Detection device, prediction apparatus, detection method, and prediction method

Abstract

Provided is a detection device for detecting metal foreign matter falling through the atmosphere. A detection device (1) comprises an electrode sheet (5), a measurement unit (31), and a determination unit (32). The electrode sheet (5) has a pair of counter electrodes (11, 12) and an insulating sheet (13). The pair of counter electrodes (11, 12) include a first counter electrode (11) and a second counter electrode (12). The insulating sheet (13) supports the pair of counter electrodes (11, 12). The first counter electrode (11) has a plurality of first wiring electrode parts (11a), and the second counter electrode (12) has a plurality of second wiring electrode parts (12a). The plurality of second wiring electrode parts (12a) are arranged alternately with the plurality of first wiring electrode parts (11a) with spaces (s1) therebetween. The measurement unit (31) measures electrical numerical values between the pair of counter electrodes (11, 12). The determination unit (32) determines, on the basis of the measurement result of the measurement unit (31), whether or not a short circuit has occurred between the pair of counter electrodes (11, 12) due to metal foreign matter (F1) falling through the atmosphere.

Description

Detection device, prediction device, detection method, and prediction method

[0001] The present disclosure generally relates to a detection device, a prediction device, a detection method, and a prediction method, and more particularly to a detection device including an electrode sheet, a prediction device including the detection device, a detection method using the electrode sheet, and a prediction method including the detection method.

[0002] The metal particle detection sensor described in Patent Document 1 is disposed in lubricating oil to detect the presence or absence of metal fine particles floating in the lubricating oil. This metal particle detection sensor includes an insulating substrate, a pair of comb-shaped electrodes formed on the insulating substrate, a power source that applies a high voltage (30 V to 50 V) between the pair of comb-shaped electrodes, and a detection unit that detects a pulse voltage generated between the pair of comb-shaped electrodes.

[0003] In this metal particle detection sensor, a high voltage is applied between a pair of comb-shaped electrodes. When a bridge in which metal fine particles are connected in series is formed between the pair of comb-shaped electrodes due to the application of this voltage, a pulse voltage is generated between the pair of comb-shaped electrodes. Since this pulse voltage is proportional to the square of the particle diameter of the metal fine particles connected in series, it is possible to estimate the size of the metal fine particles from the magnitude of the pulse voltage.

[0004] In the metal particle detection sensor described in Patent Document 1, the phenomenon that a bridge formed by connecting metal fine particles in series is formed between a pair of comb-shaped electrodes by applying a high voltage between the pair of comb-shaped electrodes is utilized. However, this phenomenon can easily occur in lubricating oil, but it cannot easily occur in the atmosphere. Therefore, it is difficult to use the metal particle detection sensor described in Patent Document 1 for detecting metal foreign matter falling in the atmosphere.

[0005] Japanese Patent Application Laid-Open No. 4-297864

[0006] An object of the present disclosure is to provide a detection device, a prediction device, a detection method, and a prediction method capable of detecting metal foreign matter falling in the atmosphere.

[0007] A detection device according to one aspect of the present disclosure comprises an electrode sheet, a measuring unit, and a determination unit. The electrode sheet has a pair of counter electrodes and an insulating sheet. The pair of counter electrodes includes a first counter electrode and a second counter electrode. The insulating sheet supports the pair of counter electrodes. The first counter electrode has a plurality of first wiring electrode portions, and the second counter electrode has a plurality of second wiring electrode portions. The plurality of second wiring electrode portions are arranged alternately with the plurality of first wiring electrode portions at intervals. The measuring unit measures an electrical value between the pair of counter electrodes. The determination unit determines, based on the measurement result of the measuring unit, whether or not a short circuit has occurred between the pair of counter electrodes due to a metallic foreign object falling in the atmosphere.

[0008] A prediction device according to one aspect of the present disclosure comprises the detection device. The electrode sheet of the detection device has a plurality of pairs of counter electrodes, including the pair of counter electrodes. The spacing between each of the plurality of pairs of counter electrodes is of a different size. The insulating sheet of the electrode sheet supports the plurality of pairs of counter electrodes. The prediction device comprises a time measuring unit and a prediction unit. The time measuring unit measures the detection time of the short circuit caused by the metal foreign object smaller than a predetermined size, which has been determined to have occurred by the determination unit. The prediction unit predicts the detection time of the short circuit caused by the metal foreign object of a predetermined size falling through the atmosphere. The detection time is the time from a predetermined point in time to the point in time when the determination unit determines that the short circuit has occurred. The prediction unit determines the correlation between the spacing between two or more predetermined pairs of counter electrodes, where the spacing is smaller than the predetermined size, and the detection time, and predicts the detection time of the short circuit caused by the metal foreign object of a predetermined size based on the determined correlation.

[0009] A detection method according to one aspect of the present disclosure comprises a measurement step and a determination step. In the measurement step, an electrical value is measured between a pair of counter electrodes of an electrode sheet. The electrode sheet comprises the pair of counter electrodes and an insulating sheet. The pair of counter electrodes includes a first counter electrode and a second counter electrode. The insulating sheet supports the pair of counter electrodes. The first counter electrode has a plurality of first wiring electrode portions, and the second counter electrode has a plurality of second wiring electrode portions. The plurality of second wiring electrode portions are arranged alternately with the plurality of first wiring electrode portions at intervals. In the determination step, based on the measurement result of the measurement step, it is determined whether or not a short circuit has occurred between the pair of counter electrodes due to a metallic foreign object falling in the atmosphere.

[0010] A prediction method according to one aspect of the present disclosure includes the detection method. The electrode sheet of the detection method has a plurality of pairs of counter electrodes, including the pair of counter electrodes. The spacing between each of the plurality of pairs of counter electrodes is of a different size. The insulating sheet of the electrode sheet supports the plurality of pairs of counter electrodes. The prediction method further comprises a time measurement step and a prediction step. In the time measurement step, the detection time of the short circuit caused by the metal foreign object smaller than a predetermined size, which is determined to have occurred by the determination step, is measured. In the prediction step, the detection time of the short circuit caused by the metal foreign object of a predetermined size falling through the air is predicted. The detection time is the time from a predetermined point in time to the point in time when the determination step determines that the short circuit has occurred. In the prediction step, a correlation is found between the spacing between two or more predetermined pairs of counter electrodes, where the spacing is smaller than the predetermined size, and the detection time, and based on the found correlation, the detection time of the short circuit caused by the metal foreign object of a predetermined size is predicted.

[0011] Figure 1 is a configuration diagram of the detection device according to Embodiment 1. Figure 2 is a cross-sectional view taken along line A1-A1 in Figure 1. Figure 3 is an explanatory diagram illustrating the relationship between the size of the metal foreign object and the spacing of the wiring electrode section. Figure 4 is another explanatory diagram illustrating the relationship between the size of the metal foreign object and the spacing of the wiring electrode section. Figure 5 is yet another explanatory diagram illustrating the relationship between the size of the metal foreign object and the spacing of the wiring electrode section. Figure 6 is an explanatory diagram illustrating an example of the relationship between the short-circuit rate and the size of the foreign object. Figure 7 is an explanatory diagram illustrating an example of the relationship between the number of foreign objects and the size of the foreign object. Figure 8 is an explanatory diagram illustrating an example of the relationship between the number of detected objects and the size of the foreign object. Figure 9 is a flowchart illustrating the operation of the above detection device. Figure 10 is a configuration diagram of the detection device according to Embodiment 2. Figure 11 is a flowchart illustrating the operation of the above detection device. Figure 12 is a configuration diagram of the detection device according to Embodiment 3. Figure 13 is a flowchart illustrating the operation of the above detection device. Figure 14 is a configuration diagram of the prediction device according to Embodiment 4. Figure 15 is an explanatory diagram illustrating an example of the correlation between the size of the foreign object and the detection time. Figure 16 is a flowchart illustrating the operation of the above prediction device. Figure 17 is an explanatory diagram illustrating the electrode sheet portion of the prediction device according to a modified example 1 of Embodiment 4. Figure 18 is a configuration diagram of the prediction device according to Embodiment 5. Figure 19 is a flowchart illustrating the operation of the same prediction device.

[0012] A detection device according to an embodiment will be described with reference to the drawings.

[0013] (1) Embodiment 1 The detection device 1 according to Embodiment 1 will be described with reference to Figures 1 to 9.

[0014] (1-1) Overview The detection device 1 according to Embodiment 1, as shown in Figure 1, comprises an electrode sheet 5, a measuring unit 31, and a determination unit 32. The electrode sheet 5 has a pair of opposing electrodes 11, 12 and an insulating sheet 13. The pair of opposing electrodes 11, 12 includes a first opposing electrode 11 and a second opposing electrode 12. The insulating sheet 13 supports the pair of opposing electrodes 11, 12. The first opposing electrode 11 has a plurality (three in the example of Figure 1) of first wiring electrode portions 11a, and the second opposing electrode 12 has a plurality (two in the example of Figure 1) of second wiring electrode portions 12a. The plurality of second wiring electrode portions 12a are arranged alternately with the plurality of first wiring electrode portions 11a at intervals s1. The measuring unit 31 measures the electrical value between the pair of opposing electrodes 11, 12. The determination unit 32 determines, based on the measurement results from the measurement unit 31, whether or not a short circuit has occurred between the pair of opposing electrodes 11 and 12 due to a metallic foreign object F1 falling through the air.

[0015] With this configuration, a metal foreign object F1 that falls into the atmosphere is positioned across the first wiring electrode section 11a and the second wiring electrode section 12a, making it possible to detect a metal foreign object F1 of a predetermined size (a size corresponding to the distance s1 between the first wiring electrode section 11a and the second wiring electrode section 12a).

[0016] (1-2) Detailed Description The detection device 1 according to Embodiment 1 detects metallic foreign matter F1 falling into the atmosphere. The detection device 1 can be used, for example, to detect metallic foreign matter F1 that is generated in the manufacturing process of lithium-ion batteries (for example, the electrode cutting process) and scattered into the surroundings.

[0017] As shown in Figure 1, the detection device 1 has an electrode sheet section 2 and a detection circuit section 3.

[0018] (1-2-1) Electrode Sheet Section The electrode sheet section 2 captures metallic foreign objects F1 falling in the atmosphere. As shown in Figure 1, the electrode sheet section 2 comprises an electrode sheet 5, a roller 6, and a drive mechanism 7.

[0019] The electrode sheet 5 is a sheet member that captures metallic foreign objects F1 falling through the air. The electrode sheet 5 may be flexible. The electrode sheet 5 comprises a pair of opposing electrodes 11 and 12 and an insulating sheet 13.

[0020] The pair of counter electrodes 11 and 12 are formed of, for example, copper and a copper alloy. The pair of counter electrodes 11 and 12 have a first counter electrode 11 and a second counter electrode 12 that face each other.

[0021] The first opposing electrode 11 is, for example, a comb-shaped electrode. The first opposing electrode 11 has a plurality (three in Figure 1) of first wiring electrode portions 11a and a first connecting portion 11b. Each of the plurality of first wiring electrode portions 11a is strip-shaped and arranged in a line with a certain distance between them in the width direction. That is, the plurality of first wiring electrode portions 11a are arranged parallel to each other. Each first wiring electrode portion 11a is assumed to be straight, but may also be curved. The first connecting portion 11b is, for example, strip-shaped and is connected to one end of the plurality of first wiring electrode portions 11a. The first connecting portion 11b is assumed to be straight, but may also be curved. The plurality of first wiring electrode portions 11a protrude from one of the two sides of the first connecting portion 11b in the width direction of the first connecting portion 11b.

[0022] The second opposing electrode 12 is, for example, a comb-shaped electrode. The second opposing electrode 12 has a plurality (two in Figure 1) second wiring electrode portions 12a and a second connecting portion 12b. Each of the plurality of second wiring electrode portions 12a is strip-shaped and arranged side by side with a certain distance between them in the width direction. That is, the plurality of second wiring electrode portions 12a are arranged parallel to each other. Each second wiring electrode portion 12a is assumed to be straight, but may also be curved. The second connecting portion 12b is, for example, strip-shaped and is connected to one end of the plurality of second wiring electrode portions 12a. The second connecting portion 12b is assumed to be straight, but may also be curved. The plurality of second wiring electrode portions 12a protrude from one of the two sides of the second connecting portion 12b in the width direction of the second connecting portion 12b.

[0023] Each of the multiple second wiring electrode sections 12a is positioned between the multiple first wiring electrode sections 11a. More specifically, the multiple second wiring electrode sections 12a are arranged so that the first wiring electrode sections 11a and the second wiring electrode sections 12a are arranged alternately. The first wiring electrode sections 11a and the second wiring electrode sections 12a are positioned with a certain distance s1 between them.

[0024] The widths w1 of the first wiring electrode portion 11a and the second wiring electrode portion 12a are the same size, but they may be different sizes.

[0025] A bias voltage is applied to one of the two opposing electrodes, the first opposing electrode 11 and the second opposing electrode 12, while the other opposing electrode is connected to ground.

[0026] In Figure 1, all of the multiple second wiring electrode sections 12a are arranged alternately with the multiple first wiring electrode sections 11a, but it is sufficient if at least a portion of the multiple second wiring electrode sections 12a are arranged alternately with the multiple first wiring electrode sections 11a. Similarly, all of the multiple first wiring electrode sections 11a are arranged alternately with the multiple second wiring electrode sections 12a, but it is sufficient if at least a portion of the multiple first wiring electrode sections 11a are arranged alternately with the multiple second wiring electrode sections 12a.

[0027] The insulating sheet 13 supports the first opposing electrode 11 and the second opposing electrode 12. The insulating sheet 13 is formed in sheet form from an insulating material (for example, a resin material (more specifically, PET resin and acrylic resin)). The insulating sheet 13 may be flexible.

[0028] The insulating sheet 13 has a first main surface 13a and a second main surface 13b (see Figure 2). The first main surface 13a is the top surface, and the second main surface 13b is the bottom surface. The first main surface 13a is provided with first recesses 131 (three in the example in Figure 2) and second recesses 132 (two in the example in Figure 2) (see Figure 2).

[0029] The first opposing electrode 11 is fitted and positioned in the first recess 131. The first recess 131 is formed to be the same shape and size as the first opposing electrode 11 when viewed from a plan view from a direction perpendicular to the first main surface 13a of the insulating sheet 13. When the first opposing electrode 11 is fitted and positioned in the first recess 131, the exposed surface (i.e., top surface) 11u of the first opposing electrode 11 is at the same height as, for example, the first main surface 13a of the insulating sheet 13. Therefore, the exposed surface (i.e., top surface) 11p of the first wiring electrode portion 11a is at the same height as, for example, the first main surface 13a of the insulating sheet 13. In the example of Figure 2, the exposed surfaces 11u and 11p are at the same height as the first main surface 13a of the insulating sheet 13, but the exposed surfaces 11u and 11p may be positioned on the bottom side of the first recess 131 than the first main surface 13a.

[0030] The second opposing electrode 12 is fitted and positioned in the second recess 132. The second recess 132 is formed to be the same shape and size as the second opposing electrode 12 when viewed from a plan view from a direction perpendicular to the first main surface 13a of the insulating sheet 13. When the second opposing electrode 12 is fitted and positioned in the second recess 132, the exposed surface (i.e., top surface) 12u of the second opposing electrode 12 is at the same height as, for example, the first main surface 13a of the insulating sheet 13. Therefore, the exposed surface (i.e., top surface) 12p of the second wiring electrode portion 12a is at the same height as, for example, the first main surface 13a of the insulating sheet 13. In the example of Figure 2, the exposed surfaces 12u and 12p are at the same height as the first main surface 13a of the insulating sheet 13, but the exposed surfaces 12u and 12p may be positioned on the bottom side of the second recess 132 than the first main surface 13a.

[0031] In the electrode sheet 5, if a metallic foreign object F1 is placed across the adjacent first wiring electrode portion 11a and second wiring electrode portion 12a, the first counter electrode 11 and the second counter electrode 12 will short-circuit. The metallic foreign object F1 is detected when this short-circuit is detected by the determination unit 32. The pair of counter electrodes 11 and 12 have a detection range 14 for detecting the metallic foreign object F1. The detection range 14 is the area surrounding the pair of counter electrodes 11 and 12.

[0032] As shown in Figure 1, the roller 6 moves while rolling over the detection range 14 of the electrode sheet 5. This movement causes the metal foreign object F1, which is positioned straddling the first wiring electrode portion 11a and the second wiring electrode portion 12a, to be pressed against the first wiring electrode portion 11a and the second wiring electrode portion 12a. Consequently, the short-circuit current flow state (i.e., the amount of current flow when a short circuit occurs) between the metal foreign object F1 and the first wiring electrode portion 11a and the second wiring electrode portion 12a is improved. As a result, the short circuit between the first wiring electrode 11a and the second wiring electrode portion 12a caused by the metal foreign object F1 becomes more reliable.

[0033] The roller 6 is driven by a drive mechanism 7. The roller 6 moves along a first direction T1 by the drive mechanism 7. The first direction T1 is the direction opposite to the first end 14a and the second end 14b of the detection range 14.

[0034] The roller 6 is cylindrical. The roller 6 is insulating. More specifically, the roller is made of an insulating material (for example, a resin material). The entire roller 6 may be made of an insulating material, or at least the surface of the roller 6 may be made of an insulating material. The insulating properties of the roller 6 prevent the first opposing electrode 11 and the second opposing electrode 12 from short-circuiting when the roller 6 moves on the electrode sheet 5.

[0035] In this electrode sheet 5, if a metal foreign object F1 of a predetermined size (a size corresponding to the spacing s1 (more specifically, a size the same as or larger than the spacing s1)) is placed across the first wiring electrode section 11a and the second wiring electrode section 12a, the metal foreign object F1 will cause a short circuit between the first opposing electrode 11 and the second opposing electrode 12. This short circuit is detected by the determination section 32 of the detection circuit section 3, which will be described later, and it is detected that a metal foreign object F1 of a predetermined size has fallen onto the electrode sheet 5.

[0036] Furthermore, in the electrode sheet 5, once a short circuit caused by the first (initial) metal foreign object F1 is detected, short circuits caused by subsequent metal foreign objects F1 cannot be distinguished from the short circuit caused by the first metal foreign object F1. For this reason, in the electrode sheet 5 of Embodiment 1, only the metal foreign object F1 of a predetermined size that first falls onto the electrode sheet 5 is detected.

[0037] The drive mechanism 7 moves the roller 6 in a first direction T1 across the detection range 14 of the electrode sheet 5 at regular intervals. As described above, the first direction T1 is the direction opposite to the first end 14a and the second end 14b. More specifically, when the drive mechanism 7 moves the roller 6 across the detection range 14, it may always move the roller 6 from the first end 14a to the second end 14b by returning the roller 6 to its original position at the first end 14a after the movement. Alternatively, when the drive mechanism 7 moves the roller 6 across the detection range 14, it may alternately change the direction of movement of the roller 6 between forward and reverse directions each time it moves, such as moving the roller 6 from the first end 14a to the second end 14b, and then moving the roller 6 from the second end 14b to the first end 14a.

[0038] The drive mechanism 7 includes a drive unit 71 and a guide unit 72.

[0039] The drive unit 71 is a drive source (e.g., a motor) for moving the roller 6 across the detection range 14. The roller 6 may be moved by rotation by the drive unit 71. Alternatively, the roller 6 may be rotated by friction between the roller 6 and the insulating sheet 13, as the central axis of the roller 6 is translated in the first direction T1 by the drive unit 71. The guide unit 72 guides the roller 6 so that it moves in the first direction T1. The guide unit 72 is positioned along the first direction T1 on at least one side of the first opposing electrode 11 and the second opposing electrode 12 (both sides in the example of Figure 1).

[0040] (1-2-2) Detection Circuit Section The detection circuit section 3 detects the metallic foreign object F1 captured by the electrode sheet section 2. More specifically, as shown in Figure 1, the detection circuit section 3 includes a measurement section 31, a determination section 32, a time measurement section 33, a display section 34, and a drive control section 35.

[0041] The measurement unit 31 measures the electrical value between the first counter electrode 11 and the second counter electrode 12. The measurement unit 31 measures, for example, a resistance value as the electrical value. Note that the measurement unit 31 may measure, for example, a current value as the electrical value.

[0042] The determination unit 32 determines whether or not a short circuit has occurred between the first counter electrode 11 and the second counter electrode 12 due to the metal foreign object F1 based on the measurement result of the measurement unit 31. More specifically, when the resistance value between the first counter electrode 11 and the second counter electrode 12 is less than a predetermined value, the determination unit 32 determines that a short circuit has occurred between the first counter electrode 11 and the second counter electrode 12 due to the metal foreign object F1. Further, when the resistance value between the first counter electrode 11 and the second counter electrode 12 is greater than or equal to the predetermined value, the determination unit 32 determines that no short circuit has occurred between the first counter electrode 11 and the second counter electrode 12 due to the metal foreign object F1. The determination unit 32 determines whether or not the first short circuit has occurred in the electrode sheet 5.

[0043] The time measurement unit 33 measures the detection time of the short circuit determined to have occurred by the determination unit 32. The time measurement unit 33 is, for example, a timer. The detection time is the time from a predetermined time point to the time point when the determination unit 32 determines that a short circuit has occurred. The above-mentioned predetermined time point may be, for example, the start time of the detection device 1 or the start time of the detection process for detecting the metal foreign object F1.

[0044] The display unit 34 is a display device capable of displaying various information, such as a liquid crystal display device. The display unit 34 displays the determination result of the determination unit 32 (the fact that the metal foreign object F1 has been detected) and the measurement time (detection time) of the time measurement unit 33.

[0045] The drive control unit 35 controls the drive mechanism 7 so that the roller 6 moves within the detection range 14 of the electrode sheet 5 over a predetermined time (e.g., 60 seconds) at regular intervals (e.g., 30 minutes). More specifically, the drive control unit 35 controls the drive mechanism 7 so that the roller 6 moves from the first end 14a to the second end 14b of the detection range 14 over the predetermined time, and after the predetermined time has elapsed, the roller 6 moves from the second end 14b to the first end 14a of the detection range 14 over the predetermined time (e.g., 60 seconds). Alternatively, the drive control unit 35 controls the drive mechanism 7 so that the roller 6 moves from the first end 14a to the second end 14b of the detection range 14 over the predetermined time, and after the movement, the roller 6 is quickly moved from the second end 14b back to the first end 14a, and after the predetermined time has elapsed, the roller 6 moves from the first end 14a to the second end 14b of the detection range 14 over the predetermined time.

[0046] (1-3) Applications of the detection device The detection device 1 can be used, for example, to detect metallic foreign matter F1 that is generated in the manufacturing process of lithium-ion batteries and scattered into the surroundings. More specifically, the manufacturing process of lithium-ion batteries includes an electrode process for forming electrode hoops for the positive or negative electrode of the lithium-ion battery. The electrode process includes a kneading process, a coating process, a compression process, and a cutting process. In the kneading process, an active material for the positive or negative electrode and a solvent (such as a binder) are mixed to prepare a slurry. In the coating process, the prepared slurry is applied onto a metal foil (electrode) and dried to form an electrode plate with an active material layer. In the compression process, the electrode plate with an active material layer is compressed to adjust its thickness. In the cutting process, a cutting device is used to cut the electrode plate with an active material layer, whose thickness has been adjusted, to a predetermined width.

[0047] In the cutting process, when the electrode plate with the active material layer is cut using a cutting device, chips (metal foreign matter F1) are generated and scattered around. The cutting condition of the cutting edge of the cutting device deteriorates over time. The smaller the cutting condition of the cutting edge, the gradually larger the size of the generated chips (metal foreign matter F1). That is, in the cutting process, as time elapses from the start of the cutting process, the size of the generated chips (metal foreign matter F1) gradually increases. For example, the size of the chips (metal foreign matter F1) is, for example, between a minimum of 5 μm and a maximum of 200 μm. Also, in the cutting process, the number of generated chips (metal foreign matter F1) is exponentially larger as the size becomes smaller.

[0048] The detection device 1 can be used, for example, by being arranged around the cutting device used in the cutting process to detect the chips (metal foreign matter F1) generated during the cutting of the cutting device and scattered and falling around. In this case, as described above, since the size of the generated chips (metal foreign matter F1) gradually increases over time, the size of the metal foreign matter F1 detected by the detection device 1 gradually increases over time. Thus, when the size of the metal foreign matter F1 to be detected gradually increases over time, the detection device 1 can detect the metal foreign matter F1 of a predetermined size (the same size as or slightly larger than the interval s1 between the first wiring electrode portion 11a and the second wiring electrode portion 12a) when the metal foreign matter F1 of the predetermined size begins to be generated. As will be described later, by adjusting the interval s1 between the first wiring electrode portion 11a and the second wiring electrode portion 12a, and the width w1 of the first wiring electrode portion 11a and the second wiring electrode portion 12a, it is possible to detect the metal foreign matter F1 of a desired size.

[0049] (1-4) Estimation of the optimal size of the metal foreign matter detectable. An estimation of the optimal size (i.e., the most easily detectable size) of the metal foreign matter F1 detectable by the pair of opposing electrodes 11 and 12 will be described.

[0050] In the following description, it is assumed that the generation frequency of the metal foreign matter F1 increases as the size of the metal foreign matter F1 decreases (i.e., the number of generated metal foreign matters F1 is exponentially larger as the size of the metal foreign matter F1 decreases).

[0051] As shown in Figure 3, when the size d1 of the metal foreign object F1 is smaller than the gap s1 (see Figure 3), the probability (short-circuit rate) P1 that the fallen metal foreign object F1 short-circuits the first wiring electrode section 11a and the second wiring electrode section 12a is given by Equation 1. Note that in the short-circuit rate P1, 100% is normalized to 1. Note that the size d1 of the metal foreign object F1 is the length of the longest part of the metal foreign object F1.

[0052] P1 = 0 ... Equation 1 Furthermore, when the size d1 of the metallic foreign object F1 is greater than or equal to the distance between adjacent first wiring electrode portions 11a (2 × s1 + w1) (see Figure 4, where Figure 4 shows the case where the size d1 is equal to the distance (2 × s1 + w1)), the short-circuit rate P1 is given by Equation 2.

[0053] P1 = 1 ... Equation 2 Furthermore, when the size d1 of the metallic foreign object F1 is greater than or equal to the spacing s1 and smaller than the spacing between adjacent first wiring electrode portions 11a (2 × s1 + w1) (see Figure 5), the short-circuit rate P1 is given by Equation 3.

[0054] P1 = (d1 - s1) / (s1 + w1) ... Equation 3 As shown above, when the number of metal foreign objects F1 changes, if a pair of opposing electrodes 11 and 12 having a spacing s1 and a width w1 are used, the number of detected metal foreign objects F1 will be maximized when the size d1 is between s1 and (2 × s1 + w1). The size d1 that takes this maximum value is the optimal size of metal foreign object F1 that can be detected by the pair of opposing electrodes 11 and 12.

[0055] We will calculate a specific example of the optimal size when s1 = 50 μm and w1 = 2 μm. In this case, the spacing between adjacent first wiring electrode portions 11a (2 × s1 + w1) is 102 μm. In this case, the relationship between the short-circuit rate P1 and the size d1 (foreign object size) of the metal foreign object F1 is calculated based on equations 1 to 3 and is shown in the graph in Figure 6. In this case, the relationship between the number of occurrences (number of foreign objects) and the average size of the metal foreign object F1 (average foreign object size) is shown in the graph in Figure 7 when actually measured. It can be seen that the number of foreign objects changes by an order of magnitude compared to the foreign object size. Also, in this case, from Figures 6 and 7, the relationship between the number of detected metal foreign objects F1 and the size d1 (foreign object size) of the metal foreign object F1 is shown in the graph in Figure 8. The number of detections in Figure 8 is obtained by multiplying the short-circuit rate in Figure 6 and the number of foreign objects in Figure 7. From Figure 8, it can be seen that the size d1 (i.e., the optimal size) for which the number of detected metal foreign objects F1 is maximized is 75 μm. As mentioned above, this optimal size is a value between s1 (= 50 μm) and 2 × s1 + w1 (= 102 μm).

[0056] The optimal size can be adjusted by changing the spacing s1 and width w1. In Embodiment 1, the spacing s1 and electrode width w1 of the pair of opposing electrodes 11 and 12 are set so that the optimal size is, for example, about 100 μm.

[0057] (1-5) The operation (detection method) of the detection device 1 will be explained with reference to the operation diagram 9.

[0058] The detection device 1 is installed in a predetermined location (for example, on the floor around a cutting device used in the cutting process of the lithium-ion battery manufacturing process). The time measurement unit 33 starts timing the detection time (ST1). Then, the drive mechanism 7 starts moving the roller 6 in conjunction with the start of timing by the time measurement unit 33 (ST2). More specifically, the drive mechanism 7 starts moving the roller 6 from one end 14a, 14b of the detection range 14 to the other.

[0059] Then, as the roller 6 moves, the measuring unit 31 starts measuring the resistance value between the first wiring electrode 11a and the second wiring electrode 12a (ST3). When the roller 6 moves over the metal foreign object F1 placed across the first wiring electrode 11a and the second wiring electrode 12a, the current flowing through the short circuit caused by the metal foreign object F1 between the first wiring electrode 11a and the second wiring electrode 12a improves, and the resistance value between the first wiring electrode 11a and the second wiring electrode 12a drops sharply to below the threshold.

[0060] The determination unit 32 determines whether or not a short circuit has occurred in the electrode sheet 5 based on the measurement result of the measurement unit 31 (ST4). More specifically, the determination unit 32 determines that a short circuit has occurred if the measurement result (resistance value) of the measurement unit 31 falls below a threshold, and determines that a short circuit has not occurred if the measurement result of the measurement unit 31 does not fall below the threshold. If the determination unit 32 does not determine that a short circuit has occurred in the electrode sheet 5 (ST4: No), the process proceeds to step ST5.

[0061] In step ST5, if the roller 6 has not moved to the other end of the detection range 14 and the movement of the roller 6 has not finished (ST5: No), the process returns to step ST4. On the other hand, if the roller 6 has moved to the other end of the detection range 14 and the movement of the roller 6 has finished (ST5: Yes), the process waits for a certain amount of time to elapse since the end of the movement of the roller 6 in step ST5 (ST6), and then the process returns to step ST2.

[0062] On the other hand, if the determination unit 32 determines that a short circuit has occurred as a result of the determination in step ST4 (ST4: Yes), the time measurement unit 33 measures the time (detection time) from the start of timing in step ST1 to the determination point in step ST4 (ST7). The drive mechanism 7 then stops moving the roller 6 when the roller 6 has moved to the other end of the detection range 14 (ST8). The display unit 34 then displays the determination result of the determination unit 32 (that a metal foreign object F1 of a predetermined size has been detected) and the measurement result of the time measurement unit 33 (detection time) (ST9). The process then ends.

[0063] Thus, when the detection device 1 detects one metallic foreign object F1 of a predetermined size (for example, about 100 μm), the manufacturing process of the lithium-ion battery may be stopped, for example, and the various devices used in the manufacturing process may be maintained.

[0064] (1-6) The detection device 1 according to the first embodiment of the effect comprises an electrode sheet 5 and a measuring unit 31. The electrode sheet has a pair of counter electrodes 11 and 12 and an insulating sheet 13. The pair of counter electrodes 11 and 12 include a first counter electrode 11 and a second counter electrode 12. The insulating sheet 13 supports the pair of counter electrodes 11 and 12. The first counter electrode has a plurality of first wiring electrode portions 11a, and the second counter electrode 12 has a plurality of second wiring electrode portions 12a. The plurality of second wiring electrode portions 12a are arranged alternately with the plurality of first wiring electrode portions 11a at intervals s1. The measuring unit 31 measures the electrical value between the pair of counter electrodes 11 and 12. The determination unit 32 determines, based on the measurement result of the measuring unit 31, whether or not a short circuit has occurred between the pair of counter electrodes 11 and 12 due to a metallic foreign object F1 falling in the atmosphere.

[0065] This configuration allows for the detection of metallic foreign objects F1 falling through the atmosphere. More specifically, it allows for the detection of metallic foreign objects F1 of a size corresponding to the distance s1 between the first wiring electrode portion 11a and the second wiring electrode portion 12a.

[0066] Furthermore, the detection device 1 according to Embodiment 1 further comprises a roller 6 and a drive mechanism 7. The roller 6 is insulating. The roller 6 moves across the detection range 14 of the pair of opposing electrodes 11 and 12. The drive mechanism 7 moves the roller 6 across the detection range 14 of the pair of opposing electrodes 11 and 12 at regular intervals.

[0067] With this configuration, the roller 6 passes through the detection range 14, improving the current flow state of the short circuit between the pair of opposing electrodes 11 and 12 caused by the metal foreign object F1. As a result, the metal foreign object F1 that has fallen onto the electrode sheet 5 can be detected more reliably.

[0068] Furthermore, the detection device 1 according to Embodiment 1 further includes a time measuring unit 33. The time measuring unit 33 measures the detection time of a short circuit determined to have occurred by the determination unit 32. The detection time is the time from a predetermined point in time to the point in time when the determination unit 32 determines that a short circuit has occurred. With this configuration, the detection time, which is the time until a metal foreign object F1 is detected, can be measured.

[0069] Furthermore, in the detection device 1 according to Embodiment 1, the first main surface 13a (main surface) of the insulating sheet 13 has a first recess 131 and a second recess 132. The first recess 131 is fitted with the first opposing electrode 11. The second recess 132 is fitted with the second opposing electrode 12. The exposed surface 11u (first exposed surface) of the first opposing electrode 11 is located at the same height as the first main surface 13a of the insulating sheet 13 or at a lower height than the main surface 13a. The exposed surface 12u (second exposed surface) of the second opposing electrode 12 is located at the same height as the first main surface 13a of the insulating sheet 13 or at a lower height than the main surface 13a.

[0070] With this configuration, the current flow state of the short circuit between the pair of opposing electrodes 11 and 12 caused by the metal foreign object F1 can be improved only while the roller 6 is moving over the metal foreign object F1. Therefore, the location of the short circuit can be distinguished by the position of the roller 6.

[0071] Furthermore, in the detection device 1 according to Embodiment 1, the drive mechanism 7 comprises a drive unit 71 and a guide unit 72. The drive unit 71 moves the roller 6. The guide unit 72 moves the roller 6 in the first direction T1. With this configuration, the mechanism for moving the roller 6 can be easily constructed.

[0072] Furthermore, in the detection device 1 according to Embodiment 1, the detection device 1 is positioned around a cutting device that cuts electrode plates, which are the material for the electrodes of a lithium-ion battery. With this configuration, it is possible to detect metallic foreign matter F1 that is generated in the manufacturing process of lithium-ion battery electrode plates.

[0073] (1-7) Functions similar to those of the detection device 1 according to Embodiment 1 may be embodied in a detection method, a computer program (program), or a non-temporary recording medium on which a computer program is recorded.

[0074] A detection method according to one embodiment includes a measurement step ST3 and a determination step ST4. In the measurement step ST3, the electrical value between a pair of opposing electrodes 11 and 12 of the electrode sheet 5 is measured. The electrode sheet 5 has a pair of opposing electrodes 111 and 12 and an insulating sheet 13. The pair of opposing electrodes 11 and 12 include a first opposing electrode 11 and a second opposing electrode 12. The first opposing electrode 11 has a plurality of first wiring electrode portions 11a, and the second opposing electrode 12 has a plurality of second wiring electrode portions. The plurality of second wiring electrode portions 12a are arranged with a distance s1 between them from the plurality of first wiring electrode portions 11a. The insulating sheet 13 supports the pair of opposing electrodes 11 and 12. In the determination step ST4, based on the measurement result of the measurement step ST3, it is determined whether or not a short circuit has occurred between the pair of opposing electrodes 11 and 12 due to a metallic foreign object F1 falling in the atmosphere.

[0075] A program according to one embodiment causes one or more processors to execute the above-described detection method.

[0076] A non-temporary recording medium according to one embodiment records a program that causes one or more processors to execute the above-described detection method.

[0077] (1-8) Modifications of Embodiment 1 are listed below. The modifications described below can be applied in appropriate combinations.

[0078] (1-8-1) Modification 1 Embodiment 1 illustrates a case where a roller 6, a drive mechanism 7, and a drive control unit 35 are provided. However, the roller 6, drive mechanism 7, and drive control unit 35 are not required. If the roller 6, drive mechanism 7, and drive control unit 35 are not provided, contact between the metal foreign object F1 and the first wiring electrode portion 11a and the second wiring electrode portion 12a is ensured by the weight of the metal foreign object F1. In this case, even if the metal foreign object F1 causes a short circuit between the first counter electrode 11 and the second counter electrode 12, the current flow state of the short circuit between the first counter electrode 11 and the second counter electrode 12 may not change as much as in Embodiment 1. However, as in Embodiment 1, it is possible to determine whether or not a short circuit has occurred by comparing the measured electrical value with a threshold value.

[0079] (1-8-2) Modification 2 In Embodiment 1, the exposed surfaces 11u and 12u of the first opposing electrode 11 and the second opposing electrode 12 on the electrode sheet 5 are at the same height as the first main surface 13a of the insulating sheet 13 (see Figure 2). However, the exposed surfaces 11u and 12u of the first opposing electrode 11 and the second opposing electrode 12 may be lower than the first main surface 13a of the insulating sheet 13. In this case, when the roller 6 moves over the metallic foreign matter F1 present on the insulating sheet 13, the roller 6 elastically compresses the insulating sheet 13 in the thickness direction via the metallic foreign matter F1. As a result, the first main surface 13a of the insulating sheet 13 becomes at the same height as the first opposing electrode 11 and the second opposing electrode 12. As a result, the metallic foreign matter F1 short-circuits across the space between the first opposing electrode 11 and the second opposing electrode 12. Then, when the roller 6 passes over the metal foreign object F1, the thickness of the insulating sheet 13 elastically returns to its original thickness, and the first main surface 13a of the insulating sheet 13 becomes higher than the exposed surfaces 11u and 12u of the first and second opposing electrodes 11 and 12u. As a result, the short circuit between the metal foreign object F1 and the first wiring electrode portion 11a and the second wiring electrode portion 12a is released.

[0080] (2) Embodiment 2 The detection device 1 according to Embodiment 2 will be described with reference to Figures 10 and 11.

[0081] (2-1) As shown in the configuration diagram 10, the detection device 1 according to Embodiment 2 is configured similarly to the detection device 1 according to Embodiment 1, except that it further comprises multiple pairs (only two are shown in the example of Figure 10) of counter electrodes 11, 12, multiple (only two are shown in Figure 10) of measuring units 31, multiple (only two are shown in the example of Figure 10) of determination units 32, and a counting unit 37. The detection device 1 according to Embodiment 2 is capable of detecting multiple (the same number as the number of pairs of counter electrodes 11, 12) of metal foreign objects F1 of a predetermined size.

[0082] In the following description, components identical to those in Embodiment 1 are denoted by the same reference numerals and their descriptions are omitted. In some cases, the description will focus on components that differ from those in Embodiment 1.

[0083] The detection device 1 according to Embodiment 2 comprises an electrode sheet section 2 and a detection circuit section 3, similar to the detection device 1 according to Embodiment 1.

[0084] The electrode sheet portion 2 of Embodiment 2 comprises an electrode sheet 5, a roller 6, and a drive mechanism 7, similar to the electrode sheet portion 2 of Embodiment 1. Since the roller 6 and drive mechanism 7 of Embodiment 2 are configured similarly to those of Embodiment 1, a detailed explanation is omitted. The electrode sheet 5 of Embodiment 2 is configured similarly to the electrode sheet 5 of Embodiment 1, except that it has multiple pairs (two in the example of Figure 10) of opposing electrodes 11 and 12.

[0085] Each of the multiple pairs of opposing electrodes 11, 12 is configured similarly to the pair of opposing electrodes 11, 12 in Embodiment 1. The spacing s1 between each of the multiple pairs of opposing electrodes 11, 12 (i.e., the spacing between the first wiring electrode portion 11a and the second wiring electrode portion 12a) is the same size. The multiple pairs of opposing electrodes 11, 12 are arranged in a direction perpendicular to the direction of movement T1 of the roller 6 (see Figure 10). However, the multiple pairs of opposing electrodes 11, 12 may be arranged in a direction parallel to the direction of movement T1 of the roller 6. Each of the insulating sheets 13 of the multiple electrode sheets 5 is formed integrally. However, each of the insulating sheets 13 of the multiple electrode sheets 5 does not have to be formed integrally.

[0086] The detection circuit unit 3 of Embodiment 2 is configured similarly to the detection circuit unit 3 of Embodiment 1, except that it has a plurality of measurement units 31 and a plurality of determination units 32.

[0087] Multiple measuring units 31 correspond one-to-one with multiple pairs of counter electrodes 11, 12, and measure the electrical value (e.g., resistance value) between the corresponding pairs of counter electrodes 11, 12.

[0088] Multiple determination units 32 correspond one-to-one with multiple measurement units 31. Multiple determination units 32 correspond to the corresponding measurement unit 31 and the corresponding pair of counter electrodes 11, 12. Based on the measurement results of the corresponding measurement unit 31, the multiple determination units 32 determine whether or not a short circuit (i.e., the first short circuit) has occurred between the corresponding pair of counter electrodes 11, 12.

[0089] The counting unit 37 counts the number of times a short circuit occurs in the electrode sheet 5 (i.e., the number of times a metal foreign object F1 of a predetermined size occurs) based on the determination results of the multiple determination units 32.

[0090] The time measurement unit 33 is configured in the same way as the time measurement unit 33 in Embodiment 1. The time measurement unit 33 measures the detection time of a short circuit determined to have occurred by each determination unit 32. That is, for a short circuit determined to have occurred by each determination unit 32, the time measurement unit 33 measures the time (detection time) from a predetermined time (when the detection device 1 is started or when detection begins) to the time when the determination unit 32 determines that a short circuit has occurred.

[0091] Furthermore, if there are multiple counting results (number of short circuits) from the counting unit 37, the time measurement unit 33 calculates the average value of the detection time for each short circuit counted by the counting unit 37 (average detection time).

[0092] The display unit 34 is configured in the same way as the display unit 34 in Embodiment 1. The display unit 34 displays one or more (for example, all) of the following: the counting result of the counting unit 37 (number of short circuits), the detection time of each short circuit counted by the counting unit 37, and the average detection time.

[0093] The detection device 1 according to Embodiment 2 includes a plurality of pairs of counter electrodes 11, 12 having the same spacing s1 between them. A pair of counter electrodes 11, 12 can detect one short circuit (the first short circuit). Therefore, the detection device 1 according to Embodiment 2 can detect a plurality of metal foreign objects F1 of a predetermined size (the same number as the plurality of pairs of counter electrodes 11, 12).

[0094] (2-2) The operation (detection method) of the detection device 1 according to Embodiment 2 will be explained with reference to the operation diagram 11. In Figure 11, steps ST1 to ST7 are the same as steps ST1 to ST7 in the operation explanation of Embodiment 2 (see Figure 9), so the explanation will be omitted, and the explanation will focus on steps ST81 to ST84 from step ST7 onward.

[0095] In Embodiment 2, after the processing in step ST7, the process proceeds to step ST81. In step ST81, the counting unit 37 counts the occurrences of short circuits that were determined to have occurred in step ST4. If there are multiple occurrences of short circuits (ST82: Yes), the counting unit 37 calculates the average value of the detection times of the counted short circuits (average detection time) (ST83). Then the process proceeds to step ST84. On the other hand, if there are not multiple occurrences of short circuits (ST82: No), the counting unit 37 omits step ST83 and proceeds to step ST84. In step ST84, the display unit 34 displays at least one of the counting results of the counting unit 37 (number of short circuits), the detection time of each counted short circuit, and the average detection time. Then the process proceeds to step ST5, and the process from step ST5 onward is repeated. When the first short circuit occurs in all of the multiple electrode sheets 5, the determination unit 32 no longer detects short circuits by determination, and the process is effectively terminated.

[0096] (2-3) Applications of the detection device The detection device 1 can count the number of metal foreign objects F1 of a predetermined size that fall into the atmosphere. Therefore, it is possible to use the detection device 1 to confirm whether a predetermined number of metal foreign objects F1 of a predetermined size have been detected. As a result, for example, in the lithium-ion manufacturing process, if a predetermined number of metal foreign objects F1 of a predetermined size are detected, maintenance of the various devices used in the manufacturing process can be performed to prevent the generation of metal foreign objects F1 larger than the predetermined size.

[0097] (2-4) In the detection device 1 according to the second embodiment of the effect, the electrode sheet 5 has a plurality of pairs of counter electrodes 11, 12. The spacing s1 between each of the plurality of pairs of counter electrodes 11, 12 is the same. The detection device 1 comprises a plurality of measuring units 31, a plurality of determination units 32, and a counting unit 37. The plurality of measuring units 31 correspond to the plurality of pairs of counter electrodes 11, 12 and measure the electrical value between the corresponding pairs of counter electrodes 11, 12. The plurality of determination units 32 correspond to the plurality of measuring units 31 and determine whether or not a short circuit has occurred between the corresponding pairs of counter electrodes 11, 12 based on the measurement results of the corresponding measuring units 31. The counting unit 37 counts the number of times a short circuit has occurred in the electrode sheet 5 based on the determination results of the plurality of determination units 32.

[0098] With this configuration, by providing multiple pairs of opposing electrodes 11 and 12, it is possible to detect multiple (the same number as the multiple pairs) metal foreign objects F1 of a predetermined size.

[0099] (3) Embodiment 3 The detection device 1 according to Embodiment 3 will be described with reference to Figures 12 and 13.

[0100] (3-1) As shown in the configuration diagram 12, the detection device 1 according to embodiment 3 is configured to detect a plurality of metal foreign objects F1 of a predetermined size using a pair of opposing electrodes 11 and 12.

[0101] More specifically, the detection device 1 according to Embodiment 3 comprises an electrode sheet section 2 and a detection circuit section 3. The electrode sheet section 2 is configured in the same way as the electrode sheet section 2 of Embodiment 1. The detection circuit section 3 is configured similarly to the detection circuit section 3 of Embodiment 1, except that it further includes a position measuring section 36 and a counting section 37.

[0102] The electrode sheet section 2 and the detection circuit section 3, excluding the position measuring section 36 and the counting section 37, are configured in the same way as in Embodiment 1. Therefore, the following description will focus on the position measuring section 36 and the counting section 37, and descriptions of the other components may be omitted.

[0103] In Embodiment 3, when the roller 6 moves over the metal foreign object F1 while it is positioned between the pair of opposing electrodes 11 and 12 of the electrode sheet 5, the roller 6 presses the metal foreign object F1 against the pair of opposing electrodes 11 and 12 only while it is over the metal foreign object F1. As a result, the short-circuit state between the pair of opposing electrodes 11 and 12 caused by the metal foreign object F1 is improved only while the roller 6 is over the metal foreign object F1, and the electrical resistance value between the pair of opposing electrodes 11 and 12 decreases rapidly. When the roller 6 passes over the metal foreign object F1, the improvement in the short-circuit state between the pair of opposing electrodes 11 and 12 caused by the metal foreign object F1 ceases, and the electrical resistance value between the pair of opposing electrodes 11 and 12 increases again. Therefore, in Embodiment 3, it is possible to identify the position of the roller 6 when the electrical resistance value (electrical numerical value) decreases (changes) rapidly as the position of the short circuit. As a result, in Embodiment 3, the position of the roller 6 makes it possible to distinguish the location of the short circuit, and thus it is possible to detect multiple short circuits with the pair of opposing electrodes 11 and 12.

[0104] The measuring unit 31 measures the electrical value (e.g., electrical resistance value) between the pair of opposing electrodes 11 and 12 of the electrode sheet 5, similar to the measuring unit 31 of Embodiment 1.

[0105] The position measuring unit 36 ​​measures the position of the roller 6 on the electrode sheet 5. The position of the roller 6 is, for example, the position between the first end 14a and the second end 14b within the detection range 14 of the electrode sheet 5. More specifically, the position measuring unit 36 ​​measures the time from the start of the movement of the roller 6 and measures the position of the roller 6 based on the length of this measured time. For example, when moving the roller 6 from one end 14a, 14b of the detection range 14 to the other end, the time from the start of the movement of the roller 6 from the aforementioned end is measured. Since the movement speed of the roller 6 is constant, it is possible to measure the position of the roller 6 by the measured time.

[0106] The determination unit 32, similar to the determination unit 32 in Embodiment 1, determines whether or not a short circuit has occurred between the pair of counter electrodes 11 and 12 due to the metallic foreign object F1, based on the measurement results of the measurement unit 31. More specifically, the determination unit 32 determines whether or not a short circuit has occurred depending on whether or not the measurement result (electrical resistance value) of the measurement unit 31 falls below a threshold. For example, if the measurement result is not below the threshold, the determination unit 32 determines that no short circuit has occurred, and if the measurement result falls below the threshold, it determines that a short circuit has occurred.

[0107] More specifically, the determination unit 32 identifies the location of the short circuit at the time of determination based on the measurement result of the position measurement unit 36 ​​at the time of determination. The determination unit 32 then validates the determination result if the identified short circuit location is not the same as a previously identified short circuit location (i.e., it is a short circuit at a new location). In other words, the determination unit 32 ultimately determines that a short circuit occurred at the identified location. On the other hand, the determination unit 32 invalidates the determination result if the identified short circuit location is the same as a previously identified short circuit location (i.e., it is not a short circuit at a new location). In other words, the determination unit 32 ultimately determines that no short circuit occurred at the identified location. Hereafter, this process of determining whether or not a short circuit location is a new location will be referred to as the short circuit location determination process.

[0108] The determination unit 32 determines the occurrence of a short circuit, as described above, by relating it to the measurement result of the position measurement unit 36 ​​at the time of determination (the position of the roller 6, i.e., the position of the short circuit).

[0109] The time measurement unit 33 is configured in the same way as the time measurement unit 33 in Embodiment 1, and measures the detection time of a short circuit determined to have occurred by the determination unit 32. More specifically, the time measurement unit 33 measures the detection time of a short circuit in correspondence with the measurement result of the position measurement unit 36 ​​at the time of determination by the determination unit 32 (the position of the roller 6, i.e., the position of the short circuit). Furthermore, if there are multiple counting results (number of short circuit occurrences) from the counting unit 37 described later, the time measurement unit 33 calculates the average value (average detection time) of the detection times of the short circuits determined to have occurred by the determination unit 32.

[0110] The counting unit 37 counts the number of short circuits that have occurred in the electrode sheet 5 based on the determination result of the determination unit 32. In other words, the counting unit 37 counts the number of short circuits that have been determined to have occurred by the determination unit 32.

[0111] The display unit 34 is configured similarly to the display unit 34 of Embodiment 1, and displays at least one of the following: the counting result of the counting unit 37 (number of short circuits), the detection time of each short circuit counted by the counting unit 37, and the average detection time.

[0112] In the detection device 1 according to Embodiment 3, by using a roller 6, it is possible to detect multiple metal foreign objects F1 of a predetermined size using a pair of opposing electrodes 11 and 12.

[0113] (3-2) The operation (detection method) of the detection device 1 will be explained with reference to the operation diagram 13.

[0114] The detection device 1 is installed in a predetermined location (for example, on the floor around a cutting device used in the cutting process of the lithium-ion battery manufacturing process). The time measurement unit 33 starts timing the detection time (ST21). Then, the drive mechanism 7 starts moving the roller 6 in conjunction with the start of timing by the time measurement unit 33 (ST22). More specifically, the drive mechanism 7 starts moving the roller 6 from one end 14a, 14b of the detection range 14 to the other. Also, the position measurement unit 36 ​​starts measuring the position of the roller 6 in conjunction with the start of the roller 6's movement (ST23). Also, the measurement unit 31 starts measuring the resistance value (electrical value) between the first wiring electrode section 11a and the second wiring electrode section 12a in conjunction with the start of the roller 6's movement (ST24). As the roller 6 moves over the metal foreign object F1 positioned between the first wiring electrode section 11a and the second wiring electrode section, the short-circuit state between the first wiring electrode section 11a and the second wiring electrode section 12a caused by the metal foreign object F1 is improved, and the resistance value between the first wiring electrode section 11a and the second wiring electrode section 12a drops sharply to below the threshold.

[0115] The determination unit 32 determines whether or not a short circuit has occurred in the electrode sheet 5 based on the measurement result of the measurement unit 31 (ST25). More specifically, the determination unit 32 determines that no short circuit has occurred if the measurement result of the measurement unit 31 is not below a threshold. Also, the determination unit 32 determines that a short circuit has occurred if the measurement result of the measurement unit 31 falls below a threshold. More specifically, the determination unit 32 identifies the location of the short circuit based on the measurement result of the position measurement unit 36 ​​(position of the roller 6) at the time of determination. If the identified location of the short circuit is the same as a previously identified location of the short circuit, the determination result is invalidated, and the determination unit 32 ultimately determines that no short circuit has occurred. Also, if the identified location of the short circuit is not the same as a previously identified location of the short circuit, the determination result is valid, and the determination unit 32 associates it with the identified location of the short circuit and ultimately determines that a short circuit has occurred. If the determination unit 32 ultimately determines that no short circuit has occurred (ST25: No), the process proceeds to step ST26.

[0116] In step ST26, if the roller 6 has not moved to the other end of the detection range 14 and the movement of the roller 6 has not finished (ST26: No), the process returns to step ST25. On the other hand, if the roller 6 has moved to the other end of the detection range 14 and the movement of the roller 6 has finished (ST26: Yes), the position measuring unit 36 ​​finishes measuring the position of the roller 6 (ST27). Then, after waiting for a certain amount of time to elapse since the end of the movement of the roller 6 in step ST26 (ST28), the process returns to step ST22.

[0117] On the other hand, if the determination unit 32 determines, based on the result of the determination in step ST25, that a short circuit has occurred (ST25: Yes), then the time measurement unit 33 measures the time (detection time) from the start of timing in step ST21 to the determination point in step ST25 (ST29). More specifically, the time measurement unit 33 measures the position of the roller 6 at the time of the determination in step ST25 based on the timing result of step ST23, and measures the detection time in correspondence with the measured position of the roller (i.e., the position of the short circuit).

[0118] Then, the counting unit 37 counts the number of short circuits that have occurred in the electrode sheet 5 based on the determination result of the determination unit 32 in step ST25 (ST30). More specifically, the counting unit 37 counts the number of short circuits that have been determined to have occurred by the determination unit 32.

[0119] Then, if the number of short circuits is multiple (ST31: Yes), the counting unit 37 calculates the average value of the detection time for each short circuit (average detection time) (ST32). Then, the process proceeds to step ST33. On the other hand, if the number of occurrences is not multiple (ST31: No), the counting unit 37 skips step ST32 and proceeds to step ST33. In step ST33, the display unit 34 displays at least one of the counting results from the counting unit 37 (number of short circuits), the detection time for each short circuit, and the average detection time. Then, the process proceeds to step ST26, and the process from step ST26 onward is repeated.

[0120] (3-3) Applications of the detection device The detection device 1 according to Embodiment 3 can count the number of metal foreign objects F1 of a predetermined size that fall into the atmosphere, similar to the detection device 1 according to Embodiment 2. For this reason, for example, in a lithium-ion manufacturing process, if a predetermined number of metal foreign objects F1 of a predetermined size are detected, the various devices used in the manufacturing process can be maintained to prevent the generation of metal foreign objects F1 larger than the predetermined size.

[0121] (3-4) The detection device 1 according to the third embodiment of the effect comprises a roller 6, a drive mechanism 7, and a counting unit 37. The roller 6 is insulating. The roller 6 moves across the detection range 14 of the pair of opposing electrodes 11 and 12. The drive mechanism 7 moves the roller 6 across the detection range 14 of the pair of opposing electrodes 11 and 12 at regular intervals. The counting unit 37 counts the number of times a short circuit occurs in the electrode sheet 5 based on the determination result of the determination unit 32.

[0122] With this configuration, multiple metallic foreign objects F1 can be detected by a pair of counter electrodes 11 and 12. Because a pair of counter electrodes 11 and 12 are used, the number of measurement units and determination units 32 is reduced to the number of the pair of counter electrodes 11 and 12 (i.e., one unit), resulting in cost reduction and miniaturization.

[0123] Furthermore, the detection device 1 according to Embodiment 3 includes a position measuring unit 36. The position measuring unit 36 ​​measures the position of the roller 6 within the detection range 14 of the pair of opposing electrodes 11 and 12. The determination unit 32 identifies the location of the short circuit determined to have occurred using the measurement result of the position measuring unit 36 ​​at the time of determination. If the identified short circuit location is not the same as a previously identified short circuit location, the determination result of the determination unit 32 is made valid. If the identified short circuit location is the same as a previously identified short circuit location, the determination result of the determination unit 32 is made invalid. With this configuration, the position measuring unit 36 ​​can accurately distinguish whether an generated short circuit is a previously identified short circuit or not.

[0124] (3-5) Modifications of Embodiment 3 are listed below. The modifications described below can be combined and applied as appropriate.

[0125] (3-5-1) Modification 1 In Embodiment 3, the position measuring unit 36 ​​measures the time from the start of movement of the roller 6 and measures the position of the roller 6 by the length of the measured time. However, instead of using the measured time, the position measuring unit 36 ​​may measure the position of the roller 6 using the rotation speed or rotation angle of the roller 6, or it may measure the distance of the roller 6 from a predetermined position (for example, the first end 14a or the second end 14b of the detection range 14) using a distance measuring sensor and measure the position of the roller 6 by the measured distance.

[0126] (3-5-2) Modification 2 In Embodiment 3, the short-circuit location determination process of the determination unit 32 may be performed by an external processing unit. In this case, the detection circuit unit 3 further includes a communication unit that performs data communication with the external processing unit. The detection circuit unit 3 transmits the measurement value of the position measuring unit 36 ​​at the time the determination unit 32 determines that a short circuit has occurred to the external processing unit via the communication unit. The external processing unit stores the received measurement value in a storage unit. Based on the received measurement value, the external processing unit identifies the location of the short circuit determined to have occurred by the determination unit 32, and determines whether the identified location of the short circuit is the first location, depending on whether the identified location is the same as a short circuit already identified. The external processing unit then transmits the determination result to the detection circuit unit 3 via the communication unit. In the detection circuit unit 3, the counting unit 37 counts the short circuit as the occurrence count only if the location of the short circuit determined to have occurred by the determination unit 32 is the first location, based on the determination result from the external processing unit.

[0127] In this way, by having an external processing unit perform the short-circuit location determination process, the processing load on the detection circuit unit 3 can be reduced. Furthermore, by using an external processing unit with higher performance, the short-circuit location determination process can be performed more quickly.

[0128] (3-5-3) Modification 3 In Embodiment 3, if it can be assumed that all short circuits occur at different roller positions, it is not necessary to identify the location of the short circuits based on the measurement results (roller positions) of the position measuring unit 36, and therefore the position measuring unit 36 ​​may be omitted. In this case, the determination unit 32 processes all short circuits that it has determined to have occurred as occurring at different positions.

[0129] (4) Embodiment 4 A prediction device 100 according to Embodiment 4 will be described with reference to Figures 14 and 15.

[0130] (4-1) The prediction device 100 according to the configuration embodiment 4 predicts the detection time of a metal foreign object F1 of a predetermined size falling through the atmosphere. The detection time is the time from a predetermined point in time until the metal foreign object is detected. The prediction device 100 is configured using the detection device 1 of the embodiment 1. In the following description, components that are the same as those in the detection device 1 of the embodiment 1 are denoted by the same reference numerals and their descriptions are omitted, and the description may focus on components that are different from the detection device 1.

[0131] The prediction device 100 assumes that the size of metal foreign objects F1 falling into the atmosphere gradually increases over time (Assumption 1). It also assumes that the number of metal foreign objects F1 increases exponentially as their size decreases (Assumption 2). Note that Assumption 2 is not a mandatory assumption and can be omitted.

[0132] As shown in Figure 14, the prediction device 100 comprises an electrode sheet section 102 and a detection circuit section 103.

[0133] (4-1-1) Electrode Sheet Section The electrode sheet section 102 of Embodiment 4 captures multiple metal foreign objects F1 of different sizes that fall in the atmosphere. As shown in Figure 14, the electrode sheet section 102 of Embodiment 4 includes an electrode sheet 5, a roller 6, and a drive mechanism 7, similar to the electrode sheet section 2 of Embodiment 1.

[0134] The electrode sheet 5 of Embodiment 4 is configured similarly to the electrode sheet 5 of Embodiment 1 (see Figure 1), except that the electrode sheet 5 has multiple pairs of counter electrodes 11 and 12 (five pairs G1 to G5 in the example of Figure 14). That is, the electrode sheet 5 of Embodiment 4 has multiple pairs G1 to G5 of counter electrodes 11 and 12. The multiple pairs G1 to G5 of counter electrodes 11 and 12 are configured similarly to the pair of counter electrodes 11 and 12 of Embodiment 1. The spacing s1 between each of the multiple pairs G1 to G5 of counter electrodes 11 and 12 (i.e., the spacing between the first wiring electrode portion 11a and the second wiring electrode portion 12a) is different from one another.

[0135] The first main surface 13a of the insulating sheet 13 in Embodiment 4 has a plurality of first recesses 131 and a plurality of second recesses 132 (see Figure 14). The plurality of first recesses 131 correspond one-to-one with a plurality of pairs G1 to G5, and the corresponding pairs of first opposing electrodes 11 are fitted into and arranged therein. The plurality of first recesses 131 are formed in the same way as the first recesses 131 in Embodiment 1. Therefore, when the exposed surfaces 11u of the plurality of pairs G1 to G5 first opposing electrodes 11 are fitted into the corresponding first recesses 131, they are positioned at the same height as the first main surface 13a of the insulating sheet 13 or at a lower height than the first main surface 13a (see Figure 2). Also, when the exposed surfaces 12u of the plurality of pairs G1 to G5 second opposing electrodes 12 are fitted into the corresponding second recesses 132, they are positioned at the same height as the first main surface 13a of the insulating sheet 13 or at a lower height than the first main surface 13a (see Figure 2).

[0136] When distinguishing between the intervals s1 of multiple pairs G1 to G5, the interval s1 of pair G1 may be described as interval s11, the interval s1 of pair G2 as interval s12, the interval s1 of pair G3 as interval s13, the interval s1 of pair G4 as interval s14, and the interval s1 of pair G5 as interval s15. The relative sizes of the intervals s1 of each pair G1 to G5 are, for example, in the order of interval s11, interval s12, interval s13, interval s14, and interval s15.

[0137] The spacing s11 between the counter electrodes 11 and 12 for G1 to G5 is set such that the optimal size of metallic foreign matter detectable by the counter electrodes 11 and 12 for G1 to G5 is, for example, about 10 μm, 20 μm, 40 μm, 70 μm, and 100 μm.

[0138] Since the roller 6 and drive mechanism 7 of Embodiment 4 have the same configuration as the roller 6 and drive mechanism 7 of Embodiment 1, a detailed explanation will be omitted.

[0139] Each of the multiple pairs of counter electrodes 11 and 12 (G1 to G5) captures a metallic foreign object F1 of a size (e.g., an optimal size) corresponding to the interval s1 specific to each pair of G1 to G5. Therefore, the multiple pairs of counter electrodes 11 and 12 (G1 to G5) capture multiple metallic foreign objects of different sizes.

[0140] (4-1-2) Detection Circuit The detection circuit 103 predicts the detection time of a larger predetermined size (for example, about 100 μm) of metal foreign matter F1 based on the correlation between the size and detection time of a plurality of metal foreign matter F1 of different sizes (for example, about 10 μm to 70 μm) captured by the electrode sheet 102. As shown in Figure 14, the detection circuit 103 of Embodiment 4 is configured similarly to the detection circuit 3 of Embodiment 1, except that it includes a plurality of measurement units 31, a plurality of determination units 32, and a prediction unit 40. That is, the detection circuit 103 of Embodiment 4 includes a plurality of (five in the example of Figure 14) measurement units 31, a plurality of (five in the example of Figure 14) determination units 32, a time measurement unit 33, a display unit 34, a drive control unit 35, and a prediction unit 40.

[0141] Multiple measuring units 31 correspond one-to-one with multiple pairs of counter electrodes 11, 12, and measure the electrical value (e.g., resistance value) between the corresponding pairs of counter electrodes 11, 12.

[0142] Each of the multiple determination units 32 corresponds one-to-one with each of the multiple measurement units 31. Therefore, each of the multiple determination units 32 also corresponds to the corresponding measurement unit 31 and the corresponding pair of counter electrodes 11 and 12. Based on the measurement results of the corresponding measurement unit 31, each determination unit 32 determines whether or not a short circuit has occurred between the corresponding pair of counter electrodes 11 and 12. More specifically, each determination unit 32 determines whether or not a short circuit has occurred depending on whether or not the measurement result (resistance value) of the corresponding measurement unit 31 falls below a threshold.

[0143] In Embodiment 4, when the first short circuit occurs at each pair of counter electrodes 11 and 12 of G1 to G5, subsequent short circuits cannot be distinguished from the first short circuit, so only the first short circuit is detected by the determination unit. In other words, each determination unit 32 detects only the first short circuit at the corresponding pair of counter electrodes 11 and 12 by determination.

[0144] The time measurement unit 33 measures the detection time of a short circuit (a short circuit caused by a metal foreign object F1 smaller than a predetermined size) that has been determined to have occurred by each determination unit 32. The detection time of a short circuit is, as described in Embodiment 1, the time from a predetermined point in time (when the prediction device is started or when short circuit detection begins) to the point in time when the determination unit 32 determines that a short circuit has occurred (i.e., the point in time when the metal foreign object F1 is detected). More specifically, for each short circuit that has been determined to have occurred by each determination unit 32, the time measurement unit 33 measures the time from a predetermined point in time to the point in time when the determination unit 32 determines that a short circuit has occurred (detection time).

[0145] The prediction unit 40 predicts the detection time for a short circuit caused by a metal foreign object F1 of a predetermined size (the detection time for a metal foreign object F1 of a predetermined size).

[0146] More specifically, the prediction unit 40 determines the correspondence between the interval s1 (foreign object size) and the detection time for each of two or more predetermined pairs (e.g., G1 to G4) from among multiple pairs G1 to G5, where the interval s1 is smaller than a predetermined size. Then, based on the determined correspondence, the prediction unit 40 determines the correlation between the interval s1 and the detection time (e.g., the correlation diagram and correlation line L1 described later). Then, based on the determined correlation, the prediction unit 40 predicts the detection time for a short circuit caused by the metal foreign object F1 of the predetermined size.

[0147] More specifically, the prediction unit 40 determines, based on the determination results of each determination unit 32, whether or not a short circuit has occurred in each of the predetermined number of pairs of G1 to G4 opposing electrodes 11 and 12.

[0148] The "determined number of pairs" mentioned above is set in advance and, as described above, is, for example, four pairs G1 to G4. In Embodiment 4, it is assumed that the interval s1 between each of the four pairs G1 to G4 is smaller than a predetermined size. In Embodiment 4, each determination unit 32 detects only the first short circuit at the corresponding pair's counter electrodes 11 and 12 by determination. Therefore, "whether or not a short circuit occurred in each of the predetermined number of pairs G1 to G4" means whether or not the first short circuit occurred at the counter electrodes 11 and 12 of each pair G1 to G4. The predetermined number of pairs is the number required for the prediction unit 40 to determine the correlation (for example, the correlation line). The larger the predetermined number, the more accurate the correlation can be.

[0149] Furthermore, if the prediction unit 40 determines that a short circuit has occurred in each of the predetermined number of pairs G1 to G4 of the opposing electrodes 11 and 12 based on the determination results of each determination unit 32, it associates the interval s1 of the pair with the detection time of the short circuit that occurred in each of the predetermined number of pairs G1 to G4. In this way, the prediction unit 40 determines the correspondence between the interval s1 and the detection time in each of the predetermined number of pairs G1 to G4. Then, based on the determined correspondence, the prediction unit 40 creates a correlation between the interval s1 and the detection time (for example, a correlation diagram and a correlation line L1) (see Figure 15). The correlation diagram between the interval s1 and the detection time is, for example, a diagram in which points (for example, points Q1 to Q4) are plotted on a planar coordinate system with the foreign object size (interval s1) on the horizontal axis and the detection time on the vertical axis, at coordinate positions specified by the corresponding interval s1 and detection time. The foreign object size on the horizontal axis is the size of the detected metal foreign object F1. As described in "(1-4) Estimation of the Optimal Detectable Size of Metal Foreign Matter" of Embodiment 1, the size of the foreign matter F1 is determined according to the spacing s1 between the opposing electrodes 11 and 12; therefore, the foreign matter size on the horizontal axis corresponds to the spacing s1. Note that the horizontal axis may also represent the spacing s1.

[0150] The prediction unit 40 then predicts the detection time N1 of a metal foreign object F1 of a predetermined size M1, based on the created correlation (e.g., correlation diagram). More specifically, the prediction unit 40 finds a correlation line L1 in the correlation diagram and uses the found correlation line L1 to determine the detection time N1 when the interval s1 is of the predetermined size M1 (see Figure 15). In the example in Figure 15, the correlation line L1 is a line drawn so as to best fit the three points Q2 to Q4 where the detection time is greater than 0.

[0151] The display unit 34 is a display device capable of displaying various information, such as a liquid crystal display device, similar to the display unit 34 in Embodiment 1. The display unit 34 displays the prediction result of the prediction unit 40 (the predicted value of the detection time for a metal foreign object of a predetermined size).

[0152] (4-2) The operation (prediction method) of the prediction device 100 will be explained with reference to the operation diagram 16.

[0153] The detection device 1 is installed in a predetermined location (for example, on the floor around a cutting device used in the cutting process of the lithium-ion battery manufacturing process). The time measurement unit 33 starts timing the detection time (ST31). Then, the drive mechanism 7 starts moving the roller 6 in conjunction with the start of timing by the time measurement unit 33 (ST32). More specifically, the drive mechanism 7 starts moving the roller 6 from one end 14a, 14b of the detection range 14 to the other. Also, each measurement unit 31 starts measuring the resistance value between the corresponding pairs of counter electrodes 11, 12 G1 to G5 in conjunction with the start of the movement of the roller 6 (ST33). When the roller 6 moves over a metal foreign object F1 placed between one pair of counter electrodes 11, 12 from among the multiple pairs G1 to G5, the short-circuit state between the pair of counter electrodes 11, 12 caused by the metal foreign object F1 is improved, and the resistance value between the pair of counter electrodes 11, 12 drops sharply to below the threshold.

[0154] Each determination unit 32 determines whether or not a short circuit has occurred at the corresponding counter electrodes 11 and 12 of G1 to G5 based on the measurement result of the corresponding measurement unit 31 (ST34). More specifically, each determination unit 32 determines that a short circuit has occurred if the measurement result (electrical resistance value) of the corresponding measurement unit 31 falls below a threshold, and determines that a short circuit has not occurred if the measurement result of the corresponding measurement unit 31 does not fall below a threshold. If none of the determination units 32 determine that a short circuit has occurred at the corresponding counter electrodes 11 and 12 of G1 to G5 (ST34: No), the process proceeds to step ST35.

[0155] In step ST35, if the roller 6 has not moved to the other end of the detection range 14 and the movement of the roller 6 has not finished (ST35: No), the process returns to step ST34. On the other hand, if the roller 6 has moved to the other end of the detection range 14 and the movement of the roller 6 has finished (ST35: Yes), the process waits for a certain amount of time to elapse from the end of the movement of the roller 6 in step ST35 (ST36) and then returns to step ST32.

[0156] On the other hand, if, as a result of the determination in step ST34, any determination unit 32 determines that a short circuit has occurred between the corresponding opposing electrodes 11 and 12 of G1 to G5 (ST34: Yes), the time measurement unit 33 measures the time (detection time) from the start of timing in step ST31 to the determination point in step ST34 (ST37).

[0157] The prediction unit 40 then determines whether a short circuit has occurred in two or more predetermined pairs of G1 to G4 counter electrodes 11, 12 where the interval s1 is smaller than a predetermined size (ST38). If the result of this determination is that no short circuit has occurred in the predetermined number of pairs of G1 to G4 counter electrodes 11, 12 (ST38: No), the process proceeds to step ST35. On the other hand, if the result of the determination in step ST38 is that a short circuit has occurred in the predetermined number of pairs of G1 to G4 counter electrodes 11, 12 (ST38: Yes), the prediction unit 40 associates the detection time measured in step ST37 with the interval s1 of the pair in which a short circuit was determined to have occurred in step ST34 for each of the predetermined number of pairs of G1 to G4. In this way, the prediction unit 40 determines the correspondence between the interval s1 of the pair and the detection time of the short circuit that occurred in the pair for each of the predetermined number of pairs of G1 to G4 (ST39).

[0158] Then, the prediction unit 40 determines the correlation between the interval s1 and the detection time (for example, the correlation diagram and correlation line L1 in Figure 15) based on the above correspondence (ST40). Then, the prediction unit 40 predicts the detection time N1 of a short circuit caused by a metal foreign object F1 of a predetermined size M1 based on the determined correlation (see Figure 15, ST41). Then, the display unit 34 displays the prediction result of the prediction unit 40 (predicted value of detection time) (ST42). Then, the process ends.

[0159] (4-3) Examples of applications of the prediction device The prediction device 100 can predict the detection time of a metal foreign object F1 of a predetermined size falling through the atmosphere. For example, in a lithium-ion manufacturing process, by predicting the detection time of a metal foreign object F1 of a predetermined size (for example, about 100 μm) that would otherwise require the product to be discarded, the manufacturing line can be stopped before the predicted time has elapsed, and various devices used in the manufacturing process can be maintained, thereby avoiding the discarding of the product when the above-mentioned metal foreign object F1 of the predetermined size is detected.

[0160] (4-4) The prediction device 100 according to the effect embodiment 4 is equipped with the detection device 1 of embodiment 1. In the prediction device 100, the electrode sheet 5 has a plurality of pairs of counter electrodes 11, 12 G1 to G5. The spacing s1 between each of the plurality of pairs of counter electrodes 11, 12 G1 to G5 is of a different size. The insulating sheet 13 of the electrode sheet 5 supports the plurality of pairs of counter electrodes 11, 12 G1 to G5. The prediction device 100 further comprises a time measurement unit 33 and a prediction unit 40. The time measurement unit 33 measures the detection time of a short circuit caused by a metal foreign object F1 smaller than a predetermined size, which has been determined to have occurred by the determination unit 32. The prediction unit 40 predicts the detection time of a short circuit caused by a metal foreign object F1 of a predetermined size falling through the air. The detection time is the time from a predetermined point in time to the point in time when the determination unit 32 determines that a short circuit has occurred. The prediction unit 40 determines the correlation between the spacing s1 and detection time for two or more predetermined pairs of counter electrodes 11, 12 of G1 to G4, where the spacing s1 is smaller than a predetermined size, and predicts the detection time for a short circuit caused by a metal foreign object F1 of a predetermined size based on the determined correlation. With this configuration, it is possible to predict the detection time for a short circuit caused by a metal foreign object F1 of a predetermined size (i.e., the detection time for a metal foreign object F1 of a predetermined size).

[0161] Furthermore, the prediction device 100 according to Embodiment 4 includes a plurality of measurement units 31 and a plurality of determination units 32. The plurality of measurement units 31 correspond to a plurality of pairs of counter electrodes 11, 12 G1 to G5 and measure the electrical values ​​between the corresponding pairs of counter electrodes 11, 12. The plurality of determination units 32 correspond to the plurality of measurement units 31 and determine whether or not a short circuit has occurred between the corresponding pairs of counter electrodes 11, 12 based on the determination result of the corresponding determination unit 32. With this configuration, the occurrence of a short circuit can be easily distinguished by the plurality of electrode sheets 5.

[0162] Furthermore, in the prediction device 100 according to Embodiment 4, the installation area (detection range 14) of each pair of opposing electrodes 11, 12 of the multiple pairs G1 to G5 is larger the greater the distance s1 between the pairs of opposing electrodes 11, 12. With this configuration, larger metal foreign objects F1 (i.e., metal foreign objects F1 that occur infrequently) can be detected more reliably. In this configuration, it is assumed that the larger the size of the metal foreign object F1, the less frequently it occurs.

[0163] (4-5) Functions similar to those of the prediction device 100 according to Embodiment 4 of the other embodiments may be embodied in a prediction method, a computer program (program), or a non-temporary recording medium on which a computer program is recorded.

[0164] One embodiment of the prediction method includes the detection method described above. In the detection method, the electrode sheet 5 has a plurality of pairs G1 to G5, including the pair of counter electrodes 11 and 12 described above. The spacing s1 between each of the plurality of pairs G1 to G5 of counter electrodes 11 and 12 is different from that of the others. The insulating sheet 13 of the electrode sheet 5 supports the plurality of pairs G1 to G5 of counter electrodes 11 and 12. The prediction method further includes a time measurement step ST37 and a prediction step ST41. In the time measurement step ST37, the detection time of a short circuit caused by a metal foreign object F1 smaller than a predetermined size, which has been determined to have occurred by the determination step ST34, is measured. In the prediction step ST41, the detection time of a short circuit caused by a metal foreign object F1 of a predetermined size falling through the air is predicted. The detection time is the time from a predetermined point in time to the point in time when the determination step ST34 determines that a short circuit has occurred. In the prediction step ST41, the correlation between the spacing s1 and detection time is determined for two or more predetermined pairs of counter electrodes 11, 12 of G1 to G5 where the spacing s1 is smaller than a predetermined size. Based on the determined correlation, the detection time for a short circuit caused by a metal foreign object F1 of a predetermined size is predicted.

[0165] A program according to one embodiment causes one or more processors to execute the above-described prediction method.

[0166] A non-temporary recording medium according to one embodiment records a program that causes one or more processors to execute the above prediction method.

[0167] (4-6) Modifications of Embodiment 4 are listed below. The modifications described below can be combined and applied as appropriate.

[0168] (4-6-1) Modification 1 In Embodiment 4, an example is given where the larger the interval s1, the larger the installation area (e.g., detection range 14) of the opposing electrodes 11 and 12 of each pair G1 to G5 (see Figure 14). If the installation area of ​​the opposing electrodes 11 and 12 of a pair (e.g., G4) is made relatively larger than the reference area (e.g., the installation area of ​​the opposing electrodes 11 and 12 of pair G1), the number of short circuits detected (number of occurrences) at the opposing electrodes 11 and 12 of pair G4 when the installation area is made relatively larger than the reference area will be greater than the number of short circuits detected at the opposing electrodes 11 and 12 of pair G4 when the installation area is not made relatively larger than the reference area (i.e., the reference area), by the amount of the increased installation area. For example, if the installation area of ​​the counter electrodes 11 and 12 for G4 is increased to N times the standard area, the number of short circuits detected at the counter electrodes 11 and 12 for G4 when the installation area is increased to N times the standard area will be N times the number of short circuits detected at the counter electrodes 11 and 12 for G4 when the installation area is the standard area. For this reason, it is desirable to correct the measured value of the number of short circuits detected at the counter electrodes 11 and 12 for G4 when the installation area is increased to N times the standard area by multiplying it by 1 / N. For this reason, when the counting unit 37 measures the number of short circuits detected at a pair of counter electrodes 11 and 12 with an installation area increased to N times the standard area, it is desirable to correct the measured value by multiplying it by 1 / N. Alternatively, instead of correcting the measured value by multiplying it by 1 / N, if a threshold is set for the number of detections, that threshold may be corrected by N times.

[0169] Increasing the installation area of ​​the counter electrodes 11 and 12 for pairs G1 to G5 means that the counter electrodes 11 and 12 for pairs G1 to G5 may be configured so that the detection range 14 of the counter electrodes 11 and 12 for pairs G1 to G5 is increased, or the number of the same pairs G1 to G5 may be increased. In the example in Figure 17, when there are two types of counter electrodes 11 and 12 for pairs G2 and G4 with different spacing s1 (s12, s14), the installation area of ​​the counter electrodes 11 and 12 for pair G4 with a relatively large spacing s14 is increased by making the number of counter electrodes 11 and 12 for pair G4 with a relatively large spacing s14 (3 electrodes) greater than the number of counter electrodes 11 and 12 for pair G2 with a relatively small spacing s12 (1 electrode).

[0170] (4-6-2) Modification 2 A metal foreign object of a size corresponding to a relatively large interval s1 (e.g., interval s14) (large foreign object) is detected by the opposing electrodes 11, 12 of pair G2 having a relatively small interval s1 (e.g., interval s12) and is detected as a metal foreign object of a size corresponding to a relatively small interval s1 (small foreign object). Furthermore, the larger the size of the metal foreign object (i.e., the larger the foreign object), the lower the frequency of occurrence of metal foreign objects. Considering these factors, in Embodiment 4, if the installation area (e.g., detection range 14) of each of the multiple pairs of opposing electrodes 11, 12 of G1 to G5 with different intervals s11 to s15 is the same size, then large foreign objects (metal foreign objects with a low occurrence frequency) are detected as small foreign objects with a higher probability. For this reason, it may become impossible to accurately measure the detection time of large foreign objects.

[0171] Therefore, the larger the interval s1, the larger the set area of ​​the counter electrodes 11 and 12 for each pair of G1 to G5. This makes it easier to detect large foreign objects as large foreign objects, allowing for more accurate measurement of the detection time of large foreign objects. Furthermore, regarding small foreign objects, although the installation range of the pairs of counter electrodes 11 and 12 with the corresponding interval s1 becomes relatively small, the frequency of small foreign objects is high, and small foreign objects are not detected as large foreign objects, allowing for accurate measurement of the detection time of small foreign objects.

[0172] Furthermore, increasing the installation area of ​​the counter electrodes 11 and 12 for each of the G1 to G5 means that the counter electrodes 11 and 12 for each of the G1 to G5 may be configured to increase the detection range 14 of the counter electrodes 11 and 12 for each of the G1 to G5, or the number of the same G1 to G5 electrodes may be increased.

[0173] (5) Embodiment 5 A prediction device 100 according to Embodiment 5 will be described with reference to Figures 18 and 19.

[0174] (5-1) The prediction device 100 according to the configuration embodiment 5 is configured in the prediction device 100 according to embodiment 4 to predict the detection time of a metal foreign object F1 of a predetermined size falling in the atmosphere using a pair of opposing electrodes (a pair of connected opposing electrodes 18, 19). In the following description, the same reference numerals are used for components that are the same as those in the prediction device 100 of embodiment 4 and their descriptions are omitted, while the description may focus on components that are different from the prediction device 100.

[0175] As shown in Figure 18, the prediction device 100 according to Embodiment 5 comprises an electrode sheet section 102 and a detection circuit section 103.

[0176] (5-1-1) Electrode Sheet Section The electrode sheet section 102 captures multiple metallic foreign objects F1 of various sizes that fall through the air. As shown in Figure 18, the electrode sheet section 102 of Embodiment 5 is equipped with an electrode sheet 15, a roller 6, and a drive mechanism 7, similar to the electrode sheet section 2 of Embodiment 4.

[0177] Since the roller 6 and drive mechanism 7 of Embodiment 5 are configured in the same way as the roller 6 and drive mechanism 7 of Embodiment 4, a detailed explanation will be omitted.

[0178] The electrode sheet 15 of Embodiment 5 is configured similarly to the electrode sheet 5 of Embodiment 4, except that it has a pair of connected counter electrodes 18 and 19 instead of a plurality of pairs of counter electrodes 11 and 12 G1 to G5.

[0179] The pair of connected opposing electrodes 18 and 19 are configured in the multiple pairs of opposing electrodes 11 and 12 of G1 to G5 in Embodiment 4 by connecting the first opposing electrodes 11 to each other (more specifically, the first connecting portions 11b to each other) and the second opposing electrodes 12 to each other (more specifically, the second connecting portions 12b to each other). The multiple pairs of opposing electrodes 11 and 12 of G1 to G5 are arranged in a line along the direction of movement of the roller 6 (first direction T1).

[0180] More specifically, the pair of connected opposing electrodes 18 and 19 comprises a first connected opposing electrode 18 and a second connected opposing electrode 19.

[0181] The first connecting opposing electrode 18 has multiple pairs of first wiring electrode portions 11a each of G1 to G5, and a first connecting portion 18b. The multiple pairs of first wiring electrode portions 11a each of G1 to G5 are arranged in a line with spacing along the movement direction T1 of the roller 6. The first connecting portion 18b is, for example, strip-shaped and is connected to one end of the multiple pairs of first wiring electrode portions 11a each of G1 to G5. That is, the multiple pairs of first wiring electrode portions 11a each of G1 to G5 protrude from one side of the first connecting portion 18b in the width direction of the first connecting portion 18b.

[0182] The second connecting opposing electrode 19 has multiple pairs of second wiring electrode portions 12a each of G1 to G5, and a second connecting portion 19b. The multiple pairs of second wiring electrode portions 12a each of G1 to G5 are arranged in a line with spacing along the movement direction T1 of the roller 6. The second connecting portion 19b is, for example, strip-shaped and is connected to one end of the multiple pairs of second wiring electrode portions 12a each of G1 to G5. That is, the multiple pairs of second wiring electrode portions 12a each of G1 to G5 protrude from one side of the second connecting portion 19b in the width direction of the second connecting portion 19b.

[0183] The multiple second wiring electrode portions 12a of each pair G1 to G5 are arranged alternately with the multiple first wiring electrode portions 11a of the same pair, with a spacing s1 specific to that pair. That is, the multiple first wiring electrode portions 11a and the multiple second wiring electrode portions 12a of pair G1 are arranged alternately with a spacing s11 specific to pair G1. The multiple first wiring electrode portions 11a and the multiple second wiring electrode portions 12a of pair G2 are arranged alternately with a spacing s12 specific to pair G2. The multiple first wiring electrode portions 11a and the multiple second wiring electrode portions 12a of pair G3 are arranged alternately with a spacing s13 specific to pair G3. The multiple first wiring electrode portions 11a and the multiple second wiring electrode portions 12a of pair G4 are arranged alternately with a spacing s14 specific to pair G4. The multiple first wiring electrode portions 11a and multiple second wiring electrode portions 12a relative to G5 are arranged alternately with a specific interval s15 between them relative to G5.

[0184] The installation areas of the opposing electrodes 11 and 12 for each pair G1 to G5 are, for example, different in size. More specifically, the installation areas of each pair G1 to G5 are larger in the order of G1, G2, G3, G4, and G5. The installation area of ​​the opposing electrodes 11 and 12 for each pair G1 to G5 is the same as the detection range 14 of the opposing electrodes 11 and 12 for each pair G1 to G5. The installation areas of each pair G1 to G5 may be the same size.

[0185] The detection range 16 of the electrode sheet 15 is the area that exactly surrounds the pair of connected opposing electrodes 18 and 19.

[0186] (5-1-2) Detection Circuit Unit As shown in Figure 18, the detection circuit unit 103 predicts the detection time of a larger predetermined size metal foreign object F1 based on the correlation between the size and detection time of multiple metal foreign objects F1 of various sizes captured by the electrode sheet unit 102. As shown in Figure 18, the detection circuit unit 103 includes a measurement unit 31, a determination unit 32, a time measurement unit 33, a display unit 34, a drive control unit 35, a position measurement unit 36, and a counting unit 37.

[0187] The measuring unit 31 measures the electrical value (e.g., resistance value) between the pair of connected opposing electrodes 18 and 19 of the electrode sheet 15.

[0188] The position measuring unit 36 ​​measures the position of the roller 6 on the electrode sheet 15. The position of the roller 6 is, for example, the position between the first end 16a and the second end 16b within the detection range 16 of the electrode sheet 15. More specifically, the position measuring unit 36 ​​measures the time from the start of movement of the roller 6 and measures the position of the roller 6 based on the length of this measured time. For example, when moving the roller 6 from one end 16a, 16b of the detection range 16 to the other end, the time from the start of movement of the roller 6 from the end is measured. Since the movement speed of the roller 6 is constant, it is possible to measure the position of the roller 6 by the measured time.

[0189] The determination unit 32 determines whether or not a short circuit has occurred between the pair of connected opposing electrodes 18 and 19 of the electrode sheet 15, based on the measurement results of the measurement unit 31. More specifically, the determination unit 32 determines whether or not a short circuit has occurred depending on whether or not the measurement result (e.g., resistance value) of the measurement unit 31 falls below a threshold. For example, the determination unit 32 determines that a short circuit has occurred if the measurement result (e.g., resistance value) of the measurement unit 31 falls below a threshold, and determines that a short circuit has not occurred if the measurement result (e.g., resistance value) of the measurement unit 31 is not below a threshold.

[0190] More specifically, the determination unit 32 identifies the location of the short circuit at the time of determination based on the measurement result of the position measurement unit 36 ​​at the time of determination (the position of the roller 6, i.e., the location of the short circuit). The determination unit 32 then validates the determination result if the identified location of the short circuit is not the same as a previously identified location (i.e., it is a short circuit at a new location). In other words, the determination unit 32 ultimately determines that a short circuit occurred at the identified location, in association with the identified location of the short circuit. On the other hand, the determination unit 32 invalidates the determination result if the identified location of the short circuit is the same as a previously identified location (i.e., it is not a short circuit at a new location). In other words, the determination unit 32 ultimately determines that no short circuit occurred at the identified location. Hereafter, this process of determining whether or not the short circuit location is the first location will be referred to as the short circuit location determination process.

[0191] In the fifth embodiment, if it can be assumed that all short circuits occur at different roller positions, the short-circuit position determination process of the determination unit 32 may be omitted.

[0192] The time measurement unit 33, similar to the time measurement unit 33 in Embodiment 4, measures the detection time of a short circuit (a short circuit caused by a metal foreign object F1 smaller than a predetermined size) that has been determined to have occurred by the determination unit 32. More specifically, the time measurement unit 33 measures the time (detection time) from a predetermined point in time (for example, when the prediction device 100 is started or when short circuit detection begins) to the point in time when the determination unit 32 determines that a short circuit has occurred.

[0193] Based on the measurement results of the position measurement unit 36, the counting unit 37 identifies the pair in which a short circuit occurred, as determined by the determination unit 32, from among the multiple pairs G1 to G5. Then, based on the identification result of the counting unit 37 and the determination result of the determination unit 32, the counting unit 37 counts the number of times a short circuit occurred in the electrode sheet 15 (i.e., a short circuit occurred in the pair of connected opposing electrodes 18 and 19) for each of the multiple pairs G1 to G5.

[0194] The prediction unit 40 predicts the detection time for a short circuit caused by a metal foreign object F1 of a predetermined size (i.e., the detection time for a metal foreign object F1 of a predetermined size).

[0195] More specifically, the prediction unit 40, similar to the prediction unit 40 of Embodiment 4, determines the correspondence between the interval s1 (i.e., foreign object size) and the detection time in each of two or more predetermined pairs (e.g., G1 to G4) from a plurality of pairs G1 to G5 where the interval s1 is smaller than the predetermined size. The prediction unit 40 also determines the correlation between the interval s1 and the detection time (e.g., the correlation diagram and correlation line L1 described later) based on the determined correspondence. The prediction unit 40 also predicts the detection time of a short circuit caused by a metal foreign object F1 of the predetermined size based on the determined correlation.

[0196] More specifically, the prediction unit 40 identifies the pair in which a short circuit has occurred, as determined by the determination unit 32, from among multiple pairs G1 to G5, based on the measurement results of the position measurement unit 36. The prediction unit 40 also determines, based on the identification results of the prediction unit 40 and the counting results of the counting unit 37, whether or not one or more short circuits have occurred in each of the predetermined number of pairs G1 to G4. If the prediction unit 40 determines that one or more short circuits have occurred in each of the predetermined number of pairs G1 to G4, it calculates the average value (average detection time) of the detection times of one or more short circuits measured in each of the predetermined number of pairs G1 to G4, based on the measurement results of the time measurement unit 33. In the case of a pair in which only the detection time of one short circuit has been measured, the detection time of that one short circuit becomes the average short circuit time.

[0197] Furthermore, since pairs with smaller intervals s1 have a higher frequency of short circuits, in a situation where short circuits occur in all of the predetermined number of pairs G1 to G4, more short circuits are detected in the pairs with smaller intervals s1 among the predetermined number of pairs G1 to G4. In this way, for pairs in which multiple short circuits are detected, it is necessary to calculate the average of the detection times of multiple short circuits (average detection time) in order to create the correlation described later.

[0198] The prediction unit 40 then calculates the average short-circuit detection time for each of the predetermined number of pairs G1 to G4, and associates the short-circuit detection time (average detection time) with the pair interval s1 (i.e., foreign object size) for each of the predetermined number of pairs G1 to G4. This allows the prediction unit 40 to determine the correspondence between the interval s1 (foreign object size) and the detection time (average detection time) for each of the predetermined number of pairs G1 to G4. Then, similar to the prediction unit 40 in Embodiment 4, the prediction unit 40 creates a correlation between the interval s1 and the detection time (for example, a correlation diagram and a correlation line L1) based on the determined correspondence (see Figure 15). Finally, similar to the prediction unit 40 in Embodiment 4, the prediction unit 40 predicts the detection time N1 of a metal foreign object F1 of a predetermined size M1 based on the created correlation.

[0199] The display unit 34 is a display device capable of displaying various information, such as a liquid crystal display device, similar to the display unit 34 in Embodiment 1. The display unit 34 displays the prediction result of the prediction unit 40 (predicted value of detection time for a predetermined size M1).

[0200] (5-2) Referring to the operation diagram 19, the operation of the prediction device 100 according to Embodiment 5 (a prediction method for predicting the detection time of a metal foreign object F1 of a predetermined size) will be described.

[0201] The detection device 1 is installed in a predetermined location (for example, on the floor around a cutting device used in the cutting process of the manufacturing process of lithium-ion batteries). The time measurement unit 33 starts timing the detection time (ST41). The drive mechanism 7 then starts moving the roller 6 in conjunction with the start of timing by the time measurement unit 33 (ST42). More specifically, the drive mechanism 7 starts moving the roller 6 from one end 16a, 16b of the detection range 16 of the electrode sheet 15 to the other. The position measurement unit 36 ​​also starts measuring the position of the roller 6 in conjunction with the start of the roller 6's movement (ST43). The measurement unit 31 also starts measuring the resistance value between the first wiring electrode portion 11a and the second wiring electrode portion 12a of each pair G1 to G5 of the electrode sheet 15 in conjunction with the start of the roller 6's movement (ST44). As the roller 6 moves over the metal foreign object F1 positioned between the first wiring electrode portion 11a and the second wiring electrode portion 12a, the short-circuit state between the first wiring electrode portion 11a and the second wiring electrode portion 12a caused by the metal foreign object F1 is improved, and the resistance value between the pair of connected opposing electrodes 18 and 19 drops sharply to below the threshold.

[0202] The determination unit 32 determines whether or not a short circuit has occurred in the electrode sheet 15 based on the measurement results of the measurement unit 31 and the measurement results of the position measurement unit 36 ​​(ST45). More specifically, the determination unit 32 determines that no short circuit has occurred if the measurement result of the measurement unit 31 is not below a threshold. Also, the determination unit 32 determines that a short circuit has occurred if the measurement result of the measurement unit 31 falls below a threshold. More specifically, the determination unit 32 identifies the location of the short circuit based on the measurement result of the position measurement unit 36 ​​at the time of determination (i.e., the measurement result of step ST43). If the identified location of the short circuit is the same as a short circuit already identified, the determination result is invalidated, and the determination unit 32 ultimately determines that no short circuit has occurred. Also, if the identified location of the short circuit is not the same as a short circuit already identified, the determination result is valid, and the determination unit 32 ultimately determines that a short circuit has occurred. If the determination unit 32 determines that no short circuit has occurred (ST45: No), the process proceeds to step ST46.

[0203] In step ST46, if the roller 6 has not moved to the other end of the detection range 16 of the electrode sheet 15 and the movement of the roller 6 has not finished (ST46: No), the process returns to step ST45. On the other hand, if the roller 6 has moved to the other end of the detection range 16 and the movement of the roller 6 has finished (ST46: Yes), the position measuring unit 36 ​​finishes measuring the position of the roller 6 (ST47). Then, after waiting for a certain amount of time to elapse since the end of the movement of the roller 6 in step ST46 (ST48), the process returns to step ST42.

[0204] On the other hand, if the determination unit 32 determines, as a result of the determination in step ST45, that a short circuit has finally occurred (ST45: Yes), the time measurement unit 33 measures the time (detection time) from the start of timing in step ST41 to the determination in step ST45, in correspondence with the measurement result of the position measurement unit 36 ​​at the time of determination by the determination unit 32 (i.e., the position of the short circuit) (ST49).

[0205] Then, the counting unit 37 identifies the pair in which a short circuit occurred, as determined by the determination unit 32, from among multiple pairs G1 to G5, based on the measurement results of the position measuring unit 36. Then, the counting unit 37 counts the number of times a short circuit occurred in the electrode sheet 15 for each pair G1 to G5, based on the identification results of the counting unit 37 and the determination results of the determination unit 32. Then, the prediction unit 40 determines, based on the counting results of the counting unit 37, whether a short circuit has occurred in each of two or more predetermined pairs G1 to G4 where the interval s1 is smaller than a predetermined size (ST50). If, as a result of this determination, no short circuit has occurred in each of the predetermined number of pairs G1 to G4 (ST50: No), the process proceeds to step ST46. On the other hand, if the determination in step ST50 indicates that a short circuit occurs in each of the predetermined number of pairs of G1 to G4 (ST50: Yes), the prediction unit 40 calculates the average value of the short circuit detection time (average detection time) for each of the predetermined number of pairs of G1 to G4 (ST51).

[0206] Then, the prediction unit 40 associates the short-circuit detection time (average detection time) obtained in step ST51 with the interval s1 of the pair in which the short-circuit occurred, which was determined to have occurred in step ST45, for each of the predetermined number of pairs G1 to G4. As a result, the prediction unit 40 determines the correspondence between the interval s1 (foreign object size) and the detection time for each of the predetermined number of pairs G1 to G4 (ST52).

[0207] The prediction unit 40 then determines the correlation between the interval s1 and the detection time (for example, the correlation diagram and correlation line L1 in Figure 15) based on the correspondence between each of the predetermined number of pairs G1 to G4 (ST53). The prediction unit 40 then predicts the detection time N1 of a short circuit caused by a metal foreign object F1 of a predetermined size M1 based on the determined correlation (ST54). The display unit 34 then displays the detection time N1 predicted by the prediction unit 40 (ST55). The process then ends.

[0208] (5-3) Application Fields of the Prediction Device In the prediction device 100 according to Embodiment 5, similar to the prediction device 100 according to Embodiment 4, for example, in the lithium-ion manufacturing process, by predicting the detection time of a metal foreign object F1 of a predetermined size (for example, about 100 μm) that requires the product to be discarded, the manufacturing line can be stopped before the predicted time has elapsed, and various devices used in the manufacturing process can be maintained, thereby reducing the amount of product that needs to be discarded when the above-mentioned metal foreign object F1 of the predetermined size is detected.

[0209] (5-4) The prediction device 100 according to the 5th embodiment of the effect comprises a pair of connected opposing electrodes 18 and 19, a roller 6, and a drive mechanism 7. The pair of connected opposing electrodes 18 and 19 connect the first opposing electrodes 11 to each other and the second opposing electrodes 12 to each other in a plurality of pairs of opposing electrodes 11 and 12 G1 to G5. The roller 6 is insulating. The roller 6 moves within the detection range 16 of the pair of connected opposing electrodes 18 and 19. The drive mechanism 7 moves the roller 6 within the detection range 16 of the pair of connected opposing electrodes 18 and 19 at regular intervals. The prediction device 100 further comprises a position measuring unit 36 ​​that measures the position of the roller 6 within the detection range 16 of the pair of connected opposing electrodes 18 and 19 when the determination unit 32 determines that a short circuit has occurred. Based on the measurement results of the position measuring unit 36, the prediction unit 40 identifies the pair in which a short circuit has occurred from a predetermined number of pairs G1 to G4. The prediction unit 40 calculates the average time of short-circuit detection time measured by the time measurement unit 33 for each of a predetermined number of pairs G1 to G4, and determines the correlation by associating the interval s1 of the pairs with the average time.

[0210] With this configuration, by identifying the location of the short circuit at the position of the roller 6, multiple short circuits can be easily detected using a pair of connected opposing electrodes 18 and 19. This reduces the number of measurement units 31 and determination units 32 to the equivalent of the pair of connected opposing electrodes 18 and 19 (i.e., one unit).

[0211] Furthermore, in the prediction device 100 according to Embodiment 5, the pair of connected opposing electrodes 18 and 19 have multiple pairs of opposing electrodes 11 and 12 G1 to G5 arranged in the direction T1 in which the roller 6 moves. With this configuration, the pair of connected opposing electrodes 18 and 19 can be configured so that the location of a short circuit that has occurred can be easily distinguished by the position of the roller 6.

[0212] Furthermore, in the prediction device 100 according to Embodiment 5, the drive mechanism 7 comprises a drive unit 71 and a guide unit 72. The drive unit 71 moves the roller 6. The guide unit 72 moves the roller 6 in one direction. With this configuration, the roller 6 can be moved easily.

[0213] Furthermore, in the prediction device 100 according to Embodiment 5, the first main surface 13a (main surface) of the insulating sheet 13 has a plurality of first recesses 131 and a plurality of second recesses 132. The plurality of first recesses 131 correspond to a plurality of pairs of opposing electrodes 11, 12 G1 to G5, and the first opposing electrode 11 of the corresponding pair of opposing electrodes 11, 12 is fitted into each of the first recesses 131. The plurality of second recesses 132 correspond to a plurality of pairs of opposing electrodes 11, 12 G1 to G5, and the second opposing electrode 12 of the corresponding pair of opposing electrodes 11, 12 is fitted into each of the second recesses 132. The exposed surface 11u (first exposed surface) of the first opposing electrode 11 is positioned at the same height as the first main surface 13a of the insulating sheet 13 or at a lower height than the first main surface 13a. The exposed surface 12u (second exposed surface) of the second opposing electrode 12 is positioned at the same height as the first main surface 13a of the insulating sheet 13, or at a lower height than the first main surface 13a.

[0214] With this configuration, the current flowing through the short circuit caused by the metal foreign object F1 can be improved only while the roller 6 is on top of the metal foreign object F1. This makes it easy to distinguish the location of the short circuit that has occurred based on the position of the roller 6.

[0215] (5-5) Modifications of Embodiment 4 are listed below. The modifications described below can be combined and applied as appropriate.

[0216] (5-5-1) Modification 1 In Embodiment 5, as in Modification 1 of Embodiment 4, the installation area of ​​the opposing electrodes 11 and 12 of each pair G1 to G5 may be made relatively larger with respect to the reference area (for example, the set area of ​​the pair G1 with the smallest set area). In this case, it is desirable to correct the number of detected short circuits occurring in the pair whose installation area is made relatively larger with respect to the reference area so that it is reduced by the amount by which the installation area is made relatively larger with respect to the reference area. Alternatively, instead of correcting the measured value to be reduced, if a threshold is set for the number of detections, it may be corrected to make that threshold larger.

[0217] (5-5-2) Modification 2 In Embodiment 5, as in Modification 2 of Embodiment 4, it is desirable to increase the set area for G1 to G5 as the interval s1 increases.

[0218] (5-5-3) Modification 3 In Embodiment 5, as in Modification 2 of Embodiment 3, the short-circuit position determination process of the determination unit 32 may be performed by an external processing unit.

[0219] Furthermore, in Embodiment 5, the identification process of the counting unit 37 and the prediction unit 40 (the process of identifying the pair in which a short circuit has occurred, as determined by the determination unit 32, from among the multiple pairs G1 to G5) may also be performed by an external processing unit. In this case, similar to Modification 2 of Embodiment 3, the detection circuit unit 103 further includes a communication unit that performs data communication with the external processing unit. The detection circuit unit 103 transmits the measurement value of the position measuring unit 36 ​​at the time the determination unit 32 determined that a short circuit had occurred to the external processing unit via the communication unit. The external processing unit stores the received measurement value in a storage unit. Based on the received measurement value, the external processing unit identifies the location of the short circuit determined by the determination unit 32, and based on the identified short circuit location, it identifies which pair of the multiple pairs G1 to G5 corresponds to the identified short circuit location. The external processing unit then transmits the identification result to the detection circuit unit 103 via the communication unit. The detection circuit unit 103 then executes processing based on the identification result from the external processing unit, with the counting unit 37 and the prediction unit 40 performing the processing.

[0220] (5-5-4) Other modified embodiments 1 to 5 and their modified embodiments may be implemented in combination.

[0221] (6) The following aspects are disclosed in this disclosure:

[0222] The detection device (1) of the first embodiment comprises an electrode sheet (5), a measuring unit (31), and a determination unit (32). The electrode sheet (5) has a pair of counter electrodes (11, 12) and an insulating sheet (13). The pair of counter electrodes (11, 12) includes a first counter electrode (11) and a second counter electrode (12). The insulating sheet (13) supports the pair of counter electrodes (11, 12). The first counter electrode (11) has a plurality of first wiring electrode portions (11a), and the second counter electrode (12) has a plurality of second wiring electrode portions (12a). The plurality of second wiring electrode portions (12a) are arranged alternately with the plurality of first wiring electrode portions (11a) at intervals (s1). The measuring unit (31) measures the electrical value between the pair of counter electrodes (11, 12). The determination unit (32) determines, based on the measurement results from the measurement unit (31), whether or not a short circuit has occurred between the pair of opposing electrodes (11, 12) due to a metallic foreign object (F1) falling through the air.

[0223] This configuration allows for the detection of metallic foreign objects (F1) falling through the atmosphere. More specifically, it allows for the detection of metallic foreign objects (F1) of a size corresponding to the distance (s1) between the first wiring electrode section (11a) and the second wiring electrode section (12a).

[0224] In the detection device (1) of the second embodiment, in the first embodiment, the electrode sheet (5) has a plurality of pairs (G1 to G5) of counter electrodes (11, 12), each including a pair of counter electrodes (11, 12). The spacing (s1) between each of the plurality of pairs (G1 to G5) of counter electrodes (11, 12) is the same. The detection device (1) includes a plurality of measuring units (31), a plurality of determination units (32), and a counting unit (37). The plurality of measuring units (31) include the measuring unit (31). The plurality of measuring units (31) correspond to the plurality of pairs (G1 to G5) of counter electrodes (11, 12) and measure the electrical value between the corresponding pairs of counter electrodes (11, 12). The plurality of determination units (32) include the determination unit (32). Multiple determination units (32) correspond to multiple measurement units (31) and determine whether or not a short circuit has occurred between the corresponding pairs of opposing electrodes (11, 12) based on the determination results of the corresponding determination unit (32). The counting unit (37) counts the number of times a short circuit has occurred in the electrode sheet (5) based on the determination results of the multiple determination units (32).

[0225] With this configuration, by using multiple pairs (G1 to G5) of counter electrodes (11, 12), it is possible to detect multiple (the same number as the multiple pairs (G1 to G5)) of metal foreign objects (F1) of a predetermined size.

[0226] The detection device (1) of the third embodiment further comprises a roller (6) and a drive mechanism (7) as in the second embodiment. The roller (6) is insulating. The roller (6) moves through each detection range (14) of multiple pairs (G1 to G5) of counter electrodes (11, 12). The drive mechanism (7) moves the roller (6) through each detection range (14) of multiple pairs (G1 to G5) of counter electrodes (11, 12) at regular intervals.

[0227] With this configuration, the roller (6) passes over the metal foreign object (F1) that has fallen onto the electrode sheet (5), thereby improving the current flow condition of the short circuit between the first wiring electrode section (11a) and the second wiring electrode section (12a) caused by the metal foreign object (F1). As a result, the metal foreign object (F1) that has fallen onto the electrode sheet (5) can be detected more reliably.

[0228] The detection device (1) of the fourth embodiment comprises, in the first embodiment, a roller (6), a drive mechanism (7), and a counting unit (37). The roller (6) is insulating. The roller (6) moves within the detection range (14) of the pair of opposing electrodes (11, 12). The drive mechanism (7) moves the roller (6) across the detection range (14) of the pair of opposing electrodes (11, 12) at regular intervals. The counting unit (37) counts the number of times a short circuit has occurred in the electrode sheet (5) based on the determination result of the determination unit (32).

[0229] This configuration allows for the detection of multiple metallic foreign objects (F1) using a pair of counter electrodes (11, 12). Because a pair of counter electrodes (11, 12) are used, the number of measurement units (31) and determination units (32) is limited to the number of counter electrodes (11, 12), resulting in cost reduction and miniaturization.

[0230] The detection device (1) of the fifth embodiment further comprises a position measuring unit (36) in the fourth embodiment. The position measuring unit (36) measures the position of the roller (6) within the detection range (14) of a pair of opposing electrodes (11, 12). The determination unit (32) identifies the location of a short circuit determined to have occurred using the measurement result of the position measuring unit (36) at the time of determination. If the identified short circuit location is not the same as a short circuit location already identified, the determination result of the determination unit (32) is made valid. If the identified short circuit location is the same as a short circuit location already identified, the determination result of the determination unit (32) is made invalid.

[0231] With this configuration, the position measuring unit (36) can distinguish whether the short circuit that has occurred is a short circuit that has already occurred.

[0232] The sixth embodiment of the detection device (1) further comprises a time measuring unit (33) in any one of the first to fifth embodiments. The time measuring unit (33) measures the detection time of a short circuit determined to have occurred by the determination unit (32). The detection time is the time from a predetermined point in time to the point in time when the determination unit (32) determines that a short circuit has occurred.

[0233] This configuration allows for the measurement of the time (detection time) it takes to detect a metallic foreign object (F1).

[0234] In the seventh embodiment of the detection device (1), in any one of the first to sixth embodiments, the main surface (13a) of the insulating sheet (13) has a first recess (131) and a second recess (132). The first recess (131) is fitted with a first counter electrode (11). The second recess (132) is fitted with a second counter electrode (12). The first exposed surface (11u) of the first counter electrode (11) is positioned at the same height as the main surface (13a) of the insulating sheet (13) or at a lower height than the main surface (13a). The second exposed surface (12u) of the second counter electrode (12) is positioned at the same height as the main surface (13a) of the insulating sheet (13) or at a lower height than the main surface (13a).

[0235] With this configuration, the current flow of the short circuit between the first counter electrode (11) and the second counter electrode (12) caused by the metal foreign object (F1) can be improved only while the roller (6) is moving over the metal foreign object (F1). Therefore, the location of the short circuit can be distinguished by the position of the roller (6).

[0236] In the eighth embodiment of the detection device (1), in any one of the third to fifth embodiments, the drive mechanism (7) comprises a drive unit (71) and a guide unit (72). The drive unit (71) moves the roller (6). The guide unit (72) moves the roller (6) in a first direction (T1).

[0237] This configuration makes it easy to create a mechanism for moving the roller (6).

[0238] In the detection device (1) of the ninth embodiment, in any one of the first to eighth embodiments, the detection device (1) is positioned around a cutting device that cuts electrode plates which are the material for the electrodes of a lithium-ion battery.

[0239] This configuration allows for the detection of metallic foreign matter (F1) generated during the manufacturing process of lithium-ion battery electrodes.

[0240] The prediction device (100) of the tenth embodiment comprises the detection device (1) of the first embodiment. The electrode sheet (5; 15) of the detection device (1) has a plurality of pairs (G1 to G5) of counter electrodes (11, 12), including the pair of counter electrodes (11, 12) described above. The spacing (s1) between each of the plurality of pairs (G1 to G5) of counter electrodes (11, 12) is of a different size. The insulating sheet (13) of the electrode sheet (5; 15) supports the plurality of pairs (G1 to G5) of counter electrodes (11, 12). The prediction device (100) comprises a time measuring unit (33) and a prediction unit (40). The time measuring unit (33) measures the detection time of a short circuit caused by a metal foreign object (F1) smaller than a predetermined size, which has been determined to have occurred by the determination unit (32). The prediction unit (40) predicts the detection time for a short circuit caused by a metal foreign object (F1) of a predetermined size falling through the air. The detection time is the time from a predetermined point in time until the determination unit (32) determines that a short circuit has occurred. The prediction unit (40) determines the correlation between the spacing (s1) and the detection time for two or more predetermined pairs of counter electrodes (11, 12) among multiple pairs (G1 to G5) of counter electrodes (11, 12) where the spacing (s1) is smaller than a predetermined size, and predicts the detection time for a short circuit caused by a metal foreign object (F1) of a predetermined size based on the determined correlation.

[0241] This configuration allows for the prediction of the detection time for a short circuit caused by a metal foreign object (F1) of a predetermined size (i.e., the detection time for a metal foreign object (F1) of a predetermined size).

[0242] In the prediction device (100) of the eleventh embodiment, as in the tenth embodiment, the prediction device (100) comprises a plurality of measuring units (31) and a plurality of determination units (32). The plurality of measuring units (31) include the measuring unit (31) and correspond to a plurality of pairs (G1 to G5) of counter electrodes (11, 12), and measure the electrical value between the corresponding pairs of counter electrodes (11, 12). The plurality of determination units (32) include the determination unit (32) and correspond to the plurality of measuring units (31), and determine whether or not a short circuit has occurred between the corresponding pairs of counter electrodes (11, 12) based on the measurement results of the corresponding measuring unit (31).

[0243] With this configuration, the short circuits that occur can be easily distinguished by multiple pairs (G1 to G5) of opposing electrodes (11, 12).

[0244] In the prediction device (100) of the twelfth embodiment, in the eleventh embodiment, the installation area of ​​each pair of opposing electrodes (11, 12) of the multiple pairs (G1 to G5) is larger the greater the distance (s1) between the pairs of opposing electrodes (11, 12).

[0245] This configuration allows for more reliable detection of larger metal foreign objects (F1) (i.e., metal foreign objects (F1) that occur infrequently). This configuration assumes that the larger the size of the metal foreign object (F1), the less frequently it occurs.

[0246] The prediction device (100) of the 13th embodiment comprises, in the 10th embodiment, a pair of connected opposing electrodes (18, 19), a roller (6), and a drive mechanism (7). The pair of connected opposing electrodes (18, 19) are formed by connecting the first opposing electrodes (11) to each other and the second opposing electrodes (12) to each other in a plurality of pairs (G1 to G5) of opposing electrodes (11, 12). The roller (6) is insulating. The roller (6) moves within the detection range (16) of the pair of connected opposing electrodes (18, 19). The drive mechanism (7) moves the roller (6) across the detection range (16) of the pair of connected opposing electrodes (18, 19) at regular intervals. The prediction device (100) further comprises a position measuring unit (36). The position measuring unit (36) measures the position of the roller (6) within the detection range (16) of the pair of connected opposing electrodes (18, 19) when the determination unit (32) determines that a short circuit has occurred. The prediction unit (40) identifies the pair in which a short circuit has occurred from a predetermined number of pairs based on the measurement results of the position measuring unit (36), calculates the average time of the short circuit detection time measured by the time measuring unit (33) for each of the predetermined number of pairs, and determines the relative relationship by correlating the interval (s1) between the pairs with the average time.

[0247] With this configuration, by identifying the location of the short circuit based on the position of the roller (6), multiple short circuits can be easily distinguished using a pair of connected opposing electrodes (18, 19). This reduces the number of measuring units (31) and determination units (32) to the number of connected opposing electrodes (18, 19).

[0248] In the prediction device (100) of the 14th embodiment, in the 13th embodiment, in a pair of connected opposing electrodes (18, 19), multiple pairs (G1 to G5) of opposing electrodes (11, 12) are arranged in the direction (T1) in which the roller (6) moves.

[0249] With this configuration, a pair of connected opposing electrodes (18, 19) can be configured so that the location of the short circuit can be easily distinguished by the position of the roller (6).

[0250] In the prediction device (100) of the 15th embodiment, in the 13th or 14th embodiment, the drive mechanism (7) comprises a drive unit (71) and a guide unit (72). The drive unit (71) moves the roller (6). The guide unit (72) moves the roller (6) in one direction.

[0251] With this configuration, the roller (6) can be easily moved.

[0252] In the prediction device (100) of the 16th embodiment, in any one of the 10th to 15th embodiments, the main surface (13a) of the insulating sheet (13) has a plurality of first recesses (131) and a plurality of second recesses (132). The plurality of first recesses (131) correspond to a plurality of pairs (G1 to G5) of counter electrodes (11, 12), and the first counter electrode (11) of the corresponding pair of counter electrodes (11, 12) is fitted into each of the first recesses (131). The plurality of second recesses (132) correspond to a plurality of pairs (G1 to G5) of counter electrodes (11, 12), and the second counter electrode (12) of the corresponding pair of counter electrodes (11, 12) is fitted into each of the second recesses (132). The first exposed surface (11u) of the first counter electrode (11) is positioned at the same height as the main surface (13a) of the insulating sheet (13) or at a lower height than the main surface (13a). The second exposed surface (12u) of the second opposing electrode (12) is positioned at the same height as the main surface (13a) of the insulating sheet (13) or at a lower height than the main surface (13a).

[0253] With this configuration, the current flow of the short circuit caused by the metal foreign object (F1) can be improved only while the roller (6) is on the metal foreign object (F1). This makes it easy to distinguish the location of the short circuit that has occurred based on the position of the roller (6).

[0254] The detection method of the 17th embodiment includes a measurement step (ST3) and a determination step (ST4). In the measurement step (ST3), the electrical value between a pair of counter electrodes (11, 12) of an electrode sheet (5) is measured. The electrode sheet (5) has a pair of counter electrodes (11, 12) and an insulating sheet (13). The pair of counter electrodes (11, 12) includes a first counter electrode (11) and a second counter electrode (12). The insulating sheet (13) supports the pair of counter electrodes (11, 12). The first counter electrode (11) has a plurality of first wiring electrode portions (11a), and the second counter electrode (12) has a plurality of second wiring electrode portions (12a). The plurality of second wiring electrode portions (12a) are arranged alternately with the plurality of first wiring electrode portions (11a) at intervals. In the determination step (ST4), based on the measurement results from the measurement step (ST3), it is determined whether or not a short circuit has occurred between the pair of counter electrodes (11, 12) due to a metal foreign object (F1) falling through the air.

[0255] This configuration allows for the detection of metallic foreign objects (F1) falling through the atmosphere. More specifically, it allows for the detection of metallic foreign objects (F1) of a size corresponding to the distance (s1) between the pair of opposing electrodes (11, 12).

[0256] The prediction method of the 18th embodiment includes the detection method of the 17th embodiment. The electrode sheet (15) in the above detection method has a plurality of pairs (G1 to G5) of counter electrodes (11, 12), including a pair of counter electrodes (11, 12). The spacing (s1) between each of the plurality of pairs (G1 to G5) of counter electrodes (11, 12) is of a different size. The insulating sheet (13) of the electrode sheet (15) supports the plurality of pairs (G1 to G5) of counter electrodes (11, 12). The prediction method further comprises a time measurement step (ST37) and a prediction step (ST41). In the time measurement step (ST37), the detection time of a short circuit caused by a metal foreign object (F1) smaller than a predetermined size, which has been determined to have occurred by the determination step (ST34), is measured. In the prediction step (ST41), the detection time of a short circuit caused by a metal foreign object (F1) of a predetermined size falling through the air is predicted. The detection time is the time from a predetermined point in time until the determination step (ST34) determines that a short circuit has occurred. In the prediction step (ST41), the correlation between the spacing (s1) and the detection time is determined for two or more predetermined pairs of counter electrodes (11, 21) among multiple pairs (G1 to G5) where the spacing (s1) is smaller than a predetermined size, and the detection time is predicted based on the determined correlation.

[0257] This configuration allows for the detection time of a short circuit caused by a metal foreign object (F1) of a predetermined size (i.e., the detection time of a metal foreign object (F1) of a predetermined size).

[0258] 1 Detection device 5, 15 Electrode sheet 6 Roller 7 Drive mechanism 11a First wiring electrode section 11u Exposed surface (first exposed surface) 12u Exposed surface (second exposed surface) 13a First main surface (main surface) 12a Second wiring electrode section 13 Insulating sheet 14, 16 Detection range 31 Measurement section 32 Judgment section 37 Counting section 36 Position measurement section 131 First recess 132 Second recess 100 Prediction device G1 to G5 Pair s1 Interval T1 First direction

Claims

1. A detection device comprising: an electrode sheet having a pair of counter electrodes including a first counter electrode and a second counter electrode, and an insulating sheet supporting the pair of counter electrodes, wherein the first counter electrode has a plurality of first wiring electrode portions, and the second counter electrode has a plurality of second wiring electrode portions arranged alternately with the plurality of first wiring electrode portions at intervals; a measuring unit for measuring electrical values ​​between the pair of counter electrodes; and a determination unit for determining whether or not a short circuit has occurred between the pair of counter electrodes due to a metallic foreign object falling in the atmosphere, based on the measurement results of the measuring unit.

2. The electrode sheet has a plurality of pairs of counter electrodes, including the pair of counter electrodes, and the spacing between each of the plurality of pairs of counter electrodes is the same, and the detection device includes a plurality of measuring units, which include a measuring unit and correspond to the plurality of pairs of counter electrodes, and measure the electrical value between the corresponding pairs of counter electrodes; a plurality of determination units, which include a determination unit and correspond to the plurality of measuring units, and determine whether or not a short circuit has occurred between the corresponding pairs of counter electrodes based on the measurement results of the corresponding measuring units; and a counting unit, which counts the number of times the short circuit has occurred in the electrode sheet based on the determination results of the plurality of determination units, as described in claim 1.

3. The detection device according to claim 2, further comprising: an insulating roller that moves through the detection range of each of the plurality of pairs of counter electrodes; and a drive mechanism that moves the roller across the detection range of each of the plurality of pairs of counter electrodes at regular intervals.

4. The detection device according to claim 1, comprising: an insulating roller that moves within the detection range of the pair of opposing electrodes; a drive mechanism that moves the roller across the detection range of the pair of opposing electrodes at regular intervals; and a counting unit that counts the number of times the short circuit occurs in the electrode sheet based on the determination result of the determination unit.

5. The detection device according to claim 4, further comprising a position measuring unit for measuring the position of the rollers of the pair of opposing electrodes within the detection range, wherein the determination unit identifies the location of the short circuit determined to have occurred by the determination unit using the measurement result of the position measuring unit at the time of determination, and if the identified location of the short circuit is not the same as a short circuit already identified, the determination result of the determination unit is made valid, and if the identified location of the short circuit is the same as a short circuit already identified, the determination result of the determination unit is made invalid.

6. The detection device according to any one of claims 1 to 5, further comprising a time measuring unit for measuring the detection time of the short circuit determined to have occurred by the determination unit, wherein the detection time is the time from a predetermined point in time to the point in time when the determination unit determined that the short circuit had occurred.

7. The detection device according to any one of claims 1 to 6, wherein the main surface of the insulating sheet has a first recess into which the first opposing electrode is fitted and a second recess into which the second opposing electrode is fitted, the first exposed surface of the first opposing electrode is positioned at the same height as the main surface of the insulating sheet or at a height lower than the main surface, and the second exposed surface of the second opposing electrode is positioned at the same height as the main surface of the insulating sheet or at a height lower than the main surface.

8. The detection device according to any one of claims 3 to 5, wherein the drive mechanism comprises a drive unit for moving the roller and a guide unit for moving the roller in a first direction.

9. The detection device according to any one of claims 1 to 8, wherein the detection device is arranged around a cutting device that cuts electrode plates which are the material for the electrodes of a lithium-ion battery.

10. A prediction device comprising the detection device according to claim 1, wherein the electrode sheet of the detection device has a plurality of pairs of counter electrodes, including the pair of counter electrodes, the spacing between each of the plurality of pairs of counter electrodes is of a different size from one another, the insulating sheet of the electrode sheet supports the plurality of pairs of counter electrodes, the prediction device further comprises: a time measuring unit for measuring the detection time of the short circuit caused by the metal foreign object of a size smaller than a predetermined size, which has been determined to have occurred by the determination unit; and a prediction unit for predicting the detection time of the short circuit caused by the metal foreign object of a predetermined size falling through the atmosphere, wherein the detection time is the time from a predetermined time to the time when the determination unit determines that the short circuit has occurred, and the prediction unit determines a correlation between the spacing between two or more predetermined pairs of counter electrodes among the plurality of pairs of counter electrodes, where the spacing between them is smaller than the predetermined size, and the detection time, and predicts the detection time of the short circuit caused by the metal foreign object of a predetermined size based on the determined correlation.

11. The prediction device according to claim 10, comprising: a plurality of measuring units, each including the measuring unit, corresponding to the plurality of pairs of counter electrodes, and measuring the electrical value between the corresponding pairs of counter electrodes; and a plurality of determining units, each including the determining unit, corresponding to the plurality of measuring units, and determining whether or not a short circuit has occurred between the corresponding pairs of counter electrodes based on the measurement results of the corresponding measuring units.

12. The prediction device according to claim 11, wherein the installation area of ​​each of the plurality of pairs of counter electrodes is larger the greater the distance between the pairs of counter electrodes.

13. The prediction device according to claim 10, comprising: a pair of connected opposing electrodes in which the first opposing electrodes of a plurality of pairs are connected to each other and the second opposing electrodes are connected to each other; an insulating roller that moves within the detection range of the pair of connected opposing electrodes; and a drive mechanism that moves the roller within the detection range of the pair of connected opposing electrodes at regular intervals, wherein the prediction device further comprises a position measuring unit that measures the position of the roller within the detection range of the pair of connected opposing electrodes when the determination unit determines that the short circuit has occurred, and the prediction unit identifies the pair in which the short circuit has occurred from a predetermined number of pairs based on the measurement result of the position measuring unit, calculates the average time of the detection time of the short circuit measured by the time measuring unit for each of the predetermined number of pairs, and calculates the correlation by relating the interval of the pair to the average time.

14. The prediction device according to claim 13, wherein in the pair of connected opposing electrodes, the plurality of pairs of opposing electrodes are arranged in the direction in which the roller moves.

15. The prediction device according to claim 13 or 14, wherein the drive mechanism comprises a drive unit for moving the roller and a guide unit for moving the roller in one direction.

16. The main surface of the insulating sheet has a plurality of first recesses corresponding to the plurality of pairs of opposing electrodes into which the first opposing electrode of the corresponding pair of opposing electrodes is fitted, and a plurality of second recesses corresponding to the plurality of pairs of opposing electrodes into which the second opposing electrode of the corresponding pair of opposing electrodes is fitted, the first exposed surface of the first opposing electrode is positioned at the same height as the main surface of the insulating sheet or at a height lower than the main surface, and the second exposed surface of the second opposing electrode is positioned at the same height as the main surface of the insulating sheet or at a height lower than the main surface, the prediction device according to any one of claims 10 to 15.

17. A detection method comprising: a measurement step of measuring an electrical value between the pair of opposing electrodes of an electrode sheet having a pair of opposing electrodes including a first opposing electrode and a second opposing electrode, wherein the first opposing electrode has a plurality of first wiring electrode portions, and the second opposing electrode has a plurality of second wiring electrode portions arranged alternately with the plurality of first wiring electrode portions at intervals; and a determination step of determining whether or not a short circuit has occurred between the pair of opposing electrodes due to a metallic foreign object falling into the atmosphere, based on the measurement result of the measurement step.

18. A prediction method comprising the detection method according to claim 17, wherein the electrode sheet in the detection method has a plurality of pairs of counter electrodes, including the pair of counter electrodes, the spacing between each of the plurality of pairs of counter electrodes is of a different size from one another, the insulating sheet of the electrode sheet supports the plurality of pairs of counter electrodes, the prediction method further comprises: a time measurement step of measuring the detection time of the short circuit caused by the metal foreign object of a size smaller than a predetermined size, which has been determined to have occurred by the determination step; and a prediction step of predicting the detection time of the short circuit caused by the metal foreign object of a predetermined size falling through the atmosphere, wherein the detection time is the time from a predetermined time to the time when the determination step determines that the short circuit has occurred, and in the prediction step, a correlation is found between the spacing between two or more predetermined pairs of counter electrodes, where the spacing between them is smaller than the predetermined size, and the detection time, and the detection time of the short circuit caused by the metal foreign object of a predetermined size is predicted based on the found correlation.

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