JP6797639B2 - Image measuring device - Google Patents

Description

The present invention relates to an image measuring device, and more particularly, to an improvement of an image measuring device in which a probe is brought into contact with a work on a stage, the position of the probe is detected by an image, and the dimensions of the work are obtained.

The image measuring device is a dimensional measuring device that photographs a work placed on a stage, acquires a work image, extracts edges from the work image, and obtains the dimensions of the work. The work image has an extremely accurate similarity to the work regardless of the position in the height direction of the camera, and the actual dimensions and angles on the work are detected by determining the distance and angle on the work image. can do. Edge extraction is performed by analyzing the change in brightness of the work image to detect edge points, and fitting geometric figures such as straight lines, circles, and arcs to the detected multiple edge points. A boundary, a concave or convex contour on the work, or the like is required as an edge. The dimensions of the work are obtained as the distance and angle between the edges obtained in this way. In addition, the quality of the work is judged by comparing the difference (error) between the obtained dimensional value and the design value with the tolerance.

In some image measuring devices as described above, the probe is brought into contact with the side surface of the work placed on the stage to determine the dimensions of the work (Non-Patent Document 1). The probe is arranged in the imaging field of view of the camera, and the contact position with the work is determined by specifying the position of the probe from the captured image of the probe in the state of being in contact with the side surface of the work.

Guijun Ji, Heinrich Schwenke, Eugen Trapet, "Ampto-Mechanical Microprobe System Forming Very Small Parts on CMMs (An Opti-Mechanical MicroMeasure) (USA), International Society of Optical Engineers (SPIE) Vision Geometry VII (Vision Geometry VII), July 20-22, 1998, Vol. 3454, p. 348-353

33 and 34 are views showing an operation example of the image measuring device. The work W to be measured is shown in FIG. 33A, and the work image Iw is shown in FIG. 33B. The work W includes a base member w ₁ and two projecting portions w ₂ formed on the base member w ₁ . When measuring the distance A between the inner side surfaces Sa of the _two protrusions w ₂ , the distance B between the outer side surfaces Sb, and the distance C between the side surfaces Sc of the base member w ₁ , the inside of the protrusion w ₂ Since is a curved surface shape, it is difficult to accurately identify the edge of the side surface Sa from the work image Iw as compared with the edge of the side surface 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 captured workpiece image Iw in the state 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 because 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 in the imaging field of view. Therefore, if this type of image measuring device is used, the dimensions can be accurately obtained even at the measurement location where the edge cannot be accurately specified from the work image Iw.

By the way, when the probe Pr collides with the side surface of the work W, a large force acts on the probe Pr and the work W. If the shaft that supports the probe Pr is made of metal, the work W is pushed by the probe Pr and moves when the probe Pr collides with the work W, and the measurement accuracy of the position of the side surface is lowered. When the probe Pr is supported by a very soft and thin member (filament-like member such as an optical fiber), the work W does not move even if the probe Pr collides with the work W, so that the measurement accuracy of the side position is improved. However, the measurement accuracy is lowered due to the vibration of the probe Pr. Waiting until the vibration of the probe Pr is sufficiently attenuated makes it difficult to measure a large number of workpieces W in a short time. Therefore, a support mechanism for the probe Pr that is not easily affected by vibration and that does not easily move the work W is required. Therefore, an object of the present invention is to provide a probe support mechanism capable of suppressing a decrease in measurement accuracy.

The image measuring device according to the first aspect of the present invention is
The stage on which the work is placed and
An imaging unit that images the work placed on the stage and generates an image,
Within the field of view of the imaging unit, a contact portion mounted on the stage and at least partially extending in the vertical direction and capable of contacting the side surface of the work, and an inflexible shaft having the contact portion fixed to one end. With a probe that has
A drive unit that moves at least one of the stage and the probe substantially parallel to the mounting surface of the stage.
A support mechanism that supports the probe and
An image measuring device including a measuring unit that measures the position of a side surface of the work using an image generated by the imaging unit when the contact unit and the side surface of the work come into contact with each other.
The support mechanism
A movable part that holds the shaft and moves together with the shaft,
A fixed portion provided facing the movable portion and a fixed portion
An urging mechanism that urges the movable portion so that the movable portion and the fixed portion come into contact with each other at at least three points. When the contact portion is pressed against the side surface of the work, the movable portion is combined with the shaft. Has an urging mechanism that urges the movable portion to be restored to the initial position when it moves from the initial position.
The positions of the three points are characterized by being on the same spherical surface.

According to the present invention, a probe support mechanism capable of suppressing a decrease in measurement accuracy is provided.

It is a system diagram which showed one configuration example of the image measuring apparatus 1 by embodiment of this invention. It is explanatory drawing which shows typically an example of the operation of the image measuring apparatus 1 of FIG. It is explanatory drawing which shows typically an example of the operation when the probe 26 is brought into contact with a work W on a stage 23. It is a figure which showed an example of the operation of the image measuring apparatus 1 of FIG. 1, and shows the case where the position of the contour line 14 is specified and the distance D between the side surfaces of a work W is calculated. It is a block diagram which showed one configuration example of the controller 3 of FIG. It is a block diagram which showed one configuration example of the input reception part 311 of FIG. It is a figure which showed an example of the operation at the time of designating a contact position in the input reception part 311 of FIG. It is a figure which showed an example of the operation at the time of the pattern image registration in the input reception part 311 of FIG. It is a figure which showed an example of the operation at the time of designating a contact position in the input reception part 311 of FIG. 5, and shows the table which corresponded the shape type and the number of scan paths. It is a figure which showed an example of the operation at the time of designating a scan position in the input management unit 311 of FIG. 5, and shows the case where the number of scan paths differs depending on the length of the contour line L. It is a block diagram which showed one configuration example of the measurement control unit 315 of FIG. It is a flowchart which showed an example of the operation at the time of measurement setting in the controller 3 of FIG. It is a figure which showed an example of the operation at the time of measurement setting in the image measuring apparatus 1 of FIG. 1, and shows the work W to be registered, and the pattern image Ip. It is a figure which showed an example of the operation at the time of measurement setting in the image measuring apparatus 1 of FIG. 1, and shows the setting screen 100 displayed on the display unit 21. It is a figure which showed the tolerance setting screen 101 at the time of designating a design value and a tolerance. It is a figure which showed the feature amount setting screen 102 at the time of designating a feature amount information. It is a flowchart which showed an example of the detailed operation about step S103 (setting of an image measurement element) of FIG. It is a figure which showed an example of the operation at the time of setting of the image measurement element in the image measurement apparatus 1 of FIG. It is a flowchart which showed an example of the detailed operation about step S104 (setting of a probe measurement element) of FIG. It is a figure which showed an example of the operation at the time of setting of the probe measuring element in the image measuring apparatus 1 of FIG. It is a figure which showed the operation example at the time of adjusting the contact target position on a model image Im. It is a figure which showed the operation example when the start position of a scan operation interferes with other parts. It is a figure which showed the operation example at the time of adjusting the height position of a scanning operation on a model image Im. It is a figure which showed the operation example at the time of designating the moving method when the probe 26 moves between contact target positions. It is a flowchart which showed an example of the detailed operation about step S107 (registration of feature amount information) of FIG. It is a flowchart which showed an example of the detailed operation of the step S201 of FIG. 17, the step S301 of FIG. 19, and the step S401 (designation of shooting conditions) of FIG. It is a flowchart which showed an example of the operation at the time of continuous measurement in the controller 3 of FIG. It is a flowchart which showed an example of the operation at the time of continuous measurement in the controller 3 of FIG. It is a figure which showed an example of the operation at the time of continuous measurement in the image measuring apparatus 1 of FIG. It is a figure which showed an example of the operation at the time of continuous measurement in the image measuring apparatus 1 of FIG. It is a figure which showed an example of the operation at the time of continuous measurement in the image measuring apparatus 1 of FIG. It is a flowchart which showed an example of the detailed operation about step S615 (scan operation) of FIG. 28. It is a figure which showed the operation example of the conventional image measuring apparatus. It is a figure which showed the operation example of the conventional image measuring apparatus. It is a figure which shows the support mechanism of a probe. It is a figure which shows the non-movable member and the movable member. It is a figure explaining the assembling method of a non-movable member and a movable member. It is a figure explaining the assembling method of a non-movable member and a movable member. It is a figure which shows the non-movable member. It is a figure which shows the urging mechanism and the movable mechanism. It is a figure explaining the movement of a contact part and a movable member. It is a figure explaining the movement of a contact part and a movable member. It is a figure explaining the movement of a contact part and a movable member. It is a figure explaining the movement of a metal sphere. It is a figure which shows the urging mechanism and the movable mechanism. It is a figure which shows the other urging mechanism.

<Image measuring device 1>
FIG. 1 is a system diagram showing a configuration example of an image measuring device 1 according to an embodiment of the present invention. The image measuring device 1 extracts an edge from the work image taken by the work W on the stage 23, and contacts the probe 26 with the work W on the stage 23 to specify the contact position. It is a dimension measuring instrument for obtaining the dimensions of the above, and is composed of a main body 2, a controller 3, a keyboard 41 and a mouse 42. The work W is a measurement object whose shape and dimensions are measured.

The main body 2 is composed of a measurement unit 20, a display unit 21, a vertical drive unit 22, a stage 23, a horizontal drive unit 24, and a transmitted illumination unit 25, and irradiates a work W on the stage 23 with detection light consisting of visible light. A work image is generated by receiving the transmitted light or the reflected light. 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 edges from the work image to obtain the dimensions of the work W is called image measurement, and the position of the probe 26 is detected from the work image in which the probe 26 is in contact with the side surface of the work W, and the probe is probed. The process of obtaining the dimensions of the work W by specifying the coordinates of the contact position between the work W and the work W is called probe measurement.

The display unit 21 is a display device that displays a work image and a measurement result. The vertical drive unit 22 moves the measurement unit 20 and the stage 23 relatively 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. The vertical drive unit 22 may have a configuration in which the height of the probe 26 can be adjusted individually with respect to the measurement unit 20.

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

The transmission illumination unit 25 is a light projecting device that irradiates the work W on the stage 23 with the detected light from below, and is composed of a transmission illumination light source 251, a mirror 252, and a condenser lens 253. The transmitted illumination light source 251 is arranged toward the front. The detection light emitted from the transmission illumination light source 251 is reflected upward by the mirror 252 and emitted through the condenser lens 253. This detected light passes through the stage 23, a part of the transmitted light is blocked by the work W, and the other part is incident on the objective lens 205 of the measuring unit 20.

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

The objective lens 205 is a light receiving lens that collects the detection light from the work W, and is arranged so as to face the stage 23. The imaging units 201 and 206 are cameras that photograph the work W on the stage 23 through the common objective lens 205 and generate work images, respectively.

The image pickup unit 201 is an image pickup device having a low imaging magnification, and is composed of an image pickup element 202 and a low magnification side image pickup lens unit 203 composed of an image pickup lens and an aperture plate. The image sensor 202 receives the detection light from the work W via the low magnification side image pickup lens unit 203 and generates a work 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 is composed of an imaging element 207 and a high magnification side imaging lens unit 208 composed of an imaging lens and an aperture plate, and has an imaging field coaxial with the imaging field of the imaging unit 201. Is formed on the stage 23. The image sensor 207 receives the 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 detected light transmitted through the objective lens 205 is reflected rearward by the half mirror 204 and is imaged on the image sensor 207 via the high magnification side imaging lens unit 208.

Image sensors such as CCDs (Charge Coupled Devices) and CMOS (Complementary Metal Oxide Semiconductors) are used as the image sensors 202 and 207. As the objective lens 205, a telecentric lens having a property of not changing the size of the image even if the position of the objective lens 205 in the vertical direction, that is, the position of the objective lens 205 in the optical axis direction is changed is used.

The coaxial epi-illumination light source 209 is a light projection device for irradiating the work W on the stage 23 with the detected light from vertically above, and is arranged toward the front. The 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 work W on the stage 23 with the detected 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 detected light with respect to the stage 23. As the illumination method of the work W, either transmission illumination, ring illumination, or coaxial epi-illumination can be selected.

<Probe 26>
The probe 26 is a contactor for measuring the size of the work W by contacting the side surface of the work W placed on the stage 23. The probe 26 is movably arranged in the imaging field of view of the imaging unit 201 and in the retracted position. Further, the probe 26 is a self-luminous probe, and is composed of a spherical contact portion 261 that contacts the work W and a metal tube 262 that transmits guide light.

An optical fiber for transmitting guide light is contained inside the metal tube 262. The metal pipe 262 is made of a SUS pipe having sufficient strength, and the shape of the metal pipe 262 does not change even if the contact portion 261 comes into contact with the work W.

The contact portion 261 is arranged at the tip of the metal tube 262 extending from the probe light source 263 and diffuses and radiates the guide light. Since the horizontal cross-sectional area of the spherical contact portion 261 is larger than the horizontal cross-sectional area of the metal tube 262, even when the contact portion 261 is imaged from above by the imaging unit 201, the contact portion The contour of 261 can be imaged. The probe light source 263 is a light source device that generates guide light composed of visible light and causes it to enter the metal tube 262.

The switching drive unit 27 is a horizontal drive unit that mutually switches between a state in which the probe 26 is located at a measurement position in the imaging field of view and a state in which the probe 26 is located in a retracted position 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 a 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 view of the imaging unit 201, but may be the peripheral portion of the imaging field of view as long as the probe 26 is not projected as a subject in the work image.

The controller 3 is a control unit that controls shooting and screen display by the main body 2, analyzes a 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 input units 4 for the user to input operations.

2 to 4 are explanatory views schematically showing an example of the operation of the image measuring device 1 of FIG. 1. FIG. 2 shows a state in which the probe 26 extending from the mounting arm 264 is viewed from above vertically. In the figure, (a) 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 mounting arm 264 is a mounting member for mounting the probe 26 to the housing of the measuring unit 20, and has an L-shape. A rotation shaft 265 in the vertical direction is arranged 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 by a floating structure. When the contact portion 261 comes into contact with the side surface of the work 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 region on the stage 23 in which the detected light is emitted from the transmitted illumination unit 25, and is formed in the imaging area 11.

When the probe 26 is in the measurement position, the contact portion 261 is arranged at the center of the imaging area 11 and the translucent area 12. The contact portion 261 is projected as a subject in the work image taken in this state. By controlling the switching drive unit 27 and rotating the mounting arm 264 by about 180 ° from the state where the probe 26 is in the measurement position, the probe 26 moves to the retracted position.

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

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

In the dimensional measurement using the probe 26, a contact target position when the probe 26 is brought into contact with the side surface of the work W and a scan path passing through the contact target position are specified in advance. The reference height is a height at which the probe 26 does not interfere with the work 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 specified so 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 work that the probe 26 should come into contact with, 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 the measured height and a reference height higher than the measured height. If the probe 26 is relatively moved along the scan path from the start position to the end position in the scan direction with respect to the stage 23, the contact portion 261 can be brought into contact with the side surface of the work W. When it is detected that the probe 26 has come into contact with the side surface of the work W, the probe 26 immediately stops with respect to the stage 23.

The start position of the scan path is the operation start position for starting the above-mentioned scan operation, and the end position is the 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 end position of the scan path are set on the scan path that passes through the contact target position and along the normal line of the contour line of the work W.

FIG. 4 shows a case where the position of the contour line 14 is specified and the distance D between the side surfaces of the work W is calculated. In (a) in the figure, the work W to be measured and the probe 26 brought into contact with the right side surface of the work W are shown. This work W has a stepped step, and the distance D between the right side surface and the left side surface of the upper stage is measured.

In (b) in the figure, a work image Iw composed of a transmitted image captured by transmitted illumination is shown. In the transparent image, it is possible to identify the outer edge of the work W by edge extraction, but it is difficult to identify the contour line inside the outer edge by edge extraction.

In (c) in the figure, a work image Iw composed of a reflected image captured by reflected illumination is shown. 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 work W can be specified by edge extraction. However, since the upper part on the right side of the upper part of the work W has a curved surface shape, it is difficult to accurately identify the contour line on the right side surface by edge extraction as compared with the contour line on the left side surface. In such a case, the contour line 14 on the right side surface can be accurately specified by bringing the probe 26 into contact with the probe 26.

In the work image Iw shown in (c) in the figure, the contour line 14 of the right side surface identified by contacting the probe 26 and the contour line 14 of the left side surface identified by extracting the edge from the edge extraction region 15 are included. It is displayed.

The contact of the probe 26 with the side surface of the work W can be detected by whether or not the position of the contact portion 261 moving along the scan path on the work image Iw has changed by a predetermined threshold value or more within a predetermined time. .. The position of the contact portion 261 is specified, for example, by finding the center of the circle from the edge of the contact portion 261. Further, on the work image Iw when the probe 26 comes into contact with the side surface of the work W, the normal direction and the contact position 13 of the side surface of the work W 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 side surface of the work is detected depending on whether or not the contact portion 261 moving along the scan path has stopped on the work 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 by using a known search technique. Therefore, even if the edge is rounded and the edge cannot be detected accurately on the two-dimensional work image Iw as in the work W of FIG. 4, the probe 26 and the work W can be detected from the position of the contact portion 261. By specifying the coordinates of the contact position 13, it is possible to obtain the dimensions of the edges, which are difficult to detect on the image, 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 geometric figure designated in advance to a plurality of contact positions 13. On the other hand, the position of the contour line 14 on the left side surface is obtained by detecting an edge point from the edge extraction area 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 is composed of 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 is composed of an input receiving unit 311, a display control unit 312, an imaging control unit 313, a lighting 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 drive unit 22, a stage 23 including a horizontal drive unit 24, a probe unit 260 including a switching drive unit 27, a display unit 21, a transmission illumination unit 25, and the like. It is composed of a reflective lighting unit 28. The reflection illumination unit 28 is composed of 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 in which the master piece is captured, or a CAD image composed of CAD data created by CAD (Computer Aided Design).

When the display control unit 312 displays the model image generated from the design data on the display unit 21, the display control unit 312 designs by assuming the image data obtained by imaging the work W placed on the stage 23 from above. Display the model image generated from the data. By doing so, even if the model image is generated from the design data, it is displayed at the same angle as the work image captured by the imaging unit 201 or 206, so that it is easy to specify 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 the user operation received by the input unit 4, and registers various measurement setting information for performing dimensional measurement 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, switches the imaging magnification, and adjusts the imaging timing and the exposure time. The illumination control unit 314 controls the lighting of the transmission illumination unit 25, the coaxial epi-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 the image measurement is switched to the probe measurement, the illumination control unit 314 turns on the probe light source 263, while turning off the transmission illumination unit 25, the coaxial epi-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 image pickup unit 201 or 206. And measure the dimensions.

<Input reception section 311>
FIG. 6 is a block diagram showing a configuration example of the input receiving unit 311 of FIG. The input receiving unit 311 is composed of an imaging and lighting condition designation unit 341, an edge extraction area designation unit 342, a contact position designation unit 343, a measurement setting unit 344, a design value and tolerance designation unit 345, and a feature amount information setting unit 346. Tolerant.

The imaging and illumination condition designation unit 341 specifies imaging conditions such as shooting magnification, exposure time, and gain, and illumination conditions such as illumination type, brightness, and height of the ring illumination unit, based on the user's instruction. It is registered as measurement setting information in the storage device 33.

The edge extraction area designation unit 342 designates the edge extraction area as feature amount information, for example, a coordinate value relative to the pattern image on the model image based on the user's instruction, and uses the storage device 33 as the edge extraction area information. register.

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 designation unit 343 coordinates the contact target position information that determines the probe operation for bringing the probe 26 into contact with the plurality of contact target positions to be contacted by the probe 26 relative to the feature amount information (pattern image). It is specified 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 the position coordinates relative to the pattern image (search data) registered on the model image and the measurement height indicating the height of the side surface of the work to be contacted by the probe 26. The measurement height is specified in advance by the user, for example.

The measurement setting unit 344 extracts the edge of the work W existing on the model image from the edge extraction area designated by the edge extraction area 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 work W existing on the model image is specified, and based on these edges or contact positions, the contour line to be measured from the model image and the contour line to be measured are used. Identify the reference point. Measurement elements (eg, straight lines, circles, arcs, etc.) are identified based on the identified contours and reference points. When the feature amount information is CAD data, the contour line and the reference point are directly specified without edge extraction.

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

The feature amount information setting unit 346 sets the feature amount information for specifying the position and orientation of the work W from the work image captured by the image pickup unit 201 or 206 at the time of executing the measurement. That is, the feature amount information setting unit 346 sets the feature amount information including the search data for specifying the position and the posture of the work W based on the model image based on the instruction of the user, 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 a normalized correlation search, and is set based on the master piece image in which the master piece is captured. In the storage device 33, the pattern image set by the feature amount information setting unit 346 and the contact target position information designated by the contact position designating unit 343 are stored 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. Further, the feature portion may be extracted from the model image so that the pattern image is automatically registered.

By matching the registered pattern image with the work image obtained by capturing the inspection target work W, the position and posture (coordinates) of the work W in the work image can be specified. For matching, known matching techniques, such as normalized correlation search and geometric search, can be used. 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 by the probe 26 and the edge extraction area are designated as the coordinate values relative to the pattern image (search data) registered on the model image. .. The contact target position information includes the contact target position which is the target position where the probe 26 is brought into contact, the scan operation start position which is the position where the scan operation is started, the scan operation end position which is the position where the scan operation is ended, and the work to be contacted. The measured height, which indicates the height of the side surface, is included.

The user places the work W to be inspected on the stage 23, acquires a work image, and executes a matching process using the pattern image (search data) to obtain the contact target position by the probe 26 and the edge. The extraction area can be specified automatically. The contour line of the work W is specified by sequentially bringing the probe 26 into contact with the side surface of the work according to the specified contact target position. In addition, in order to specify a linear contour line, coordinate information of two or more contact positions is required, and in order to specify a circular or arcuate contour line, the coordinates of three or more contact positions Information is needed. Further, it is not always necessary to have two or more contact positions, and when it is desired to measure a specific point, the coordinate information of the contact position of one point can be used for the measurement.

The input receiving unit 311 receives the designation of the measurement element to be measured by the probe 26 on the model image displayed on the display unit 21. The model image displayed on the display unit 21 is a work image in which the work W for measurement setting is captured. 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 specified by the input receiving unit 311 and the arrangement position of the contact target position of the probe 26. The placement rule is information for appropriately designating the contact target position according to the shape type or size of the measurement element. The placement rule consists of, 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.

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

When the measurement control unit 315 executes the measurement, the contact target of the probe is determined according to the position of the measurement element specified by the input reception unit, the shape type or size of the measurement element, and the arrangement rule stored in the storage unit. 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 the edge extraction area is set on the measurement element, the contact position designation unit 343 extracts an edge from the edge extraction area and obtains a contour line for the model image being displayed, and a plurality of positions on the contour line are obtained. The contact target position is specified, and the start position of the scanning operation for bringing the probe 26 closer is specified as a position separated from the contact target position in the normal direction of the contour line.

A symbol indicating the start position of the scan operation is displayed on the model image on the display unit 21, and the contact position designation unit 343 scans the start position of the scan operation, the number of contact target positions on the contour line, and the probe 26. Accepts user operations to change direction and height information.

FIG. 7 is a diagram showing an example of an operation when the contact position is specified in the input receiving unit 311 of FIG. In (a) in the figure, a work W for registering the pattern image Ip and the contact target position information is shown. The workpiece W is, both outer sides of the protruding portion w ₂ formed on the base member w ₁ is curved, the distance D between the side surfaces of the projecting portion w ₂ is measured using a probe 26.

The model image Im is a reflected image captured by the reflected illumination, and a part of the region including the work 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).

In (b) in the figure, the case where the pattern image Ip and the contact target position are directly related is shown. For example, the contact target position is automatically specified by designating the start position and the end position of the scanning operation for the pattern image Ip. The start position and 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. By designating the contact target position, the start position and the end position of the scanning operation may be automatically determined. By directly associating the pattern image Ip with the contact target position in this way, the contact target position coordinates are stored relative to the pattern image (search data).

In (c) in the figure, a case where an edge is extracted from the edge extraction region R and the contour line L specified is associated with the contact target position is shown. An edge point is extracted from the edge extraction area 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 with each other. The position coordinates of the edge extraction area R on the work image input at the time of inspection are automatically specified by matching the work image with the pattern image (search data). An edge point sequence in the edge extraction region R whose position is specified is extracted, and a contact target position is set at a predetermined position with respect to the contour line L specified from this edge point sequence. For example, when the scanning direction is set to approach the contour line L from a position separated by a predetermined distance in the normal direction, a stable approach can be made along the normal line of the contour line L, so that the measurement is stable. To do.

In (d) in the figure, the case where the edge extraction region R and the contact target position are related is shown. By designating the contact target position with respect to the edge extraction region R designated on the pattern image Ip, the pattern image Ip and the contact target position are indirectly associated with each other. By the matching process described above, the position coordinates of the edge extraction region R are specified, and at the same time, the contact target position coordinates are specified.

FIG. 8 is a diagram showing an example of the operation at the time of pattern image registration in the input receiving unit 311 of FIG. 5, and the model image Im when the work W shown in FIG. 7A is imaged by transmission illumination is shown. It is shown. A part of this model image Im is registered as a pattern image Ip for search. As described above, the transmission image captured by the transmission illumination can be used as the pattern image Ip for the search, while the reflection image captured by the reflection illumination can be used to specify the contact target position.

In general, a transmitted image captured by transmitted illumination has a clear edge, and the change in the image due to a change in the surrounding environment is small. Therefore, while registering a pattern image based on the transmitted image captured by the transmitted illumination, the image is captured by the reflected illumination in order to measure the dimension of the inner contour existing in the non-penetrating work shape which cannot be acquired by the transmitted illumination. The contact target position can be specified by the probe 26 based on the reflected image. In this way, the lighting conditions when registering the pattern image can be made different from the lighting conditions when registering the contact target position and the edge extraction area. Further, in order to make the lighting condition at the time of continuous measurement the same as the lighting condition at the time of setting, the lighting condition at the time of setting is registered as the measurement setting information.

As described above, the contact target position is directly or indirectly specified 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. To. 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 when the contact position is specified in the input receiving unit 311 of FIG. 5, and shows a table in which the shape type and the number of scan paths are associated with each other. In (a) in the figure, a table is shown when the number of divisions is fixed. This table is an arrangement standard 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 specified for the three shape types (straight line, circle, and arc).

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

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

Specifically, when the shape type is a straight line, if 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. To. 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 so as to divide the straight line into four equal parts. Further, when the shape type is a circle, if the length of the contour line L is less than the threshold value TH, the number of divisions = 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 value TH, the number of divisions = 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 showing an example of an operation when the contact position is specified in the input receiving unit 311 of FIG. 5, and shows a case where the number of scan paths differs depending on 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 designated as the measurement target region on the model image Im by the user, the contact target position is designated with respect to the contour line L specified by extracting the edge from the edge extraction region R. For example, the contact target position is specified 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 differs depending on the length of the contour line L. The contour line L may be one that is directly specified by a mouse operation or the like.

Further, as in the illustrated scan path, by designating the number of divisions n of 3 or more, n or (n-1) scan paths for equally dividing the contour line L may be specified. .. 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 is set. Two scan paths are specified that divide the On the other hand, when the length of the contour line L is equal to or longer than a certain value, the number of divisions is set to 4, and three scan paths for equally dividing the contour line L are specified.

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 specified. Radius. On the other hand, when the radius is equal to or more than a certain value, the number of divisions is set to 4, and four scan paths for equally dividing the contour line L are specified.

The start position of the scan path is designated as a position 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 opposite to the start position across the contour line L. Further, the scanning direction when the probe 26 is brought close to the side surface of the work W is determined based on the brightness difference on both sides of the edge extracted from the model image Im. The method of determining the start position and end position of the scan path is not limited to the above method. The start position and end position of the scan path may be set relative to the contact target position.

<Measurement control unit 315>
FIG. 11 is a block diagram showing a configuration example of the measurement control unit 315 of FIG. The measurement control unit 315 includes a search processing unit 351, an edge extraction area identification unit 352, an edge extraction processing unit 353, a scan operation determination unit 354, a scan operation control unit 355, a probe detection unit 356, a contact position identification unit 357, and an outline. It is composed of a calculation unit 358 and a dimension calculation unit 359.

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

The edge extraction area specifying unit 352 specifies the edge extraction area on the work image based on the position and orientation of the work W specified by the search processing unit 351 and the edge extraction area information. The edge extraction processing unit 353 extracts edge points from the edge extraction region specified by the edge extraction region identification unit 352.

The scan operation determination unit 354 identifies the position of the contour line by fitting a geometric figure designated in advance as a shape type to a plurality of edge points extracted by the edge extraction processing unit 353, and uses the contact target position information as the contact target position information. Based on this, the scanning operation is determined by specifying the starting position and the scanning 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 causes the horizontal drive unit 24 to sequentially move the probe 26 to a plurality of contact target positions. Control.

The probe detection unit 356 detects that the probe 26 has come into contact with the side surface of the work W. For example, if a work image is repeatedly acquired from the imaging unit 201 or 206 and the position of the probe 26 moving along the scan path on the work image changes by a certain threshold value or more within a certain time, the probe 26 moves to the side surface of the work W. It is judged that they have come into contact. The probe 26 may be provided with a sensor that detects physical contact.

When the contact position specifying unit 357 detects that the probe 26 has come into contact with the side surface of the work W, the contact position specifying unit 357 acquires a work image in which the probe 26 in contact with the side surface of the work W has been taken, and on the work image. The contact position is specified from the position of the probe 26. A plurality of contact positions where the probe 26 comes into contact with the work W are specified based on the position of the probe 26 on the work image and the relative position of the imaging field of view with respect to the stage 23.

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 in 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 work W are brought into contact with each other. Therefore, when the probe 26 is not in contact with the work W, the probe 26 is always located at the center in the imaging field of view. Not limited to this embodiment, the camera side may be configured to move together with the probe 26, or the probe 26 may be configured to move in the imaging field of view.

The contour line calculation unit 358 fits a geometric figure to a plurality of edge points extracted by the edge extraction processing unit 353 or a plurality of contact positions specified by the contact position identification unit 357, thereby causing the contour line to be fitted. Identify the position of.

The dimension calculation unit 359 obtains the dimensions of the work 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 work W is determined by 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 contact of the probe 26. Desired.

For example, the dimensions can be obtained by combining the contour line specified by edge extraction and the contour line specified by the 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, for the portion that can be measured with an image, the time required for dimensional measurement can be shortened by measuring with an image.

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

13 and 14 are diagrams showing an example of the operation at the time of measurement setting in the image measuring device 1 of FIG. FIG. 13A shows the work W to be registered, and FIG. 13B shows the edge extraction area R specified on the pattern image Ip and the symbol Sm indicating the start position of the scanning operation. There is. 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 photographed image in which such a work W is captured as a subject. The measurement points are designated as 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 protrusion w ₂ . 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 designated for the contour line of the work W. On the other hand, the distance between the front and rear side surfaces of the base member w ₁ and the inner diameter of the protruding portion w ₂ are measured by bringing the probe 26 into contact.

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

The model image displayed in the display field 110 is a captured image in which the work W shown in FIG. 12 is captured as a subject. By operating the magnification button 131 or 132, either a low magnification for wide-field measurement or a high magnification for high-precision measurement can be specified as the photographing magnification. Further, by operating the stage adjustment button 133, the position of the stage 23 in the X direction and the position in the Y direction can be adjusted. Further, by operating the Z adjustment button 134, the position of the measurement unit 20 in the Z direction can be adjusted. The lighting type can be specified by operating the lighting button 135. Illumination types include transmission illumination, ring illumination, and coaxial epi-illumination.

The dimension type of the menu column 111 includes distance measurement, angle measurement, and the like. 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, and circles. There are distance measurement between a point and a point, diameter measurement of a circle, and radius measurement of an arc.

In the setting of the image measurement element in step S103, the measurement setting information is specified for the measurement element for performing the 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 specified for the measurement element for contacting the probe 26 to perform the dimension measurement. The processing contents of steps S103 and S104 will be described in detail in FIGS. 17 and 19, respectively. The controller 3 repeats the processing procedure from steps S101 to S104 until the setting is completed for all the measurement elements on the model image (step S105).

Next, the controller 3 specifies the design value and the tolerance (step S106). In this step, the dimensional values calculated from the model image are displayed in association with the contour lines of the measurement elements, and if the dimensional values on the model image are selected by the user, new design values and tolerances are specified, or , Can be changed.

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

In the input field 112, the design value and the upper limit value and the lower limit value of the tolerance are displayed for a plurality of measurement points registered as the measurement setting information, and if the measurement point is selected, the design value, the upper limit value of the tolerance, or the upper limit value of the tolerance is displayed. The lower limit can be newly specified or changed.

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

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

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

Steps S201 to S209 of FIG. 17 are flowcharts showing an example of detailed operation of step S103 (setting of image measurement element) of FIG. 12, and show the operation of the controller 3. First, the controller 3 specifies the shooting conditions described later (step S201), acquires the shot image of the 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 area 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 area (step S205), and fits a geometric figure corresponding to the selected shape type to these edge points to position the contour line. Is determined (step S206).

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

FIG. 18 is a diagram showing an example of an operation at the time of setting the image measurement element in the image measurement device 1 of FIG. In the figure, (a) shows the edge extraction region 116 specified on the model image, and (b) shows the contour line 117 specified by extracting the edge from the edge extraction region 116. There is.

If the positions of the start point and the end point of the measurement element are 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 the end point is automatically designated as the edge extraction area 116. , Is displayed on the model image in association with the measurement element along with the scan direction of the edge point. When the registration of the edge extraction area 116 is completed, the contour line 117 and the dimension value specified by extracting the edge from the edge extraction area 116 are displayed on the model image.

Steps S301 to S315 in FIG. 19 are flowcharts showing an example of detailed operation in step S104 (setting of probe measurement element) in FIG. 12, and show the operation of the controller 3. 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 specifies the contact target position information (step S307). The contact target position information, that is, the contact target position and the scan path, is automatically specified based on the shape type and size of the measurement element. Further, the designated scan path is superimposed and displayed on the model image (step S308).

FIG. 20 is a diagram showing an example of an operation at the time of setting the probe measuring element in the image measuring device 1 of FIG. Since the probe measurement is performed by imaging the probe 26 with the camera 200, where should the probe 26 be brought into contact with the work W, or how should the side surface of the work W be approached? It is difficult for the user to judge for himself. In the image measuring device 1 according to the present embodiment, the contact target position is automatically determined only by designating the edge extraction region as the measurement target region on the model image.

In (a) in the figure, the edge extraction region 118 designated on the model image Im is shown. 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, the annular region including these points is automatically set as the edge extraction region 118. It is specified and displayed on the model image Im.

In (b) in the figure, a contour line 119 identified by extracting an edge from the edge extraction region 118 and a symbol 120 indicating a start position of a scanning operation are shown. 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 designated with respect to the contour line 119, and the 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 evenly spaced along the contour line 119.

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

In (c) in the figure, the contour line 121 specified by contacting the probe 26 and the dimensional value displayed in association with the contour line 121 are shown. When the registration of the contact target position is completed, the contour line 121 specified by bringing the probe 26 into contact with the side surface of the work W is displayed on the model image in the setting screen 100, and is obtained from the contour line 121. The dimension value is displayed in association with the contour line 121.

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

21 and 22 are diagrams showing an example of the operation at the time of setting the probe measuring element in the image measuring device 1 of FIG. FIG. 21A shows a case where the contact target position specified with respect to the contour line 119 on the model image Im is adjusted, and FIG. 21B shows a case where the scanning direction is changed. (C) shows a case where the number of scan paths is changed.

The contact target position designated with respect to 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 operating the mouse 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 inward from the contour line 119. Further, by operating the setting screen 100, the scanning direction can be reversed or a scanning path can be added.

The work W to be registered is shown in (a) of FIG. 22, the contact target position specified on the model image Im is shown in (b), and the error-displayed symbol is shown in (c). 120 is shown. Two scan paths are specified for the contour line 119 corresponding to the right side surface of the work W. The contact target position can be changed by moving the symbol 120 indicating the start position of the scanning operation by operating the mouse or the like.

The measurement time can be shortened when the start position of the scanning operation is closer to the contour line 119 of the measurement location. However, if the start position of the scanning operation is too close to the contour line 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 the dimensional variation of the work W. That is, when the contour line 119 on the right side is the measurement target, if the scan start position is too close to the contour line 119 on the right side, the probe 26 interferes with the work W due to the dimensional variation of the work W during continuous measurement.

When the contact target position designated on the model image Im is close to the contour line 119 to be measured in this way, the contact target position can be adjusted so as to be far from the contour line 119. That is, the start position of the scanning operation can be adjusted so as to be away from the contour line 119 on the right side.

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

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

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

Further, when the measurement height is changed, the vertical drive unit 22 can be controlled to move the probe 26 to the changed measurement height, whereby the height relationship between the work W and the contact portion 261 can be actually confirmed. be able to.

Next, the controller 3 starts a scanning operation, acquires a captured image captured by the probe 26 in contact with the side surface of the master piece, and identifies 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 dimensions of the measurement location based on the position of the contour line, and displays the dimensional values of the measurement results on the model image in association with the measurement elements (steps S313 and S314). The controller repeats the processing procedure from steps S303 to S314 for all the measurement elements on the model image until the setting is completed (step S315).

FIG. 24 is a diagram showing an example of an operation at the time of setting the probe measuring element in the image measuring device 1 of FIG. In the figure, (a) shows the case of the first scan mode, and (b) shows the case of the second scan mode. The first scan mode and the second scan mode are movement methods when the probe 26 moves relatively between the contact target positions with respect to the stage 23, and either the first scan mode or the second scan mode is designated. can do.

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

On the other hand, in the second scan mode, the probe 26 moves relatively between the contact target positions with respect 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 relatively moved between the contact target positions with respect to the stage 23 without switching to the reference height. Let me. However, when moving the probe 26 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 relative to the stage 23 at the same height along the contour line.

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

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

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

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

Next, the controller 3 specifies the illumination condition, the imaging condition, and the photographing magnification (steps S505 to S507). The lighting conditions include the lighting type, the lighting state, the brightness, and the position of the ring lighting 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 related to the designation of the shooting conditions are completed (step S508), and when all the settings are completed, the shooting conditions are stored as measurement setting information. To do.

Steps S601 to S617 of FIGS. 27 and 28 are flowcharts showing an example of the operation at the time of continuous measurement in the controller 3 of FIG. First, the controller 3 reads out the measurement setting information (step S601) and specifies the shooting conditions based on the measurement setting information (step S602). Next, the controller 3 photographs the work W placed on the stage 23 under the above-mentioned imaging conditions to acquire a work image (step S603), and performs a pattern search using the feature amount information to determine the position and orientation of the work W. (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 area (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 the measurement setting information (step S609), the controller 3 calculates the dimension of the measurement point based on the position of the specified contour line (step S610), and the measurement element. The dimensional 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 extracts the edge from the edge extraction area, specifies the scan start position based on the position of the specified contour line (step S614), and performs the scan operation (step S615).

Next, the controller 3 acquires a photographed image taken by the probe 26 in contact with the side surface of the work W, determines the position of the contact point based on the photographed image, identifies the position of the contour line, and measures the position. Calculate the dimensions of the location (step S616). Then, the controller 3 displays the dimensional value of the measurement result on the work image in association with the measurement element (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 work W specified by the pattern search. When the contact target position is associated with the edge extraction area, the contact target is specified by specifying the position of the edge extraction area on the work image based on the position and orientation of the work W specified by the pattern search. The position is specified.

29 to 31 are views showing an example of operation during continuous measurement in the image measuring device 1 of FIG. 1. In FIGS. 29 (b) to (d), (a) to (d) in FIG. 30, 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 done. FIG. 29A shows the pattern image Ip registered as the search data, and FIG. 29B shows the work image Iw captured for the pattern search. Both the pattern image Ip and the work image Iw are transmitted images by transmitted illumination. By matching the work image Iw with the pattern image Ip, the position and orientation of the work W are specified.

FIG. 29 (c) shows the work image Iw captured 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 orientation of the work W specified by the pattern search.

FIG. 29 (d) shows a plurality of edge extraction regions R identified on the work image Iw shown in FIG. 29 (c). The position coordinates of the edge extraction area R are specified based on the position and orientation of the work W and the relative position information registered as the edge extraction area information.

In FIG. 30A, a plurality of contour lines L ₁ and L ₂ identified by extracting an edge from the edge extraction region R are shown. The contour line L ₁ is a contour line when the measurement element is registered as an image measurement element. On the other hand, the contour line L ₂ is a temporary contour line used to specify the contact target position when the measurement element is registered as the probe measurement element, and the position 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. 30 (c) shows a plurality of contact positions P identified by contacting the probe 26. The contact position P is specified based on the work image Iw acquired in a state where the probe 26 is in contact with the side surface of the work 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 work image Iw in which the result of the quality determination of the work 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 work W is judged by comparing the obtained dimensional value with the design value and comparing the error with respect to the design value with the tolerance. The result of this 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 the measurement points are judged to be OK, and the work W is judged to be a good 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 determined to be NG, and the work W is determined to be a defective product.

Steps S701 to S712 of FIG. 32 are flowcharts showing an example of detailed operations for step S615 (scan operation) of 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 to a position corresponding to the start position of the scan path at the reference height (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 drive unit 24 to move the probe 26 relative to the stage 23 in the scanning direction (step S703), and if contact is detected, the probe 26 on the work image. The contact position is calculated based on the position of and the position of the stage 23 (steps S704 and S705). The probe 26 is controlled to approach along the normal of the contour line on the work image. The controller 3 repeats the processing procedure from step S701 to step S705 until the measurement is completed for all the contact target positions, and when the measurement is completed for all the contact target positions, the controller 3 moves the probe 26 to the reference height. This process ends (steps S706 and S707).

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

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

According to the present embodiment, since the position and orientation of the work W are specified from the work image based on the pattern image, the dimensional measurement using the probe 26 is performed only by placing the work W on the stage 23. be able to. Further, since the contact target position to be contacted by the probe 26 is specified based on the contact target position information, a plurality of contact target positions with respect to the work W can be specified only by first specifying a position relative to the pattern image. Can be specified and the probe 26 can be moved in sequence.

Further, since the work image for specifying the position and orientation of the work W is generated in the state where the probe 26 is in the retracted position, the probe 26 is imaged overlapping with the work W or is imaged in the vicinity of the work W. It can be prevented from being done.

Further, according to the present embodiment, a plurality of contact target positions on the side surface of the work 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 specifying the measurement element with, it is possible to automatically identify a plurality of contact target positions and determine the scanning operation by the probe 26.

In the present embodiment, an example in which the horizontal drive 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 drive 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 and Y directions. Alternatively, the horizontal drive unit 24 may be configured to move the stage 23 in the X direction and the probe 26 or the measurement unit 20 in the Y direction.

Further, 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, but 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.

Further, in the present embodiment, an example in which the scan direction of the scan path is specified based on the brightness difference on both sides of the edge has been described, but the present invention does not limit the method of specifying the scan direction to this. Absent. For example, the height information in the vicinity of the measurement point may be acquired by using the focus position of the imaging unit 201 or 206, and the scanning direction may be specified based on the height information. Further, the scanning direction may be configured so that a predetermined direction is specified by default.

Further, in the present embodiment, an example in which the measurement height of the contact target position is specified by the user has been described, but the present invention automatically sets the measurement height by using the focus position of the imaging unit 201 or 206. It may be configured to be specified as a target.

Further, in the present embodiment, an example in which the probe 26 is detected to be in contact with the side surface of the work W has been described based on the work image, but the present invention limits the method of contact detection to this. It's not a thing. For example, a sensor that detects pressure or vibration may be used to detect that the probe 26 has come into contact with the side surface of the work W.

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, but in the present invention, the probe 26 is within the measurement region in the imaging field of view of the imaging unit 201 or 206. It can also be applied to objects that can be moved in the horizontal direction.

Further, in the present embodiment, the image measuring device 1 provided with the self-luminous probe 26 in which the guide light is transmitted from the probe light source 263 via the metal tube 262 has been described, but the present invention describes the probe 26. The configuration is not limited to this. For example, the probe may be one that does not emit guide light.

<Probe support mechanism>
In this embodiment, a metal tube 262 is adopted as a shaft (rod) for supporting the contact portion 261 of the probe 26. Therefore, the vibration generated in the contact portion 261 is attenuated in a short time. On the other hand, since the metal tube 262 has high rigidity and low inflexibility, the work W is pushed when the contact portion 261 comes into contact with the work W, and the position of the work W may be displaced. If a flexible shaft (optical fiber or the like) is used instead of the metal tube 262, the work W will not be pushed even if the contact portion 261 comes into contact with the work W. However, with a flexible shaft, vibration is difficult to attenuate, and a large number of workpieces W cannot be measured in a short time. Therefore, in the present embodiment, a support mechanism for the probe 26, which is not easily affected by vibration and is hard to move the work W, is proposed.

FIG. 35 shows a support mechanism 3500 that supports the probe 26. The support mechanism 3500 has a frame 3550 connected to the switching drive unit 27. The frame 3550 extends parallel to the y-axis direction. The probe 26 has a substantially L-shape, and the contact portion 261 is fixed to a metal tube 262 extending parallel to the z-axis. Further, the other end of the metal tube is also calculated in parallel with the y-axis. As shown in FIG. 35, at least a part of the metal tube 262 of the probe 26 extends in the vertical direction.

A light source 3560 is fixed to the rear end of the frame 3550. A non-movable member 3501 is fixed to the front end of the frame 3550 by a fixture 3551a. The frame 3550 is fixed to the switching drive unit 27. The movable member 3502 is supported by the non-movable member 3501 and is movable relative to the non-movable member 3501. The movable member 3502 holds the metal pipe 262, and when the contact portion 261 moves in contact with the work W, it moves following the contact portion 261.

FIG. 36 shows the details of the non-movable member 3501 and the movable member 3502. Holes 3511a and 3511b through which fixing tools such as screws 3551a are inserted or screwed are provided on the left side surface and the right side surface of the non-movable member 3501. A frame 3550 is fixed to the right side surface and the left side surface of the non-movable member 3501, respectively.

The movable member 3502 has a housing 3520 made of aluminum or the like. A circular central hole 3515 is provided in the center of the housing 3520, and a shaft holding member 3524 for holding the metal tube 262 is inserted therethrough. The housing 3520 and the shaft holding member 3524 may be adhered to each other. A contact portion 261 is fixed to one end of the metal tube 262, but the other end of the metal tube 262 extends to the vicinity of the center of the shaft holding member 3524. An optical fiber 3522 is held inside the metal tube 262. The optical fiber 3522 is not covered with the metal tube 262 from the vicinity of the center of the shaft holding member 3524 to the rear end, and is exposed. The optical fiber 3522 functions as an optical waveguide that transmits the light output from the light source 3560 to the contact portion 261. Although the optical fiber 3522 itself has flexibility, since it is covered with a metal tube 262, the rigidity of the covered portion is high. The optical fiber 3522 may be covered with a metal tube 262 except for the incident end and the exit end of the optical fiber 3522. Three holes 3521a, 3521b, and 3521c for holding magnets are provided on the side surface of the housing 3520.

37 and 38 show an assembling method of the non-movable member 3501 and the movable member 3502. Three magnets are fixed to the housing 3520, and a metal tube 262 of the probe 26 is fixed to the shaft holding member 3524. The non-movable member 3501 and the movable member 3502 are assembled by inserting the contact portion 261 and the metal tube 262 into the central hole 3515 of the non-movable member 3501. FIG. 38 shows that the assembly of the non-movable member 3501 and the movable member 3502 is completed.

FIG. 39 shows the rear surface side of the non-movable member 3501. The rear surface of the non-movable member 3501 is a first facing surface facing the movable member 3502. The front surface of the movable member 3502 is a second facing surface facing the non-movable member 3501. In FIG. 39, the fixtures 3551a and 3551b are screwed to the non-movable member 3501, but the left and right frames 3550 are not shown. Actually, the non-movable member 3501 is fixed to the left and right frames 3550 by the fixtures 3551a and 3551b. The housing of the non-movable member 3501 is provided with three holes 3512a, 3512b, and 3512c for holding a magnet. A magnet 3513a is inserted into the hole 3512a and fixed (adhered or the like). A magnet 3513b is inserted into the hole 3512b and fixed. A magnet 3513c (FIG. 43) is inserted and fixed in the hole 3512c. A ferromagnetic metal sphere 3514a such as iron is attracted to the magnet 3513a by magnetic force. Similarly, a ferromagnetic metal sphere 3514b such as iron is attracted to the magnet 3513b by magnetic force. A ferromagnetic metal sphere 3514c such as iron is attracted to the magnet 3513c by magnetic force. The radius of the metal balls 3514a, 3514b, 3514c is such that a part of the metal balls 3514a, 3514b, 3514c protrudes from the outer surface 3517 of the non-movable member 3501. Here, the ferromagnetic metal spheres 3514a, 3514b, and 3514c are shown as examples of spheres, but spheres such as resin may be adopted. In this case, a mechanism other than a magnet will be required as a mechanism for holding the sphere.

FIG. 40 is a schematic cross-sectional view showing a non-movable member 3501 and a housing of the movable member 3502. In particular, in the present embodiment, the method of supporting the movable member 3502 (the method of urging) has one feature. As described above, the non-movable member 3501 has three magnets 3513a, 3513b, and 3513c, but the movable member 3502 also has three magnets at positions facing these magnets. In FIG. 40, the magnet 3523b is shown among the three magnets included in the movable member 3502. The magnet 3523b is inserted and fixed (adhered, etc.) through the hole 3521b provided in the housing 3520. Here, the magnet 3513b of the non-movable member 3501 is arranged to face the magnet 3523b of the movable member 3502, forming a magnet pair. The metal ball 3514b is in contact with the magnet 3513b of the non-movable member 3501 and the magnet 3523b of the movable member 3502. When the north pole of the magnet 3513b of the non-movable member 3501 is in contact with the metal sphere 3514b, the south pole of the magnet 3523b of the movable member 3502 is in contact with the metal sphere 3514. When the magnet 3513b of the non-movable member 3501 and the magnet 3523b of the movable member 3502 are pulled together via the metal ball 3514b, the movable member 3502 is pressed against the non-movable member 3501 and supported by the non-movable member 3501. .. In order to suppress the metal ball 3514b from falling off, the magnetic force of the magnet 3513b of the non-movable member 3501 is stronger than the magnetic force of the magnet 3523b of the movable member 3502. That is, even if the probe 26 is pressed by the work W and moves greatly and the movable member 3502 falls off from the non-movable member 3501, the metal ball 3514b is held by the magnet 3513b of the non-movable member 3501.

Here, among the three support portions, the support portion composed of the magnet 3513b of the non-movable member 3501, the metal ball 3514b, and the magnet 3523b of the movable member 3502 is shown, but the other two support portions are also the same. It is configured in. That is, the other support portion is composed of the magnet 3513a of the non-movable member 3501, the metal ball 3514a, and the magnet 3523a of the movable member 3502 (FIG. 43). Yet another support portion is composed of a magnet 3513c of the non-movable member 3501, a metal ball 3514c, and a magnet 3523c of the movable member 3502 (FIG. 43). The shape of each magnet is cylindrical, but other shapes such as a rectangular parallelepiped may be used, but the cylindrical shape is preferable from the viewpoint of ease of processing the support hole.

FIG. 41 shows that the contact portion 261 is in contact with the work W, and the contact portion 261 is moved in the direction of the arrow A1 by the work W. Here, the direction of the arrow A1 is parallel to the y-axis direction. The three metal balls 3514a, 3514b, and 3514c described above are equidistant from each other. That is, the metal spheres 3514a, 3514b, 3514c are on a virtual sphere. Further, among the inner surfaces of the movable member 3502, the contact surfaces that come into contact with the three metal balls 3514a, 3514b, and 3514c are part of the same spherical surface. However, when the radii of the metal spheres 3514a, 3514b, 3514c are different, the contact surfaces in contact with the three metal spheres 3514a, 3514b, 3514c among the inner surfaces of the movable member 3502 are part of a spherical surface having the same center (different radii). Is. Of the contact surfaces of the non-movable member 3501, the contact surfaces that come into contact with the three metal balls 3514a, 3514b, and 3514c are part of the same spherical surface. However, when the radii of the metal spheres 3514a, 3514b, 3514c are different, the contact surfaces in contact with the three metal spheres 3514a, 3514b, 3514c among the contact surfaces of the non-movable member 3501 are spherical surfaces having the same center (different radii). It is a part. Therefore, the movable member 3502 moves in the direction of arrow A2 along this virtual spherical surface. In other words, the contact point of the magnet 3513a with the metal sphere 3514a and the contact point of the magnet 3523a with the metal sphere 3514a are on a sphere having the same center and different radii. .. Similarly, the contact point of the magnet 3513b with the metal sphere 3514b and the contact point of the magnet 3523b with the metal sphere 3514b are on a spherical surface having the same center and different radii. The contact point of the magnet 3513c with the metal ball 3514c and the contact point of the magnet 3523c with the metal ball 3514c are on a spherical surface having the same center and different radii. As a result, the probe 26 and the movable member 3502 move smoothly when the contact portion 261 is pressed against the work W. Further, when the pressing force from the work W is released, the probe 26 and the movable member 3502 smoothly return to their original positions (initial positions). The restoring force (urging force) for this return is realized by the magnetic force of the magnets 3513a, 3513b, 3513c, 3523a, 3523b, 3523c.

FIG. 42 shows that the contact portion 261 came into contact with the work W, and the contact portion 261 was moved in the direction of arrow A3 by the work W. The direction of the arrow A3 is parallel to the y-axis direction. In this case, the movable member 3502 moves in the direction of arrow A4 along the virtual sphere. When the pressing force from the work W is released, the probe 26 and the movable member 3502 smoothly return to the initial positions.

FIGS. 43 (a) to 43 (c) show that a pressing force is applied from the work W to the contact portion 261 in a direction parallel to the zx plane. FIG. 43A shows that the probe 26 and the movable member 3502 are stationary at the initial positions. 43 (b) and 43 (c) show that the movable member 3502 is rotating in the direction indicated by the arrow A6 because the contact portion 261 is pressed in the direction indicated by the arrow A5. When the pressing force on the contact portion 261 is released, the probe 26 and the movable member 3502 return to their initial positions due to the attractive force between the two magnets arranged opposite to each other. The movable member 3502 is supported at three points by the three metal balls 3514a, 3514b, and 3514c with respect to the non-movable member 3501. Therefore, the posture of the movable member 3502 is stably maintained. Further, since the metal spheres 3514a, 3514b, and 3514c are spheres and are arranged along the same virtual spherical surface, the movable member 3502 rotates smoothly.

44 (a) and 44 (b) are schematic cross-sectional views for explaining the mechanism for preventing the metal ball from falling off in more detail. As shown in FIG. 44A, a magnet 3523b is fixed to a cylindrical hole 3521b provided in the housing of the movable member 3502 with an adhesive or the like. Similarly, a magnet 3513b is fixed to a cylindrical hole 3512b provided in the housing of the non-movable member 3501 with an adhesive or the like. A cylindrical hole 3512b'having a radius larger than the radius of the hole 3512b is provided near the upper portion of the hole 3512b. A metal ball 3514b is provided in the hole 3512b'. Since the radius of the hole 3512b'is larger than the radius of the metal sphere 3514b, the metal sphere 3514b can roll and move inside the hole 3512b'. As shown in FIG. 44 (b), when the magnet 3523b of the movable member 3502 moves to the right with the movement of the contact portion 261, the metal ball 3514b also moves to the right. When the metal ball 3514b collides with the inner wall of the hole 3512b', it stops there. Even if the magnet 3523b moves further to the right, the metal ball 3514b cannot advance any further. Further, since the metal ball 3514b is attracted to the magnet 3513b provided on the non-movable member 3501, even if the movable member 3502 falls off from the non-movable member 3501, the metal ball 3514b is held in the hole 3512b'. The material of the housing of the non-movable member 3501 and the housing of the movable member 3502 is a non-magnetic material (example: aluminum) or the like.

In the above embodiment, the movable member 3502 is supported by the non-movable member 3501 by the three metal balls 3514a, 3514b, 3514c. However, the contact surface of the movable member 3502 and the contact surface of the non-movable member 3501 may be slidably in contact with each other without a metal ball. As shown in FIG. 45A, the contact surface 3516 of the non-movable member 3501 functions as a sliding surface. As shown in FIGS. 45 (b) and 45 (c), the contact surface 3526 of the movable member 3502, which faces the contact surface 3516 of the non-movable member 3501, also functions as a sliding surface. At least one of these sliding surfaces may be made of a low friction member such as polyoxymethylene, or may be processed for low friction such as polytetrafluoroethylene plating. The contact surface 3516 of the non-movable member 3501 is a part of the sphere of the sphere having the first radius, and the contact surface 3526 of the movable member 3502 is a part of the sphere of the sphere having the second radius. The centers of these spheres are aligned and the second radius is about the same as or slightly larger than the first radius to achieve smooth sliding. By making these contact surfaces spherical, the movable member 3502 can follow the movement regardless of the direction in which the contact portion 261 moves.

The restoring force for maintaining and returning the movable member 3502 to the initial position is also realized by the magnet in this modified example. As shown in FIG. 45 (b), a gap is provided between the magnet 3513b and the magnet 3523b. Although the pair of the magnet 3513a and the magnet 3523a and the pair of the magnet 3513c and the magnet 3523c are not shown, the same gap is provided for these magnet pairs. By providing these gaps, the movable member 3502 can easily start moving when the contact portion 261 is pushed by the work W. The gap length is determined depending on the magnetic force of each magnet and the weight of the movable member 3502, and is set so that the movable member 3502 does not easily fall off from the non-movable member 3501.

In the above embodiment, the movable member 3502 is maintained and restored to the initial position by the magnet. However, other restoration and support mechanisms may be employed. FIG. 46 shows another support mechanism 3500'. In the support mechanism 3500', three elastic members 4501a, 4501b and 4501c are provided instead of the magnet. The three elastic members 4501a, 4501b, and 4501c are elastic bodies (biasing means) such as rubber and springs. Since the shaft holding member 3524 extends in the y-axis direction, the three elastic members 4501a, 4501b, and 4501c are arranged in a plane parallel to the zx plane. That is, the length directions of the three elastic members 4501a, 4501b, and 4501c are parallel to the zx plane. The length directions of the three elastic members 4501a, 4501b, and 4501c are different by 120 degrees. As a result, the shaft holding member 3524 can be maintained in the initial position and restored to the initial position. One end of each of the three elastic members 4501a, 4501b, 4501c is fixed to the shaft holding member 3524, and the other end of each is fixed to the frame 3550 or the like. Therefore, the movable member 3502 is pressed against the non-movable member 3501 through the shaft holding member 3524. The contact surface of the movable member 3502 and the contact surface of the non-movable member 3501 may be formed as sliding surfaces, respectively. An elastic member that urges the shaft holding member 3524 or the movable member 3502 may be further added so that the movable member 3502 is pressed against the non-movable member 3501.

<Summary>
The image measuring device 1 is placed on the stage 23 on which the work W is mounted, the imaging unit 201 that captures the work W mounted on the stage 23 to generate an image, and the stage 23 within the field of view of the imaging unit 201. A probe 26 having a contact portion 261 that can contact the side surface of the mounted work W, and a horizontal drive portion 24 that moves at least one of the stage 23 and the probe 26 substantially parallel to the mounting surface of the stage 23. Have. In particular, the probe 26 has an inflexible shaft (metal tube 262) with a contact portion 261 fixed at one end. At least part of the shaft extends vertically. The shaft may be a high-rigidity tube and may not necessarily be made of metal. The shaft may be bent in a substantially L shape. Further, the image measuring device 1 uses the image generated by the imaging unit 201 when the support mechanism 3500 that supports the probe 26 and the contact portion 261 and the side surface of the work W come into contact with each other to determine the position of the side surface of the work W. It has a measuring unit (measurement control unit 315) for measuring. As shown in FIG. 35 and the like, the support mechanism 3500 holds a shaft (example: metal tube 262) and is movable together with the shaft (example: movable member 3502) and a fixed portion provided so as to face the movable portion. It has a portion (eg, non-movable member 3501) and an urging mechanism (eg, magnet, elastic member, etc.). The urging mechanism urges the movable portion so that the movable portion and the fixed portion come into contact with each other at at least three points (three places). It is desirable that the positions of the three points are on the same spherical surface, but if the movable part can move smoothly with respect to the non-movable part, the positions of the three points (three contact parts) are the same. It does not have to be in the position on the spherical surface of. By the way, when the contact portion 261 is pressed against the side surface of the work W, the movable portion may move together with the shaft. When the pressing force from the work W on the contact portion 261 is released, the urging mechanism urges the movable portion so that the movable portion returns to the initial position. Since the contact portion 261 is held by the non-flexible shaft in this way, the contact portion 261 is less susceptible to vibration. This contributes to the improvement of measurement accuracy. Further, the contact portion 261 is supported by a movable portion via a shaft. Therefore, even if it comes into contact with the work W, the contact portion 261 also moves following the work W, so that it is difficult for the contact portion 261 to move the work W on the stage 23. As described above, a probe support mechanism capable of suppressing a decrease in measurement accuracy is provided.

The distance between at least three points where the movable portion and the fixed portion come into contact with each other may be equidistant. As a result, the fixed portion can support the movable portion in a well-balanced manner.

As shown in FIG. 39 and the like, the non-movable member 3501 that functions as a fixed portion has a first facing surface that faces the movable portion (movable member 3502). A first magnet group may be provided at three points on the first facing surface. The first magnet group includes magnets 3513a, 3513b, 3513c. Further, the non-movable member 3501 may include ferromagnetic metal spheres 3514a, 3514b and 3514c as three spheres attracted to the first magnet group. As shown in FIG. 43 and the like, the movable member 3502 that functions as a movable portion is provided on the second facing surface facing the fixed portion (non-movable member 3501) so as to attract the first magnet group at the above three points. It may have a second magnet group. The second magnet group may include magnets 3523a, 3523b, 3523c. The urging mechanism is composed of a first magnet group and a second magnet group. This makes the urging mechanism almost maintenance-free and improves usability. Further, the attractive force acting between the first magnet group and the second magnet group generates a restoring force for returning the movable portion to the initial position. Further, when a large force exceeding this attractive force momentarily acts on the contact portion 261, the movable portion is detached from the fixed portion, so that the contact portion 261 and the shaft are less likely to be damaged. Even if the movable portion comes off from the fixed portion, the user can re-adsorb the movable portion to the fixed portion by correcting the position of the movable portion again by holding the shaft by hand. This is because the movable portion is urged to the fixed portion by the attractive force acting between the first magnet group and the second magnet group.

The fixed portion and the movable portion may be in contact with each other at multiple points (eg, surface contact). As shown in FIG. 45, the fixed portion (non-movable member 3501) faces the movable portion (movable member 3502) and slides on the movable portion (movable member 3502) first sliding surface (contact surface 3516). May have. Further, even if the movable portion (movable member 3502) has a second sliding surface (contact surface 3526) that faces the first sliding surface of the fixed portion (non-movable member 3501) and slides. Good. The movable portion may come into contact with the fixed portion and be supported by such surface contact. This brings manufacturing advantages such as the elimination of metal balls 3514a, 3514b, 3514c. The first sliding surface (contact surface 3516) is a part of the first spherical surface, the second sliding surface (contact surface 3526) is a part of the second spherical surface, and the center and the second of the first spherical surface. It may be the same as the center of the sphere. As a result, the movable portion can easily move in any direction, and the pressing force acting on the contact portion 261 can be easily released. As shown in FIG. 45, the fixed portion (non-movable member 3501) has a first magnet group, and the movable portion (movable member 3502) attracts the first magnet group of the fixed portion (non-movable member 3501). It may have a second magnet group arranged in such a manner. As described above, the urging mechanism may be realized by a magnet in the surface contact type as well as the three-point contact type. This makes it easier to apply the necessary and sufficient restoring force to the moving parts.

As shown in FIG. 46, the urging mechanism maintains the first elastic body for urging the movable portion (movable member 3502) to the fixed portion (non-movable member 3501) and the movable portion (movable member 3502) in the initial positions. It may have a second elastic body that urges it to do so. In FIG. 46, the elastic members 4501a, 4501b, 4501c function as the first elastic body and the second elastic body. Of course, in addition to the elastic members 4501a, 4501b, 4501c, a first elastic body that urges the movable portion to the fixed portion may be added.

As shown in FIG. 36 and the like, the movable portion (movable member 3502) may have a shaft holding member 3524 as a rod through which the shaft communicates. The shaft (metal tube 262) may be hollow. An optical fiber 3522 may be provided in the hollow portion of the shaft (metal tube 262) as a light guide member that guides the light from the light source 3560 to the contact portion 261. As shown in FIG. 35, the light source 3560 and the fixed portion (non-movable member 3501) are fixed to the frame 3550. A space may exist between the end of the rod (shaft holding member 3524) into which the light from the light source 3560 is incident and the light source 3560. The light emitted from the light source 3560 propagates in space, enters the optical fiber 3522 from the light incident end, and finally propagates to the contact portion 261 to cause the contact portion 261 to emit light. In particular, it is possible to provide a space between the light source 3560 and the light incident end of the optical fiber 3522, and the movable member 3502 can be moved. This eliminates the need to directly couple the light source 3560 to the optical fiber 3522. On the other hand, a configuration in which the light source 3560 is directly connected to the optical fiber 3522 can also be adopted, but in this configuration, a mechanism for moving the light source 3560 together with the movable member 3502 will be required. Further, since the weight of the movable member 3502 increases, the contact portion 261 becomes difficult to move, and the work W is easily pushed. In contrast to this configuration, a configuration in which a movable space is provided between the incident end of the optical fiber 3522 and the light source 3560 is advantageous.

The difference between the amount of light output from the light source 3560 when the movable portion (movable member 3502) is in the initial position and the amount of light incident from the end portion and reaching the contact portion 261 is minimized. Therefore, by maintaining the movable portion in the initial position by the urging mechanism, it is possible to efficiently make the contact portion 261 emit light.

The longitudinal elastic modulus (Young's modulus) of the shaft (metal tube 262) may be 20 GPa or more. As a result, the contact portion 261 is less likely to vibrate. The longitudinal elastic modulus (Young's modulus) E was obtained so as to satisfy the following equation.

L ³ / (E × I) <0.1
L is the total length of the metal tube 262. I is the moment of inertia of area of the metal tube 262. This equation can be derived from the equation for the amount of deformation of pipe bending due to strength of materials.

By the way, the contact point between the fixed portion and the movable portion may be a part of a surface composed of a set of points equidistant from any one point. Further, the number of the above-mentioned magnet pairs may be 4 or more. The position and orientation of one magnet and the position and orientation of the other magnet that make up the magnet pair are determined so that the vector of the magnetic field created by the north pole of one magnet and the south pole of the other magnet intersects at one point. Will be done. Further, the plurality of magnets provided in the fixed portion may be arranged at positions equidistant from any one point. Similarly, a plurality of magnets provided on the movable portion may be arranged at positions equidistant from any one point. Here, one point of the fixed portion and one point of the movable portion may be the same point. That is, the magnet group of the fixed portion and the magnet group of the movable portion can be arranged on the surfaces (spherical surfaces) of the two concentric spheres. These arrangements would be advantageous for urging the movable portion with respect to the fixed portion and for the movable portion to smoothly follow the movement of the contact portion 261.

1 Image measuring device, 201, 206 imaging unit, 21 display unit, 23 stages, 24 horizontal drive unit, 26 probe, 261 contact unit, 31 control device, 311 input reception unit, 315 measurement control unit, 3500 support mechanism, 3501 non Movable member, 3502 Movable member, 3513b, 3523b Magnet

Claims (11)

The stage on which the work is placed and
An imaging unit that images the work placed on the stage and generates an image,
In the field of view of the imaging unit, a contact portion that can contact the side surface of the work mounted on the stage, and an inflexible shaft in which the contact portion is fixed at one end and at least a part extends in the vertical direction. With a probe that has
A drive unit that moves at least one of the stage and the probe substantially parallel to the mounting surface of the stage.
A support mechanism that supports the probe and
An image measuring device including a measuring unit that measures the position of a side surface of the work using an image generated by the imaging unit when the contact unit and the side surface of the work come into contact with each other.
The support mechanism
A movable part that holds the shaft and moves together with the shaft,
A fixed portion provided facing the movable portion and a fixed portion
An urging mechanism that urges the movable portion so that the movable portion and the fixed portion come into contact with each other at at least three points. When the contact portion is pressed against the side surface of the work, the movable portion is combined with the shaft. Has an urging mechanism that urges the movable portion to be restored to the initial position when it moves from the initial position.
An image measuring device characterized in that the positions of the three points are positions on the same spherical surface. The image measuring device according to claim 1, wherein the shaft is bent in a substantially L shape. The image measuring device according to claim 1 or 2, wherein the distances between the three points are equidistant, respectively. The fixed part is
The first magnet group provided at the three points on the first facing surface facing the movable portion, and
It has three spheres that are attracted to the first magnet group.
The movable part is
It has a second magnet group provided on a second facing surface facing the fixed portion so as to attract the first magnet group at the three points.
The image measuring device according to any one of claims 1 to 3, wherein the urging mechanism is composed of the first magnet group and the second magnet group. The fixed portion has a first sliding surface that faces the movable portion and slides on the movable portion.
The image according to any one of claims 1 to 3, wherein the movable portion has a second sliding surface that faces the first sliding surface of the fixed portion and slides. measuring device. The first sliding surface is a part of the first spherical surface.
The second sliding surface is a part of the second spherical surface.
The image measuring apparatus according to claim 5, wherein the center of the first spherical surface and the center of the second spherical surface are the same. The fixed portion has a first magnet group and has a first magnet group.
The image measuring apparatus according to claim 6, wherein the movable portion has a second magnet group arranged so as to attract the first magnet group of the fixed portion. The urging mechanism
A first elastic body that urges the movable portion to the fixed portion,
The image measuring apparatus according to claim 1, further comprising a second elastic body that urges the movable portion to be maintained at the initial position. The movable portion has a rod with which the shaft communicates.
According to any one of claims 1 to 8, the shaft is hollow, and the hollow portion of the shaft is provided with a light guide member that guides light from a light source to the contact portion. The image measuring device described. The light source and the fixed portion are fixed to the frame and
A space exists between the end of the rod on which the light from the light source is incident and the light source, and the amount of light output from the light source when the movable portion is in the initial position and the said. The image measuring apparatus according to claim 9, wherein the difference from the amount of light incident from the end portion and reaching the contact portion is minimized. The image measuring apparatus according to any one of claims 1 to 10, wherein the Young's modulus of the shaft is 20 GPa or more.