JP2020153686A - Image measuring device - Google Patents

Abstract

To improve accuracy in a position of a workpiece measured using a low-magnification imaging element and a high-magnification imaging element.SOLUTION: A correction member is captured by an imaging unit when position correction information is created which is used to correct a relationship between a position of a low-magnification image generated by a low-magnification imaging element and a high-magnification image generated by a high-magnification imaging element. A processor generates a low-magnification image about the correction member by capturing the correction member by the low-magnification imaging element, generates a high-magnification image about the correction member by capturing the correction member by the high-magnification imaging element, and creates position correction information on the basis of the low-magnification image about the correction member and the high-magnification image about the correction member. The processor corrects the relationship between the position of the low-magnification image about the workpiece generated by the low-magnification imaging element and the position of the high-magnification imaging element of the workpiece generated by the high-magnification imaging element using the position correction information.SELECTED DRAWING: Figure 1

Description

The present invention relates to an image measuring device.

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

Japanese Patent No. 5679560

By the way, the position of the work obtained from the image acquired by the high-magnification camera may deviate from the position of the work obtained from the image acquired by the low-magnification camera. This is an error in the mounting positions of the high-magnification camera and the low-magnification camera, and changes over time due to environmental loads such as temperature and humidity after equipment installation and mechanical loads such as vibration and shock. If such a position measurement error occurs, even a good product may be judged as rejected.

Therefore, an object of the present invention is to improve the accuracy of the position of the work measured by using the low-magnification image sensor and the high-magnification image sensor.

The present invention is, for example,
A mounting table having a translucent plate on which a work is placed on the first surface of the translucent plate,
A transmissive illumination unit provided below the translucent plate and irradiating a work placed on the transmissive plate with transmitted illumination light.
An epi-illumination unit provided above the translucent plate and irradiating a work placed on the translucent plate with epi-illumination light.
The work via a low-magnification image pickup element that images the work 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. An image pickup unit having a high-magnification image pickup element that captures an image and generates a high-magnification image,
The position of the low-magnification image provided below the first surface of the light-transmitting plate and above the transmitted illumination unit and generated by the low-magnification image sensor, and generated by the high-magnification image sensor. A correction member imaged by the image sensor when creating position correction information for correcting the relationship with the position of the high-magnification image.
A low-magnification image of the correction member is generated by imaging the correction member with the low-magnification image sensor, and a high-magnification image of the correction member is generated by imaging the correction member with the high-magnification image sensor. A processor that creates the position correction information based on the low-magnification image of the correction member and the high-magnification image of the correction member.
It has a memory for storing position correction information created by the processor, and has
Using the position correction information stored in the memory, the processor uses the position of the low-magnification image for the work generated by the low-magnification image sensor and the work generated by the high-magnification image sensor. Provided is an image measuring device for correcting the relationship with the position of the high-magnification image.

According to the present invention, the accuracy of the position of the work measured by using the low-magnification image sensor and the high-magnification image sensor is improved.

The figure which shows the outline of the image measuring apparatus Sectional view of the measuring unit Diagram explaining the arrangement of the bird's-eye view camera Diagram illustrating the controller Flowchart showing main processing Flowchart showing the setting mode Flowchart showing measurement mode Diagram illustrating the user interface Diagram illustrating the user interface Diagram illustrating the user interface Diagram illustrating the user interface Diagram illustrating the user interface Diagram illustrating the user interface Diagram illustrating the user interface Diagram illustrating the user interface Diagram illustrating the user interface Diagram illustrating the user interface Diagram illustrating the user interface Diagram illustrating the user interface Diagram illustrating the user interface Diagram illustrating the user interface Diagram illustrating the user interface Diagram explaining the setting work A flowchart illustrating a detailed example of S710. The figure explaining the position correction member Partial sectional view explaining the position correction member Flowchart showing the process of creating position correction information Diagram explaining the garbage exclusion process Diagram explaining the garbage exclusion process

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. 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 plurality of features described in the embodiments may be arbitrarily combined. In addition, the same or similar configurations are given the same reference number, and duplicate explanations are omitted.

<Image measuring device 1>
FIG. 1 is a perspective view showing a configuration example of the image measuring device 1. The image measuring device 1 is an image measuring device that captures a work, generates a work image, and measures the dimensions of the work in the work image. In FIG. 1, the image measuring device 1 includes a measuring unit 10, a control unit 20, a keyboard 31, and a pointing device 32. The work is a measurement object whose shape and dimensions are measured by the image measuring device 1.

The measurement unit 10 includes 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 measuring unit 10 irradiates the work placed on the movable stage 12 with illumination light, receives the transmitted light of the work or the reflected light from the work, and generates a work image. The work is placed on the translucent 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 work image, a measurement result, and a setting UI (user interface) on the display screen 18. By operating the keyboard 31 and the pointing device 32 while looking at the work image displayed on the display device 11, the user sets a feature location for pattern search, a measurement location for dimension measurement, and the like. The movable stage 12 is a mounting table for mounting the work. The translucent plate 13 is a region made of translucent glass. The movable stage 12 moves in the Z-axis direction parallel to the image pickup axis of the camera and in the X-axis direction and the Y-axis direction perpendicular to the image pickup axis.

The XY adjustment knob adjusts the relative position (position in the X-axis direction and position in the Y-axis direction) of the movable stage 12 with respect to the camera 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 the dimension measurement.

The control unit 20 is a controller that controls imaging and screen display by the measurement unit 10 and analyzes the work image to measure the dimensions of the work. The control unit 20 is connected to the keyboard 31 and the pointing device 32, and receives user input through the keyboard 31 and the pointing device 32. The keyboard 31 and the pointing device 32 form an operation unit 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 the setting data prepared in advance, searches for a work in the light transmitting 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. Here, the cut surface when the measurement unit 10 is cut by a vertical plane (YZ plane) parallel to the imaging axis is shown. The measurement unit 10 includes a display device 11, a movable stage 12, a housing 100, a stage drive unit 101, a lens barrel unit 102, a low-magnification camera 110, a high-magnification camera 120, a coaxial epi-illumination 130, and a transmission illumination 150. .. Since the low-magnification camera 110 and the high-magnification camera 120 are used for dimensional measurement, they may be called measurement cameras.

The lens barrel portion 102, the low-magnification camera 110, the high-magnification camera 120, the coaxial epi-illumination 130, and the transmission illumination 150 are arranged in the housing 100. The stage drive unit 101Z moves the camera head 103 with respect to the movable stage 12 in the Z-axis direction, and adjusts the distance between the low-magnification camera 110 and the high-magnification camera 120 and the movable stage 12. The stage drive unit 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 the 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 having a lower imaging magnification than the high-magnification camera 120. The low-magnification camera 110 includes an image sensor 111, an imaging lens 112, an aperture plate 113, and a light receiving lens 114. The imaging lens 112, the diaphragm plate 113, and the light receiving lens 114 form a low-magnification optical system. The image sensor 111 receives the illumination light and generates a work image. The image sensor 111 is arranged with the light receiving surface facing downward. The imaging lens 112 is an optical member that forms an image of illumination light on the image sensor 111. The diaphragm 113 is an optical diaphragm that limits the amount of transmitted light and the depth of field of illumination light, 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 illumination light from the work, and is arranged so as to face the movable stage 12. The imaging lens 112, the diaphragm plate 113, and the light receiving lens 114 are arranged about a central axis extending in the vertical direction.

The high-magnification camera 120 is an imaging device having a higher imaging magnification than the low-magnification camera 110. The high-magnification camera 120 includes an image sensor 121, an imaging lens 122, an aperture plate 123, a half mirror 124, and a light receiving lens 114. The imaging lens 122, the diaphragm plate 123, the half mirror 124, and the light receiving lens 114 form a high-magnification optical system. The image sensor 121 receives the illumination light and generates a work image. The image sensor 121 is arranged so that the light receiving surface faces the horizontal direction. That is, the light receiving surface and the horizontal direction are orthogonal to each other. The imaging lens 122 is an optical member that forms an image of illumination light on the image sensor 121. The diaphragm plate 123 is an optical diaphragm that limits the amount of transmitted light of 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 horizontally bent by the half mirror 124 and is imaged on the image sensor 121 via the diaphragm plate 123 and the imaging lens 122.

As the image pickup devices 111 and 121, for example, image sensors such as CCD (Charge Coupled Devices) and CMOS (Complementary Metal Oxide Semiconductor) are used. As the light receiving lens 114, a telecentric lens having a 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 is used. That is, the low-magnification optical system and the high-magnification optical system each have telecentricity. The distortion of the work in the work image acquired by the telecentric optical system is very small as compared with the distortion of the work in the work image acquired by the non-telecentric optical system. Therefore, the workpiece is measured with high accuracy. The low-magnification optical system and the high-magnification optical system do not have to have telecentricity.

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 adopted. The optical axis of the irradiation light of the coaxial epi-illumination 130 coincides with the imaging axis. The coaxial epi-illumination 130 has a light source 131 arranged so as to output illumination light in the horizontal direction, and a half mirror 132 that bends the illumination light emitted from the light source 131 downward. The illumination light of the coaxial epi-illumination 130 is advantageous when acquiring irregularities and patterns on the work surface.

Further, a ring illumination 180 is provided around the light receiving lens 114. The stage drive unit 181 moves the ring illumination 180 up and down. As a result, the irradiation angle of the illumination on the work can be adjusted, and the way the edges stand out can be adjusted.

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

The transmitted illumination 150 is an illumination device that irradiates the work on the movable stage 12 with illumination light from below. The transmission illumination 150 includes a light source 151, a mirror 152, and a condensing lens 153. The light source 151 is arranged so as to output illumination light in the horizontal direction. The 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 work. A part of the illumination light is blocked by the work, and the other part of the illumination light is incident on the light receiving lens 114. The illumination light of the transmitted illumination 150 is advantageous in acquiring the edge of the outer shape of the work.

An LED (light emitting diode) or a halogen lamp is used as each light source of the coaxial epi-illumination 130 and the transmission illumination 150.

The bird's-eye view camera 17 is an imaging device used to acquire a bird's-eye view image of the movable stage 12. The bird's-eye view image is an image that includes almost the entire movable stage 12. The imaging field of view of the bird's-eye view camera 17 is wider than the imaging field of view of the low-magnification camera 110 and the high-magnification camera 120. Therefore, the bird's-eye view camera 17 is suitable for acquiring an image in a wider range as compared with the low-magnification camera 110 and the high-magnification camera 120. On the other hand, the telecentricity of the bird's-eye view camera 17 is lower than that of the low-magnification camera 110 and the high-magnification camera 120. Therefore, the bird's-eye view camera 17 may be called a non-telecentric camera. Since the shape of the work is distorted in the work image acquired by the bird's-eye view camera 17, the bird's-eye view camera 17 is not suitable for measuring the work as compared with the low-magnification camera 110 and the high-magnification camera 120. The field of view of the optical system is circular, and the subject in the field of view forms an image circle to form an image on the image sensor. On the other hand, the range that the image sensor can image is rectangular. That is, the imaging region is a partial rectangular region in the image circle. Here, the rectangular region on the movable stage 12 corresponding to the imaging region of the image sensor is called the imaging field of view.

<Overhead camera>
As shown in FIG. 2, the light receiving lens 114 covers a considerable part of the 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 view camera 17 when the bird's-eye view camera 17 is viewed from the front side of the measurement unit 10. W indicates a work. In this example, the bird's-eye view camera 17L is arranged on the left side of the light receiving lens 114, and the bird's-eye view camera 17R is arranged on the right side of the light receiving lens 114. R1 indicates the field of view of the low magnification camera 110. R2L indicates the field of view of the bird's-eye view camera 17L. R2R indicates the field of view of the bird's-eye view camera 17R. By adopting two bird's-eye view cameras 17R and 17L, most parts of the movable stage 12 can be imaged at once. Nevertheless, on the movable stage 12, there is a blind spot range R2L that cannot be covered by the field of view range R2L of the bird's-eye view camera 17L and the field of view range R2L of the bird's-eye view camera 17L.

FIG. 3B is a diagram illustrating a method of capturing an image of the work W arranged near the center of the movable stage 12 with the bird's-eye view camera 17. By moving the movable stage 12 so that the optical axis of the bird's-eye view camera 17R coincides with the center of the movable stage 12, a bird's-eye view image of the work W arranged near the center of the movable stage 12 can be obtained. Although the bird's-eye view camera 17R is used here, the bird's-eye view camera 17L may be used.

It should be noted that the bird's-eye view image acquired by the bird's-eye view camera 17L in FIG. 3 (A), the bird's-eye view image acquired by the bird's-eye view camera 17R, and the bird's-eye view image acquired by the bird's-eye view camera 17R in FIG. 3 (B) are combined. A composite bird's-eye view image that covers the entire movable stage 12 may be created. Although it is not possible to create a composite bird's-eye view image in real time, if real-time performance is not required, a composite bird's-eye view image can be created.

FIG. 3A illustrates an example in which the blind spot range R3 of the two bird's-eye view cameras 17R and 17L is generated. However, depending on the angle of view and installation position of the two bird's-eye view cameras 17R and 17L to be adopted, there may be a case where the blind spot range R3 does not exist and the entire movable stage 12 can be imaged at once.

<Correction member for correcting the 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. Further, since these have temperature-dependent characteristics, they change depending on the environment in which the measurement unit 10 is installed. The position of the feature of the work W extracted from the low-magnification image and the position of the feature of the work W extracted from the high-magnification image should be the same, but there may be a gap between them. .. Therefore, position correction information for correcting the position of the feature of the work W extracted from the low-magnification image and the position of the feature of the work W extracted from the high-magnification image is required.

As shown in FIG. 2, the correction member 19 is fixed to the back surface of the light transmitting plate 13. The correction member 19 may be provided at any position within the range ZR from the surface of the light transmitting plate 13 to the transmitted illumination 150. When the front surface of the light transmitting plate 13 may be imaged for measuring the height of the work W, the range ZR may be changed to a range from the back surface of the light transmitting plate 13 to the transmitted illumination 150. The correction member 19 may be provided inside the light transmitting 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 as a reference for position correction.

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 light transmitting 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 the normal measurement operation and is not used for the 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 means a range in which the camera head 103 moves up and down by the stage drive unit 101Z. It is also conceivable that the correction member 19 is arranged inside the camera head 103. In particular, arranging the correction member 19 (pattern) for correction in the lens constituting the optical system of the light receiving system lens is highly difficult in manufacturing and high in cost.

On the contrary, when the correction member 19 is arranged below the surface of the light transmitting plate 13, the correction member 19 is easily arranged and the cost is relatively low. Even if the user is observing the work W within the measurement range, it is desirable that the pattern is sufficiently blurred so that the pattern does not interfere with the observation. That is, if the pattern is arranged at a position sufficiently distant from the mounting surface of the movable stage 12, the pattern is sufficiently blurred. As a result, the pattern given to the correction member 19 is less likely to affect the normal use (when measuring the work W).

When the correction member 19 is arranged on the surface of the light transmitting plate 13, the pattern of the correction member 19 is less likely to be blurred because the focus may be on the vicinity of the surface of the light transmitting plate 13. For example, when trying to focus on a short work W, the correction member 19 formed on the surface of the light transmitting plate 13 may be in focus.

Further, when the correction member 19 is provided on the surface of the light transmitting plate 13, since the work W is mounted, the correction member 19 is easily damaged by the work W. Dust tends to adhere to the correction member 19, and the accuracy of correction may decrease.

Therefore, by arranging the correction member 19 on the back surface of the work W, which is not used in normal measurement, the area that is not normally used is effectively utilized for correction. Further, the correction member 19 does not interfere with the normal measurement. 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 back surface of the light transmitting plate 13.

The image measuring device 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 device 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 illustrating the function of the controller 60 mounted on the control unit 20. FIG. 5 shows an optional function required when generating the bird's-eye view image 41. The controller 60 is composed of a processor (eg, CPU or the like) and controls the measurement unit 10. CPU is an abbreviation for central processing unit. Some or all of the functions of the controller 60 may be realized by hardware such as an ASIC or FPGA. ASIC is an abbreviation for a special purpose integrated circuit. FPGA is an abbreviation for field programmable gate array. The illumination control unit 81 is mounted on the control unit 20 or the measurement unit 10 and controls the illumination unit 84 (coaxial epi-illumination 130 and transmission illumination 150) according to a control signal from the controller 60. The image pickup control unit 82 is mounted on the control unit 20 or the measurement unit 10 and controls the camera unit 85 (low-magnification camera 110, high-magnification camera 120, and bird's-eye view cameras 17R, 17L) according to a control signal from the controller 60. The storage device 70 has a memory, a hard disk drive, and the like, 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 work W according to the user input input from the keyboard 31 or the like. The setting data 71 includes, for example, setting information regarding pattern search (positioning) of the work W, setting information regarding measurement points, non-defective product threshold value, imaging conditions (imaging magnification and lighting conditions), and the like.

The measurement control unit 62 lights one of the lighting units through the lighting control unit 81 according to the setting data 71, or causes any camera unit to perform imaging through the image pickup control unit 82.

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

The search unit 66 executes a pattern search on the target image acquired by the low-magnification camera 110 based on the setting data 71, and identifies the position and posture of the work W. For example, the search unit 66 compares the reference image included in the setting data 71 with the target image, obtains the amount of displacement of the target image and the amount of deviation of the posture with respect to the reference image, and the amount of deviation of the position and the posture. A conversion formula for the coordinates of the measurement point is generated from the amount of deviation 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 work W to be measured are determined. Further, the search unit 66 converts the coordinates of each measurement point into the machine coordinates of the imaging position corresponding to each measurement point. The search unit 66 obtains the shortest path (imaging order) for imaging all the machine coordinates of the imaging positions of the plurality of measurement points. The measurement control unit 62 sets the machine coordinates of each measurement location in the stage drive unit 101XY according to the imaging order, and drives the movable stage 12. Further, the image pickup control unit 82 applies the image pickup conditions (imaging magnification and illumination conditions) based on the setting data 71 for each measurement point to the illumination unit and the camera unit to perform imaging. For example, if the imaging magnification is low, the imaging control unit 82 causes the 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 location. In this way, a work image for each measurement point is generated.

The measuring unit 67 executes various measurements related to the work W from the work image according to the setting data 71. The work image may be a connected image 42 generated by connecting a plurality of low-magnification images or high-magnification images for each measurement point, or a single low-magnification image or high-magnification image for each measurement point. It may be. The measuring unit 67 has a plurality of measuring tools. Multiple measurement tools include line-line distance measurement tools that measure the distance between one line and another, point-line distance measurement roots that measure the distance between one point and another, and some lines. A squareness measuring tool for measuring the squareness with another line may be included. The measuring unit 67 recognizes these points and lines as edges in the image, and executes measurement based on the edges. For example, the measuring unit 67 performs dimensional measurement using one or a plurality of edges included in the work image. The measuring unit 67 may execute the dimensional measurement using a predetermined edge included in the first low-magnification image and a predetermined edge included in the second low-magnification image. The measuring unit 67 may execute the dimensional measurement using a predetermined edge included in the first high-magnification image and a predetermined edge included in the second high-magnification image. The measuring unit 67 may execute the dimensional measurement using a predetermined edge included in the low-magnification image and a predetermined edge included in the high-magnification image. The measuring unit 67 may compare the measurement result with the non-defective product threshold value and 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 executes various measurements using the position of the edge corrected by the position correction unit 69.

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

<Flowchart>
FIG. 5 is a flowchart showing a main process executed by the controller 60 when the power switch 15 is switched on.

In S500, the controller 60 (creating 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 (factory default) of the measurement unit 10. When the power switch 15 is switched on and the controller 60 is activated, the controller 60 (creating unit 68) executes the creation process (update process) to create the position correction information 44, which is stored in the storage device 70. The position correction information 44 is updated. The position correction unit 69 corrects at least one of the coordinates related to the low-magnification image and the coordinates related to the high-magnification image based on the position correction information 44. As a result, the position of the feature of the work W extracted from the low-magnification image and the position of the feature of the work W extracted from the high-magnification image become the same.

In S501, the controller 60 determines whether or not the setting mode is 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 is 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 S503, the controller 60 determines whether or not the measurement mode has been selected by the user through the operation unit 30. If the measurement mode is not selected, the controller 60 returns to S501. On the other hand, if the measurement mode is selected, the controller 60 proceeds to S504.

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

In S505, the controller 60 (measurement control unit 62) executes the continuous measurement mode. Details of the continuous measurement mode will be described later with reference to FIG. 7.

● Setting mode FIG. 6 is a flowchart showing the setting mode.

In S601, the controller 60 uses the bird's-eye view camera 17 to generate a bird's-eye view image. This bird's-eye view image may be used in the setting mode or in the measurement mode. In particular, the bird's-eye view image will be useful in roughly positioning the work W with respect to the movable stage 12. If the bird's-eye view image is not used, S601 is omitted.

FIG. 8 shows a user interface 160a for displaying the bird's-eye view image IM01. The bird's-eye view image IM01 here is generated by using the bird's-eye view 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 view camera 17R, and causes the bird's-eye view camera 17R to perform imaging to generate a bird's-eye view image IM01 and display it on the display device 11. To do. When the bird's-eye view image IM01 acquired in S601 is used in the setting mode or the measurement mode, the bird's-eye view image IM01 is held in the storage device 70.

In S602, the controller 60 (image connecting unit 64) generates a connected image of the work W. In order to set the measurement point for each measurement tool for the work W, it is convenient for the user to have an image showing almost the entire work W. However, it takes an enormous amount of time to create a connected image while scanning the entire movable stage 12 using the low-magnification camera 110 or the high-magnification camera 120. Normally, the area of the work W in a 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 a plurality of low-magnification images while moving the movable stage 12 so as to follow the edge (outer edge) of the work W. To generate. Further, the controller 60 (image connecting unit 64) generates a connected image representing almost the entire work W by connecting a plurality of low-magnification images. Each low-magnification image is taken with both epi-illumination and transmitted illumination, which will be described later. That is, a low-magnification image is acquired with epi-illumination turned on and transmitted illumination turned off, and another low-magnification image is acquired with epi-illumination turned off and transmitted illumination turned on. A concatenated image is generated by concatenating a plurality of low-magnification images acquired by using epi-illumination, and this concatenated image has texture information on the surface of the work W. On the other hand, another connected image is generated by concatenating a plurality of low-magnification images acquired by using transmitted illumination, and the edge of the contour portion of the work W is cleared in this other concatenated image.

FIG. 9 shows the user interface 160b displayed on the display device 11 during the generation of the linked image. In particular, FIG. 9 shows an example of connecting low-magnification images taken by 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 connecting unit 64 associates the generated low-magnification image IM02 with an 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 work W on the display device 11.

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

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

The concatenated image generated to include the entire work 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 to accept the setting of the measurement location. The 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 a measurement tool from the tool selection unit 163a, selects an imaging magnification from the magnification selection unit 163b, and selects the type and brightness of illumination (illumination conditions) from the illumination selection unit 163c. When the illumination control unit 81 has a function of automatically adjusting the amount of light, the selection of brightness may be omitted. The user specifies the measurement point 162a by selecting the edge to be extracted in the connected image. The setting unit 61 controls the image pickup control unit 82 and the illumination control unit 81 so as to perform imaging on the measurement point 162a at the magnification and the illumination condition selected by the user. As the lighting condition, any one of epi-illumination, transmission illumination, and ring illumination can be selected. Ring lighting can be moved up and down. When ring lighting is selected, the user can set the vertical position of the ring lighting. The lighting conditions may be automatically set based on the sharpness (contrast) of the edge selected by the user. Further, the focal position (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 superimposes and displays the image acquired at the selected magnification, the illumination condition, and the automatically adjusted focal position for the measurement point 162a on the connected image IM03. The user visually confirms that the edges are properly extracted. In this example, since low magnification and transmitted illumination are selected, the image acquired for the measurement point 162a is a transmitted illumination image in which the edge of the outer edge of the work W is emphasized. The user sets the edge 164a, which is a reference of the distance measured by the selected measurement tool, by operating the pointer 161. In this example, since the length measuring tool is selected, the length from a certain reference point (eg, another edge, the center of a circle, etc.) to the edge 164a is measured. Although not shown in FIG. 11, the setting unit 61 also accepts the setting of the measurement point serving as the reference point. The setting unit 61 assigns identification information to each measurement location, associates the selected measurement tool type (measurement content), the position of the measurement location, and the like, and creates setting data.

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

FIG. 13 shows a user interface 160e for executing the enlarged display of the measurement point 162b. The setting unit 61 displays the user interface 160e when it detects that the measurement point 162b is clicked by the pointer 161. For the high-magnification image IM04 corresponding to the measurement point 162b, the user operates the pointer 161 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 instruction of the user. Therefore, in this example, the squareness of the edge 164a shown in FIG. 12 and the edge 164b shown in FIG. 13 is measured. The setting unit 61 assigns identification information to each measurement point and associates the type (measurement content) of the selected measurement tool, the position of the measurement point, and the like. The measurement point may be composed of a plurality of edge extraction points or may be composed of one edge extraction point. As the measurement points composed of one edge extraction point, for example, there are a measurement point for measuring the diameter of the hole and a measurement point for measuring the roundness of the hole.

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

FIG. 14 shows a user interface 160f that accepts pattern search settings. The work determination unit 63 generates a transmission illumination image together with the epi-illumination image when creating the connection image IM03, and connects a plurality of transmission illumination images to generate the connection image IM05. The user interface 160f has a display area for the connected image IM05. The setting unit 61 accepts the setting of the search area 166 on which the pattern search is executed and the registration area 167 of the reference image. The search area 166 may be referred to as an imaging range. The setting unit 61 saves the coordinates of the search area 166 and the coordinates of the registration area 167 designated by the user in the connected image IM05 in the setting data 71. The setting unit 61 extracts the image included in the registration area 167 as a reference image. The reference image includes features relating to the shape of the work W used in the 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 the measurement point information in a RAM or the like of the storage device 70. The measurement point information is used to determine the measurement point in the work image acquired for each work 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 or the like of the storage device 70 as a part of the reference imaging position information.

In S608, the controller 60 (setting unit 61) stores the reference image, the reference imaging position information, the measurement location information, the 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 association between the measurement location and each shooting condition using the work of the use case)
FIG. 23A is a diagram showing a plan view of the work W for explaining an example of the setting data stored in the storage device. FIG. 23B is a diagram showing a side view of the work W corresponding to the setting data. FIG. 23C shows the magnification, the illumination condition, and the focal position at each measurement point in the set data. The measurement point 2301a is a hole that does not penetrate. Since the edge of the measurement point 2301a cannot be extracted by the transmitted illumination, the epi-illumination is set. When the measurement point 2301a is small, edge extraction cannot be performed with sufficient resolution at a low magnification. Therefore, the magnification is set to a high magnification. The focusing 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 work W, transmitted illumination is set and selected. Further, for such a contour, an edge with sufficient accuracy can be extracted even at a low magnification, so that the magnification is set to a low magnification. The focusing position for the measurement point 2301b is automatically set to Z1 as in the measurement point 2301a.

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

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

● Measurement mode FIG. 7 is a flowchart showing a 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 work W.

15A and 16 show a user interface 160g containing guidance information for assisting or guiding the user to place the work W. In the user interface 160g, the bird's-eye view images IM01a and IM01b, which are live images, and the bird's-eye view images IM01a and IM01b acquired in the setting mode are superimposed and displayed. In this example, the work W1 shows the work image acquired in the setting mode, and the 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 also moves. The alignment frame 171 is a frame corresponding to the search area 166. The alignment frame 171 is fixed to the bird's-eye view 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 in the alignment frame 171 or the work W2 overlaps the work W1. The measurement control unit 62 may assist the positioning of the work W2 by displaying the bird's-eye view images IM01a and IM01b acquired in the setting mode semi-transparently. As described above, the image of the alignment frame 171 and the work W1 is an example of guidance information for assisting or guiding the user to place the work W.

In S702, the controller 60 (measurement control unit 62) determines whether or not the measurement start is instructed. For example, when the execution button 16 is pressed, the measurement control unit 62 determines that the measurement start is instructed. If the measurement start is not 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, a low-magnification image is 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 matching the reference image is searched for. Therefore, it took a long time to search the pattern. On the other hand, in the present invention, since the imaging position (machine coordinates) of the search area 166 is stored in the preset data 71 in advance, the search unit 66 immediately moves the movable stage 12 to the imaging position of the search area 166. Can be done. That is, the imaging process for searching the search area 166 and the repeated movement of the movable stage 12 are not required. When the user who made the setting and the user who performs the measurement match, the user remembers a predetermined position on which the non-defective work is placed on the movable stage 12 in the setting mode. Therefore, the user can position each work to be measured at a predetermined position based on his / her own memory. On the other hand, usually, the user who made the setting and the user who made the measurement do not match. In this case, it will be difficult for the user who executes the measurement to position each work in a predetermined position. Therefore, the measurement control unit 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 arrangement of the work W in the setting mode. That is, in the imaging position (machine coordinates) of the search area 166 determined in the setting mode, there is a high probability that a feature for positioning extracted from the reference image exists. As a result, the pattern search will be completed in a short time.

Further, the bird's-eye view image acquired in the setting mode and the current bird's-eye view image may be displayed semi-transparently at the same time. As a result, it is possible to guide the user to place the work W so that the pattern search is successful. When the two translucent images overlap, the position and orientation of the work W in the setting mode and the position and orientation of the current work W are the same, so that the feature portion of the work is automatically included in the search area.

In the present embodiment, the guidance information for assisting or guiding the placement of the work W includes the above-mentioned alignment frame 171 and the semi-transparent display of the bird's-eye view image.

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

Once the pattern search is successful, the preset measurement points can be identified. Therefore, each measurement point is photographed in order at preset magnifications, lighting conditions, and focusing positions, and the measurement can be completed in a short time.

In the above embodiment, an example in which one search area 1502 is set is shown, but 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 the pattern search. The user interface 160h generated by the search unit 66 or the measurement control unit 62 displays the low-magnification image IM06 acquired as the target image by using the low-magnification camera 110. The thumbnail image IM06'is a thumbnail image of the reference image acquired in the setting mode. The user can confirm that the pattern search is executed correctly by comparing these images.

In S705, the controller 60 (search unit 66) executes a pattern search on the target image using the reference image included in the setting data 71. The search unit 66 obtains the amount of displacement of the work W2 to be measured with respect to the reference image in the X direction, the amount of displacement of the position in the Y direction, and the posture (rotation angle in the XY plane). S720 and S721 may be inserted between S705 and S706.

In S720, the controller 60 (search unit 66) determines whether or not the pattern search is 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 a notification (screen) on the display device 11 prompting the user to place the work W in the correct position and posture. After that, the controller 60 returns to S704. Alternatively, the controller 60 may transition to the automatic search mode in which the work W is automatically searched. The controller 60 repeats shooting while regularly moving the movable stage 12 until the work W enters the field of view. When the work W is captured in the field of view, the controller 60 repeats shooting 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 identifies the measurement location by executing a pattern search on the connected image of the work W.

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 the 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 corrects the coordinates of each measurement point included in the measurement point information based on the result of the pattern search (position and posture for each work), and further, the position-corrected coordinates are 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 be the shortest route.

In S708, the controller 60 (measurement control unit 62) controls the movable stage 12 and the camera unit based on the determined measurement order and the imaging setting information to acquire an image. If the image pickup setting information specifies a high magnification, the high magnification camera 120 images the work W. If the image pickup setting information specifies a low magnification, the low magnification camera 110 images the work W. Further, the measurement control unit 62 lights any one of the coaxial epi-illumination 130, the transmission 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 captured. The high-magnification camera 120 and the low-magnification camera 110 have a bifurcated optical system with a half mirror, and can simultaneously acquire a high-magnification image and a low-magnification image. Therefore, the image of the magnification associated with each measurement point is acquired at high speed only by moving the movable stage 12. In order to acquire a plurality of images having different magnifications, an image measuring device such as a revolver or a zoom lens may be adopted. In this case, it takes time to change the magnification with a revolver or a zoom lens, but since a bifurcated optical system is used, a high-magnification image and a low-magnification image can be acquired at the same time, and the time required for shooting will be shortened.

18 and 19 show the user interface 160i displayed during the imaging process. In FIG. 18, the measurement control unit 62 may display the display area for displaying the image IM07 of the measurement point acquired at each measurement point and the display area for displaying the enlarged image IM07'of the image IM07 on the user interface 160i. Good. In this example, the image IM07 is a low magnification image. In FIG. 19, the measurement control unit 62 may display the display area for displaying the image IM08 of the measurement point acquired at each measurement point and the display area for displaying the enlarged image IM08'of the image IM08 on the user interface 160i. Good. In this example, the 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 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 S709, the controller 60 (measurement unit 67) executes dimensional measurement for each measurement point based on the images IM07 and IM08 and the measurement point information, and stores the measurement result in the storage device 70. For example, the measuring unit 67 extracts an edge from each predetermined location by using a measuring tool according to the measurement location information, and measures the distance, diameter, squareness, roundness, etc. with the edge as a reference. The measurement location information may include a threshold value such as a tolerance that serves as a reference for a 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.

20 to 22 show a user interface 160j for displaying the measurement result. In FIG. 20, the user interface 160j has an image display area 168 and a result display area 169. The image display area 168 is an area for displaying the work images IM09 to IM11 acquired in S708. The work images IM09 and IM10 are low-magnification images. The work image IM 11 is a high-magnification image. As described above, in the present invention, since the image is acquired only at the position necessary for the measurement in the movable stage 12, the measurement time is shortened. The measurement unit 67 may display the numerical information 170 indicating the measurement result and the content information 172 indicating the measurement content together with the low-magnification image and the high-magnification image. The content information 172 may include, for example, information indicating the start and end points of the measured distance. Further, the content information 172 may include a bidirectional arrow or the like meaning a distance. Further, the content information 172 may include a unit (eg, millimeter, etc.) indicating a measurement result. The result display area 169 includes identification information of the measurement location (example: 1, 2, ...), measurement content (example: line-line distance), measurement result (example: 114.368 mm), and pass / fail judgment result (example). : OK / NG) etc. are displayed.

As shown in FIG. 20, the controller 60 can measure the dimensions between the edges extracted from the high magnification image and the edges 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.

On the back surface of the translucent plate 13 provided on the movable stage 12, a correction member to which an optical mark as a reference for position correction is given may be provided. The controller 60 images the optical mark with both the high-magnification camera 120 and the low-magnification camera 110, and corrects the position of the high-magnification camera 120 and the position of the low-magnification camera 110. The position correction method 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 mounted on the movable stage 12. The controller 60 may correct the position of the high-magnification camera 120 and the position of the low-magnification camera 110 based on the amount of deviation of the positions of the position correction marks shown in the two images.

In the present invention, an image is acquired only at a position necessary for photographing a measurement point. Therefore, the position of the image acquired at the time of measurement is a discrete position with respect to the connected image of the work W acquired in the setting mode. The image is acquired in the measurement mode only for a part of the connected images acquired in the setting 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. That is, a plurality of images are arranged discretely, and it is difficult for the user to understand which position of the measurement result is displayed in the entire work W. Therefore, in the present embodiment, as shown in FIG. 21, the work images IM09 to IM11 acquired in the measurement mode are superimposed and displayed on the connected image IM03 acquired in the setting mode in the image display area 168. Will 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. Further, the connected image 42 is read from the storage device 70 even in the measurement mode, and the measurement result is superimposed and displayed on the connected 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 quality judgment result, a measured value, a symbol indicating a position where the measurement is executed, and the like. When displaying the symbol, the measured value may be displayed in a display area different from the display area in which the connected image 42 is displayed.

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

Further, in the present invention, in the measurement mode, the low-magnification image or the high-magnification image acquired at each measurement point is superimposed and displayed on the connected image. As a result, in the connected image, only the measurement point is displayed by being replaced or superimposed on the image actually acquired in the measurement mode. Therefore, when the desired measurement result is not obtained, the user can confirm the actual image acquired in the measurement mode. As a result, the user will be able to visually understand the reason why the desired measurement result was not obtained.

FIG. 24 is a detailed flowchart of S710. When the controller 60 executes the measurement based on the measurement location information and the acquired image in S709, the process proceeds to S2401. In S2401, the controller 60 reads out the connected image 42 stored in the storage device 70 and acquired in advance in the setting mode. In S2402, the controller 60 determines the display position of the measurement result based on the pattern search result obtained in S705. In S2403, the controller 60 superimposes the captured image obtained in the measurement mode and the measurement result on the connected image 42 obtained in the preset mode (example: FIG. 21).

The connected image IM03 acquired in the setting mode may be displayed in the image display area 168, and the work images IM09 to IM11 acquired in the measurement mode may not be displayed.

As shown in FIG. 22, the measuring unit 67 may magnify and display the work image IM11 of the measurement point designated by the user. When a specific measurement point is clicked by the pointer 161, the measurement unit 67 displays the work image IM 11 corresponding to the clicked measurement point in the image display area 168. This will make it easier for the user to ensure that the correct edge is being measured.

<Details of position correction>
When measuring the work, the surface of the work located higher than the mark-imparting surface in the Z direction is measured. That is, when measuring the work, the mark is blurred, so that the mark does not easily affect the measurement of the work. From this point of view, the cross-shaped mark is superior to the dot-shaped mark.

Conventionally, it was necessary to set a chart for correction on a mounting table or the like, but in this embodiment, such a chart is unnecessary. The user can perform position correction by using the stage glass as it is, which is very convenient.

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

● Position Correction Member and Mark FIG. 25 (A) shows a plurality of marks M added to the correction member 19 in a grid pattern. The pitch of the mark M is, for example, 1 mm. When a circular mark is adopted as the mark M, its diameter may be 30 um. FIG. 25B shows a cross-shaped mark M attached to the correction member 19. It should be noted that dust and the like are likely to adhere to the light transmitting plate 13. Therefore, in order to distinguish between the dust and the mark M, a device for the shape of the mark M or a device for image processing (dust removal processing) may be adopted.

FIG. 26A is a diagram showing the structure of the correction member 19. The correction member 19 may be a film capable of laser marking. The correction member 19 has an adhesive layer for attaching the correction member 19 to the back surface of the light transmitting plate 13. A matte material layer is provided below the adhesive layer. The mat material layer may have silica grains having a diameter of 2 um or more and 7 um or less. A gelatin layer is provided below the mat material layer. Another matte layer is provided below the gelatin layer. This mat material layer may also have silica grains having 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 laser light (laser marking).

FIG. 26B is a diagram showing another structure of the correction member 19. Compared with FIG. 26 (A), in FIG. 26 (B), a photosensitive layer is provided between the adhesive layer and the upper matte material layer. In FIG. 26B, when autofocus is performed, the mark M and the matte material layer at the bottom are in focus. The matte material layer generally contains silica particles, and the silica particles are in a state of contrast when viewed in an image. On the other hand, in FIG. 26 (A), since the adhesive layer covers the silica particles and is integrated in terms of material, it is difficult to focus only on the mark M. Therefore, the structure shown in FIG. 26 (A) would be preferable.

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

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

In S2502, the controller 60 (creating unit 68) determines whether or not there is an obstacle (eg, a work or the like) in 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 transmission 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 has an area of a group of black pixels. Ask for (so-called blob). Further, the creating unit 68 compares each blob with the threshold value and determines whether or not there is a blob equal to or larger than the threshold value. If there is a blob above the threshold, the controller 60 proceeds to S2512 because there is an obstacle in the field of view. In S2512, the controller 60 (creating unit 68) controls the stage driving unit 101XY and moves 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 (creating unit 68) may output a warning. For example, the creating unit 68 may display a warning message on the display device 11 to warn the user not to place a work or the like on the light transmitting plate 13. In this way, the creation unit 68 has an obstacle avoidance unit or a warning output unit. After that, the controller 60 returns to S2502. If there are no blobs above the threshold, the controller 60 proceeds to S2503 because there are no obstacles in the field of view.

In S2503, the controller 60 (creating unit 68) acquires a low-magnification image and a high-magnification image by using the transmission illumination 150. In this way, the creating unit 68 may have an image acquisition unit. The image acquisition unit turns on the transmission illumination 150 via the illumination control unit 81 and turns off the coaxial epi-illumination 130. Further, the image acquisition unit causes the low-magnification camera 110 and the high-magnification camera 120 to perform imaging via the image pickup control unit 82, respectively. The image pickup control unit 82 controls the stage drive unit 101Z so that the mark M is in focus.

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

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

FIG. 28 shows a low-magnification image IM15 and a high-magnification image IM16 in which dust D is reflected. The blob of garbage D is much larger than that of mark M. Since the blob of the dust D exceeds the upper limit, the dust D is distinguished from the mark M.

Further, 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 defined in advance based on the mark M for the length of the blob in the X direction. Further, 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 defined in advance based on the mark M for the length of the blob in the Y direction. In FIG. 28, the length of the dust D in the X direction exceeds the upper limit value. Further, the length of the dust D in the Y direction also exceeds the upper limit value. Therefore, garbage D is excluded.

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

Further, the creating 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 this distance with a predetermined upper limit value and lower limit value. You may narrow down the candidates. In this way, the creating unit 68 may have a distance determining unit. When dust having the same shape and area as the mark M adheres, it is difficult to distinguish the mark M from the dust or the like only by the shape and the area. Therefore, the creating unit 68 may select candidates by 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 reflected. In this example, since the size of the dust D is the same as that of the mark M, it is not possible to distinguish the mark M from the dust or the like only by the shape and the area. Further, 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 this distance is equal to or less than a predetermined upper limit value and is greater than or equal to the lower limit value, so that the dust D can be excluded. Good.

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

In S2507, the controller 60 (creating unit 68) determines the positions of the mark M candidate extracted from the high-magnification image and the mark M candidate positions extracted from the low-magnification image for each pair registered in the pair list. Find the amount of deviation (XY coordinates and angle). In this way, the creation unit 68 may have a deviation amount calculation unit.

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

In S2509, the controller 60 (creating unit 68) obtains a statistical value (example: average value) of the amount of deviation of the pairs remaining in the pair list. In this way, the creation unit 68 may have a statistical value calculation unit.

In S2510, the controller 60 (creating unit 68) determines whether or not the statistical value of the deviation amount has been obtained for N measurement positions. The N measurement positions may be arranged so as to substantially cover the entire light transmitting plate 13, for example. Further, N may be 1. The larger N is, the more accurate the position correction information is. The smaller N is, the shorter the processing time of the creation process is. If the deviation amount statistical value is not obtained for N measurement positions, the controller 60 proceeds to S2513. In S2513, the controller 60 controls the stage drive unit 101XY and moves 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. When the statistical value of the deviation amount is obtained for N measurement positions, the controller 60 proceeds to S2511.

In S2510, the controller 60 (creating 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 sets at least one of the position extracted from the low-magnification image and the position extracted from the high-magnification image so that the position extracted from the low-magnification image and the position extracted from the high-magnification image match. Create position correction information for correction. The creation 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. Further, the position correction information obtained at the time of shipment from the factory may be retained without being erased.

In the method according to the comparative example, the position correction is executed at a timing different from the timing of measuring the work and the execution timing of the setting required for executing the measurement of the work. That is, a dedicated member for position correction must be placed on the mounting table, and the position information between the low-magnification image sensor and the high-magnification image sensor must be adjusted. On the other hand, by using the correction member 19 as in the present embodiment, it is possible to adjust the position information together at the timing of measuring the work or the timing of setting. In other words, the burden on the user will be reduced by eliminating the need for separate adjustment work. Further, the position correction is executed by using the correction member 19 provided in the image measuring device 1. Therefore, it is not necessary 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 capturing a work at a low magnification to generate a low-magnification image and an optical axis coaxial with the optical axis of the low-magnification optical system, and the work is higher than the low magnification. This 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 drive unit 101XY is an example of a drive 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 relatively in the XY direction. is there. The controller 60 controls the driving unit and the imaging unit, generates a plurality of low-magnification images or high-magnification images for different parts of the workpiece, and connects the generated plurality of low-magnification images or high-magnification images. Acts as a processor that generates images. The storage device 70 functions as a memory for storing the connected image. As described in connection with 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 linked image, or a position specified by the user in the linked image by the imaging unit. The reference image for pattern search generated by the above may be stored in the memory. The processor may store the measurement point information indicating a plurality of measurement points specified by the user in the connected image in the memory. 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 connected image. The imaging position information is determined in the measurement mode from the relative position of the measurement point included in the measurement point information and the result of the pattern search. That is, the processor may store in the memory the imaging position information indicating the imaging position of the imaging unit for imaging each of the plurality of measurement points by the imaging unit. For example, the imaging position may be represented by the machine coordinate system of the movable stage 12. In the setting mode, the processor may store the imaging setting information indicating which magnification of the low magnification and the high magnification the imaging position is to be imaged in the memory. As described in connection with FIG. 7 and the like, in the measurement mode, the processor controls the imaging unit, acquires the target image of the pattern search, and uses the reference image of the pattern search stored in the memory to perform the pattern. Perform a pattern search on the image to be searched. The processor identifies a plurality of imaging positions for imaging each of the plurality of measurement points based on the measurement point information associated with each of the plurality of measurement points stored in the memory and the result of the pattern search. That is, the position information relative to each measurement point with respect to the reference imaging position is converted into absolute imaging position information. Further, the processor drives at least one of the mounting table and the imaging unit to the driving unit to sequentially set the imaging position of the imaging unit to each of the plurality of imaging positions, and images 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 location. The processor measures the dimensions of the measurement points 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 a magnification specified for each measurement location, the number of imaging times in the measurement mode is reduced, and image measurement can be performed efficiently. Further, since it is not essential that the imaging is performed at the measurement point and the imaging is performed over the entire work, the number of imagings is reduced. Dimension measurement is executed every time a work is placed on the movable stage 12. Therefore, reducing the number of imagings for each work improves the efficiency of dimensional measurement.

The transmitted illumination 150 is provided below a mounting table that is at least partially translucent. The transmission illumination 150 functions as a transmission illumination unit that irradiates the work mounted on the mounting table with the transmission illumination light. The transmitted illumination light is light that goes from the bottom to the top of the mounting table. The camera unit 85 receives the transmitted illumination light output from the transmitted illumination 150 that is not blocked by the work. Therefore, the outline (outer edge) of the work is emphasized in the work image. Therefore, the transmitted illumination light is advantageous for measuring the dimensions of the outer shape of the work. The coaxial epi-illumination 130 and the ring illumination are provided above the mounting table and function as an epi-illumination unit that irradiates the work mounted on the mounting table with the epi-illumination light. For example, in the setting mode S606 or the like, the processor may store in the memory the illumination conditions indicating whether to use the transmission illumination unit or the epi-illumination unit for each of the plurality of measurement points. Illumination conditions may be included in the imaging setting information. In the measurement mode, the processor turns on the illumination unit of the transmission illumination unit and the epi-illumination unit according to the illumination conditions stored in the memory for each of the plurality of measurement points. Since the illumination conditions are set for each measurement location in this way, different illumination lights can be applied to each measurement location. This will improve the measurement accuracy of dimensions.

The low-magnification camera 110 is an example of a low-magnification image sensor that images a work via a low-magnification optical system. The high-magnification camera 120 is an example of a high-magnification image sensor that images a workpiece via a high-magnification optical system. As shown in FIG. 2, the low-magnification optical system and the high-magnification optical system may form a branched optical system having the same optical axis. The memory may store position correction information that corrects the relationship between the position of the low-magnification image generated by the low-magnification image sensor and the position of the high-magnification image generated by the high-magnification image sensor. 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 the low-magnification camera 110 and the high-magnification camera 120 have an assembly error, the position of the work extracted from the low-magnification image and the position of the work extracted from the high-magnification image may not match. Further, an error occurs in these positional relationships depending on the temperature of the installation environment of the measurement unit 10. Therefore, the accuracy of the dimensional measurement is improved by performing the position correction. In particular, position correction will be important in the case of measuring the distance from the feature (edge) extracted from the low-magnification image to the feature (edge) extracted from the high-magnification image.

The display device 11 is an example of a display device that displays an image of a work. In the measurement mode, the processor may display the low-magnification image and the high-magnification image of the images including a part of the work on the display device so as to be distinguishable from each other. As shown in FIGS. 20 and 21, in the measurement mode, an image is acquired for a part of the work. The user may also want to know that the image is correctly acquired at the set magnification for each measurement point. Therefore, it is useful to display the low-magnification image and the high-magnification image in a distinguishable manner. For example, the controller 60 may make the border of the low-magnification image different from the border of the high-magnification image. For example, the border color of the low-magnification image and the border color of the high-magnification image may be different. The thickness of the border of the low-magnification image and the thickness of the border 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 broken line. It would be sufficient if such a visually distinguishable display object was adopted.

As described in connection with FIG. 22, the processor displays the entire image including the entire work on the display device in the measurement mode, accepts the designation of a part of the entire image from the user, and receives the part. A low-magnification image or a high-magnification image corresponding to the above-mentioned 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 smaller than the total area of the work. Therefore, it becomes difficult for the user to visually recognize the features reflected in the high-magnification image from the high-magnification image mapped to the entire image of the work. Therefore, when the user specifies a high-magnification image in the entire image, the processor may enlarge 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. Although the magnified display of the high-magnification image has been described here, similarly, the processor may execute the magnified display of the low-magnification image.

As described in relation to S604 and the like, the processor specifies the measurement points of the work to be imaged through the low-magnification optical system and the measurement points of the work to be imaged through the high-magnification optical system in the setting mode. Imaging setting information may be created by accepting the designation.

As described in connection with S602 and S603, the processor, in set mode, uses low magnification optics to generate multiple low magnification images to cover the entire workpiece, producing the plurality of low magnification images. By concatenating, a concatenated image (whole image) showing the entire work may be generated. As described in connection with S604 and S605, the processor may generate a high magnification image using a high magnification optical system at a location designated by the user in the connected image. In this way, since the high-magnification image is acquired only at the location designated by the user, the number of times the high-magnification image is captured is reduced even in the setting mode. That is, the waiting time of the user due to the imaging is reduced.

As described in connection with S607, in the setting mode, the processor captures the position information indicating the imaging position of the low-magnification image and the imaging of the high-magnification image based on the result of the pattern search, the reference imaging position information and the measurement location 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 is different for each work. This is because the work is manually placed by the user. Therefore, the imaging position of each measurement point is dynamically determined according to the position and posture of each work. The position and orientation of each work are specified by pattern search using a reference image. That is, the imaging position corresponding to the measurement location information is corrected according to the deviation amount of the position of each work and the deviation amount of the posture with respect to the reference image (reference imaging position), and the imaging position of each measurement location is dynamically determined. .. This eliminates the need for a jig for positioning the work, and allows the user to freely place the work.

As described in connection with FIG. 6, in the setting mode, when the processor acquires the target image of the pattern search, the transillumination unit is turned off and the epi-illumination unit is turned on to turn on the epi-illumination unit for the work. You may accept the setting of whether to generate an image. When the processor is set to generate an epi-illumination image in the measurement mode, the transmitted illumination unit irradiates the work with transmitted illumination light to generate a target image for pattern search, and the transmitted illumination unit is used. By turning off the light and turning on the epi-illumination unit, an epi-illumination image of the work is generated. When it is not set to generate an epi-illumination image, the processor generates a target image for pattern search by irradiating the work with transmitted illumination light by the transmitted illumination unit in the measurement mode. In the case where the image including the outer shape of the work is the reference image, the transmitted illumination light is advantageous for the pattern search. In the case where the image including the features inside the outer shape of the work is the reference image, the epi-illuminated light is advantageous for the 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 work using a low magnification image or a high magnification image in the setting mode. For example, different measurement settings may be saved by multiple setting 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 the setting data, the controller 60 may display a thumbnail image of each setting data on the display device 11. As shown in FIGS. 17 to 19, thumbnail images may be displayed in measurement mode.

In the measurement mode, the processor may perform the measurement of the workpiece using the edge extracted from the low magnification image and the edge 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 second edge extracted from the high magnification image are extracted. The distance to the second edge is measured. However, by making it possible to measure the work 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 the user.

As shown in FIG. 21, the processor (measurement unit 67) may display the measurement result together with the connected image acquired in the setting mode in the measurement mode. By diverting the connected image acquired in the setting mode in this way, 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 (measurement unit 67) replaces the 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 the connected image. At the same time, the measurement result of the measurement location may be displayed on the display device. The image of the measurement location is always acquired in the measurement mode. Therefore, the image of the measurement location may be displayed by being combined or superimposed on the connected image. That is, the display device is generated by superimposing the measurement result on the connected image acquired in the setting mode and displaying it, or by synthesizing the measurement result on the connected 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 and the manufacturing error of the measurement point. Therefore, it is desirable that the image of the measurement point is an image individually acquired from each work.

The processor (measurement unit 67) replaces the image area 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 together with the connected image on the display device. You may.

The processor (controller 60) may save the connected image, the reference image, the reference imaging position information, the measurement location information, and the imaging setting information in the setting file (setting data 71). Further, the processor may save a thumbnail image symbolizing the content of the measurement specified by the configuration file in the configuration file. The bird's-eye view cameras 17R and 17L function as a bird's-eye view camera that acquires a bird's-eye view image of the mounting table. The processor may save the bird's-eye view image as a thumbnail image in the setting file. Generally, the bird's-eye view image shows the entire work. Therefore, the user will be able to easily select a desired setting file from 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. As a result, the user can confirm the measurement point while confirming the entire work.

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

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 the low-magnification image or high-magnification image acquired to form a concatenated image in the setting mode. Less than the number of sheets. Therefore, the processing time required for imaging in the measurement mode is shortened.

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

When the pattern search is successful in the measurement mode, the processor (controller 60) may specify 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 the display device to adjust the position of the workpiece on the mounting table. As a result, the user will be able to easily reproduce the placement position of the work determined in the setting mode even in the measurement mode.

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

When the pattern search is completed in the measurement mode, the processor (controller 60) captures 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 specified.

The processor (controller 60) may store the position information of the imaging range (eg, search area 166) of the reference image designated by the user in the memory in the setting mode. As shown in FIGS. 15 and 16, in the measurement mode, the processor guides the placement of the work 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. Guidance information for this may be displayed on the display device. This will make it easier for the user to adjust the position of the work appropriately.

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

In the setting mode, the processor (controller 60) accepts the designation of the registration area 167, which is an area for acquiring the reference image, and the designation of the search area 166, which is the area for pattern-searching the reference image, for the connected image. May be good. 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 the bird's-eye view 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 view camera may have a first camera (example: bird's-eye view camera 17R) and a second camera (example: bird's-eye view camera 17L) having different imaging ranges. The live image and the bird's-eye view image may be images acquired by the first camera and / or the second camera.

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

As described with reference to FIG. 2, the correction member 19 is provided below the first surface (surface) of the light transmitting plate 13 and above the transmitted illumination unit, and is generated by a low-magnification image sensor. It functions as a correction member imaged by the image pickup 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 image sensor. The controller 60 (creating unit 68) generates a low-magnification image of the correction member by imaging the correction member with the low-magnification image sensor, and images the correction member with the high-magnification image sensor to obtain a high magnification of the correction member. It functions as a processor that generates an image and creates position correction information based on a low-magnification image of the correction member and a high-magnification image of the correction member. The storage device 70 functions as a memory for storing 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 determine the position of the low-magnification image of the work generated by the low-magnification image sensor and the work generated by the high-magnification image sensor. Corrects the relationship with the position of the high-magnification image. As a result, the accuracy of the position of the work measured by using the low-magnification image sensor and the high-magnification image sensor is improved.

The correction member 19 may be provided anywhere as long as it is below the second surface (back surface) of the light transmitting plate 13 and above the transmitted illumination unit. As shown in FIG. 26A and the like, the correction member 19 may be fixed to the second surface of the light transmitting plate 13.

The storage device 70 may store the default position correction information acquired when the image measuring device is manufactured in 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 according to the environment in which the image measuring device is installed.

The controller 60 turns on the transmission illumination unit, turns off the epi-illumination unit, and images the correction member with the low-magnification image sensor to generate a low-magnification image of the correction member 19, and the correction member is generated by the high-magnification image sensor. A high-magnification image of the correction member may be generated by imaging. In this way, the transmitted illumination light makes it easier to detect the mark M.

When the controller 60 is activated by supplying power to the image measuring device, the controller 60 may execute the creation of the position correction information 44. In this way, the position correction information may be incorporated into the activation sequence. The controller 60 may execute the creation process according to the user instruction 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 light transmitting plate 13 may be substantially equal to each other. As shown in FIG. 25 (A) and the like, the correction member 19 may be provided with a repeating pattern (eg, mark M).

The controller 60 and the image pickup control unit 82 may function as an adjustment unit (autofocus unit) for adjusting the focus of the image pickup unit. The correction member is arranged at a position where the focus of the image pickup unit does not match the repeating pattern when the focus of the image pickup unit is in focus on the work. As a result, when the work W is imaged, the mark M is less likely to be reflected. That is, the mark M is less likely to affect the measurement of the work W.

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

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

The invention is not limited to the above-described embodiment, and various modifications and changes can be made within the scope of the gist of the invention.

Claims (13)

A mounting table having a translucent plate on which a work is placed on the first surface of the translucent plate,
A transmissive illumination unit provided below the translucent plate and irradiating a work placed on the transmissive plate with transmitted illumination light.
An epi-illumination unit provided above the translucent plate and irradiating a work placed on the translucent plate with epi-illumination light.
The work via a low-magnification image pickup element that images the work 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. An image pickup unit having a high-magnification image pickup element that captures an image and generates a high-magnification image,
The position of the low-magnification image provided between the first surface of the light-transmitting plate and the transmission illumination unit and generated by the low-magnification image sensor, and the high-magnification generated by the high-magnification image sensor. A correction member imaged by the image sensor when creating position correction information for correcting the relationship with the position of an image, and
A low-magnification image of the correction member is generated by imaging the correction member with the low-magnification image sensor, and a high-magnification image of the correction member is generated by imaging the correction member with the high-magnification image sensor. A processor that creates the position correction information based on the low-magnification image of the correction member and the high-magnification image of the correction member.
It has a memory for storing position correction information created by the processor, and has
Using the position correction information stored in the memory, the processor uses the position of the low-magnification image for the work generated by the low-magnification image sensor and the work generated by the high-magnification image sensor. An image measuring device that corrects the relationship with the position of the high-magnification image. The image measuring device according to claim 1, wherein the correction member is provided below the second surface of the transmissive plate and above the transmitted illumination unit. The image measuring device according to claim 2, wherein the correction member is fixed to the second surface of the translucent plate. The memory stores default position correction information acquired when the image measuring device is manufactured in a factory.
The image measuring device according to any one of claims 1 to 3, wherein the processor updates the default position correction information with the created position correction information. The processor turns on the transmitted illumination unit, turns off the epi-illumination unit, and images the correction member with the low-magnification image sensor to generate a low-magnification image of the correction member, and obtains the high-magnification image pickup. The image measuring device 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. The image measuring device according to any one of claims 1 to 5, wherein the processor executes the creation of the position correction information when power is supplied to the image measuring device and is 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 light transmissive plate are substantially equal to each other. The image measuring device according to any one of claims 1 to 7, wherein the correction member is provided with a repeating pattern. Further having an adjusting unit for adjusting the focus of the imaging unit,
The image measuring apparatus according to claim 8, wherein the correction member is arranged at a position where the focus of the imaging unit does not match the repeating pattern when the image pickup unit is in focus on the work. The image measuring apparatus according to claim 8 or 9, wherein the repeating pattern is dots arranged in a grid pattern. The image measuring device according to claim 8 or 9, wherein the repeating pattern is a cross mark. The image measuring apparatus according to any one of claims 1 to 11, wherein the processor executes measurement of the work using at least one of the low-magnification image and the high-magnification image of the work. The correction member is a transparent film having a repeating pattern, and is
The image measuring device according to any one of claims 1 to 12, which is attached to the second surface of the translucent plate.