JP2010025799A - Apparatus for detecting boundary of covering film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique capable of computing a boundary position of a covering film formed on a battery electrode-use sheet etc., even when the covering film is made thin. <P>SOLUTION: An apparatus which detects a boundary of the covering film formed on the battery electrode-use sheet 2 (object to be measured), includes: laser light sources 41, 42 (irradiation means) for irradiating a surface of the battery electrode-use sheet 2 with slit light; CCD cameras 51, 52 (photographing means) for photographing the surface of the battery electrode-use sheet 2 onto which the slit light is projected; a linewidth-variation point specifying means 65 (first specifying means) for specifying a linewidth-variation point where a linewidth of the photographed slit light varies discontinuously in the images photographed by the CCD cameras 51, 52; and a first boundary computing means 68 for computing the boundary position of the covering film formed on the surface of the battery electrode-use sheet 2, based on the position of the linewidth-variation point specified in the photographed image. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an apparatus for detecting a boundary of a film formed on a surface of a measurement object.

A battery electrode sheet in which a film is formed on a current collector sheet is known.
In a battery electrode sheet used in a lithium ion secondary battery or the like, a film of an active material layer is formed on a current collector sheet of metal foil. The active material layer is formed by applying an active material paste obtained by kneading an active material powder and a fixing agent in water or an organic solvent to the surface of the current collector sheet and drying it. When the active material paste is applied to the battery electrode sheet, the active material paste is applied to a region that is different from the region where the active material layer is to be formed, and the active material layer is formed in a region different from the region where the active material layer is to be formed. There is. This adversely affects battery performance. Therefore, when manufacturing a battery, it is necessary to inspect whether or not the active material layer formed on the battery electrode sheet is correctly formed in the formation scheduled region.
Patent Document 1 discloses an apparatus that detects the boundary position of a coating formed on a battery electrode sheet by an optical method.

  As an optical technique for detecting the boundary position of a film formed on a measurement object such as a battery electrode sheet, a light cutting method using slit light (linear light) is generally used. In the battery electrode sheet 102 of FIG. 20, a coating 130 is formed on the current collector sheet 110. Such an inspection apparatus for inspecting the battery electrode sheet 102 includes irradiation means for irradiating the surface of the battery electrode sheet 102 obliquely with the slit light L toward the surface. In addition, the inspection apparatus includes an imaging unit such as a CCD camera that images the battery electrode sheet 102 onto which the slit light L is projected. The inspection apparatus specifies a position change point a11 where the position of the captured slit light L (the position in the length direction of the battery electrode sheet 102) changes discontinuously from the image captured by the imaging means (see FIG. 21). . The inspection apparatus calculates the boundary position A11 of the coating 130 formed on the battery electrode sheet 102 from the position of the position change point a11 (position in the width direction of the battery electrode sheet 102). The inspection device can determine whether or not the positional deviation of the coating 130 is within an allowable range, and can inspect whether or not the coating 130 is correctly formed in the formation scheduled range.

JP 2000-353514 A

As shown in FIG. 20, when the coating 130 formed on the current collector sheet 110 is thick, the step between the current collector sheet 110 and the coating 130 is large. Therefore, it is easy to specify the position change point a11 (see FIG. 21) where the position of the captured laser beam L changes discontinuously and greatly. However, when the coating 130 is thin, the step between the current collector sheet 110 and the coating 130 is small, and it is difficult to specify the position change point a11. In this case, it is difficult to specify the boundary position A11 of the coating 130 formed on the battery electrode sheet 102.
The present invention solves the above problems. The present invention provides a technique capable of calculating the boundary position of a film formed on an object to be measured even if the film is thin.

The present invention is embodied in an apparatus for detecting a boundary position of a film formed on a measurement object. The apparatus includes an irradiating unit, an imaging unit, a first specifying unit, and a first boundary calculating unit.
The irradiation means irradiates the surface of the measurement object with slit light. The photographing means photographs the surface of the measurement object on which the slit light is projected. The first specifying unit specifies a line width change point at which the line width of the captured slit light changes discontinuously from the photographed image by the photographing unit. The first boundary calculation means calculates the boundary position of the film formed on the surface of the measurement object from the position of the line width change point in the specified captured image.

In the above-described apparatus, the boundary position of the film formed on the measurement object is calculated based on the position of the line width change point at which the line width of the captured slit light changes discontinuously. When the light reflectance of the surface irradiated with the slit light is large (for example, when the current collector sheet is a battery electrode sheet), the reflected light of the slit light has a high intensity. In this case, in the photographed image obtained by photographing the measurement object, the slit light has a wide line width. On the other hand, when the light reflectance of the surface irradiated with the slit light is small (for example, when it is an active material layer of a battery electrode sheet), the intensity of the reflected light of the slit light becomes weak. In this case, in the photographed image obtained by photographing the measurement object, the line width of the slit light is photographed narrowly. Accordingly, in the image obtained by photographing the measurement object, the line width of the photographed slit light changes discontinuously at the boundary position of the film. Thereby, the boundary position of the film formed on the measurement object can be calculated.
According to the above-described apparatus, if there is a difference in light reflectance between the inside and outside of the boundary of the coating, the boundary position of the coating can be detected. For example, the boundary position of the coating formed on the battery electrode sheet can be correctly detected even if the coating is thin.

It is preferable that the apparatus described above further includes second specifying means and second boundary calculating means.
The second specifying means specifies a position change point where the position of the shot slit light (position in the width direction of the slit light) changes discontinuously from the image taken by the imaging means. The second boundary calculation means calculates the boundary position of the film formed on the surface of the measurement object from the position of the position change point in the specified captured image. The irradiating means irradiates slit light obliquely to the surface of the measurement object.
There is a step due to the thickness of the coating between the surface of the coating (for example, the surface of the active material layer) and the surface on which the coating is formed (for example, the surface of the current collector sheet). Therefore, in the photographed image obtained by photographing the measurement object, the position of the slit light photographed on the surface of the film and the position of the slit light photographed on the surface on which the film is formed change discontinuously. Therefore, it is possible to calculate the boundary position of the film formed on the surface of the measurement object by specifying the point at which the position of the photographed slit light changes discontinuously (typically the point to be cut). it can.
According to the device described above, there is a corresponding step between the surface of the coating and the surrounding surface (whether the coating that detects the boundary position is somewhat thick), or between the surface of the coating and the surrounding surface, If there is a difference in reflectance with respect to the irradiated slit light, the boundary position can be calculated. For example, the boundary between the first film where the film thickness is thick but the light reflectance is not different from the surroundings, and the boundary between the second film where the film thickness is thin but the light reflectance is significantly different from the surroundings. Can also be detected simultaneously.

The inspection apparatus described above preferably further includes third specifying means and third boundary calculating means.
The third specifying means specifies a color change point at which the color (at least one of brightness, hue, and saturation) of the photographed battery electrode sheet changes discontinuously from the photographed image by the photographing means. The third boundary calculation means calculates the boundary position of the coating formed on the battery electrode sheet from the position of the color change point in the specified captured image.
According to this configuration, there is a difference in reflectance with respect to the irradiated slit light between the surface of the coating and the surrounding surface, or color (brightness, hue) between the surface of the coating and the surrounding surface. If there is a difference in at least one of the saturations), the boundary position can be calculated.

  According to the apparatus of the present invention, it is possible to calculate the boundary position of a film formed on a measurement object such as a battery electrode sheet even if the film is thin.

(1) At least one film is formed on the surface of the measurement object. The “boundary of the coating formed on the surface of the measurement object” may be the boundary between the sheet on which the coating is formed and the coating, or the boundary between the first coating and the second coating.
(2) When the measurement object is a battery electrode sheet, the “boundary of the film formed on the surface of the measurement object” may be a boundary position between the current collector sheet and the coating layer, or coating It may be a boundary position between the layer (first coating) and the active material layer (second coating).
(3) The current collector sheet is often formed using metal. In this case, the reflected light intensity of the slit light on the surface of the current collector sheet is high. The slit light is photographed with a wide line width.
(4) An active material layer or a coating layer is often formed as a film. In this case, the reflected light intensity of the slit light on the surface of the coating is weak. The slit light is photographed with a narrow line width.
(5) The slit light may be slit-like light, and is preferably laser light.
(6) The first specifying means only needs to specify the line width change point at which the line width of the captured slit light changes discontinuously, and the line width at each position may or may not be calculated. Good.
(7) In the second specifying means, it is only necessary to specify a position change point where the position of the captured slit light changes discontinuously (if it changes discontinuously in any direction). It may be calculated or not calculated.
(8) As a method of calculating the boundary position of the coating formed on the battery electrode sheet from the position change point by the second boundary calculation means, for example, a light cutting method can be used.
(9) The third specifying means may specify a color change point at which the color (at least one of brightness, hue, and saturation) of the photographed battery electrode sheet changes discontinuously. It may be calculated or not calculated.
(10) The irradiation unit may include a plurality of irradiation devices. For example, it is preferable to include an irradiation device that includes the boundary position at one end in the width direction of the battery electrode sheet in the irradiation range and an irradiation device that includes the boundary position at the other end in the irradiation range.
(11) The photographing unit may include a plurality of photographing devices. It is preferable that an imaging device is provided for each irradiation device.
(12) The second specifying means specifies a position change point at which the position of the captured slit light changes discontinuously from one captured image. The third specifying means specifies a color change point at which the color of the captured battery electrode sheet changes discontinuously from the captured image other than the captured image. The boundary position calculated based on the position change point specified by the second specifying means and the boundary position calculated based on the color change point specified by the third specifying means are synchronized, and the same position (the length of the battery electrode sheet) It is determined whether or not there is a defect at the position in the vertical direction.
(13) The first specifying unit specifies a line width change point where the line width of the shot slit light changes discontinuously from one shot image, and the second specifying unit takes a shot from the same shot image. The position change point where the position of the slit light changes discontinuously is specified. Both the line width change point and the position change point can be specified from one captured image.

The main features of the embodiments described below are listed.
(Feature 1) The battery electrode sheet has a laminated structure in which a current collector sheet, a coating layer, and an active material layer are laminated in order.
(Characteristic 2) The first specifying unit determines the line width of the reflected light by detecting a pixel whose luminance is saturated with the reflected light of the slit light among the pixels of the captured image.
(Characteristic 3) The second specifying means determines the color by detecting the intensity of each of the RGB components of the pixels of the captured image.
(Feature 4) The inspection apparatus can determine whether or not the active material layer is in a good state where it is not in direct contact with the current collector sheet.
(Characteristic 5) The inspection apparatus can determine whether or not the width of the active material layer is within an allowable range.
(Feature 6) The inspection apparatus can determine whether or not the width of the coating layer is within an allowable range.
(Feature 7) Since the difference in reflected light intensity is large between the current collector sheet and the coating layer, the boundary position between the two can be calculated by the first boundary calculation means.
(Feature 8) Since there is a large color difference between the current collector sheet and the coating layer, the boundary position between the two can be calculated by the third boundary calculation means.
(Feature 9) Since there is a large step between the coating layer and the active material layer, the boundary position between the two can be calculated by the second boundary calculation means.
(Feature 10) If there is a corresponding step between the surface of the coating and the surrounding surface, or if there is a color difference between the surface of the coating and the surrounding surface, the boundary position is calculated. (FIG. 17; second embodiment).
In this case, the device for detecting the boundary of the film formed on the surface of the measurement object is:
Irradiation means for obliquely irradiating the surface of the measurement object with slit light;
Photographing means for photographing the surface of the measurement object onto which the slit light is projected;
Second specifying means for specifying a position change point at which the position of the captured slit light changes discontinuously from the image captured by the imaging means;
Second boundary calculation means for calculating the boundary position of the film formed on the surface of the measurement object from the position of the position change point in the identified captured image;
A third specifying means for specifying a color change point at which the color of the surface of the measured measurement object discontinuously changes from a photographed image by the photographing means;
Third boundary calculation means for calculating the boundary position of the film formed on the surface of the measurement object from the position of the color change point in the identified captured image;
It has.
Even with the above-described apparatus, even when the film thickness is small, the boundary position of the film can be calculated if there is a color difference between the surface of the coating and the surrounding surface.

Example 1
The battery electrode sheet 2 shown in FIG. 1 has a laminated structure in which a long current collector sheet 10, a coating layer 20, and an active material layer 30 are laminated in order.
The current collector sheet 10 is formed using a metal foil such as aluminum if the battery electrode sheet 2 is for a positive electrode of a battery. The current collector sheet 10 is formed using a metal foil such as copper if the battery electrode sheet 2 is for a negative electrode of a battery. The current collector sheet 10 is formed using a metal foil, and when the surface is irradiated with slit light, its reflected light intensity is strong.

  The coating layer 20 is formed on the current collector sheet 10. The width of the coating layer 20 (the length in the direction intersecting the length direction of the battery electrode sheet 2) is narrower than the width of the current collector sheet 10. The coating layer 20 contains a conductive agent (for example, carbon). When the surface of the coating layer 20 is irradiated with slit light, its reflected light intensity is weak. Further, the coating layer 20 is preferably thinner than the active material layer 30 because the exchange of ions between the active material layer 30 and the current collector sheet 10 is relayed.

  The active material layer 30 is formed on the coating layer 20. The active material layer 30 is narrower than the width of the coating layer 20. The active material layer 30 and the current collector sheet 10 are not in direct contact. If the battery electrode sheet 2 is for a positive electrode of a battery, the active material layer 30 is formed using a mixture obtained by mixing and melting a positive electrode active material, a conductive agent (for example, carbon), a binder, and the like with an organic solvent. Yes. If the battery electrode sheet 2 is for a negative electrode of a battery, the active material layer 30 is formed using a material obtained by mixing and melting a negative electrode active material, a conductive agent (for example, carbon), a binder, and the like with an organic solvent. Yes. When the active material layer 30 is irradiated with slit light on its surface, its reflected light intensity is weak. In order to increase the capacity of the battery, the active material layer 30 is relatively thick.

  The lithium ion secondary battery has a battery electrode sheet 2 formed for a positive electrode and a battery electrode sheet 2 formed for a negative electrode, wound around a separator and filled with an electrolyte solution. It is comprised by attaching to.

In FIG. 2, the inspection apparatus 1 of the sheet | seat 2 for battery electrodes of a present Example is typically shown. FIG. 3 is a top view of the battery electrode sheet 2 when the inspection apparatus 1 is inspecting whether there is a defect while the active material layer 30 is formed.
In the current collector sheet 10 shown in FIGS. 2 and 3, the coating layer 20 having the formation width Z2 (Z2 <T) is already formed on the current collector sheet 10 having the width T. As shown in FIG. 2, the current collector sheet 10 is conveyed in the direction indicated by the arrow by the coating roller 5 with the surface on which the coating layer 20 is formed facing up. A paste material for forming the active material layer 30 is applied from the coating die 4 onto the coating layer 20 with a formation width Z1 (Z1 <Z2). Conditions relating to the application of the paste material by the coating die 4 are controlled by the coating control means 3.

  The inspection apparatus 1 inspects whether the active material layer 30 is applied without protruding from the coating layer 20 (whether the active material layer 30 is not in direct contact with the current collector sheet 10). Moreover, the inspection apparatus 1 inspects whether the formation width Z2 of the coating layer 20 is within an allowable range. Further, the inspection apparatus 1 inspects whether or not the formation width Z1 of the active material layer 30 is within an allowable range.

As shown in FIG. 2, the inspection apparatus 1 includes two laser light sources 41 and 42 (an example of irradiation means), two CCD cameras 51 and 52 (an example of imaging means), and a control device 60. Yes.
The laser light sources 41 and 42 irradiate a slit-shaped (linear) laser beam L toward the surface of the battery electrode sheet 2. As shown in FIG. 3, the laser light sources 41 and 42 are arranged so that both the boundary position between the current collector sheet 10 and the coating layer 20 and the boundary position between the coating layer 20 and the active material layer 30 are included in the irradiation range. The The laser light source 41 includes the boundary position on the right side (lower side in FIG. 3) in the traveling direction of the battery electrode sheet 2 indicated by an arrow in FIG. The laser light source 42 includes the boundary position on the left side (upper side in FIG. 3) in the traveling direction of the battery electrode sheet 2 in the irradiation range. The laser light sources 41 and 42 are inclined toward the traveling direction of the battery electrode sheet 2 and irradiate the laser light L obliquely with respect to the surface of the battery electrode sheet 2. On the surface of the battery electrode sheet 2, the slit-shaped laser light L is projected substantially perpendicularly to the boundary between the current collector sheet 10 and the coating layer 20 and the boundary between the coating layer 20 and the active material layer 30.

  The CCD camera 51 photographs the battery electrode sheet 2 onto which the laser light L from the laser light source 41 is projected from above. Laser light L from the laser light source 41 projected on the battery electrode sheet 2 is photographed in the photographed image by the CCD camera 51. The CCD camera 52 photographs the battery electrode sheet 2 onto which the laser light L from the laser light source 42 is projected from above. Laser light L from the laser light source 42 projected on the battery electrode sheet 2 is photographed in the photographed image by the CCD camera 52.

As shown in FIG. 2, the control device 60 includes a control unit 62, a storage unit 63, a position change point specifying unit 64 (an example of a second specifying unit), and a line width change point specifying unit 65 (an example of a first specifying unit). And second boundary calculation means 67 and first boundary calculation means 68.
The control means 62 is connected to the coating control means 3. The control unit 62 transmits to the coating control unit 3 conditions relating to the paste material being applied to the current collector sheet 10 by the coating die 4.
The control means 62 is connected to the CCD cameras 51 and 52. The control means 62 controls the conditions under which the CCD cameras 51 and 52 photograph the battery electrode sheet 2. Also, information on the captured image captured by the CCD cameras 51 and 52 is acquired.
The control means 62 is connected to the position change point specifying means 64. The control means 62 instructs the position change point specifying means 64 to specify the position change points a1 and b1 from the captured images E1 and E2 (see FIG. 5) taken by the CCD cameras 51 and 52.
The control means 62 is connected to the second boundary calculation means 67. The control means 62 instructs the second boundary calculating means 67 to calculate the boundary positions A1 and B1 from the position change points a1 and b1 specified by the position change point specifying means 64. The control means 62 acquires information on the boundary positions A1 and B1 calculated by the second boundary calculation means 67.
The control means 62 is connected to the line width change point specifying means 65. The control means 62 instructs the line width change point specifying means 65 to specify the line width change points a2 and b2 from the captured images E1 and E2 (see FIG. 5) taken by the CCD cameras 51 and 52.
The control means 62 is connected to the first boundary calculation means 68. The control means 62 instructs the first boundary calculation means 68 to calculate the boundary positions A2 and B2 from the line width change points a2 and b2 specified by the line width change point specification means 65. The control means 62 acquires information on the boundary positions A2 and B2 calculated by the first boundary calculation means 68.
Further, the control means 62 calculates the width Z1 of the active material layer 30 from the information on the boundary positions A1 and B1 acquired from the second boundary calculation means 67. The width Z2 of the coating layer 20 is calculated from the information on the boundary positions A2 and B2 acquired from the first boundary calculation means 68. It is determined from the boundary positions A1, A2, B1, B2, the width Z1, and the width Z2 whether or not a defect has occurred in the battery electrode sheet 2. If a defect has occurred, the type of defect to be described later is determined.
Further, the control unit 62 stores the boundary positions A1, A2, B1, and B2, the widths Z1 and Z2, and the types of defects, if any, in the storage unit 63 in association with the inspected positions.

With reference to FIG. 4 to FIG. 9, the operation in which the inspection apparatus 1 inspects whether or not the battery electrode sheet 2 is defective will be described in detail.
The program shown in the flowchart of FIG. 4 is executed by the control means 62 (see FIG. 2) of the control device 60. As the control means 62, for example, a CPU is used. The program shown in the flowchart is stored in a memory (not shown). The control means 62 reads and executes the program stored in the memory as appropriate. The memory may be built in the control means 62.

As shown in FIG. 3, when the relative positional relationship among the laser light sources 41 and 42, the CCD cameras 51 and 52, and the battery electrode sheet 2 is set, an operation for starting an inspection is performed. 1 starts the operation of inspecting the battery electrode sheet 2.
In the process of step S1 shown in FIG. 4, the control unit 62 performs zero adjustment of the first boundary calculation unit 68 and the second boundary calculation unit 67 using a reference sample having a reference width T with a known width. As shown in FIG. 5, the first boundary calculation means 68 and the second boundary calculation means 67 are adjusted so that each end in the traveling direction of the current collector sheet 10 becomes a zero point.
Next, the control means 62 proceeds to the process of step S1a. In step S1a, the width Z1, the lower limit threshold Z1L and the upper limit threshold Z1H of the active material layer 30, the lower limit threshold Z2L and the upper limit threshold Z2H of the width Z2 of the coating layer 20 are determined.
Next, the control means 62 proceeds to the process of step S1b, and sets the initial value C0 to the counter value C.

Next, the control means 62 proceeds to the processing in step S2 and step S6 in FIG.
In step S2, the control means 62 instructs the position change point specifying means 64 to specify the position change point from the captured images E1 and E2 (see FIG. 5) taken by the CCD cameras 51 and 52.
As shown in FIG. 6, the current collector sheet 10, the coating layer 20, and the active material layer 30 differ in the position where the laser light L is reflected (the position in the longitudinal direction of the battery electrode sheet 2). On the current collector sheet 10 of FIG. 6, the laser light L is reflected at the position L11. On the coating layer 20, the laser beam L is reflected at the position L21. On the active material layer 30, the laser beam L is reflected at the position L31. Therefore, as shown in FIG. 5, the laser light L is imaged at positions L11, L21, and L31 in the captured image E1 captured by the CCD camera 51. Similarly, in the captured image E2 captured by the CCD camera 52, the laser beam L is captured at positions L12, L22, and L32. The active material layer 30 is thick and the coating layer 20 is thin. Therefore, the distance between the position L21 and the position L31 is large, and the distance between the position L11 and the position L21 is small. Similarly, the distance between the position L22 and the position L32 is large, and the distance between the position L12 and the position L22 is small.
The position change point specifying unit 64 specifies position change points a1 and b1 whose positions (positions in the length direction of the battery electrode sheet 2) discontinuously change beyond a threshold value from the captured images E1 and E2. The position change point specifying means 64 specifies the positions of the position change points a1 and b1 in the width direction of the battery electrode sheet 2 (positions in the width direction of the battery electrode sheet 2).

Next, the control means 62 proceeds to the process of step S4 in FIG.
In step S4, the control means 62 instructs the second boundary calculation means 67 to calculate the boundary position from the positions of the position change points a1 and b1 (position in the width direction of the battery electrode sheet 2). The second boundary calculation means 67 calculates the boundary position A1 between the coating layer 20 and the active material layer 30 shown in FIG. 5 from the position of the position change point a1. In addition, the second boundary calculation unit 67 calculates the boundary position B1 between the coating layer 20 and the active material layer 30 from the position of the position change point b1.

Further, in step S6 of FIG. 4, the control means 62 specifies the line width change point from the captured images E1 and E2 (see FIG. 5) taken by the CCD cameras 51 and 52 to the line width change point specifying means 65. Instruct. The line width change point specifying means 65 specifies the range where the laser beam L is captured from the captured images E1 and E2, and the line width of the laser beam L (dimension in the length direction of the battery electrode sheet 2) is discontinuous. (Position in the width direction of the battery electrode sheet 2) is specified.
FIG. 7 shows the distribution of the luminance S in the line width direction P (the length direction of the battery electrode sheet 2) of the laser light L photographed in the photographed images E1 and E2. A graph G1 in FIG. 7 shows the luminance distribution of the laser light L projected on the current collector sheet 10, and a graph G2 in FIG. 7 shows the luminance distribution of the laser light L projected on the coating layer 20. Yes. A luminance value S1 in the figure indicates a value at which the luminance S of the pixel is saturated (the maximum value of the luminance S in the images E1 and E2). The line width change point specifying unit 65 specifies the ranges W11 and W21 in which the luminance S of the pixels is saturated in the captured images E1 and E2 as the range where the laser light L is captured.
The current collector sheet 10 is formed using a metal foil. Therefore, the reflected light intensity of the laser beam L reflected on the surface is strong and the peak value is high. As a result, as shown in the graph G1 in FIG. 7, the range (that is, the line width) W11 specified as the imaging range of the laser light L is widened. On the other hand, the coating layer 20 does not have gloss like the current collector sheet 10. Therefore, the reflected light intensity of the laser light L reflected on the surface is weak and the peak value is low. As a result, as shown in the graph G2 of FIG. 7, the range (that is, the line width) W21 specified as the imaging range of the laser light L is narrowed. Therefore, in the captured images E1 and E2, the line width of the captured laser beam L changes discontinuously at the boundary position between the current collector sheet 10 and the coating layer 20.
The line width change point specifying means 65 specifies the points where the line width of the laser beam L to be photographed is changed to a threshold value or more as the line width change points a2 and b2.

Next, the control means 62 proceeds to the process of step S8 in FIG.
In step S8, the control means 62 causes the first boundary calculation means 68 to determine the current collector sheet 10 and the coating layer 20 in the battery electrode sheet 2 from the positions of the line width change points a2 and b2 on the captured images E1 and E2. Instructs to calculate the boundary position of. The first boundary calculation means 68 calculates the boundary position A2 between the current collector sheet 10 and the coating layer 20 shown in FIG. 5 from the position of the line width change point a2. The first boundary calculation means 68 calculates the boundary position B2 between the current collector sheet 10 and the coating layer 20 from the position of the line width change point b2.

  Next, the control means 62 proceeds to the process of step S9 in FIG. The control means 62 acquires the boundary positions A1 and B1 calculated by the second boundary calculation means 67 and the boundary positions A2 and B2 calculated by the first boundary calculation means 68.

Next, the control means 62 proceeds to the process of step S10 in FIG.
The control means 62 determines whether or not the boundary position A1 is larger than the boundary position A2. When the boundary position A1 is larger than the boundary position A2 (for example, when the boundary position A1 is 5 mm and the boundary position A2 is 3 mm), the traveling direction of the battery electrode sheet 2 (the bottom indicated by the arrow in FIG. 5) The edge of the active material layer 30 on the right side (left side in FIG. 5) in the direction) is closer to the center than the edge of the coating layer 20. In this case, it is determined that the active material layer 30 on the right side in the traveling direction of the battery electrode sheet 2 and the current collector sheet 10 are not in direct contact with each other, and the control unit 62 determines that the control unit 62 is in FIG. The process proceeds to step S14.
On the other hand, when the boundary position A1 is not larger than the boundary position A2 (for example, when the boundary position A1 is 3 mm and the boundary position A2 is 4 mm), the active material on the right side in the traveling direction of the battery electrode sheet 2 This is a defective state in which the layer 30 and the current collector sheet 10 are in direct contact. In this case, the control means 62 proceeds to the process of step S12 in FIG.

  The control means 62 acquires the counter value C in step S12. The counter value C indicates the current inspection target location. The control means 62 detects the failure detected in the previous step 10 (failure in which the active material layer 30 on the right side in the traveling direction of the battery electrode sheet 2 and the current collector sheet 10 are in direct contact: failure mode M1). The acquired counter value C is stored in association with each other. Next, the control means 62 proceeds to the process of step S14 in FIG.

In the process of step S14, the control means 62 determines whether or not the boundary position B1 is smaller than the boundary position B2. When the boundary position B1 is smaller than the boundary position B2 (for example, when the boundary position B1 is −8 mm and the boundary position A2 is −5 mm), the left side in the traveling direction of the battery electrode sheet 2 (FIG. 5). It is determined that the active material layer 30 on the right side) and the current collector sheet 10 are not in direct contact with each other, and the control unit 62 proceeds to the process of step S18 in FIG.
On the other hand, when the boundary position B1 is not smaller than the boundary position B2 (for example, when the boundary position B1 is −5 mm and the boundary position A2 is −5 mm), the left side in the traveling direction of the battery electrode sheet 2 is The control unit 62 determines that the active material layer 30 and the current collector sheet 10 are in direct contact with each other and is in a defective state, and proceeds to the process of step S16 in FIG.

  The control means 62 acquires the counter value C in step S16. The counter value C indicates the current inspection target location. The control means 62 detects the failure detected in the previous step 14 (failure in which the left active material layer 30 and the current collector sheet 10 are in direct contact with each other in the traveling direction of the battery electrode sheet 2: failure mode M2). The acquired counter value C is stored in association with each other. Next, the control means 62 proceeds to the process of step S18 in FIG.

  In the process of step S18, the control means 62 calculates the width Z1 of the active material layer 30. The width Z1 can be calculated by the calculation formula [Z1 = T−A1 + B1]. For example, when the width T of the current collector sheet 10 is 100 mm, the boundary position A1 is 5 mm, and the boundary position B1 is −8 mm, the width Z1 = 100−5 + (− 8) = 87 (mm) It becomes.

Next, the control means 62 proceeds to the process of step S20 in FIG.
The control means 62 determines whether or not the width Z1 of the active material layer 30 is within the allowable range determined in step S1a. When the width Z1 is larger than Z1L and smaller than Z1H, it is determined that the width Z1 of the active material layer 30 is within the allowable range and is in a good state, and the process proceeds to step S24. If the width Z1 is outside the allowable range, it is determined that the state is defective, and the process proceeds to step S22.

  The control means 62 acquires the counter value C in step S22. The counter value C indicates the current inspection target location. The control means 62 stores the acquired counter value C in association with the failure detected in the previous step 20 (failure in which the width Z1 of the active material layer 30 is outside the allowable range: failure mode M3). Next, the control means 62 proceeds to the process of step S24 in FIG.

  In the process of step S24, the control means 62 calculates the width Z2 of the coating layer 20. The width Z2 can be calculated by the calculation formula [Z2 = T−A2 + B2]. For example, when the width T of the current collector sheet 10 is 100 mm, the boundary position A2 is 3 mm, and the boundary position B2 is −5 mm, the width Z2 = 100−3 + (− 5) = 92 (mm) It becomes.

Next, the control means 62 proceeds to the process of step S26 in FIG.
The control means 62 determines whether or not the width Z2 of the coating layer 20 is within the allowable range determined in step S1a. When the width Z2 is larger than Z2L and smaller than Z2H, it is determined that the width Z2 of the coating layer 20 is within the allowable range and is in a good state, and the process proceeds to step S30. If the width Z2 is outside the allowable range, it is determined that the state is defective and the process proceeds to step S28.

  The control means 62 acquires the counter value C in step S28. The counter value C indicates the current inspection target location. The control means 62 stores the acquired counter value C in association with the defect detected in the previous step 26 (defect in which the width Z2 of the coating layer 20 is outside the allowable range: defect mode M4). Next, the control means 62 proceeds to the process of step S30 in FIG.

Next, the control means 62 proceeds to the process of step S30 in FIG.
In the process of step S30, the control means 62 determines that the state is good unless the failure modes M1 to M4 exist. At this time, if feedback is required for the operation of the coating die 4, the control means 62 outputs a control signal to the coating control means 3. Further, as shown in FIG. 9, the control unit 62 stores the boundary positions A1, A2, B1, B2, the widths Z1, Z2, and the failure mode in the storage unit 63 in correspondence with the counter value C. If there is no failure, the failure mode is not stored.

Next, the control means 62 proceeds to the process of step S32 in FIG.
In step S32, the control means 62 counts up the counter value C.
Thereafter, the control means 62 returns to the processing of steps S2 and S4 and continues the inspection. The control means 62 performs an inspection operation when a stop signal of the inspection apparatus 1 is detected (for example, when a stop button of the inspection apparatus 1 is operated) or when it is detected that the battery electrode sheet 2 does not exist. Exit.

Below, with reference to FIG. 8 and FIG. 9, the state of the coating layer 20 and the active material layer 30 which were actually formed in the battery electrode sheet 2 is illustrated.
In the position corresponding to the counter value C = C1 shown in FIG. 8, it is determined in step S10 that the boundary position A1 is larger and better than the boundary position A2. In step S14, it is determined that the boundary position B1 is smaller than the boundary position B2 and is in a good state. In step S20, it is determined that the width Z1 of the active material layer 30 is within an allowable range. In step S26, it is determined that the width Z2 of the coating layer 20 is within the allowable range.
As shown in FIG. 9, in step S30, the storage means 63 stores the boundary positions A1, A2, B1, B2 and the widths Z1, Z2 in correspondence with the counter value C = C1. Since no failure was detected at the position of the counter value C = C1, no failure mode is stored.

In the position corresponding to the counter value C = C3 shown in FIG. 8, the boundary position A1 and the boundary position A2 are the same in step S12 described above, and it is determined that a failure in the failure mode M1 has occurred. In step S14, it is determined that the boundary position B1 is smaller than the boundary position B2 and is in a good state. In step S20, it is determined that the width Z1 of the active material layer 30 is within an allowable range. In step S26, it is determined that the width Z2 of the coating layer 20 is within the allowable range. At a position corresponding to the counter value C = C3, a failure mode M1 (a failure in which the active material layer 30 on the right side in the traveling direction is in direct contact with the current collector sheet 10) occurs.
As shown in FIG. 9, in step S30, the storage means 63 stores the boundary positions A1, A2, B1, B2, the widths Z1, Z2, and the failure mode M1 in correspondence with the counter value C = C3. In the process after the inspection, the battery electrode sheet 2 at the position corresponding to the counter value C = C3 is cut out and discarded.

In the position corresponding to the counter value C = C5 shown in FIG. 8, it is determined in step S10 that the boundary position A1 is larger and better than the boundary position A2. In step S16, it is determined that the boundary position B1 is larger than the boundary position B2 and a failure in the failure mode M2 has occurred. In step S20, it is determined that the width Z1 of the active material layer 30 is within an allowable range. In step S26, it is determined that the width Z2 of the coating layer 20 is within the allowable range. At a position corresponding to the counter value C = C5, a failure mode M2 (a failure in which the active material layer 30 on the left side in the traveling direction is in direct contact with the current collector sheet 10) occurs.
As shown in FIG. 9, in step S30, the storage means 63 stores the boundary positions A1, A2, B1, B2, the widths Z1, Z2, and the failure mode M2 in correspondence with the counter value C = C5. In the step after the inspection, the battery electrode sheet 2 at the position corresponding to the counter value C = C5 is cut out and discarded.

In the position corresponding to the counter value C = C12 shown in FIG. 8, the boundary position A1 and the boundary position A2 are the same in step S12 described above, and it is determined that the failure mode M1 has occurred. In step S14, it is determined that the boundary position B1 is smaller than the boundary position B2 and is in a good state. In step S22, it is determined that the width Z1 of the active material layer 30 is larger than the upper limit value Z1H of the width and a failure in the failure mode M3 has occurred. In step S26, it is determined that the width Z2 of the coating layer 20 is within an allowable range. At a position corresponding to the counter value C = C12, a failure mode M1 and a failure mode M3 are generated.
As shown in FIG. 9, in step S30, the storage means 63 corresponds to the counter value C = C12, the boundary positions A1, A2, B1, B2, the widths Z1, Z2, the failure mode M1, and the failure mode M3. Remember. In the step after the inspection, the battery electrode sheet 2 at the position corresponding to the counter value C = C12 is cut out and discarded.

In the position corresponding to the counter value C = C20 shown in FIG. 8, it is determined in step S10 that the boundary position A1 is larger and better than the boundary position A2. In step S14, it is determined that the boundary position B1 is smaller than the boundary position B2 and is in a good state. Further, in step S22, it is determined that the width Z1 of the active material layer 30 is smaller than the lower limit value Z1L of the width, and a failure in the failure mode M3 has occurred. In step S26, it is determined that the width Z2 of the coating layer 20 is within an allowable range. At a position corresponding to the counter value C = C20, a failure in the failure mode M3 occurs.
As shown in FIG. 9, in step S30, the storage means 63 stores the boundary positions A1, A2, B1, B2, the widths Z1, Z2, and the failure mode M3 in correspondence with the counter value C = C20. In the process after the inspection, the battery electrode sheet 2 at the position corresponding to the counter value C = C20 is cut out and discarded.

In the position corresponding to the counter value C = C23 shown in FIG. 8, it is determined in step S10 that the boundary position A1 is larger and better than the boundary position A2. In step S14, it is determined that the boundary position B1 is smaller than the boundary position B2 and is in a good state. In step S20, it is determined that the width Z1 of the active material layer 30 is within an allowable range. In step S28, it is determined that the width Z2 of the coating layer 20 is larger than the upper limit value Z2H of the width, and a failure in the failure mode M4 has occurred. At the position corresponding to the counter value C = C23, the failure mode M4 occurs.
As shown in FIG. 9, in step S30, the storage means 63 stores the boundary positions A1, A2, B1, B2, the widths Z1, Z2, and the failure mode M4 in correspondence with the counter value C = C23. In the process after the inspection, the battery electrode sheet 2 at the position corresponding to the counter value C = C23 is cut out and discarded.

In the position corresponding to the counter value C = C25 shown in FIG. 8, it is determined in step S10 that the boundary position A1 is larger and better than the boundary position A2. In step S16, the boundary position B1 and the boundary position B2 are the same, and it is determined that a failure in the failure mode M2 has occurred. In step S20, it is determined that the width Z1 of the active material layer 30 is within an allowable range. In step S <b> 28, it is determined that the width Z <b> 2 of the coating layer 20 is smaller than the lower limit value Z <b> 2 </ b> L of the width, and a failure in the failure mode M <b> 4 has occurred. At a position corresponding to the counter value C = C25, a failure in the failure mode M4 occurs.
As shown in FIG. 9, in step S30, the storage means 63 corresponds to the counter value C = C23, the boundary positions A1, A2, B1, B2, the widths Z1, Z2, the failure mode M2, and the failure mode M4. Remember. In the step after the inspection, the battery electrode sheet 2 at the position corresponding to the counter value C = C25 is cut out and discarded.

In the inspection apparatus 1 for the battery electrode sheet 2 of the present embodiment, the positions of the line width change points a2 and b2 where the line width of the captured laser beam L changes discontinuously and the position of the captured laser beam L are as follows. Based on the positions of the position change points a1 and b1 that change discontinuously, the boundary positions A2 and B2 between the current collector sheet 10 and the coating layer 20, and the boundary positions A1 and B1 between the coating layer 20 and the active material layer 30 Calculate
Since the coating layer 20 is a thin layer, the step at the boundary between the current collector sheet 10 and the coating layer 20 is small. For this reason, it is difficult to detect the boundary positions A2 and B2 based on the position change point (for example, by a light cutting method). On the other hand, the current collector sheet 10 and the coating layer 20 have a large difference in reflected light intensity of the laser light L. Therefore, the difference in the line width of the captured laser beam L is large. Based on the position of the line width change point, the boundary positions A2 and B2 between the current collector sheet 10 and the coating layer 20 can be calculated.
In addition, the active material layer 30 has a low reflected light intensity of the laser light L like the coating layer 20. The active material layer 30 and the coating layer 20 have a small difference in reflected light intensity of the laser light L. For this reason, it is difficult to detect the boundary positions A1 and B1 based on the position of the line width change point. On the other hand, since the active material layer 30 is a thick layer, a step at the boundary between the coating layer 20 and the active material layer 30 is large. Therefore, the boundary positions A1 and B1 can be calculated based on the position change points.
According to the inspection apparatus 1, there is a corresponding step between the surface of the coating and the surrounding surface (whether the coating for detecting the boundary position is thick to some extent), or between the coating surface and the surrounding surface. If there is a significant reflectance difference with respect to the irradiated laser beam L, the boundary position of the coating can be detected.

  It is also conceivable to calculate the boundary position of the film by a method of recognizing the color difference of the battery electrode sheet 2. When recognizing the color difference, the reflected light intensity in each component of RGB is detected. When the laser beam L is irradiated onto the battery electrode sheet 2 in order to specify the position change point, the luminance of the laser beam L is large. Therefore, the pixel of the image obtained by photographing the laser beam L is projected by the laser beam L. The portion S and the brightness S around it are saturated. For this reason, it is difficult to specify the position change point and the color change point from the same captured image. A position change point is specified from one shot image, and a color change point is specified from another shot image. The position change point and the color change point at the same position (position in the length direction of the battery electrode sheet 2) are synchronized in later processing. On the other hand, in order to specify the line width change point, it is only necessary to specify a pixel in a saturated state among pixels of an image obtained by photographing the laser beam L. For this reason, it is possible to simultaneously specify the position change point and the line width change point at the same position (position in the length direction of the battery electrode sheet 2) from the same captured image. The time required for inspection can be shortened.

The inspection apparatus 1 of the present embodiment can calculate the boundary position of the film even for the battery electrode sheet having a structure different from that of the battery electrode sheet 2 described in the above embodiment.
For example, FIG. 10 shows a configuration of the battery electrode sheet 2a. The battery electrode sheet 2a has a laminated structure of a current collector sheet 10a, a first coating 20a, and a second coating 30a. The current collector sheet 10a and the second coating 30a have low reflected light intensity when irradiated with the laser light L. The first coating 20a has a high reflected light intensity. The step at the boundary between the current collector sheet 10a and the first coating 20a is small. Moreover, the level | step difference of the boundary of the 1st film 20a and the 2nd film 30a is large. Therefore, the battery electrode sheet 2a onto which the laser beam L is projected is photographed as shown in FIG.
In this case, the boundary positions A2a and B2a between the current collector sheet 10a and the first coating 20a can be calculated by the first boundary calculation means 68 based on the position of the line width change point due to the reflected light intensity difference. . The boundary positions A1a and B1a between the first coating 20a and the second coating 30a can be calculated by the first boundary calculation means 68 based on the position of the line width change point. The boundary positions A1a and B1a can also be calculated by the second boundary calculation means 67 based on the position change point position.

FIG. 12 shows the configuration of the battery electrode sheet 2b. The battery electrode sheet 2b has a laminated structure of a current collector sheet 10b, a first coating 20b, and a second coating 30b. The first coating 20b has low reflected light intensity when irradiated with the laser light L. The current collector sheet 10b and the second coating 30b have high reflected light intensity. The step at the boundary between the current collector sheet 10b and the first coating 20b is small. Moreover, the level | step difference of the boundary of the 1st film 20b and the 2nd film 30b is large. Therefore, the battery electrode sheet 2b on which the laser beam L is projected is photographed as shown in FIG.
In this case, the boundary positions A2b and B2b between the current collector sheet 10b and the first coating 20b can be calculated by the first boundary calculation means 68 based on the position of the line width change point due to the reflected light intensity difference. . The boundary positions A1b and B1b between the first coating 20b and the second coating 30b can be calculated by the first boundary calculation means 68 based on the position of the line width change point. The boundary positions A1b and B1b can also be calculated by the second boundary calculation means 67 based on the position change point position.

FIG. 14 shows the configuration of the battery electrode sheet 2c. The battery electrode sheet 2c has a laminated structure of a current collector sheet 10c, a first coating 20c, and a second coating 30c. The current collector sheet 10c has low reflected light intensity when irradiated with the laser light L. The first coating 20c and the second coating 30c have high reflected light intensity. The step at the boundary between the current collector sheet 10c and the first coating 20c is small. Moreover, the level | step difference of the boundary of the 1st film 20c and the 2nd film 30c is large. Therefore, the battery electrode sheet 2c onto which the laser beam L is projected is photographed as shown in FIG.
In this case, the boundary positions A2c and B2c between the current collector sheet 10b and the first coating 20b can be calculated by the first boundary calculation means 68 based on the position of the line width change point due to the reflected light intensity difference. . The boundary positions A1c and B1c between the first film 20c and the second film 30c can be calculated by the second boundary calculation means 67 based on the position of the position change point.

(Modification of the first embodiment)
The inspection apparatus for the battery electrode sheet 2 includes laser light sources 41 and 42, CCD cameras 51 and 52, line width change point specifying means 65, first boundary calculation means 68, position change point specifying means 64, As long as the two-boundary calculating means 67 is provided, the inspection apparatus of the present invention is not limited to the configuration of the present embodiment.
For example, the inspection apparatus 1a illustrated in FIG. 16 includes a measurement apparatus 70 and a control apparatus 80 instead of the control apparatus 60 of the inspection apparatus 1 illustrated in FIG. In FIG. 16, the same components as those in the inspection apparatus 1 shown in FIG.

The measuring device 70 includes a measurement control means 72, an image memory 73, and an interface 71.
The measurement control means 72 is connected to the CCD cameras 51 and 52. The measurement control means 72 controls the conditions under which the CCD cameras 51 and 52 photograph the battery electrode sheet 2. In addition, information on the captured image captured by the CCD cameras 51 and 52 is stored in the image memory 73. When the measurement control unit 72 is requested to transmit image information from the control unit 82 of the control device 80, the measurement control unit 72 transmits the image information from the image memory 73 to the control device 80 via the interface 71.

The control device 80 includes control means 82, position change point specifying means 84, line width change point specifying means 85, second boundary calculation means 67, first boundary calculation means 68, storage means 83, and interface 81.
The control means 82 is connected to the coating control means 3. The control unit 62 transmits to the coating control unit 3 conditions relating to the application of the paste material by the coating die 4.
The control unit 82 requests the measurement apparatus 70 to transmit image information through the interface 81 at an appropriate timing.
The connection and operation of the control means 82, the position change point specifying means 64, the line width change point specifying means 65, the second boundary calculating means 67, the first boundary calculating means 68, and the storage means 63 are the same as the inspection apparatus described in FIG. Same as 1.
A communication line between the interface 71 and the interface 81 may be wired or wireless. Further, the communication line between the interface 81 and the coating control means 3 may be wired or wireless.
Since the control device 80 and the measurement device 70 have separate structures, the measurement device 70 can be installed at the site of the coating process of the active material layer 30, and the control device 80 can be installed in an office or the like.

The apparatus for detecting the boundary position of the coating film formed on the surface of the object to be measured of the present invention has any configuration as illustrated in the configuration of the inspection apparatus 1 in FIG. 2 or the configuration of the inspection apparatus 1a in FIG. The elements may be formed integrally.
In the present embodiment, the case where the position change point specifying unit 64, the line width change point specifying unit 65, the second boundary calculating unit 67, and the first boundary calculating unit 68 are steps of a program executed by the control unit 62 has been described. However, at least one means may be executed by another hardware.

(Example 2)
In FIG. 17, the test | inspection apparatus 1b of the sheet | seat 2 for battery electrodes of a present Example is typically shown. In FIG. 17, the same components as those in the inspection apparatus 1 shown in FIG.
The control device 60b of the inspection apparatus 1b includes color change point specifying means 92 (an example of third specifying means) instead of the line width change point specifying means 65 of the control device 60 shown in FIG. Further, the control device 60 b includes third boundary calculation means 94 instead of the first boundary calculation means 68 of the control device 60.
Here, the current collector sheet 10 is formed using a metal foil and has a white color. On the other hand, the coating layer 20 and the active material layer 30 contain conductive carbon and have a black color.
The control means 62 instructs the color change point specifying means 92 to specify the color change point at which the color of the photographed battery electrode sheet 2 changes discontinuously from the photographed images photographed by the CCD cameras 51 and 52. To do. In the battery electrode sheet 2 of the present embodiment, the current collector sheet 10 and the coating layer 20 are not similar in color, and the color greatly changes discontinuously at the boundary. Further, the coating layer 20 and the active material layer 30 are similar in color, and the color change at the boundary is small. Therefore, the color change point is at the same position as the line width change points a2 and b2 shown in FIG. Hereinafter, the color change points specified by the color change point specifying unit 92 are referred to as color change points a2 and b2.
The control means 62 applies the current collector sheet 10 and the coating to the third boundary calculation means 94 from the positions of the color change points a2 and b2 specified by the color change point specifying means 92 (positions in the width direction of the battery electrode sheet 2). The boundary positions A2 and B2 (see FIG. 5) with the layer 20 are calculated.
The boundary positions A1 and A2 between the coating layer 20 and the active material layer 30 can be calculated by the position change point specifying means 64 and the second boundary calculating means 67, as in the inspection apparatus 1 of the first embodiment.

In the inspection apparatus 1a for the battery electrode sheet 2 of the present embodiment, the positions of the color change points a2 and b2 where the color of the captured laser light L changes discontinuously and the position of the captured laser light L are discontinuous. The boundary positions A2 and B2 between the current collector sheet 10 and the coating layer 20 and the boundary positions A1 and B1 between the coating layer 20 and the active material layer 30 are calculated based on the positions of the position change points a1 and b1 that change to To do.
Since the coating layer 20 is a thin layer, the step at the boundary between the current collector sheet 10 and the coating layer 20 is small. For this reason, it is difficult to detect the boundary positions A2 and B2 based on the position change point (for example, by a light cutting method). On the other hand, the current collector sheet 10 and the coating layer 20 have a large color difference. Therefore, the boundary positions A2 and B2 between the current collector sheet 10 and the coating layer 20 can be calculated based on the position of the color change point.
Further, the active material layer 30 has little color difference from the coating layer 20. For this reason, it is difficult to detect the boundary positions A1 and B1 based on the position of the color change point. On the other hand, since the active material layer 30 is a thick layer, a step at the boundary between the coating layer 20 and the active material layer 30 is large. Therefore, the boundary positions A1 and B1 can be calculated based on the position change points.
According to the inspection apparatus 1, if the difference between the upper layer and the lower layer of the boundary position is large, or if there is a color difference between the upper layer and the lower layer of the boundary position, the boundary position can be calculated.

  In the first embodiment and the second embodiment, the case where the battery electrode sheet 2 to be inspected by the inspection devices 1 and 1a has a laminated structure of the current collector sheet 10, the coating layer 20, and the active material layer 30 will be described. did. It is sufficient that at least one film is formed on the surface of the measurement object. For example, when the reflected light intensity of the laser light L on the surface of the coating 30d is weak and the reflected light intensity of the laser light L on the surface of the current collector sheet 10d is strong like the battery electrode sheet 2d shown in FIG. Even if the step between the coating 30d and the current collector sheet 10d is small, the boundary positions A2 and B2 can be calculated by specifying the line width change point.

1st Example demonstrated the case where the test | inspection apparatus 1 calculates the boundary position of the film currently formed in the sheet | seat 2 for battery electrodes based on a position change point and a line | wire width change point. Moreover, 2nd Example demonstrated the case where the inspection apparatus 1b calculated the boundary position of the film currently formed in the battery electrode sheet 2 based on a position change point and a color change point. The inspection apparatus may calculate the boundary position of the film formed on the battery electrode sheet 2 based on the position change point, the line width change point, and the color change point. In this case, there is a corresponding step between the surface of the coating and the surrounding surface (whether the coating for detecting the boundary position is thick to some extent), or a significant reflectivity for the irradiated laser beam L. If there is a difference or there is a color difference, the boundary position of the film can be detected.
Moreover, the inspection apparatus of this invention may calculate the boundary position of the film currently formed in the battery electrode sheet | seat 2 only based on a line | wire width change point. Even with this inspection device, the boundary position of the coating formed on the battery electrode sheet 2 can be calculated even if the coating is thin.

  In the first example and the second example, the case of inspecting the battery electrode sheet 2 in which the film is formed on one surface of the current collector sheet 10 has been described. The inspection apparatus of the present invention can also inspect the battery electrode sheet 2 in which a film is formed on both surfaces of the current collector sheet 10. The inspected boundary positions A1, B1, A2, B2, the width Z1 of the active material layer, and the width Z2 of the coating layer 20 are stored in the storage unit 63. When inspecting the film formed on the other surface, it is also possible to detect the presence or absence of positional deviation from the film formed on the one surface.

  In the step of applying the active material paste to the battery electrode sheet 2, a plurality of rows of active material pastes may be applied on the current collector sheet 10. In a later step, the rows are cut to form the battery electrode sheets 2 one by one. In this case, in the step of applying the active material paste, that is, when the boundary of the coating is detected by the inspection apparatus, the laser light source and the CCD camera corresponding to the number of rows (the number of the battery electrode sheets 2) are further provided. It is preferable that it is.

  In the first embodiment and the second embodiment, the case where the apparatus of the present invention detects the boundary of the coating formed on the surface of the battery electrode sheet 2 is described. However, the apparatus of the present invention is other than the battery electrode sheet 2. The boundary of the film formed on the surface of the film can also be detected. According to the apparatus of the present invention, the boundary position of the film formed on the measurement object can be calculated even if the film is thin.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

The structure of the sheet | seat 2 for battery electrodes is shown. 2 is a block diagram schematically showing the configuration of the inspection apparatus 1. FIG. 3 is a top view of the battery electrode sheet 2 showing positions where laser light sources 41 and 42 and CCD cameras 51 and 52 are disposed. FIG. It is a flowchart of the program which the control means 62 performs in order to test | inspect the battery electrode sheet | seat 2. FIG. Photographed images E1 and E2 of the surface of the battery electrode sheet 2 onto which the laser light L is projected are shown. It is a figure explaining that the position (position of the length direction of sheet 2 for battery electrodes) of the photographed laser beam L changes discontinuously. In the laser light L photographed in the photographed images E1 and E2, the distribution of the luminance S in the line width direction P is shown. The battery electrode sheet 2 in which a defect is determined by the inspection device 1 is shown. The examination results stored in the storage means 63 are shown. The structure of the battery electrode sheet 2a is shown. The picked-up image of the surface of the sheet | seat 2a for battery electrodes on which the laser beam L is projected is shown. The structure of the battery electrode sheet 2b is shown. The picked-up image of the surface of the battery electrode sheet 2b on which the laser beam L is projected is shown. The structure of the battery electrode sheet 2c is shown. The picked-up image of the surface of the battery electrode sheet 2c on which the laser beam L is projected is shown. It is a block diagram which shows typically the structure of the inspection apparatus 1a. It is a block diagram which shows typically the structure of the inspection apparatus 1b. The structure of the battery electrode sheet 2d is shown. A photographed image of the surface of the battery electrode sheet 2d onto which the laser beam L is projected is shown. It is a figure explaining the optical cutting method of a prior art. A photographed image of the surface of the battery electrode sheet 102 onto which the laser beam L is projected is shown.

Explanation of symbols

1: inspection devices 1, 1a, 1b: inspection devices 2, 2a, 2b, 2c, 2d: battery electrode sheet 3: coating control means 4: coating die 5: coating rollers 10, 10a, 10b, 10c, 10d: current collector sheet 20: coating layer 20a, 20b, 20c, 30a, 30b, 30c, 30d: coating 30: active material layer 41, 42: laser light source 51, 52: camera 60, 60b: controller 62, 82 : Control means 63, 83: storage means 64, 84: position change point specifying means 65, 85: line width change point specifying means 67: second boundary calculating means 68: first boundary calculating means 70: measuring devices 71, 81: Interface 72: Measurement control means 73: Image memory 80: Control device 92: Color change point specifying means 94: Third boundary calculation means A1, A2, B1, B2: Boundary positions a1, b1: Position change points a2, 2: line width change points, the color change point C: counter value E1, E2: photographed image L: laser light T, Z1, Z2: width

Claims (3)

It is a device that detects the boundary of the film formed on the surface of the measurement object,
An irradiation means for irradiating the surface of the measurement object with slit light;
Photographing means for photographing the surface of the measurement object onto which the slit light is projected;
A first specifying means for specifying a line width change point at which the line width of the captured slit light changes discontinuously from a photographed image by the photographing means;
First boundary calculation means for calculating the boundary position of the film formed on the surface of the measurement object from the position of the line width change point in the identified captured image;
A device comprising: Second specifying means for specifying a position change point at which the position of the captured slit light changes discontinuously from the image captured by the imaging means;
A second boundary calculating means for calculating the boundary position of the film formed on the surface of the measurement object from the position of the position change point in the identified captured image;
The apparatus according to claim 1, wherein the irradiating unit irradiates slit light obliquely to the surface of the measurement object. A third specifying means for specifying a color change point at which the color of the surface of the measured measurement object discontinuously changes from a photographed image by the photographing means;
Third boundary calculation means for calculating the boundary position of the film formed on the surface of the measurement object from the position of the color change point in the identified captured image;
The apparatus according to claim 1, further comprising:

Images