the dimension of the workpiece W. The probe 26 is disposed so as to be movable between an imaging field of the imaging unit 201 and a retracted position. The probe 26 is a self-luminous probe, and includes a spherical contact portion 261 that contacts the workpiece W and a metal tube 262 that transmits guide light.

  An optical fiber for transmitting guide light is included inside the metal tube 262. The metal tube 262 is formed of a SUS tube having sufficient strength, and the shape of the metal tube 262 does not change even if the contact portion 261 contacts the workpiece W.

  The contact portion 261 is disposed at the tip of a metal tube 262 extending from the probe light source 263, and diffuses and emits guide light. Since the cross-sectional area in the horizontal direction of the spherical contact portion 261 is larger than the cross-sectional area in the horizontal direction of the metal tube 262, even when the contact portion 261 is imaged from above by the imaging portion 201, the contact portion 261 contours can be imaged. The probe light source 263 is a light source device that generates guide light made of visible light and makes it incident on the metal tube 262.

  The switching drive unit 27 is a horizontal drive unit that switches between a state in which the probe 26 is positioned at a measurement position in the imaging field of view and a state in which the probe 26 is positioned in a retracted position that is moved away from the center of the imaging field of view. . The switching drive unit 27 is a rotation drive unit that rotates the probe light source 263 around the rotation axis in the vertical direction. By rotating the probe light source 263, the probe 26 is moved between the retracted position and the measurement position. Move. For example, the retracted position is preferably outside the imaging field of the imaging unit 201, but may be the peripheral part of the imaging field if the probe 26 is not reflected as a subject in the work image.

  The controller 3 is a control unit that controls photographing and screen display by the main body 2, analyzes the work image, and obtains the dimensions of the work W by calculation, and is connected to a keyboard 41 and a mouse 42. The keyboard 41 and the mouse 42 are the input unit 4 on which a user performs operation input.

  2-4 is explanatory drawing which showed typically an example of operation | movement of the image measuring apparatus 1 of FIG. FIG. 2 shows a state where the probe 26 extending from the mounting arm 264 is viewed from above. (A) in the figure shows the case where the probe 26 is in the measurement position, and (b) shows the case where the probe 26 is in the retracted position.

  The attachment arm 264 is an attachment member for attaching the probe 26 to the housing of the measurement unit 20 and has an L shape. A vertical rotation shaft 265 is disposed at one end of the mounting arm 264, and the probe 26 projects from the other end surface. The mounting arm 264 supports the metal tube 262 with a floating structure. When the contact portion 261 contacts the side surface of the workpiece W, the metal tube 262 is offset in the X and Y directions without being deformed by the contact. As a result, the position of the contact portion 261 changes on the work image.

  The imaging area 11 is an area on the stage 23 corresponding to the imaging field of view of the imaging unit 201 and has a rectangular shape. The translucent area 12 is a circular area on the stage 23 that is irradiated with detection light from the transillumination unit 25, and is formed in the imaging area 11.

  When the probe 26 is at the measurement position, the contact portion 261 is disposed at the center of the imaging area 11 and the light transmitting area 12. The contact part 261 is reflected as a subject on the work image photographed in this state. By controlling the switching drive unit 27 and rotating the mounting arm 264 about 180 ° from the state where the probe 26 is at the measurement position, the probe 26 is moved to the retracted position.

  The retracted position is a position for retracting the probe 26 so that the probe 26 is not reflected as a subject in the work image. When the probe 26 is in the retracted position, the contact portion 261 and the metal tube 262 are disposed outside the imaging area 11.

  FIG. 3 shows an example of the operation when the probe 26 is brought into contact with the workpiece W on the stage 23. (A) in the figure shows a case where the probe 26 is moved relative to the stage 23 to the position corresponding to the start position of the scan path at the reference height, and (b) shows the reference height. The case where the probe 26 is moved vertically downward from the height to the measurement height is shown. (C) in the drawing shows a case where the probe 26 is moved relative to the stage 23 along the scanning path at the measurement height.

  In dimension measurement using the probe 26, a contact target position when the probe 26 is brought into contact with the side surface of the workpiece W and a scan path passing through the contact target position are designated in advance. The reference height is a height at which the probe 26 does not interfere with the workpiece W on the stage 23. By controlling the horizontal drive unit 24, the probe 26 can be moved in the horizontal direction relative to the stage 23 at the reference height. The reference height may be configured to be specified such that the tip of the probe 26 is outside the depth of field range of the imaging unit 201 or 206.

  The measurement height is the height of the side surface of the workpiece that the probe 26 should contact, and the vertical position is lower than the reference height. The vertical drive unit 22 switches the height of the probe 26 with respect to the stage 23 between a measurement height and a reference height higher than the measurement height. If the probe 26 is moved relative to the stage 23 in the scanning direction from the start position to the end position along the scan path, the contact portion 261 can be brought into contact with the side surface of the workpiece W. If it is detected that the probe 26 contacts the side surface of the workpiece W, the probe 26 immediately stops with respect to the stage 23.

  The start position of the scan path is an operation start position for starting the above-described scan operation, and the end position is an operation end position for ending the scan operation. By determining the end position, a contact error can be detected when the probe 26 reaches the end position. The start position and the end position of the scan path are set on a scan path that passes through the contact target position and extends along the normal line of the contour line of the workpiece W.

  FIG. 4 shows a case where the distance D between the side surfaces of the workpiece W is calculated by specifying the position of the contour line 14. (A) in the drawing shows the workpiece W to be measured and the probe 26 brought into contact with the right side surface of the workpiece W. The workpiece W has a stepped step, and a distance D between the upper right side surface and the left side surface is measured.

  (B) in the drawing shows a work image Iw composed of a transmission image captured by transmission illumination. In the transmission image, it is possible to specify the outer edge of the workpiece W by edge extraction, but it is difficult to specify the contour line inside the outer edge by edge extraction.

  (C) in the figure shows a work image Iw composed of a reflected image captured by reflected illumination. The reflected illumination is an illumination method using coaxial epi-illumination or ring illumination, and even a contour line inside the outer edge of the workpiece W can be specified by edge extraction. However, since the upper part of the workpiece W has a curved upper surface, it is difficult to accurately identify the right side contour line by edge extraction compared to the left side contour line. In such a case, the contour line 14 on the right side surface can be accurately specified by bringing the probe 26 into contact.

  In the work image Iw shown in FIG. 5C, the right side outline 14 specified by contacting the probe 26 and the left side outline 14 specified by extracting an edge from the edge extraction region 15 are included. It is displayed.

  The contact of the probe 26 with the side surface of the workpiece W can be detected based on whether or not the position on the workpiece image Iw of the contact portion 261 moving along the scan path has changed by a predetermined threshold value or more within a predetermined time. . The position of the contact part 261 is specified by obtaining the center of the circle from the edge of the contact part 261, for example. Further, on the workpiece image Iw when the probe 26 contacts the side surface of the workpiece W, the normal direction of the side surface of the workpiece W and the contact position 13 can be specified from the displacement direction of the contact portion 261 with respect to the center of the imaging field of view. it can.

  In the case of a configuration in which the probe 26 itself is moved horizontally, contact with the workpiece side surface is detected depending on whether or not the contact portion 261 moving along the scan path has stopped on the workpiece image Iw.

  Since the shape of the contact portion 261 is known, the position of the contact portion 261 can be specified with high accuracy using a known search technique. Therefore, even when the edge is rounded and the edge cannot be accurately detected on the two-dimensional workpiece image Iw as in the workpiece W in FIG. 4, the probe 26 and the workpiece W are positioned from the position of the contact portion 261. By specifying the coordinates of the contact position 13, the edge size that is difficult to detect on the image can be obtained with high accuracy.

  The contact position 13 is specified by specifying the position of the contact portion 261 from the work image Iw and offsetting it in the normal direction by a distance corresponding to the radius of the contact portion 261. Further, the position of the contour line 14 on the right side surface is obtained by fitting a predetermined geometric figure to the plurality of contact positions 13. On the other hand, the position of the contour line 14 on the left side is obtained by detecting an edge point from the edge extraction region 15 on the work image Iw and fitting a geometric figure to the detected plurality of edge points. Based on the position of the contour line 14 specified in this way, the distance D between the right side surface and the left side surface is calculated.

<Controller 3>
FIG. 5 is a block diagram showing a configuration example of the controller 3 of FIG. The controller 3 includes a control device 31 and a storage device 33, and the control device 31 and the storage device 33 are connected via a bus 32. The control device 31 includes an input receiving unit 311, a display control unit 312, an imaging control unit 313, an illumination control unit 314, and a measurement control unit 315. The main body 2 includes a camera 200 including imaging units 201 and 206 and a vertical driving unit 22, a stage 23 including a horizontal driving unit 24, a probe unit 260 including a switching driving unit 27, a display unit 21, a transmission illumination unit 25, and The reflection illumination unit 28 is used. The reflective illumination unit 28 includes a coaxial epi-illumination light source 209 and a ring illumination unit 211.

  The display control unit 312 displays a model image and setting information for dimension measurement on the display unit 21. The model image may be, for example, a master piece image obtained by photographing a master piece, or may be a CAD image made up of CAD data created by CAD (Computer Aided Design).

  When displaying the model image generated from the design data on the display unit 21, the display control unit 312 assumes that the image data obtained by imaging the workpiece W placed on the stage 23 from above is designed. The model image generated from the data is displayed. In this way, even the model image generated from the design data is displayed at the same angle as the work image picked up by the image pickup unit 201 or 206, thereby facilitating specification of the contact target position information. be able to.

  The input receiving unit 311 acquires a model image from the imaging unit 201 or 206 based on a user operation received by the input unit 4 and registers various measurement setting information for measuring dimensions in the storage device 33. I do.

  The imaging control unit 313 controls the imaging units 201 and 206 based on the measurement setting information registered in the storage device 33, and performs switching of imaging magnification and adjustment of imaging timing and exposure time. The illumination control unit 314 performs lighting control of the transmitted illumination unit 25, the coaxial incident illumination light source 209, the ring illumination unit 211, and the probe light source 263 based on the measurement setting information registered in the storage device 33. For example, when switching from image measurement to probe measurement, the illumination control unit 314 turns on the probe light source 263 while turning off the transmitted illumination unit 25, the coaxial incident illumination light source 209, and the ring illumination unit 211.

  The measurement control unit 315 controls the vertical drive unit 22, the horizontal drive unit 24, and the switching drive unit 27 based on the measurement setting information registered in the storage device 33, and acquires the work image Iw from the imaging unit 201 or 206. Measure the dimensions.

<Input reception unit 311>
FIG. 6 is a block diagram illustrating a configuration example of the input receiving unit 311 in FIG. The input receiving unit 311 includes an imaging and illumination condition specifying unit 341, an edge extraction region specifying unit 342, a contact position specifying unit 343, a measurement setting unit 344, a design value and tolerance specifying unit 345, and a feature amount information setting unit 346. The

  The imaging and illumination condition designating unit 341 designates imaging conditions such as imaging magnification, exposure time, and gain, and illumination conditions such as illumination type, brightness, and height of the ring illumination unit based on a user instruction. Registered as measurement setting information in the storage device 33.

  The edge extraction region designation unit 342 designates the edge extraction region on the model image as feature amount information, for example, a relative coordinate value with respect to the pattern image, based on the user's instruction, and stores it as edge extraction region information in the storage device 33. sign up.

  The contact position designation unit 343 accepts designation of contact target position information indicating a plurality of contact target positions on the side surface of the work W to be contacted by the probe 26 on the model image displayed on the display unit 21. That is, the contact position designating unit 343 sets the contact target position information for determining the probe operation for bringing the probe 26 into contact with a plurality of contact target positions to be contacted by the probe 26 with relative coordinates with respect to the feature amount information (pattern image). It is designated as a value and registered in the storage device 33. The contact target position information includes a contact target position, a scan operation start position, and a scan operation end position.

  The contact target position includes a relative position coordinate with respect to the pattern image (search data) registered on the model image, and a measurement height indicating the height of the side surface of the workpiece to which the probe 26 should contact. The measurement height is designated in advance by the user, for example.

  The measurement setting unit 344 extracts the edge of the workpiece W existing on the model image from the edge extraction region designated by the edge extraction region designation unit 342, and brings the probe 26 into contact with the contact target position, By imaging the probe 26, the contact position between the probe 26 and the workpiece W existing on the model image is specified, and based on these edges or contact positions, a contour line as a measurement reference from the model image, Identify the reference point. A measurement element (for example, a straight line, a circle, an arc, etc.) is specified based on the specified contour line or reference point. When the feature amount information is CAD data, the contour line and the reference point are specified directly without edge extraction.

  The measurement setting unit 344 selects an element to be measured from the measurement elements specified by the above-described processing based on a user instruction, and registers the selected element in the storage device 33 as measurement location information. The measurement element can also be specified based on an auxiliary line (point) newly created from the specified contour line or reference point. Examples of the auxiliary line (point) include an intersection of two contour lines and a circle center. The measurement setting unit 344 can specify the radius and diameter when the selected measurement element is a circle or an arc, and the distance between the straight lines when the two straight lines are selected as the measurement target.

  The design value and tolerance designation unit 345 designates the design value and tolerance for pass / fail judgment based on the user's instruction, and registers the design value and tolerance in the storage device 33 as measurement setting information.

  The feature amount information setting unit 346 sets feature amount information for specifying the position and orientation of the workpiece W from the workpiece image captured by the imaging unit 201 or 206 when performing measurement. That is, the feature amount information setting unit 346 sets feature amount information including search data for specifying the position and orientation of the workpiece W based on the model image based on the user's instruction, and measures the feature amount information in the storage device 33. Register as setting information. For example, the feature amount information is a pattern image (data) for normalized correlation search, and is set based on a master piece image obtained by photographing a master piece. The storage device 33 stores the pattern image set by the feature amount information setting unit 346 and the contact target position information specified by the contact position specifying unit 343 on the same coordinates.

  The pattern image may be registered by the user specifying a portion having many features on the model image, or the entire image may be automatically registered as the pattern image. In addition, a pattern image may be automatically registered by extracting a feature portion from a model image.

  By matching the registered pattern image and the work image obtained by imaging the inspection target work W, the position and orientation (coordinates) of the work W in the work image can be specified. For matching, a known matching technique such as normalized correlation search or geometric search can be used. Note that if the model image is a CAD image, the feature amount information can be specified based on the CAD data.

  As described above, according to the present embodiment, the contact target position information and the edge extraction region by the probe 26 are designated as relative coordinate values with respect to the pattern image (search data) registered on the model image. . The contact target position information includes a contact target position that is a target position for contacting the probe 26, a scan operation start position that is a position for starting a scan operation, a scan operation end position that is a position for ending the scan operation, and a work to be contacted Measurement height indicating the height of the side is included.

  A user obtains a workpiece image by placing the workpiece W to be inspected on the stage 23, and executes a matching process using a pattern image (search data). Extraction area can be specified automatically. The outline of the workpiece W is specified by sequentially bringing the probe 26 into contact with the side surface of the workpiece according to the specified contact target position. In addition, in order to specify a linear outline, coordinate information of two or more contact positions is required, and in order to specify a circular or arc-shaped outline, the coordinates of three or more contact positions are required. Information is needed. In addition, two or more contact positions are not necessarily required, and when it is desired to measure a specific point, the coordinate information of one contact position can be used for the measurement.

  The input accepting unit 311 accepts designation of a measurement element to be measured by the probe 26 on the model image displayed on the display unit 21. The model image being displayed on the display unit 21 is a work image obtained by capturing the work W for measurement setting. The storage device 33 stores in advance an arrangement rule that defines the relationship between the shape type or size of the measurement element that can be designated by the input reception unit 311 and the arrangement position of the contact target position of the probe 26. The arrangement rule is information for appropriately specifying the contact target position according to the shape type or size of the measurement element. The arrangement rule includes, for example, a table, a function, or an arithmetic expression that associates the shape type and size of the measurement element with the number of contact target positions.

  For example, when the shape type of the measurement element is a circle or an arc, the arrangement rule is determined so that three or more contact target positions are arranged at equal intervals in the circumferential direction of the circle or arc. In addition, when the shape type is a straight line, the arrangement rule is determined so that two or more contact target positions are arranged at equal intervals in the direction of the straight line.

  The measurement control unit 315 performs the contact target of the probe according to the position of the measurement element designated by the input receiving unit, the shape type or size of the measurement element, and the arrangement rule stored in the storage unit when performing measurement. The position is specified, and the horizontal drive unit is controlled so that the probe sequentially moves to the specified plurality of contact target positions.

  When an edge extraction region is set on the measurement element, the contact position designation unit 343 obtains a contour line by extracting an edge from the edge extraction region with respect to the model image being displayed, and obtains a plurality of positions as the positions on the contour line. A contact target position is designated, and a start position of a scanning operation for approaching the probe 26 is designated as a position separated from the contact target position in the normal direction of the contour line.

  The display unit 21 displays a symbol indicating the start position of the scan operation on the model image, and the contact position specifying unit 343 scans the probe 26 to approach the start position of the scan operation, the number of contact target positions on the contour line. A user operation for changing the direction and height information is received.

FIG. 7 is a diagram illustrating an example of an operation at the time of designating a contact position in the input receiving unit 311 in FIG. (A) in the figure shows a work W for registering the pattern image Ip and the target contact position information. In this work W, both outer sides of the protruding part w ₂ formed on the base member w ₁ have a curved shape, and the distance D between the side surfaces of the protruding part w ₂ is measured using the probe 26.

  The model image Im is a reflected image captured by reflected illumination, and a partial area including the workpiece W is registered as the pattern image Ip. There are three methods for associating the pattern image Ip with the contact target position information, for example, as shown in the following (b) to (d).

  (B) in the figure shows a case where the pattern image Ip and the contact target position are directly associated with each other. For example, by designating the start position and end position of the scanning operation for the pattern image Ip, the contact target position is automatically specified. The start position and the end position can be specified by moving the symbol Sm indicating the probe 26 and the arrow Y indicating the scanning direction by operating the mouse. Note that the start position and end position of the scanning operation may be automatically determined by designating the contact target position. In this way, the contact target position coordinates are stored relative to the pattern image (search data) by directly associating the pattern image Ip with the contact target position.

  (C) in the drawing shows a case where the contour line L specified by extracting an edge from the edge extraction region R and the contact target position are associated with each other. An edge point is extracted from the edge extraction region R designated on the pattern image Ip, and a contour line L to be fitted to the extracted edge point sequence is specified. By designating the contact target position with respect to the contour line L, the pattern image Ip and the contact target position are indirectly associated. The position coordinates of the edge extraction region R on the workpiece image input at the time of inspection are automatically specified by matching the workpiece image with the pattern image (search data). An edge point sequence in the edge extraction region R whose position has been specified is extracted, and a contact target position is set at a predetermined position with respect to the contour line L specified from the edge point sequence. For example, when the scanning direction is set to a direction approaching from a position that is a predetermined distance away from the contour line L in the normal direction, the approach can be stably approached along the normal line of the contour line L, so that the measurement is stable. To do.

  (D) in the figure shows a case where the edge extraction region R and the contact target position are associated with each other. By designating the contact target position for the edge extraction region R designated on the pattern image Ip, the pattern image Ip and the contact target position are indirectly associated. The position coordinates of the edge extraction region R are specified by the matching process described above, and at the same time, the target contact position coordinates are specified.

  FIG. 8 is a diagram illustrating an example of an operation at the time of pattern image registration in the input reception unit 311 in FIG. 5. A model image Im when the workpiece W illustrated in FIG. It is shown. A part of the model image Im is registered as a pattern image Ip for search. In this way, a transmitted image captured with transmitted illumination is used as the search pattern image Ip, while a reflected image captured with reflected illumination can be used to specify the contact target position.

  In general, a transmitted image captured with transmitted illumination provides a clear edge, and changes in the image due to changes in the surrounding environment are small. Therefore, while registering a pattern image based on a transmission image captured with transmission illumination, it is captured with reflection illumination in order to measure the dimension of the inner contour existing in a non-penetrating workpiece shape that cannot be obtained with transmission illumination. The contact target position can be designated by the probe 26 based on the reflected image. In this way, the illumination condition for registering the pattern image can be different from the illumination condition for registering the contact target position and the edge extraction region. Further, in order to make the illumination condition at the time of continuous measurement the same as the illumination condition at the time of setting, the illumination condition at the time of setting is registered as measurement setting information.

  As described above, the target contact position is specified directly or indirectly by matching the pattern image (search data) registered on the model image Im at the time of setting with the work image input at the time of inspection. The When the position to be scanned is specified by the probe 26, the operation plan of the probe 26 is determined, and the measurement control unit 315 controls the operation of the probe 26.

  FIG. 9 is a diagram showing an example of the operation at the time of designating the contact position in the input reception unit 311 in FIG. 5, and shows a table in which the shape type and the number of scan paths are associated with each other. (A) in the figure shows a table when the number of divisions is fixed. This table is an arrangement reference that associates the shape type of the measurement target with the number of scan paths, and the number of scan paths and the number of divisions are defined for three shape types (straight line, circle, and arc).

  Specifically, if the shape type is a straight line, the number of divisions is 3, and two scan paths are arranged so as to divide the straight line into three equal parts. If the shape type is a circle, the number of divisions is 3, and three scan paths are arranged so that the circumference is equally divided into three. If the shape type is an arc, the number of divisions is 4, and three scan paths are arranged to divide the arc into four equal parts.

  (B) in the figure shows a table when the number of divisions is variable according to the size of the measurement target. This table is an arrangement reference that associates the shape type and size of the measurement target with the number of scan paths, and the number of scan paths is defined for three shape types (straight line, circle, and arc).

  Specifically, when the shape type is a straight line and the length of the contour line L is less than the threshold value TH, the number of divisions is 3, and two scan paths are arranged so as to divide the straight line into three equal parts. The On the other hand, if the length of the contour line L is equal to or greater than the threshold value TH, the number of divisions is 4, and three scan paths are arranged to divide the straight line into four equal parts. When the shape type is a circle and the length of the contour line L is less than the threshold value TH, the number of divisions is 3, and three scan paths are arranged so as to divide the circumference into three equal parts. On the other hand, if the length of the contour line L is equal to or greater than the threshold value TH, the number of divisions is 4, and four scan paths are arranged so as to divide the circumference into four equal parts. When the shape type is an arc, if the length of the contour line L is less than the threshold TH, the number of divisions is 4, and three scan paths are arranged so as to divide the arc into four equal parts. On the other hand, if the length of the contour line L is equal to or greater than the threshold value TH, the number of divisions is 5, and four scan paths are arranged so as to divide the arc into five equal parts.

  FIG. 10 is a diagram illustrating an example of the operation at the time of designating the contact position in the input receiving unit 311 in FIG. 5, and shows a case where the number of scan paths differs according to the length of the contour line L. In the figure, (a) shows a case where the shape type is a straight line, and (b) shows a case where the shape type is a circle.

  If the edge extraction region R is specified as a measurement target region on the model image Im by the user, the contact target position is specified for the contour line L specified by extracting the edge from the edge extraction region R. For example, the contact target position is designated at regular intervals from the end point of the contour line L. If the shape type of the contour line L is a straight line, two or more contact target positions are specified, and if the shape type of the contour line L is a circle or an arc, three or more contact target positions are specified. In this case, the number of contact target positions designated on the contour line L varies depending on the length of the contour line L. Note that the contour line L may be specified directly by a mouse operation or the like.

  Further, as shown in the illustrated scan path, n or (n-1) scan paths for equally dividing the contour line L may be specified by designating a division number n of 3 or more. . Specifically, as shown in FIG. 10A, if the shape type of the contour line L is a straight line, the number of divisions is set to 3 when the length of the contour line L is less than a certain value, and the contour line L Two scan paths that equally divide are designated. On the other hand, when the length of the contour line L is equal to or greater than a certain value, the number of divisions is set to 4, and three scan paths for equally dividing the contour line L are designated.

  Further, as shown in FIG. 10B, if the shape type is a circle, the number of divisions is set to 3 when the radius is less than a certain value, and three scan paths for equally dividing the contour line L are designated. The On the other hand, when the radius is equal to or larger than a certain value, the number of divisions is set to 4, and four scan paths for equally dividing the contour line L are designated.

  The start position of the scan path is designated as a position that is separated from the contact target position by a certain distance in the direction perpendicular to the contour line L. The end position of the scan path is designated as a position on the opposite side of the start position across the contour line L. Further, based on the luminance difference between both sides of the edge extracted from the model image Im, the scanning direction for bringing the probe 26 close to the side surface of the workpiece W is determined. The method for determining the start position and end position of the scan path is not limited to the above method. The start position and the end position of the scan path may be determined relative to the contact target position.

<Measurement control unit 315>
FIG. 11 is a block diagram illustrating a configuration example of the measurement control unit 315 in FIG. The measurement control unit 315 includes a search processing unit 351, an edge extraction region specifying unit 352, an edge extraction processing unit 353, a scan operation determining unit 354, a scan operation control unit 355, a probe detection unit 356, a contact position specifying unit 357, an outline The calculation unit 358 and the dimension calculation unit 359 are configured.

  The search processing unit 351 acquires a work image from the imaging unit 201 or 206 and specifies the position and orientation of the work W based on the feature amount information in the storage device 33. The position and orientation are specified by pattern search. The search processing unit 351 acquires a workpiece image generated in a state where the probe 26 is at the retracted position outside the imaging field of view, and specifies the position and orientation of the workpiece W from the workpiece image.

  The edge extraction region specifying unit 352 specifies an edge extraction region on the workpiece image based on the position and posture of the workpiece W specified by the search processing unit 351 and the edge extraction region information. The edge extraction processing unit 353 extracts edge points from the edge extraction region specified by the edge extraction region specifying unit 352.

  The scanning operation determination unit 354 specifies the position of the contour line by fitting a geometric figure previously specified as a shape type to the plurality of edge points extracted by the edge extraction processing unit 353, and sets the position as the contact target position information. Based on this, the scan operation is determined by specifying the start position and the scan direction.

  The scan operation control unit 355 controls the vertical drive unit 22, the horizontal drive unit 24, and the switching drive unit 27 of the main body 2 according to the scan operation determined by the scan operation determination unit 354. For example, the scan operation control unit 355 controls the switching drive unit 27 to switch the probe 26 from the retracted position to the measurement position, and then moves the horizontal drive unit 24 so that the probe 26 sequentially moves to a plurality of contact target positions. Control.

  The probe detection unit 356 detects that the probe 26 has contacted the side surface of the workpiece W. For example, when a workpiece image is repeatedly acquired from the imaging unit 201 or 206 and the position of the probe 26 moving on the scan path on the workpiece image changes by a certain threshold value within a certain time, the probe 26 is placed on the side surface of the workpiece W. Judged to have touched. A sensor for detecting physical contact may be provided on the probe 26.

  When it is detected that the probe 26 is in contact with the side surface of the workpiece W, the contact position specifying unit 357 acquires a workpiece image in which the probe 26 in contact with the side surface of the workpiece W is photographed, The contact position is specified from the position of the probe 26. Based on the position of the probe 26 on the workpiece image and the relative position of the imaging field of view with respect to the stage 23, a plurality of contact positions where the probe 26 has contacted the workpiece W are specified.

  The relative position of the imaging field of view with respect to the stage 23 is input from the horizontal drive unit 24. From the position coordinates of the imaging field of view (relative position of the camera 200 or the stage 23) in the global coordinate system input from the horizontal drive unit 24 and the coordinates of each contact position in the local coordinate system within the imaging field of view, each contact position Is required.

  In the present embodiment, the camera 200 and the probe 26 do not operate in the XY direction, and the stage 23 moves in the XY direction so that the probe 26 and the side surface of the workpiece W are brought into contact with each other. Therefore, in a state where the probe 26 is not in contact with the workpiece W, the probe 26 is always located at the center in the imaging field. The present invention is not limited to this embodiment, and the camera side may move with the probe 26, or the probe 26 may move within the imaging field of view.

  The contour calculation unit 358 fits the geometric figure to the plurality of edge points extracted by the edge extraction processing unit 353 or the plurality of contact positions specified by the contact position specifying unit 357, thereby generating a contour line. Specify the position of.

  The dimension calculation unit 359 obtains the dimension of the workpiece W based on the position of the contour line specified by the contour line calculation unit 358 and displays the measurement result on the display unit 21. In the dimension calculation unit 359, the dimension of the workpiece W is determined using one or both of the contour line specified by extracting the edge from the edge extraction region and the contour line specified by the probe 26 contacting. Desired.

  For example, the dimension can be obtained by combining the contour line specified by edge extraction and the contour line specified by contact of the probe 26. By adopting such a configuration, the contour line of the measurement point where the edge cannot be accurately extracted is specified by contacting the probe 26, and the contour line of the measurement point where the edge can be accurately extracted is specified and dimensioned by edge extraction. Measurements can be made. That is, it is possible to reduce the time required for measuring the dimension of the portion that can be measured with the image by measuring with the image.

  Steps S101 to S107 in FIG. 12 are flowcharts showing an example of the operation at the time of measurement setting in the controller 3 in FIG. First, when one of the measurement methods of image measurement or probe measurement is selected by the user (step S101), the controller 3 sets measurement elements according to the selected measurement method (steps S102 to S104).

13 and 14 are diagrams showing an example of an operation at the time of measurement setting in the image measurement apparatus 1 of FIG. 13A shows the workpiece W to be registered, and FIG. 13B shows the edge extraction region R designated on the pattern image Ip and the symbol Sm indicating the start position of the scanning operation. Yes. The workpiece W includes a cylindrical projecting portion w ₂ is formed on the base member w _1, the periphery into three holes w ₃ of the base member w ₁ is formed.

The pattern image Ip is composed of a captured image obtained by capturing such a workpiece W as a subject. As the measurement location, the distance between the left and right side surfaces of the base member w ₁ , the distance between the front and rear side surfaces, the distance between the two through holes w ₃ , and the inner diameter of the protruding portion w ₂ are specified. The distance between the left and right side surfaces of the base member w ₁ and the distance between the two through holes w ₃ are measured by extracting an edge from the edge extraction region R specified for the contour line of the workpiece W. On the other hand, the distance between the front and back side surfaces of the base member w ₁ and the inner diameter of the protrusion w ₂ are measured by bringing the probe 26 into contact therewith.

  FIG. 14 shows a setting screen 100 displayed on the display unit 21 when the measurement setting information is designated. The setting screen 100 is an editing screen for measurement setting information, and includes a display column 110 for displaying a model image and a menu column 111 for selecting a dimension type.

  The model image being displayed in the display column 110 is a captured image obtained by capturing the work W illustrated in FIG. 12 as a subject. By operating the magnification button 131 or 132, either the low magnification for wide field measurement or the high magnification for high accuracy measurement can be designated as the imaging magnification. Further, if the stage adjustment button 133 is operated, the position in the X direction and the position in the Y direction of the stage 23 can be adjusted. Further, if the Z adjustment button 134 is operated, the position of the measurement unit 20 in the Z direction can be adjusted. By operating the illumination button 135, the illumination type can be designated. Illumination types include transmitted illumination, ring illumination, and coaxial epi-illumination.

  The dimension types in the menu column 111 include distance measurement and angle measurement. Distance measurement includes distance measurement between two straight lines, distance measurement between straight lines and points, distance measurement between two points, distance measurement between two circles, distance measurement between circles and straight lines, circles There is a distance measurement between each point, a circle diameter measurement and an arc radius measurement.

  In the setting of the image measurement element in step S103, the measurement setting information is specified for the measurement element for performing dimension measurement by edge extraction. On the other hand, in the setting of the probe measurement element in step S104, the measurement setting information is designated for the measurement element for measuring the dimension by bringing the probe 26 into contact. The processing contents of steps S103 and S104 will be described in detail with reference to FIGS. The controller 3 repeats the processing procedure from step S101 to S104 for all measurement elements on the model image until the setting is completed (step S105).

  Next, the controller 3 designates design values and tolerances (step S106). In this step, the dimension value calculated from the model image is displayed in association with the outline of the measurement element, and if the dimension value on the model image is selected by the user, a design value or tolerance is newly designated, or Can be changed.

  FIG. 15 shows a tolerance setting screen 101 when design values and tolerances are designated. The tolerance setting screen 101 is a design value and tolerance editing screen, and is provided with a display column 110 for displaying a model image and an input column 112 for designating the design value and the upper limit value and the lower limit value of the tolerance. ing. In the model image being displayed in the display column 110, a dimension line and an identification number are displayed in association with the measurement location.

  In this input column 112, design values and upper and lower tolerance limits are displayed for a plurality of measurement locations registered as measurement setting information. If a measurement location is selected, the design value, the upper limit of tolerance or A lower limit value can be newly designated or changed.

  Next, the controller 3 registers feature amount information (step S107). In this step, the pattern image (search data) for specifying the position and orientation of the workpiece W is converted into a model image together with the relative positional relationship between the pattern image and the edge extraction region specified by the setting of each measurement element. Registered.

  FIG. 16 shows a feature amount setting screen 102 when designating feature amount information. The feature amount setting screen 102 is an edit screen for registering a pattern image as feature amount information, and includes a display column 110 for displaying a model image, and an input column 114 for specifying a registration target region and a search condition. Is provided. In the model image displayed in the display column 110, a frame 113 indicating the outer edge of the registration target area is displayed.

  As the search condition, a search range for limiting the scan range in the rotation direction and the number of workpieces W that match the pattern image can be specified. When the registration button 115 is operated, the model image being displayed is registered as a pattern image for search.

  Steps S201 to S209 in FIG. 17 are flowcharts showing an example of detailed operations for step S103 (setting of image measurement elements) in FIG. 12, and the operations of the controller 3 are shown. First, the controller 3 designates shooting conditions to be described later (step S201), acquires a shot image obtained by shooting a master piece placed on the stage 23, and displays it as a model image (step S202).

  Next, the shape type of the measurement element is selected by the user (step S203), and the edge extraction region is specified by the user in association with the shape type (step S204). The controller 3 extracts a plurality of edge points from the designated edge extraction region (step S205), and fits a geometric figure corresponding to the selected shape type to these edge points to thereby determine the position of the contour line. Is determined (step S206).

  Next, the controller 3 calculates the dimension of the measurement location based on the position of the contour line, and displays the dimension value of the measurement result on the model image in association with the measurement element (steps S207 and S208). The controller repeats the processing procedure from steps S203 to S208 for all measurement elements on the model image until the setting is completed (step S209).

  FIG. 18 is a diagram illustrating an example of an operation when setting an image measurement element in the image measurement apparatus 1 of FIG. In the figure, (a) shows an edge extraction region 116 designated on the model image, and (b) shows an outline 117 specified by extracting an edge from the edge extraction region 116. Yes.

  If the position of the start point and end point of the measurement element is specified for the model image displayed in the display field 110 of the setting screen 100, a rectangular area including a straight line connecting the start point and end point is automatically specified as the edge extraction area 116. The edge point scan direction is displayed on the model image in association with the measurement element. When the registration of the edge extraction region 116 is completed, the contour 117 and the dimension value specified by extracting the edge from the edge extraction region 116 are displayed on the model image.

  Steps S301 to S315 in FIG. 19 are flowcharts showing an example of detailed operation for step S104 (setting of probe measurement elements) in FIG. 12, and the operation of the controller 3 is shown. The processing procedure from step S301 to step S306 is the same as the processing procedure from step S201 to step S206 in FIG.

  Next, the controller 3 designates contact target position information (step S307). The contact target position information, that is, the contact target position and the scan path are automatically specified based on the shape type and size of the measurement element. Also, the designated scan path is displayed superimposed on the model image (step S308).

  FIG. 20 is a diagram showing an example of the operation when setting the probe measurement element in the image measurement apparatus 1 of FIG. Since the probe measurement is performed by imaging the probe 26 with the camera 200, where the probe 26 should be brought into contact with the work W or how the approach is made to the side surface of the work W. It is difficult for the user to determine whether or not. In the image measurement apparatus 1 according to the present embodiment, the contact target position is automatically determined simply by designating the edge extraction region as the measurement target region on the model image.

  (A) in the figure shows an edge extraction region 118 designated on the model image Im. If three points are specified on the circumference of the measurement element for the model image Im displayed in the display field 110 of the setting screen 100, an annular area including these points is automatically set as the edge extraction area 118. Designated and displayed on the model image Im.

  (B) in the figure shows a contour line 119 identified by extracting an edge from the edge extraction region 118 and a symbol 120 indicating the start position of the scanning operation. When the registration of the edge extraction area 118 is completed, the edge is extracted from the edge extraction area 118 and the position of the contour line 119 is specified. The contact target position is specified for the contour line 119, and a symbol 120 indicating the start position of the scanning operation is displayed in association with the contour line 119. In this example, three scan paths are arranged along the contour line 119 at equal intervals.

  The symbol 120 and the workpiece W on the setting screen 100 are similar to the actual contact portion 261 and the workpiece W. Accordingly, the user can accurately grasp the positional relationship between the contact portion 261 and the workpiece W on the setting screen 100, and whether or not the contact portion 261 interferes with the workpiece W when the probe 26 is operated. Can be confirmed. Further, when there is a high possibility that the contact portion 261 and the workpiece W interfere with each other, an error may be displayed on the setting screen 100 to notify the user.

  (C) in the figure shows the contour line 121 specified by contacting the probe 26 and the dimension value displayed in association with the contour line 121. When the registration of the contact target position is completed, the model image in the setting screen 100 displays the contour line 121 specified by bringing the probe 26 into contact with the side surface of the workpiece W and is obtained from the contour line 121. Dimension values are displayed in association with the contour line 121.

  Next, the controller 3 inquires of the user whether or not to adjust the scan path (step S309), and if the user instructs to adjust the scan path, the controller 3 adjusts the target contact position (step S310).

  21 and 22 are diagrams illustrating an example of the operation when setting the probe measurement element in the image measurement apparatus 1 of FIG. FIG. 21A shows a case where the contact target position designated with respect to the contour line 119 on the model image Im is adjusted, and FIG. 21B shows a case where the scan direction is changed. (C) shows a case where the number of scan paths is changed.

  The contact target position designated for the contour line 119 on the model image Im can be adjusted by moving the symbol 120 indicating the start position of the scanning operation by a mouse operation or the like. For example, by moving the symbol 120 in the radial direction of the contour line 119, the start position of the scanning operation can be moved away from the contour line 119. Further, by operating the setting screen 100, the scan direction can be reversed or a scan path can be added.

  22A shows the workpiece W to be registered, FIG. 22B shows the contact target position designated on the model image Im, and FIG. 22C shows the symbol displayed as an error. 120 is shown. Two scan paths are designated for the contour line 119 corresponding to the right side surface of the workpiece W. The contact target position can be changed by moving the symbol 120 indicating the start position of the scanning operation by a mouse operation or the like.

  As the start position of the scanning operation is closer to the outline 119 of the measurement location, the measurement time can be shortened. However, if the start position of the scanning operation is too close to the outline 119 of the measurement location, the probe 26 may interfere with the work W when the probe 26 is moved to the start position due to dimensional variations of the work W. That is, when the right outline 119 is a measurement target, if the scan start position is too close to the right outline 119, the probe 26 interferes with the workpiece W due to dimensional variations of the workpiece W during continuous measurement.

  As described above, when the contact target position designated on the model image Im is close to the contour line 119 to be measured, the contact target position can be adjusted so as to be away from the contour line 119. That is, the start position of the scanning operation can be adjusted so as to be away from the right outline 119.

  On the other hand, if the scan start position is too close to the left outline 119, the probe 26 interferes with the left side surface of the workpiece W. In this way, if the scan start position is designated at a position overlapping with a contour line different from the contour line 119 to be measured, the symbol 120 is displayed as an error. Therefore, the user can easily adjust the contact target position by confirming the model image Im.

  FIG. 23 is a diagram showing an example of the operation when setting the probe measurement element in the image measurement apparatus 1 of FIG. (A) in the figure shows a workpiece W to be registered, and (b) shows a case where the height position of the scanning operation is adjusted on the model image Im. The workpiece W has a step in the height direction, and a horizontal distance D between the lower right side surface and the upper right side surface is measured using the probe 26.

Since the lower right side surface and the upper right side surface of the work W have different vertical positions, it is necessary to appropriately specify the measurement height of the scanning operation. That is, the measurement height h ₂ for measuring the right side surface of the upper, it is necessary to specify a position higher than the measured height h ₁ for measuring the right side surface of the lower. Such height information may be specified by actually moving the probe 26 or numerically.

  When the measurement height is changed, the vertical drive unit 22 can be controlled to move the probe 26 to the changed measurement height, thereby actually confirming the height relationship between the workpiece W and the contact part 261. be able to.

  Next, the controller 3 starts a scanning operation, acquires a captured image obtained by capturing the probe 26 in contact with the side surface of the master piece, and specifies the position of the contact point based on the captured image (step S311). ). Then, the controller 3 determines the position of the contour line from the positions of two or more contact points (step S312).

  The controller 3 calculates the dimension of the measurement location based on the position of the contour line, and displays the dimension value of the measurement result on the model image in association with the measurement element (steps S313 and S314). The controller repeats the processing procedure from step S303 to S314 for all measurement elements on the model image until the setting is completed (step S315).

  FIG. 24 is a diagram showing an example of the operation when setting the probe measurement element in the image measurement apparatus 1 of FIG. In the figure, (a) shows the case of the first scan mode, and (b) shows the second scan mode. The first scan mode and the second scan mode are moving methods when the probe 26 moves between the contact target positions relative to the stage 23, and designates either the first scan mode or the second scan mode. can do.

  In the first scan mode, the probe 26 is switched from the measurement height to the reference height for each movement between the contact target positions. When there is an obstacle such as a step between two adjacent contact target positions, interference with the workpiece W can be reliably prevented by selecting the first scan mode.

  On the other hand, in the second scan mode, the probe 26 moves between the contact target positions relative to the stage 23 without switching to the reference height. Specifically, when a plurality of contact target positions are specified for one measurement element, the probe 26 is moved between the contact target positions relative to the stage 23 without switching to the reference height. Let However, when the probe 26 is moved relative to the stage 23 between two different measurement elements, the probe 26 may be moved without switching to the reference height, but the probe 26 is moved from the measurement height. It is desirable to switch to the reference height. The measurement time can be shortened by moving the probe 26 along the contour line at the same height relative to the stage 23.

  Steps S401 to S404 in FIG. 25 are flowcharts showing an example of detailed operations for step S107 (registration of feature amount information) in FIG. 12, and the operations of the controller 3 are shown. First, after designating shooting conditions (step S401), the controller 3 acquires a model image in which a master piece is shot and designates a registration target area (step S402).

  Next, the controller 3 designates a search condition for performing a pattern search using the pattern image (step S403). The controller 3 repeats the processing procedure from step S401 to step S403 until all the settings related to the registration of the feature amount information are completed (step S404). If all the settings are completed, the pattern obtained from the model image is obtained. Images and search conditions are stored as feature information.

  Steps S501 to S508 in FIG. 26 are flowcharts showing an example of detailed operations for step S201 in FIG. 17, step S301 in FIG. 19 and step S401 in FIG. 25 (designation of shooting conditions). It is shown. First, the controller 3 confirms the position of the probe 26, and if it is not the retracted position, it switches to the retracted position by controlling the switching drive unit 27 of the measurement unit 20 (steps S501 and S502).

  Next, the controller 3 controls the horizontal drive unit 24 to adjust the position in the X direction and the position in the Y direction of the stage 23 in the horizontal plane (step S503). Next, in order to adjust the focus position, the controller 3 controls the vertical drive unit 22 to adjust the position of the measurement unit 20 in the Z direction (step S504).

  Next, the controller 3 designates illumination conditions, imaging conditions, and imaging magnification (steps S505 to S507). Illumination conditions include illumination type, lighting state, brightness, and position of the ring illumination unit 211 in the Z direction. Imaging conditions include exposure time, gain, and imaging range.

  The controller 3 repeats the processing procedure from step S503 to step S507 until all the settings relating to the specification of the imaging conditions are completed (step S508). If all the settings are completed, the imaging conditions are stored as measurement setting information. To do.

  Steps S601 to S617 in FIG. 27 and FIG. 28 are flowcharts showing an example of the operation at the time of continuous measurement in the controller 3 in FIG. First, the controller 3 reads the measurement setting information (step S601), and designates the imaging condition based on the measurement setting information (step S602). Next, the controller 3 captures the workpiece W placed on the stage 23 under the above-described photographing conditions to obtain a workpiece image (step S603), and the position and orientation of the workpiece W by pattern search using feature amount information. Is specified (steps S604 and S605).

  Next, the controller 3 specifies the position of the edge extraction region on the work image based on the position and orientation of the work W specified by the pattern search (step S606). The controller 3 extracts a plurality of edge points from the specified edge extraction region (step S607), and specifies the position of the contour line by fitting a geometric figure to these edge points (step S608).

  Next, if the image measurement element is registered as measurement setting information (step S609), the controller 3 calculates the dimension of the measurement location based on the position of the specified contour line (step S610), and the measurement element The dimension value of the measurement result is displayed on the work image in association with (Step S611).

  Next, if the probe measurement element is registered as measurement setting information (step S612), the controller 3 controls the switching drive unit 27 of the measurement unit 20 to switch the probe 26 from the retracted position to the measurement position. The vertical drive unit 22 is controlled to switch to the reference height (step S613). The controller 3 specifies the scan start position based on the position of the contour line extracted and specified from the edge extraction region (step S614), and performs the scan operation (step S615).

  Next, the controller 3 obtains a photographed image obtained by photographing the probe 26 in contact with the side surface of the workpiece W, obtains the position of the contact point based on the photographed image, identifies the position of the contour line, and performs measurement. The dimension of the location is calculated (step S616). Then, the controller 3 displays the dimension value of the measurement result in association with the measurement element on the work image (step S617).

  When the contact target position is directly associated with the pattern image, the contact target position is directly specified from the position and posture of the workpiece W specified by the pattern search. Further, when the contact target position is associated with the edge extraction area, the position of the edge extraction area on the work image is specified based on the position and posture of the work W specified by the pattern search, thereby A location is identified.

  FIGS. 29 to 31 are diagrams showing an example of the operation at the time of continuous measurement in the image measuring apparatus 1 of FIG. 29 (b) to (d), FIG. 30 (a) to (d), and FIG. 31, two work images Iw having different positions and postures of the work W are shown as case 1 and case 2, respectively. Has been. 29A shows a pattern image Ip registered as search data, and FIG. 29B shows a work image Iw captured for pattern search. Both the pattern image Ip and the work image Iw are transmitted images by transmitted illumination. By matching the workpiece image Iw with the pattern image Ip, the position and orientation of the workpiece W are specified.

  FIG. 29 (c) shows a work image Iw imaged for edge extraction. This work image Iw is a reflected image by reflected illumination, and an edge extraction region is specified based on the position and posture of the work W specified by the pattern search.

  FIG. 29D shows a plurality of edge extraction regions R specified on the work image Iw shown in FIG. The position coordinates of the edge extraction region R are specified based on the position and orientation of the workpiece W and the relative position information registered as the edge extraction region information.

FIG. 30A shows a plurality of contour lines L ₁ and L ₂ specified by extracting an edge from the edge extraction region R. Contour line L _1, the measurement element is a contour line in a case that is registered as the image measuring elements. On the other hand, the contour line L _2, when the measuring element is registered as a probe measuring element, a provisional contour used to identify the contact target position, positional accuracy is low.

In (b) of FIG. 30, a plurality of contact target position specified with respect to the contour line L ₂ on the work image Iw is shown. Contact target position, based on the relative position information registered as the position and the contact target position information of contour L _2, are specified.

FIG. 30C shows a plurality of contact positions P identified by bringing the probe 26 into contact therewith. The contact position P is specified based on the workpiece image Iw acquired in a state where the probe 26 is in contact with the side surface of the workpiece W and the position of the stage 23. In (d) of FIG. 30 is a contour line L ₃ identified by fitting a geometric figures into a plurality of the contact position P is shown.

FIG. 31 shows a workpiece image Iw in which the result of the quality determination of the workpiece W is displayed in association with the measurement location. Based on the contour line L ₃ identified by the identifying contour line L ₁ and the probe operation by the edge extraction, the dimension values of the measurement point is determined. Further, the quality of the workpiece W is determined by comparing the obtained dimension value with the design value and comparing the error with respect to the design value with the tolerance. The result of the pass / fail judgment is displayed on the work image Iw in association with the measurement location.

  In the work image Iw shown on the left side of FIG. 31, all measurement locations are OK, and the work W is determined to be a non-defective product. On the other hand, in the work image Iw shown on the right side of FIG. 31, one of the measurement points registered as the image measurement element is NG determination, and the work W is determined to be a defective product.

  Steps S701 to S712 in FIG. 32 are flowcharts showing an example of detailed operation for step S615 (scan operation) in FIG. 28, and show the operation of the controller 3. First, the controller 3 controls the horizontal drive unit 24 to move the probe 26 relative to the stage 23 at a reference height to a position corresponding to the start position of the scan path (step S701), and then vertically. The drive unit 22 is controlled to move the probe 26 to the measurement height (step S702).

  Next, the controller 3 controls the horizontal driving unit 24 to move the probe 26 relative to the stage 23 in the scanning direction (step S703). If contact is detected, the probe 26 on the workpiece image is detected. And the position of the stage 23, the contact position is calculated (steps S704 and S705). The probe 26 is controlled so as to approach along the normal line of the contour line on the workpiece image. The controller 3 repeats the processing procedure from step S701 to step S705 until the measurement is completed for all contact target positions. When the measurement is completed for all contact target positions, the probe 26 is moved to the reference height. This process ends (steps S706 and S707).

  If the first scan mode is designated, the controller 3 moves the probe 26 to the reference height every time measurement is completed for one contact target position (steps S706, S711, S712).

  The controller 3 determines that an error has occurred if the probe 26 reaches the end position without detecting contact, and moves the probe to the reference height to output an error (steps S704 and S708). ~ S710).

  According to the present embodiment, since the position and orientation of the workpiece W are specified from the workpiece image based on the pattern image, the dimension measurement using the probe 26 is performed only by placing the workpiece W on the stage 23. be able to. In addition, since the contact target position to which the probe 26 should contact is specified based on the contact target position information, a plurality of contact target positions with respect to the workpiece W can be simply specified by first specifying a relative position with respect to the pattern image. And the probe 26 can be moved sequentially.

  Further, since the workpiece image for specifying the position and orientation of the workpiece W is generated in a state where the probe 26 is in the retracted position, the probe 26 is imaged in an overlapping manner with the workpiece W or is imaged in the vicinity of the workpiece W. Can be prevented.

  Further, according to the present embodiment, a plurality of contact target positions on the side surface of the workpiece to be contacted by the probe 26 are specified according to the position of the measurement element, the shape type or size of the measurement element, and the arrangement rule. By simply designating the measurement element, the plurality of contact target positions can be automatically identified and the scanning operation by the probe 26 can be determined.

  In the present embodiment, an example in which the horizontal driving unit 24 moves the stage 23 in the X direction and the Y direction has been described, but the present invention does not limit the configuration of the horizontal driving unit 24 to this. . For example, the horizontal drive unit 24 may be configured to move the probe 26 or the measurement unit 20 in the X direction and the Y direction. Alternatively, the horizontal driving unit 24 may move the stage 23 in the X direction and move the probe 26 or the measurement unit 20 in the Y direction.

  In the present embodiment, an example in which the vertical drive unit 22 moves the measurement unit 20 in the Z direction has been described. However, the present invention does not limit the configuration of the vertical drive unit 22 to this. For example, the vertical drive unit 22 may be configured to move the stage 23 in the Z direction.

  In the present embodiment, an example in which the scan direction of the scan path is designated based on the luminance difference between both sides of the edge has been described. However, the present invention does not limit the scan direction designation method to this. Absent. For example, the configuration may be such that height information in the vicinity of the measurement location is acquired using the focus position of the imaging unit 201 or 206, and the scan direction is designated based on this height information. The scan direction may be configured so that a predetermined direction is designated by default.

  In this embodiment, an example in which the measurement height of the contact target position is specified by the user has been described. However, the present invention automatically uses the focus position of the imaging unit 201 or 206 to measure the measurement height. The configuration may be specified as desired.

  In the present embodiment, an example in which it is detected that the probe 26 has contacted the side surface of the workpiece W based on the workpiece image has been described. However, the present invention limits the contact detection method to this. It is not a thing. For example, it may be configured to detect that the probe 26 is in contact with the side surface of the workpiece W using a sensor that detects pressure or vibration.

  Further, in the present embodiment, an example in which the probe 26 is attached to the housing of the measurement unit 20 has been described. However, in the present invention, the probe 26 is within a measurement region in the imaging field of the imaging unit 201 or 206. The present invention can also be applied to those that are movable in the horizontal direction.

  In the present embodiment, the image measuring apparatus 1 including the self-luminous probe 26 that transmits the guide light from the probe light source 263 through the metal tube 262 has been described. The configuration is not limited to this. For example, the probe may not emit guide light.

<Adherent detection>
The measurement control unit 315 functions as a measurement unit that measures the position of the side surface of the workpiece W using the image generated by the imaging unit 201 when the contact unit 261 contacts the side surface of the workpiece W. Therefore, if foreign matter (attachment) such as oil or dust adheres to the contact portion 261, an error occurs in the measurement result of the position of the side surface of the workpiece W. Therefore, the measurement control unit 315 further includes a shape determination unit that determines whether the shape of the contact part 261 in the image of the contact part 261 generated by the imaging unit 201 is a predetermined shape. The display unit 21 functions as an output unit that outputs the determination result of the shape determination unit. Note that the imaging unit 206 may be used instead of the imaging unit 201. Since the imaging unit 206 is an imaging device having a higher imaging magnification than the imaging unit 201, the contact unit 261 can be accurately photographed even with a very small contact unit 261.

  FIG. 35A shows an example of an image Ic1 of the contact portion 261 generated by the imaging unit 201 when no deposit is attached to the contact portion 261. Since the contact portion 261 is lit, the outer periphery of the contact portion 261 is white in the image Ic1. FIG. 35B shows an edge 3501 of the contact portion 261 extracted from the image Ic1. Since the contact portion 261 is a sphere, the portion of the contact portion 261 in the image Ic1 has a horizontal cross-sectional shape. That is, the edge 3501 is a circle with a radius r. FIG. 35 (c) shows a least square approximation circle 3502 obtained from the edge 3501 of the contact portion 261. The radius r of the least square approximation circle 3502 is also a designed value.

  FIG. 35D shows an example of an image Ic2 of the contact part 261 generated by the imaging part 201 when the dust 3500 adheres to the contact part 261. The garbage 3500 is exaggerated for convenience of explanation. FIG. 35B shows an edge 3511 of the contact portion 261 extracted from the image Ic2. The distance from the center to the outer peripheral portion (edge) to which the dust 3500 is attached is a distance r ′ larger than the predetermined radius r. FIG. 35 (f) shows a least square approximation circle 3512 obtained from the edge 3511 of the contact portion 261. The radius r ″ of the least square approximate circle 3512 is affected by the dust 3500 and becomes larger than the predetermined radius r. The distance r ′ from the center of the outer peripheral portion to which the dust 3500 is attached is the minimum. Also deviating from the radius r ″ of the square approximation circle 3512. That is, the roundness obtained from the edge 3501 of the contact portion 261 to which no dust is attached substantially satisfies the design value, but the roundness obtained from the edge 3501 of the contact portion 261 to which no dust 3500 is attached is the design value. Does not meet.

  As described above, the measurement control unit 315 may compare the roundness of the extracted edge with a threshold value in order to determine that the cross-sectional shape of the contact unit 261 is not a predetermined shape. In particular, the measurement control unit 315 may obtain a least square approximation circle 3512 from the extracted edge, and may determine that there is dust 3500 to be cleaned at the position of the edge that deviates from the least square approximation circle 3512.

  As an alternative, the measurement control unit 315 stores the image Ic1 of the contact unit 261 generated by the imaging unit 201 when no dust is attached in the storage device 33, and the contact unit 261 generated by the imaging unit 201. It may be determined that the shape of the contact portion 261 is not a predetermined shape by comparing the image Ic2 and the image Ic1. For example, the measurement control unit 315 may generate a difference image between the image Ic1 and the image Ic2, and may determine that the shape of the contact unit 261 is not a predetermined shape when a pixel having a difference larger than a threshold value is found. Further, the measurement control unit 315 may determine that the dust 3500 is attached to a pixel position where the difference is larger than the threshold value.

  As an alternative, the measurement control unit 315 extracts the edge of the contact unit 261 from the image Ic1 of the contact unit 261 generated by the imaging unit 201 when dust is not attached, obtains the diameter, and stores it in the storage device 33. In addition, if the difference between the stored diameter and the diameter obtained in the same manner from the image Ic2 exceeds the threshold value, it may be determined that the shape of the contact portion 261 is not a predetermined shape. This technique can detect even oil that adheres substantially uniformly to the entire contact portion 261. For example, the technique for detecting the deviation between the least square approximation circle and the distance from the center to the edge cannot detect oil adhering to the entire contact portion 261. Therefore, in a measurement environment in which liquid or the like easily adheres to the entire contact portion 261, diameter comparison may be advantageous.

● Function of Measurement Control Unit FIG. 36 shows the function of the measurement control unit 315. The edge extraction unit 3601 extracts the edge of the outer shape (cross-sectional shape) of the contact part 261 from the images Ic1 and Ic2 of the contact part 261. The approximate circle determination unit 3602 calculates a least square approximate circle by applying a least square fitting to the position data (coordinate data) of each edge extracted by the edge extraction unit 3601. For example, the shape determination unit 3603 determines whether the cross-sectional shape of the contact unit 261 is a predetermined shape based on each edge extracted by the edge extraction unit 3601 and the minimum approximate circle. For example, the shape determination unit 3603 obtains the distance between each edge and the minimum approximate circle, and determines whether each distance exceeds a predetermined threshold. The comparison information 3605 includes a threshold value and a reference image for detecting the attached matter. The result output unit 3604 outputs the determination result of the shape determination unit 3603 to the display unit 21 via the display control unit 312. Note that all or part of the functions of the control device 31 may be realized by a processor such as a CPU executing a control program, or may be realized by hardware such as an FPGA or an ASIC. ASIC is an abbreviation for application specific integrated circuit. FPGA is an abbreviation for field programmable gate array. The control program is stored in a computer readable storage medium such as the storage device 33.

Flowchart FIG. 37 is a flowchart showing a probe check process executed by the controller 3. When the start condition for the probe check process is satisfied, the controller 3 starts the probe check process. The start condition is, for example, that the user has instructed execution of the probe check process through the input receiving unit 311. In addition, the start condition may be that the image measurement apparatus 1 is started by being supplied with power from a commercial power source or the like. In addition, the start condition may be that the setting mode of the image measurement device 1 has changed to the measurement mode. The start condition may be immediately before measurement of each measurement element. When a plurality of probe measurement points are set for one measurement element, the start condition may be immediately before measurement of each probe measurement point. As described above, the probe check process may be executed once for one workpiece W, or the probe check process may be executed once for one measurement process using the probe 26. Further, the probe check process may be executed once for one measurement element measured using the probe 26. Further, the probe check process may be executed once for one measurement point.

  In step S <b> 801, the measurement control unit 315 causes the illumination control unit 314 to light the probe light source 263. Note that the measurement control unit 315 may display a message on the display unit 21 indicating that nothing should be placed on the stage. This is because when the workpiece W or the like is placed on the stage 23, the workpiece W is reflected in the image of the contact portion 261, and the edge extraction accuracy of the contact portion 261 is lowered.

  In step S <b> 802, the measurement control unit 315 controls the camera 200 through the imaging control unit 313, causes the imaging unit 201 of the camera 200 to photograph the lighting contact unit 261, and sets the contact unit 261 generated by the camera 200 and the imaging control unit 313. An image Ic2 is acquired. The image Ic2 may be held in the storage device 33.

  In step S <b> 803, the measurement control unit 315 (shape determination unit 3603) detects attached matter attached to the contact unit 261 based on the image Ic <b> 2 of the contact unit 261. For example, the shape determination unit 3603 sets a flag when detecting an attached substance, and resets the flag when no attached object is detected. The flag is held in the storage device 33.

  In S804, the measurement control unit 315 (shape determination unit 3603) determines whether or not the contact part 261 has a predetermined shape based on the detection result (flag) of the adhering substance, that is, whether or not the adhering substance is attached to the contact part 261. To do. If it is determined that there is no deposit on the contact part 261, the measurement control part 315 proceeds to S805. In S805, the measurement control unit 315 (result output unit 3604) outputs, as a determination result, a message indicating that the contact unit 261 does not need to be cleaned or that the contact unit 261 is in a good state to the display unit 21. . If the attachment position of the attached matter is specified, the result output unit 3604 may execute a highlighting display for emphasizing the attached position of the attached matter in the image Ic2. For example, the result output unit 3604 may display the image Ic2 on the display unit 21 and display a figure (circle, square, etc.) surrounding the attachment position in an overlapping manner.

  On the other hand, if it is determined in S803 that the deposit is attached to the contact portion 261, the measurement control unit 315 proceeds to S806. In S806, the measurement control unit 315 (result output unit 3604) outputs, as a determination result, a message indicating that the contact unit 261 needs to be cleaned or that the contact unit 261 is not in a good state to the display unit 21. . In this case, the measurement control unit 315 may prohibit the measurement of the workpiece W until the cleaning of the contact unit 261 is completed by the user. In addition, when a key indicating the completion of cleaning is operated through the input receiving unit 311, the measurement control unit 315 may return to S <b> 802 and perform the processing subsequent to S <b> 802 again on the cleaned contact unit 261. Thereby, when the deposit is removed, the measurement control unit 315 may permit the measurement of the workpiece W.

Detection of attached matter based on roundness FIG. 38 is a flowchart showing an example of the attached matter detection process (S803) executed by the controller 3.

  In step S901, the edge extraction unit 3601 extracts the edge of the contact unit 261 in the image Ic2. Thereby, the positions (coordinates) of a plurality of edges are obtained. That is, the edge of the contact portion 261 in the image Ic2 is converted into a set of edge points (edge point group).

  In step S <b> 902, the approximate circle determination unit 3602 applies a least square method (least square fitting) to the positions of the plurality of edge points obtained by the edge extraction unit 3601, and displays a least square approximate circle indicating the cross-sectional shape of the contact unit 261 ( The least square fitting circle).

  In step S <b> 903, the shape determination unit 3603 calculates the distance between each edge point obtained by the edge extraction unit 3601 and the approximate circle. That is, the shape determination unit 3603 includes a distance calculation unit. This distance may be used as a parameter for obtaining a so-called roundness. That is, the distance may be read as roundness.

  In S904, the shape determination unit 3603 compares the distance obtained for each edge point with the threshold value included in the comparison information 3605, and determines whether there is a distance exceeding the threshold value. If there is a distance exceeding the threshold value, there is a high possibility that the deposit is attached to the contact part 261, and the shape determination unit 3603 proceeds to S905. In step S905, the shape determination unit 3603 sets a flag to indicate that an attached object has been detected. On the other hand, if there is no distance exceeding the threshold value, there is a high possibility that the adhering matter has not adhered to the contact part 261, so the shape determining part 3603 proceeds to S906. In S906, the shape determination unit 3603 resets the flag to indicate that no adhered matter has been detected.

Attachment Detection Based on Image Comparison FIG. 39 is a flowchart showing an example of the attachment detection process (S803) executed by the controller 3. In this example, it is assumed that an image Ic1 of the contact portion 261 to which no deposit is attached is stored in the storage device 33 as a reference image. A reference image is included in the comparison information 3605. In the image comparison, the edge extraction unit 3601 and the approximate circle determination unit 3602 are not necessary.

  In step S <b> 1001, the shape determination unit 3603 reads the reference image from the storage device 33. In step S <b> 1002, the shape determination unit 3603 calculates a difference for each pixel with respect to the reference image of the image Ic <b> 2 of the contact unit 261. That is, the shape determination unit 3603 has a difference calculation unit. In S1003, the shape determination unit 3603 determines whether there is a pixel whose difference exceeds the threshold. It is assumed that the threshold value is also included in the comparison information 3605. If there is a pixel whose difference exceeds the threshold, there is a high possibility that the deposit is attached to the contact part 261, and the shape determination unit 3603 proceeds to S905. On the other hand, if there is no pixel whose difference exceeds the threshold value, there is a high possibility that the adhering matter has not adhered to the contact portion 261, and the shape determining unit 3603 proceeds to S906. Thus, the deposit may be detected by comparing the image Ic1 and the image Ic2 of the contact portion 261 to which the deposit is not adhered.

Detection of attached matter based on diameter (sphere diameter) FIG. 40 is a flowchart showing an example of the attached matter detection process (S803) executed by the controller 3. As described above, a liquid such as oil may uniformly adhere to the outer periphery of the contact portion 261. For detection of such an adhering matter, an adhering matter detection process based on the diameter (spherical diameter) is suitable. In this example, it is assumed that the reference diameter obtained from the image Ic1 of the contact portion 261 to which no deposit is attached is stored in the storage device 33 in advance. The reference diameter may be input by the user through the input receiving unit as a threshold value. The reference diameter is included in the comparison information 3605.

  In S1101, the shape determination unit 3603 calculates the diameter of the contact unit 261 in the image Ic2. The diameter may be calculated from the edge of the contact part 261 obtained from the image Ic2. In this case, a diameter calculating unit may be provided instead of the approximate circle determining unit 3602.

  In S1102, the shape determining unit 3603 determines whether the diameter of the contact unit 261 in the image Ic2 exceeds a threshold value (reference diameter). If the diameter of the contact part 261 exceeds the threshold value, there is a high possibility that an adhering substance such as a liquid is attached to the contact part 261, and the shape determination part 3603 advances to S905. On the other hand, if the diameter of the contact part 261 does not exceed the threshold value, there is a high possibility that an adhering substance such as a liquid has not adhered to the contact part 261, and the shape determination part 3603 advances to S906.

In the embodiment described above, the images Ic1 and Ic2 of the contact portion 261 both turn on the reflection illumination unit 28, turn off the transmission illumination unit 25, and turn on the probe light source 263. It was a reflection image obtained by photographing. However, as shown in FIG. 41A, even if the deposit is attached to the contact portion 261, the deposit may not appear in the image Ic2. When the adhering matter is an object formed of a material that hardly reflects the light from the contact portion 261, the adhering matter is difficult to appear in the image Ic2. On the other hand, as shown in FIG. 41B, if the probe light source 263 is turned off, the transmission illumination unit 25 is turned on and the contact portion 261 is photographed, and the transmission image Ic2 ′ is generated, the edge of the dust 3500 is present. May be clear. Therefore, the transmission image Ic2 ′ may be used instead of the image Ic2 described above. Alternatively, both the detection process using the image Ic2 and the detection process using the transmission image Ic2 ′ may be executed. Thereby, it will be possible to detect the deposit with high accuracy.

  Moreover, both the detection process by the method based on the roundness and the detection process based on the image comparison or the diameter may be executed. As a result, the adhering matter is detected by taking advantage of each detection process, so that the adhering matter detection accuracy will be improved.

● User interface (UI)
FIG. 42 shows an example of a UI indicating the determination result. The UI 4200 generated by the result output unit 3604 includes a guidance message 4201 regarding the probe detection process and a button 4202 for the user to instruct execution of the probe detection process. On the image display unit 4203, an image Ic2 generated by photographing the contact unit 261 is rendered. A dialog box 4204 is a UI for indicating a determination result, and may include a message for prompting the user to perform cleaning. Further, the cooperative display 4205 may be displayed over the image Ic2 in order to emphasize the position of the deposit.

<Summary>
As illustrated in FIG. 1, the image measurement apparatus 1 includes a stage 23 on which a workpiece W is placed, an imaging unit 201 that captures an image of the workpiece W placed on the stage 23 and generates an image, and an imaging unit 201. The probe 26 having the contact portion 261 that can come into contact with the side surface of the workpiece W placed on the stage 23 is provided. Furthermore, when the image measuring apparatus 1 is in contact with the horizontal drive unit 24 that moves at least one of the stage 23 and the probe 26 substantially parallel to the mounting surface of the stage 23, and the contact unit 261 and the side surface of the workpiece W. And a measuring unit (contact position specifying unit 357) that measures the position of the side surface of the workpiece W using the images Ic1 and Ic2 generated by the imaging unit 201. In particular, the image measurement apparatus 1 uses the shape determination unit 3603 for determining whether the shape of the contact unit 261 in the image of the contact unit 261 generated by the imaging unit 201 is a predetermined shape, and the determination result of the shape determination unit 3603. It has an output part (result output part 3604 and display part 21) to output. When dust 3500 or liquid adheres to the contact portion 261, the measurement accuracy is lowered. Further, when dust 3500 or liquid adheres to the contact portion 261, the shape of the contact portion 261 in the image Ic2 deviates from a predetermined shape. Therefore, by notifying the user of the determination result as to whether or not the shape of the contact part 261 is a predetermined shape, the user can easily know the cleaning timing of the contact part 261, and usability is improved. In addition, since the user can perform cleaning of the contact portion 261 based on the determination result, a decrease in measurement accuracy is also suppressed.

  The shape of the contact portion 261 may be a three-dimensional object having a certain shape such as a sphere, a cylinder, or a polygonal column. For example, the contact part 261 is a substantially spherical body. The shape determination unit 3603 extracts the horizontal cross-sectional shape of the contact part 261 from the image Ic2 of the contact part 261, and determines whether the extracted horizontal cross-sectional shape is a predetermined shape. As shown in FIG. 1, since the contact part 261 is disposed on the optical axis of the imaging part 201, the edge of the contact part 261 in the image Ic2 is substantially equal to the edge of the horizontal sectional shape. In addition, since the contact portion 261 moves horizontally relative to the workpiece W and contacts the side surface of the workpiece W, the horizontal cross-sectional edge (outer periphery or outer edge) of the contact portion 261 contacts the side surface of the workpiece W. Therefore, if dust 3500 or the like adheres to this edge, a measurement error may occur. Focusing on the edge of the horizontal cross-sectional shape of the contact portion 261, the adhesion of a foreign object is detected.

  The shape determination unit 3603 may determine whether the horizontal cross-sectional shape is a predetermined shape based on the roundness of the horizontal cross-sectional shape. If the contact part 261 is a substantially spherical body, the edge of the horizontal cross-sectional shape is a circle. Therefore, by attaching attention to the roundness of the horizontal cross-sectional shape, the adhesion of foreign matter such as dust 3500 can be accurately detected. The image measurement apparatus 1 may include a reception unit (input reception unit 311) that receives an input of a roundness threshold value. The shape determination unit 3603 may determine whether the horizontal cross-sectional shape is a predetermined shape by comparing the roundness of the horizontal cross-sectional shape calculated from the image Ic2 with a threshold value. This threshold may be a tolerance, for example.

  The shape determination unit 3603 may determine whether the horizontal cross-sectional shape is a predetermined shape by comparing the diameter of the horizontal cross-sectional shape with the diameter of the predetermined shape. When a liquid such as oil adheres to the contact portion 261, the diameter of the contact portion 261 increases substantially uniformly. Utilizing this characteristic, even a liquid foreign substance can be detected with high accuracy. The image measurement apparatus 1 may further include a reception unit (input reception unit 311) that receives an input of a diameter threshold value. The shape determination unit 3603 may determine whether the horizontal cross-sectional shape is a predetermined shape by comparing the diameter of the horizontal cross-sectional shape with a threshold value. The threshold for the diameter may be a tolerance.

  As described with reference to FIG. 38 and the like, the shape determination unit 3603 extracts the edge of the contact portion 261 in the image of the contact portion 261 as a horizontal cross-sectional shape, and obtains an approximate circle from the extracted edge by the least square method. By comparing the approximate circle and the position of each edge of the contact portion 261, it may be determined whether the horizontal cross-sectional shape is a predetermined shape. When the dust 3500 adheres to the side surface of the contact portion 261, a part of the edge extracted from the image Ic2 deviates from the approximate circle. Using this characteristic, the dust 3500 is detected with high accuracy.

  The image measurement device 1 may further include a storage unit (storage device 33) that stores a reference image that is an image of the contact unit 261 having a predetermined shape. As described with reference to FIG. 39, the shape determining unit 3603 determines whether the shape of the contact unit 261 is a predetermined shape by comparing the image of the contact unit 261 generated by the imaging unit 201 with the reference image. May be. As described above, it is possible to detect the foreign matter by using the image of the contact portion 261 to which no foreign matter is attached as the reference image. For example, the shape determination unit 3603 extracts a predetermined shape from the reference image, and compares the extracted predetermined shape with the horizontal cross-sectional shape of the contact unit 261 extracted from the image of the contact unit 261 generated by the imaging unit 201. May be.

  The image measuring apparatus 1 includes a light source (probe light source 263) that emits light from the contact unit 261 and a control unit (control device 31 including an illumination control unit 314 and a measurement control unit 315) that controls turning on and off of the light source. Have. When acquiring the image of the contact part 261, the control device 31 turns on the light source to cause the contact part 261 to emit light. Thereby, it becomes easy to detect a foreign substance that easily reflects the light of the contact portion 261. Note that the control device 31 may turn off the light source when acquiring the image of the contact portion 261. Thereby, it becomes easy to detect the foreign matter which is hard to reflect the light of the contact part 261. FIG.

  The shape determination unit 3603 may extract the image of the contact unit 261 from the image generated by the imaging unit 201 when the workpiece W is not placed on the stage 23. Thereby, since it is not influenced by the workpiece | work W, it becomes possible to detect a foreign material accurately.

  The shape determination unit 3603 may extract the image of the contact unit 261 from the image generated by the imaging unit 201 when the contact unit 261 contacts the side surface of the workpiece W. Thus, by incorporating the processing for detecting foreign matter in the measurement sequence for measuring the workpiece W, it is possible to reduce the work time dedicated to detection and efficiently detect foreign matter.

  The imaging unit 201 generates an image of the contact unit 261 when the contact unit 261 is located in the focusing range of the imaging unit 201. As a result, the sharpness of the edge of the contact portion 261 increases, so that the edge of the foreign matter adhering to the vicinity of the edge is also sharpened, and the foreign matter detection accuracy is improved.

  The output unit formed by the display unit 21 or the like may output a message prompting cleaning of the contact unit 261 when the shape of the contact unit 261 is not a predetermined shape. This can directly appeal to the user that cleaning is necessary. Note that the image measurement device 1 may include a sound source that outputs sound and warning sound and a speaker, which may prompt cleaning.

  As illustrated in FIG. 42, the output unit may output an image of the contact unit 261 and emphasize the position of the deposit in the image. As a result, it becomes possible to inform the user of the position of the foreign matter, and the work efficiency of the cleaning will be improved.

DESCRIPTION OF SYMBOLS 1 Image measuring apparatus, 201,206 Imaging part, 21 Display part, 23 Stage, 24 Horizontal drive part, 26 Probe, 261 Contact part, 263 Probe light source, 31 Control apparatus, 311 Input reception part, 315 Measurement control part, 33 Storage device, 3601 edge extraction unit, 3602 approximate circle determination unit, 3602 shape determination unit, 3604 result output unit

Claims (16)

A stage on which the workpiece is placed;
An imaging unit that images the workpiece placed on the stage and generates an image;
In the field of view of the imaging unit, a probe having a contact part that can come into contact with the side surface of the workpiece placed on the stage;
A drive unit that moves at least one of the stage and the probe substantially parallel to the mounting surface of the stage;
An image measuring apparatus comprising: a measuring unit that measures a position of the side surface of the workpiece using an image generated by the imaging unit when the contact unit and the side surface of the workpiece are in contact with each other;
A shape determination unit that determines whether the shape of the contact part in the image of the contact part generated by the imaging unit is a predetermined shape;
An image measurement apparatus further comprising: an output unit that outputs a determination result of the shape determination unit. The contact portion is substantially spherical;
2. The shape determination unit according to claim 1, wherein the shape determination unit extracts a horizontal cross-sectional shape of the contact part from an image of the contact part, and determines whether the extracted horizontal cross-sectional shape is the predetermined shape. Image measuring device.   The image measurement apparatus according to claim 2, wherein the shape determination unit determines whether the horizontal cross-sectional shape is the predetermined shape based on a roundness of the horizontal cross-sectional shape. A reception unit that receives an input of the threshold value of the roundness;
The image according to claim 3, wherein the shape determination unit determines whether the horizontal cross-sectional shape is the predetermined shape by comparing the roundness of the horizontal cross-sectional shape with the threshold value. measuring device.   The image according to claim 2, wherein the shape determination unit determines whether the horizontal cross-sectional shape is the predetermined shape by comparing the diameter of the horizontal cross-sectional shape with the diameter of the predetermined shape. measuring device. A reception unit that receives an input of a threshold value of the diameter;
The image measuring device according to claim 5, wherein the shape determination unit determines whether the horizontal cross-sectional shape is the predetermined shape by comparing the diameter of the horizontal cross-sectional shape with the threshold value. .   The shape determination unit extracts an edge of the contact part in the image of the contact part as the horizontal cross-sectional shape, obtains an approximate circle from the extracted edge by a least square method, and each of the approximate circle and the contact part The image measurement apparatus according to claim 2, wherein it is determined whether the horizontal cross-sectional shape is the predetermined shape by comparing edge positions. A storage unit that stores a reference image that is an image of the contact unit having the predetermined shape;
The shape determination unit determines whether the shape of the contact part is a predetermined shape by comparing an image of the contact part generated by the imaging unit and the reference image. The image measuring device described in 1.   The shape determination unit extracts the predetermined shape from the reference image, and compares the extracted predetermined shape with a horizontal cross-sectional shape of the contact portion extracted from the image of the contact portion generated by the imaging unit. The image measuring apparatus according to claim 8, wherein A light source that emits light from the contact portion;
A control unit that controls turning on and off of the light source;
The image measuring apparatus according to claim 1, wherein the control unit turns on the light source to emit light when the image of the contact unit is acquired. A light source that emits light from the contact portion;
A control unit that controls turning on and off of the light source;
The image measurement apparatus according to claim 1, wherein the control unit turns off the light source when acquiring an image of the contact unit.   The shape determination unit extracts an image of the contact unit from an image generated by the imaging unit when a work is not placed on the stage. The image measuring device described in 1.   The said shape determination part extracts the image of the said contact part from the image produced | generated by the said imaging part, when the said contact part and the side surface of the said workpiece | work contact. The image measuring device according to claim 1.   The image measurement according to any one of claims 1 to 13, wherein the imaging unit generates an image of the contact unit when the contact unit is located in a focusing range of the imaging unit. apparatus.   The image measuring apparatus according to claim 1, wherein the output unit outputs a message that prompts cleaning of the contact part when the shape of the contact part is not the predetermined shape.   The image measurement apparatus according to claim 1, wherein the output unit outputs an image of the contact unit and emphasizes the position of the deposit in the image.