Method for measuring offset, measuring device, and storage medium storing program non-transitorily

Abstract

The present application provides a method for measuring an offset, a measuring device, and a storage medium that stores a program non-transitorily, and can measure an offset of a setting angle of a camera that photographs a subject with respect to a reference direction of an axis, and correct the offset of the setting angle at low cost and high accuracy. The method for measuring an offset of a setting angle of a camera with respect to a reference direction of an axis using a measuring device is characterized by comprising: a photographing step of photographing a target object to which a reference index capable of determining a straight line with a known slope is attached multiple times at different fields of view; an image processing step of finding straight lines determined based on the reference index corresponding to each reference index in images photographed at different fields of view; and a calculation step of calculating a rotation angle that makes a distance between the multiple straight lines 0 as the offset of the setting angle.

Description

TECHNICAL FIELD

[0001] The present application relates to a method of measuring an offset, a measuring apparatus, and a storage medium that stores a program non-transitorily. BACKGROUND

[0002] In the past, a precision measuring apparatus of an aligner that performs posture alignment of a semiconductor wafer has been known. The precision measuring apparatus includes a photographing unit that photographs a pair of marks provided at a prescribed interval from a measurement surface of a precision measurement wafer of a reference index installed on a wafer stage in a detachable manner when the wafer is in a reference index and when the wafer is subjected to posture alignment by the aligner, and an image processing apparatus that measures the precision of the aligner based on image information obtained from each photographing (for example, refer to Patent Literature 1).

[0003] In addition, an electronic component mounting apparatus having a component mounting head, a camera that acquires an image of an electronic component, and an image processing section that performs distortion correction on the acquired image of the electronic component based on distortion correction data and recognizes the position of the electronic component based on the image on which the distortion correction has been performed has also been known. As for a method of correcting image distortion caused by camera posture and lens distortion that occurs in the camera for component position recognition of the electronic component mounting apparatus, an angle shift can be detected by photographing a distortion correction jig on which a dot chart is provided (for example, refer to Patent Literature 2). Further, a correction method of correcting a shift in the direction of the optical axis of a stereo camera including a first camera and a second camera fixed to a camera support body has also been known. In the correction method, a chart for correction can be photographed, and correction data can be created by comparing the coordinates of the output lattice points with ideal coordinates without a shift that are held in advance (for example, refer to Patent Literature 3).

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Publication No. 2003-318249

[0007] Patent Literature 2: Japanese Patent Application Publication No. 2013-239720

[0008] Patent Literature 3: Japanese Patent Application Publication No. 2019-090755 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] For example, when a camera is moved in parallel along an axis to take an image of a subject, or when a camera is fixed to an axis to take an image of a subject carried by a belt conveyor or the like, it is possible that the angle of the image is shifted due to a shift in the setting angle of the camera. In the above-described Patent Documents 1 to 3, it is disclosed that the shift in the angle of the image taken by a camera is corrected. In order to improve the accuracy of the correction, there is a method of mounting a camera with high accuracy with respect to an axis, but the introduction of this method results in an increase in cost. In addition, in the above-described Patent Documents 1 to 3, there is a method of detecting a shift in the setting angle of a camera in one field of view by taking an image of a subject once by the camera, for example, as a software-based correction, but the present situation is that high measurement accuracy cannot be expected in this detection method.

[0011] The present application was made in view of the above-described problems, and the ultimate object thereof is to provide a measurement method, a measurement device, and a storage medium that non-transitorily stores a program, capable of measuring a shift in the setting angle of a camera that takes an image of a subject with respect to a reference direction of an axis, and correcting the shift in the setting angle with low cost and high accuracy. Furthermore, in the following application examples and embodiments, the measurement method, the measurement device, and the storage medium that non-transitorily stores a program also indicate a measurement method, a measurement device, and a storage medium that non-transitorily stores a program of a shift in the setting angle of a camera with respect to a reference direction of an axis.

[0012] Means for solving the problem

[0013] The present disclosure for solving the above-described problem is a measurement method for measuring a shift in the setting angle of a camera provided to a support with respect to a prescribed reference direction of the support, the measurement method being characterized by using a target to which a reference index is attached, the reference index being capable of determining a straight line that is parallel to the reference direction or has a prescribed angle with respect to the reference direction, the measurement method having: a photographing step of photographing the target a plurality of times with different fields of view by moving the camera or the target along the reference direction; an image processing step of finding the straight line determined based on the reference index corresponding to each of the reference indexes in the images photographed with the different fields of view; and a calculation step of calculating a rotation angle that makes the distance between a plurality of the straight lines 0 as the shift in the setting angle.

[0014] In the photographing step, the target object to which the reference index is attached is photographed a plurality of times with different fields of view, and in the calculating step, the rotation angle is calculated as the shift of the setting angle with high precision. Therefore, the shift of the setting angle measured by the above-described measurement method is highly reliable, and if the shift of the setting angle can be accurately grasped, the shift of the setting angle can be corrected with high precision by manual or automatic means. In addition, the above-described measurement method is simple, and the shift of the setting angle can be corrected at low cost. Furthermore, the above-described prescribed angle refers to the angle of the target object with respect to the reference direction when the target object is disposed in a state of being non-parallel with respect to the reference direction. Whether the target object is disposed in parallel with respect to the reference direction or in a non-parallel state, the rotation angle can be calculated as the shift of the setting angle in the calculating step.

[0015] In addition, in the present disclosure, the measurement method can further include a display step of displaying data related to at least one of the reference index in the image photographed in the photographing step with the different fields of view, the straight line calculated in the image processing step, and the rotation angle calculated in the calculating step. Thus, it is possible to visually and numerically grasp the case where the shift of the setting angle occurs and the shift amount of the setting angle.

[0016] In addition, in the present disclosure, the measurement method can further include a communication step of transmitting data related to at least one of the reference index in the image photographed in the photographing step with the different fields of view, the straight line calculated in the image processing step, and the rotation angle calculated in the calculating step, and receiving information related to the shift amount of the setting angle based on the data. Thus, it is possible to transmit the case where the shift of the setting angle occurs and the shift amount of the setting angle to an external device, and it is also possible to receive feedback for improving the response to the shift of the setting angle from, for example, an expert.

[0017] In addition, in the present disclosure, the measurement method can further include a judgment step of judging whether a stain in the reference index exceeds a prescribed threshold value, and a notification step of notifying the position of the stain, the level of the stain, and a response corresponding to the level, in a case where the stain exceeds the prescribed threshold value. Since the stain in the reference index makes it difficult to accurately recognize the reference index in the image processing step, the accuracy of calculating the rotation angle can be reduced in the calculating step, and thus it is possible to accurately grasp information related to the stain and to suppress the possibility of reducing the accuracy of calculating the rotation angle.

[0018] Further, in the present disclosure, the measuring method can be characterized in that, in the judging step, the stain is judged based on a proportion of black pixels to white pixels of the reference index. Thus, the stain is judged based on the proportion of black pixels to white pixels, and therefore optical inspection is easily applied.

[0019] Further, in the present disclosure, the measuring method can be characterized in that, further comprising a second calculating step of calculating a difference between the set angle offset and a prescribed standard value, or periodically calculating the set angle offset, and a second notifying step of notifying a warning when the difference between the set angle offset and the prescribed standard value, or the set angle offset is a prescribed value or more. Thus, the set angle offset can be grasped promptly.

[0020] Further, in the present disclosure, the measuring method can be characterized in that, in the calculating step, the rotation angles corresponding to the plurality of cameras are calculated, and an average of all the rotation angles is calculated as the set angle offset. Thus, the set angle offset can be measured with higher reliability.

[0021] Further, in the present disclosure, the measuring method can be characterized in that the reference index is a pattern of a straight line shape arranged on the target. As the pattern, for example, a dot, a cross, or the like, and thus the range of variation is wide when the reference index is designed.

[0022] Further, in the present disclosure, the measuring method can be characterized in that the reference index is a straight line drawn on the target. Thus, the range of variation is wide when the reference index is designed. Further, the straight line is easily obtained in the image processing step.

[0023] Further, in the present disclosure, the measuring method can be characterized in that the reference index is a straight line projected on the target. For example, there is projection using laser or the like as a medium, and thus the reference index having an accurate size is easily projected on the target.

[0024] Further, in the present disclosure, the measuring method can be characterized in that the reference index is a component arranged in a straight line shape on the target, or a structure formed in a straight line shape on the target. As the component arranged in a straight line shape on the target, for example, there is an LED light emitting element, and thus the reference index having an accurate size is easily formed on the target.

[0025] Further, in the present disclosure, a computer-readable storage medium can be provided, which stores a program for causing a measuring device to execute each step of the above-described measuring method.

[0026] Further, the present disclosure can also include a measurement device that has a camera provided to a support body, for measuring an offset amount of a set angle with respect to a prescribed reference direction of the support body, the measurement device being characterized in that the measurement device uses a target object to which a reference index is attached, the reference index being capable of determining a straight line that is parallel to the reference direction or has a prescribed angle with respect to the reference direction, the measurement device having: an image processing section that, after capturing the target object multiple times with different fields of view by moving the camera or the target object along the reference direction, calculates a straight line determined based on the reference index corresponding to each of the reference indices in images captured with the different fields of view from the camera; and a calculation section that calculates a rotation angle that makes the distance between a plurality of the straight lines zero, as the offset amount of the set angle.

[0027] By capturing the target object to which the reference index is attached multiple times with different fields of view by the camera, the calculation section can calculate the rotation angle as the offset amount of the set angle with high precision. Therefore, the reliability of the offset amount of the set angle measured by the measurement device described above is high, and if the offset amount of the set angle can be accurately grasped, the offset of the set angle can be corrected with high precision by manual or automatic means. Further, the measurement device described above has a simple structure, and can correct the offset of the set angle at low cost. Furthermore, the rotation angle can be calculated as the offset amount of the set angle by the calculation section, regardless of whether the target object is disposed parallel to the reference direction or in a non-parallel state.

[0028] Further, in the present disclosure, the measurement device can be characterized by further having a display section that displays data related to at least one of each of the reference indices in the images captured with the different fields of view by the camera, the straight lines calculated by the image processing section, and the rotation angle calculated by the calculation section. By displaying this data by the display section, it is possible to grasp visually and numerically whether the offset of the set angle has occurred, and the offset amount of the set angle.

[0029] Further, in the present disclosure, the measurement device can be characterized by further having a communication section that transmits data related to at least one of each of the reference indices in the images captured with the different fields of view by the camera, the straight lines calculated by the image processing section, and the rotation angle calculated by the calculation section, and receives information related to the offset amount of the set angle based on the data. Thereby, it is possible to transmit whether the offset of the set angle has occurred, and the offset amount of the set angle, to an external device, and it is also possible to receive feedback for a countermeasure method for improving the offset of the set angle from, for example, an expert or the like.

[0030] Further, in the present disclosure, the measuring device can be characterized in that, in a case where the communication section transmits the data and receives information about the shift of the set angle, the display section displays that the shift of the set angle has been corrected. Thus, the effectiveness and safety of the measuring device described above can be ensured, and the accuracy of the measuring device described above can be high.

[0031] Further, in the present disclosure, the measuring device can be characterized in that it further includes a judgment section that judges whether or not a stain in the reference index exceeds a prescribed threshold value, and a notification section that, in a case where the stain exceeds the prescribed threshold value, notifies the position of the stain, the degree of the stain, and a countermeasure corresponding to the degree. Thus, information about a stain in the reference index can be accurately grasped, and the possibility that the accuracy of the calculated rotation angle decreases due to a stain can be suppressed.

[0032] Further, in the present disclosure, the measuring device can be characterized in that the judgment section judges the stain according to the proportion of black pixels with respect to white pixels of the reference index. Thus, the stain is judged according to the proportion of black pixels with respect to white pixels, and thus optical inspection is easily applied.

[0033] Further, in the present disclosure, the measuring device can be characterized in that it further includes a second calculation section that calculates the difference between the shift of the set angle and a prescribed standard value, or periodically calculates the shift of the set angle, and a second notification section that, in a case where the difference between the shift of the set angle and the prescribed standard value, or the shift of the set angle, is a prescribed value or more, notifies a warning. Thus, the shift of the set angle can be promptly grasped.

[0034] Further, in the present disclosure, the measuring device can be characterized in that the calculation section calculates the rotation angles corresponding to a plurality of the cameras respectively, and calculates the average of all the rotation angles as the shift of the set angle. Thus, the shift of the set angle can be measured with higher reliability.

[0035] Further, in the present disclosure, the measuring device can be characterized in that the reference index is a pattern that is linearly arranged and labeled on the target object. Thus, when the reference index is designed, the range of variation of the pattern becomes wide.

[0036] Further, in the present disclosure, the measuring device can be characterized in that the reference index is a straight line drawn on the target object. Thus, when the reference index is designed, the range of variation thereof becomes wide. Further, the straight line is easily obtained by the image processing section.

[0037] In addition, in the present disclosure, the measuring device can be characterized in that the reference index is a straight line projected onto the target object. Thus, it is easy to project a reference index having a correct size onto the target object.

[0038] In addition, in the present disclosure, the measuring device can be characterized in that the reference index is a member arranged in a straight line on the target object or a structure formed in a straight line on the target object. Thus, it is easy to form a reference index having an accurate size on the target object.

[0039] In addition, in the present disclosure, the measuring device can be characterized in that the shift of the set angle is automatically detected at the start. Thus, it is possible to periodically and automatically perform maintenance of the shift of the set angle.

[0040] In addition, in the present disclosure, a computer-readable storage medium can be provided, which stores a program for functioning as the above-described measuring device.

[0041] Note that the present disclosure can be understood as a measuring method including at least a part of the processing performed by the above-described units. In addition, the present disclosure can also be understood as a measuring device including at least a part of the above-described units. In addition, it can also be understood as a storage medium that non-transitorily stores a computer program for executing each step of the method.

[0042] Note that the means for solving the above-described problems can be used in combination with each other as much as possible.

[0043] Effects of Invention

[0044] According to the present disclosure, in a measuring method of a shift amount of a set angle of a camera with respect to a reference direction of an axis, a measuring device, and a storage medium that non-transitorily stores a program, it is possible to measure the shift amount, and correct the shift of the set angle with low cost and high accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0045] [ Figure 1 ] Figure 1 is a diagram showing an example of a hardware structure of a measuring device of an embodiment.

[0046] [ Figure 2 ] Figure 2 is a diagram for explaining a problem that can occur when a subject is photographed by a camera in a measuring device of an embodiment and a measuring method for solving the problem.

[0047] [ Figure 3 ] Figure 3 is a functional block diagram showing an example of a measuring device of an embodiment.

[0048] [Figure 4 Figure 4 (A) is a first explanatory diagram showing a method of measuring an offset amount of a set angle of a camera with respect to a movement axis using a measuring device of the embodiment. Figure 4 (B) is a second explanatory diagram showing a method of measuring an offset amount of a set angle of a camera with respect to a movement axis using a measuring device of the embodiment. Figure 4 (A) of the embodiment.

[0049] [ Figure 5 ] Figure 5 (B) of the embodiment. Figure 4 (A) of the embodiment.

[0050] [ Figure 6 ] Figure 6 is a diagram showing an example of contents of communication transmitted and received by a communication section in a measuring device of the embodiment.

[0051] [ Figure 7 ] Figure 7 is a flowchart showing a procedure of a measuring method using a measuring device of the embodiment.

[0052] Explanation of Reference Numerals

[0053] 1: Measuring device; 10: Camera; 11: Control device; 110: Image processing section; 111: Calculation section; 112: Judgment section; 113: Notification section; 114: Second calculation section; 115: Second notification section; 12: Data management server; 13: UI; 130: Display section; 131: Communication section; 2: Printed board; 21: Photography site; 3: Movement axis; 4: Jig; 41, 42: Dot diagram. DETAILED DESCRIPTION

[0054] [Application Example]

[0055] Hereinafter, a summary of an application example of the present disclosure will be described using a part of the drawings. The present disclosure can be applied to a measuring device 1 shown in FIG. 1. In addition, the present disclosure can be applied to a method shown in the explanatory diagrams of (A) to (B) of FIG. 2 by using the measuring device 1. Figure 1 Figure 4 Figure 5

[0056] Figure 1 is a diagram showing an example of a hardware structure of the measuring device 1 to which the present disclosure can be applied. The measuring device 1 in this application example is configured by connecting a camera 10, a control device 11, a data management server 12, and a UI (User Interface) 13 to each other via a communication line of wireless or wired.

[0057] ​​​​The control device 11 generates an image of the photographed object based on the photographed object photographed by the camera 10, processes the image using a storage medium that non-transitorily stores a check program registered in advance, and thereby determines whether the state of the photographed site in the photographed object is good or bad. The control device 11 includes, for example, a processor such as a CPU, a storage device such as a RAM, a ROM, an interface with an external device, and the like as a hardware structure. The control device 11 provides the functions described below by the CPU executing a storage medium that non-transitorily stores a program. Part or all of each of the above-described functions can also be implemented by a hardware circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). Figure 3 The details of each of these functional units are described in the functional block diagram of FIG. 6. Figure 3

[0058] In the present application example, a photographed site 21 on a printed board 2 is exemplified as an example of the photographed object. As the photographed site 21, for example, there are a wiring, a via, and the like of the printed board 2. In the present application example, the camera 10 is used to photograph the photographed site 21 on the printed board 2 conveyed in the direction of the arrow shown in FIG. 1 by a conveyer line (omitted from the drawing), but the printed board 2 can be fixed to photograph the photographed site 21. Figure 2 Figure 1

[0059] In addition, as the control performed by the control device 11 on the camera 10 and the illumination (omitted from the drawing) that illuminates the printed board 2, for example, there are a change in the F value of the optical system of the camera 10, a change in the brightness of the illumination, calibration of the camera 10 and the illumination, and the like.

[0060] In the data management server 12, various data are stored in addition to the storage medium that non-transitorily stores the above-described check program, the check content data that determines the check item and the check reference for each photographed site 21, and various information required for processing in the UI 13 is registered.

[0061] Figure 2 is a diagram for explaining a problem that can occur when the photographed object is photographed using the camera 10 in the measurement device 1 to which the present disclosure can be applied and a measurement method for solving the problem. In addition, Figure 2 ​​​This is a schematic diagram showing the method by which the camera 10 photographs the subject, viewed from above. The camera 10 is mounted on a generally rectangular plate (not shown) on the movable axis 3, allowing it to move along the length of the movable axis 3 (hereinafter referred to as the reference direction). However, when the camera 10 is mounted on the plate (hereinafter, including the plate, referred to as the movable axis 3), the reference axis of the image captured by the camera 10 is mostly not fixed parallel to the reference direction of the movable axis 3, resulting in various issues. Figure 2 The amount θ shown represents the offset of the camera 10 relative to the moving axis 3 at the set angle. If an offset in the set angle occurs, then in the field of view of the camera 10 ( Figure 2 The diagonal section shown also exhibits an offset, making the analysis of the obtained image difficult. To correct this offset θ, i.e., to bring θ close to the ideal value of 0, the following method is used in this application example. Figure 3 The measuring device 1, as shown in the functional block diagram, is used to measure the offset θ of the set angle. The specific method is as follows... Figure 4 (A) to Figure 5 The diagram is provided for illustration. Here, the movable axis 3 corresponds to the support body in this disclosure.

[0062] Figure 3 This is a functional block diagram illustrating an example of the measuring apparatus 1 disclosed herein. The control device 11 of the measuring apparatus 1 in this application example is configured to generally include an image processing unit 110 and a calculation unit 111, etc. During measurement... Figure 2 The angle shown below (hereinafter, will be...) Figure 2 When setting the offset θ of the angle shown (referred to as the setting angle), use the following... Figure 4 (A) to Figure 5 The fixture 4 shown in Figures 41 and 42 is supplemented with dots.

[0063] When determining the offset θ of the setting angle, firstly, point maps 41 and 42 are captured using camera 10. At this time, by moving camera 10 along the reference direction of the moving axis 3, or by moving the fixture 4 with attached point maps 41 and 42 while camera 10 is fixed, the fixture 4 is captured multiple times from different viewpoints. Image processing unit 110 acquires the images captured from camera 10 from different viewpoints and calculates the straight lines passing through point maps 41 and 42 corresponding to each point map 41 and 42 in the captured image 5. Furthermore, the slope of these straight lines can also be known. Calculation unit 111 calculates the rotation angle at which the distance between the calculated multiple straight lines is zero as the offset θ of the setting angle. (Details are available in...) Figure 4 (A) to Figure 5 The explanations are presented sequentially in the diagram.

[0064] Figure 4Figure (A) is a first explanatory diagram illustrating a method for measuring the offset θ of the setting angle using the measuring device 1 disclosed herein. As described above, firstly, the camera 10 is moved a distance L along the reference direction of the moving axis 3, and the fixture 4 with additional point diagrams 41 and 42 is photographed multiple times with different fields of view. In this application example, two photographs are taken with different fields of view, but the number of photographs is not limited to this. Furthermore, in Figure 4 In each of Images 1 and 2 in (A), the fixture 4, serving as the photographing object, is identical, and different dot plots 41 and 42 on the same fixture 4 are photographed from different viewpoints. The dimensions of dot plots 41 and 42 are predetermined, and in each of Images 1 and 2, a set of points arranged along the length direction (reference direction) of the fixture 4 constitutes dot plots 41 and 42. Furthermore, Images 1 and 2 may include other content as long as they contain dot plots 41 and 42 respectively. In Images 1 and 2, dot plots 41 and 42 are arranged in a straight line. Additionally, when setting the fixture 4, its length direction may be parallel to or not parallel to the reference direction of the moving axis 3. In this disclosure, the defined angle is the angle of the length direction of the fixture 4 relative to the reference direction of the moving axis 3 when the fixture 4 is set in a state where its length direction is not parallel to the reference direction of the moving axis 3. Here, the fixture 4 corresponds to the target object in this disclosure. Furthermore, dot plots 41 and 42 correspond to reference indices in this disclosure.

[0065] Figure 4 (B) means Figure 4 The second explanatory figure following (A). The image processing unit 110 regards the reference direction of the movement axis 3 as the x-axis, and uses two arrows along the short side directions of each of the images 1 and 2 ( Figure 4 Image 1 and Image 2 are rotated such that the two arrows shown in (A) are perpendicular to the x-axis, i.e., treated as the y-axis. After rotation, the straight lines (y = ax + b1, y = ax + b2) passing through points 41 and 42 are determined. These two lines have equal slopes and are parallel to each other, therefore they are separated by a distance p in the y-axis direction at any point. The equations for the two lines are derived based on the value of the distance L.

[0066] Figure 5 It means Figure 4 The third explanatory figure following (B). Since the two lines are parallel to each other, if each line is rotated in opposite directions by the same angle, the two lines will be aligned. The rotation angle φ at which they are aligned is geometrically equivalent to the offset θ of the set angle. That is, the calculation unit 111 rotates image 1 and image 2 in opposite directions with the distance p becoming 0, and calculates the rotation angle φ at this time as the offset θ of the set angle.

[0067] As described above, by using Figure 3The function of the measuring device 1 shown in the functional block diagram is to perform the following functions: Figure 4 (A) to Figure 5 The method illustrated in the diagram enables the low-cost and high-precision measurement of the offset θ of the setting angle. Furthermore, in this application example, an example is described where the jig 4 is set with its length direction parallel to the reference direction of the moving axis 3. In contrast, when the jig 4 is set with its length direction not parallel to the reference direction of the moving axis 3, the slope 'a' in the mathematical expressions (y = ax + b1, y = ax + b2) of the two lines changes. However, even in this case, the slopes of the two lines remain equal and they are parallel, and the offset θ of the setting angle can be calculated in the same manner as when the jig 4 is set with its length direction parallel to the reference direction of the moving axis 3.

[0068] [Example]

[0069] Hereinafter, the measurement method, measurement apparatus 1, and storage medium for non-transitory program storage of embodiments of the present disclosure will be described in more detail with the help of the accompanying drawings (including those temporarily described in the above application examples). Furthermore, the measurement method, measurement apparatus 1, and storage medium for non-transitory program storage of embodiments of the present disclosure are not limited to the following structures.

[0070] <Functional Structure>

[0071] Here, return Figure 3 The measuring apparatus 1 of this embodiment has the same structure as the measuring apparatus 1 described in the application examples; therefore, detailed descriptions of the contents already described in the application examples are omitted. Furthermore, in this specification, the same reference numerals are used to describe the same constituent elements.

[0072] In this embodiment, the measuring device 1's UI 13 is configured to generally include a display unit 130 and a communication unit 131, etc. The display unit 130 is, for example, a monitor or display screen, capable of displaying images captured by the camera 10 (…). Figure 4 The data related to the two straight lines calculated by the image processing unit 110 and the rotation angle φ calculated by the calculation unit 111, as shown in (A) in Images 1 and 2, are displayed visually. The display unit 130 is capable of displaying... Figure 4 (A) to Figure 5 The content is as shown in the illustration, but it is not necessary to show all its functions. For example, if it is Figure 4 As shown in (B), the display unit 130 only needs to display image 1 and image 2, and may not need to display the two straight lines. Furthermore, since only the rotation angle φ needs to be known, the display unit 130 may only display... Figure 5 The content shown.

[0073] The communication unit 131 can automatically send data related to the image captured by the camera 10, the two straight lines calculated by the image processing unit 110, and the rotation angle φ calculated by the calculation unit 111 to a pre-set or manually input transmission destination. Additionally, it can receive information related to the offset θ of the set angle based on the transmitted data from the transmission destination. Specific examples are as follows: Figure 6 As shown.

[0074] Alternatively, UI 13 may also include an input section (not shown) for inputting information to the control device 11, such as a keyboard or mouse. Furthermore, the control device 11 may also be configured to include UI 13.

[0075] Alternatively, the control device 11 may also be configured to include a judgment unit 112 and a notification unit 113. The image 1 and image 2 acquired by the image processing unit 110... Figure 4 In images 1 and 2 shown in (B), for example, when stains such as foreign objects are attached to dots 41 and 42, it is difficult to accurately identify dots 41 and 42, and the accuracy of the calculation unit 111 in calculating the rotation angle φ may be reduced.

[0076] The judgment unit 112 determines whether stains in dot patterns 41 and 42 in images 1 and 2 acquired by the image processing unit 110 exceed a predetermined threshold. A stain determination criterion is, for example, the ratio of black pixels to white pixels in dot patterns 41 and 42. If this ratio exceeds the predetermined threshold, the judgment unit 112 determines that stains are present in dot patterns 41 and 42. The notification unit 113 has an alarm function, such as a siren, and notifies, for example, the location of the stain, the stain level, and the corresponding response method when stains in dot patterns 41 and 42 exceed the predetermined threshold. Alternatively, the notification from the notification unit 113 can be displayed on the display unit 130 or sent to an external device by the communication unit 131.

[0077] Alternatively, the control device 11 may also include a second calculation unit 114 and a second notification unit 115. The second calculation unit 114 calculates the difference between the offset θ of the setting angle and a predetermined standard value, or periodically calculates the offset θ of the setting angle. In this case, the second calculation unit 114 may perform the calculation based on data obtained from the image processing unit 110, or based on past data obtained from the image processing unit 110 stored in the data management server 12, or based on data directly obtained from the camera 10. The second notification unit 115 issues a warning when the offset θ of the setting angle is greater than or equal to a predetermined standard value, or when the offset θ of the setting angle is greater than or equal to a predetermined certain value. For example, a warning may be issued by outputting an error message such as "Camera setting angle offset standard" or "Camera setting angle change offset standard value". Furthermore, when the offset θ of the setting angle is less than or equal to a predetermined standard value, a notification may be issued indicating that there is no problem with the offset of the setting angle. Alternatively, the display unit 130 may display the content of the notification from the second notification unit 115, or the communication unit 131 may send it to an external device.

[0078] Furthermore, when the measuring device 1 is configured to include multiple cameras 10, the calculation unit 111 can also calculate the rotation angle φ corresponding to each of the multiple cameras 10, and calculate the average value of all rotation angles φ as the offset θ of the setting angle. In addition, the measuring device 1 may also have the function of automatically detecting the offset of the setting angle θ when it is started.

[0079] <Determination Method>

[0080] Here, return to Figure 4 (A) to Figure 5 The following explanation is provided. When measuring the offset θ of the setting angle, a fixture 4 is used, comprising multiple points arranged in a straight line, including dot diagrams 41 and 42. However, the type of fixture 4 is not limited to this. For example, the graphics attached to the fixture 4 are not limited to dots; they can also be crosses, quadrilaterals, etc. Alternatively, instead of dot diagrams 41 and 42, straight lines drawn with high precision on the fixture 4, such as square diagrams, can be used. Furthermore, components such as straight lines projected onto the fixture 4 via a medium such as a laser, or LED light-emitting elements arranged in a straight line on the fixture 4, can also be used. Alternatively, these indicators can be formed directly on the measuring device 1 instead of on the fixture 4. Furthermore, as indicators, straight-line structures formed on the measuring device 1 can also be used. Examples of such structures could be tracks constituting the moving shaft 3.

[0081] Figure 6is a diagram showing an example of contents of communication transmitted and received by the communication section 131 in the measurement device 1 of the embodiment. As an outline, the communication section 131 transmits data to an expert (a designer, a manufacturer, a manager, etc. of the measurement device 1) related to the measurement device 1, the expert performs measurement, judgment, etc. based on the data, and the communication section 131 receives information related to the offset angle θ of the setting angle based on the data.

[0082] As the data transmitted by the communication section 131 to the expert, for example, as described above, in addition to the images of the point graphs 41, 42 photographed by the camera 10, the two straight lines (may be only the formula of each straight line) calculated by the image processing section 110, and the rotation angle φ calculated by the calculation section 111, there are data related to the inspection performance of the measurement device 1, or an appearance photograph of the measurement device 1, a photograph of the jig 4, etc. For example, if the data transmitted is the images of the point graphs 41, 42 and the two straight lines, the expert can also calculate the rotation angle φ based on the data, and feedback the rotation angle φ as a result of the operation. In the case where the data transmitted is the rotation angle φ, assuming that the rotation angle φ is a value close to 0, the expert can judge that there is no problem in the setting of the camera 10 with respect to the movement axis 3, and otherwise, can prompt a method of manually correcting the offset of the setting angle as a method of coping with an error. If the data transmitted is the appearance photograph of the measurement device 1, the expert can confirm the deterioration with age of the measurement device 1, and prompt a maintenance countermeasure, etc. as a method of coping with an error. If the data transmitted is the photograph of the jig 4, it is possible to visually confirm the stains of the point graphs 41, 42, and prompt the cleaning of the jig 4.

[0083] In addition, in the case where the communication section 131 transmits the above-described data to the expert, and receives information related to the offset angle θ of the setting angle based on the above-described data from the expert, it is also possible to receive a correction certificate and a correction certificate expiration date together as proof that the offset of the setting angle has been corrected. At this time, it is possible to display the correction certificate and the correction certificate expiration date on the display section 130, and the correction certificate and the correction certificate expiration date can also be in a manner that can be updated. Further, in the case where the correction certificate expiration date is close or in the case where the correction certificate expiration date has passed, it is also possible to display this on the display section 130.

[0084] <Flowchart>

[0085] Figure 7is a flowchart showing a procedure of a measurement method using the measurement apparatus 1 of the embodiment. In this flowchart, first, the jig 4 is photographed twice with different fields of view by moving the camera 10 along the reference direction of the movement axis 3 or moving the jig 4 to which the dot patterns 41, 42 are attached in a state where the camera 10 is fixed (step S101). At this time, the photographing is performed in a manner that the dot patterns 41, 42 are included in each image. In addition, the number of times of photographing can be more than two. Here, the step S101 corresponds to the photographing step in the present disclosure and the (A) of the (B) in the present embodiment. Figure 4 Next, the image processing section 110 obtains the two straight lines passing through the dot patterns 41, 42 from the images photographed with different fields of view (step S102). The two straight lines are parallel to each other and depart from a fixed distance in a prescribed direction at an arbitrary position. Here, the step S102 corresponds to the image processing step in the present disclosure and the (B) in the present embodiment. Figure 4 Next, the calculation section 111 calculates the rotation angle φ at which the images photographed with different fields of view are rotated in opposite directions so that the fixed distance between the two straight lines becomes 0, i.e., the two straight lines coincide with each other, as the offset θ of the setting angle (step S103). Here, the step S103 corresponds to the calculation step in the present disclosure and the (C) in the present embodiment. Figure 5

[0086] In addition, the display section 130 can visually display the data related to the images photographed with different fields of view in the step S101, the two straight lines obtained in the step S102, and the rotation angle φ calculated in the step S103 (step S104). Here, the step S104 corresponds to the display step in the present disclosure. The communication section 131 can automatically transmit the data related to the images photographed with different fields of view in the step S101, the two straight lines obtained in the step S102, and the rotation angle φ calculated in the step S103 to the transmission destination registered in advance or to the transmission destination input manually. In addition, information related to the offset θ of the setting angle based on the transmitted data can be received from the transmission destination (step S105). Here, the step S105 corresponds to the communication step in the present disclosure and the (D) in the present embodiment. Figure 6

[0087] ​​Further, the judging section 112 judges whether or not the stains in the dot charts 41, 42 exceed a prescribed threshold in the image acquired in step S102 (step S106). In the case where the stains exceed the prescribed threshold (step S106: YES), the judging section 112 judges that the stains are attached to the dot charts 41, 42. In this case, the notifying section 113 notifies the position of the stains, the degree of the stains, and the countermeasure corresponding to the degree (step S107). Here, step S106 corresponds to the judging step in the present disclosure, and step S107 corresponds to the notifying step in the present disclosure. In the case where the stains do not exceed the prescribed threshold (step S106: NO), the notifying section 113 does not function.

[0088] Further, the 2nd calculating section 114 calculates the difference between the shift amount θ of the setting angle and a prescribed standard value, or periodically calculates the shift amount θ of the setting angle (step S108). At this time, the 2nd calculating section 114 can perform the calculation on the basis of the data acquired in step S102, or can perform the calculation on the basis of the data acquired in step S102 in the past stored in the data management server 12, or can perform the calculation on the basis of the data directly acquired in step S101. Here, step S108 corresponds to the 2nd calculating step in the present disclosure. In step S108, the 2nd notifying section 115 notifies a warning in the case where the difference between the shift amount θ of the setting angle and the prescribed standard value, or the shift amount θ of the setting angle is equal to or more than a prescribed certain value (step S109). Here, step S109 corresponds to the 2nd notifying step in the present disclosure. Further, in the case where the difference between the shift amount θ of the setting angle and the prescribed standard value, or the shift amount θ of the setting angle is less than the prescribed certain value, it is also possible to notify the meaning that there is no problem in the shift of the setting angle.

[0089] <Supplementary Note 1>

[0090] A measurement method for measuring a shift amount of a setting angle of a camera (10) provided to a support (3) with respect to a prescribed reference direction of the support, characterized by having: a photographing step (step S101) of photographing a target object (4) to which a reference index (41, 42) capable of determining a straight line parallel to or having a prescribed angle with respect to the reference direction is attached, a plurality of times with different fields of view by moving the camera or the target object along the reference direction; an image processing step (step S102) of finding the straight line determined on the basis of the reference index corresponding to each of the reference indices in the images photographed in the different fields of view; and a calculating step (step S103) of calculating a rotation angle making the distance between a plurality of the straight lines 0 as the shift amount of the setting angle.

[0091] <Supplementary Note 2>

[0092] A measuring device (1) provided with a camera (10) disposed on a support body (3) for measuring an offset of a set angle with respect to a prescribed reference direction of the support body, characterized in that a target object (4) to which reference indicators (41, 42) capable of determining a straight line parallel to or having a prescribed angle with respect to the reference direction are attached is used, the measuring device being provided with: an image processing section (110) which, after the target object is photographed a plurality of times with different fields of view by moving the camera or the target object along the reference direction, calculates a straight line determined based on the reference indicators corresponding to each of the reference indicators in images taken with the different fields of view taken from the camera; and a calculation section (111) which calculates a rotation angle making the distance between a plurality of the straight lines zero as the offset of the set angle.

Claims

1. A measurement method for measuring an amount of deviation of a set angle of a camera provided to a support body with respect to a prescribed reference direction of the support body, characterized by using a target object to which a reference index is attached, the reference index being capable of determining a straight line parallel to or having a prescribed angle with respect to the reference direction, the measurement method having: a photographing step of photographing the target object a plurality of times with different fields of view by moving the camera or the target object along the reference direction. an image processing step of obtaining the straight line determined based on the reference index corresponding to each of the reference indices in the images captured with the different fields of view; and a calculation step of calculating a rotation angle that makes the distance between the plurality of straight lines zero as the offset of the set angle.

2. A measuring device that has a camera provided to a support body, for measuring an offset of a set angle with respect to a prescribed reference direction of the support body, the measuring device being characterized by using a target object to which a reference index is attached, the reference index being capable of determining a straight line that is parallel to the reference direction or has a prescribed angle with respect to the reference direction, the measuring device having: an image processing section that, after capturing the target object a plurality of times with different fields of view by moving the camera or the target object along the reference direction, obtains a straight line determined based on the reference index corresponding to each of the reference indices in the images captured with the different fields of view from the camera; and a calculation section that calculates a rotation angle that makes the distance between the plurality of straight lines zero as the offset of the set angle.

3. The assay device of claim 2, wherein, The measuring device further has a display section that displays data related to at least one of each of the reference indices in the images captured with the different fields of view by the camera, the straight line obtained by the image processing section, and the rotation angle calculated by the calculation section.

4. The assay device of claim 2, wherein The measuring device further has a communication section that transmits data related to at least one of each of the reference indices in the images captured with the different fields of view by the camera, the straight line obtained by the image processing section, and the rotation angle calculated by the calculation section, and receives information related to the offset of the set angle based on the data.

5. The assay device of claim 3, wherein The measuring device further has a communication section that transmits data related to at least one of each of the reference indices in the images captured with the different fields of view by the camera, the straight line obtained by the image processing section, and the rotation angle calculated by the calculation section, and receives information related to the offset of the set angle based on the data, and the display section displays that the offset of the set angle has been corrected in a case where the communication section transmits the data and receives the information related to the offset of the set angle.

6. The assay device of claim 2, wherein The measuring device further has a second calculation section that calculates the difference between the offset of the set angle and a prescribed standard value, or periodically calculates the offset of the set angle, and a second notification section that notifies of a warning in a case where the difference between the offset of the set angle and the prescribed standard value, or the offset of the set angle, is a prescribed value or more.

7. The assay device of claim 2, wherein The calculation section calculates the rotation angle corresponding to each of the plurality of cameras, and calculates the average of all of the rotation angles as the offset of the set angle.

8. The assay device of claim 2, wherein, The reference index is a figure that is linearly arranged on the target object.

9. The assay device of claim 2, wherein, The reference index is a straight line drawn on the target object.

10. The assay device of claim 2, wherein The reference index is a component arranged in a straight line on the target object or a straight line-shaped structure formed on the target object.

11. The assay device of claim 2, wherein The shift of the set angle is automatically detected at the start.

12. A computer readable storage medium, characterized in that, The computer-readable storage medium stores a program for causing a computer to function as the measurement device according to any one of claims 2 to 11.

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