JP5545486B2 - Method and apparatus for measuring shape of coating pattern applied to sheet - Google Patents

Description

  The present invention relates to a method and an apparatus for measuring the shape of a pattern formed on, for example, a sheet-like substrate by coating or printing.

  For example, in a manufacturing process of a capacitor electrode or a battery electrode, a material (coating material) for applying a specific electrical property (coating material) to a sheet base material (hereinafter referred to as a sheet) is used. In that case, the coated material may be applied to the entire surface of the sheet. However, if the coated material is expensive or if there should be no coated material on the end surface of the sheet, apply the coating only to a specific part of the sheet. Do.

Such coating is called partial coating, block coating, pattern coating, or the like.
At that time, it is necessary to measure and manage the dimensions (width and length) of the coated part, and to measure the deviation of the front and back dimensions (width and length) when coating on both sides of the sheet.

  FIG. 7 shows an example of a conventional coating pattern measuring apparatus, and is a conceptual diagram when measuring using a camera. In FIG. 7, the sheet 1 is supported by a conveyance roller (not shown) and conveyed on the coating line at a constant speed. A plurality of cameras 31 (two in the figure) with the lens 30 attached are installed on the coating line and the coating dimensions are measured.

  When measuring the sheet 1, since the sheet moves at a constant speed, the camera 31 does not need to have two-dimensional information, so the image sensor is a line in which the sensor is arranged on a line perpendicular to the moving direction of the sheet A sensor camera is often used. Of course, it is also possible to use an area sensor camera having two-dimensional information for the image sensor. 32 indicates a coating portion, and 33 indicates a target portion.

In the case of such a coating dimension measuring system, the following performance is required.
1) Effects of path line fluctuations Ideally, sheet 1 is transported at the same position on the transport line. At this time, the position at which the sheet is conveyed is referred to as a pass line. However, depending on the location of the coating line, the sheet does not completely pass through the same location and may fluctuate vertically and horizontally. For example, in a place where there is no support between the transport rollers, the sheet 1 may vibrate up and down (pass line fluctuation). It is necessary to prevent the position variation from affecting the measurement of the coating dimension.

2) Flexible response to coating patterns Figure 7 shows the case where there is one coating pattern for the width of sheet 1 (single strip coating), but multiple coating patterns are formed in the width direction. There is a case. For example, when two patterns are formed in the sheet width direction (two-line coating), three cameras for imaging are required.

Furthermore, in order to cope with coating patterns such as strips 3 and 4, it is desirable that images can be taken over the entire sheet width.
3) Miniaturization The size of the coating line directly affects production costs, so miniaturization is desired as much as possible.

JP2002-42789 JP 2004-148534 A

  In the case of sheet width measurement using the camera 31 shown in the conventional example of FIG. 7, when a general lens 30 is used, when there is a vertical fluctuation (change in the optical axis direction) of the coating line, on the image sensor of the camera 31 There is a problem that the size of the image of the sheet changes.

  FIG. 8 (a) shows this state. In the general lens 30, the chief ray passes through the center of the lens, so that the image of the object A to be measured is formed on B as shown in the figure. When the object to be measured comes close to the lens and reaches the position A ′, the principal ray also passes through the center of the lens, so that the image A ′ is formed on B ′.

  In the drawing, for the sake of explanation, the positions of B and B 'are changed and drawn. However, both B and B' are on the image sensor and the positions are not changed. As can be seen in the figure, B 'is an image larger than B. That is, when the sheet to be measured is moved from A to A ′ due to a change in the optical axis direction, the size of the image changes, and the dimensions cannot be measured accurately.

Even in such a lens, the influence of fluctuation in the optical axis direction can be reduced by reducing the viewing angle of the lens.
FIG. 8B shows a state of image formation when the viewing angle of the lens 30 is reduced.
As shown in the figure, the image of the object A to be measured is formed on B. When the object to be measured approaches the lens 30 and comes to the position A ′, the principal ray passes through the center of the lens, so that the image A ′ is formed on B ′.

  In FIG. 8 (a, b), the positions of B and B ′ are drawn for the sake of explanation, but both B and B ′ are on the image sensor and the positions are not changed. As can be seen in the figure, B 'is an image larger than B, but the rate of change is smaller than in the case of FIG. The size of the image slightly changes as the measured sheet moves from A to A ', but the effect is smaller than when the viewing angle is large, so that the dimensional error can be reduced.

  However, if the viewing angle is small, the area that can be measured by one camera is small, so the number of cameras must be increased in order to measure the same size measurement object. If the number of cameras is increased, the number of computers for image input must be increased. However, since the cost of the entire apparatus is increased, conventionally, a method has been adopted in which images from a plurality of cameras are switched and sequentially captured.

  FIG. 9 is an explanatory diagram of a configuration showing a conventional example using four cameras 6 to 9. The objects to be measured are patterns 2 to 5 coated on the sheet 1. This is imaged by the cameras 6 to 9, but the input is switched at least in frame units of the video signal by the switch 10 for switching the video signal, and is taken into the computer 11 equipped with the image input board. At that time, since the sheet 1 is conveyed in the forward direction from the back of the paper surface, the imaging ranges by the cameras 6 to 9 are rectangles that are shifted in the conveying direction indicated by dotted lines 12 to 15, respectively.

  Originally, the width of the coating patterns 2 to 5 is to be measured at the same position with respect to the transport direction. That is, in the case of the coating pattern 2, we want to know the distance between the points 16 and 17. This is because it is desired to reduce the measurement error due to the influence of meandering in the width direction when the sheet 1 is conveyed. In the conventional example shown in FIG. 9, since the imaging ranges of the respective cameras are deviated, the points 16 and 17 are not included in the imaging range, so that there is a problem in that values at the same position cannot be obtained. There is a similar problem with respect to the distance in the transport direction.

  Accordingly, an object of the present invention is to realize the simultaneous measurement in the width direction and the conveyance direction in a measuring apparatus that measures the width and length of the coating pattern using a large number of cameras, and also affects the influence of the distance variation in the optical axis direction. An object of the present invention is to provide a coating pattern measuring method and apparatus that can be eliminated.

The present invention has been made to solve the above problems, and in the method for measuring the shape of the coating pattern applied to the sheet according to claim 1,
1) A step of arranging a plurality of cameras in a photographing direction of a horizontal line perpendicular to the sheet conveying direction, and photographing the sheet with the plurality of cameras,
2) including a step of synchronizing at least one of a horizontal scanning signal and a vertical scanning signal of the captured video with the horizontal scanning and sequentially switching the horizontal scanning signals of the plurality of cameras and taking them into the image processing means.

In claim 2, in the method for measuring the shape of the coating pattern applied to the sheet according to claim 1,
The shooting timing is simultaneous.
In claim 3, in the method for measuring the shape of the coating pattern applied to the sheet according to claim 1,
And a step of synthesizing at least one of a horizontal scanning signal and a vertical scanning signal of the captured image.

In claim 4, in the shape measuring device of the coating pattern applied to the sheet,
A plurality of cameras arranged in a shooting direction of a horizontal line orthogonal to the sheet conveying direction;
A synchronization signal generator for issuing a command for photographing the sheet simultaneously with the plurality of cameras;
A video signal selector switch for sequentially switching at least one of a horizontal scanning signal and a vertical scanning signal of a video imaged by a command of the synchronization signal generator;
The image processing device is characterized in that it includes image processing means for sequentially taking in the horizontal scanning signal or the vertical scanning signal switched by the video signal changeover switch to create a composite video.

In claim 5, in the shape measuring device of the coating pattern applied to the sheet according to claim 4,
Each of the plurality of cameras has an average value calculation circuit for calculating an average value of all or part of the horizontal scanning of the captured image, a sample hold circuit for holding the calculated average value, and the sample hold circuit holds the average value. It is possible to synthesize the vertical video signal changes of multiple cameras by outputting the average value of the specified horizontal scanning range of each camera for a certain period of horizontal scanning. Output.

In claim 6, in the shape measuring device of the coating pattern applied to the sheet according to claim 5,
A comparator for comparing the average value of the video signal with a threshold value is provided.

In claim 7, in the shape measuring device of the coating pattern applied to the sheet,
At least one camera disposed in a photographing direction of a horizontal line perpendicular to the sheet conveying direction;
At least one camera arranged orthogonal to the sheet conveying direction and arranged by turning 90 degrees in the imaging direction of the horizontal line;
At least one camera arranged in the photographing direction of a horizontal line orthogonal to the sheet conveyance direction or at least one camera arranged by turning the photographing direction of the horizontal line 90 degrees simultaneously or separately A synchronization signal generator that issues a command to shoot,
A video signal changeover switch is provided for sequentially switching at least one of a horizontal scanning signal and a vertical scanning signal of an image taken in accordance with a command from the synchronization signal generator.

In claim 8, in the shape measuring device of the coating pattern applied to the sheet according to claim 7,
The image processing device is characterized in that it includes image processing means for sequentially taking in the horizontal scanning signal or the vertical scanning signal switched by the video signal changeover switch to create a composite video.

In claim 9, in the shape measuring device of the coating pattern applied to the sheet according to claim 7,
At least one camera arranged in the horizontal line shooting direction perpendicular to the sheet conveyance direction, and arranged perpendicular to the sheet conveyance direction and rotated 90 degrees in the horizontal line imaging direction At least one camera can arbitrarily switch the shooting direction to any one of the shooting directions.

In Claim 10, in the shape measuring apparatus of the coating pattern coated on the sheet according to Claims 4 to 9 ,
A displacement sensor for measuring the distance between the plurality of cameras and the sheet, and using the relationship between the output of the displacement sensor and the distance between the plurality of cameras and the sheet obtained in advance and the imaging magnification; The measurement value of the coating pattern measured with a camera is corrected.

In Claim 11, in the shape measuring apparatus of the coating pattern coated on the sheet according to Claims 4 to 10 ,
The sheet is a battery electrode.

  According to claims 1 to 3 and 4, a plurality of cameras arranged in a photographing direction of a horizontal line perpendicular to the sheet conveyance direction, and a horizontal scanning signal of a photographed image obtained by photographing the sheet simultaneously with the plurality of cameras Alternatively, since at least one of the vertical scanning signals is sequentially switched and fetched into the image processing means, and at least one of the horizontal scanning signal and the vertical scanning signal of the captured video is synthesized, the simultaneity of the measurement position in the transport direction can be ensured. As a result, accurate width dimension measurement becomes possible.

  According to claims 5 and 6, by outputting the average value of the designated range of horizontal scanning of each camera for a certain period of horizontal scanning, the video signal changes in the vertical direction of multiple cameras are synthesized and output, and the transport direction Since the average value of these lines can be combined into one video signal, it is possible to measure the coating start and end dimensions without increasing the size of the video capture hardware. Further, by comparing the averaged individual line signal with a threshold value by a comparator, it is possible to detect the coating start and end dimensions without performing image processing.

  According to Claims 7, 8, and 9, at least one camera disposed in the horizontal line photographing direction perpendicular to the sheet conveying direction and the horizontal line photographing direction disposed perpendicular to the sheet conveying direction And at least one camera arranged by turning 90 degrees and at least one camera arranged in the horizontal line shooting direction orthogonal to the sheet conveying direction or arranged by turning 90 degrees in the horizontal line shooting direction A synchronous signal generator that issues a command for photographing a sheet simultaneously or separately with at least one camera, and an image that sequentially switches at least one of a horizontal scanning signal and a vertical scanning signal of the image captured according to the command of the synchronous signal generator Image processing to create a composite video by sequentially taking in the horizontal scanning signal or vertical scanning signal switched by the signal selector switch and the video signal selector switch Means, and the shooting direction can be arbitrarily switched to any shooting direction,

  Even if the number of cameras increases, it is possible to select one with only one image input means and low-spec by consolidating into two channels, thus reducing the system price. In addition, regarding image processing, the amount of information after reproducing an image for each camera is only one-tenth of the number of cameras. Since the direction to be detected is also clear, the image processing is light.

  According to claim 10, since the displacement sensor for measuring the distance between the plurality of cameras and the sheet is provided, it is possible to know the change in the distance between the camera and the sheet. Based on the change in dimensions, the magnification variation due to the lens distance is corrected, and accurate dimension measurement becomes possible.

It is a schematic block diagram of the measuring device of the coating pattern which shows an example of embodiment of this invention. FIG. 2 is an explanatory diagram showing a state of switching of images captured by the apparatus of FIG. It is a block block diagram of the processing circuit for one camera. It is explanatory drawing which shows the video signal of each camera, and the synthesized signal after a process. It is a block block diagram which shows another Example. It is explanatory drawing which shows the taking-in state of the horizontal line signal in FIG. It is a conceptual diagram which shows an example of the conventional coating pattern measuring apparatus. It is explanatory drawing which shows a mode that the magnitude | size of an image changes when a general lens is used. It is a schematic block diagram of the conventional coating pattern measuring apparatus.

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1A and FIG. 1B are schematic configuration diagrams of an apparatus for measuring a coating pattern applied to a sheet showing an example of an embodiment of the present invention.
In FIGS. 1A and 1B, coating patterns 2 to 5 are applied on a sheet 1, and the sheet 1 is conveyed on a conveying machine (not shown) from the back side to the near side of the paper at a constant speed. Yes.

Then, four cameras 6 arranged in series in the direction perpendicular to the sheet flow (arrow Y) direction (arrow X) and the coating pattern applied to the sheet 1 are arranged in the horizontal line shooting direction. Take an image at ~ 9 and measure.
In the present invention, the horizontal scanning direction perpendicular to the sheet flow direction is defined as the “horizontal line shooting direction”.
The imaging timing is synchronized by the synchronization signal generator 20 for both vertical scanning and horizontal scanning. Video signals output from the cameras 6 to 9 are switched by the video signal changeover switch 10 and taken into the image processing computer 11 equipped with an image input board (not shown).

In the present invention, the simultaneous imaging with the cameras 6 to 9 used for measurement is different from the conventional example.
FIG. 2 shows how the captured images are switched. The image taken by the camera 6 shown in FIG. 1 is replaced with the image of the camera a in FIG. 2, and similarly, the camera 7 is replaced with the camera b, the camera 8 is replaced with the camera c, and the camera 9 is replaced with the image of the camera d. For easy understanding, the shape of the image is different from that shown in FIG.

  The video signal of the camera is output while scanning in order from the top (in the case of an interlaced camera, there are a field for outputting an even line and a field for outputting an odd line every other line. A progressive camera, in which all lines are output in sequence, will be described here, but the concept is the same for an interlaced camera, so the description is omitted here).

  When the first horizontal line of the video a photographed by the camera 6 is output, the video signal change-over switch 10 shown in FIG. At the time when the second horizontal line of the video b photographed by the camera 7 is output, the video signal selector switch 10 shown in FIG. 1 is switched to the video c photographed by the camera 8. When the third horizontal line of the camera 8 is output, the video signal selector switch 10 shown in FIG. At the time when the fourth horizontal line of the video d photographed by the camera 9 is output, the video signal changeover switch 10 shown in FIG. ...

  Similarly, every time one line is output, the video signal selector switch 10 is switched to the next camera. The switching timing is controlled by the synchronization signal generator 20. In this way, a composite video as shown in FIG. 2e is taken into the image processing computer 11 in FIG.

  Since the imaging of each camera is performed at the same time, the imaging range is at the same timing with respect to the transport direction as indicated by the dotted lines in FIG. Since the horizontal signals from each camera are sequentially captured, it cannot be said that they are completely at the same point. However, for example, when the imaging range is 64 mm x 48 mm and this is captured at 640 pixels x 480 pixels, the size of one horizontal line is 0.1 mm. .

  Therefore, when the images are sequentially captured by four cameras, the maximum positional deviation in the conveyance direction is 0.3 mm (64/640 × 3), which is a negligible positional deviation. The image processing computer 11 can reproduce the video of each camera by classifying the images for each line from the synthesized video. In this case, the number of pixels in the vertical direction of the video of each camera is 1/4, but the dimensions of the positions of the measurement points 16 to 19 shown in FIG. 1 can be obtained.

  Next, an embodiment for measuring the dimension in the transport direction will be described with reference to FIGS. Using the above technique, it is possible to almost ensure the measurement in the conveyance direction, but when measuring the length in the conveyance direction of the coating, it is necessary to measure the information in the conveyance direction of each camera without omission.

FIG. 3 is a block diagram of a processing circuit for one camera according to the present invention, and FIG. 4 shows a video signal of each camera and a combined signal after processing.
In FIG. 3, A indicates a signal of one horizontal line of the camera 6, for example. The range in which this signal is averaged is the range indicated by arrow B. Reference numeral 45 denotes an integration time setting circuit that turns on the gate for a time corresponding to the average processing B. Reference numeral 43 denotes a voltage generator that generates a constant voltage (for example, about 0.5 V since video signals are often set to about 1 V peak). 44 and 46 are first and second integrators.

A divider 47 divides the output of the first integrator 44 by the output of the second integrator 46. 48 is a sample and hold circuit for holding the output of the divider 47, and 49 is a changeover switch.
In the configuration described above, the signal input to the first integrator 44 is integrated only while the gate of the integration time setting circuit 45 is ON. That is, if the line signal A is given by f (t), the output Vi of the first integrator 44 is

It is. Here, T corresponds to the time of the average range B. When the voltage of the voltage generator 43 is α, the output Vr of the second integrator 46 is

It is. Since these are input to the divider 47, the output Vd of the divider 47 is

And is proportional to the average value of time T of f (t). The output Vd of the divider 47 is held by the sample hold circuit 48.
Such a circuit corresponding to the number of cameras is prepared and connected to the changeover switch 49.

  Next, the image composition process will be described with reference to FIG. The average value of the portion corresponding to the average range B in the signal for one line of the image a1 of the camera 6 is held by the sample hold circuit 48 using the circuit of FIG.

  Similarly, the average value of the portion corresponding to the average range b2 in the signal for one line of the video image b1 of the camera 7 is sampled and held using the same circuit as in FIG. The same applies to one line of camera 8 and camera 9 below. When scanning of the next line starts, the average value of the camera 6 is output for a time corresponding to 1/4 of one line. The average value of the camera 7 is output in the next 1/4 time.

  The average value of the camera 8 is output in the next 1/4 time. The average value of the camera 9 is output in the next 1/4 time. The two lines of the composite image include the average value level of camera 6, the average value level of camera 7, the average value level of camera 8, and the average value level of camera 9 for 1/4 time each. Become.

  Thereafter, the same processing is performed for the subsequent lines. The obtained video is a composite image as shown by e 'in FIG. If this image is captured in the image processing computer 11 shown in FIG. 1, the change in the video signal in the vertical direction of each camera can be detected for each line, so that the dimension in the transport direction of the coating pattern can be accurately measured. .

  3 is a comparator, and can detect that the output (average value) of the divider 47 exceeds a certain value or decreases. By using this to detect the difference in video output due to the difference in reflectance between the coating pattern and the substrate, it is possible to detect the beginning or end of the coating pattern without using an image processing means.

  FIG. 5 shows another embodiment. In this example, three rectangular coating patterns 2a, 2b, and 2c are intermittently applied to the base sheet 1 in the flow direction. In this embodiment, 14 cameras 51 to 64 are imaged and measured in a state where they are arranged in series in a direction perpendicular to the sheet flow direction (conveyance direction). Also in this embodiment, the direction of horizontal scanning in a state perpendicular to the sheet flow direction is defined as the “horizontal line shooting direction”.

  In the figure, the cameras 52, 58, 62 are shown by turning the shooting direction of the horizontal line by 90 degrees, but a turning mechanism (not shown) may be provided in all cameras, It may be provided only in the camera. Further, although 14 cameras are shown in the figure, the number may be increased or decreased depending on the state of the coating pattern, and an unnecessary camera may be turned off by the setting unit 70.

  Reference numeral 71 denotes a video signal switching means, which includes a synchronization signal generator 72, a video switch 73, and image composition means 74a and 74b. An image processing means (CPU) 75 includes an image input means 76, an image processing section 77, a determination section 78, and the setting section 70 described above.

  In addition to turning off the unnecessary camera shooting function, the setting unit 70 selects both or one of the image compositing means 74a and 74b, selects either, and in other cases, the shooting is performed in the horizontal line shooting direction. It also has a function of switching between displaying an image of the camera and displaying an image of the camera rotated 90 degrees in the horizontal line shooting direction.

  In the above configuration, for example, when the cameras 51 to 64 are all arranged so as to face the same horizontal line (the cameras 52, 58, and 62 shown in FIG. 5 are oriented in the horizontal line shooting direction), synchronization is performed. The signal generator 72 transmits an imaging signal to the cameras 51 to 64 at the same timing. The signal is synchronized with both vertical scanning and horizontal scanning. The video signals output from the cameras 51 to 64 are switched by a video signal selector switch 73 constituting the image processing means 75, synthesized by the image synthesis means 74a, and mounted with an image processing section 77 via the image input means 76. It is taken into the image processing means 75.

FIG. 6 shows how the captured images are switched, and video signals from the cameras are output while scanning from cameras 51 to 64 in order.
Returning to FIG. 5, when the first horizontal line of the camera 51 is output, the video signal selector switch 73 is switched to the camera 2. When the second line of the camera 52 is output, the video signal selector switch 73 is switched to the camera 53. When the third line of the camera 3 is output, the video signal switch 73 is switched to the camera 54. ... Similarly, sequentially switch to camera 64, return to camera 51, and repeat in the same manner.

  In this way, the video signal selector switch 73 is sequentially switched every time one line is output. The switching timing is controlled by the synchronization signal generator 72. In this way, a synthesized video is created by the image synthesizing means 74a, and the image is taken into the image processing means 75 via the image input means 76.

  Since the imaging of each camera is performed simultaneously, the imaging range is at the same timing with respect to the transport direction. Since the horizontal signals from each camera are sequentially captured, it cannot be said that they are completely at the same point. However, for example, when the imaging range is 50 mm x 37.5 mm and this is captured at 640 pixels x 480 pixels, the size of one horizontal line is 0.078 mm ( 640/50).

  When captured sequentially with 14 cameras, the maximum displacement in the transport direction is 1.09 mm (0.078 × 14), which is negligible for the purpose of measuring the width. In addition, when viewed as a single camera, the width is measured by every camera every 0.078 mm x 15 times = 1.17 mm, and feedback sufficiently earlier than the coating machine control cycle can be applied.

  In the image processing means 75, the images of each camera can be reproduced by classifying the images for each line from the synthesized video by the image processing unit 77. In this case, the number of pixels in the vertical direction of the video of each camera is 1/14, and the number of pixels is small, so that the processing load can be greatly reduced.

The coating width measurement is as described above. Next, the coating length (= front / back coating position deviation) measurement will be described.
As shown in FIG. 5, the cameras are arranged in a line substantially perpendicular to the sample transport direction, and each camera is held by a mechanism (not shown) that can turn 90 degrees. Specifically, it is supported by a bearing so as not to cause optical axis vibration, and is driven by a small solenoid or a micromotor. Although the coating pattern varies depending on the type, it is easy to grasp the area to be inspected.

  That is, if the installation position of the camera (= shooting range) is known in advance, a camera that is convenient for measuring the coating width and a camera that is convenient for measuring the coating length Can be determined. Therefore, when measuring the coating length, only the camera used for measuring the coating length is turned 90 degrees. In this state, the coating length can be detected by inserting horizontal signals one by one as in the width measurement and synthesizing the images. The image synthesizing means 74b shows a state in which the cameras 51 to 64 are all turned 90 degrees to synthesize the coating length image.

It is also possible to determine the role of the camera in advance according to the type in the setting unit 70 constituting the image processing means 75 so that each camera can be set when changing the type.
As shown in Fig. 5, only the cameras 53, 58, and 62 are turned 90 degrees, and video signals are allocated and combined into two screens, a width measurement image and a coating length measurement image. The image is sent to the image processing means 75 equipped with the input means 76, and the images of each camera are reproduced by classifying the images for each line from the synthesized video as described above. Then, various corrections can be performed to calculate the width and length dimensions of the coated portion.

  According to the above-described configuration, since images are simultaneously captured by a plurality of cameras, it is possible to ensure the synchronism of the measurement position in the transport direction, and to accurately measure the width dimension. In addition, although the number of cameras has been described here as 14 units, the width direction end detection and the flow direction end detection are performed by two units of one camera for width measurement and one camera for coating length measurement. It is possible to measure at intervals of 1.17mm.

  Even if the number of cameras is increased, it is possible to select one having only one image input means 76 and low specifications by collecting the images into two channels, and the system price can be reduced. In addition, regarding image processing, the amount of information after reproducing an image for each camera can be reduced to one camera number, and there are two types of directions to be detected, so the load for image processing can be reduced.

  Still another embodiment will be described. In FIG. 1, a displacement meter 21 is attached so that the position relative to the camera does not change, and displacement data of the displacement meter 21 is connected to the image processing computer 11. As described above, by suppressing the viewing angle of the camera to be small, the variation of the magnification with respect to the displacement in the optical axis direction is reduced, but an error is still generated.

  Data on how the measured value of the dimension changes when the distance between the camera and the sheet 1 changes is measured and stored in the image processing computer 11 in advance. By measuring the distance between the sheet and the camera with the displacement meter 21 shown in FIG. 1 and importing it into the image processing computer 11, correction of the dimensional measurement data by the camera is made to eliminate the influence of the fluctuation in the distance between the sheet and the camera. Can do.

Further, by installing an image input board having a plurality of image input means on the image processing computer, it is possible to capture images from a larger number of cameras.
The average value circuit is not limited to the one using the integrators 44 and 46 and the divider 47 as described in the explanation of FIG. 3, but may be a digital process using A / D conversion or integration. A circuit that scales the value is also possible.

The above description merely shows a specific preferred embodiment for the purpose of explanation and illustration of the present invention. For example, the number of cameras may be two or more.
Therefore, the present invention is not limited to the above-described embodiments, and includes many changes and modifications without departing from the essence thereof.

1 Base sheet
2 ~ 5 coating pattern
6-9, 31, 51-64 cameras
10, 49 Video signal selector switch
11 Image processing computer
12-15 Camera imaging range
16-19 measurement points
20, 72 Sync signal generator
21 Displacement meter
30 lenses
32 Coating part
33 attention
43 Voltage generator
44 1st integrator
45 Integration time setting circuit
46 Second integrator
47 Divider
48 Sample hold circuit
50 Comparator
70 Camera position setting section
71 Video signal switching means
73 Video selector switch
74 Image composition means
75 Image processing means
76 Image input means
77 Image processor
78 Judgment part

Claims (11)

In the method for measuring the shape of the coating pattern applied to the sheet,
1) A step of arranging a plurality of cameras in a photographing direction of a horizontal line perpendicular to the sheet conveying direction, and photographing the sheet with the plurality of cameras,
And 2) coating the sheet, including a step of synchronizing at least one of a horizontal scanning signal and a vertical scanning signal of the photographed video with the horizontal scanning and sequentially switching the horizontal scanning signals of the plurality of cameras into the image processing means. Method for measuring the shape of the applied coating pattern.   The method for measuring a shape of a coating pattern applied to a sheet according to claim 1, wherein the timing of photographing is simultaneous.   2. The method for measuring the shape of a coating pattern applied to a sheet according to claim 1, further comprising a step of synthesizing at least one of a horizontal scanning signal and a vertical scanning signal of the captured image. In the shape measuring device for the coating pattern applied to the sheet,
A plurality of cameras arranged in a shooting direction of a horizontal line orthogonal to the sheet conveying direction;
A synchronization signal generator for issuing a command for photographing the sheet simultaneously with the plurality of cameras;
A video signal selector switch for sequentially switching at least one of a horizontal scanning signal and a vertical scanning signal of a video imaged by a command of the synchronization signal generator;
An apparatus for measuring the shape of a coating pattern applied to a sheet, comprising image processing means for sequentially taking in a horizontal scanning signal or a vertical scanning signal switched by the video signal changeover switch and creating a composite video.   Each of the plurality of cameras has an average value calculation circuit for calculating an average value of all or part of the horizontal scanning of the captured image, a sample hold circuit for holding the calculated average value, and the sample hold circuit holds the average value. It is possible to synthesize the vertical video signal changes of multiple cameras by outputting the average value of the specified horizontal scanning range of each camera for a certain period of horizontal scanning. 5. The apparatus for measuring a shape of a coating pattern applied to a sheet according to claim 4, wherein   6. The apparatus for measuring a shape of a coating pattern applied to a sheet according to claim 5, further comprising a comparator that compares an average value of the video signal with a threshold value. In the shape measuring device for the coating pattern applied to the sheet,
At least one camera disposed in a photographing direction of a horizontal line perpendicular to the sheet conveying direction;
At least one camera arranged orthogonal to the sheet conveying direction and arranged by turning 90 degrees in the imaging direction of the horizontal line;
At least one camera arranged in the photographing direction of a horizontal line orthogonal to the sheet conveyance direction or at least one camera arranged by turning the photographing direction of the horizontal line 90 degrees simultaneously or separately A synchronization signal generator that issues a command to shoot,
An apparatus for measuring the shape of a coating pattern applied to a sheet, comprising a video signal switching switch for sequentially switching at least one of a horizontal scanning signal and a vertical scanning signal of a video imaged in accordance with a command of the synchronization signal generator .   8. The coating applied to the sheet according to claim 7, further comprising image processing means for creating a composite image by sequentially taking in a horizontal scanning signal or a vertical scanning signal switched by the video signal selector switch. Pattern shape measuring device.   At least one camera arranged in the horizontal line shooting direction perpendicular to the sheet conveyance direction, and arranged perpendicular to the sheet conveyance direction and rotated 90 degrees in the horizontal line imaging direction 8. The apparatus for measuring a shape of a coating pattern applied to a sheet according to claim 7, wherein the at least one camera can arbitrarily switch the photographing direction to any one of the photographing directions. A displacement sensor for measuring the distance between the plurality of cameras and the sheet, and using the relationship between the output of the displacement sensor and the distance between the plurality of cameras and the sheet obtained in advance and the imaging magnification; The apparatus for measuring a shape of a coating pattern applied to a sheet according to any one of claims 4 to 9 , wherein a measured value of the coating pattern measured by a camera is corrected. The apparatus for measuring a shape of a coating pattern applied to a sheet according to claim 4 , wherein the sheet is a battery electrode.