Inspection assembly for the energy cell-producing industry

Abstract

The invention relates to an inspection assembly for the energy cell-producing industry, comprising at least one inspection device (10) for optically inspecting a flat element (50), which is conveyed in a machine (13), and an electronic analysis unit (60), which is designed to process data transmitted from the inspection device (10). At least one first part (56) of the inspection device (10) is arranged in a measurement relationship with a first surface of a conveyed flat element (50), and at least one second part (57) of the inspection device (10) is arranged in a measurement relationship with a second surface of the conveyed flat element (50), said second surface lying opposite the first surface.

Description

[0001] Inspection order for the

[0002] Energy cell producing industry

[0003] The invention relates to an inspection arrangement for the energy cell producing industry, comprising an inspection device for optically inspecting a planar element conveyed in a machine, and comprising an electronic evaluation unit configured to process data transmitted by the inspection device, wherein at least a first part of the inspection device is arranged in a measuring relationship to a first surface of a conveyed planar element.

[0004] For the final inspection of electrode-separator composite elements, such as monocells, a visual inspection is advantageous. In particular, defects that arise during the manufacturing of a composite element, for example, through lamination or general bonding, should be detected. During the manufacturing of an electrode-separator composite element, in addition to contamination, defects such as wrinkles, bubbles, or cracks can also occur. These are often only visible under certain lighting conditions.

[0005] The flat elements to be inspected also include web material, especially electrode webs and separator film webs. During surface inspection, the web material should be checked for various defects or anomalies. These include, for example, foreign bodies, edge chipping, edge tears, holes, cracks, and scratches. Due to the combination of the high web speed, the small size of the defects, the very dark color of the electrode material, and the sometimes low brightness contrast with the background, reliable detection is difficult.

[0006] The structure of electrode-separator composite elements, such as monocells, can be designed such that the larger anode is exposed on one side and the smaller cathode is concealed behind a separator foil. This design significantly complicates both X-ray scanning and one-sided measurement.

[0007] Flat light tables are typically used for geometric measurements of flat elements using a camera. In the energy cell manufacturing industry, flat elements, such as electrode-separator composite elements, especially monocells, are transported on drums or, more generally, rotary conveyors. X-raying drums or rotary conveyors is very complex and error-prone, for example, due to contamination. In addition, the reflectivity of the drums is usually very high. The curvature of drums is unfavorable for measurement.

[0008] The object of the invention is to provide a comparatively simple inspection arrangement with which flat elements of the energy cell producing industry, in particular electrode-separator composite elements and web materials, can be measured and inspected comprehensively and with high accuracy under production conditions.

[0009] The invention solves this problem with the features of the independent claims. According to the invention, at least a second part of the inspection device is arranged in a measuring relationship with a second surface of a conveyed flat element, opposite the first surface. The invention enables the complete inspection of the flat elements on both sides, in particular electrode-separator composite elements and web materials, and the detection of contamination, defects, foreign bodies, and other anomalies. The invention also enables the geometry measurement of electrode-separator composite elements, in particular in the case of a cathode concealed by the anode.

[0010] The invention can be easily implemented in that preferably the first part and the second part of the inspection device each comprise a camera.

[0011] In the case of a conveying device with rotary conveyors, it is advantageous for a first camera to be arranged in a measuring relationship with a first rotary conveyor and the second camera to be arranged in a measuring relationship with a subsequent second rotary conveyor. In this case, the second rotary conveyor can advantageously be configured to transport the flat elements with a reversed surface relative to the first rotary conveyor, which enables inspection or measurement of the flat elements from both sides, in particular of electrode-separator composite elements. Transport with a reversed surface is achieved without further measures if, preferably, the first rotary conveyor and the second rotary conveyor are arranged either directly following one another or separated from one another by an even number of rotary conveyors.

[0012] In one embodiment, the cameras are configured for optical surface inspection of the planar element on both sides and the evaluation unit is configured for error detection by means of image processing, which enables the detection of contamination, errors, foreign bodies and other anomalies of the planar elements, such as edge chipping, holes, cracks and scratches.

[0013] In applications where the planar element is an electrode-separator composite element, the first camera is advantageously configured to inspect a first electrode and the second camera is advantageously configured to inspect a second electrode in the electrode-separator composite element. In this case, the electronic evaluation unit is advantageously configured to determine the position of the first electrode relative to a separator, the position of the second electrode relative to a separator, and / or the relative position between the first and second electrodes in the electrode-separator composite element.

[0014] Preferably, the inspection device is configured to capture a plurality of individual images corresponding to successive positions of the conveyor device, and the data processing device is configured to generate an overall image comprising at least one planar element from the plurality of individual images by image processing. By partially capturing comparatively small sections, the problem of drum curvature can be significantly reduced. The images are taken staggered in time with the movement of the drum. The partial images or individual images are then combined to form an overall image and evaluated.

[0015] The individual images can overlap slightly, which facilitates analysis and ensures a seamless overall image along the conveying direction. It is also conceivable for the individual images to be taken without overlap and without spacing, or with a small spacing between them.

[0016] Preferably, the dimension of each individual image along the conveying direction is smaller than the dimension of a planar element along the conveying direction. The imaging of a planar element is achieved by combining a plurality of individual images, each of which depicts only a portion of the planar element.

[0017] Advantageously, a camera is provided on each of the two opposite sides of the conveyor device. This is based on the realization that the central area of ​​the flat elements does not necessarily need to be measured to determine the geometry, and it is sufficient to measure the lateral areas of the flat elements in the area of ​​the side edges (relative to the conveying direction). The or each camera can then be adapted to measure a lateral area of ​​the flat elements and, in particular, can be designed to be smaller than would be required to capture the entire flat element, which significantly reduces costs.

[0018] Preferably, the width b of an individual image along a conveying direction of the conveying device designed as a rotary conveyor is a maximum of 2 > / (r 2 - (r-d) 2), where r is the radius of the rotary conveyor and d is the depth of field of the inspection device or camera. Using this dimensioning rule, an overall image with a depth of field at every point can be achieved by composing a plurality of individual images. The conveying direction is generally the circumferential direction of the rotary conveyor.

[0019] The inspection arrangement preferably has at least one illumination device for illuminating at least one measuring field of the inspection device. The illumination makes the outline of the planar element, in particular the electrode-separator composite element, more visible. Advantageously, each camera is assigned at least one separate illumination device, which enables targeted illumination and a reduction in the dimensions of the illumination devices. The at least one illumination device can advantageously be controlled by the evaluation unit for image acquisition.

[0020] The illumination device preferably uses light of a suitable wavelength, particularly with regard to the transillumination of the separator film of the electrode-separator composite element, in order to better inspect or measure the electrode located beneath the separator, in particular the cathode. The illumination device is therefore preferably configured to generate red light with a wavelength between 600 nm and 1100 nm, preferably between 650 nm and 950 nm, and more preferably between 700 nm and 800 nm. These wavelength ranges have a high transmission through the separator film and are therefore particularly advantageous for transilluminating it.

[0021] Advantageously, the illumination device can also be designed to generate polarized light; in this case, a blocking filter or polarization analyzer is advantageously provided.

[0022] In a preferred embodiment, the illumination device has a beam axis coaxial with an optical axis of the inspection device. Such coaxial illumination enables precise measurement despite the reflective outer surface of the rotary conveyor. In this embodiment, the illumination device preferably has a beam splitter for redirecting the light generated by a light source parallel to the optical axis of the inspection device.

[0023] In another advantageous embodiment, the illumination device has a beam axis that is oblique to the optical axis of the inspection device. Preferably, the or each camera is assigned a plurality of illumination devices that illuminate the camera's measuring field from different sides with beam axes that are oblique to the camera's optical axis and mutually non-parallel. Thus, illumination adapted to the partial recording, advantageously at different angles to the flat element, is preferred. In this way, shadow formation, in particular due to surface irregularities of the flat element, can be prevented. The above embodiment can be used advantageously, particularly when the rotary conveyor has a rough outer surface.

[0024] In one embodiment of the invention, the planar element is a material web. The planar element can, in particular, be a separator web. In this case, the first part of the inspection device is advantageously a camera, and the second part of the inspection device is advantageously an illumination device to enable inspection of the separator web using the transmitted light method.

[0025] The invention further provides a machine for the energy cell production industry that is configured to convey flat elements. According to the invention, the machine comprises an inspection arrangement as described above, which is arranged in a measuring relationship with the conveyed flat elements.

[0026] In one embodiment of the invention, the inspection device is arranged downstream of a connecting device of the machine, in particular for the double-sided inspection or measurement of electrode-separator composite elements produced in the connecting device.

[0027] In one embodiment of the invention, the inspection device is arranged in a feed section of the machine, in particular for inspecting a material web fed into the feed section. This can be an electrode web to be inspected on both sides or a separator web to be inspected using the transmitted light method.

[0028] The planar element is, in particular, an electrode-separator composite element, for example, a monocell with anode, separator, cathode, and separator. The planar element can also be a material web from the energy cell manufacturing industry, in particular an electrode web or a separator web. The conveyor device is, in particular, a rotary conveyor, for example, a conveyor drum for a machine for manufacturing energy cells. The invention is explained below using preferred embodiments with reference to the attached figures.

[0029] Fig. 1 is a schematic view of a machine for producing battery cells in detail;

[0030] Fig. 2 is a schematic view of a machine for producing battery cells in a section following Figure 1;

[0031] Fig. 3 a schematic cross-section through a flat element in the form of a monocell,

[0032] Fig. 4 shows part of an inspection device in a longitudinal section through a rotary conveyor;

[0033] Fig. 5 shows the dividing device according to Fig. 4 in a plan view of a lateral surface of the rotary conveyor;

[0034] Fig. 6 is a plan view of a planar element to illustrate image acquisition by the dividing device;

[0035] Fig. 7 is a schematic cross-sectional view through a rotary conveyor;

[0036] Fig. 8 shows a part of an inspection device in a longitudinal section through a rotary conveyor in a further embodiment; and Fig. 9 shows the partial device according to Fig. 8 in a plan view of a lateral surface of the rotary conveyor.

[0037] A machine 13 for producing battery cells is shown in sections in Figures 1 and 2. The machine 13 comprises a feed section 23 for feeding starting materials, namely endless separator webs 81, 83 and endless electrode webs 82, 84, to subsequent machine sections 24, 14.

[0038] The feed section 23 comprises an electrode feed section 24 for producing and feeding individual electrode sheets or electrodes from the electrode tracks 82, 84. The electrode feed section 24 has a first electrode manufacturing device 19 for producing first electrodes, for example cathodes, and a second electrode manufacturing device 18 for producing second electrodes, for example anodes.

[0039] The electrode production devices 18, 19 each have a rotating cutting device 20 for cutting the fed electrode web 82, 84 into individual electrodes. The cutting device 20 comprises a knife shaft 21 and a cutting drum 22. The knife shaft 21 is equipped with knives along its circumference, which engage in grooves of the cutting drum 22 to cut the electrode web 82, 84. Downstream of the cutting device 20, a pitch-changing drum 26 can be provided, which serves to provide the cut electrodes with a spacing from one another in the longitudinal direction.

[0040] Furthermore, each electrode manufacturing device 18, 19 comprises a transfer device 27 for transferring the cut electrodes to a subsequent conveyor device 14. The conveyor device 14 is designed, for example, as a belt conveyor and advantageously has a conveying means 16, in particular an endlessly circulating conveyor belt. The conveyor device 14 can also be designed as a conveyor drum.

[0041] The transfer device 27 comprises a transfer drum 28 and a guide device which comprises a guide belt 15 which continuously rotates around the transfer drum 28 and an auxiliary roller 17. The transfer drum 28 receives the electrodes from an upstream drum, here the pitch change drum 26, and places them on the conveyor 16 of the conveyor device 14. The electrodes are conveyed on the conveyor 16 from left to right in Figure 1, with the guide belt 15 running above the conveyor 16 so that the electrodes are guided between the conveyor 16 and the guide belt 15. First, the first electrodes produced by the first electrode production device 19 are placed on the conveyor 16 by means of the corresponding transfer device 27. Then, immediately behind the auxiliary roller 17, the first separator web 83 is placed over the first electrodes onto the conveyor 16 by means of a deflection roller 32.The second electrodes produced by the second electrode production device 18 are then deposited on the conveyor 16 by means of the corresponding transfer device 27, with a second electrode being precisely positioned over a first electrode. Subsequently, immediately behind the corresponding auxiliary roller 17, the further separator web 81 is placed over the second electrodes onto the conveyor 16 by means of a deflection roller 33.

[0042] The conveyor device 14 therefore serves to superimpose the materials: first electrode, first separator web 83, second electrode, and further separator web 81, thereby forming an electrode-separator material formation. The electrode-separator material formation then passes through a connecting device 25, for example a laminating device with one or more laminating rollers 29 (see Figure 2), in order to connect the layers of the electrode-separator material formation to one another and form an electrode-separator composite web 34. The connecting device 25 can have a preheating device 35 arranged upstream of the laminating roller 29 for preheating the electrode-separator material formation prior to lamination.The connecting device 25 can also have an upper conveyor 36, in particular a conveyor belt, so that the electrode-separator material formation is held between the lower conveyor 16 and the upper conveyor 36 during lamination. A cooling device 39, in particular a cooling drum, can be provided adjacent to the connecting device 25 to remove heat from the process introduced into the production stream by the connecting device 25, in particular the laminating rollers 29. The cooling device 39 can be cooled, for example, electrically or by passing a cooling medium through it, in order to specifically extract heat from the warm composite web 34.

[0043] The machine 13 has a cutting device 37 arranged downstream of the connecting device 25 for cutting the electrode-separator composite web 34 into electrode-separator composite elements, in particular monocells, and a stacking station 48, shown only schematically, for stacking the electrode-separator composite elements, in particular monocells, into a cell stack. The machine section between the connecting device 25 and the stacking station 48 is referred to below as the testing and separating section 38. Between the connecting device 25 and the cutting device 37, an advantageously linear testing section 43 can be provided, which has one or more testing devices 44, in particular for testing the positions of the anodes and cathodes in the composite web 34. For example, one or more optical testing devices, such as one or more cameras, can be provided. At this point, iein the area of ​​test track 43, there is also a sequence of several drums on which additional functions can be implemented if required.

[0044] By means of the cutting device 37, the composite web 34 is cut into individual separator-electrode composite elements 91, preferably in an electrode-free area, thereby producing monocells as shown in Figure 3. A monocell is a layer system consisting of superimposed layers, namely a separator 92, an anode 93, a further separator 94, and a cathode 95. To construct a monocell stack, several or a plurality of these monocells are stacked one on top of the other and closed off with a terminal cell. The cell stack is used in particular to construct an electrochemical and / or galvanic accumulator (not shown), for example, a lithium-ion battery. The electrodes 93, 95 consist of typical electrode materials of an electrochemical and / or galvanic accumulator cell. In the case of a lithium-ion cell, the electrodes contain, for example, lithium ions.The separators serve to electrically insulate the electrodes from one another and are made, for example, of a plastic film, such as a thermoplastic material. The cutting device 37 is advantageously constructed similarly to the cutting devices 20, 20' and preferably comprises a cutting drum 45 with grooves over which the composite web 34 is guided, and a knife roller 46 with knives that cuts the composite web 34 tangentially to the cutting drum 45 and by engaging the knives in the grooves as a result of the coordinated rotation of both drums 45, 46.

[0045] The testing and separation section 38 preferably comprises a downstream rotary conveyor 47, for example, a testing drum, on which the electrical properties of the individual composite elements 91 or monocells can be measured using a suitable testing device. For example, a test of the geometric shape of the electrodes 93, 95 and / or the electrical resistance of the composite elements 91 can be performed.

[0046] A further rotary conveyor 49, for example a transport drum, can be provided adjacent to the rotary conveyor 47. A subsequent drum system of a stacking station 48 (not shown in the figures) serves to stack the composite elements 91 or monocells into a monocell stack.

[0047] An inspection arrangement with an inspection device 10 for inspecting, in particular for geometric measurement and / or surface testing, flat elements 50, here composite elements 91 or monocells, is shown in Figure 2. In this embodiment, the conveying device 40 is formed by rotary conveyors 47, 49. A first part 56 of the inspection device 10 comprises at least one camera 11 and is arranged in a measuring relationship to a first conveying part 59 of the conveying device 40, in particular a rotary conveyor 47. A second part 57 of the inspection device 10 comprises at least one camera 11 and is arranged in a measuring relationship to a second conveying part 62 of the conveying device 40, in particular a rotary conveyor 49.

[0048] The parts 56, 57 of the inspection device 10 are arranged such that they can inspect opposite surfaces 63, 64 (see Figure 3) of the planar element 50, here the composite element 91. This can advantageously be achieved by arranging the parts 56, 57 of the inspection device 10 in measuring relationship to immediately successive rotary conveyors 47, 49, as in Figure 2, whereby the planar element 50 is turned from one rotary conveyor 47 to the immediately following rotary conveyor 49. Embodiments with an even number of further rotary conveyors arranged between the rotary conveyors 47, 49, and / or one or more linear conveyors arranged between the rotary conveyors 47, 49, which do not change the orientation of the planar element, are also conceivable.

[0049] Due to the detection of both opposing surfaces 63, 64 of the planar element 50, a complete inspection of the entire planar element 50 is advantageously possible, which enables the detection of contamination, defects, foreign bodies and other anomalies of the planar elements, such as edge chipping, holes, cracks and scratches, on the entire surface of the planar element 50.

[0050] The arrangement of the inspection device 10 is not limited to the arrangement shown in Figure 2 in measuring relationship to the rotary conveyors 47, 49. For example, the first part 56 of the inspection device 10 could be arranged in measuring relationship to a rotary conveyor of the cutting device 37, for example, the cutting drum 45, and the second part 57 of the inspection device 10 could be arranged in measuring relationship to an immediately following rotary conveyor 47.

[0051] It is also possible to arrange the inspection device 10 in the area upstream of the cutting device 37, for example, in the area of ​​the linear test section 43. In this case, the measurement is performed on the composite elements 91 in the composite web 34 that have not yet been separated. The first part 56 and the second part 57 of the inspection device 10 are arranged on opposite sides of the composite web 34 in this case.

[0052] The inspection device 10 can also be used to measure the geometry of a planar element 50 or individual layers therein, for example, the electrode sheets 93, 95 in the composite element 91. Advantageous embodiments of the inspection device 10, which are particularly suitable for geometry measurement, alternatively or additionally also for surface inspection of a planar element 50, are explained below with reference to Figures 4 to 9.

[0053] The measurement of the geometry of a planar element 50 comprises, in particular, the determination of the contour 51 of the planar element 50, or of individual layers 93, 95 therein, in a plan view of the planar extension, as in Figure 5, for example. This contour 51 is, for example, substantially rectangular and has, in the conveying direction, a leading edge 54, a trailing edge 55, and two side edges 53. A conductor lug 52 can be provided, in particular laterally, on an electrode sheet 93, 95, which serves to electrically connect all cathodes and all anodes in the finished cell stack to one another.

[0054] To measure the geometry of the planar element 50, each part 56, 57 of the inspection device 10 has at least one, preferably at least two cameras 11, which are arranged facing the corresponding conveyor part 59, 62 of the conveyor device 40. In the following, without limiting the generality, an advantageous embodiment of the first part 56 of the inspection device 10 with reference to the first conveyor part 59 (rotary conveyor 47) of the conveyor device 40 is considered and explained with reference to Figures 4 to 9. The corresponding explanations can be readily transferred to the second part 57 of the inspection device 10 with reference to the second conveyor part 62 of the conveyor device 40.

[0055] If the first conveying part 59 of the conveying device 40 is a rotary conveyor 47, as in Figure 2, the at least one camera 11 is arranged with a view towards a lateral surface 41 of the rotary conveyor 47, preferably with a radial view relative to the rotation axis R. With respect to the center plane M of the rotary conveyor 47, which is perpendicular to the rotation axis R, several, here two, cameras 11 are preferably arranged laterally offset. Advantageously, at least one camera 11 is arranged on each side of the center plane M of the rotary conveyor 47. Preferably, each camera 11 is configured and arranged to capture an area around a respective side edge 53 of the planar element 50. If the planar element 50, or a layer therein, has a lateral collector lug 52, a camera 11 is configured and arranged to completely capture the collector lug 52.

[0056] The or each of the two cameras 11 is configured to capture a strip- or line-shaped individual image 30. The longitudinal extent of the individual image 30 runs perpendicular to the conveying direction F or perpendicular to the center plane M of the rotary conveyor 47. The length L of each individual image 30 results from the requirement that a sufficiently large area around the respective side edge 53 or around the conductor lug 52 can be captured by the camera 11. The width b of each individual image 30 is preferably significantly smaller than the width B of a planar element 50 if, due to the curvature of the casing 41 of the rotary conveyor 47 and a given depth of field d of the camera 11, a sharp image of the planar element 50 across its entire width cannot be achieved. This will be explained in more detail below.

[0057] As a result of the rotation of the rotary conveyor 40 about the rotation axis R, comparatively narrow individual images 30 can be successively captured with the cameras 11. Image capture is controlled by an electronic evaluation unit 60 (see Figure 5) depending on the rotational position of the rotary conveyor 47, which may be known, for example, from a position-controlled drive of the rotary conveyor 47, or depending on a machine cycle.

[0058] In the electronic evaluation unit 60, image processing of the individual images 30 transmitted by the cameras 11 takes place. The individual images 30 of a camera 11 corresponding to a planar element 50 are combined to form an overall image 31, see Figure 6. In this way, a complete image can be obtained in the area of ​​both side edges 53 of the planar element 50, including the conductor lug 52.

[0059] In Figure 6, the individual images 30 captured by a camera 11 are shown at a small distance from each other for clarity. However, the individual images 30 can also be captured by a camera 11 with an overlap in the conveying direction F, or adjacent to each other without a gap.

[0060] From the overall image(s) 30, the contour 51 of the planar element 50, or of a layer 93, 95 therein, can be determined by image processing in the electronic evaluation unit 60. The contour in the central region of the planar element 50 can be interpolated with high accuracy, so that taking an image in the central region of the planar element 50 is not necessary.

[0061] The dimensioning of the width b of an individual image 30 is explained below with reference to Figure 7. This shows a cross-section through the, for example, cylindrical rotary conveyor 47 in a section. The rotary conveyor 47 has a radius r. The camera 11 has a depth of field d. The maximum width b of an individual image 30 is then b = 2 > / (r 2 - (r-d) 2). If the width of the individual image 30 is selected to be less than or equal to b, a high degree of sharpness of the overall image 31 over the entire width B of the flat element 50 can be achieved despite the curvature of the rotary conveyor 47 in cross-section. Of course, this consideration depends on the width of an individual image 30 in the overall image 31. This means that it is possible to record an individual image with a width > b; subsequently, one or more edge strips of the recorded individual image can be cut off by image processing in order to fulfill the condition: width of the individual image 30 < b. The camera 11 can be a line scan camera or a matrix camera, for example. The light-sensitive sensor of the camera 11 can be line- or strip-shaped. However, the light-sensitive sensor of the camera 11 can also have a different shape.In this case, an individual image 30, for example in the form of a strip or line, can be cut out of a larger recorded image by image processing.

[0062] The inspection arrangement advantageously comprises at least one illumination device 70 for illuminating at least one measuring field of the inspection device 10. Preferably, at least two illumination devices 70 are provided, each illumination device 70 being configured to illuminate a measuring field of a camera 11. The illumination device 70 is therefore arranged and configured such that a light beam 71 generated by the illumination device 70, optionally after deflection, falls onto a planar element 50 conveyed by the conveyor device 40 through the field of view of the camera 11 in order to illuminate the planar element 50. Due to the illumination by the at least one illumination device 70, the quality of the images recorded by the corresponding camera 11 can be significantly improved.

[0063] Each lighting device 70 has a light source 72 for generating the light beams 71. The light source 72 can, for example, be an LED light source, in particular in the form of an LED array or an LED matrix.

[0064] In the advantageous embodiment according to Figures 4 and 5, a coaxial illumination device 70 is provided. This means that the light beam incident on the flat element 50 or on the outer surface of the rotary conveyor 47, 49 runs coaxially or parallel to the viewing direction or the optical axis 12 of the camera 11. This is achieved by means of a beam splitter 73, which deflects the light beam 71 generated by the light source 72, for example incident laterally, by 90°, for example, so that the deflected light beam 71 then runs parallel to the optical axis 12 of the camera 11. The optical axis 12 of the camera 11 runs through the beam splitter 73, as shown in Figure 1.The coaxial illumination device 70 can have a diffuser arranged between the light source 72 and the beam splitter 73 in order to standardize or homogenize the light pattern generated by individual light-generating elements, such as LEDs, in the light source 72. A camera 11 and an associated illumination device 70 can advantageously be combined into a single structural unit to form a measurement unit.

[0065] In a further advantageous embodiment according to Figures 8 and 9, the illumination device 70 is configured to generate a light beam 71 incident obliquely on the lateral surface 41 of the rotary conveyor 47, 49 or on the planar element 50. In this embodiment, a beam splitter 73 is unnecessary.

[0066] To avoid shadows caused by unevenness of the planar element 50, three light sources 72 are preferably provided on each side of the rotary conveyor 44, 49 or the planar element 50 (see Figure 9), with one light source 72 radiating obliquely from the front, i.e., from the front edge 54, one light source 72 radiating obliquely from the rear, i.e., from the rear edge 55, and another light source 72 radiating obliquely from the respective side edge 53. In a composite element 91, one electrode (anode 93 in Figure 3) is generally covered on the outside by a separator 92. The illumination device 70, which is assigned to the corresponding part 57 of the inspection device 10, which is arranged for measuring the surface 63 with the separator 92 directed outwards, is therefore preferably designed to generate light with a wavelength that has a high transmission through the separator film 92 in order to be able to illuminate it as smoothly as possible.Red light is particularly suitable in this respect, in particular with a wavelength between 600 nm and 1100 nm, preferably between 650 nm and 950 nm, more preferably between 700 nm and 800 nm. The use of polarized light, optionally with a barrier filter or polarization analyzer, can also be advantageous.

[0067] The inspection arrangement is not limited to the inspection of the electrode-separator composite track 34 or of electrode-separator composite elements 91 cut therefrom, for example monocells, i.e., to an arrangement downstream of the connecting device 25. Figure 1, for example, shows a further embodiment of an inspection device 10 with cameras 11 arranged on opposite sides of an electrode track 82. This enables inspection of both sides of the electrode track 82, which enables the detection of contamination, defects, foreign bodies, and other anomalies of the planar elements 50, here the electrode track 82, such as chipped edges, holes, cracks, and scratches, on the entire surface of the planar element 50. Of course, an inspection device 10 with cameras 11 arranged on opposite sides of the other electrode track 84 can also be provided.

[0068] An inspection of one or both separator webs 81, 83 is also possible. Figure 1, for example, shows a further embodiment of an inspection device 10 with a camera 11, which is in a measuring relationship to a separator web 81, and an illumination device 70 arranged on the opposite side of the separator web 81. This inspection arrangement 10 therefore measures using the transmitted light method. This enables inspection of the separator web 81 from both sides, which enables the detection of contamination, defects, foreign bodies and other anomalies of the planar elements 50, here the separator web 81, such as chipped edges, holes, cracks and scratches, on the entire surface of the planar element 50. The illumination device 70 is in turn preferably designed to generate light with a wavelength that has a high transmission through the separator web 81 in order to be able to illuminate it as smoothly as possible.Red light, in particular with a wavelength between 600 nm and 1100 nm, preferably between 650 nm and 950 nm, and more preferably between 700 nm and 800 nm, is particularly suitable in this regard. The use of polarized light, optionally with a blocking filter or polarization analyzer, can also be advantageous here. Of course, an inspection device 10 with a camera 11 and an illumination device 70 can be provided additionally or alternatively, which are arranged on opposite sides of the other separator web 83.

[0069] The inspection devices shown in Figure 1 are therefore arranged in the feed section 23 of the machine 13. List of reference symbols

[0070] 10 Inspection device

[0071] 11 Camera

[0072] 12 optical axis

[0073] 13 Machine

[0074] 14 Conveyor device

[0075] 15 Guide band

[0076] 16 funding

[0077] 17 Auxiliary roller

[0078] 18,19 Electrode manufacturing device

[0079] 20 cutting device

[0080] 21 Knife shaft

[0081] 22 cutting drum

[0082] 23 Feed section

[0083] 24 Electrode feed section

[0084] 25 Connecting device

[0085] 26 Pitch change drum

[0086] 27 Transfer device

[0087] 28 transfer drum

[0088] 29 Laminating roller

[0089] 30 single images

[0090] 31 Overall picture

[0091] 32,33 Deflection roller

[0092] 34 Combined Railway

[0093] 35 Preheating device

[0094] 36 upper conveyor

[0095] 40 Conveyor device

[0096] 41 lateral surface

[0097] 43 test track

[0098] 44 Testing device 45 Cutting drum

[0099] 46 knife roller

[0100] 47.49 Rotary conveyor

[0101] 48 stacking station

[0102] 50 flat element

[0103] 51 Contour

[0104] 52 arrester lug

[0105] 53 side edge

[0106] 54 leading edge

[0107] 55 trailing edge

[0108] 56, 57 Parts of an inspection device

[0109] 59, 62 conveyor parts

[0110] 60 electronic evaluation unit

[0111] 63, 64 surfaces

[0112] 70 Lighting equipment

[0113] 71 light beam

[0114] 72 light source

[0115] 73 beam splitters

[0116] 81.83 Separator track

[0117] 82.84 Electrode track

[0118] 91 Composite element

[0119] 92.94 Separators

[0120] 93.95 Electrodes

Claims

Claims:

1. Inspection arrangement for the energy cell manufacturing industry, comprising at least one inspection device (10) for the optical inspection of a planar element (50) conveyed in a machine (13), and with an electronic evaluation unit (60) which is equipped to process data transmitted by the inspection device (10), wherein at least one first part (56) of the inspection device (10) is arranged in a measuring relationship to a first surface of a conveyed planar element (50), characterized in that at least one second part (57) of the inspection device (10) is arranged in a measuring relationship to a second surface of a conveyed planar element (50) opposite the first surface.

2. Inspection arrangement according to claim 1, characterized in that the first part (56) and the second part (57) of the inspection device (10) each comprise a camera (11).

3. Inspection arrangement according to claim 2, wherein the planar elements (50) are conveyed by means of a conveying device (40) comprising a plurality of rotary conveyors (47, 49), characterized in that a first camera (11) is arranged in a measuring relationship to a first rotary conveyor (47) and a second camera (11) is arranged in a measuring relationship to a subsequent second rotary conveyor (49).

4. Inspection arrangement according to claim 3, characterized in that the first rotary conveyor (47) and the second rotary conveyor (49) are arranged successively or by a straight A number of rotary conveyors are arranged separately from one another. Inspection arrangement according to one of claims 2 to 4, characterized in that the cameras (11) are configured for bilateral optical surface inspection of the planar element (50) and the evaluation unit (60) is configured for performing defect detection by means of image processing. Inspection arrangement according to one of claims 2 to 5, wherein the planar element (50) is an electrode-separator composite element (91), characterized in that a first camera (11) is configured for inspecting a first electrode (93) and a second camera (11) is configured for inspecting a second electrode (95) in the electrode-separator composite element (91).Inspection arrangement according to claim 6, characterized in that the electronic evaluation unit (60) is configured to determine the position of the first electrode (93) relative to a separator (92, 94), the position of the second electrode (95) relative to a separator (92, 94), and / or the relative position between the first electrode (93) and the second electrode (93) in the electrode-separator composite element (91). Inspection arrangement according to any one of the preceding claims, characterized in that the inspection device (10) is configured to record a plurality of individual images (30) corresponding to successive conveying positions of the planar element (50), and the data processing device (60) is configured to generate at least one planar image. chiges element (50) comprehensive overall image (31) from the majority of individual images (30) is set up by image processing.

9. Inspection arrangement according to claim 8, characterized in that the dimension of each individual image (30) along the conveying direction is smaller than the dimension of a planar element (50) along the conveying direction.

10. Inspection arrangement according to claim 8 or 9, characterized in that the width b of a single image (30) along a conveying direction of the conveying device designed as a rotary conveyor (47, 49) is a maximum of 2 > / (r 2 - (r- d) 2 ) where r is the radius of the rotary conveyor (47, 49) and d is the depth of field of the inspection device (10).

11. Inspection arrangement according to one of the preceding claims, characterized in that the inspection arrangement has at least one lighting device (70) for illuminating at least one measuring field of the inspection device (10).

12. Inspection arrangement according to claim 11, characterized in that the lighting device (70) is for generating light with a wavelength between 600 nm and 1100 nm, preferably between 650 nm and 950 nm, further preferably between 700 nm and 800 nm.

13. Inspection arrangement according to claim 11 or 12, characterized in that the lighting device (70) is used for the purpose of The inspection arrangement is set up for the generation of polarized light. An inspection arrangement according to claim 2 and any one of claims 11 to 13, characterized in that each camera (11, 11) is assigned at least one separate lighting device (70). An inspection arrangement according to any one of claims 11 to 14, characterized in that the lighting device (70) has a beam axis (71) coaxial with an optical axis (12) of the inspection device (10). An inspection arrangement according to claim 15, characterized in that the lighting device (70) has a beam splitter (73) for deflecting the light beam (71) generated by a light source (72) parallel to the optical axis (12) of the inspection device (10). An inspection arrangement according to any one of claims 11 to 16, characterized in that the lighting device (70) has a beam axis (71) inclined to an optical axis (12) of the inspection device (10).Inspection arrangement according to claim 2 and claim 17, characterized in that a plurality of lighting devices (70) are assigned to the or each camera (11), which illuminate the measuring field of the camera (11) from different sides with beam axes that are oblique to the optical axis (12) of the camera (11) and are alternately non-parallel.

19. Inspection arrangement according to one of the preceding claims, characterized in that the planar element (50) is a material web (81-84).

20. Inspection arrangement according to claim 19, wherein the planar element (50) is a separator web (81, 83), characterized in that the first part (56) of the inspection device (10) is a camera (11) and the second part (57) of the inspection device (10) is a lighting device (70) to enable inspection of the separator web (81, 83) by transmission.

21. Machine (13) of the energy cell manufacturing industry, which is set up for conveying planar elements (50), characterized in that the machine (13) has an inspection arrangement according to one of the preceding claims, which is arranged in a measuring relationship to the conveyed planar elements (50).

22. Machine (13) according to claim 21 , characterized in that the inspection device (10) is arranged downstream of a connecting device (25) of the machine (13).

23. Machine (13) according to claim 21 or 22, characterized in that the inspection device (10) is arranged in a feed section (23) of the machine (13).

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