A calibration plate and its use

Abstract

The application provides a calibration plate and application thereof, the calibration plate comprises a plurality of L-shaped mark areas, each of the mark areas comprises a plurality of feature points, the feature points in the same mark area are different in size, and the feature points in different mark areas are different in size. The application provides different measurement tolerances by arranging a plurality of mark areas on the calibration plate, each of the mark areas comprises a plurality of feature points, the feature points in the same mark area are different in size, the feature points in different mark areas are different in size, different mark areas provide patterns of different precision, a unified standard can be formed, consistency and standardization of measurement precision inspection are ensured, data comparison of similar measurement objects is facilitated, a measurement system can reach corresponding measurement clarity levels, MSA analysis and processing are facilitated, measurement errors are reduced, measurement precision is improved, human intervention is reduced, and measurement reliability is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of camera calibration, in particular to a calibration board and application thereof. BACKGROUND

[0002] With the rapid development of the lithium ion battery industry, the application range of lithium ion batteries is becoming more and more extensive, and the requirements for the standards and reliability of lithium ion batteries are continuously improving. The various indicators and reliability of the lithium battery roll core are also becoming higher and higher. In order to meet market demand, lithium battery equipment is also constantly improving.

[0003] In the lithium ion battery industry, the visual system CCD is gradually applied in actual production to measure the real-time change of the width of the pole piece, so as to correct deviation in time, improve production rate and efficiency, and MSA is a measurement system analysis. Its definition of measuring instrument accuracy includes five meanings in theory, including bias, linearity, stability, repeatability and reproducibility. It is a method of using mathematical statistics and charts to analyze the resolution and error of the measurement system to evaluate whether the resolution and error of the measurement system are suitable for the measured parameters. Therefore, MSA operation is very important for testing the accuracy of measurement data of the measurement system such as CCD. When the CCD system is doing MSA, the size of the pole piece needs to be measured multiple times to obtain multiple sets of measurement data, and then the analysis result is obtained according to the measurement requirement of MSA. However, in the prior art, the analysis of the above-mentioned five accuracy is not realized synchronously by the same testing device and the same method, and the repeatability test accuracy which is easy to test is used instead of the accuracy definition, so that the judgment basis and standard of the measurement accuracy cannot be unified, and the measurement accuracy lacks confidence. SUMMARY

[0004] The problem solved by the present application is that the existing calibration board has the risk of deviating from the measured value.

[0005] To solve the above problems, the first aspect of the present application provides a calibration board, which comprises a plurality of L-shaped mark areas, each of which comprises a plurality of feature points, the feature points of the same mark area are different in size, and the feature points of different mark areas are different in size.

[0006] Further, the calibration board comprises a first side and a second side, the first side and the second side are arranged perpendicularly, each of the mark areas comprises a first mark area and a second mark area, the first mark area is arranged parallel to the first side, the second mark area is arranged parallel to the second side, and a positioning point is arranged at the intersection of the first side and the second side.

[0007] Further, the intersection points of the first mark area and the second mark area of all mark areas are collinear with the positioning point.

[0008] Further, the measurement tolerance of different marking areas is different, and the size variation of each feature point in the same marking area is determined according to the measurement tolerance of the marking area and the number of feature points in the marking area.

[0009] Further, the measurement tolerance of the marking area gradually decreases with the distance between the marking area and the positioning point.

[0010] Further, the first marking area and the second marking area each include at least ten feature points, and the interval between any two adjacent feature points is the same.

[0011] Further, the shape of the feature point is a square or a circle.

[0012] Further, the calibration plate is a white opaque calibration plate, and the color of the calibration plate and the color of the calibration point are complementary colors.

[0013] Further, the calibration plate includes a substrate and an electrostatic sticker arranged on the substrate, and the electrostatic sticker is in contact with the object to be calibrated.

[0014] The second aspect of the present application provides a method for using a calibration plate, including the following steps:

[0015] Providing an object to be calibrated, and attaching the object to be calibrated and the calibration plate together;

[0016] The CCD system collects images and measures the size of the feature points in different marking areas on the calibration plate;

[0017] The object to be calibrated and the calibration plate are repeatedly run multiple times, the CCD system calculates the misalignment value of the size of the feature points in the different marking areas on the calibration plate each time, and according to the measurement requirements of MSA, the analysis result is obtained.

[0018] The calibration plate provided by the application has the advantages that: by arranging a plurality of mark areas on the calibration plate, each mark area includes a plurality of feature points, the feature points in the same mark area are different in size, the feature points in different mark areas are different in size, different mark areas provide different measurement tolerances, the feature points in different mark areas provide patterns of different precision, a unified standard can be formed to ensure the consistency and standardization of measurement precision inspection, not only facilitating data comparison of similar measurement objects, but also facilitating the measurement system to reach corresponding measurement clarity levels, which is beneficial to subsequent MSA analysis and processing, reduces measurement errors, improves measurement precision, reduces human intervention, improves measurement reliability, and the feature points in the same mark area are different in size, and the feature points in different mark areas are also different in size, which is also beneficial to detecting the size of defects on the pole piece; in addition, by arranging each calibration area into an L shape, calibration can be performed from two directions of the horizontal direction and the vertical direction, so that size measurement in different directions can also form a unified standard, which is beneficial to further ensuring the consistency and standardization of measurement precision inspection, the L-shaped mark area can also detect the angle of the pole piece, the calibration plate can detect the pole piece from multiple aspects, has a wide application range and high practicability;

[0019] The application method of the calibration plate provided by the application does not require manual operation in other steps except for bonding the object to be calibrated and the calibration piece together, and can be automatically realized by a CCD system, cancels manual sampling and measurement of data, can ensure the consistency of the same method, the same measurement line point and the same time sampling, and enables the CCD system to complete measurement precision detection and evaluation of the same standard, realizes the reliability of detection data; in addition, automatic detection by the CCD system can retain picture and time data, enhances the objectivity of data, and improves the measurement efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 FIG. 1 is a structural schematic diagram of a calibration plate in an embodiment of the application;

[0021] Figure 2 FIG. 2 is a flowchart of an application of a calibration piece in an embodiment of the application.

[0022] Explanation of Reference Signs:

[0023] 100: mark area; 200: feature point; 300: first side; 400: second side; 500: positioning point. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and thoroughly below with reference to the drawings. In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "perpendicular", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship shown in the drawings, and are merely intended to facilitate the description of the present application and simplify the description, and thus cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus cannot be understood as a limitation on the present application.

[0025] In the description of the embodiments of the present application, the term "in some preferred embodiments" means that the specific features, structures, materials or characteristics described in combination with the embodiments or examples are included in at least one preferred embodiment or preferred example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0026] Due to the complicated precision inspection process and the influence of human error factors, in actual use, a test result that is easy to operate is often used instead of the precision index of the gauge, resulting in the risk of deviation of the measured value during normal use of the production line. For example, MSA defines the precision of the gauge in theory to include five meanings of bias, linearity, stability, repeatability and reproducibility. However, in the prior art, since the same inspection device and the same method cannot simultaneously complete the analysis of the above-mentioned five precision, the repeatability test precision index that is easy to test is used instead of the precision definition, so that the basis and standard for judging the precision of measurement cannot be unified, and the precision of measurement lacks confidence.

[0027] In addition, the prior art combines the use of standard gauge blocks and manual sampling measurement in the measurement process, which cannot guarantee the same sampling measurement method, cannot sample the same measurement line point, and the manual inspection method is inefficient and has poor operability.

[0028] Therefore, the embodiments of the present application provide a calibration plate which can ensure the consistency and standardization of the measurement precision inspection.

[0029] In order to further illustrate the present application, the present application will be further illustrated below with reference to specific embodiments.

[0030] In combination with Figure 1As shown, the first aspect of the embodiment provides a calibration plate, which is a planar calibration plate, and a plurality of L-shaped mark areas 100 are arranged inside the outer frame of the calibration plate, each mark area 100 includes a plurality of feature points 200, the feature points 200 in the same mark area 100 are different in size, and the feature points 200 in different mark areas 100 are different in size, for example: Figure 1 The outer frame of the calibration plate is arranged with three L-shaped mark areas 100, and each of the three L-shaped mark areas 100 includes a plurality of feature points 200, the feature points 200 in the same L-shaped mark area 100 are different in size, and the feature points 200 in different L-shaped mark areas 100 are different in size.

[0031] Among them, the size of the feature point 200 represents the accuracy of the feature point 200, and different L-shaped mark areas 100 represent different measurement accuracy areas.

[0032] The accuracy of the feature points provided by the existing calibration plate is relatively single, which is not conducive to obtaining the clarity level of the CCD system and subsequent MSA analysis, and is also easy to bring larger measurement error, affecting the measurement accuracy.

[0033] In the embodiment, by arranging the outer frame on the plane, different calibration plates can be separated when there are multiple calibration plates in the field of view, which facilitates to reduce the interference of background patterns on recognition; by arranging a plurality of mark areas on the calibration plate, each mark area includes a plurality of feature points, the feature points in the same mark area are different in size, and the feature points in different mark areas are different in size, different measurement tolerances are provided by different mark areas, and different accuracy patterns are provided by the feature points in different mark areas, which can form a unified standard to ensure the consistency and standardization of measurement accuracy inspection, not only facilitating data comparison of similar measurement objects, but also facilitating the measurement system to reach the corresponding measurement clarity level, which is conducive to subsequent MSA analysis and processing, reduces measurement error, improves measurement accuracy, reduces human intervention, improves measurement reliability, and the feature points in the same mark area of the calibration plate are different in size, and the feature points in different mark areas are also different in size, which is also conducive to detecting the size of defects on the pole piece; in addition, by arranging each calibration area into an L shape, calibration can be performed from two directions of horizontal and vertical directions, so that size measurement in different directions can also form a unified standard, which is conducive to further ensuring the consistency and standardization of measurement accuracy inspection, the L-shaped mark area can also detect the angle of the pole piece, and the calibration plate can detect the pole piece from multiple aspects, has a wide application range, and has strong practicality.

[0034] On the basis of the above-mentioned embodiments, the measurement tolerances of different marking areas 100 are different, specifically, the measurement tolerances of different marking areas 100 can be 1mm, 0.5mm, 0.3mm and 0.1mm, etc., and those skilled in the art can set the measurement tolerances of different marking areas 100 according to actual conditions, but need to ensure that the measurement tolerances of different marking areas 100 are different to provide patterns of different accuracies, thereby improving the accuracy of measurement. For example: Figure 1 The measurement tolerance of the L-shaped marking area 100 close to the edge of the outer frame is 1mm, the measurement tolerance of the L-shaped marking area 100 in the middle is 0.5mm, and the measurement tolerance of the L-shaped marking area 100 far from the edge of the outer frame is 0.3mm.

[0035] On the basis of the above-mentioned embodiments, the size of each feature point 200 in the same marking area 100 can be determined according to the measurement tolerance of the marking area 100 and the number of feature points 200 in the marking area 100, specifically, if the measurement tolerance of the L-shaped marking area 100 close to the edge of the outer frame is 1mm, and the L-shaped marking area 100 has N feature points 200 along the length direction and the width direction, then along the length direction or the width direction, the size of the feature point 200 changes by a ratio of 1 / N, for example: Figure 1 The measurement tolerance of the L-shaped marking area 100 close to the edge of the outer frame is 1mm, and the L-shaped marking area 100 has 1, 2, …, 10 feature points 200 along the length direction and A, B, …, J feature points 200 along the width direction, then the width of feature point 1 or A is 10.4mm, the width of feature point 2 or B is 9.5mm, the width of feature point 3 or C is 10.3mm, the width of feature point 4 or D is 9.6mm, the width of feature point 5 or E is 10.2mm, the width of feature point 6 or F is 9.7mm, the width of feature point 7 or G is 10.1mm, the width of feature point 8 or H is 9.8mm, the width of feature point 9 or I is 10mm, and the width of feature point 10 or J is 9.9mm. Thus, the size of each feature point 200 in the same marking area 100 is slightly different, which can ensure that the calibration plate provides enough measurement size, facilitate repeated measurement of the calibration plate, ensure the repeatability and reproducibility of the calibration plate, and is conducive to improving the accuracy and reliability of the measurement result; in addition, the size of each feature point 200 in the same marking area is different, so that the CCD system can simulate at least ten samples and obtain the size of at least ten samples by taking one picture, which greatly shortens the detection time and improves the detection efficiency.

[0036] It should be noted that in the present embodiment, the length direction refers to the x-axis direction in Figure 1 , and the width direction refers to the y-axis direction in Figure 1 .

[0037] On the basis of the above embodiment, the size of each feature point 200 in the same marking area 100 along the length direction is randomly changed, that is, the size of each feature point 200 in the same marking area 100 along the length direction is not increased or decreased along the length direction; the size of each feature point 200 in the same marking area 100 along the width direction is randomly changed, that is, the size of each feature point 200 in the same marking area 100 along the width direction is not increased or decreased along the width direction. Thus, inertia values are prevented from occurring during measurement, affecting the accuracy of the measurement results.

[0038] It should be noted that the size of the feature point 200 in different marking areas 100 is not further limited in the embodiment, and those skilled in the art can determine it according to the measurement system analysis, for example, the size of the feature point 200 can range from 0.01 um to 10 mm, Figure 1 There are three different marking areas 100 in the embodiment, and the feature points 200 in each marking area 100 are squares. The sizes of the feature points 200 in the three marking areas 100 are different, and the width of the largest feature point 200 in the three marking areas 100 is 10 mm, the width of the middle feature point 200 is 1 um, and the width of the smallest feature point 200 is 0.01 um. If the feature points 200 in each marking area 100 are circles, the diameter of the largest feature point 200 in the three marking areas 100 can be 10 mm, the diameter of the middle feature point 200 can be 1 um, and the diameter of the smallest feature point 200 can be 0.01 um.

[0039] In the embodiment, the number of L-shaped marking areas 100 arranged inside the outer frame of the calibration plate is not further limited, and those skilled in the art can arrange it according to the size and space of the calibration sheet, but at least three L-shaped marking areas 100 are arranged inside the outer frame of the calibration plate, thereby further improving the measurement accuracy.

[0040] In the embodiment, the outer frame of the calibration plate can be a black rectangular frame at the edge of the calibration plate, which forms a closed area to enclose all the feature points 200. The outer frame can quickly locate the calibration plate area during CCD detection, accelerate the recognition speed, improve the recognition efficiency, and reduce the interference of background patterns on recognition. In addition, when there are multiple calibration plates in the field of view, the outer frame can separate different calibration plates to ensure that the features of different calibration plates do not interfere with each other.

[0041] The outer frame of the calibration plate comprises a first side edge 300 and a second side edge 400, the first side edge 300 is arranged along the length direction of the calibration plate, the second side edge 400 is arranged along the width direction of the calibration plate, the first side edge 300 and the second side edge 400 are arranged perpendicularly, each marking area 100 comprises a first marking area and a second marking area, the first marking area is arranged parallel to the first side edge, and the second marking area is arranged parallel to the second side edge, that is, the first marking area and the second marking area are arranged perpendicularly. Therefore, it is convenient to calibrate from the length direction and the width direction, so that the size measurement in different directions can also form a unified standard, which is beneficial to further ensure the consistency and standardization of the measurement accuracy inspection, and different measurement accuracies can be achieved by translation, thereby improving the flexibility and convenience of the calibration plate.

[0042] In some optional embodiments, the angle between the first marking area and the second marking area of each marking area 100 is adjustable, so that the first marking area and the second marking area are in a non-perpendicular state, and the included angle therebetween can be an acute angle or an obtuse angle, that is, the first marking area of each marking area 100 can be inclined at a certain angle to form a certain included angle with the x-axis, and the second marking area can also be inclined at a certain angle to form a certain included angle with the y-axis, thereby enabling the marking area 100 to perform angle detection on the pole piece.

[0043] On the basis of the above-mentioned embodiments, a positioning point 500 is arranged at the intersection of the first side edge and the second side edge, and the positioning point 500 is in an L shape, so as to facilitate positioning and determine the positions of the feature points in the calibration plate.

[0044] On the basis of the above-mentioned embodiments, the intersection points of the first marking area and the second marking area of all the marking areas 100 are collinear with the positioning point 500, specifically, the intersection points of the first marking area and the second marking area of all the marking areas 100 are located on the diagonal line of the calibration plate, and the positioning point 500 is also located on the diagonal line of the calibration plate, thereby enabling direct positioning in different marking areas 100 and ensuring that different angles and accuracies are more convenient to identify, which is beneficial to further improve the measurement accuracy of different marking areas 100.

[0045] On the basis of the above-mentioned embodiments, the measurement tolerance of the marking area 100 gradually decreases with the distance of the marking area 100 from the positioning point 500, that is, the measurement tolerance of the marking area 100 closer to the positioning point 500 is larger, and the measurement tolerance of the marking area 100 farther from the positioning point 500 is smaller, for example, Figure 1The measurement tolerance of the L-shaped mark area 100 close to the edge of the frame is 1mm, the measurement tolerance of the L-shaped mark area 100 in the middle is 0.5mm, and the measurement tolerance of the L-shaped mark area 100 far from the edge of the frame is 0.3mm. Thus, the measurement tolerance of the mark area 100 close to the positioning point 500 is larger, which is easier to be identified and detected in time, and then the measurement system is moved to the mark area 100 with appropriate measurement tolerance, so that the measurement system reaches the most appropriate measurement clarity level, thereby the measurement system is easy to detect and can detect with high accuracy.

[0046] On the basis of the above-mentioned embodiments, the first mark area and the second mark area each include at least ten feature points 200, and the interval between any two adjacent feature points 200 is the same, that is, the first mark area includes at least ten feature points 200, the second mark area includes at least ten feature points 200, and the first mark area and the second mark area share a common vertex. Thus, the calibration plate can provide sufficient measurement size, which facilitates repeated measurement of the calibration plate and improves the accuracy and reliability of the measurement result.

[0047] It should be noted that the interval between any two adjacent feature points 200 is not further limited in the present embodiment, but the interval between any two adjacent feature points 200 is equal, which can be set by those skilled in the art according to actual conditions.

[0048] In the present embodiment, the shape of the feature point 200 can be circular or square, wherein the circular shape refers to a solid circle.

[0049] In the present embodiment, the feature point 200 can be printed on the calibration plate, and the printing process includes but is not limited to photolithography, laser engraving, light drawing, and laser printing.

[0050] In the present embodiment, the calibration plate is a white opaque calibration plate, and the feature point 200 and the calibration plate are complementary colors. The existing calibration plate usually adopts a transparent calibration plate, but the transparent calibration plate is prone to produce shadows during calibration, which affects the measurement accuracy. In the present embodiment, the white opaque calibration plate can avoid the formation of shadows due to reflection of the to-be-calibrated object, thereby affecting the measurement accuracy.

[0051] In the present embodiment, the calibration plate includes a base material and a white material coated on the base material. On the basis of the above-mentioned embodiments, the calibration plate includes a base material and an electrostatic sticker arranged on the base material. The electrostatic sticker can be a white PVC electrostatic film, and the electrostatic sticker is in contact with the to-be-calibrated object. Thus, by arranging the electrostatic sticker on the calibration plate, the calibration plate can be directly attached to the to-be-calibrated object, which facilitates quick use and makes the thickness of the calibration plate controllable. Compared with the transparent adhesive or masking paper in the prior art, the efficiency of attaching the calibration plate to the to-be-calibrated object is improved, and the thickness of the calibration plate is controllable, which can avoid affecting the measurement accuracy.

[0052] In the embodiment, the base material of the calibration plate can be paper, glass, ceramic, aluminum, and film, etc. In order to facilitate the application on the pole piece, the calibration plate is used on the winding machine, and the calibration plate adopts a thin and soft material. On the basis of the above embodiment, the base material of the calibration plate adopts a film or PET.

[0053] In the embodiment, the thickness of the calibration plate is not more than 0.3mm, thereby avoiding that the calibration plate is too thick to affect the measurement accuracy, and making the calibration plate more suitable for the CCD calibration of the lithium ion battery pole piece material.

[0054] Figure 2 The embodiment provides a flowchart of the application of the above calibration sheet test. In combination with the above-mentioned embodiment, the second aspect of the embodiment provides an application method of the calibration sheet, including the following steps: Figure 2

[0055] Step S210, providing a to-be-calibrated object, and sticking the to-be-calibrated object and the calibration sheet together.

[0056] Step S220, the CCD system performs image acquisition and size measurement on the feature points 200 in different mark areas 100 on the calibration plate.

[0057] Step S230, the to-be-calibrated object and the calibration plate are moved repeatedly, the CCD system calculates the misregistration value of the size of the feature points 200 in different mark areas 100 on the calibration plate in each measurement, and obtains the analysis result according to the measurement requirement of MSA.

[0058] Specifically, in step S210, the calibration plate is placed on the to-be-calibrated object. The to-be-calibrated object can be a pole piece, and the calibration plate can be pasted with the to-be-calibrated object through the electrostatic sticker arranged thereon. When the to-be-calibrated object moves, the calibration plate moves with the to-be-calibrated object.

[0059] In step S220, the to-be-calibrated object and the calibration plate are placed on the object table of the CCD, and then the to-be-calibrated object and the calibration plate are moved. At the same time, the CCD system is started, and the CCD system performs image information acquisition and measurement of the size information of each feature point 200 on more than 10 feature points of different mark areas 100 on the calibration plate. Wherein, the number of feature points 200 on the same mark area 100, the size and dimension of each feature point 200 are slightly different, and the measurement tolerance of different mark areas 100 is different. After obtaining the size information of each feature point 200, the precision grade of the feature point 200 can be obtained.

[0060] ​The to-be-calibrated object and the calibration plate can move along the length direction of the calibration plate or along the width direction of the calibration plate. In the embodiment, the size information of each feature point 200 along the length direction of the calibration plate can be obtained, the size information of each feature point 200 along the width direction of the calibration plate can be obtained, or both the size information of each feature point 200 along the length direction of the calibration plate and the size information of each feature point 200 along the width direction of the calibration plate can be obtained. For example, the position of the positioning point 500 of the calibration plate is obtained, the size and precision level of more than 10 different feature points 200 in the width direction of the calibration plate are obtained, and the size and precision level of more than 10 different feature points 200 in the length direction of the calibration plate are obtained.

[0061] In the embodiment, at least ten feature points 200 with the same interval are arranged on the same marking area 100 of the calibration plate along the length direction and the width direction of the calibration plate, so that the size of the polar plate in different directions can be measured. Whether the size of the polar plate in the length direction is measured or the size of the polar plate in the width direction is measured, only one calibration plate can be used, so that the size of the polar plate in different directions can form a unified standard, and the consistency and standardization of the measurement precision test can be further ensured.

[0062] In step S230, the to-be-calibrated object and the calibration plate are repeatedly moved, the CCD system calculates the misalignment value of the size data of the feature points 200 in the different marking areas 100 of the calibration plate in each measurement, and obtains the analysis result according to the measurement requirement of MSA. The measurement requirement of MSA can be GRR analysis, that is, the repeatability and reproducibility of the measurement data of the CCD system are analyzed. The CCD system measures multiple groups of data, and then analyzes and compares whether the error rate between the collected data and the standard data meets the requirement of GRR, so as to determine whether the CCD system is qualified.

[0063] In the embodiment, in addition to the calibration of the object to be calibrated and the calibration sheet together, other steps do not need manual operation, can be realized automatically through the CCD system, cancels the manual sampling measurement data, can guarantee the same method, the same measurement line point and the same time effect sampling consistency method, so that the CCD system can complete the same standard measurement accuracy detection and evaluation, realizes the reliability of the detection data; in addition, through the CCD system automatic realization detection can retain the picture and time data, enhances the objectivity of the data. The marking plate in the embodiment provides different precision patterns through the feature points 200 of different marking areas 100, can form a unified standard, guarantees the consistency and standardization of the measurement accuracy test, not only facilitates the data comparison of the same measurement object, but also facilitates the measurement system to reach the corresponding measurement clarity level, is conducive to the subsequent MSA analysis and processing, reduces the measurement error, improves the measurement accuracy, reduces the human intervention, improves the measurement reliability, and the size of each feature point 200 in the same marking area is different, then the CCD system can simulate at least ten samples and obtain the size of at least ten samples by taking a picture once, greatly shortens the detection time and improves the detection efficiency.

[0064] Although the present disclosure is disclosed as above, the protection scope of the present disclosure is not limited to this. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure, and these changes and modifications will fall within the protection scope of the present disclosure.

Claims

1. A calibration plate, characterized in that The calibration plate comprises a plurality of L-shaped mark areas, each of which comprises a plurality of feature points, the feature points in the same mark area are different in size, and the feature points in different mark areas are different in size. The calibration plate comprises a first side and a second side, the first side and the second side are arranged vertically, each of the mark areas comprises a first mark area and a second mark area, the first mark area is arranged parallel to the first side, the second mark area is arranged parallel to the second side, and a positioning point is arranged at the intersection of the first side and the second side. The measurement tolerances of different mark areas are different, and the size variation of each feature point in the same mark area is determined according to the measurement tolerance of the mark area and the number of feature points in the mark area.

2. The calibration board of claim 1, wherein, The intersection points of the first mark area and the second mark area of all mark areas are collinear with the positioning point.

3. The calibration board of claim 1, wherein, The measurement tolerances of the mark areas gradually decrease with the distance of the mark areas from the positioning point.

4. The calibration board of claim 1, wherein, The first mark area and the second mark area each comprise at least ten feature points, and the interval between any two adjacent feature points is the same.

5. The calibration board of claim 1, wherein, The shape of the feature point is a square or a circle.

6. The calibration board of claim 1, wherein, The calibration plate is a white opaque calibration plate, and the color of the calibration plate and the color of the feature point are complementary colors.

7. The calibration board of claim 1, wherein, The calibration plate comprises a substrate and an electrostatic sticker arranged on the substrate, and the electrostatic sticker is in contact with the object to be calibrated.

8. A method of using a calibration plate as claimed in claim 1, characterized in that, The method comprises the following steps: providing an object to be calibrated, and adhering the object to be calibrated to a calibration plate; a CCD system acquires images and measures the size of the feature points in different mark areas on the calibration plate; the object to be calibrated and the calibration plate are repeatedly run for multiple times, the CCD system calculates the misalignment value of the size of the feature points in the different mark areas on the calibration plate each time, and according to the measurement requirements of MSA, the analysis result is obtained.

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