Inspection device and inspection method

Abstract

An inspection device 65 is for inspecting the depths of a plurality of bottomed holes 103 formed in a processed surface of an electrode plate 100, and comprises: a light source 73 for irradiating, with inspection light, the processed surface in which the holes 103 are formed; a detection part 83 for detecting the inspection light reflected on the processed surface; and a control part 90 for obtaining a first index indicating the intensity of the inspection light detected by the detection part 83, and for evaluating the depths of the holes 103 on the basis of the relationship between the depths of the holes 103 and the first index.

Description

Inspection device and inspection method

[0001] The technologies disclosed herein belong to the technical field of inspection apparatus and inspection methods.

[0002] If there are scratches, foreign matter, or irregularities on the surface of the electrode plates used in batteries, the performance of the battery will decrease. On the other hand, the more uniform the surface of the electrode plates, the longer-lasting and higher-performance batteries can be manufactured. Therefore, inspecting the surface of the electrode plates is important for ensuring the quality of batteries and improving their performance. Devices for inspecting the condition of such electrode plate surfaces have existed for a long time. For example, the inspection device described in Patent Document 1 confirms the condition of the electrode plate surface by photographing the surface of the electrode plate.

[0003] Special Publication No. 2024-521362

[0004] Incidentally, in energy storage devices such as lithium-ion batteries, lithium-ion capacitors, and all-solid-state batteries, a number of holes are sometimes formed in the active material layer constituting the electrode in order to promote the penetration of the electrolyte into the electrode.

[0005] Such holes are formed using a device that, for example, rolls a roller with multiple protrusions on its outer circumference over the active material. Therefore, depending on the condition of the protrusions and the degree to which the roller presses against the electrode plate, there is a risk that the multiple holes formed on the electrode plate may be unevenly formed.

[0006] However, evaluating the depth of multiple holes in an electrode plate has not been considered until now. Even if the inspection device described in prior art 1 were used to evaluate the depth of the holes, precise evaluation would not be possible because the holes are so small. The purpose of this disclosure is to provide a simple and precise way to evaluate the depth of multiple holes formed on the machined surface of an electrode plate.

[0007] In order to solve the problem described above, in the technology disclosed herein, an inspection apparatus for inspecting the depth of a plurality of bottomed holes formed in a processed surface of an electrode plate comprises: a light source that irradiates inspection light toward the processed surface in which the holes are formed; a detection unit that detects the inspection light reflected by the processed surface; and a control unit that obtains a first index indicating an intensity of the inspection light detected by the detection unit, and evaluates the depth of the holes based on a relationship between the depth of the holes and the first index.

[0008] According to this configuration, the depth of the holes formed in the electrode plate can be evaluated only by detecting the reflection intensity of the inspection light irradiated onto the processed surface of the electrode plate. Thus, the holes can be evaluated more easily compared to a method in which, for example, the holes are photographed and the image data thereof is analyzed. Further, when there are a large number of holes, the work burden on an operator can be reduced.

[0009] In one embodiment, the plurality of holes may be formed on the processed surface when the electrode plate is fed in a traveling direction and comes into contact with protrusions formed on an outer peripheral surface of a processing roller that rotates in the traveling direction, the light source may irradiate the inspection light onto the moving electrode plate for a predetermined period, and the detection unit may continuously detect the inspection light reflected by the processed surface.

[0010] According to this configuration, when holes are continuously formed in the electrode plate fed in the traveling direction, the depth of the plurality of holes flowing in the traveling direction can be sequentially evaluated. This makes it possible to grasp the depth of the holes formed by the processing roller in real time. In addition, by continuously evaluating the depths of the holes, it is possible to grasp the tendency of the depths of the sequentially formed holes. Accordingly, for example, when it is recognized that the depth of the sequentially formed holes gradually becomes shallower, it can be grasped that the protrusions of the processing roller are also gradually worn.

[0011] In one embodiment, the light source includes a first light source and a second light source, the detection unit includes a first detection unit and a second detection unit, the first detection unit detects inspection light emitted from the first light source, the second detection unit detects inspection light emitted from the second light source, and the first light source and the second light source are each arranged to irradiate different positions on the fed electrode plate. This configuration is also acceptable.

[0012] According to this configuration, it is possible to evaluate whether holes are normally formed at the respective positions irradiated by the first light source and the second light source. For example, when the first light source and the second light source are arranged to irradiate different positions in the width direction of the electrode plate, if the measured depths of the holes are different from each other, it can be detected that the electrode plate is not in uniform contact with the surface of the processing roller. This makes it possible to recognize, for example, that the axis of the processing roller is misaligned relative to the processing surface of the electrode plate, or that the pressing force of the protrusions of the processing roller against the electrode plate is inappropriate.

[0013] In one embodiment, the electrode plate is guided in the traveling direction by a first roller disposed downstream of the processing roller, and the light source irradiates the inspection light onto an irradiation region where the electrode plate contacts an outer peripheral surface of the first roller. This configuration is also acceptable.

[0014] According to this configuration, the portion of the electrode plate that is not in contact with the first roller is in a suspended state, and is prone to vertical vibration (wobble) during movement, making it unstable. Irradiating such a portion with inspection light may cause variation in the value of the first index. On the other hand, in the portion where the electrode plate is in contact with the first roller, the surface of the electrode plate is supported by the first roller, so vibration (wobble) is relatively small. Irradiating such a portion with inspection light enables stable acquisition of the first index.

[0015] In one embodiment, the first index is voltage or reflection intensity. According to this configuration, reflection intensity can be grasped using voltage as an index.

[0016] In one embodiment, the control unit may determine that the depth of the hole is normal when the first indicator is within a first range, and the first range may be a range of values ​​for the first indicator that corresponds to within ±5 to 10% of the reference value of the depth of the hole.

[0017] This configuration allows for the detection of abnormalities in the depth of holes formed in the electrode plate.

[0018] In one embodiment, there is an inspection method for inspecting the depth of a plurality of bottomed holes formed on a machined surface of an electrode plate, which may include the steps of: determining a first index indicating the intensity of reflected light from an inspection light irradiated toward the machined surface on which the holes are formed; and evaluating the depth of the holes based on the relationship between the depth of the holes and the first index.

[0019] As described above, the technology disclosed herein provides an inspection device that can easily evaluate the depth of holes formed in an electrode plate.

[0020] Figure 1A is a plan view of the electrode plate after processing according to this embodiment. Figure 1B is a cross-sectional view of the electrode plate cut along the plane corresponding to the line Ib-Ib in Figure 1A. Figure 2 is a schematic diagram showing the configuration of the electrode plate processing apparatus and inspection apparatus. Figure 3 is a front view of the mold apparatus including the processing rollers. Figure 4 is a side view of the mold apparatus. Figure 5 is an exploded perspective view of the processing rollers. Figure 6 is a plan view showing the arrangement of the processing rollers. Figure 7 is a side view showing the positional relationship between the processing rollers and the backup rollers. Figure 8 is a schematic diagram showing the arrangement of the irradiation device and light receiving device when the processing surface is viewed from above. Figure 9 is a diagram showing the arrangement of the irradiation device and light receiving device when the processing surface is viewed from the width direction. Figure 10 is a block diagram showing the relationship between the control unit and various devices. Figure 11 is a graph showing the relationship between the first indicator and the depth of the hole. Figure 12 is a flowchart showing an example of an inspection method.

[0021] The following describes exemplary embodiments in detail with reference to the drawings.

[0022] (1) Electrode Plate Figures 1A and 1B show an electrode plate 100 processed by the electrode plate processing apparatus 1 according to this embodiment. This electrode plate 100 is an electrode plate used for at least one of the positive electrode and negative electrode of a secondary battery such as a lithium-ion battery.

[0023] As shown in Figure 1B, the electrode plate 100 is constructed by laminating an active material layer 101 onto a current collector foil 102. In the case of a lithium-ion battery, the active material layer 101 of the positive electrode is made of manganese lithium composite oxide (LiMn ２ O ４ ) and nickel-manganese based LiNi ｘ Mn １－ｘ O ２ A lithium-containing composite oxide containing lithium (0 < x < 1) and at least one transition metal element is used, and the active material layer 101 of the negative electrode is made of carbon material such as carbon particles. The current collector foil 102 can be made of aluminum or an aluminum-based alloy if it is the positive electrode, or copper or a copper-based alloy if it is the negative electrode.

[0024] Multiple bottomed holes 103 are formed on the processed surface of the electrode plate 100. The processed surface of the electrode plate 100 corresponds to the side of the electrode plate 100 on which the active material layer 101 is formed. That is, the multiple bottomed holes 103 are provided in the active material layer 101 of the electrode plate 100. The holes 103 improve the penetration efficiency of the electrolyte into the active material layer 101. In this embodiment, the holes 103 are inverted cone-shaped. The depth of the holes 103 is, for example, about 10 μm. The electrode plate 100 is a wide thin plate when processed, but after processing, it is cut to an appropriate size according to the shape of the battery, resulting in the shape shown in Figures 1A and 1B.

[0025] (2) Electrode Plate Processing Apparatus The electrode plate processing apparatus 1 shown in Figure 2 (hereinafter simply referred to as processing apparatus 1) comprises: an unwinding roller 10 around which the electrode plate 100 before processing is wound and which feeds the electrode plate 100 in the direction of travel; a first guide roller 11 which guides the electrode plate 100 fed from the unwinding roller 10 in the direction of travel; a first dancer section 12 for adjusting the tension applied to the electrode plate 100 before processing during transport; a second guide roller 13 which guides the electrode plate 100 sent from the first dancer section 12 to a processing mechanism 30 located downstream in the direction of travel; a processing mechanism 30 which forms a hole 103 in the processed surface (the surface on which the active material layer 101 is formed) of the electrode plate 100; a second dancer section 14 for adjusting the tension applied to the electrode plate 100 after processing during transport; third and fourth guide rollers 15 and 16 which guide the electrode plate 100 after processing to a winding roller 20; and a winding roller 20 which winds up the electrode plate 100 after processing. The direction of travel indicates the direction in which the electrode plate 100 is transported from the feed roller 10 to the winding roller 20 (the straight arrow shown in Figure 2). The direction of travel is the longitudinal direction of the electrode plate 100 wound onto the winding roller 10.

[0026] The unwinding roller 10 is configured as a drive roller that is rotationally driven by the first motor 10a. In the processing apparatus 1 shown in Figure 2, the electrode plate 100 is wound around the unwinding roller 10 such that the active material layer 101 of the electrode plate 100 is on the back side. Although not shown in the figure, a winding diameter sensor is provided near the unwinding roller 10 to detect the winding diameter of the electrode plate 100 wound around the unwinding roller 10.

[0027] The first guide roller 11 guides the electrode plate 100, which has been fed out from the unwinding roller 10, to the first dancer section 12 located downstream. The first guide roller 11 is a free roller that does not have a drive source for rotation.

[0028] The first dancer section 12 includes a fixed-position first support roller 12a, a first dancing roller 12b positioned downstream of the first support roller 12a and configured to be able to move in the vertical direction, and a first oscillating mechanism 12c that oscillates the first dancing roller 12b.

[0029] The first oscillating mechanism 12c includes a first connecting rod, one end of which is connected to the first dancing roller 12b and the other end of which is attached to a support shaft, and a first dancer cylinder 12d that oscillates the first connecting rod around the support shaft.

[0030] The electrode plate 100 is wound around the first support roller 12a and then around the first dancing roller 12b. The first dancer unit 12 adjusts the tension on the electrode plate 100 to be constant by having the first dancer cylinder 12d push and pull the first connecting rod, causing the first dancing roller 12b to move relative to the first support roller 12a.

[0031] The first support roller 12a and the first dancing roller 12b are both composed of free rollers that do not have a drive source for rotation. The first dancer cylinder 12d is composed of an air cylinder.

[0032] Although not shown in the diagram, an EPC (Edge Position Control, registered trademark) sensor for detecting the position of the widthwise edge of the electrode plate 100 being transported is provided between the first guide roller 11 and the first support roller 12a, and a tension sensor for detecting the tension of the electrode plate 100 during transport is provided on the first support roller 12a.

[0033] The second guide roller 13 guides the electrode plate 100 to the processing mechanism 30 located downstream. The second guide roller 13 is positioned so that the electrode plate 100 can wrap around the backup roller 40 of the processing mechanism 30 by at least one-third of its circumference. The second guide roller 13 is a free roller that does not have a drive source for rotation.

[0034] The processing mechanism 30 includes a plurality of mold devices 31, each having a processing roller 32 that forms a hole 103 on the processed surface of the electrode plate 100, and a backup roller 40 that holds the electrode plate 100 together with each processing roller 32. Each mold device 31 has a mold pressurizing cylinder 38 (see Figure 3, etc.) that presses the processing roller 32 toward the backup roller 40. The backup roller 40 is configured as a drive motor that is rotationally driven by a third motor 42. Details of the processing mechanism 30 will be described later.

[0035] The second dancer section 14 includes a second support roller 14a that is fixed in position, a second dancing roller 14b that is located upstream of the second support roller 14a and is configured to be able to change position, and a second oscillating mechanism 14c that oscillates the second dancing roller 14b.

[0036] The second rocking mechanism 14c includes a second connecting rod, one end of which is connected to the second dancing roller 14b and the other end of which is attached to a support shaft, and a second dancer cylinder 14d that rocks the second connecting rod around the support shaft.

[0037] The electrode plate 100 is wound around the second dancing roller 14b and then around the second support roller 14a. The second dancer unit 14 adjusts the tension on the electrode plate 100 to be constant by having the second dancer cylinder 14d push and pull the second connecting rod, causing the second dancing roller 14b to move relative to the second support roller 14a.

[0038] The second support roller 14a and the second dancing roller 14b are both free rollers that do not have a drive source for rotation. The second dancer cylinder 14d is an air cylinder. Although not shown in the figure, the second support roller 14a is equipped with a tension sensor that detects the tension of the electrode plate 100 during transport.

[0039] The third and fourth guide rollers 15 and 16 are positioned downstream of the processing roller 32. In other words, the third and fourth guide rollers 15 and 16 are positioned downstream of the backup roller 40. The third and fourth guide rollers 15 and 16 guide the processed electrode plate 100 in the direction of travel. The third and fourth guide rollers 15 and 16 are composed of free rollers that do not have a drive source for rotation. Although not shown in the figures, an EPC (Edge Position Control, registered trademark) sensor is provided between the second support roller 14a and the third guide roller 15 to detect the position of the widthwise edge of the conveyed electrode plate 100. The third guide roller 15 is an example of the first roller of this disclosure.

[0040] The winding roller 20 is configured as a drive roller that is rotationally driven by the second motor 20a. In the processing apparatus 1 shown in Figure 2, the electrode plate 100 is wound around the winding roller 20 such that the active material layer 101 of the electrode plate 100 faces outwards. Although not shown in the figure, a winding diameter sensor is provided near the winding roller 20 to detect the winding diameter of the electrode plate 100 wound around the winding roller 20.

[0041] The processing apparatus 1 is operated and controlled by a controller unit 50. The controller unit 50 has a processor with a CPU, a memory containing multiple modules, etc. Based on the detection results of each winding diameter sensor, each tension sensor, each EPC sensor, and each load sensor 38b described later, the controller unit 50 operates the first motor 10a, the second motor 20a, the third motor 42, the first dancer cylinder 12d, the second dancer cylinder 14d, and the mold pressurizing cylinder 38 (see Figure 3, etc.).

[0042] Specifically, the controller unit 50 synchronizes the first motor 10a, the second motor 20a, and the third motor 42, and adjusts the amount of air supplied to the first dancer cylinder 12d and the second dancer cylinder 14d, based on the detection results of each sensor, so that the electrode plate 100 does not bend or meander while being transported.

[0043] Furthermore, the controller unit 50 controls the amount of air supplied to each mold pressurizing cylinder 38 so that the pressing force of each processing roller 32 against the electrode plate 100 remains constant. This function is stored as software in a memory module.

[0044] (3) Mold devices Figures 3 to 5 show mold devices 31 provided in the processing mechanism 30. There are multiple mold devices 31 (six in this embodiment), but since the configuration of each mold device 31 is the same, only one mold device 31 will be described in detail below.

[0045] As shown in Figures 3 and 4, the mold apparatus 31 has a processing roller 32 as a mold for forming holes 103 on the processed surface of the electrode plate 100. The width of the processing roller 32 is narrower than the width of the electrode plate 100. Specifically, in this embodiment, the width of the processing roller 32 is about 1 / 6 of the width of the electrode plate 100 during processing.

[0046] (3-1) Processing Roller The processing roller 32 has a cylindrical roller body 32a, as shown in Figure 5. The processing roller 32 is formed by attaching a single metal plate 33 to the outer surface of the roller body 32a with adhesive. The width of the metal plate 33 is the same as the width of the roller body 32a, and the length of the metal plate 33 is the same as the circumference of the roller body 32a. The through hole 32b of the roller body 32a is the part into which the support shaft 35, which will be described later, is inserted. The roller body 32a can be made of metal such as aluminum or stainless steel.

[0047] Multiple protrusions 33a are formed on the outer circumferential surface of the processing roller 32. Each protrusion 33a forms a hole 103 on the processing surface of the electrode plate 100 that is in contact with the outer circumferential surface of the processing roller 32. Specifically, the multiple protrusions 33a are formed in a predetermined pattern on the workpiece surface 33b of the metal plate 33. The workpiece surface 33b is the surface opposite to the surface in contact with the roller body 32a. The protrusions 33a are conical in shape, corresponding to the shape of the hole 103. The height of the protrusions 33a from the workpiece surface 33b is set to about 10 μm, depending on the depth of the hole 103. Each protrusion 33a is arranged at equal intervals in the width direction of the metal plate 33. The protrusions 33a are made of a metal harder than the active material layer 101.

[0048] The processing roller 32 is a free roller that does not have a drive source for rotation. The processing roller 32 rotates in the direction of travel while the electrode plate 100 is being fed out by the unwinding roller 10. In this way, the multiple holes 103 formed on the processed surface of the electrode plate 100 are formed by contact with the protrusions 33a formed on the outer circumferential surface of the processing roller that rotates in the direction of travel.

[0049] Let n be the number of protrusions arranged in a single row in the axial direction of each processing roller 32. As the processing roller 32 rotates, n holes are sequentially formed in the width direction of the processed surface for each processing roller. Also, as the processing roller 32 rotates, n rows of holes are formed in the width direction for each processing roller when viewed from the direction of travel (see Figure 1A).

[0050] (3-2) Support mechanism The mold device 31 has a support mechanism that supports the processing rollers 32. One support mechanism is provided for each mold device 31, and each supports each processing roller 32 independently. The support mechanism has a support shaft 35 that is fixed to the processing roller 32 and supports the processing roller 32, and a holding part 36 that holds the processing roller 32 together with the support shaft 35.

[0051] The support shaft 35 is attached and fixed to the machining roller 32 so as to be coaxial with the machining roller 32. Bearings 37 are attached to both axial ends of the support shaft 35. This allows the machining roller 32 to rotate together with the support shaft 35 around its central axis.

[0052] As shown in Figure 3, the retaining portion 36 has a U-shape when viewed from the front. Specifically, the retaining portion 36 has a first wall portion 36a that is located on one side in the axial direction of the support shaft 35 and has a rectangular plate shape, a second wall portion 36b that is located on the other side in the axial direction opposite to the first wall portion 36a and has a rectangular plate shape, and a connecting wall portion 36c that connects one end of the first wall portion 36a in the longitudinal direction and one end of the second wall portion 36b in the longitudinal direction in the axial direction. Recesses for housing and fixing the bearing 37 are formed in the other side of the longitudinal direction of the first wall portion 36a and the second wall portion 36b (only the recess of the first wall portion 36a is shown in Figure 4). A long, narrow plate-shaped cover 36d is placed in the opening of the recess. The cover 36d is fixed to the first wall portion 36a and the second wall portion 36b by bolts, respectively. Furthermore, the first wall portion 36a, the second wall portion 36b, and the connecting wall portion 36c may be an integral part or may be composed of separate parts.

[0053] (3-3) The mold pressurizing cylinder 38 of the pressurizing cylinder mold device 31 has the tip of its cylinder rod 38a connected to the connecting wall portion 36c of the holding portion 36, and moves the processing roller 32 together with the holding portion 36 in the axial direction of the cylinder rod 38a. The cylinder rod 38a of the mold pressurizing cylinder 38 is positioned such that the central axis C1 of the processing roller 32 (coinciding with the center of the support shaft 35) is located on the extension line L of the axis line.

[0054] The mold pressurizing cylinder 38 is made of air. The mold pressurizing cylinder 38 is connected to an air supply source (not shown) via an air supply passage 61. The air supply passage 61 is provided with a regulator 62 for adjusting the amount of air supplied to the mold pressurizing cylinder 38.

[0055] The regulator 62 is controlled by the controller unit 50, which controls the regulator 62 to adjust the amount of air supplied to the mold pressurizing cylinder 38. This adjusts the pressing force applied by the processing roller 32 to the electrode plate 100 wrapped around the backup roller 40 to remain constant. "Constant pressing force" does not mean that it must be strictly constant; it may be increased or decreased slightly as long as the pressing force is sufficient to press the workpiece surface 33b of the metal plate 33 of the processing roller 32 against the active material layer 101 of the electrode plate 100, and the pressing force does not compress or deform the active material layer 101 (excluding deformation due to hole processing).

[0056] The mold pressurizing cylinder 38 has a load sensor 38b for detecting the pressing force of the processing roller 32 against the electrode plate 100. The load sensor 38b is, for example, built into the cylinder rod 38a and detects the load applied to the cylinder rod 38a via the processing roller 32, support shaft 35, and holding part 36. The controller unit 50 controls the regulator 62 based on the detection result of the load sensor 38b.

[0057] The mold device 31 has a rail 39 as a guide when the processing roller 32 is moved back and forth by the mold pressing cylinder 38. The rail 39 extends parallel to the axis of the cylinder rod 38a. The rail 39 engages with the connecting wall portion 36c of the holding portion 36. As a result, the processing roller 32 moves so that the trajectory of its center is parallel to the rail 39.

[0058] (3-4) Backup Roller As shown in Figure 6, the backup roller 40 consists of a single roller with a width wider than the width of the electrode plate 100. The backup roller 40 is fixed to the frame 2 of the processing apparatus 1 via a support shaft 41. The support shaft 41 is connected to a third motor 42. The support shaft 41 is rotated by the third motor 42, causing the backup roller 40 to rotate around its central axis.

[0059] As shown in Figures 2 and 7, the electrode plate 100 is wound around the backup roller 40 for more than one-third of its circumference. The axial direction of the backup roller 40 coincides with the width direction of the wound electrode plate 100. The backup roller 40 is, for example, a metal roller.

[0060] (3-5) Arrangement of mold devices and backup rollers Next, the arrangement of each mold device 31 and backup roller 40 will be described with reference to Figures 6 and 7. Note that in Figure 6, the support structure of each mold device 31 to the frame 2 has been omitted for the sake of simplifying the diagram.

[0061] Each mold device 31 is arranged such that each processing roller 32 is aligned in the width direction of the electrode plate 100 when viewed from the circumferential direction of the backup roller 40, and that adjacent processing rollers 32 in the width direction are offset from each other in the circumferential direction of the backup roller 40.

[0062] Specifically, each mold device 31 is arranged such that each processing roller 32 is arranged in a staggered pattern in the width direction of the electrode plate 100 when viewed from the radial direction of the backup roller 40. More specifically, when each mold device 31 is designated as the first mold device 311, the second mold device 312, the third mold device 313, the fourth mold device 314, the fifth mold device 315, and the sixth mold device 316, in order from one end (here, the side where the third motor 42 is located) in the axial direction of the backup roller 40 (hereinafter referred to as the backup axial direction), the first mold device 311, the third mold device 313, and the fifth mold device 315 are positioned at a first position in the circumferential direction of the backup roller 40, at equal intervals in the backup axial direction, while the second mold device 312, the fourth mold device 314, and the sixth mold device 316 are positioned at a second position different from the first position in the circumferential direction of the backup roller 40, at equal intervals in the backup axial direction. The second mold device 312 is located between the first mold device 311 and the third mold device 313 in the backup axial direction. The fourth mold device 314 is located between the third mold device 313 and the fifth mold device 315 in the backup axial direction. The sixth mold device 316 is located on the other side of the backup axial direction from the fifth mold device 315.

[0063] The first mold device 311 and the second mold device 312 are arranged such that the distance in the backup axis direction between the projection 33a on the other side in the backup axis direction of the processing roller 32 of the first mold device 311 and the projection 33a on the one side in the backup axis direction of the processing roller 32 of the second mold device 312 is the same as the distance between adjacent projections 33a in the width direction of each processing roller 32.

[0064] As shown in Figure 7, the first position and the second position are 90° apart in the circumferential direction of the backup roller 40. Specifically, the first position is the position vertically above the backup roller 40, and the second position is the position upstream in the direction of travel of the electrode plate 100 in the horizontal direction. The first to sixth mold devices 311 to 316 are arranged such that each processing roller 32 contacts the portion of the electrode plate 100 that is resting on the backup roller 40.

[0065] The first to sixth mold devices 311 to 316 are arranged such that the central axis C2 of the backup roller 40 lies on the extension line L of the axis of the cylinder rod 38a of each mold pressurizing cylinder 38. As a result, the central axes C1 of the processing rollers 32 of the first mold device 311, the third mold device 313, and the fifth mold device 315 and the central axis C2 of the backup roller 40 are located in the same vertical plane. Furthermore, the central axes C1 of the processing rollers 32 of the second mold device 312, the fourth mold device 314, and the sixth mold device 316 and the central axis C2 of the backup roller 40 are located in the same horizontal plane.

[0066] The arrangement of the first to sixth mold devices 311 to 316 allows the pressing force generated by each mold pressurizing cylinder 38 to be transmitted from the processing rollers 32 to the electrode plates 100 with almost no reduction. Each processing roller 32 can be pressed against the electrode plates 100 wrapped around the backup rollers 40 with a more appropriate pressing force.

[0067] (4) Inspection device The inspection device 65 shown in Figures 2 and 9 evaluates the depth of the holes 103 formed in the electrode plate 100 by the mold device 31. Specifically, the inspection device 65 determines whether the depth of the holes 103 formed by each processing roller is normal for each processing roller. If an abnormal hole 103 is found, it is determined that there is an abnormality in the processing roller 32 that formed the hole 103. The inspection device of this embodiment includes an irradiation device 70, a light receiving device 80, and a control unit 90.

[0068] (4-1) Irradiation device As shown in Figures 8 to 10, the irradiation device 70 has a light source 73 that emits inspection light. The light source 73 irradiates the processed surface in which the hole portion 103 is formed with inspection light. The inspection light is laser light. The inspection light may be an LED or collimated light. The light source 73 is fixed at a position spaced away from the processed surface and irradiates the processed surface of the electrode plate 100 as it is transported in the direction of travel for a predetermined period of time.

[0069] Here, the portion of the processed surface that is irradiated with inspection light is defined as the irradiation area P. Multiple holes 103 flowing in the direction of travel pass through the irradiation area P in sequence. In other words, the light source 73 irradiates multiple holes 103 flowing in the direction of travel in sequence, as shown by the dashed arrows in Figure 8.

[0070] The irradiation device 70 has a plurality of light sources 73. Specifically, the irradiation device has six light source units LU. Each light source unit LU has a first light source 73a, a second light source 73b, and a third light source 73c. ​​In other words, the irradiation device of this embodiment has 18 light sources 73.

[0071] One light source unit LU irradiates inspection light onto multiple holes 103 formed by one processing roller 32. Specifically, the first light source unit LU1 irradiates inspection light onto the holes 103 formed by the first processing roller 32 of the first mold device 311. The second light source unit LU2 irradiates inspection light onto the holes 103 formed by the second processing roller 32 of the second mold device 312. The third light source unit LU3 irradiates inspection light onto the holes 103 formed by the third processing roller 32 of the third mold device 313. The fourth light source unit LU4 irradiates inspection light onto the holes 103 formed by the fourth processing roller 32 of the fourth mold device 314. The fifth light source unit LU5 irradiates inspection light onto the holes 103 formed by the fifth processing roller 32 of the fifth mold device 315. The sixth light source unit LU6 irradiates inspection light onto the holes 103 formed by the sixth processing roller 32 of the sixth mold apparatus 316. In this way, each light source unit LU irradiates multiple holes 103 formed by the corresponding processing roller 32.

[0072] As shown in Figure 8, the first light source 73a, the second light source 73b, and the third light source 73c of each light source unit LU are arranged in a single row in order in the width direction of the electrode plate 100 when the processed surface is viewed from above. The configuration of the first light source 73a, the second light source 73b, and the third light source 73c is the same; only their arrangement differs. Hereinafter, the first light source 73a, the second light source 73b, and the third light source 73c may be collectively referred to simply as light source 73. The multiple dots shown in Figure 8 indicate multiple holes 103. The dashed arrows indicate the direction of propagation of light emitted from each light source.

[0073] Each light source 73 is positioned such that, when the workpiece surface is viewed from above, the inspection light traveling in a straight line from the light source 73 is directed upstream (rearward) in the direction of travel of the electrode plate 100. Each light source 73 illuminates a different position on the workpiece surface. When the positions on the workpiece surface illuminated by the first light source 73a, the second light source 73b, and the third light source 73c (irradiation areas P) are designated as the first irradiation area P1, the second irradiation area P2, and the third irradiation area P3, respectively, when the workpiece surface is viewed from above, the first irradiation area P1, the second irradiation area P2, and the third irradiation area P3 are arranged in a line in order in the width direction of the electrode plate 100.

[0074] Each irradiation area P1 to P3 has a predetermined size (the elliptical area enclosed by the dashed line in Figure 8). For example, if the projection diameter of the light source is 5 mm and the hole 103 on the processing surface is 1 mm ２ If approximately 200 holes are formed per area, the total number of holes 103 within the irradiation area P will be approximately 4000. In this example, each light source 73 continuously irradiates approximately 4000 holes 103. Note that in Figure 8, the shape of each irradiation area P1 to P3 is elliptical when viewed from above on the processed surface, but it may also be rectangular or any other polygon.

[0075] As shown in Figure 9, each light source 73 is positioned such that the angle of incidence when the inspection light enters the electrode plate 100 is α. The angle of incidence α is the angle between the line connecting the irradiation area P on the work surface that is struck by the inspection light emitted from the light source 73 and the position of the light source 73, and the perpendicular line to the work surface in the irradiation area P.

[0076] As shown in Figure 2, in this embodiment, each irradiation area P is located on the processing surface where the electrode plate 100 and the outer circumferential surface of the third guide roller 15 are in contact. That is, each light source 73 irradiates inspection light to the position where the electrode plate 100 and the outer circumferential surface of the third guide roller 15 are in contact. In other words, each light source 73 irradiates the processing surface of the electrode plate 100 wrapped around the third guide roller 15. In this case, the perpendicular to the processing surface is the perpendicular to the tangent in the irradiation area P.

[0077] During the predetermined period while the unwinding roller 10 is rotating, the electrode plate 100 is moving in the direction of travel. Therefore, the light source 73 continues to irradiate the moving electrode plate 100, which is in contact with the outer surface of the third guide roller 15, with inspection light.

[0078] (4-2) Light Receiving Device As shown in Figures 8 to 10, the light receiving device 80 has a detection unit 83 that detects inspection light. The detection unit 83 is a sensor that detects inspection light. The detection unit 83 has a light-receiving element such as a photodiode. The detection unit 83 detects the inspection light reflected by the electrode plate 100. In other words, the detection unit 83 detects the reflected light reflected from the irradiated area P of the processed surface.

[0079] The light receiving device 80 has a plurality of detection units 83. Specifically, the light receiving device has six detection units DU. Each detection unit has a first detection unit 83a, a second detection unit 83b, and a third detection unit 83c. In other words, the light receiving device 80 of this embodiment has 18 detection units.

[0080] Each detection unit DU detects the reflected light of the inspection light emitted from the corresponding light source unit LU. Specifically, the first detection unit DU1 corresponds to the first light source unit LU1. The second detection unit DU2 corresponds to the second light source unit LU2. The third detection unit DU3 corresponds to the third light source unit LU3. The fourth detection unit DU4 corresponds to the fourth light source unit LU4. The fifth detection unit DU5 corresponds to the fifth light source unit LU5. The sixth detection unit DU6 corresponds to the sixth light source unit LU6.

[0081] Each detection unit 83 detects the reflected light of the inspection light emitted from the corresponding light source 73. Specifically, the first detection unit 83a detects the reflected light of the inspection light emitted from the first light source 73a. The second detection unit 83b detects the reflected light of the inspection light emitted from the second light source 73b. The third detection unit 83c detects the reflected light of the inspection light emitted from the third light source 73c. ​​In this way, each detection unit 83 of the detection unit DU detects the reflected light of the inspection light emitted from the light source of the light source unit LU corresponding to the detection unit DU. The first detection unit 83a, the second detection unit 83b, and the third detection unit 83c have the same configuration, differing only in their arrangement. Hereinafter, the first detection unit 83a, the second detection unit 83b, and the third detection unit 83c may be collectively referred to simply as the detection unit 83.

[0082] As shown in Figure 8, the detection unit 83 is arranged to face the direction of travel of the light source 73 and the electrode plate 100. Specifically, the first detection unit 83a is positioned upstream (rear) of the electrode plate 100 in the direction of travel of the electrode plate 100 compared to the first light source 73a. The second detection unit 83b is positioned upstream (rear) of the electrode plate 100 in the direction of travel of the electrode plate 100 compared to the second light source 73b. The third detection unit 83c is positioned upstream (rear) of the electrode plate 100 in the direction of travel of the electrode plate 100 compared to the third light source 73c.

[0083] As shown in Figure 9, the detection unit 83 is positioned such that the reflection angle of the inspection light reflected from the irradiation area P on the workpiece surface is β. The reflection angle β is the angle between the line connecting the irradiation area P and the position of the detection unit 83 and the perpendicular line to the workpiece surface in the irradiation area P. The reflection angle β is equal to the incident angle α.

[0084] Thus, the detection unit 83 continuously detects the inspection light reflected from the processed surface while the light source 73 is irradiating the surface with inspection light. Specifically, the detection unit 83 detects the inspection light reflected from each irradiation area P on the processed surface. Therefore, the inspection device 65 of this embodiment performs inspection on a plurality of holes 103 that enter each irradiation area P. In other words, the inspection device 65 of this embodiment inspects some of the holes 103 on the processed surface and does not inspect all of them. Furthermore, the inspection device 65 of this embodiment does not evaluate the depth of each individual hole 103 within the irradiation area P, but evaluates the total depth of the plurality of holes 103 within the irradiation area P. That is, the inspection device 65 of this embodiment evaluates the trend of the total depth of the plurality of holes 103 that enter each irradiation area P.

[0085] (4-3) Operation Unit and Notification Unit The inspection device 65 has an operation unit 96 and a notification unit 97 (see Figure 10). The operation unit 96 receives commands from the user to cause the inspection device 65 to perform predetermined operations. The operation unit 96 has, for example, a touch panel or pressable buttons.

[0086] The notification unit 97 notifies the user of the inspection results from the inspection device 65. The notification unit 97 is, for example, a display or a speaker. The notification unit 97 displays the inspection results on a display or notifies the user by sound from a speaker.

[0087] (4-4) Control Unit As shown in Figure 10, the control unit 90 is connected to various devices of the inspection apparatus 65 in a communicative manner. Communication includes sending and receiving predetermined information as signals between the control unit 90 and the devices. The control unit 90 includes an MCU (Micro Control Unit), electrical circuits, and electronic circuits. The MCU includes a CPU (Central Processing Unit), memory, and a communication interface. Various programs for the CPU to execute are stored in the memory.

[0088] The control unit 90 controls the on / off switching of the irradiation device 70 and the light receiving device 80, and the like. The control unit 90 evaluates the depth of the hole 103 formed in the processed surface based on the intensity of the inspection light detected by the light receiving device 80. The control unit 90 of the present embodiment performs a first determination operation and a second determination operation.

[0089] The first determination operation is an operation of determining whether the depth of the hole 103 formed in the processed surface is normal. The second determination operation is an operation of determining whether the parallelism between each processed surface of the electrode plate 100 and the processed surface 33b of the processing roller 32 is normal when the electrode plate 100 is in contact with the outer circumferential surface of each processing roller 32.

[0090] (4-3-1) First Determination Operation The control unit 90 obtains a first index indicating the intensity of the inspection light detected by the detection unit 83, and evaluates the depth of the hole 103 based on the relationship between the depth of the hole 103 and the first index.

[0091] Specifically, the control unit 90 receives a signal indicating the intensity of reflected light from the detection unit 83 that has detected the reflected light from the processed surface, and converts the signal into a voltage serving as the first index. The voltage indicates the reflection intensity, and the higher the reflection intensity, the higher the voltage.

[0092] As shown in FIG. 11, the control unit has data indicating the relationship between the depth of the hole 103 and the voltage. Here, when the hole 103 passes through the irradiation region P, the intensity of the inspection light reflected by the hole 103 changes depending on the depth of the hole 103. The deeper the depth of the hole 103, the smaller the reflection intensity. Therefore, the relationship between the depth of the hole 103 and the voltage shown in FIG. 11 can be approximated to a predetermined linear equation in which the deeper the depth of the hole 103, the smaller the voltage.

[0093] Let the depth D of the normal hole 103 be the reference value D ０ , and let the reference value D ０ Let the voltage V corresponding to be V ０ . The control unit 90 determines that the depth D of the hole 103 is normal when the voltage V is within the first range. The first range is, for example, the range of the voltage V corresponding to within ±10% of the reference value D ０ Specifically, let the value of -10% of the reference value D ０ be Dmin, and the reference value D ０When Dmax is +10% of the value, the normal depth D of the hole 103 is when Dmin ≤ D ≤ Dmax. When Vmax is the voltage V corresponding to Dmin and Vmin is the voltage V corresponding to Dmax, the control unit 90 determines that the depth D of the hole 103 is normal when the voltage V is in the range of Vmin ≤ V ≤ Vmax.

[0094] The control unit 90 performs a first determination operation based on the reflection intensity detected by the first detection unit 83a, the second detection unit 83b, and the third detection unit 83c, respectively. Specifically, the control unit 90 determines the degree of normality of the depth of each of the multiple holes 103 formed on the processed surface that enter each irradiation area.

[0095] Specifically, the depth D of the hole 103 that passes through the first irradiation region P1 is D １ The depth D of the hole 103 that passes through the second irradiation region P2 is D ２ The depth D of the hole 103 that passes through the third irradiation region P3 is D ３ Let's assume that. D １ , D ２ , D ３ The voltages V corresponding to each of these are V １ , V ２ , V ３ In this case, the control unit 90 determines Vmin ≤ V １ ≤ Vmax, Vmin ≤ V ２ ≤ Vmax and Vmin ≤ V ３ When all conditions ≤ Vmax are met, the depth of the hole 103 formed on the machined surface is determined to be normal. The control unit 90 determines for each of the six detection units DU V １ , V ２ , V ３ By determining this, it is possible to determine whether the holes 103 formed on the processed surface of each of the six processing rollers 32 are normal.

[0096] (4-3-2) Second decision operating voltage V １ , V ２ , V ３ Even when V is within the first range, １ <V ２ <V ３ When the conditions are met, or V １ >V２ >V ３ When this condition is met, it can be seen that the depths of the holes 103, which are aligned in the width direction of the machined surface, become progressively shallower or deeper in the width direction of the machined surface. In such a case, for example, it can be determined that the axis of the corresponding machined roller 32 is offset from the axis of the backup roller 40.

[0097] The control unit is V １ <V ２ <V ３ , or V １ >V ２ >V ３ Satisfying the conditions, and V １ and V ２ The absolute value of the difference between X and V ２ and V ３ If the absolute value Y of the difference between the two is greater than or equal to a predetermined value δ, it is determined that the parallelism between the machined surface and the machined surface of the machining roller 32 is abnormal. The predetermined value δ is any value.

[0098] (5) Inspection Method The inspection method for the hole 103 will be described. The inspection method for the hole 103 includes the steps of determining the voltage that indicates the intensity of the reflected light of the inspection light irradiated toward the processed surface in which the hole 103 is formed, and evaluating the depth of the hole 103 based on the relationship between the depth of the hole 103 and the voltage. The inspection method includes a first determination operation and a second determination operation. The inspection method performed by the control unit 90 will be described using Figure 12.

[0099] In step ST01, the control unit 90 determines the V from the detected reflected light for each detection unit DU. １ , V ２ , V ３ Calculate.

[0100] In step ST02, the control unit 90 controls each detection unit DU V １ , V ２ , V ３ Determine whether all of Vmin ≤ V ≤ Vmax. １ , V ２ , V ３ If all of Vmin ≤ V ≤ Vmax (YES in step ST02), then step ST05 is executed. １ , V ２ , V３ If at least one of the values ​​does not satisfy Vmin ≤ V ≤ Vmax (NO in step ST02), then step ST03 is executed.

[0101] In step ST03, the control unit 90, in step ST02, V １ , V ２ , V ３ Identify the processing roller 32 corresponding to the detection unit DU in which at least one of the values ​​does not satisfy Vmin ≤ V ≤ Vmax.

[0102] In step ST04, the control unit 90 notifies the user that an abnormality has been found in the depth of the hole 103 and identifies the processing roller 32 that was identified in step ST03. The user can then stop the operation of the processing device 1 and repair or replace the corresponding processing roller 32.

[0103] In step ST05, the control unit 90 is V １ <V ２ <V ３ or V １ >V ２ >V ３ The system determines whether there is a detection unit DU that satisfies the first condition. If there is no detection unit DU that satisfies the first condition (YES in step ST05), it is determined that the depth of the hole 103 is normal and the parallelism between the machined surface and the workpiece surface is normal, and step ST01 is executed again for the next hole 103 in the direction of travel. If there is a detection unit DU that satisfies the first condition (NO in step ST05), step ST06 is executed.

[0104] In step ST06, the control unit 90 identifies a detection unit DU that satisfies the first condition, and for the detection unit DU, V １ and V ２ The absolute value of the difference between, α, or V. ２ and V ３It is determined whether the second condition is met, which is that the absolute value β of the difference between the two values ​​is greater than or equal to a predetermined value γ. If the second condition is met (YES in step ST06), step ST07 is executed. If the second condition is not met (NO in step ST06), it is determined that the depth of the hole 103 is normal and the parallelism between the machined surface and the workpiece surface is also normal, and step ST01 is executed again for the next hole 103 in the direction of travel.

[0105] In step ST07, the control unit 90 determines that the parallelism between the workpiece surface and the processing surface is abnormal for the processing roller 32 corresponding to the detection unit DU that was determined to satisfy the second condition in step ST06, and notifies the user of this fact, as well as the processing roller 32. The user can stop the operation of the processing device 1 and repair or replace the processing roller 32 in question.

[0106] (6) Features (6-1) Feature 1 The inspection device 65 of this embodiment includes a light source 73 that irradiates inspection light toward a processed surface in which a hole 103 is formed, a detection unit 83 that detects the inspection light reflected from the processed surface, and a control unit 90 that determines a first index indicating the intensity of the inspection light detected by the detection unit 83 and evaluates the depth of the hole 103 based on the relationship between the depth of the hole 103 and the first index.

[0107] According to this method, the depth of the holes can be easily evaluated based on the reflection intensity of inspection light irradiated onto the processed surface of the electrode plate 100. Therefore, it is possible to avoid the trouble of taking photographs of the holes 103 and analyzing the image data. In particular, as in this embodiment, the burden of inspection can be reduced when there are a relatively large number of holes 103.

[0108] (6-2) Feature 2 In the inspection device 65 of this embodiment, the electrode plate 100 is fed in the direction of travel and comes into contact with a projection 33a formed on the outer surface of the processing roller 32 which rotates in the direction of travel, thereby forming a plurality of holes 103 on the processed surface. The light source 73 irradiates the electrode plate 100 in motion with inspection light for a predetermined period of time, and the detection unit 83 detects the inspection light continuously reflected from the processed surface.

[0109] According to this, the depth of multiple holes 103 aligned in the direction of travel can be continuously evaluated, thus reducing the workload of inspection. Furthermore, since the depth of the continuously formed holes 103 can be monitored during the manufacturing of the electrode plate 100, abnormalities in the holes 103 can be quickly detected, for example. In addition, if an abnormality in a hole 103 is found, wear of the projection 33a on the outer surface of the processing roller 32 that formed the hole 103 can be determined. Specifically, since the projection 33a continuously forms the holes 103, as the projection 33a shortens due to wear, the depth of the multiple continuously formed holes 103 gradually becomes shallower from the beginning to the end. Therefore, by inspecting the depth of multiple holes passing through the irradiation region P in order for each region P, if there is an irradiation region P corresponding to multiple holes formed in such a way that the depth of the holes becomes progressively shallower, it can be determined that the projection 33a of the processing roller 32 corresponding to that irradiation region P is showing a greater degree of wear.

[0110] (6-3) Feature 3 In the inspection apparatus 65 of this embodiment, the light source 73 has six light source units LU. Each light source unit LU irradiates a plurality of holes 103 formed by the corresponding processing roller 32. Each light source unit LU has a first light source 73a, a second light source 73b, and a third light source 73c. ​​The detection unit 83 has a first detection unit 83a corresponding to the first light source 73a, a second detection unit 83b corresponding to the second light source 73b, and a third detection unit 83c corresponding to the third light source 73c. ​​The first light source 73a, the second light source 73b, and the third light source 73c are each arranged to irradiate different positions (irradiation areas P) on the feed-out electrode plate 100.

[0111] According to this, it is possible to evaluate whether the holes 103 passing through each position (irradiation area P) irradiated by the first light source 73a, the second light source 73b, and the third light source 73c are formed normally. If there is only one light source 73, only the holes 103 in one area P as viewed from the direction of travel can be evaluated, but since the depth of the holes 103 in three areas can be evaluated, the accuracy of determining abnormalities in the holes 103 is improved. Furthermore, if the first light source 73a, the second light source 73b, and the third light source 73c are arranged to irradiate different positions in the width direction of the electrode plate, and the measured depths of the holes are different in each case, it is possible to detect that the electrode plate is not in uniform contact with the surface of the processing roller. This makes it possible to understand, for example, that the axis of the processing roller is misaligned with respect to the processing surface of the electrode plate, or that the pressing force of the projection of the processing roller against the electrode plate is not appropriate.

[0112] In addition, in this embodiment, six light source units LU are used to correspond to the inspection of the holes 103 formed by each of the six processing rollers 32. Each of the six light source units LU is provided with a first light source 73a, a second light source 73b, and a third light source 73c, and the detection unit 83 detects the inspection light from the first light source 73a, the second light source 73b, and the third light source 73c of each light source unit LU. This makes it possible to determine whether the depth of the hole 103 formed on each processing roller 32 is normal or not. Furthermore, if a hole 103 with an abnormal depth is found, it can be determined that there is a problem with the processing roller 32 that formed the hole 103. For example, if an abnormality is found in the depth of the hole 103, it can be determined that the projection 33a of the processing roller 32 that formed the hole 103 is worn, the axis of the processing roller 32 that formed the hole 103 is misaligned with respect to the processing surface, or the pressing force applied by the processing roller 32 to the processing surface is not appropriate.

[0113] (6-4) Feature 4 In the inspection apparatus 65 of this embodiment, the electrode plate 100 is guided in the direction of travel by a third guide roller 15 positioned downstream of the processing roller 32, and the light source 73 irradiates inspection light onto the irradiation area P, which is the part of the processing surface where the electrode plate 100 and the outer circumferential surface of the third guide roller 15 are in contact.

[0114] According to this, when the electrode plate 100 is in contact with the third guide roller 15, the electrode plate 100 is supported by the third guide roller 15, resulting in relatively small vibrations (wobble). By irradiating this area with inspection light, the reflectance intensity can be stably detected.

[0115] (6-5) Feature 5 The first indicator in this embodiment is voltage. In this way, the depth of the hole 103 can be determined by the voltage value.

[0116] (6-6) Feature 6 In the inspection device 65 of this embodiment, the control unit 90 determines that the depth of the hole 103 is normal when the voltage is within a first range, and the first range is a voltage range that corresponds to within ±10% of the reference value of the depth of the hole 103.

[0117] According to this, the voltage value can be used to determine if the depth of the hole 103 is abnormal. By simply checking the voltage value, the user can easily determine which processing roller 32 has a problem with its projection 33a.

[0118] (7) Other embodiments The inspection apparatus of the above embodiment may be configured as follows.

[0119] There is no limit to the number of light source units LU and detection units DU provided in the inspection device 65; they may be provided according to the number of processing rollers 32, or they may be provided regardless of the number of processing rollers 32.

[0120] The light source unit LU of the inspection device 65 is not limited to three light sources; it may have one, two, or four or more. The more light sources 73 there are, the more accurately the abnormality of the depth of the hole 103 can be determined, and the degree of tilt of the axis of each processing roller 32 can be detected more precisely.

[0121] The multiple light sources 73 of the inspection device 65 do not have to be unitized as in the above embodiment. Similarly, the detection unit 83 does not have to be unitized.

[0122] If there is an area on the electrode plate 100 where the active material layer is not coated, the control unit 90 may control the irradiation device 70 so as not to irradiate that area with inspection light while it passes through the irradiation area P. For example, if the active material layer is coated on the electrode plate 100 at regular intervals in the direction of travel (longitudinal direction), the irradiation device 70 intermittently irradiates the area with inspection light so as not to irradiate the uncoated portion.

[0123] The first range is not limited to a range of ±10% of the reference value of the depth of the hole 103, but may be a range of ±5% to 10%.

[0124] The roller corresponding to the first roller in this disclosure may be located downstream in the direction of travel from the processing roller 32 or the backup roller 40, and is not limited to the third guide roller 15. The first roller may be the second support roller 14a constituting the second dancer section 14, or the fourth guide roller 16.

[0125] The multiple light sources 73 do not necessarily have to be arranged so that the multiple irradiation areas P are perpendicular to the width direction of the processed surface.

[0126] The first indicator does not have to be voltage; for example, it may be the reflectance itself. The reflectance is detected or measured by a known method.

[0127] Multiple detection units (83) may be provided for a single light source (73) (for example, a line laser). In other words, multiple detection units (83) may detect the reflected light of the inspection light emitted from a single light source (73). This eliminates the need to install a pair of light source (73) and detection unit (83), and reduces the number of light sources (73) to be installed. As a result, the configuration of the inspection device (65) can be simplified, and the number of parts used in the inspection device (65) can be reduced, thereby achieving lower costs.

[0128] When a pair of detection units (83) and light sources (73) arranged downstream of the light source (73) in the direction of travel of the electrode plate (100) is defined as the first pair, and a pair of detection units (83) and light sources (73) arranged upstream of the light source (73) in the direction of travel of the electrode plate (100) is defined as the second pair, the light sources (73) and detection units (83) in the inspection device (65) may be the first pair, the second pair, or a combination thereof. When the first pair and the second pair are combined, the first pair and the second pair may be arranged alternately in the width direction of the electrode plate (100), or the first pair and the second pair may be arranged alternately for each light source unit (LU) and detection unit (DU).

[0129] While embodiments and variations have been described above, it will be understood that a variety of modifications to the form and details are possible without departing from the spirit and scope of the claims. Furthermore, these embodiments and variations may be combined or substituted as appropriate, as long as they do not impair the functions covered by this disclosure.

[0130] The technology disclosed herein is useful as an inspection apparatus and inspection method for evaluating the depth of holes formed in an electrode plate.

[0131] 32 Processing roller 33a Protrusion 65 Inspection device 73 Light source 73a First light source 73b Second light source 83 Detection unit 83a First detection unit 83b Second detection unit 90 Control unit 100 Electrode plate 103 Hole P Irradiation area

Claims

1. An inspection device for inspecting the depth of a plurality of bottomed holes formed on a machined surface of an electrode plate, comprising: a light source that irradiates inspection light toward the machined surface on which the holes are formed; a detection unit that detects the inspection light reflected from the machined surface; and a control unit that determines a first index indicating the intensity of the inspection light detected by the detection unit, and evaluates the depth of the holes based on the relationship between the depth of the holes and the first index.

2. The inspection apparatus according to claim 1, wherein the electrode plate is fed in the direction of travel and comes into contact with a projection formed on the outer circumferential surface of a processing roller that rotates in the direction of travel, thereby forming a plurality of holes on the processed surface, the light source irradiates the electrode plate in motion with the inspection light for a predetermined period of time, and the detection unit detects the inspection light continuously reflected from the processed surface.

3. The inspection apparatus according to claim 2, wherein the light source comprises a first light source and a second light source, the detection unit comprises a first detection unit and a second detection unit, the first detection unit detects inspection light emitted from the first light source, the second detection unit detects inspection light emitted from the second light source, and the first light source and the second light source are arranged to illuminate different positions on the electrode plate being fed out.

4. The inspection apparatus according to claim 2 or 3, wherein the electrode plate is guided in the direction of travel by a first roller positioned downstream of the processing roller, and the light source irradiates the inspection light into the irradiation area where the electrode plate and the outer surface of the first roller are in contact.

5. The inspection apparatus according to any one of claims 1 to 3, wherein the first indicator is voltage or reflectance.

6. The inspection apparatus according to any one of claims 1 to 3, wherein the control unit determines that the depth of the hole is normal when the first indicator is within a first range, and the first range is a range of the first indicator that corresponds to within ±5 to 10% of the reference value of the depth of the hole.

7. An inspection method for inspecting the depth of a plurality of bottomed holes formed on a machined surface of an electrode plate, comprising the steps of: determining a first index indicating the intensity of reflected light from an inspection light irradiated toward the machined surface on which the holes are formed; and evaluating the depth of the holes based on the relationship between the depth of the holes and the first index.

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