JP6184345B2 - Image measuring instrument - Google Patents

Description

  The present invention relates to an image measuring instrument, and more particularly, to an improvement of an image measuring instrument that extracts an edge in a workpiece image obtained by photographing a workpiece and measures the size and shape of the workpiece.

  An image measuring device is a device that captures a workpiece, acquires the workpiece image, extracts an edge in the workpiece image, and measures the size and shape of the workpiece (for example, Patent Documents 1 to 5). Usually, the workpiece is placed on a movable stage movable in the X, Y and Z axis directions. The workpiece image is focused by moving the movable stage in the Z-axis direction, and the position of the workpiece in the visual field is adjusted by moving in the X- or Y-axis direction.

  Since the workpiece image is a very accurate similar shape to the workpiece regardless of the position of the movable stage in the Z-axis direction, the actual dimensions on the workpiece can be determined by determining the distance and angle on the workpiece image. Can be detected. Edge extraction is a method of analyzing the brightness change of a workpiece image area specified in advance to extract edge points and fitting a plurality of extracted edge points with geometric figures such as straight lines, circles, and arcs. Is done. The dimensions of the workpiece are measured as the distance and angle between the edges determined in this way, and the center position and diameter of the circular edge. In addition, a quality determination is performed by comparing a difference (error) between the measured dimension value and the design value with a tolerance.

  When measuring the external shape of a workpiece using such an image measuring device, transmitted illumination that irradiates illumination light to the workpiece on the stage from the opposite side of the camera is often used. On the other hand, when measuring a non-through hole, a step, and an unevenness on a workpiece, epi-illumination that illuminates the workpiece on the stage from the same side as the camera is used.

JP 2012-32224 A JP 2012-32341 A JP 2012-32344 A JP 2012-159409 A JP 2012-159410 A

  In a conventional image measuring device, it is necessary to appropriately specify a measurement target region for a work image in order to correctly extract a desired edge. However, it is not easy to specify the position and shape of the measurement target region in addition to the time-consuming work for the user, and it is easy to determine the position of the measurement target region so that the edge to be extracted is included. There was no problem. In particular, in workpiece images shot using epi-illumination, it is easy to misidentify textures on the workpiece surface, that is, processing traces, patterns, fine irregularities, steps, etc., as edges and accurately identify the desired edge. There was a problem that was difficult.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an image measuring instrument that can correctly extract a desired edge without increasing a user's work load. In particular, even if there is a variation in position in the measurement target region specified by the user, the measurement target region is specified incorrectly, or even if a plurality of edges are included in the measurement target region, the desired region An object of the present invention is to provide an image measuring device capable of correctly extracting edges.

  An image measuring instrument according to a first aspect of the present invention includes a camera that captures a workpiece and generates a workpiece image, a measurement region designation unit that designates a measurement target region for the workpiece image based on a user operation, and the measurement Any one of the edge extraction results based on a user operation, an edge extraction means for extracting edges in the target area, an edge extraction result display means for displaying two or more edge extraction results for the same measurement target area Edge extraction result selection means for selecting the edge extraction parameter determination means for determining an edge extraction parameter for preferentially extracting the selected edge extraction result over the other edge extraction results. The

  In this image measuring device, two or more edge extraction results extracted from the same measurement target region are displayed. For this reason, the user can determine an edge extraction parameter suitable for extracting a desired edge only by selecting one of the displayed edge extraction results. Further, since the edge extraction is performed based on the edge extraction parameters determined in this way, when there is a variation in position in the measurement target region, when the measurement target region is specified incorrectly, or when a plurality of edges are detected. Even if it is included in the measurement target region, a desired edge can be correctly extracted.

  In addition to the above-described configuration, the image measuring device according to the second aspect of the present invention is configured such that the edge extraction result display means displays the edge extraction result superimposed on the work image. According to such a configuration, the relative positional relationship between the edge extraction result and the work image can be easily identified.

  In addition to the above configuration, the image measuring instrument according to the third aspect of the present invention is configured to measure the edge extraction parameter determined by the edge extraction parameter determination unit and the measurement target region specified by the measurement region specification unit. Measurement setting storage means that holds the edge extraction parameters in association with the measurement target region, and the edge extraction means performs continuous measurement in which the measurement setting data is designated. The edge extraction is performed based on the edge extraction parameters held as the measurement setting data.

  According to such a configuration, since the edge extraction parameter is stored in the measurement setting storage unit in association with the measurement target region, the edge extraction suitable for measuring the measurement target region can be performed by specifying the measurement setting data. Parameters can be identified. In continuous measurement in which measurement setting data is designated, edge extraction is performed with an edge extraction parameter suitable for measuring the measurement target region. Therefore, even if the shape or material of the workpiece changes, stable dimension measurement can be performed simply by specifying measurement setting data.

  In addition to the above-described configuration, the image measuring device according to the fourth aspect of the present invention includes, in the measurement setting storage unit, two or more measurement target regions designated for the same workpiece image by the measurement region designation unit, and these The edge extraction parameter determined by the edge extraction parameter determination unit for each measurement target area is stored as measurement setting data, and the edge extraction unit is configured to store the edge held as the measurement setting data in the continuous measurement. Extracting an edge from the corresponding measurement target region using the extraction parameter is configured to be repeated while changing the measurement target region. According to such a configuration, it is possible to perform stable dimension measurement for a plurality of measurement target regions simply by specifying measurement setting data.

  In addition to the above-described configuration, the image measuring instrument according to the fifth aspect of the invention is configured such that the edge extraction result display means selectively displays any one of two or more edges extracted from the same measurement target region. Composed. According to such a configuration, the edges extracted from the same measurement target region can be individually confirmed.

  In addition to the above-described configuration, the image measuring instrument according to the sixth aspect of the present invention includes a dimension value calculating means for obtaining a dimension value of a workpiece based on the extracted edge, and a geometric feature based on the extracted edge. A geometric feature amount calculating means for obtaining a quantity, and the edge extraction result display means displays the dimension value, the edge point sequence constituting the edge, or the geometric feature quantity in association with the edge. Configured to do. According to such a configuration, the shape and position of the edge can be confirmed, and the edge point sequence constituting the edge, the dimensional value of the workpiece obtained from the edge, or the geometric feature amount can be confirmed appropriately. Edges can be selected.

  An image measuring device according to a seventh aspect of the present invention includes, in addition to the above configuration, an edge shape designating unit that designates an edge shape based on a user operation, and the edge extracting unit is based on the designated edge shape, An edge in the measurement target region is extracted. According to such a configuration, since an edge having a shape other than the edge shape designated by the user is not extracted, the accuracy of edge extraction can be improved.

  In addition to the above-described configuration, the image measuring device according to the eighth aspect of the present invention is a geometrical structure in which the edge shape designating means fits an edge point sequence based on region designation information when the user designates the measurement target region. It is configured to automatically determine the shape. According to such a configuration, the edge shape can be designated simply by designating the measurement target region.

  An image measuring device according to a ninth aspect of the present invention comprises, in addition to the above-described configuration, a stability calculation unit that obtains the stability of edge extraction for two or more edges extracted from the same measurement target region, and the edge extraction result The display means is configured to selectively display two or more edges extracted from the same measurement target region based on the stability. According to such a configuration, since the edge with low stability is not displayed, it is possible to prevent the edge extraction parameter from being erroneously determined by the edge with low stability.

  An image measuring instrument according to a tenth aspect of the present invention, in addition to the above configuration, the edge extraction means repeats edge extraction while changing the edge extraction parameter for extracting only one edge for the same measurement target region. Thus, a plurality of edges are extracted. According to such a configuration, it is possible to extract a plurality of edges from the same measurement target region only by changing the edge extraction parameters.

  An image measuring instrument according to an eleventh aspect of the present invention, in addition to the above-described configuration, includes the edge extraction parameter determination means when the edge extraction means repeats edge extraction while changing the edge extraction parameters to extract a plurality of edges. Are configured to simultaneously determine the edge extraction parameters. According to such a configuration, when a plurality of edges are extracted from the same measurement target region, an edge extraction parameter suitable for extracting each edge is automatically determined, and the user selects an edge. At this point, it is not necessary to obtain edge extraction parameters by calculation.

  An image measuring device according to a twelfth aspect of the present invention is the image measuring device according to the present invention, wherein the edge extracting means groups a plurality of edge points extracted from the measurement target region into two or more shape groups according to the geometric figure to be fitted. The edge is divided and specified for each shape group. According to such a configuration, it is possible to extract a plurality of edges from the same measurement target region by grouping a large number of edge points into a plurality of shape groups.

  An image measuring device according to a thirteenth aspect of the present invention includes, in addition to the above configuration, user notification means for notifying a user that two or more of the edges have been extracted from the same measurement target region, and the edge extraction result display means includes Based on the user operation, two or more edges extracted from the same measurement target region are displayed on the work image. According to such a configuration, after confirming that a plurality of edges are extracted from the same measurement target region, these edges can be displayed on the work image.

  ADVANTAGE OF THE INVENTION According to this invention, the image measuring device which can extract a desired edge correctly can be provided, without increasing a user's workload. In particular, since multiple edge extraction results are extracted from the same measurement target area and the edge extraction parameters are determined, even if there is a variation in position in the measurement target area specified by the user, the desired edge can be correctly extracted. It is possible to provide an image measuring device that can

It is the perspective view which showed one structural example of the image measuring device 1 by Embodiment 1 of this invention. It is explanatory drawing which showed typically the structural example of the measurement unit 10 of FIG. 1, and the cut surface at the time of cut | disconnecting the measurement unit 10 by the perpendicular | vertical surface parallel to an imaging | photography axis | shaft is shown. It is the block diagram which showed an example of the function structure in the control unit 20 of FIG. FIG. 2 is a diagram showing an example of the operation of the image measuring device 1 in FIG. 1, and shows a measurement setting screen 50 displayed on the display device 11 of the measurement unit 10. FIG. 2 is a diagram showing an example of the operation of the image measuring device 1 in FIG. 1, and shows a state after a measurement target region 3 is designated for a work image 2 in a preview region 51. FIG. 2 is a diagram showing an example of the operation of the image measuring device 1 in FIG. 1, and shows a case where one of the edges 4 extracted from the measurement target region 3 is selected. FIG. 8 is a diagram showing an example of the operation of the image measuring device 1 in FIG. 1, and shows a case where another edge 4 is selected by operating the edge selection button 56. It is explanatory drawing which showed typically an example of the operation | movement at the time of edge extraction in the image measuring device 1 of FIG. It is the figure which showed an example of the operation | movement at the time of the edge extraction in the image measuring device 1 of FIG. 1, and the edge point 5 extracted by changing edge extraction parameters mutually is shown. 3 is a flowchart showing an example of an operation at the time of measurement setting in the image measuring device 1 of FIG. 1. 3 is a flowchart showing an example of an operation at the time of dimension measurement in the image measuring device 1 of FIG. 1. FIG. 5 is a block diagram showing an example of the configuration of an image measuring device 1 according to Embodiment 2 of the present invention, in which an example of a functional configuration in the control unit 20 is shown.

Embodiment 1 FIG.
<Image measuring device 1>
FIG. 1 is a perspective view showing a configuration example of an image measuring device 1 according to Embodiment 1 of the present invention. The image measuring instrument 1 is a dimension measuring apparatus that extracts an edge in a workpiece image obtained by photographing a workpiece and measures the dimension of the workpiece, and includes a measuring unit 10, a control unit 20, a keyboard 31, and a mouse 32. The workpiece is a measurement object whose shape and dimensions are measured.

  The measurement unit 10 includes a display device 11, a movable stage 12, an XY adjustment knob 14 a, a Z adjustment knob 14 b, a power switch 15, and an execution button 16, and irradiates the work on the movable stage 12 with detection light composed of visible light, The transmitted light or reflected light is received to generate a work image. The workpiece is placed in the detection area 13 of the movable stage 12. Further, the measurement unit 10 displays the work image on the display screen 11 a of the display device 11.

  The display device 11 is a display device that displays work images and measurement results on the display screen 11a. The movable stage 12 is a mounting table for mounting a work, and is provided with a detection area 13 through which detection light is transmitted. The detection area 13 is a circular area made of transparent glass. The movable stage 12 can be moved in the Z-axis direction parallel to the shooting axis of the camera and in the X-axis direction and the Y-axis direction perpendicular to the shooting axis.

  The XY adjustment knob 14a is an operation unit for adjusting the position in the X-axis direction and the Y-axis direction by moving the movable stage 12 in the X-axis direction or the Y-axis direction. The Z adjustment knob 14b is an operation unit for adjusting the position in the Z-axis direction by moving the movable stage 12 in the Z-axis direction. The power switch 15 is an operation unit for switching the main power supply of the measurement unit 10 and the control unit 20 between an on state and an off state. The execution button 16 is an operation unit for starting dimension measurement.

  The control unit 20 is a controller unit that controls photographing and screen display by the measurement unit 10, analyzes a work image, and measures the dimensions of the work, and is connected to a keyboard 31 and a mouse 32. After the power is turned on, if the work is placed in the detection area 13 and the execution button 16 is operated, the dimensions of the work are automatically measured.

<Measurement unit 10>
FIG. 2 is an explanatory view schematically showing a configuration example of the measurement unit 10 of FIG. 1, and shows a cut surface when the measurement unit 10 is cut by a vertical plane parallel to the imaging axis. The measurement unit 10 includes a display device 11, a movable stage 12, a housing 100, a stage adjustment unit 101, a lens barrel unit 102, an illumination position adjustment unit 103, cameras 110 and 120, a coaxial incident illumination unit 130, a ring illumination unit 140, and The transmitted illumination unit 150 is used.

  The stage adjustment unit 101, the lens barrel unit 102, the cameras 110 and 120, the coaxial incident illumination unit 130, and the transmission illumination unit 150 are disposed in the housing 100. The stage adjustment unit 101 moves the movable stage 12 in the X, Y, or Z axis direction based on the drive signal from the control unit 20 to adjust the position of the workpiece in the X, Y, and Z axis directions.

  The camera 110 is an imaging device with a low imaging magnification, and includes an imaging element 111, an imaging lens 112, a diaphragm plate 113, and a light receiving lens 114. The image sensor 111 receives the detection light and generates a work image. The image sensor 111 is disposed with the light receiving surface facing downward. The imaging lens 112 is an optical member that images the detection light on the image sensor 111. The diaphragm plate 113 is an optical diaphragm that limits the amount of transmitted detection light, and is disposed between the imaging lens 112 and the light receiving lens 114. The light receiving lens 114 is an optical member that condenses the detection light from the workpiece, and is disposed to face the movable stage 12. The imaging lens 112, the diaphragm plate 113, and the light receiving lens 114 are arranged around a central axis extending in the vertical direction.

  The camera 120 is an imaging device having a high shooting magnification, and includes an imaging device 121, an imaging lens 122, a diaphragm plate 123, a half mirror 124, and a light receiving lens 114. The image sensor 121 receives the detection light and generates a work image. The image sensor 121 is disposed with the light receiving surface facing in the horizontal direction. The imaging lens 122 is an optical member that images the detection light on the image sensor 121. The diaphragm plate 123 is an optical diaphragm that limits the amount of detection light transmitted, and is disposed between the imaging lens 122 and the half mirror 124. The light receiving lens 114 is common to the camera 110. The detection light transmitted through the light receiving lens 114 is bent in the horizontal direction by the half mirror 124 and forms an image on the image sensor 121 through the diaphragm plate 123 and the imaging lens 122.

  For the imaging elements 111 and 121, an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) is used. As the light receiving lens 114, a telecentric lens having a property that the size of the image is not changed even if the position in the vertical direction, that is, the photographing axis direction is changed, is used.

  The coaxial epi-illumination unit 130 is an epi-illumination device that irradiates the workpiece on the movable stage 12 with illumination light from above, and makes the optical axis of the illumination light coincide with the imaging axis. The coaxial incident illumination unit 130 includes a light source 131 arranged in the horizontal direction and a half mirror 132 that bends the illumination light emitted from the light source 131 downward.

  The imaging lenses 112 and 122, the diaphragm plates 113 and 123, the half mirrors 124 and 132, and the light receiving lens 114 are disposed in the lens barrel portion 102.

  The transmission illumination unit 150 is a transmission illumination device that irradiates the work on the movable stage 12 with illumination light from below, and includes a light source 151, a mirror 152, and a condenser lens 153. The light source 151 is arranged in the horizontal direction. The illumination light emitted from the light source 151 is reflected by the mirror 152 and emitted through the condenser lens 153. The illumination light is transmitted through the movable stage 12, a part of the transmitted light is blocked by the work, and the other part is incident on the light receiving lens 114.

  The ring illumination unit 140 is an epi-illumination device that irradiates the workpiece on the movable stage 12 with illumination light from above or from the side, and has a ring shape that surrounds the imaging axes of the cameras 110 and 120. The ring illumination unit 140 includes a diffuse illumination device 141 that irradiates the workpiece on the movable stage 12 from above or from the side, and a side illumination device 142 that illuminates the workpiece on the movable stage 12 from the side. Is an illuminating device arranged coaxially.

  The diffuse illumination device 141 includes a ring-shaped light source that surrounds the imaging axes of the cameras 110 and 120. This light source can be turned on every two or more blocks divided in the circumferential direction. The side illuminating device 142 can irradiate parallel light or illumination light having a divergence angle close to parallel light to illuminate the periphery of the workpiece from the side.

  An LED (light emitting diode) or a halogen lamp is used as a light source of the illumination units 130 to 150. The illumination position adjustment unit 103 is a relative position adjustment unit that adjusts the relative position of the ring illumination unit 140 with respect to the movable stage 12 by moving the ring illumination unit 140 in the imaging axis direction. As a method for illuminating the workpiece, one of transmission illumination, ring illumination, and coaxial epi-illumination can be selected.

<Control unit 20>
FIG. 3 is a block diagram showing an example of a functional configuration in the control unit 20 of FIG. The control unit 20 includes an imaging control unit 21, a work image storage unit 22, a measurement area designation unit 23, a measurement setting storage unit 24, a geometric feature amount calculation unit 25, an edge extraction unit 26, a dimension value calculation unit 27, an edge The shape specifying unit 28, the edge extraction result display unit 29, the edge extraction result selection unit 30, and the edge extraction parameter determination unit 41 are configured.

  The imaging control unit 21 controls the cameras 110 and 120, the illumination position adjustment unit 103, and the illumination units 130 to 150 based on a user operation, acquires a work image from the camera 110 or 120, and stores it in the work image storage unit 22. Store.

  The measurement area designating unit 23 reads a work image from the work image storage unit 22 based on a user operation, and designates a measurement target area for the work image. The measurement target area is an image area on which edge extraction processing is performed for dimension measurement, and various shapes such as a rectangle, a circle, a ring, and an arc can be designated. For example, the measurement area designating unit 23 designates a measurement target area using a work image photographed by irradiating the diffused light from the diffuse illumination device 141. By using a work image photographed by irradiating diffused light, it is possible to designate a measurement target region while confirming the entire image of the work. The measurement setting storage unit 24 stores position information indicating the measurement target area and measurement type as measurement setting data.

  There are various methods for specifying the measurement target region. For example, when specifying a rectangular area, there are a method in which a rectangular area is selected only by specifying one point on the image, and a method in which a start point, an end point, an area width, or two or more vertices are specified. When a circular area is designated, there are a method for designating one point and a method for designating one point and a radius. In addition, when designating an annular region, there is a method of designating one point, a radius and a region width. In addition, when specifying an arc region, there is a method of specifying a start point, an intermediate point, and an end point. These methods can be arbitrarily selected by the user.

  As a specific method of specifying the position of the point, a method of operating the mouse 32 to move the mouse cursor within the display screen 11a and performing a click operation, and a display device 11 detects a touch operation on the display screen 11a. In the case of having a touch panel function, there are a method of tracing the display screen 11a and a method of tapping. These methods can be arbitrarily selected by the user.

  In addition, in order to extract as many edges as possible from the measurement target region, the configuration is such that a region obtained by enlarging the image region designated by the user on the display screen 11a outward by a certain distance is designated as the measurement target region. There may be.

  The edge extraction unit 26 extracts an edge in the measurement target region. The edge extraction processing is performed by analyzing the luminance change of the pixels in the measurement target area to extract edge points and fitting geometric shapes such as lines, circles, and arcs to the extracted edge points. Is called.

  The dimension value calculation unit 27 obtains the dimension value of the workpiece based on the edge extracted by the edge extraction unit 26 and outputs it as a measurement result. The geometric feature amount calculation unit 25 obtains a geometric feature amount based on the edge extracted by the edge extraction unit 26. The geometric feature amount is a feature amount of a geometric figure fitted to an edge point sequence constituting an edge, and straightness, roundness, position from a reference coordinate, etc. are calculated as a geometric feature amount. .

  The edge extraction result display unit 29 displays two or more edge extraction results for the same measurement target region on the display device 11. In addition to the edge extracted by the edge extraction unit 26, the edge extraction result includes an edge point sequence, a fitting line, a dimension value obtained from the edge, and a geometric feature amount. For example, the edge extraction result display unit 29 reads out and displays the work image from the work image storage unit 22 and displays two or more edge extraction results extracted from the same measurement target region on the work image. .

  There are two methods for displaying multiple edges extracted from the same measurement target area on the work image: a method that displays a list of multiple edges, and a method that selectively displays one of the multiple edges. The user can arbitrarily specify. If a plurality of edges are displayed in a list, the relative positional relationship of each edge can be easily identified. On the other hand, if any one of a plurality of edges is selectively displayed, the edges extracted from the same measurement target region can be individually confirmed.

  Further, the edge extraction result display unit 29 displays the dimension value, the edge point sequence constituting the edge, or the geometric feature amount in association with the edge. By configuring in this way, the shape and position of the edge can be confirmed, and the edge point sequence constituting the edge, the dimensional value of the workpiece obtained from the edge, or the geometric feature amount can be confirmed appropriately. Edges can be selected. The edge extraction result selection unit 30 selects any one of the edge extraction results displayed by the edge extraction result display unit 29 based on a user operation.

  The edge extraction parameter determination unit 41 determines an edge extraction parameter for preferentially extracting the edge extraction result selected by the edge extraction result selection unit 30 over other edge extraction results. The measurement setting storage unit 24 holds the edge extraction parameter determined by the edge extraction parameter determination unit 41 and the measurement target region specified by the measurement region specifying unit 23 as measurement setting data. The measurement setting storage unit 24 stores edge extraction parameters in association with measurement target regions.

  The edge extraction parameter is a variable including two or more extraction conditions for extracting one edge from the measurement target region. The extraction conditions constituting the edge extraction parameters include edge strength, scan direction, edge direction, and priority designation.

  The edge strength is a differential value of the luminance in the luminance distribution composed of the pixel position in the linear direction and the luminance value of each pixel. The upper limit value or lower limit value of the edge strength can be designated as the edge extraction parameter. The edge strength is higher as the pixel position changes rapidly. In addition, at pixel positions with low edge strength, noise components may be erroneously extracted as edges, but stable edge extraction is possible by extracting only edge points within the range specified by the upper and lower limits. Is possible.

  The scan direction is a search direction when searching for an edge, and when viewed from the user, either the left direction or the right direction, or the upward direction or the downward direction is used as an edge extraction parameter with respect to the measurement target region. Can be specified. The edge direction is the direction of luminance change extracted as an edge point. When the luminance distribution is scanned in the scan direction, the luminance value changes from the low luminance side to the high luminance side, or the luminance value is on the high luminance side. It can be specified as an edge extraction parameter whether it changes from low to low luminance side. Usually, since the edge points constituting a specific edge are in the same direction, it is possible to suppress erroneous extraction of edges in the reverse direction by designating the edge direction.

  The priority designation is a designation of which edge point is adopted when two or more edge points satisfying the extraction conditions designated by the parameters of the edge strength, the scanning direction and the edge direction are detected on the same straight line. is there. For example, when scanning the luminance distribution in the scan direction, select whether to use the edge point detected first or the edge point closest to the center or center line of the measurement target area as the edge extraction parameter can do. Further, it is possible to select by priority designation that the luminance distribution is scanned from the side with less noise component and the edge point detected first is adopted. Such priority designation can improve the stability of edge extraction.

  Specific methods of edge extraction include a method for extracting only edges included in the measurement target region, a method for extracting only edges that cross the boundary of the measurement target region, and an edge included in the measurement target region and measurement. There is a method of extracting both the edge crossing the boundary of the target area. These methods can be arbitrarily selected by the user.

  Usually, a combination of a plurality of parameters indicating edge strength and scan direction is designated as the edge extraction parameter so that a desired edge is uniquely extracted. On the other hand, when two or more edges are extracted from the same measurement target region, a method of changing some or all of the edge extraction parameters used at normal time and a part of the edge extraction parameters used at normal time or There are a method of ignoring all parameters and a method of grouping two or more edge points extracted from the measurement target region into two or more groups.

  There is also a method of repeating edge extraction while changing edge extraction parameters. In this case, the edge extraction parameter determination unit 41 determines the edge extraction parameter simultaneously when the edge extraction unit 26 extracts a plurality of edges by repeating edge extraction while changing the edge extraction parameter. The various methods described above can be arbitrarily selected by the user.

  There are various methods for grouping the edge points extracted from the measurement target region into a plurality of groups. For example, there are a method of classifying edge points close to each other into the same group using position information of edge points, and a method of grouping edge points based on edge characteristics, that is, edge direction or edge strength. . There is also a method of grouping edge points based on the order on the scan line when viewed from the scan direction. Further, there is a method of grouping a large number of edge points extracted from the measurement target region into two or more shape groups according to the geometric figure to be fitted. In this method, an edge is specified for each shape group. These methods can be arbitrarily selected by the user.

  The edge shape designation unit 28 designates an edge shape based on a user operation. The edge shape is a geometric shape to be fitted to the edge point sequence, and a straight line, a circle, an arc, or an arbitrary curve can be designated as the edge shape. Specifically, the edge shape is automatically determined based on the area designation information when the user designates the measurement target area. For example, when a measurement target region is specified by a drag operation, the edge shape is determined based on the locus of the mouse cursor at the time of the drag operation. Alternatively, when the positions of three or more points are designated by a click operation, the edge shape is determined based on a point sequence including these points.

  The edge extraction unit 26 extracts an edge in the measurement target region based on the edge shape designated by the edge shape designation unit 28. By configuring in this way, edges having shapes other than the edge shape designated by the user are not extracted, so that the accuracy of edge extraction can be improved.

  Measurement results such as dimension values are displayed on the display device 11. Further, the control unit 20 creates measurement setting data for continuous measurement for continuously measuring the workpiece. The measurement setting data includes positioning information, a measurement target region, and information indicating a design value and tolerance for each measurement target region. The positioning information is information for analyzing the workpiece image and detecting the position and posture of the workpiece.

  The edge extraction unit 26 performs edge extraction based on an edge extraction parameter held as measurement setting data in continuous measurement in which measurement setting data is specified. Further, in the measurement setting storage unit 24, two or more measurement target regions specified for the same work image by the measurement region specifying unit 23, and the edge extraction parameter determination unit 41 determines each of these measurement target regions. The edge extraction parameters are stored as measurement setting data. In the continuous measurement, the edge extraction unit 26 repeats extracting the edge from the corresponding measurement target region using the edge extraction parameter held as the measurement setting data while changing the measurement target region.

  In continuous measurement with measurement setting data specified, edge extraction is performed with edge extraction parameters suitable for measuring the measurement target area, so even if the shape or material of the workpiece changes, only measurement setting data can be specified. Stable dimension measurement can be performed for a plurality of measurement target regions.

<Measurement setting screen 50>
FIG. 4 is a diagram illustrating an example of the operation of the image measuring device 1 of FIG. 1, and shows a measurement setting screen 50 displayed on the display device 11 of the measurement unit 10. The measurement setting screen 50 is an editing screen for setting edge extraction parameters, and includes a preview area 51, a setting procedure display area 52, an edge shape selection button 53, a confirmation button 54, and an OK button 55.

  In the preview area 51, the photographed work image 2 is displayed. In this example, a work image 2 photographed using transmitted illumination is displayed in the preview area 51. The setting procedure display area 52 displays an operation procedure from the specification of the measurement target area to the determination of edge selection. The edge shape selection button 53 is an operation icon for selecting an edge shape and a dimension type. The confirm button 54 is an operation icon for confirming the setting contents and shifting to the next operation procedure. The OK button 55 is an operation icon for determining an edge extraction parameter based on the selected edge.

  FIG. 5 is a diagram showing an example of the operation of the image measuring device 1 of FIG. 1, and shows a state after the measurement target region 3 is designated for the work image 2 in the preview region 51. When a circle is selected as the edge shape to be extracted, an annular region can be designated as the measurement target region 3 by designating three points on the circular contour line in the work image 2. In this example, the measurement target region 3 is specified along a through hole formed in the center of the workpiece.

  FIG. 6 is a diagram showing an example of the operation of the image measuring device 1 of FIG. 1, and shows a case where one of the edges 4 extracted from the measurement target region 3 is selected. FIG. 7 is a diagram showing an example of the operation of the image measuring device 1 in FIG. 1, and shows a case where the other edge 4 is selected by operating the edge selection button 56.

  When a plurality of edges 4 are extracted from the same measurement target area 3, any one of the extracted edges 4 is displayed on the work image 2 in the preview area 51. In the work image 2, dimension values are displayed in association with the edge being displayed. The edge selection button 56 is an operation icon for selecting the edge 4 to be displayed in the preview area 51.

  Each time the edge selection button 56 is operated to change the edge selection, the edge 4 and the dimension value displayed on the work image 2 in the preview area 51 are switched. The user can easily identify a desired edge by confirming the edge 4 and the dimension value displayed on the work image 2.

  FIG. 8 is an explanatory view schematically showing an example of an operation at the time of edge extraction in the image measuring instrument 1 of FIG. In (a) of the figure, a rectangular measurement target region 3 defined on the work image 2 and linear scan lines SL1 and SL2 defined in the measurement target region 3 are shown.

  Edge extraction is performed by analyzing a change in luminance along the scan line SL1 or SL2, and a point where the luminance changes abruptly is extracted as an edge point. Specifically, the luminance change rate, that is, the differential value is the edge strength, and the maximum point of the edge strength is extracted as the edge point.

  (B) in the figure shows an edge intensity distribution composed of edge intensities for each position x on the scan line SL1, and (c) in the figure shows from the edge intensity for each position x on the scan line SL2. An edge intensity distribution is shown.

  On the scan line SL1, there are four change points where the luminance changes greatly, whereas on the scan line SL2, there are two change points where the luminance changes greatly. In this way, the edge intensity distribution varies greatly depending on the position of the scan line SL with respect to the unevenness or level difference on the workpiece surface.

  FIG. 9 is a diagram showing an example of the operation at the time of edge extraction in the image measuring device 1 of FIG. 1, and shows edge points 5 extracted with different edge extraction parameters. In this figure, edge points 5 extracted from the measurement target region 3 on the work image 2 shown in FIG. 8 are shown.

  (A) in the figure shows a case where the edge extraction parameter is specified so that the edge strength maximum point is extracted as the edge point 5. In this case, four edge points 5 are extracted from the scan line SL1, and two edge points 5 are extracted from the scan line SL2. In (a), the right direction is designated as the scan direction.

  (B) in the figure shows the case where the edge extraction parameter is specified so that the first local maximum point in the scanning direction is extracted as the edge point 5 among the local maximum points of the edge intensity. ing. In this case, the edge points 5 extracted from the scan lines SL1 and SL2 differ depending on the scan direction. That is, when the right direction is designated as the scan direction, one edge point 5 is extracted from each of the scan lines SL1 and SL2, and is displayed at a position corresponding to the step at the left end on the workpiece surface.

  On the other hand, when the left direction is designated as the scan direction, the edge point 5 extracted from the scan line SL1 is displayed at a position corresponding to the step on the right end on the workpiece surface, and the edge extracted from the scan line SL2 A point 5 is displayed at a position corresponding to the second step from the left end on the workpiece surface.

  In (c) in the figure, the edge extraction parameter is specified so that the first maximum point in the rank as viewed from the scan direction is extracted as the edge point 5 among the maximum points whose edge strength is greater than the threshold Eth. The case is shown. Also in this case, the edge points 5 extracted from the scan lines SL1 and SL2 differ depending on the scan direction. That is, when the right direction is designated as the scan direction, one edge point 5 is extracted from each of the scan lines SL1 and SL2, and is displayed at a position corresponding to the step at the left end on the workpiece surface.

  On the other hand, when the left direction is designated as the scan direction, one edge point 5 is extracted from each of the scan lines SL1 and SL2 and displayed at a position corresponding to the second step from the left end on the workpiece surface. ing.

  In (d) in the figure, among the maximal points where the edge intensity is larger than the threshold Eth and the edge direction is dark (low luminance side) to bright (high luminance side), the rank is viewed from the scanning direction. The case where the edge extraction parameter is designated so that the first maximum point is extracted as the edge point 5 is shown. Also in this case, the edge points 5 extracted from the scan lines SL1 and SL2 differ depending on the scan direction. That is, when the right direction is designated as the scan direction, one edge point 5 is extracted from each of the scan lines SL1 and SL2, and is displayed at a position corresponding to the second step from the left end on the work surface. .

  On the other hand, when the left direction is designated as the scan direction, one edge point 5 is extracted from each of the scan lines SL1 and SL2, and is displayed at a position corresponding to the left end step on the workpiece surface. In this way, the edge point 5 extracted from the measurement target region 3 can be controlled by adjusting the edge extraction parameter.

  Steps S101 to S110 in FIG. 10 are flowcharts showing an example of an operation at the time of measurement setting in the image measuring device 1 in FIG. First, the control unit 20 receives a user operation, and if a measurement target area is specified for the work image (step S101), the control unit 20 analyzes the luminance change in the measurement target area, extracts an edge, and extracts the extracted edge. Based on this, a dimension value is calculated (step S102).

  Next, when two or more edge extraction results are extracted from the same measurement target region, the control unit 20 selectively displays any one of these edge extraction results (steps S103 and S104). If an edge extraction result is selected by the above, an edge extraction parameter is determined based on the selected edge extraction result and stored as measurement setting data (steps S105 and S106).

  On the other hand, if only one edge extraction result is extracted from the measurement target area, the control unit 20 displays the edge extraction result on the work image, determines the edge extraction parameter based on the edge extraction result, and sets the measurement setting. Store as data (steps S103, S109, S110).

  Next, the control unit 20 repeats the processing procedure after step S101 if there is any other measurement target area designation (step S107), and if there is no other measurement target area designation, creates control setting data. This process ends (step S108).

  Steps S201 to S210 in FIG. 11 are flowcharts showing an example of the operation at the time of dimension measurement in the image measuring device 1 in FIG. First, the control unit 20 receives a user operation and selects measurement setting data corresponding to a workpiece to be continuously measured (step S201).

  Next, when the execution button 16 of the measurement unit 10 is operated (step S202), the control unit 20 reads the measurement target area held as measurement setting data (step S203), and photographs the workpiece on the movable stage 12. Then, a work image is acquired (step S204).

  The control unit 20 extracts an edge of the measurement target area based on the acquired work image (step S205), and calculates a dimension value based on the extracted edge (step S206). If there are other measurement target areas, the control unit 20 repeats the processing procedure from step S203 to step S206 (step S207), and if all the measurement target areas are completed, the edge and dimension values are measured. The result is displayed on the display device 11 (step S208), and the measurement result is stored (step S209).

  If there are other workpieces to be continuously measured, the control unit 20 repeats the processing procedure after step S202, and if there are no other workpieces to be continuously measured, this control process is terminated (step 210).

  According to the present embodiment, since two or more edge extraction results extracted from the same measurement target region are displayed on the work image, the user can select any one of the edge extraction results displayed on the work image. It is possible to determine an edge extraction parameter suitable for extracting a desired edge simply by selecting. Further, since the edge extraction is performed based on the edge extraction parameters determined in this way, when there is a variation in position in the measurement target region, when the measurement target region is specified incorrectly, or when a plurality of edges are detected. Even if it is included in the measurement target region, a desired edge can be correctly extracted.

Embodiment 2. FIG.
In the first embodiment, an example has been described in which, if a plurality of edges are extracted from the same measurement target region, these edges are displayed on the work image. In contrast, in the present embodiment, a case will be described in which when a plurality of edges are extracted from the same measurement target region, the user is notified that a plurality of edges have been extracted.

  FIG. 12 is a block diagram showing a configuration example of the image measuring instrument 1 according to the second embodiment of the present invention, and shows an example of a functional configuration in the control unit 20. The control unit 20 is different from the control unit 20 of FIG. 3 in that it includes a stability calculation unit 42 and a user notification unit 43, but does not include a geometric feature amount calculation unit 25.

  The stability calculation unit 42 obtains the edge extraction stability for two or more edges extracted from the same measurement target region. For example, even if the edge extraction parameter is changed, the stability is evaluated depending on whether or not the same edge is extracted.

  The edge extraction result display unit 29 selectively displays two or more edges extracted from the same measurement target region based on the stability obtained by the stability calculation unit 42. For example, only edges with high stability are displayed, and edges with low stability are not displayed. By configuring in this way, since the edge with low stability is not displayed, it is possible to prevent the edge extraction parameter from being erroneously determined by the edge with low stability.

  The user notification unit 43 notifies the user that two or more edges have been extracted from the same measurement target region. For example, a message is displayed on the display screen 11 a of the display device 11. The edge extraction result display unit 29 displays two or more edges extracted from the same measurement target region on the work image based on a user operation. That is, when a plurality of edges are extracted from the same measurement target region, first, the user is notified by a message or the like that a plurality of edges are extracted. Then, after the user performs a confirmation operation, the extracted edge is displayed. With this configuration, it is possible to display these edges on the work image after confirming that a plurality of edges have been extracted from the same measurement target region.

DESCRIPTION OF SYMBOLS 1 Image measuring device 10 Measurement unit 11 Display apparatus 11a Display screen 12 Movable stage 14a XY adjustment knob 14b Z adjustment knob 15 Power switch 16 Execution button 100 Case 101 Stage adjustment part 102 Lens barrel part 103 Illumination position adjustment part 110, 120 Camera 130 Coaxial incident illumination unit 140 Ring illumination unit 141 Diffuse illumination device 142 Side illumination device 150 Transmission illumination unit 20 Control unit 21 Imaging control unit 22 Work image storage unit 23 Measurement region designation unit 24 Measurement setting storage unit 25 Geometric features Calculation unit 26 Edge extraction unit 27 Dimension value calculation unit 28 Edge shape designation unit 29 Edge extraction result display unit 30 Edge extraction result selection unit 31 Keyboard 32 Mouse 41 Edge extraction parameter determination unit 42 Stability calculation unit 43 User notification unit 50 Measurement setting Screen 2 workpiece image 3 measurement area 4 edge 5 an edge point

Claims (13)

A camera that shoots a workpiece and generates a workpiece image;
A measurement area designating means for designating a measurement target area for the work image based on a user operation;
Edge extraction means for extracting an edge in the measurement target region;
Edge extraction result display means for displaying two or more edge extraction results for the same measurement target region;
An edge extraction result selection means for selecting any one of the edge extraction results based on a user operation;
An image measuring instrument, comprising: an edge extraction parameter determining means for determining an edge extraction parameter for extracting the selected edge extraction result preferentially over the other edge extraction results.   The image measuring device according to claim 1, wherein the edge extraction result display unit displays the edge extraction result so as to overlap the work image. Measurement setting storage means for holding the edge extraction parameter determined by the edge extraction parameter determination means and the measurement target area specified by the measurement area specifying means as measurement setting data;
In the measurement setting storage means, the edge extraction parameter is held in association with the measurement target region,
3. The edge extracting unit performs edge extraction based on the edge extraction parameter held as the measurement setting data in continuous measurement in which the measurement setting data is designated. Image measuring instrument. In the measurement setting storage means, two or more measurement target areas designated for the same work image by the measurement area designation means, and the edge extraction parameter determination means determined for each of these measurement target areas. The above edge extraction parameters are stored as measurement setting data,
In the continuous measurement, the edge extraction means repeats extracting the edge from the corresponding measurement target area using the edge extraction parameter held as the measurement setting data while changing the measurement target area. The image measuring device according to claim 3.   5. The image measurement according to claim 1, wherein the edge extraction result display means selectively displays any one of two or more edges extracted from the same measurement target region. vessel. Dimension value calculating means for obtaining a dimensional value of the workpiece based on the extracted edge;
A geometric feature amount calculating means for obtaining a geometric feature amount based on the extracted edge;
6. The image measurement according to claim 5, wherein the edge extraction result display means displays the dimension value, the edge point sequence constituting the edge, or the geometric feature amount in association with the edge. vessel. Provided with an edge shape designation means for designating an edge shape based on a user operation,
The image measuring device according to claim 1, wherein the edge extracting unit extracts an edge in the measurement target region based on the specified edge shape.   8. The edge shape designating unit automatically determines a geometric shape to be fitted to an edge point sequence based on region designation information when a user designates the measurement target region. The image measuring instrument described. Stability calculation means for obtaining the stability of edge extraction for two or more of the edges extracted from the same measurement target region,
9. The edge extraction result display means selectively displays two or more edges extracted from the same measurement target region based on the stability. Image measuring instrument.   The edge extraction means extracts a plurality of edges by repeating edge extraction while changing the edge extraction parameter from which only one edge is extracted for the same measurement target region. The image measuring device according to any one of 1 to 9.   The edge extraction parameter determination means determines the edge extraction parameters simultaneously when the edge extraction means repeats edge extraction while changing the edge extraction parameters to extract a plurality of edges. Item 13. The image measuring device according to Item 10.   The edge extracting means groups a large number of edge points extracted from the measurement target region into two or more shape groups according to a geometric figure to be fitted, and specifies an edge for each shape group. The image measuring device according to claim 1. User notification means for notifying the user that two or more edges have been extracted from the same measurement target region,
The said edge extraction result display means displays two or more edges extracted from the same measurement object area | region on a workpiece | work image based on user operation, The one of Claims 1-12 characterized by the above-mentioned. Image measuring instrument.