JP7161430B2 - Image measuring device - Google Patents

Description

The present invention relates to an image measuring device.

The image measuring apparatus captures an image of a work (object to be inspected) to generate a work image, and measures the dimensions of the work based on the work image. According to Patent Document 1, an image measuring apparatus (image dimension measuring apparatus) equipped with a high-magnification camera in addition to a low-magnification camera is proposed.

Japanese Patent No. 5679560

By the way, the position of the workpiece obtained from the image obtained by the high-magnification camera and the position of the workpiece obtained from the image obtained by the low-magnification camera may deviate. This is due to errors in the mounting positions of the high-magnification camera and the low-magnification camera, environmental loads such as temperature and humidity after installation, and mechanical loads such as vibrations and impacts. If such a position measurement error occurs, even a non-defective product may be rejected.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to improve the accuracy of the position of a workpiece measured using a low-magnification imaging device and a high-magnification imaging device.

The present invention, for example,
a mounting table having a light-transmitting plate on which a workpiece is placed on a first surface of the light-transmitting plate;
a transmissive illumination unit provided below the translucent plate for irradiating transmissive illumination light onto the workpiece placed on the translucent plate;
an epi-illumination unit provided above the translucent plate for irradiating epi-illumination light onto the workpiece placed on the translucent plate;
A low-magnification imaging device for imaging the workpiece through a low-magnification optical system to generate a low-magnification image, and a high-magnification optical system having an optical axis coaxial with the optical axis of the low-magnification optical system. and an imaging unit having a high-magnification imaging element that generates a high-magnification image by imaging the
The position of the low-magnification image generated by the low-magnification imaging device and the position of the low-magnification image generated by the high-magnification imaging device provided below the first surface of the light-transmitting plate and above the transmitted illumination unit. a correction member imaged by the imaging unit when creating position correction information for correcting a relationship with the position of the high-magnification image obtained;
A low-magnification image of the correction member is generated by imaging the correction member with the low-magnification imaging device, and a high-magnification image of the correction member is generated by imaging the correction member with the high-magnification imaging device. a processor that creates the position correction information based on a low-magnification image of the correction member and a high-magnification image of the correction member;
a memory that stores the position correction information created by the processor;
The processor uses the position correction information stored in the memory to determine the position of the low-magnification image of the workpiece generated by the low-magnification imaging element and the position of the workpiece generated by the high-magnification imaging element. and the position of the high-magnification image.

According to the present invention, the accuracy of the workpiece position measured using the low-magnification imaging device and the high-magnification imaging device is improved.

Diagram showing the outline of the image measuring device Cross section of measuring unit Diagram explaining the arrangement of the bird's-eye view camera Diagram explaining the controller Flowchart showing main processing Flowchart showing configuration mode Flowchart showing measurement modes Diagram explaining the user interface Diagram explaining the user interface Diagram explaining the user interface Diagram explaining the user interface Diagram explaining the user interface Diagram explaining the user interface Diagram explaining the user interface Diagram explaining the user interface Diagram explaining the user interface Diagram explaining the user interface Diagram explaining the user interface Diagram explaining the user interface Diagram explaining the user interface Diagram explaining the user interface Diagram explaining the user interface Diagram explaining the setting work Flow chart describing a detailed example of S710 Diagram explaining the position correction member Partial sectional view explaining the position correction member Flowchart showing position correction information creation processing Diagram explaining the dust removal process Diagram explaining the dust removal process

Embodiments are described in detail below with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more of the features described in the embodiments may be combined arbitrarily. Identical or similar configurations are given the same reference numerals, and duplicate descriptions are omitted.

<Image measuring device 1>
FIG. 1 is a perspective view showing one configuration example of the image measuring apparatus 1. As shown in FIG. The image measuring apparatus 1 is an image measuring apparatus that captures an image of a workpiece, generates a workpiece image, and measures dimensions of the workpiece within the workpiece image. In FIG. 1, the image measuring apparatus 1 has a measuring unit 10, a control unit 20, a keyboard 31 and a pointing device 32. As shown in FIG. A workpiece is an object whose shape and dimensions are measured by the image measuring apparatus 1 .

The measurement unit 10 has a display device 11 , a movable stage 12 , an XY adjustment knob (not shown), a Z adjustment knob 14 , a power switch 15 and an execution button 16 . The measurement unit 10 irradiates illumination light onto a work placed on a movable stage 12 and receives light transmitted through or reflected from the work to generate a work image. The work is placed on the transparent plate 13 of the movable stage 12 . The measurement unit 10 displays the work image on the display screen 18 of the display device 11 .

The display device 11 is a display device that displays a workpiece image, measurement results, and a setting UI (user interface) on a display screen 18 . The user operates the keyboard 31 and pointing device 32 while looking at the workpiece image displayed on the display device 11 to set characteristic points for pattern search, measurement points for dimension measurement, and the like. The movable stage 12 is a mounting table for mounting a work. The light-transmitting plate 13 is a region made of translucent glass. The movable stage 12 moves in the Z-axis direction parallel to the imaging axis of the camera, and in the X-axis and Y-axis directions perpendicular to the imaging axis.

The XY adjustment knob adjusts the relative position of the movable stage 12 with respect to the camera (the position in the X-axis direction and the position in the Y-axis direction) by moving the movable stage 12 in the X-axis direction or the Y-axis direction. The Z adjustment knob 14 adjusts the relative position (position in the Z-axis direction) of the movable stage 12 with respect to the camera by moving the movable stage 12 in the Z-axis direction. The power switch 15 is an operation unit for switching the main power 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 that controls imaging and screen display by the measurement unit 10, analyzes the workpiece image, and measures the dimensions of the workpiece. The control unit 20 is connected to a keyboard 31 and pointing device 32 and receives user input through the keyboard 31 and pointing device 32 . The keyboard 31 and pointing device 32 form an operating section 30 . The control unit 20 activates the measurement unit 10 when the power switch 15 is switched on. When the execution button 16 is operated, the control unit 20 controls the measurement unit 10 according to setting data prepared in advance, searches for a work within the transparent plate 13, and measures the dimensions of the work.

<Measurement unit 10>
FIG. 2 is a cross-sectional view schematically showing a configuration example of the measurement unit 10. As shown in FIG. Here, a cut plane when the measuring unit 10 cuts along a vertical plane (YZ plane) parallel to the imaging axis is shown. The measurement unit 10 has a display device 11 , a movable stage 12 , a housing 100 , a stage driving section 101 , a lens barrel section 102 , a low magnification camera 110 , a high magnification camera 120 , coaxial epi-illumination 130 and transmissive illumination 150 . . Since the low magnification camera 110 and the high magnification camera 120 are used for dimension measurement, they may be called measurement cameras.

The lens barrel section 102 , the low-magnification camera 110 , the high-magnification camera 120 , the coaxial epi-illumination 130 and the transmissive illumination 150 are arranged inside the housing 100 . The stage drive unit 101Z moves the camera head 103 in the Z-axis direction with respect to the movable stage 12 to adjust the distance between the low-magnification camera 110, the high-magnification camera 120, and the movable stage 12. FIG. Note that the stage driving section 101Z may move the movable stage 12 in the Z-axis direction. The stage drive unit 101Z may move the camera head 103 in order to focus the low-magnification camera 110 and the high-magnification camera 120 on a work or the like. The stage drive unit 101XY moves the movable stage 12 in the X-axis direction and the Y-axis direction.

The low-magnification camera 110 is an imaging device with a low imaging magnification compared to the high-magnification camera 120 . The low-magnification camera 110 has an imaging device 111 , an imaging lens 112 , an aperture plate 113 and a light receiving lens 114 . The imaging lens 112, diaphragm plate 113 and light receiving lens 114 form a low-magnification optical system. The imaging device 111 receives illumination light and generates a workpiece image. The imaging device 111 is arranged with its light receiving surface facing downward. The imaging lens 112 is an optical member that forms an image of illumination light on the imaging device 111 . A diaphragm plate 113 is an optical diaphragm that limits the amount of transmitted illumination light and the depth of field, and is arranged between the imaging lens 112 and the light receiving lens 114 . The light-receiving lens 114 is an optical member that collects the illumination light from the work, and is arranged so as to face the movable stage 12 . Imaging lens 112, aperture plate 113, and light receiving lens 114 are arranged around a central axis extending in the vertical direction.

The high-magnification camera 120 is an imaging device with a higher imaging magnification than the low-magnification camera 110 . The high magnification camera 120 has an imaging device 121 , an imaging lens 122 , an aperture plate 123 , a half mirror 124 and a light receiving lens 114 . The imaging lens 122, diaphragm plate 123, half mirror 124 and light receiving lens 114 form a high magnification optical system. The imaging device 121 receives illumination light and generates a workpiece image. The imaging element 121 is arranged with its light receiving surface directed in the horizontal direction. That is, the light receiving surface and the horizontal direction are orthogonal. The imaging lens 122 is an optical member that forms an image of illumination light on the imaging device 121 . A diaphragm plate 123 is an optical diaphragm that limits the amount of transmitted illumination light, and is arranged between the imaging lens 122 and the half mirror 124 . The light receiving lens 114 is shared by the low-magnification camera 110 and the high-magnification camera 120 . The illumination 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 imaging device 121 via the aperture plate 123 and the imaging lens 122 .

Image sensors such as CCDs (Charge Coupled Devices) and CMOSs (Complementary Metal Oxide Semiconductors) are used as the imaging devices 111 and 121, for example. As the light-receiving lens 114, a telecentric lens is used which has the property of not changing the size of the image of the work even if the distance between the light-receiving lens 114 and the work changes. That is, the low-magnification optical system and the high-magnification optical system each have telecentricity. The workpiece distortion in the workpiece image acquired by the telecentric optical system is very small compared to the workpiece distortion in the workpiece image acquired by the non-telecentric optical system. Therefore, the workpiece can be measured with high accuracy. Note that the low-magnification optical system and the high-magnification optical system do not have to be telecentric.

The coaxial epi-illumination 130 is an illumination device that irradiates the work on the movable stage 12 with illumination light from above. Instead of the coaxial epi-illumination 130, epi-illumination such as ring illumination may be employed. The optical axis of the light emitted from the coaxial epi-illumination 130 coincides with the imaging axis. The coaxial epi-illumination 130 has a light source 131 that is arranged to output illumination light in the horizontal direction, and a half mirror 132 that bends downward the illumination light emitted from the light source 131 . Illumination light from the coaxial epi-illumination 130 is advantageous in obtaining irregularities and patterns on the work surface.

A ring illumination 180 is provided around the light receiving lens 114 . A stage drive unit 181 moves the ring illumination 180 up and down. As a result, the irradiation angle of the illumination to the work is adjusted, and it becomes possible to adjust how the edge is emphasized.

Imaging lenses 112 , 122 , aperture plates 113 , 123 , half mirrors 124 , 132 , and light receiving lens 114 are arranged inside lens barrel 102 .

The transmitted illumination 150 is an illumination device that illuminates the workpiece on the movable stage 12 with illumination light from below. Transmitted illumination 150 is composed of light source 151 , mirror 152 and condenser lens 153 . The light source 151 is arranged to output illumination light in the horizontal direction. Illumination light emitted from the light source 151 is reflected by the mirror 152 and condensed by the condensing lens 153 . The illumination light passes through the movable stage 12 and irradiates the workpiece. A part of the illumination light is blocked by the work, and another part of the illumination light enters the light receiving lens 114 . The illumination light of the transmitted illumination 150 is advantageous when acquiring the outer edge of the workpiece.

As each light source of the coaxial epi-illumination 130 and the transmissive illumination 150, an LED (light-emitting diode) or a halogen lamp is used.

A bird's-eye view camera 17 is an imaging device used to acquire a bird's-eye view image of the movable stage 12 . A bird's-eye view image is an image that includes almost the entire movable stage 12 . The imaging field of view of the overhead camera 17 is wider than the imaging fields of the low-magnification camera 110 and the high-magnification camera 120 . Therefore, the bird's-eye view camera 17 is suitable for acquiring images of a wider range than the low-magnification camera 110 and the high-magnification camera 120 . On the other hand, the telecentricity of the overhead camera 17 is low compared to the telecentricity of the low-magnification camera 110 and the high-magnification camera 120 . Therefore, the overhead camera 17 may be called a non-telecentric camera. Since the shape of the workpiece is distorted in the workpiece image acquired by the bird's-eye camera 17, the bird's-eye camera 17 is not suitable for workpiece measurement compared to the low-magnification camera 110 and the high-magnification camera 120. FIG. The field of view of the optical system is circular, and the object within the field of view forms an image circle on the imaging device. On the other hand, the range that can be imaged by the imaging element is a rectangle. That is, the imaging area is a partial rectangular area within the image circle. Here, a rectangular area on the movable stage 12 corresponding to the imaging area of the imaging element is called an imaging field of view.

<Overhead camera>
As shown in FIG. 2, receiving lens 114 covers a substantial portion of movable stage 12 . Therefore, the bird's-eye view camera 17 is arranged at a position avoiding the light receiving lens 114 . The bird's-eye view camera 17 may be realized by one camera, but may be realized by a plurality of cameras.

FIG. 3A is a diagram illustrating the arrangement of the bird's-eye camera 17 when viewed from the front side of the measurement unit 10. FIG. W indicates a workpiece. In this example, an overhead camera 17L is arranged on the left side of the light receiving lens 114, and an overhead camera 17R is arranged on the right side of the light receiving lens 114. FIG. R1 indicates the visual field range of the low-magnification camera 110. FIG. R2L indicates the visual field range of the overhead camera 17L. R2R indicates the visual field range of the overhead camera 17R. By adopting the two overhead cameras 17R and 17L, most of the movable stage 12 can be imaged at once. Nevertheless, on the movable stage 12, a blind spot range R3 that cannot be covered by the visual field range R2L of the bird's-eye camera 17L and the visual field range R2L of the bird's-eye camera 17L is generated.

FIG. 3B is a diagram illustrating a method of capturing an image of the workpiece W placed near the center of the movable stage 12 with the bird's-eye view camera 17. As shown in FIG. By moving the movable stage 12 so that the optical axis of the bird's-eye view camera 17R and the center of the movable stage 12 match, a bird's-eye view image of the workpiece W placed near the center of the movable stage 12 is obtained. Here, the bird's-eye camera 17R is used, but the bird's-eye camera 17L may be used.

Note that the bird's-eye image acquired by the bird's-eye camera 17L in FIG. 3A, the bird's-eye image acquired by the bird's-eye camera 17R, and the bird's-eye image acquired by the bird's-eye camera 17R in FIG. , a synthetic bird's-eye view image covering the entire movable stage 12 may be created. Although the synthetic bird's-eye view image cannot be created in real time, the synthetic bird's-eye view image can be created when the real-time property is not required.

FIG. 3A illustrates an example in which a blind spot range R3 occurs between the two overhead cameras 17R and 17L. However, depending on the angles of view and installation positions of the two overhead cameras 17R and 17L employed, there may be cases where there is no blind spot range R3 and the entire movable stage 12 can be imaged at once.

<Correction member for correcting camera position>
The mounting position of the low-magnification camera 110 and the mounting position of the high-magnification camera 120 have individual differences for each measurement unit 10 . Moreover, since these have temperature dependent characteristics, they change depending on the environment in which the measurement unit 10 is installed. Although the positions of the features of the work W extracted from the low-magnification image and the positions of the features of the work W extracted from the high-magnification image should be the same, there may be a deviation between them. . Therefore, position correction information is required for correcting the positions of the features of the work W extracted from the low-magnification image and the positions of the features of the work W extracted from the high-magnification image.

As shown in FIG. 2, a correction member 19 is fixed to the rear surface of the transparent plate 13 . The correction member 19 may be provided at any position within the range ZR from the surface of the transparent plate 13 to the transmitted illumination 150 . Note that if the surface of the transparent plate 13 is imaged for height measurement of the work W, the range ZR may be changed to a range from the back surface of the transparent plate 13 to the transmitted illumination 150 . A correction member 19 may be provided inside the transparent plate 13 . For example, the translucent plate 13 may be manufactured by sandwiching the correction member 19 between two glass plates. The correction member 19 is provided with an optical mark that serves as a reference for position correction.

Note that the correction member 19 does not have to be arranged within the range ZR. For example, the correction member 19 can be arranged between the surface of the transparent plate 13 and the light source 151 . The reason is as follows.

It is desirable that the correction member 19 is arranged in a range that does not interfere with normal measurement operations and that is not used for measurement.

When the correction member 19 is arranged on the imaging unit side, particularly when the correction member 109 is arranged within the measurement use range, the correction member 19 interferes with the measurement. The measurement use range refers to the range in which the camera head 103 is moved up and down by the stage driving section 101Z. A case where the correction member 19 is arranged inside the camera head 103 is also conceivable. In particular, arranging the correcting member 19 (pattern) for correction within the lens constituting the optical system of the lens of the light receiving system increases manufacturing difficulty and increases cost.

Conversely, when the correction member 19 is arranged below the surface of the transparent plate 13, the arrangement of the correction member 19 is simplified and the cost is relatively low. Even if the user observes the workpiece W within the measurement use range, it is desirable that the pattern is sufficiently blurred so that the pattern does not interfere with observation. In other words, if the pattern is arranged at a position sufficiently distant from the placement surface of the movable stage 12, the pattern will be sufficiently blurred. As a result, the pattern applied to the correction member 19 is less likely to be affected during normal use (during measurement of the workpiece W).

When the correction member 19 is placed on the surface of the light-transmitting plate 13, the focus may be adjusted to the vicinity of the surface of the light-transmitting plate 13, so the pattern of the correction member 19 is less likely to blur. For example, when trying to focus on a short work W, the correction member 19 formed on the surface of the transparent plate 13 may be in focus.

Further, when the correction member 19 is provided on the surface of the light-transmitting plate 13, the work W is likely to damage the correction member 19 because the work W is mounted thereon. Dust tends to adhere to the correcting member 19, and the accuracy of correction may deteriorate.

Therefore, by arranging the correction member 19 on the back surface of the workpiece W, which is not used for normal measurement, the normally unused area can be effectively used for correction. Furthermore, the compensating member 19 does not interfere with normal measurements. Since the correction member 19 is arranged on the back surface of the work W, the work W and the like do not come into contact with the correction member 19 . Therefore, it is preferable to provide the correction member 19 on the rear surface of the transparent plate 13 .

The image measuring apparatus 1 generates a low-magnification image of the correction member 19 by imaging the correction member 19 with the low-magnification camera 110 . The image measuring device 1 generates a high-magnification image of the correction member 19 by imaging the correction member 19 with the high-magnification camera 120 . The image measuring apparatus 1 creates position correction information based on the difference between the mark position (XY coordinates and rotation angle) in the low-magnification image and the mark position in the high-magnification image.

<Controller>
FIG. 4 is a diagram for explaining the functions of the controller 60 mounted on the control unit 20. As shown in FIG. FIG. 5 shows optional functions required when generating the bird's-eye view image 41 . The controller 60 is composed of a processor (eg, CPU, etc.) and controls the measurement unit 10 . CPU is an abbreviation for central processing unit. Some or all of the functions of controller 60 may be realized by hardware such as ASIC and FPGA. ASIC is an abbreviation for Application Specific Integrated Circuit. FPGA is an abbreviation for Field Programmable Gate Array. The illumination controller 81 is mounted on the control unit 20 or the measurement unit 10 and controls the illumination unit 84 (the coaxial epi-illumination 130 and the transmitted illumination 150) according to control signals from the controller 60. FIG. The imaging control section 82 is mounted on the control unit 20 or the measurement unit 10, and controls the camera unit 85 (the low-magnification camera 110, the high-magnification camera 120, and the overhead cameras 17R and 17L) according to control signals from the controller 60. The storage device 70 has a memory, a hard disk drive, etc., and stores setting data 71, a low-magnification image 43, a bird's-eye view image 41, and the like.

The setting unit 61 creates setting data 71 for measuring the workpiece W according to user input from the keyboard 31 or the like. The setting data 71 includes, for example, setting information related to pattern search (positioning) of the work W, setting information related to measurement locations, non-defective product thresholds, imaging conditions (imaging magnification and illumination conditions), and the like.

The measurement control section 62 turns on any lighting unit through the lighting control section 81 according to the setting data 71, and causes any camera unit to perform imaging through the imaging control section 82. FIG.

Work determination unit 63 extracts an edge from the image acquired by low-magnification camera 110 or high-magnification camera 120 when generating a connected image, and determines the presence or absence of an edge. The work determination unit 63 obtains the extending direction of the edge, and determines the coordinates of the imaging position where the next imaging should be performed. The image connecting unit 64 connects a plurality of low-magnification images 43 including edges of the workpiece W to generate a connected image 42 .

The search unit 66 performs pattern search on the target image acquired by the low-magnification camera 110 based on the setting data 71 to identify the position and orientation of the work W. FIG. For example, the search unit 66 compares the reference image and the target image included in the setting data 71, obtains the amount of positional deviation and the amount of orientational deviation of the target image with respect to the reference image, and determines the amount of positional deviation and the amount of orientation of the target image. A conversion formula for the coordinates of the measurement point is generated from the shift amount of . By inputting the coordinates of each measurement point included in the setting data 71 to this conversion formula, the coordinates of each measurement point with respect to the workpiece W to be measured are determined. The search unit 66 also converts the coordinates of each measurement point into machine coordinates of the imaging position corresponding to each measurement point. The search unit 66 obtains the shortest route (imaging order) for imaging all the machine coordinates of the respective imaging positions of the plurality of measurement points. The measurement control unit 62 sets the machine coordinates of each measurement point in the stage driving unit 101XY according to the imaging order, and drives the movable stage 12 . Furthermore, the imaging control unit 82 performs imaging by applying imaging conditions (imaging magnification and illumination conditions) based on the setting data 71 for each measurement point to the lighting unit and the camera unit. For example, if the imaging magnification is low, imaging control section 82 causes low-magnification camera 110 to perform imaging of the measurement location. If the imaging magnification is high, the imaging control unit 82 causes the high-magnification camera 120 to perform imaging of the measurement point. Thus, a workpiece image is generated for each measurement point.

The measurement unit 67 performs various measurements on the work W from the work image according to the setting data 71 . The workpiece image may be a connected image 42 generated by connecting a plurality of low-magnification images or high-magnification images for each measurement location, or a single low-magnification image or high-magnification image for each measurement location. may be The measuring section 67 has a plurality of measuring tools. Several measurement tools include a line-to-line distance measurement tool that measures the distance between a line and another line, a point-to-line distance measurement root that measures the distance between a point and a line, a line and A squareness measurement tool or the like that measures squareness to other lines may also be included. The measurement unit 67 recognizes these points and lines as edges in the image and performs measurement based on the edges. For example, the measurement unit 67 performs dimension measurement using one or more edges included in the workpiece image. The measurement unit 67 may perform dimension measurement using a predetermined edge included in the first low-magnification image and a predetermined edge included in the second low-magnification image. The measurement unit 67 may perform dimension measurement using a predetermined edge included in the first high-magnification image and a predetermined edge included in the second high-magnification image. The measurement unit 67 may perform dimension measurement using a predetermined edge included in the low-magnification image and a predetermined edge included in the high-magnification image. The measurement unit 67 may compare the measurement result with a non-defective product threshold to determine (inspect) whether or not the work W is a non-defective product. The creation unit 68 creates or updates the position correction information 44 based on the low-magnification image of the correction member and the high-magnification image of the correction member. The position correction unit 69 corrects the relationship between the position of the feature extracted from the low-magnification image and the position of the feature extracted from the high-magnification image based on the position correction information 44 acquired in advance. That is, the measurement unit 67 performs various measurements using the edge positions corrected by the position correction unit 69 .

The display control unit 83 displays a UI for creating the setting data 71 on the display device 11 according to instructions from the controller 60, displays various images, and displays measurement results (inspection results).

<Flowchart>
FIG. 5 is a flow chart showing main processing executed by the controller 60 when the power switch 15 is turned on.

In S500, the controller 60 (creation unit 68 and position correction unit 69) creates position correction information. The storage device 70 stores default position correction information 44 for correcting these positional relationships in the assembly process of the measuring unit 10 (at the time of shipment from the factory). When the power switch 15 is turned on and the controller 60 is activated, the controller 60 (creation unit 68) executes creation processing (update processing) to create the position correction information 44, which is stored in the storage device 70. The position correction information 44 is updated. The position corrector 69 corrects at least one of the coordinates for the low-magnification image and the coordinates for the high-magnification image based on the position correction information 44 . As a result, the feature position of the work W extracted from the low-magnification image and the feature position of the work W extracted from the high-magnification image are the same.

In S<b>501 , the controller 60 determines whether or not the setting mode has been selected by the user through the operation unit 30 . If the setting mode is not selected, the controller 60 skips S502 and proceeds to S503. On the other hand, if the setting mode has been selected, the controller 60 proceeds to S502.

In S502, the controller 60 (setting unit 61) executes the setting mode. Details of the setting mode will be described later with reference to FIG.

In S<b>503 , the controller 60 determines whether or not the user has selected the measurement mode through the operation unit 30 . If the measurement mode has not been selected, the controller 60 returns to S501. On the other hand, if the measurement mode has been selected, the controller 60 proceeds to S504.

In S504, the controller 60 determines whether the execution button 16 has been operated by the user. When the execution button 16 is operated by the user, the controller 60 proceeds to S505.

In S505, the controller 60 (measurement control section 62) executes the continuous measurement mode. Details of the continuous measurement mode will be described later with reference to FIG.

●Setting Mode FIG. 6 is a flow chart showing the setting mode.

In S<b>601 , the controller 60 uses the bird's-eye camera 17 to generate a bird's-eye view image. This overhead image may be used in the setting mode or may be used in the measurement mode. In particular, the bird's-eye view image will be useful when roughly positioning the workpiece W with respect to the movable stage 12 . Note that S601 is omitted when the bird's-eye view image is not used.

FIG. 8 shows the user interface 160a displaying the overhead image IM01. The overhead image IM01 here is generated using the overhead camera 17R. The controller 60 moves the movable stage 12 so that the center of the movable stage 12 coincides with the optical axis of the bird's-eye camera 17R, and causes the bird's-eye camera 17R to perform imaging, thereby generating the bird's-eye image IM01 and displaying it on the display device 11. do. When the bird's-eye image IM01 acquired in S601 is used in the setting mode or the measurement mode, the bird's-eye image IM01 is held in the storage device .

The controller 60 (image connecting unit 64) generates a connected image of the workpiece W in S602. It is convenient for the user to have an image showing almost the entire work W in order to set the measurement points for each measurement tool on the work W. FIG. However, creating a connected image while scanning the entire movable stage 12 using the low-magnification camera 110 or the high-magnification camera 120 requires an enormous amount of time. Normally, the area of the workpiece W in plan view is smaller than the area of the movable stage 12 . Therefore, the controller 60 (work determination unit 63) detects the edge of the work W using the low-magnification camera 110, and moves the movable stage 12 so as to follow the edge (outer edge) of the work W, thereby generating a plurality of low-magnification images. to generate Furthermore, the controller 60 (image connecting unit 64) generates a connected image representing substantially the entire work W by connecting a plurality of low-magnification images. Each low-magnification image is captured with both epi-illumination and trans-illumination, which will be described later. That is, a low-magnification image is acquired with the epi-illumination turned on and the transmitted illumination turned off, and another low-magnification image is acquired with the epi-illumination turned off and the transmitted illumination turned on. A concatenated image is generated by concatenating a plurality of low-magnification images acquired using epi-illumination, and this concatenated image has texture information of the surface of the workpiece W. FIG. On the other hand, another connected image is generated by connecting a plurality of low-magnification images acquired using transmitted illumination, and the edge of the contour portion of the work W is clear in this another connected image.

FIG. 9 shows the user interface 160b displayed on the display device 11 during generation of the connected image. In particular, FIG. 9 shows an example of joining low-magnification images taken with epi-illumination. The work determination unit 63 generates a low-magnification image IM02 while extracting edges, and the work determination unit 63 or the image linking unit 64 associates the generated low-magnification image IM02 with the imaging position and maps it on the user interface 160b. ,indicate. In this example, 20 low-magnification images IM02 are generated.

In S603, the controller 60 (image connecting unit 64) displays the connected image of the workpiece W on the display device 11. FIG.

FIG. 10 shows a user interface 160c for displaying the completed concatenated image IM03. In this example, the image connecting unit 64 generates a connected image IM03 by connecting 21 low-magnification images IM02 based on the imaging positions.

In S604, the controller 60 (setting unit 61) accepts the setting of the measurement point. In S605, the controller 60 (setting unit 61) acquires an image of the measurement point at the specified magnification. In S606, the controller 60 (setting unit 61) accepts the setting of the measurement tool.

A connected image generated so as to include the entire workpiece W is an image used by the user to make measurement settings.

FIG. 11 shows a user interface 160d displayed on the display device 11 for accepting setting of measurement points. A user interface 160d generated by the setting unit 61 has a display area for displaying the connected image IM03. The user operates the pointer 161 to select the measurement tool from the tool selection section 163a, select the imaging magnification from the magnification selection section 163b, and select the lighting type, brightness, etc. (illumination conditions) from the illumination selection section 163c. If the lighting control unit 81 has a function of automatically adjusting the amount of light, the selection of brightness may be omitted. The user designates the measurement point 162a by selecting an edge to be extracted in the connected image. The setting unit 61 controls the imaging control unit 82 and the lighting control unit 81 so as to perform imaging of the measurement point 162a with the magnification and lighting conditions selected by the user. Any one of epi-illumination, transmissive illumination, and ring illumination can be selected as the illumination condition. The ring light can be moved up and down. When the ring lighting is selected, the user can set the vertical position of the ring lighting. Note that the lighting conditions may be automatically set based on the sharpness (contrast) of the edges selected by the user. Further, the focus position (in-focus position) may be automatically adjusted based on the sharpness (contrast) of the edge while automatically changing the focus at the selected imaging magnification. The setting unit 61 displays an image acquired with the selected magnification, illumination condition, and automatically adjusted focal position for the measurement point 162a superimposed on the combined image IM03. The user visually confirms whether the edges are properly extracted. In this example, since low magnification and transmitted illumination are selected, the image obtained for the measurement point 162a is a transmitted illumination image in which the edge of the outer edge of the workpiece W is emphasized. The user operates the pointer 161 to set the edge 164a that serves as the reference for the distance measured by the selected measuring tool. Since the length measurement tool is selected in this example, the length is measured from some reference point (eg, another edge, the center of a circle, etc.) to edge 164a. Although not shown in FIG. 11, the setting unit 61 also accepts setting of measurement locations that serve as reference points. The setting unit 61 assigns identification information to each measurement point, associates the type of the selected measurement tool (measurement content), the position of the measurement point, and the like, and creates setting data.

FIG. 12 shows a user interface 160d displayed on the display device 11 for accepting setting of measurement points. In this example, the user operates the pointer 161 to select the measurement point 162a. The user selects the squareness measurement tool from the tool selection section 163a, selects high magnification from the magnification selection section 163b, and selects epi-illumination from the illumination selection section 163c. A squareness tool is a tool that measures squareness about two edges. The setting unit 61 changes the measurement location 162a corresponding to the low magnification to the measurement location 162b corresponding to the high magnification, causes the coaxial epi-illumination 130 to perform illumination through the illumination control unit 81, and controls the movable stage 12 through the imaging control unit 82. It is moved to the measurement point 162b, and the high-magnification camera 120 is caused to take an image. The setting unit 61 displays a high-magnification image at the measurement point 162b.

FIG. 13 shows a user interface 160e for enlarging the measurement point 162b. When the setting unit 61 detects that the measurement point 162b is clicked by the pointer 161, it displays the user interface 160e. The user operates the pointer 161 on the high-magnification image IM04 corresponding to the measurement point 162b to set the edge 164b to be measured. Although not shown in FIG. 13, the setting unit 61 sets the edge 164a (FIG. 11) to be measured according to the user's instruction. Thus, in this example the squareness is measured for edge 164a shown in FIG. 12 and edge 164b shown in FIG. The setting unit 61 assigns identification information to each measurement point, and associates the selected type of measurement tool (measurement content), the position of the measurement point, and the like. Note that the measurement point may be composed of a plurality of edge extraction points, or may be composed of one edge extraction point. A measurement point composed of one edge extraction point includes, for example, a measurement point for measuring the diameter of a hole, a measurement point for measuring the roundness of a hole, and the like.

In S607, the controller 60 (setting unit 61) accepts the pattern search setting.

FIG. 14 shows a user interface 160f for accepting pattern search settings. The workpiece determination unit 63 generates a transmitted illumination image together with an epi-illumination image when creating a connected image IM03, and connects a plurality of transmitted illumination images to generate a connected image IM05. The user interface 160f has a display area for the connected image IM05. The setting unit 61 receives settings of a search area 166 in which pattern search is performed and a registration area 167 of the reference image. Search area 166 may be referred to as an imaging range. The setting unit 61 stores the coordinates of the search area 166 and the coordinates of the registration area 167 specified by the user in the connected image IM05 in the setting data 71 . Setting unit 61 extracts an image included in registration area 167 as a reference image. The reference image contains features related to the shape of the workpiece W used in pattern search. The setting unit 61 obtains position information indicating the relative positional relationship of the coordinates of each measurement point with respect to the coordinates of the reference image, and stores it in the RAM of the storage device 70 or the like as measurement point information. The measurement point information is used to determine the measurement point in the workpiece image acquired for each workpiece in the measurement mode. The setting unit 61 converts the coordinates of the search area 166 in the connected image IM05 into machine coordinates, and stores them in the RAM of the storage device 70 or the like as part of the reference imaging position information.

In S<b>608 , the controller 60 (setting unit 61 ) saves the reference image, reference imaging position information, measurement point information, imaging setting information, and the like in the setting data 71 , and stores the setting data 71 in the storage device 70 .

(Explanation of the relationship between the measurement points and each shooting condition using the work of the use case)
FIG. 23A is a plan view of the workpiece W for explaining an example of setting data stored in the storage device. FIG. 23B is a side view of the work W corresponding to the setting data. FIG. 23C shows the magnification, illumination conditions, and focal position at each measurement point in the setting data. The measurement point 2301a is a non-penetrating hole. Since the edge of the measurement point 2301a cannot be extracted with transmitted illumination, epi-illumination is set. If the measurement point 2301a is small, edges cannot be extracted with sufficient resolution at a low magnification. Therefore, the magnification is set to a high magnification. The in-focus position is automatically adjusted and set to Z1. Note that Z1 may indicate the height (distance) with respect to the mounting surface of the movable stage 12 .

Since the measurement point 2301b is a linear edge forming the contour of the workpiece W, transmitted illumination is selected. In addition, for such a contour, edges can be extracted with sufficient accuracy even at a low magnification, so the magnification is set to a low magnification. The in-focus position for the measurement point 2301b is automatically set to Z1 as with the measurement point 2301a.

Edges can be extracted at a low magnification for the measurement point 2301c. However, since the edge is connected to the R surface, it is necessary to select a ring illumination that emits slit light and set the height of the ring illumination to an appropriate height.

As described above, the user appropriately sets the magnification, illumination conditions, and focus position according to the characteristics of each measurement location. Further, each measurement point is associated with information indicating a relative positional relationship with respect to the reference image registered in the pattern search setting. Therefore, when the pattern search succeeds, machine coordinates (relative positional information between the stage and the camera unit) for photographing each measurement point are automatically determined. Note that FIG. 23A also exemplifies a preset pattern search area 2300 .

●Measurement Mode FIG. 7 is a flow chart showing the continuous measurement mode.

In S701, the controller 60 (measurement control unit 62) displays an image on the display device 11 to assist the user in placing the workpiece W. FIG.

FIGS. 15A and 16 show a user interface 160g including guidance information for assisting or guiding the placement of the workpiece W by the user. The user interface 160g displays the bird's-eye images IM01a and IM01b acquired in the setting mode in an overlapping manner together with the bird's-eye images IM01a and IM01b, which are live images. In this example, work W1 indicates a work image acquired in the setting mode, and work W2 is the current live image. That is, when the user moves the work W, the work W2 displayed on the user interface 160g is also moved. Alignment frame 171 is a frame corresponding to search area 166 . The alignment frame 171 is fixed with respect to the overhead images IM01a and IM01b acquired in the setting mode. The user positions the work W1 on the movable stage 12 so that the characteristic portion of the work W2 fits within the alignment frame 171 or the work W2 overlaps the work W1. The measurement control unit 62 may assist the positioning of the workpiece W2 by displaying the overhead images IM01a and IM01b obtained in the setting mode translucently. Thus, the image of the alignment frame 171 and the work W1 is an example of guidance information for assisting or guiding the placement of the work W by the user.

In S702, the controller 60 (measurement control unit 62) determines whether an instruction to start measurement has been given. For example, when the execution button 16 is pressed, the measurement control section 62 determines that the start of measurement has been instructed. If the measurement start has not been instructed, the controller 60 returns to S701. If the measurement start is instructed, the controller 60 proceeds to S703.

In S703, the controller 60 (search unit 66) moves the movable stage 12 to the imaging position for pattern search based on the setting data 71 (reference imaging position information). Generally, low-magnification images are generated in a predetermined sequence from the upper left corner of the movable stage 12 or the center of the movable stage 12, and a low-magnification image that matches the reference image is searched for. Therefore, it takes a long time for pattern search. On the other hand, in the present invention, since the imaging position (machine coordinates) of the search area 166 is stored in advance in the setting data 71, the search unit 66 can immediately move the movable stage 12 to the imaging position of the search area 166. can be done. In other words, imaging processing for searching for the search area 166 and repeated movement of the movable stage 12 are not required. If the user who performed the setting and the user who performed the measurement are the same, the user remembers the predetermined position where the non-defective workpiece was placed on the movable stage 12 in the setting mode. Therefore, the user can position each workpiece to be measured at a predetermined position based on his/her own memory. On the other hand, the user who performed the setting and the user who performed the measurement usually do not match. In this case, it would be difficult for the user performing the measurement to position each workpiece in place. Therefore, the measurement control section 62 may display the alignment frame 171 corresponding to the search area 166 on the display device 11 . This makes it easier for the user to reproduce the placement of the work W in the setting mode. That is, there is a high probability that the positioning feature extracted from the reference image exists at the imaging position (machine coordinates) of the search area 166 determined in the setting mode. This will allow the pattern search to be completed in a short time.

Also, the bird's-eye view image acquired in the setting mode and the current bird's-eye view image may be translucently displayed at the same time. As a result, the user can be guided to place the work W so that the pattern search is successful. When the two translucent images are superimposed, the position and orientation of the work W in the setting mode and the current position and orientation of the work W are the same, so that the characteristic portion of the work is automatically included in the search area.

In this embodiment, the guidance information for assisting or guiding the placement of the workpiece W includes the translucent display of the alignment frame 171 and the bird's-eye view image described above.

(Supplementary explanation about going searching first)
FIG. 15B is a diagram showing the relative position of the search area 1502 set by the user with respect to the entire stage movable range 1500. FIG. 1503 indicates the field of view of the low-magnification camera 110 . 1504 indicates the field of view of the high-magnification camera 120 . A search area 1502 is an area formed by connecting nine low-magnification images. The numbers assigned to the nine low-magnification images indicate the order of photographing. If the search area 1502 is set large, the pattern search becomes robust against positional displacement of the work W, but the number of images to be captured increases. If the search area 1502 is set small, the pattern search will not succeed unless the position and orientation of the work W are substantially the same as those set in the setting mode. However, the number of shot images is reduced.

Once the pattern search is successful, the preset measurement points can be identified. Therefore, each measurement point is photographed in turn with preset magnification, lighting conditions, and focal position, and the measurement can be completed in a short time.

In addition, although an example in which one search area 1502 is set is shown in the above embodiment, two or more search areas 1502 may be set. As a result, for example, the pattern search succeeds even when the work W is rotated 180 degrees with respect to the reference posture.

In S704, the controller 60 (search unit 66) acquires a target image for pattern search. The search unit 66 acquires the target image using the low-magnification camera 110 according to the setting data 71 .

FIG. 17 shows a user interface 160h displayed during execution of pattern search. A user interface 160h generated by the search unit 66 or the measurement control unit 62 displays a low-magnification image IM06 acquired as a target image using the low-magnification camera 110. FIG. Thumbnail image IM06' is a thumbnail image of the reference image acquired in the setting mode. By comparing these images, the user can confirm that the pattern search has been performed correctly.

In S705, the controller 60 (search unit 66) uses the reference image included in the setting data 71 to execute pattern search on the target image. The search unit 66 obtains the amount of positional deviation in the X direction, the amount of positional deviation in the Y direction, and the orientation (rotational angle in the XY plane) of the workpiece W2 to be measured from the reference image. S720 and S721 may be inserted between S705 and S706.

At S720, the controller 60 (search unit 66) determines whether the pattern search was successful based on the result of the pattern search. If the pattern search is successful, the controller 60 proceeds to S706. If the pattern search fails, the controller 60 proceeds to S721.

In S721, the controller 60 displays on the display device 11 a notification (screen) prompting the user to place the workpiece W in the correct position and orientation. After that, the controller 60 returns to S704. Alternatively, the controller 60 may transition to an automatic search mode in which the workpiece W is searched automatically. The controller 60 repeats photographing while regularly moving the movable stage 12 until the workpiece W enters the field of view. When the work W is captured within the field of view, the controller 60 repeats photographing while moving the movable stage 12 along the contour of the work W, and generates a connected image of the work W by connecting a plurality of acquired images. . The controller 60 executes pattern search on the connected image of the workpiece W to identify the measurement points.

In S706, the controller 60 (measurement control unit 62) determines the imaging position of each measurement point based on the measurement point information of the setting data 71 and the result of the pattern search. Since the position of a non-defective work in the setting mode and the position of each work in the measurement mode often do not match, the imaging position of each measurement point needs to be adjusted for each work. The measurement control unit 62 positionally corrects the coordinates of each measurement point included in the measurement point information based on the result of the pattern search (the position and orientation of each workpiece), and further converts the position-corrected coordinates into machine coordinates (imaging position).

In S707, the controller 60 (measurement control unit 62) determines the measurement order of each measurement point based on the imaging position (machine coordinates) of each measurement point. As described above, the measurement control unit 62 determines the measurement order of each measurement point so as to take the shortest route.

In S708, the controller 60 (measurement control unit 62) acquires an image by controlling the movable stage 12 and the camera unit based on the determined measurement order and imaging setting information. If the imaging setting information designates high magnification, the high magnification camera 120 images the work W. FIG. If the imaging setting information designates low magnification, the low magnification camera 110 images the workpiece W. FIG. In addition, the measurement control unit 62 turns on any one of the coaxial epi-illumination 130, the transmitted illumination 150, and the ring illumination 180 according to the set illumination conditions.

That is, the controller 60 controls the movable stage 12 so that the machine coordinates of each measurement point specified based on the result of the pattern search can be photographed. The high-magnification camera 120 and the low-magnification camera 110 have a bifurcated optical system using a half mirror, and can acquire a high-magnification image and a low-magnification image at the same time. Therefore, only by moving the movable stage 12, an image with a magnification associated with each measurement point can be acquired at high speed. An image measuring device using a revolver or a zoom lens may be employed to obtain a plurality of images with different magnifications. In this case, it takes time to change the magnification with the revolver or the zoom lens, but since the bifurcation optical system is used, it is possible to acquire a high-magnification image and a low-magnification image at the same time, and the time required for photography will be shortened.

18 and 19 show the user interface 160i displayed during the imaging process. In FIG. 18, the measurement control unit 62 displays on the user interface 160i a display area for displaying the image IM07 of the measurement point acquired at each measurement point and a display area for displaying an enlarged image IM07′ of the image IM07. good. In this example, image IM07 is a low magnification image. In FIG. 19, the measurement control unit 62 displays on the user interface 160i a display area for displaying the image IM08 of the measurement point acquired at each measurement point and a display area for displaying an enlarged image IM08′ of the image IM08. good. In this example image IM08 is a high magnification image. By referring to the user interface 160i, the user can confirm that the image is accurately acquired at each measurement point.

The enlarged images IM07' and IM08' may be thumbnail images of the measurement points acquired in the setting mode. By comparing the images IM07 and IM08 with the thumbnail images, the user can easily confirm that the images are acquired at the correct measurement points.

In S<b>709 , the controller 60 (measurement unit 67 ) performs dimension measurement for each measurement point based on the images IM07 and IM08 and the measurement point information, and stores the measurement results in the storage device 70 . For example, the measurement unit 67 uses a measurement tool according to the measurement point information to extract an edge from each predetermined point, and measures the distance, diameter, squareness, circularity, etc., based on the edge. The measurement point information may include a threshold value such as a tolerance that serves as a reference for pass/fail judgment (OK/NG judgment).

In S710, the controller 60 (measurement unit 67) displays the measurement result on the display device 11 together with the connected image (or bird's-eye view image) acquired in the setting mode.

Figures 20-22 show a user interface 160j for displaying measurement results. In FIG. 20, the user interface 160j has an image display area 168 and a result display area 169. FIG. The image display area 168 is an area for displaying the work images IM09 to IM11 acquired in S708. Work images IM09 and IM10 are low-magnification images. Work image IM11 is a high-magnification image. As described above, in the present invention, images are acquired only at the positions required for measurement on the movable stage 12, so that the measurement time is shortened. The measurement unit 67 may display numeric information 170 indicating the measurement results and content information 172 indicating the details of the measurement together with the low-magnification image and the high-magnification image. Content information 172 may include, for example, information indicating the start and end points of the measured distance. Also, the content information 172 may include a bidirectional arrow or the like indicating distance. In addition, the content information 172 may include a unit indicating the measurement result (eg, millimeters, etc.). The result display area 169 displays the identification information of the measurement points (example: 1, 2, ...), the measurement details (example: line-line distance), the measurement result (example: 114.368 mm), and the pass/fail judgment result (example: : OK/NG), etc.

As FIG. 20 shows, the controller 60 can measure the dimension between the edge extracted from the high magnification image and the edge extracted from the low magnification image. This is because there is a calibration that corrects the position of the high-magnification camera 120 and the position of the low-magnification camera 110 .

A correction member provided with an optical mark that serves as a reference for position correction may be provided on the rear surface of the light-transmitting plate 13 provided on the movable stage 12 . The controller 60 images the optical mark with both the high-magnification camera 120 and the low-magnification camera 110 and corrects the positions of the high-magnification camera 120 and the low-magnification camera 110 . Note that the method of position correction is not limited to this. For example, the high-magnification camera 120 and the low-magnification camera 110 image an adjustment jig such as a calibration chart placed on the movable stage 12 . The controller 60 may correct the positions of the high-magnification camera 120 and the low-magnification camera 110 based on the positional deviation amount of the position correction marks shown in the two images.

In the present invention, images are acquired only at positions necessary for photographing the measurement point. Therefore, the positions of the images acquired during measurement are discrete positions with respect to the connected image of the work W acquired in the setting mode. Images are acquired in the measurement mode only for a portion of the concatenated images acquired in the setup mode. Assuming that only the image acquired in the measurement mode is displayed on the display device 11 without acquiring the connected image acquired in the setting mode, the display screen of the measurement result is as shown in FIG. In other words, a plurality of images are arranged discretely, and it is difficult for the user to understand which position of the entire work W the measurement results are displayed. Therefore, in the present embodiment, as shown in FIG. 21, in the image display area 168, the work images IM09 to IM11 obtained in the measurement mode are superimposed on the connected image IM03 obtained in the setting mode. be done.

In the setting mode, the connected image 42 is stored in the storage device 70 together with the setting data 71 . The connected image 42 is displayed on the user interface in the setting mode, and is displayed on the display device 11 when accepting various measurement settings. Furthermore, the concatenated image 42 is read from the storage device 70 also in the measurement mode, and the measurement result is displayed superimposed on the concatenated image. This will make it easier for the user to visually confirm at which position in the entire work W the measurement result was acquired. Here, the measurement result includes a pass/fail judgment result, a measured value, a symbol indicating the position where the measurement was performed, and the like. When displaying the symbol, the measured value may be displayed in a display area different from the display area where the connected image 42 is displayed.

The positional information of each measurement point is determined based on relative coordinate positional information with respect to the reference image for pattern search. Therefore, if the pattern search succeeds, the display position of the measurement result can also be determined.

In addition, in the present invention, in the measurement mode, the low-magnification image or the high-magnification image obtained at each measurement point is superimposed on the combined image and displayed. As a result, in the connected image, only the measurement location is replaced with or superimposed on the image actually acquired in the measurement mode and displayed. Therefore, if the desired measurement result is not obtained, the user can check the actual image acquired in the measurement mode. As a result, the user will be able to visually understand why the desired measurement result was not obtained.

FIG. 24 is a detailed flowchart of S710. In S709, the controller 60 executes measurement based on the measurement point information and the acquired image, and then proceeds to S2401. In S2401, the controller 60 reads out the connected image 42, which is stored in the storage device 70 and is acquired in the preset mode. At S2402, the controller 60 determines the display position of the measurement result based on the pattern search result obtained at S705. In S2403, the controller 60 displays the captured image obtained in the measurement mode and the measurement result superimposed on the combined image 42 previously obtained in the setting mode (eg, FIG. 21).

Note that the image display area 168 may display the connected image IM03 acquired in the setting mode and not display the workpiece images IM09 to IM11 acquired in the measurement mode.

As shown in FIG. 22, the measurement unit 67 may enlarge and display the work image IM11 of the measurement location specified by the user. When a specific measurement point is clicked by pointer 161 , measurement unit 67 displays work image IM<b>11 corresponding to the clicked measurement point in image display area 168 . This will help the user to verify that the correct edges are being measured.

<Details of position correction>
When measuring the workpiece, the surface of the workpiece positioned higher than the mark-applied surface in the Z direction is measured. In other words, since the mark is blurred when measuring the workpiece, the mark hardly affects the measurement of the workpiece. From this point of view, the dot-shaped mark is superior to the cross-shaped mark.

Conventionally, it was necessary to set a chart for correction on a mounting table or the like, but such a chart is not required in this embodiment. It would be very convenient for the user to perform the position correction by using the stage glass as it is.

In this embodiment, a transmissive (translucent) film with a mark attached is attached to the stage glass, but this is only an example. A mask may be applied to the stage glass by chrome mask, glass mask, etching, or the like.

●Position Correcting Member and Marks FIG. 25A shows a plurality of marks M provided on the correcting member 19 in a grid pattern. The pitch of the marks M is, for example, 1 mm. If a circular mark is adopted as the mark M, its diameter may be 30um. FIG. 25B shows a cross-shaped mark M provided on the correction member 19. FIG. It should be noted that dust or the like tends to adhere to the transparent plate 13 . Therefore, in order to distinguish between the dust and the mark M, it is possible to adopt a design for the shape of the mark M or a design for image processing (dust removal processing).

FIG. 26A is a diagram showing the structure of the correction member 19. FIG. The correction member 19 may be a laser-markable film. The correcting member 19 has an adhesive layer for attaching the correcting member 19 to the rear surface of the transparent plate 13 . A mat material layer is provided under the adhesive layer. The matting material layer may have silica grains having a diameter greater than or equal to 2um and less than or equal to 7um. A gelatin layer is provided under the mat material layer. Another layer of matting material is provided under the gelatin layer. This mat material layer may also have silica grains with a diameter of 2 um or more and 7 um or less. A photosensitive layer is provided under one mat material layer. A desired mark M is created by irradiating the photosensitive layer with a laser beam (laser marking).

FIG. 26B is a diagram showing another structure of the correction member 19. FIG. In comparison with FIG. 26(A), in FIG. 26(B), the photosensitive layer is provided between the adhesive layer and the upper mat material layer. In FIG. 26B, when autofocusing is performed, the mark M and the lowermost mat material layer are brought into focus. The mat material layer generally contains silica grains, and when viewed in an image, the silica grains have a contrast. On the other hand, in FIG. 26A, since the adhesive layer covers the silica grains and integrates them materially, only the mark M is difficult to focus on. Therefore, the structure shown in FIG. 26(A) would be preferable.

● Flowchart FIG. 27 is a flow chart showing the processing for creating position correction information. This creation process corresponds to S500. Here, a low-magnification image and a high-magnification image are acquired at a plurality of measurement positions (measurement locations) on the transparent plate 13, the mark M is extracted, and the positions of both the marks M in the low-magnification image and the high-magnification image are obtained. Position correction information is created based on the statistical value of the deviation amount. Here, as an example, a plurality of marks M provided in a grid pattern are provided on the entire surface of the light-transmitting plate 13 or at least on all measurement points.

In S2501, the controller 60 (creation unit 68) controls the stage driving unit 101XY to move the movable stage 12 to a predetermined start position.

In S<b>2502 , the controller 60 (creation unit 68 ) determines whether or not there is an obstacle (eg, workpiece) within the field of view of the low-magnification camera 110 . That is, the creation unit 68 has an obstacle determination unit. The creation unit 68 turns on the transmitted illumination 150, causes the low-magnification camera 110 to acquire a low-magnification image, binarizes the low-magnification image (divides it into black pixels and white pixels), and calculates the area of a group of black pixels. (a so-called blob). Furthermore, the creation unit 68 compares each blob with a threshold and determines whether there is a blob that is equal to or greater than the threshold. If there are blobs equal to or greater than the threshold, there is an obstacle within the field of view, so the controller 60 proceeds to S2512. In S2512, the controller 60 (creation unit 68) controls the stage drive unit 101XY to move the movable stage 12 according to a predetermined obstacle avoidance rule. The obstacle avoidance rule may be, for example, moving the movable stage 12 in the X direction by a predetermined distance and moving the movable stage 12 in the Y direction by a predetermined distance. Alternatively, the controller 60 (creation unit 68) may output a warning. For example, the creation unit 68 may display a warning message on the display device 11 to warn the user not to place a workpiece or the like on the transparent plate 13 . Thus, the creating section 68 has an obstacle avoidance section or a warning output section. After that, the controller 60 returns to S2502. If there are no blobs equal to or greater than the threshold, there is no obstacle within the field of view, so the controller 60 proceeds to S2503.

In S2503, the controller 60 (creation unit 68) uses the transmitted illumination 150 to acquire a low-magnification image and a high-magnification image. In this manner, the creation unit 68 may have an image acquisition unit. The image acquisition unit turns on the transmission illumination 150 and turns off the coaxial epi-illumination 130 via the illumination control unit 81 . Furthermore, the image acquisition section causes the low-magnification camera 110 and the high-magnification camera 120 to perform imaging respectively via the imaging control section 82 . Note that the imaging control unit 82 controls the stage driving unit 101Z so that the mark M is in focus.

In S2504, the controller 60 (creation unit 68) binarizes the low-magnification image to obtain blobs, and binarizes the high-magnification image to obtain blobs. In this way, the creation unit may have a binarization unit and a blob operation unit.

In S2505, the controller 60 (creation unit 68) excludes images other than the mark M based on the blob for each of the low-magnification image and the high-magnification image. Thus, the generator 68 may have an image exclusion section or a candidate exclusion section. If dust or the like adheres to the light-transmitting plate 13 or if a small work W is placed thereon, these images interfere with the detection of the mark M. Therefore, the creating unit 68 uses the upper limit value and the lower limit value of the blob determined based on the correct mark M to distinguish between the mark M and dust or the like. For example, if the blob is equal to or less than the upper limit value and equal to or more than the lower limit value, the creation unit 68 determines the blob as a mark M candidate. If the blob exceeds the upper limit value or is less than the lower limit value, the creation unit 68 determines the blob as dust D and excludes it from the mark M candidates.

FIG. 28 shows a low-magnification image IM15 and a high-magnification image IM16 in which dust D is captured. The dust D blob is much larger compared to the mark M. Dust D is distinguished from mark M because the blob of dust D exceeds the upper limit.

In addition, the creating unit 68 may distinguish between the mark M and dust or the like by using the upper limit value and the lower limit value of the blob that are predefined based on the mark M for the length of the blob in the X direction. Furthermore, the creation unit 68 may distinguish between the marks M and dust or the like using upper and lower limits of the blobs defined in advance based on the marks M for the length of the blobs in the Y direction. In FIG. 28, the length of the dust D in the X direction exceeds the upper limit. Also, the length of the dust D in the Y direction exceeds the upper limit. Therefore, dust D is excluded.

Since the shape and area of the mark M are known in this way, the above upper limit value and lower limit value are defined in advance and stored in the storage device 70 . As a result, only relatively suitable candidates remain among the plurality of extracted blobs (candidates for mark M).

Furthermore, the creation unit 68 obtains the distance to the adjacent candidate in the X direction and the distance to the adjacent candidate in the Y direction for each candidate, and compares these distances with predetermined upper and lower limit values. Candidates can be narrowed down. Thus, the creating unit 68 may have a distance determining unit. If dust having the same shape and area as the mark M adheres, it is difficult to distinguish between the mark M and the dust only by the shape and area. Therefore, the creation unit 68 may select candidates using the distance between adjacent blobs (candidates).

FIG. 29 shows a low-magnification image IM17 and a high-magnification image IM18 in which dust D is captured. In this example, since the size of the dust D is the same as that of the mark M, it is impossible to distinguish between the mark M and the dust only by the shape and area. Moreover, the intervals in the X direction for the plurality of marks M are constant, and the intervals in the Y direction are also constant. Therefore, the creation unit 68 obtains the distance between each candidate and the adjacent candidate, and determines that the distance is equal to or less than a predetermined upper limit value and is equal to or more than the lower limit value, thereby excluding dust D. good.

In S2506, the controller 60 (creation unit 68) determines pairs of mark M candidates acquired from the high-magnification image and mark M candidates acquired from the low-magnification image (pair list creation). The creating unit 68 obtains the position (XY coordinates) of the mark M candidate extracted from the high-magnification image, and obtains the position (XY coordinates) of the mark M candidate extracted from the low-magnification image. The creation unit 68 identifies the mark M candidate extracted from the low-magnification image that is closest to the position (XY coordinates) of the mark M candidate extracted from the high-magnification image, and determines the mark M extracted from the high-magnification image. and a candidate for the mark M extracted from the low-magnification image are paired and registered in a pair list. As described above, the creation unit 68 has a pair determination unit and a pair list creation unit. A pair list is held in the storage device 70 .

In S2507, the controller 60 (creation unit 68) determines the position of the mark M candidate extracted from the high-magnification image and the position of the mark M candidate extracted from the low-magnification image for each pair registered in the pair list. A deviation amount (XY coordinates and angle) is obtained. In this manner, the creating unit 68 may have a shift amount calculating unit.

In S2508, the controller 60 (creation unit 68) compares the amount of deviation of each pair with a threshold value, and excludes (deletes) pairs whose amount of deviation is equal to or greater than the threshold value from the pair list. Thus, the creating unit 68 may have a pair exclusion unit.

In S2509, the controller 60 (creation unit 68) obtains a statistic value (eg, average value) of the amount of deviation of the pairs remaining in the pair list. Thus, the creating unit 68 may have a statistical value calculating unit.

In S2510, the controller 60 (creation unit 68) determines whether statistical values of the amount of deviation have been obtained for the N measurement positions. The N measurement positions may, for example, be scattered so as to cover the entire translucent plate 13 . Also, N may be one. The larger N is, the more accurate the position correction information is. The smaller N becomes, the shorter the processing time of the creation process becomes. If deviation statistics have not been determined for the N measurement positions, the controller 60 proceeds to S2513. In S2513, the controller 60 controls the stage driving section 101XY to move the movable stage 12 to the next measurement position. After that, the controller 60 returns to S2502. That is, S2503 to S2510 are executed for each measurement position. Once the statistical values of the amount of deviation are obtained for the N measurement positions, the controller 60 proceeds to S2511.

In S2510, the controller 60 (creation unit 68) creates position correction information based on the statistical values of the deviation amounts obtained at the N measurement positions. The creation unit 68 determines at least one of the positions extracted from the low-magnification image and the positions extracted from the high-magnification image so that the positions extracted from the low-magnification image and the positions extracted from the high-magnification image match. Create position correction information for correction. The creating unit 68 may update the position correction information by overwriting the position correction information stored in the storage device 70 with the created position correction information. Also, the position correction information obtained at the time of shipment from the factory may be held without being erased.

In the method according to the comparative example, the position correction is performed at a timing different from the timing of measuring the workpiece and the timing of executing the settings necessary for performing the workpiece measurement. In other words, a dedicated member for position correction must be placed on the mounting table to adjust the positional information of the low-magnification imaging element and the high-magnification imaging element. On the other hand, by using the correction member 19 as in this embodiment, it becomes possible to adjust the positional information together with the timing of measuring the workpiece or the timing of setting. In other words, a separate adjustment work becomes unnecessary, and the user's burden will be reduced. Further, position correction is performed using a correction member 19 provided in the image measuring apparatus 1 . Therefore, there is no need to bother to place a dedicated member for position correction on the mounting table.

<Summary>
The movable stage 12 is an example of a mounting table on which a work is mounted. The camera unit 85 has a low-magnification optical system for imaging a workpiece at a low magnification and generating a low-magnification image, and an optical axis coaxial with the optical axis of the low-magnification optical system. 1 is an example of an imaging unit having a high-magnification optical system for imaging at a magnification and generating a high-magnification image. The stage driving unit 101XY is an example of a driving unit that changes the imaging position of the imaging unit by driving at least one of the mounting table and the imaging unit so that the mounting table and the imaging unit move relative to each other in the XY directions. be. The controller 60 controls the driving unit and the imaging unit, generates a plurality of low-magnification images or high-magnification images of different parts of the workpiece, and connects the generated low-magnification images or high-magnification images by connecting them. Acts as a processor to generate images. The storage device 70 functions as a memory that stores connected images. As described with reference to FIG. 6 and the like, in the setting mode, the processor captures a reference image for pattern search, which is at least a part of the connected image, or a position specified by the user in the connected image using the imaging unit. A reference image for pattern search generated by doing so may be stored in the memory. The processor may cause the memory to store measurement point information indicating a plurality of measurement points designated by the user in the connected image. For example, the measurement point information may include information indicating the relative position of the measurement point with respect to the reference image (reference imaging position) in the combined image. Note that the imaging position information is determined in the measurement mode from the relative positions of the measurement points included in the measurement point information and the result of the pattern search. That is, the processor may cause the memory to store imaging position information indicating the imaging position of the imaging unit for imaging each of the plurality of measurement locations. For example, the imaging position may be represented by the machine coordinate system of movable stage 12 . In the setting mode, the processor may cause the memory to store imaging setting information indicating whether to image each imaging position at a low magnification or a high magnification. As described with reference to FIG. 7 and the like, in the measurement mode, the processor controls the imaging unit, acquires the target image for pattern search, and uses the reference image for pattern search stored in the memory to obtain the pattern. A pattern search is executed for the search target image. The processor identifies a plurality of imaging positions for imaging each of the plurality of measurement locations based on the measurement location information associated with each of the plurality of measurement locations and the results of the pattern search stored in the memory. That is, relative position information for each measurement point with respect to the reference imaging position is converted into absolute imaging position information. Further, the processor sequentially sets the imaging position of the imaging unit to each of the plurality of imaging positions by causing the driving unit to drive at least one of the mounting table and the imaging unit, and performs imaging at each of the plurality of imaging positions. A low-magnification image or a high-magnification image is generated by causing the imaging unit to perform imaging at a magnification according to the setting information. Both a low-magnification image and a high-magnification image may be generated depending on the setting of the measurement point. The processor measures the dimension of the measurement point corresponding to each imaging position based on the low-magnification image or the high-magnification image acquired for each of the plurality of imaging positions. In this way, since imaging is performed at the magnification specified for each measurement point, the number of times of imaging in the measurement mode is reduced, and image measurement can be performed efficiently. In addition, since it is no longer essential to perform imaging at the measurement point and to perform imaging over the entire workpiece, the number of times of imaging can be reduced. Dimensional measurement is performed each time a workpiece is placed on the movable stage 12 . Therefore, reducing the number of imaging times for each work improves the efficiency of dimension measurement.

Transmitted illumination 150 is provided below a mounting table that is at least partially translucent. The transmitted illumination 150 functions as a transmitted illumination unit that irradiates the workpiece placed on the mounting table with transmitted illumination light. Transmitted illumination light is light directed upward from below the mounting table. The camera unit 85 receives the transmitted illumination light output from the transmitted illumination 150 that is not blocked by the workpiece. Therefore, the outline (outer edge) of the work is emphasized in the work image. Transmitted illumination light is therefore advantageous for dimensional measurement of the outer shape of the workpiece. The coaxial epi-illumination 130 and the ring illumination are provided above the mounting table and function as an epi-illumination section that irradiates the work mounted on the mounting table with epi-illumination light. For example, in S606 of the setting mode, the processor may cause the memory to store illumination conditions indicating whether to use the transmitted illumination unit or the epi-illumination unit for each of the plurality of measurement locations. The lighting conditions may be included in the imaging setting information. In the measurement mode, the processor illuminates the illumination section according to the illumination conditions stored in the memory, out of the transmission illumination section and the epi-illumination section, for each of the plurality of measurement locations. Since the illumination conditions are set for each measurement point in this manner, different illumination light can be applied for each measurement point. This will improve the measurement accuracy of dimensions.

A low-magnification camera 110 is an example of a low-magnification imaging device that images a workpiece via a low-magnification optical system. The high-magnification camera 120 is an example of a high-magnification imaging device that images a workpiece through a high-magnification optical system. As shown in FIG. 2, the low-magnification optical system and the high-magnification optical system may form a branching optical system having the same optical axis. The memory may store position correction information for correcting the relationship between the position of the low-magnification image generated by the low-magnification imaging element and the position of the high-magnification image generated by the high-magnification imaging element. The processor corrects the relationship between the position of the low-magnification image and the position of the high-magnification image based on the position correction information. Since there is an assembly error in the low-magnification camera 110 and the high-magnification camera 120, the position of the workpiece extracted from the low-magnification image may not match the position of the workpiece extracted from the high-magnification image. In addition, an error occurs in the positional relationship between them depending on the temperature of the environment in which the measurement unit 10 is installed. Therefore, by performing position correction, the accuracy of dimension measurement is improved. In particular, position correction may be important in the case of measuring the distance from features (edges) extracted from the low magnification image to features (edges) extracted from the high magnification image.

The display device 11 is an example of a display device that displays an image of a workpiece. In the measurement mode, the processor may cause the display device to display a low-magnification image and a high-magnification image of the images including the part of the work in a distinguishable manner. As shown in FIGS. 20 and 21, an image of a part of the work is acquired in the measurement mode. Also, the user may wish to know that the image was acquired correctly at the set magnification for each measurement point. Therefore, it is useful to display a low-magnification image and a high-magnification image in a distinguishable manner. For example, the controller 60 may cause the borders of the low-magnification images and the high-magnification images to be different. For example, the border color of the low-magnification image and the border color of the high-magnification image may be different. The border thickness of the low-magnification image and the border thickness of the high-magnification image may be different. The border of the low-magnification image may be a solid line, and the border of the high-magnification image may be a dashed line. It would be sufficient if such visually distinct display objects were employed.

As described with reference to FIG. 22, in the measurement mode, the processor displays the entire image including the entire workpiece on the display device, accepts the designation of a portion of the entire image from the user, A low-magnification image or a high-magnification image corresponding to the location may be displayed on the display device. As shown in FIG. 21 and the like, the area of one high-magnification image is considerably small with respect to the entire area of the workpiece. Therefore, it becomes difficult for the user to visually recognize the features appearing in the high-magnification image from the high-magnification image mapped on the entire image of the workpiece. Therefore, when the user designates a high-magnification image in the entire image, the processor may enlarge and display the high-magnification image on the display device. This makes it easier for the user to visually recognize the features appearing in the high-magnification image. Here, magnified display of a high-magnification image has been described, but similarly, the processor may perform magnified display of a low-magnification image.

As described in connection with S604 and the like, in the setting mode, the processor designates the measurement location of the workpiece imaged through the low-magnification optical system and the measurement location of the workpiece imaged through the high-magnification optical system. The imaging setting information may be created by receiving the designation.

As described in relation to S602 and S603, in the setting mode, the processor generates a plurality of low-magnification images using the low-magnification optical system so as to cover the entire workpiece, and generates a plurality of low-magnification images. A concatenated image (whole image) showing the entire work may be generated by concatenating. As described in relation to S604 and S605, the processor may generate a high-magnification image using the high-magnification optical system for the portion specified by the user in the combined image. In this way, high-magnification images are acquired only at locations specified by the user, so the number of times of capturing high-magnification images is reduced even in the setting mode. That is, the user's waiting time associated with imaging is reduced.

As described in relation to S607, in the setting mode, the processor acquires the position information indicating the imaging position of the low-magnification image and the imaging position of the high-magnification image based on the result of the pattern search, the reference imaging position information, and the measurement point information. The imaging position information may be created so as to include the position information indicating the position. The position of the work on the movable stage 12 differs for each work. This is because the workpiece is placed manually by the user. Therefore, the imaging position of each measurement point is dynamically determined according to the position and posture of each workpiece. The position and orientation of each workpiece are specified by pattern search using the reference image. In other words, the imaging position corresponding to the measurement point information is corrected according to the positional deviation amount and posture deviation amount of each workpiece with respect to the reference image (reference imaging position), and the imaging position of each measurement point is dynamically determined. . This eliminates the need for a jig or the like for positioning the work, so that the user can freely place the work.

As described with reference to FIG. 6, in the setting mode, the processor turns off the transmissive illumination section and turns on the epi-illumination section when acquiring the target image for pattern search. A setting as to whether or not to generate an image may be accepted. In the measurement mode, when generation of an epi-illumination image is set, the processor generates a pattern search target image by irradiating the workpiece with transmitted illumination light from the transmitted illumination unit, and By turning off the light and turning on the epi-illumination unit, an epi-illumination image of the workpiece is generated. If generation of an epi-illumination image is not set, the processor irradiates the workpiece with transmitted illumination light from the transmitted illumination unit in the measurement mode to generate a pattern search target image. Transmitted illumination light is advantageous for pattern search in the case where an image including the outer shape of a workpiece is used as a reference image. In the case where the reference image is an image containing features inside the outline of the workpiece, epi-illumination light is advantageous for pattern search. Therefore, the user may select the illumination light according to the characteristics of the pattern search.

The processor may generate a thumbnail image of the workpiece using the low-magnification image or the high-magnification image in the setting mode. For example, different measurement settings may be stored with multiple settings data. In this case, if the user can visually recognize a thumbnail image that symbolizes each measurement setting (setting data), the user will be able to visually distinguish each measurement setting (setting data). The controller 60 may create a thumbnail image (an image generated by reducing the low-magnification image or the high-magnification image used for setting the measurement location) for each setting data, and save it in the setting data. When the user selects setting data, the controller 60 may display a thumbnail image of each setting data on the display device 11 . As shown in FIGS. 17-19, thumbnail images may be displayed in the measurement mode.

The processor, in the measurement mode, may measure the workpiece using edges extracted from the low-magnification image and edges extracted from the high-magnification image. In general, the distance between the first edge extracted from the low-magnification image and the second edge extracted from the low-magnification image is measured, or the first edge extracted from the high-magnification image and the edge extracted from the high-magnification image are measured. A distance to the second edge is measured. However, by making it possible to measure workpieces using the edges extracted from the low-magnification image and the edges extracted from the high-magnification image, it will be possible to meet the diverse needs of users.

As FIG. 21 shows, the processor (measuring unit 67) may display the measurement result in the measurement mode together with the connected image acquired in the setting mode. In this way, by using the connected image acquired in the setting mode, it is possible to display the measurement result together with the connected image while shortening the processing time in the measurement mode.

As shown in FIG. 21, in the measurement mode, the processor (measuring unit 67) replaces an image region including the measurement point in the connected image with a low-magnification image or a high-magnification image corresponding to the measurement point, and In addition, the measurement result of the measurement point may be displayed on the display device. An image of the measurement point is always acquired in the measurement mode. Therefore, the image of the measurement point may be synthesized or superimposed on the connected image and displayed. That is, the display device superimposes the measurement result on the concatenated image acquired in the setting mode, or displays the measurement result by synthesizing the concatenated image acquired in the setting mode. A composite image may be displayed. The image of the measurement point is suitable for the user to visually check the measurement error of the measurement point, the manufacturing error of the measurement point, and the like. Therefore, it would be desirable for the images of the measurement locations to be images obtained individually from each workpiece.

The processor (measuring unit 67) replaces an image region including the measurement point in the connected image with a low-magnification image or a high-magnification image corresponding to the measurement point, and displays the measurement result of the measurement point along with the connection image on the display device. You may

The processor (controller 60) may store the connected image, the reference image, the reference imaging position information, the measurement point information, and the imaging setting information in the setting file (setting data 71). In addition, the processor may store thumbnail images in the settings file that are representative of the measurements specified by the settings file. The bird's-eye view cameras 17R and 17L function as bird's-eye cameras that acquire a bird's-eye view image of the mounting table. The processor may store the bird's-eye view image as a thumbnail image in the setting file. In general, the bird's-eye view image shows the entire workpiece. Therefore, the user will be able to easily select a desired setting file from among a plurality of setting files by referring to the thumbnail image of the bird's-eye view image.

The UI shown in FIGS. 20 and 21 may be improved. For example, the display device (display device 11) may display a user interface including a first display area and a second display area in the measurement mode. The first display area may display a connected image showing the entire work. The second display area may display an image or a thumbnail image acquired at the measurement location. This allows the user to check the measurement points while checking the entire workpiece.

As shown in FIG. 21, the display device may display a connected image showing the entire workpiece, information indicating measurement points, and measurement results for each measurement point.

As is clear from FIG. 20, the number of low-magnification images or high-magnification images acquired for each measurement location in the measurement mode is less than the number of Therefore, the processing time required for imaging in the measurement mode is shortened.

As described in relation to S607, in the setting mode, the processor may cause the memory to store reference imaging position information indicating the imaging position of the reference image. As described in connection with S703, in the measurement mode, the processor drives at least one of the mounting table and the imaging unit with the driving unit according to the reference imaging position information stored in the memory, thereby moving the imaging unit. is moved to the imaging position of the reference image. This shortens the pattern search processing time. In particular, the closer the position of the workpiece used when acquiring the reference image is to the position of the workpiece to be measured, the shorter the pattern search time will be.

In the measurement mode, when the pattern search is successful, the processor (controller 60) may identify a plurality of imaging positions for imaging each measurement location. In the measurement mode, if the pattern search fails, the processor may display information prompting adjustment of the position of the workpiece on the mounting table on the display device. This will make it easier for the user to reproduce the work placement position determined in the setting mode in the measurement mode as well.

When the measurement mode is started, the processor (controller 60) first drives at least one of the mounting table and the imaging section by the driving section according to the reference imaging position information stored in the memory, thereby adjusting the imaging section. The imaging position may be moved to the imaging position of the reference image. This would allow the pattern search to begin immediately.

In the measurement mode, when the pattern search is completed, the processor (controller 60) performs imaging of each measurement point based on the measurement point information associated with each measurement point stored in the memory and the result of the pattern search. A plurality of imaging positions may be identified.

In the setting mode, the processor (controller 60) may cause the memory to store the positional information of the imaging range (eg, search area 166) of the reference image specified by the user. As shown in FIGS. 15 and 16, in the measurement mode, the processor guides placement of the workpiece together with the live image acquired by the imaging unit based on the position information of the imaging range of the reference image stored in the memory. You may display the guidance information for doing on a display apparatus. This will make it easier for the user to properly adjust the position of the workpiece.

As shown in FIG. 16, the guidance information may include a frame (eg, alignment frame 171) in which the characteristic portion of the workpiece included in the reference image is stored. The position of the workpiece on the mounting table may be adjusted by the user so that the characteristic portion of the workpiece fits within the frame displayed on the display device.

In the setting mode, the processor (controller 60) accepts designation of a registration area 167, which is an area for acquiring a reference image, and designation of a search area 166, which is an area for pattern searching of the reference image, with respect to the connected image. good too. The frame may coincide with the outer edge of the search area.

As shown in FIG. 16, the live image may be a bird's-eye view image generated by a bird's-eye camera. This will make it easier for the user to understand the position of the workpiece with respect to the movable stage 12 . The bird's-eye camera may have a first camera (eg, bird's-eye camera 17R) and a second camera (eg, bird's-eye camera 17L) having different imaging ranges. The live image and the overhead image may be images acquired by both or one of the first camera and the second camera.

As shown in FIG. 16, the guidance information may include a bird's-eye view image (eg, image of work W1) generated by a bird's-eye camera in the setting mode. For example, as shown in FIG. 16, the display device may display the bird's-eye image generated by the bird's-eye camera translucently in the setting mode so that the bird's-eye image is superimposed on the live image. This will allow the user to adjust the position of the workpiece W2 to be measured so that the image of the workpiece W2 to be measured overlaps the image of the workpiece W1.

As described with reference to FIG. 2, the correction member 19 is provided below the first surface (surface) of the translucent plate 13 and above the transmitted illumination section, and is generated by a low-magnification imaging device. It functions as a correction member imaged by the imaging unit when creating position correction information for correcting the relationship between the position of the low-magnification image and the position of the high-magnification image generated by the high-magnification imaging device. The controller 60 (creation unit 68) generates a low-magnification image of the correction member by imaging the correction member with a low-magnification imaging device, and generates a high-magnification image of the correction member by imaging the correction member with a high-magnification imaging device. It functions as a processor that generates images and creates position correction information based on the low magnification image of the correction member and the high magnification image of the correction member. The storage device 70 functions as a memory that stores the position correction information 44 created by the processor. The controller 60 (position correction unit 69) uses the position correction information 44 stored in the memory to adjust the position of the low-magnification image of the workpiece generated by the low-magnification imaging device and the workpiece generated by the high-magnification imaging device. is corrected for the position of the high-magnification image. This improves the accuracy of the position of the workpiece measured using the low-magnification imaging device and the high-magnification imaging device.

The correction member 19 may be provided anywhere as long as it is below the second surface (rear surface) of the transparent plate 13 and above the transmissive illumination section. As shown in FIG. 26A and the like, the correction member 19 may be fixed to the second surface of the transparent plate 13 .

The storage device 70 may store default position correction information acquired when the vision measurement device is manufactured at the factory. The controller 60 may update the default position correction information with the created position correction information. As a result, the position will be corrected by the position correction information suitable for the environment in which the image measuring apparatus is installed.

The controller 60 turns on the transmission illumination section, turns off the epi-illumination section, and generates a low-magnification image of the correction member 19 by imaging the correction member with the low-magnification imaging device, and captures the correction member with the high-magnification imaging device. The imaging may generate a high magnification image of the correction member. Thus, the transmitted illumination light makes the mark M easier to detect.

The controller 60 may perform the creation of the position correction information 44 when the vision measurement device is powered and activated. Thus, position correction information may be incorporated into the activation sequence. The controller 60 may execute the creation process according to user instructions input from the operation unit 30 .

As shown in FIG. 26A and the like, the correction member 19 may be a translucent resin member. The area of the correction member 19 and the area of the translucent plate 13 may be substantially equal. As shown in FIG. 25A and the like, the correction member 19 may be provided with a repeating pattern (eg, marks M).

The controller 60 and the imaging control section 82 may function as an adjustment section (autofocus section) that adjusts the focus of the imaging section. The correction member is arranged at a position such that when the imaging unit is focused on the workpiece, the imaging unit is not focused on the repeated pattern. As a result, the mark M is less likely to be captured when the workpiece W is imaged. That is, the mark M becomes less likely to affect the measurement of the workpiece W.

As shown in FIG. 25A, the repeating pattern may be dots arranged in a grid. As shown in FIG. 25B, the repeating pattern may be cross marks.

The controller 60 may use at least one of the low-magnification image and the high-magnification image of the workpiece W to measure the workpiece. For example, the measurement unit 67 may perform dimension measurement using a predetermined edge included in the low-magnification image and a predetermined edge included in the high-magnification image. The positions of these edges are corrected by the position correction section 69 using the position correction information 44 .

The invention is not limited to the above embodiments, and various modifications and changes are possible within the scope of the invention.

Claims (10)

a mounting table having a light-transmitting plate on which a workpiece is placed on a first surface of the light-transmitting plate; a transmitted illumination unit that irradiates a workpiece with transmitted illumination light; an epi-illumination unit that is provided above the transparent plate and illuminates the workpiece placed on the transparent plate with incident illumination light; and a low-magnification optical system. A low-magnification imaging element for imaging the workpiece through a low-magnification image sensor and a high-magnification optical system having an optical axis coaxial with the optical axis of the low-magnification optical system to image the workpiece at a high magnification. an imaging unit having a high-magnification imaging element that generates a magnified image; and the low-magnification image generated by the low-magnification imaging element provided between the first surface of the light-transmitting plate and the transmitted illumination unit. and the position of the high-magnification image generated by the high-magnification image pickup device. A low-magnification image of the correction member is generated by imaging the correction member, a high-magnification image of the correction member is generated by imaging the correction member with the high-magnification imaging device, and the correction member is a processor that creates the position correction information based on the low-magnification image of and the high-magnification image of the correction member; and a memory that stores the position correction information created by the processor, Using the position correction information stored in the memory, the position of the low-magnification image of the work generated by the low-magnification imaging device and the high-magnification image of the work generated by the high-magnification imaging device An image measuring device that corrects the relationship with the position of an image. 2. The image measuring apparatus according to claim 1, wherein said correction member is provided below the second surface of said transparent plate and above said transmission illumination section. 3. The image measuring apparatus according to claim 2, wherein said correction member is fixed to said second surface of said transparent plate. The memory stores default position correction information obtained when the vision measurement apparatus is manufactured in a factory, and the processor updates the default position correction information with the created position correction information. The image measuring device according to any one of claims 1 to 3. The processor turns on the transmitted illumination unit, turns off the epi-illumination unit, and generates a low-magnification image of the correction member by imaging the correction member with the low-magnification imaging device, and the high-magnification imaging. 5. The vision measuring apparatus according to any one of claims 1 to 4, wherein a high-magnification image of the correction member is generated by imaging the correction member with an element. 6. The image measuring apparatus according to any one of claims 1 to 5, wherein the processor creates the position correction information when power is supplied to the image measuring apparatus and activated. The image measuring apparatus according to any one of claims 1 to 6, wherein the correction member is a translucent resin member, and the area of the correction member and the area of the transparent plate are substantially equal. The correcting member is provided with a repeating pattern, and further comprising an adjusting unit for adjusting the focus of the imaging unit, wherein when the imaging unit is focused on the workpiece, the imaging unit is focused on the repeating pattern. 8. The image measuring apparatus according to claim 7, wherein said correction member is arranged at a position that does not match. 9. The image measuring apparatus according to claim 1, wherein said processor uses at least one of said low-magnification image and said high-magnification image of said workpiece to measure said workpiece. The image measuring apparatus according to any one of claims 1 to 9, wherein the correcting member is a transparent film having a repeating pattern, and is attached to the second surface of the transparent plate.

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