Device for optical inspection of an arc- or strand-shaped product and method for aligning a camera and / or a lighting device of an optical inspection device

Abstract

Device (101; 101') for optical inspection of an arc-shaped or strand-shaped product (001; 002) - with a transport means (103; 103') designed as a roller (103; 103'), over which the product (001; 002) to be inspected is conveyed or can be conveyed along a transport path in the direction of transport (T), - with a camera which is directed with an inspection line (163) extending over an inspection width perpendicular to the transport direction (T) towards a surface (159) of the roller (103; 103') supporting the product (001; 002) during the inspection, - and with at least one lighting device (106; 106'; 107; 107') by which the surface (159) can be illuminated with a band- or line-like strip of light (164) over at least the inspection width, characterized in that an alignment aid for aligning the inspection line (163) and / or the lighting strip (164) is provided on or in the surface (159) supporting the product (001; 002), which has a marking (161; 162) detectable by the camera (104; 104') and serving to align the inspection line (163) and the lighting strip (164) at at least two points on the surface (159) spaced apart from each other perpendicular to the transport direction (T) and aligned with each other in a direction perpendicular to the transport direction (T), and that the at least two spaced-apart points with marking (161; 162) on or in the surface (159) of the roller (103;103') formed surface (159) and are arranged in the same alignment, parallel to the axis of rotation (D103) of the roller (103; 103').

Description

[0001] The invention relates to a device for the optical inspection of an arc- or strand-shaped product and a method for aligning a camera and / or a lighting device of an optical inspection device according to claim 1 or 9.

[0002] DE 196 04 241 A1 discloses a device for checking the printing quality with a camera directed at a roller shell surface and two lighting devices directed at the shell surface area scanned by the camera.

[0003] DE 10 2016 119 292 A1 relates to a method and a device for testing a functional unit, wherein in one embodiment a line camera is arranged on a web path and a display is located on the opposite side of the path within the detection range of the line camera. To align the line camera, a pattern of marking lines can be displayed on the screen and detected by the line camera.

[0004] The DE 10 2023 117 921 A1 relates to a printing press with multiple printing decks and the precise setting or determination of a print and registration or alignment between all decks participating in a print job on a press.

[0005] German patent DE 10 2019 106 702 A1 discloses a web monitoring system and a method for web monitoring, wherein a camera is directed using transmitted light technology onto a background surface on a rotating drum spaced apart from the web, which travels with the web and serves for calibration purposes. The background surface can be a homogeneous surface or a structure of patterns for color calibration.

[0006] A common practice for aligning a camera inspection line and / or a light strip from a lighting device is to use the leading edge of the product to be inspected as a reference line. However, the accuracy of this alignment depends on the precision achieved during the transport or securing of the product by or on the transport vehicle carrying or conveying it.

[0007] The invention is based on the objective of creating an improved device for the optical inspection of an arc- or strand-shaped product and a method for aligning a camera and / or a lighting device of an optical inspection device.

[0008] The problem is solved according to the invention by the features of claim 1 or 9.

[0009] The advantages achievable with the invention consist in particular in that a camera and / or a light source can be aligned as precisely and reproducibly as possible perpendicular to the transport direction present during operation, in particular perpendicular to the axis of rotation of a roller conveying the products during inspection.

[0010] This eliminates the need for an external reference, such as a conveyed substrate. The reference can be applied with high precision to the conveying medium, especially the roller, for example, under workshop conditions.

[0011] A particularly suitable device for the optical inspection of a bow- or strand-shaped product comprises a transport means, in particular a roller, over or through which the product to be inspected is conveyed or conveyable along a transport path in the direction of transport, a camera, in particular a line camera, which is directed with an inspection line extending over an inspection width transverse to the direction of transport towards a surface of the transport means that supports the product during the inspection, and at least one lighting device by which the surface can be illuminated with a band- or line-like strip of light over at least the inspection width.

[0012] An alignment aid for aligning the inspection line and / or the lighting strip is provided on or in the surface of the transport vehicle supporting the product. This aid has a marking on at least two points on the surface that are spaced apart perpendicular to the direction of transport and aligned with each other in a direction perpendicular to the direction of transport. This marking is detectable by the camera and serves to align the inspection line and / or the lighting strip.

[0013] In this context, a line scan camera is, for example, a camera that scans a two-dimensional object moving relative to the camera, line by line. If desired, the line(s) can be reassembled into a two-dimensional image using appropriate software.

[0014] The term "direction of transport" refers to the direction of transport present at the location under consideration. In the specific case of transport via a roller, this means the direction of transport that is tangential to the circumference at the respective location under consideration, and thus constantly changes as the circumference is moved. In this sense, a line connecting the two aligned points intersects the direction of transport that runs tangentially at the level of the line.

[0015] In an advantageous embodiment, adjustment means are provided – preferably on each side of a double-sided bearing – for alignment purposes. These means allow each end-face bearing point of the line scan camera to be adjusted along a path of movement that lies in a plane parallel to the transport path plane and / or perpendicular to the direction of the optical axis. This allows the line scan camera to be aligned perpendicular to the transport direction and any existing tilt to be corrected. The transport path plane is defined by the plane defined by the vectors of the successive transport directions present at each point during transport over the transport means, representing the same point of a product conveyed over the transport means or the transport path segment without any change in horizontal direction.

[0016] Alternatively or in addition to one or more of the above aspects, in an advantageous embodiment the line camera is fixedly mounted on one end face in the axial direction on the subframe and on the other side with a play in the axial direction allowing a relative movement between the linear camera and the subframe.

[0017] Alternatively or in addition to one or more of the above aspects, in a particularly advantageous embodiment, in addition to the first lighting device – e.g. on the same subframe – a second lighting device, also directed towards the detection area, is provided, wherein the line scan camera is arranged in the transport direction between the first lighting device and the second lighting device, and wherein a central beam of radiation emitted by the first lighting device and a central beam of radiation emitted by the second lighting device have, e.g., a common or at least overlapping illumination strip of impact points extending transversely to the transport direction of the product on a surface of the relevant coating of the product.

[0018] When aligning a camera and / or a lighting device, an inspection line directed by the camera onto the surface of the means of transport and / or a strip of light thrown by the lighting device onto the surface of the means of transport is aligned with points of a single or multi-part marking which are on or in the surface in a direction perpendicular to the direction of transport, aligned with each other and spaced apart from each other.

[0019] Further advantageous embodiments and developments for the above-mentioned device, system and machine can be found individually or in combination in the claims and the following description.

[0020] Exemplary embodiments of the invention are shown in the drawings and are described in more detail below.

[0021] They show: Fig. 1. A schematic diagram of a device for the automatic optical inspection of a product having at least one coating moving along a transport route; Fig. 2. An exemplary image reproduction of an inspected section of the surface, in particular the surface finish, of the product; Fig. 3 a side view of an inspection system designed for double-sided inspection; Fig. 4 a perspective view of an inspection device encompassed by the inspection system and designed in a frame construction in the form of a module with a swiveled inspection head; Fig. 5 a side view of an inspection device encompassed by the inspection system with the inspection unit pivoted; Fig. 6 a partial view from Fig. 6, however with the inspection unit swung away; Fig. 7 a sectional view of the connection of the linear camera to the subframe; Fig. 8 a partial sectional view of an adjusting device for adjusting the line camera in the direction of the optical axis; Fig. 9 a partial sectional view of an adjusting device for adjusting the line camera in a direction perpendicular to the direction of the optical axis; Fig. 10. A schematic diagram to explain the alignment of a camera using markings; Fig. 11. A schematic diagram to illustrate the orientation of a Camera lighting setup based on markings.

[0022] For example, in Fig. The inspection system 100 shown, e.g., inline inspection system 100, comprises at least one first device 101; 102, in particular inspection device 101; 102, for the automatic optical inspection of a strand- or arc-shaped product 001; 002 moving along a transport path, which has a coating 003; 003' on one or both sides of a web- or arc-shaped carrier substrate 006. The product 001; 002 to be inspected can generally be in the form of arc-shaped product sections 001 or preferably in the form of a web-shaped strand of product 002.

[0023] Such an inspection device 101; 102 comprises, for example, in a one- or multi-part frame 111, a camera 104; 104' preferably designed as a line scan camera 104; 104', at least one lighting device 106; 106'; 107; 107' and at least one transport means 103; 103', e.g. in the form of a roller 103; 103', wherein the product 001; 002 is transported along the transport route via the transport means 103; 103'.

[0024] The coating 003; 003' on the product 001; 002 to be inspected can, in principle, be of any type, possibly including a paint or varnish application. However, particularly when providing products 001; 002 which are coated on one or both sides of the web- or sheet-shaped carrier substrate 006 with coatings 003; 003' that are not merely printed with ink, but rather formed by a material layer 003; 003', especially a material layer 003; 003' of a significant thickness of, for example, at least 20 µm, the surface quality and / or completeness of the material layer 003; 003' is often of particular interest for product quality. Such material layers 003; 003' can be, among other things, barrier layers on packaging, protective layers, or other coatings 003; 003' of appropriate thickness, for which continuity and / or uniformity within permissible limits is required.This applies in particular, for example, to the case of product 001; 002 in the form of an electrode string 002 to be provided or of electrode sections 001 with a carrier substrate 006 acting as a current collector 006, which has on one or preferably both sides a material layer 003; 003' formed by an active material layer 003; 003' for a battery electrode, in particular a secondary battery electrode.

[0025] In order to detect defects or flaws in the surface or surface quality of such coatings 003; 003', in particular those formed by material layers 003; 003', and to react accordingly or at least mark them appropriately, a device 101; 102 for inspecting the surface of such a coated product 001; 002 and an inspection system 100 comprising such a device 101; 102 are described in more detail below.

[0026] A coating 003; 003' formed in particular by a material layer 003; 003' forms a relief-like structure with unevenness on the surface of the support substrate 006, whereby tolerance limits or tolerance values ​​are usually specified for these unevennesses and also for a size and number of defects in the coating, which must be adhered to in the manufacturing process of the product 001; 002 and which determine a quality of the coating and thus ultimately also of the entire product 001; 002.

[0027] Not only, but especially in connection with the aforementioned applications, i.e., an inspection device 101; 102 for the automatic optical inspection of a strand- or arc-shaped product 001; 002 with coatings 003; 003' applied to one or both sides of the carrier substrate 006, preferably formed by the aforementioned material layers 003; 003', the inspection device 101; 102, in a preferred embodiment as described below, comprises, in addition to the line camera 104; 104' and the transport means 103; 103', a first and a second illumination device 106; 106'; 107; 107'. The transport means 103; 103' can be driven by a motor or not. It can also, in principle, be a stationary guide element with, for example, a friction-reducing surface, over which the product 001; 002 is being transported or is being transported.The line scan camera 104; 104', the first illumination device 106; 106' and the second illumination device 107; 107 are, as a rule, arranged in a fixed position in the frame of the device 101; 102 with respect to the roller 103; 103', but preferably, in a manner described in more detail below, their position is variable between a working position "A" and a maintenance position "W" relative to the transport means 103; 103'. The transport path or the underlying transport route, along which the product 001; 002 is moved, passes through or crosses an optical detection area of ​​the line scan camera 104; 104', in particular a detection area in the form of an inspection line 163 (see, e.g., ). Fig. 10), wherein the detection area of ​​the line scan camera 104; 104' is illuminated or at least illuminable by both the first illumination device 106; 106' and the preferably also provided second illumination device 107; 107'. The illumination is provided by the respective illumination device 106; 106'; 107; 107' preferably in the form of a band- or line-like illumination strip 164 (see e.g. Fig. 11) By means of automatic optical inspection, production defects and / or defects that have occurred, particularly on a surface of the strand- or arc-shaped product 001; 002, are detected and reported or visualized, preferably during ongoing production, using an image processing method implemented in an electronic, preferably digital, control unit. In the advantageous case of an inline inspection system 100, the transport path of the moving product 001; 002 begins, for example, at its infeed to a machine arrangement that coats a carrier substrate 006 of the product 002 and ends in the transport direction T of the moving product 002 behind its inspection point, e.g., at a location in or on the machine arrangement that collects or at least temporarily stores the inspected product 001; 002.

[0028] In the case of inspecting a carrier substrate 006 coated on both sides with a coating 003; 003', in particular a material layer 003; 003', a first device 101 for inspecting a first side of this product 001; 002 and a second device 102, typically identical in construction to the first device 101, e.g., a second inspection device 102 for inspecting the second side of this product 001; 002, are provided. The first device 101 and the second device 102 together form a double-sided inspection system 100 and are arranged, for example, in a common frame 111 or housing. The inspection system 100 is preferably arranged, or at least can be arranged, as a module in a machine arrangement that coats the carrier substrate 006.

[0029] The coated product 001; 002 is guided or conveyed on its transport path in a flat position on the surface of a conveying means 103; 103'. In a preferred embodiment of the device 101; 102, the product 001; 002 is guided in a flat position on the outer surface of the roller 103; 103' along its circumferential line with a wrap angle α in the range, for example, between 45° and 180°, preferably at least 60°, wherein the wrap angle α defines a contact area K in which, in the present application, the product 001; 002 surrounds the outer surface of the roller 103; 103'. A transport direction T of the product 001; 002 moving in contact with the roller 103; 103' 002 and a direction of rotation of the roller 103; 103' - preferably driven by friction, especially in the case of a strand-shaped product 002 - are specified in the Fig. The direction of travel is indicated by a directional arrow. The product 001; 002 is moved in its transport direction T at a transport speed between 1 m / min and 100 m / min and, in its web-like configuration, with a web tension between 50 N and 600 N. The width b002 of the product 001; 002, extending transversely to the transport direction T, is between 500 mm and 1,200 mm. The roller 103; 103' has a diameter d103 in the range, for example, between 100 mm and 400 mm, and is preferably 200 mm. The runout of the roller 103; 103' has a maximum value of 0.05 mm.

[0030] The line scan camera 104; 104', the first illumination device 106; 106', and the second illumination device 107; 107' provided in a preferred embodiment of the inspection device 101; 102 are arranged in the periphery of the roller 103; 103' in the respective frame 111 of the single- or double-sided inspection system 100, each on the coated side of the product 001; 002, and in their longitudinal extent each transverse to the transport direction T of the product 001; 002, wherein the line scan camera 104; 104' is arranged in the transport direction T between the first illumination device 106; 106' and the second illumination device 107; 107'. A central beam Z106 of the first illumination device 106; 106' emitted radiation and a central ray Z107 of the radiation emitted by the second lighting device 107; 107' have on the relevant coating 003; 003' respectively.Material layer 003; 003' of the product 001; 002 in a circular arc defined by the contact area K of this product 001; 002 with the outer surface of the roller 103; 103' a common impact point AP, wherein this impact point AP forms a line transverse to the transport direction T of the product 001; 002, consisting of several preferably seamlessly connected points, also referred to as illumination strip 164, and is shown in a cross-sectional view of the device 101; 102 as shown in the . Fig. 1 is preferably arranged in the middle of the circular arc formed on the outer surface of the roller 103; 103'. The central beam Z106 of the first lighting device 106; 106' forms an angle β in the range between 10° and 30° with a normal N located at the point of impact AP, i.e., in particular with a radial beam R103 emanating from the center Z103 of the roller 103; 103' and intersecting the point of impact AP, wherein this angle β is preferably 17.5°. The central beam Z107 of the second lighting device 107; 107' forms an angle β in the range between 10° and 30° with respect to the normal N located at the point of impact AP, i.e., in particular with respect to the radial beam R103 emanating from the center Z103 of the roller 103; The radial beam R103 exiting 103' and intersecting the point of impact AP has an angle γ in the range between 45° and 70°, wherein this angle γ is preferably 55°.A central reflection beam Z104, originating from the point of impact AP and directed towards radiation-sensitive elements of the line scan camera 104; 104', runs along an optical axis of the line scan camera 104; 104' and forms an angle θ in the range between 10° and 30° with the radial beam R103, which originates from the center Z103 of the drum 103; 103' and intersects the point of impact AP. This angle θ is preferably 17.5°. Advantageously, this angle θ is equal in magnitude to the angle β formed between the central beam Z106 of the first illumination device 106; 106' and the radial beam R103, which originates from the center Z103 of the drum 103; 103' and intersects the point of impact AP.The angle θ formed between the central reflection beam Z104, emanating from the point of impact AP and directed towards the line scan camera 104; 104', and the radial beam R103, emanating from the center Z103 of the roller 103; 103' and intersecting the point of impact AP, and the angle β formed between the central beam Z106 of the first illumination device 106; 106' and the radial beam R103, emanating from the center Z103 of the roller 103; 103' and intersecting the point of impact AP, are arranged symmetrically to the radial beam R103, emanating from the center Z103 of the roller 103; 103' and intersecting the point of impact AP. The light emitted by the first illumination device 106; 106' and reflected at the point of impact AP onto the coated product 001; 002 reflected radiation thus hits the radiation-sensitive elements of the line camera 104; 104' with its core ray, i.e. its central ray Z106, according to the optical law of reflection "angle of incidence equals angle of reflection".In contrast, the radiation-sensitive elements of the line scan camera 104; 104' detect only diffuse scattered light from the radiation emitted by the second illumination device 107; 107' and reflected at the point of impact AP on the coated product 001; 002, because the arrangement of the second illumination device 107; 107' and the line scan camera 104; 104', and thus the associated beam path, does not conform to the rule formulated by the optical law of reflection, "angle of incidence equals angle of reflection." It is preferably provided that the intensity, i.e., the radiance, of the radiation emitted by the first illumination device 106; 106' is set lower by a control unit controlling the illumination devices 106; 106'; 107; 107' than the radiance of radiation emitted by the second illumination device 107; 107'.

[0031] The first illumination device 106; 106' is arranged at a first peripheral distance a from the point of impact AP of the radiation it emits on the surface of the coated product 001; 002, wherein this first peripheral distance a is in a range between 60 mm and 100 mm and preferably at about 80 mm. The second illumination device 107; 107' is arranged at a second peripheral distance b from the point of impact AP of the radiation it emits on the surface of the coated product 001; 002, wherein this second peripheral distance b is in a range between 60 mm and 100 mm and preferably at about 80 mm. The first peripheral distance a and the second peripheral distance b are preferably of equal magnitude.The radiation-sensing elements of the line scan camera 104; 104' have a third peripheral distance c from the point of impact AP of the radiation emitted by the first illumination device 106; 106' and / or by the second illumination device 107; 107' on the coated product 001; 002 in a range between 20 mm and 40 mm, and preferably in the range between 25 mm and 30 mm. It is therefore advantageous to design the line scan camera 104; 104' as a line scan camera 104; 104' comprising contact image sensors (CIS). In the preferred embodiment, the line scan camera 104; 104' has three rows of CMOS sensors, each extending transversely to the transport direction T of the product 001; 002, with each row being assigned a color filter in one of the colors red, green, or blue.Three consecutive rows of CMOS sensors in the transport direction T of the product 001; 002 thus generate a signal corresponding to the current image acquisition, in particular an RGB signal, wherein this RGB signal is preferably evaluated in the inline image processing system belonging to the machine arrangement coating the carrier substrate 006. The image acquisition and / or image reproduction preferably takes place continuously. The radiation-sensitive elements of the line camera 104; 104', i.e., its typically semiconductor-based photosensors, which are also referred to as pixels, are arranged in a uniform grid both in the transport direction T of the product 001; 002 and transversely thereto in both directions, each with a spacing of 42.3 µm, so that the line camera 104; 104' has an optical resolution of 600 dpi.

[0032] In the preferred embodiment, the radiation from the first lighting device 106; 106' and the radiation from the second lighting device 107; 107' are each designed as white light. Here, white light is defined as polychromatic light with a wavelength, for example, in the range between 360 nm and 760 nm. The first lighting device 106; 106' and the second lighting device 107; 107' each preferably have both a cooling device operated with cooling water and a lens that focuses the respective radiation and homogenizes it over the width b002 of the product 001; 002. The light sources of the first lighting device 106; 106' and the light sources of the second lighting device 107; 107' are preferably each implemented by LEDs.The control unit controlling the first lighting device 106; 106' and the second lighting device 107; 107' operates the respective light sources of both lighting devices 106; 106'; 107; 107' in a sequential manner, such that the light sources of the first lighting device 106; 106' and the light sources of the second lighting device 107; 107' are switched on simultaneously in each exposure period, but remain switched on for different durations. Specifically, the switching-on duration of the light sources of the first lighting device 106; 106' is shorter in each exposure period than that of the light sources of the second lighting device 107; 107'. In the preferred embodiment, the switching-on duration of the light sources of the first lighting device 106; 106' is only one-fifth to one-tenth of the switching-on duration of the light sources of the second lighting device 107; 107'.For example, the on-time of the light sources of the first lighting device 106; 106' is 5 µs and the on-time of the light sources of the second lighting device 107; 107' is 35 µs. However, it can also be provided that the light sources of the first lighting device 106; 106' and the light sources of the second lighting device 107; 107' are operated alternately by the control unit and the respective image lines acquired are processed together in the inline image processing system.

[0033] Fig. Figure 2 shows, in a top view, an exemplary image reproduction on a display device or monitor of a section of the surface of the strand- or arc-shaped product 001; 002 inspected with the proposed inspection system 100. The image acquired by the line-scan camera 104; 104' was evaluated using the inline image processing system. The product 001; 002 is moved along the transport means 103; 103', which is designed, for example, as a roller 103; 103'. A first beam emitted by the first lighting device 106; 106' and a second beam emitted by the second lighting device 107; 107' preferably illuminate together or alternately a line or stripe of light 164 extending transversely to the transport direction T on the surface of this moving product 001; 002.The operationally fixed position of this illuminated line or lighting strip 164 with reference to the circumference of the rotating roller 103; 103' is in the . Fig. Figure 2 is shown as the point of impact AP. The first illumination device 106; 106' provides direct reflective illumination, whereas the second illumination device 107; 107' provides diffuse illumination that generates scattered light. By means of the preferably continuous image acquisition using the line scan camera 104; 104', the surface of the coated product 001; 002 moving in the transport direction T is successively and completely photographically captured.

[0034] In an exemplary case in Fig. In the embodiment shown in Figure 2, which is preferable, for example, in the manufacture of battery electrodes, the coating 003; 003' or material layer 003; 003' on the surface of the support substrate 006 to be inspected is not formed over the entire width b003; b003' extending transversely to the transport direction T, but rather the product 001; 002 has at least one uncoated edge region 108 along its transport direction T. Preferably, an uncoated edge region 108 is formed on both sides of the transport direction T, and in the case of a double-sided coating with such a material layer 003; 003', preferably on both sides of the respective support substrate 006. In an embodiment preferred in the manufacture of battery electrodes, the support substrate 006 forms a current conductor and is preferably made of an electrically conductive, i.e., electrically conductive, material, e.g.made of a metal, especially copper or aluminum or an electrically conductive alloy.

[0035] This results in a device 101; 102 for the automatic optical inspection of a product 001; 002, which is moved along a transport path and has at least one coating 003; 003', in particular a material layer 003; 003', and which comprises at least one transport means 103; 103' for transporting the product 001; 002, as well as a line scan camera 104; 104', a first illumination device 106; 106' and a second illumination device 107; 107', wherein the transport path along which the product 001; 002 is moved crosses a detection area of ​​the line scan camera 104; 104', wherein the line scan camera 104; 104' is located in the transport direction T between the first illumination device 106; 106' and the second illumination device 107; 107' is arranged, wherein the detection range of the line camera 104; 104' is protected by both the first illumination device 106; 106' and the second illumination device 107;107' is illuminated, wherein a central ray Z106 of the radiation emitted by the first illumination device 106; 106' and a central ray Z107 of the radiation emitted by the second illumination device 107; 107' have a common point of impact AP extending transversely to the transport direction T of the product 001; 002 on a surface of the coating 003; 003' of the product 001; 002, wherein the central ray Z106 of the first illumination device 106; 106' has an angle β in the range between 10° and 30° to a normal N standing on the point of impact AP and the central ray Z107 of the second illumination device 107; 107' to the normal N standing on the point of impact AP form an angle γ in the range between 45° and 70°, wherein between a radiation-sensitive element of the line camera 104 emanating from the point of impact AP;An angle θ is formed between the central reflection beam Z104 directed at the first lighting device 106; 106' and the normal N at the point of impact AP, wherein this angle θ and the angle β formed between the central beam Z106 of the first lighting device 106; 106' and the normal N at the point of impact AP are arranged symmetrically to the normal N at the point of impact AP. Preferably, a control unit is provided for controlling the first lighting device 106; 106' and the second lighting device 107; 107', wherein this control unit is configured such that it sets the radiant intensity of the radiation emitted by the first lighting device 106; 106' to be lower than the radiant intensity of the radiation emitted by the second lighting device 107; 107'. The radiation emitted by the first lighting device 106; 106' and the radiation emitted by the second lighting device 107;The radiation emitted by 107' is designed to illuminate, either jointly or alternately, a line extending transversely to the transport direction T on the surface of the product 001; 002, e.g., as an illumination strip 164. In the preferred embodiment, the control unit is configured such that, during ongoing production of the product 001; 002, it performs an image processing method and evaluates a signal from the line camera 104; 104' corresponding to a current image acquisition. The control unit generates a virtual 3D image acquisition by means of the image processing method implemented within it and displays this image acquisition by means of a display device or on a monitor.

[0036] As a result, the first illumination device 106; 106' is arranged and aligned such that, during operation – for example, in a working position “A” as described in more detail below – the central beam Z106 strikes the radiation-sensitive elements of the line camera 104; 104' directly via direct reflection according to the law of reflection with an angle of reflection equal to the angle of incidence, and the second illumination device 107; 107' is arranged and aligned such that, during operation – for example, in working position “A” – no radiation directly reflected from the central beam Z107 according to the law of reflection, but only diffusely reflected radiation from the second illumination device 107; 107' reaches the radiation-sensitive elements of the line camera 104; 104'.

[0037] The inspection system 100, or an inspection device 101; 102 comprised therein, proposed in the preferred embodiment with the first and second lighting devices 106; 106'; 107; 107', enables and thus generates a virtual 3D image capture by means of the image processing method implemented in the control unit. In this process, a relief of the surface of the product 001; 002 is captured and displayed or visualized by means of a display device connected to the control unit, e.g., on a monitor. The shadows cast by irregularities on the surface of the product 001; 002 and / or by defects in the coating 003; 003' – formed in particular by a material layer 003; 003' – create a three-dimensional visual impression in the image reproduction. This impression is intended to highlight undesirable defects 109 on the surface of the product 001; 002 caused by irregularities and / or defects. 002 makes it easily recognizable.The proposed inspection system 100 is therefore ideally suited, in addition to other applications with the aforementioned material layers 003; 003', for quality control of the surface of a product 001; 002 coated, in particular, with an active material layer 003; 003' for a battery electrode, especially a secondary battery electrode, where the manufacturing process requires the most homogeneous possible coating with the material layer 003; 003' without intolerable defects 109 on its surface. Furthermore, the edge profile of the coating 003; 003' can also be monitored with regard to its position and / or continuity in relation to at least one uncoated edge region 108, if present.

[0038] In the following, e.g. in connection with the figures Fig. 3 to Fig. Figure 9 describes a preferred embodiment with advantageous further developments for a single- or double-sided inspection system 100, which comprises a first and optionally a second inspection device 101; 102 arranged in or on a single- or multi-part frame 111, the inspection device having at least one, but preferably as described above, a first and a second illumination device 106; 107; 106'; 107'. An inspection device 101; 102 comprised of the inspection system 100 has a line scan camera 104; 104' as described above, at least one, but preferably a first and a second illumination device 106; 107; 106'; 107', and a transport means 103; 103'.The term "transport means" 103; 103' shall be understood in the broadest sense to mean both a transport means 103; 103' that actively conveys the product 001; 002 by means of its own drive means, and a transport means 103; 103' that merely supports and / or guides the transported product 001; 002, as may be the case, for example, with a roller 103; 103' driven solely by friction with the product 001; 002, or, in the extreme case, even with a stationary guide element with a friction-reducing surface. For the preferred embodiment of the inspection device 101; 102 with two lighting devices 106; 107; 106'; 107', the above description in connection with the first and second lighting devices 106; 107, 106'; 107' shall also apply in whole or in part.

[0039] The product 001; 002 passes through the inspection system 100 along a transport path that leads over at least one contact area K, e.g., a transport path section K, over the at least one transport means 103; 103'. In the configuration of a roller 103; 103', the transport path section K is defined by the contact area K, which is enclosed by the transport path at the relevant wrap angle α. At each point on the transport path, the respective transport direction T is defined by the direction of movement present there, as well as a transverse direction horizontal to the transport direction T in the direction of the width b002 of the product 001; 002, referred to as product width b002. During the passage through the transport path section K leading over the transport means 103; 103', the product 001; 002 and the transport path do not experience any lateral, i.e., vertical, change in direction, thus maintaining the direction of movement along the transport path.The transport directions T of the transport path section K, located centrally with respect to the product width b002, lie in the same plane, in particular perpendicular to the product surface and / or vertically extending, which is also referred to here as a transport path plane. The transport directions T given by the directions of movement of the same point of a product 001; 002 to be conveyed or conveyed along the transport path thus lie, at least in this transport path section K, in such a same plane.

[0040] In an advantageous embodiment of the inspection system 100, in which a double-sided inspection of a double-sided coated product 001; 002 can be carried out in a single operation, the inspection system 100 comprises two inspection devices 101; 102, which are arranged one behind the other on the two opposite sides of the product path, viewed in the transport direction T. The two rollers 103; 103', the associated lighting devices 106; 107; 106'; 107', and the line cameras 104; 104' are supported either in two different or, preferably, by the same one- or multi-part frame 111. In a preferred further development, the inspection system 100 is designed as a modular unit, which can also be integrated as a whole, i.e., without prior disassembly, into the product path of a dedicated inspection machine or a machine for the production and inline inspection of a coated product 001; 002 or product string 002 can be used.

[0041] The frame 111 comprises, for example, end-facing side walls 112 and one or more crossbeams 113 connecting the side walls 112, e.g. at least one crossbeam 113 connecting the side walls 112 in the lower area and designed, for example, in the form of a base plate, as well as possibly further cross connections not shown here.

[0042] A detailed design of the inspection device 101; 102 is set out below using only a first inspection device 101 and is to be applied accordingly to a second inspection device 102 in the case of a double-sided inspection system 100.

[0043] Regardless of whether the inspection system 100 is designed as a single-sided or double-sided system, and regardless of whether each inspection device 101; 102 is provided with one or, preferably, two lighting devices 106; 107; 106'; 107' as described above, in a preferred embodiment the line scan camera 104; 104' and the at least one, preferably the first and the second, lighting device 106; 107; 106'; 107' associated with the same inspection device 101; 102 are mounted on a partial frame 114, which in turn is mounted by means of a bearing that determines the movement, directly or indirectly in or on the frame 111 between a working position "A" and a different maintenance position "W". In particular, the subframe 114 is mounted so that it can be moved along a movement path between the working position “A” and the maintenance position “W”, which runs in or parallel to the aforementioned transport path plane.The bearing is preferably designed such that the subframe 114 is or can be moved along a defined path of movement by a guided translational or rotational movement.

[0044] Preferably, the subframe 114 is pivotably mounted about a pivot axis S extending perpendicular to the transport direction T and / or to the transport path plane and / or parallel to the axis of rotation D103 of the transport means 103; 103' designed as a roller 103; 103' between the working position "A" and the maintenance position "W". This allows cleaning or setup of the line scan camera 104; 104' and / or the associated first and preferably second illumination device 106; 107; 106'; 107' without requiring removal of the relevant component. Furthermore, unlike removal and installation, no readjustment of the illumination devices 106; 107; 106'; 107' and / or the line scan camera 104; 104' is necessary.

[0045] The pivotable bearing of the sub-frame 114 can be mounted on the frame 111 or on a frame construction 118, as described in more detail below, or on its sections 117 or side parts 117, via axles 116 or axle stubs 116 and corresponding bearing bushings on the sub-frame 114, or axle stubs 116 provided at the end face of the sub-frame 114 can be pivotably mounted in bearing bushings of the frame 111 or the frame construction 118 or its side parts 117.

[0046] Preferably, the frame-fixed or rotatable bearing is provided via the axle stubs 116 or the axle 116 in or on shoulders 117 projecting from a flat surface of the side walls 112 towards the transport path. These shoulders, for example, project from the respective side wall 112 as part of it or, preferably, are designed as side parts 117, e.g., side plates 117, attached to the side wall 112. In an advantageous embodiment, the side parts 117 can be parts of a frame structure 118 that directly or indirectly supports the partial frame 114 with the first and / or second lighting device 106; 107; 106'; 107' and the line scan camera 104; 104' and / or is arranged between the side walls 112. Such a frame structure 118 comprises, for example, B. also one or more stiffeners 119 connecting the side parts 117, e.g. crossbeams 119.The frame construction 118 makes it possible to use the frame construction 118 together with the first and / or second lighting device 106; 107; 106'; 107' as well as the line scan camera 104; 104' and, if applicable, the transport device 103; 103', e.g., as a module or as an inspection unit 103; 104, 106, 107, 117, 118, 119 (103', 104', 106', 107', 117, 118, 119) as a whole.

[0047] Preferably, the subframe 114 is pivoted into working position “A” against a frame-fixed stop 121, which acts as an abutment 121, limiting the movement of the subframe 114 in the direction of working position “A” and thereby defining its position in working position “A”. Such a stop 121 can be formed by any frame-fixed stop element that limits the pivoting movement, but here it is preferably formed by a surface 121 of the aforementioned paragraph 117, preferably by a side part 117, which points in the direction of the pivotable subframe 114 and forms an abutment 121 for the subframe 114.

[0048] In an advantageous embodiment, a fitting element 122, e.g. a dowel pin 122, is provided in the subframe 114 or in the side part 117, which acts between the pivotable subframe 114, in particular a side part 126 of the subframe 114, and the abutment 121 limiting the pivoting movement, and which engages in a complementary recess 123 in the other part, i.e. in the first case in the side part 126 or in the second case in the subframe 114, and defines at least one axial position of the subframe 114 in working position “A”. Additionally, a screw connection 124 can be provided between the sub-frame 114 and a frame-fixed component, in particular between the sub-frame 114 and the shoulder 117 or side part 117 serving as a support 121 for the sub-frame 114, by which the sub-frame 114 can be fixed in working position “A”, and which can be released for pivoting.

[0049] In the illustrated and advantageous embodiment, the pivot axis S or axis 116 is arranged off-center with respect to the extension of the subframe 114 in the transport direction T, i.e., with respect to the extension towards the adjacent line scan cameras 104; 104' and the first and / or second illumination units 106; 107; 106'; 107', particularly in the region of one end of the respective side panel 126. In a variant in which, for example, lower torques result when pivoting the subframe 114, the pivot axis S or axis 116 can also be arranged approximately centrally, i.e., lying in the plane of the optical axis of the line scan camera 104; 104', or at most a few mm away from it, e.g., at most ± 50 mm.

[0050] The roller 103; 103', which also serves as a guide for the product 001; 002 during inspection, can be rotatably mounted on the frame 111 of the inspection system 100 by means of a roller journal 127 directly on the side wall 112 or indirectly in the aforementioned side plate 117. In the latter case, an inspection unit 103; 104, 106, 107, 117, 118, 119 (103', 104', 106', 107'; 117', 118', 119') designed as an inspection module can include the roller 103; 103' in addition to the first and / or second illumination device 106; 107; 106'; 107' and the line scan camera 104; 104'.

[0051] As a result, the subframe 114, and thus the first and / or second lighting device 106; 107; 106'; 107' supported by it, as well as the associated line camera 104; 104', can be repositioned relative to the roller 103; 103' from a working position "A" to a maintenance position "W", in particular pivoting, wherein, for example, at least one correct axial position of the subframe 114 in working position "A" is defined by a fitting element 122 and / or the subframe 114 can be fixed in working position "A" by a screw connection 124. In the above case of an embodiment of the inspection unit 103; 104, 106, 107, 117, 118, 119 (103', 104', 106', 107'; 117, 118', 119') as an inspection module, this can be inserted as a whole into the frame 111 while maintaining the relative positions and distances between the relevant components and can be replaced if necessary.

[0052] In an advantageous embodiment, the first and / or the second lighting device 106; 107; 106'; 107' in the subframe 114 is adjustable with respect to a direction of radiation about a rotational axis perpendicular to the transport direction T. This allows the angle α at which the central beam Z106; Z107 of the respective lighting device 106; 107; 106'; 107 strikes the roller 103; 103' in operating position "A", and the point of impact on the circumference, to be varied. This is achieved, for example, by mounting the respective lighting device 106; 107; 106'; 107' on axles 128; 129, in particular axle stubs 128; 129, at both ends. 129, is mounted, which are rotatably mounted in the side parts 126 of the subframe 114 (see e.g. double arrows in Fig. 5) To fix the lighting device 106; 107; 106'; 107 in a specific position, a releasable clamping device 131; 132 is provided, for example.

[0053] In a particularly advantageous embodiment, the line camera 104; 104' is not fixedly attached to the subframe 114, but is adjustable via at least one adjusting device 134, 136, 137, 138, 139, 141, 142, 143 with respect to the distance to the associated roller 103; 103', in particular in the direction R F The optical axis, or in the direction of focus, is adjustable. This allows the focus to be set directly on the surface of the product 001; 002 to be inspected, thus obtaining a sharp image. The [missing information] along this direction R F The direction of movement coincides – with correct positioning and alignment – ​​for example with the direction of the reflection beam Z104 in Fig. 1 together. This allows the focus to be adjusted on the surface of the roller 103; 103' without changing the overall arrangement, i.e. the position of the first and / or second illumination device 106; 107; 106'; 107'.

[0054] For the aforementioned adjustment of the line scan camera 104; 104', it is preferably supported on at least one bracket, preferably on two end-face brackets 133, which in turn are mounted on at least one, e.g., centrally located, but preferably on two end-face adjusting devices 134, 136, 137, 138, 139, 141, 142, 143 for adjusting the line scan camera 104; 104' in the direction of the optical axis, hereinafter also referred to as first adjusting devices 134, 136, 137, 138, 139, 141, 142, 143 for better distinction. For this purpose, the brackets 133 are each attached to at least one slide 134, which can perform a guided movement along a single or multiple linear guide 136 in a direction that is either the aforementioned or parallel to it. For example, the slide 134 has at least one bore which is located in the aboveextending the direction of movement and forming the linear guide 136, encompasses the round rod 136 and is movable on it in its longitudinal direction (see e.g. . Fig. 8) Preferably, several such guide pairs, e.g., two, consisting of a round rod 136 and a bore, are provided. The slide 134, and thus the mount 133 including any line scan camera 104; 104' attached thereto, can be adjusted by an adjusting mechanism 137, which in particular comprises a gear mechanism. In an advantageous embodiment, a threaded drive 138, 139 is provided as the gear mechanism, for example, a screw 138, e.g., an adjusting screw 138, whose threaded shank extends in the direction of movement and engages in a thread 139 provided on or in the slide 134. The at least one linear guide 136 and the adjusting screw 138 can be supported by a frame 141, e.g., in the form of a frame or a housing, in or on which the at least one slide 134 is movable along the guide.The adjusting screw 138 may, for example, have a screw head 142 at its free end that can be operated manually or by a tool and / or a scale that interacts with a mark on the frame 141 (see e.g. . Fig. 9) or vice versa. In an advantageous embodiment, the transmission is spring-loaded against any backlash that may be present. In the present case of a threaded drive 138, 139, for example, a spring 143 surrounding the linear guide, e.g. a compression spring 143, is provided, which repels itself on one side from the frame 141 and presses with its other end against the slide 134 in the direction of the screw head 142.

[0055] The positioning device 134, 136, 137, 138, 139, 141, 142, 143, which enables the positioning of the line camera 104; 104' in the focus direction, or its frame 141, can in principle be fixedly arranged on the pivotable partial frame 114 or on its side part 117.

[0056] Basically independent of the positionability in the direction of R F of the optical axis, preferably in addition to this, adjusting devices 144, 146, 147, 148, 149, 151, 152, 153 are provided on each end face, by which a respective end of the line camera 104; 104' can be adjusted in a direction perpendicular to the direction R Fthe optical axis runs and is at least nearly, i.e., with a deviation of a maximum of 2°, perpendicular to the axis of rotation D103 of the roller 103; 103'. For the sake of simplicity, these adjusting devices 144, 146, 147, 148, 149, 151, 152, 153 are hereinafter also referred to as second adjusting devices 144, 146, 147, 148, 149, 151, 152, 153 or, for better differentiation, as adjusting means 144, 146, 147, 148, 149, 151, 152, 153. In the following, these positioning devices 144, 146, 147, 148, 149, 151, 152, 153 are also referred to as positioning devices 144, 146, 147, 148, 149, 151, 152, 153 serving an alignment parallel to the axis or perpendicular to the substrate side edge and / or transport direction.

[0057] For this purpose, the respective adjusting means 144, 146, 147, 148, 149, 151, 152, 153 has at least one direction R perpendicular to, for example, the optical axis and the rotation axis D103 of the roller 103. ⊥linear guide 146, e.g. in the form of a round bar 146, on which a slide 144 runs linearly along a path perpendicular to the direction R F the optical axis and direction R running perpendicular to the axis of rotation D103 ⊥ is movable (see e.g. Fig. 9) The carriage 144 thus acts as a bearing point 144 for the line camera 104; 104', which is adjustable along a movement path that lies in a plane parallel to the transport path plane and perpendicular to the direction R F the optical axis. The adjusting means 144, 146, 147, 148, 149, 151, 152, 153 provided on the two end faces of the line camera 104; 104' for positioning perpendicular to the direction R FThe optical axis can be adjusted independently of one another, thus enabling the correction of any tilting of the line scan camera 104; 104'. The carriage 144 – and with it the line scan camera 104; 104' attached directly or indirectly to it – can be adjusted by an adjusting mechanism 147, which in particular includes a gear. In an advantageous embodiment, a threaded drive 148, 149 is provided as the gear, for example a screw 148, e.g., an adjusting screw 148, whose threaded shank extends, for example, in the direction R perpendicular to the optical axis and the roller axis. ⊥The linear guide 146 extends and engages in a thread 149 provided on or in the slide 144. The at least one linear guide 146 is supported by a frame 151, e.g., in the form of a frame or a housing, in or on which the at least one slide 144 is movable along the linear guide 146. In an advantageous embodiment, the transmission is spring-loaded against any backlash that may be present. The adjusting screw 148, which engages in the thread 149, is supported, for example, by its screw head 152 on one side of the slide 146 against the frame 151, while on the opposite side of the slide 144, a spring 153 surrounding the linear guide 146, e.g., a compression spring 153, is supported against the opposite side of the frame 151 and biases the slide 146 in the direction of the adjusting screw 148. The screw head 152 of the adjusting screw 148 can be accessed, for example, through a recess in the frame 151 using a suitable tool, e.g.accessible with an Allen key.

[0058] In a particularly advantageous embodiment, each end face is equipped with a first adjusting device 134, 136, 137, 138, 139, 141, 142, 143 for adjusting the line camera 104; 104' in the direction R. F the optical axis, as well as a second adjusting device 144, 146, 147, 148, 149, 151, 152, 153 for adjusting in a direction perpendicular to this R ⊥ The frame 141 of the first actuating device 134, 136, 137, 138, 139, 141, 142, 143 is preferably arranged on the carriage 144 of the second actuating device 144, 146, 147, 148, 149, 151, 152, 153, or, if applicable, the frame 151 of the second actuating device 144, 146, 147, 148, 149, 151, 152, 153 is arranged on the carriage 141 of the first actuating device 134, 136, 137, 138, 139, 141, 142, 143.

[0059] Since positioning by the front-facing second positioning devices 144, 146, 147, 148, 149, 151, 152, 153 can cause a slight rotational movement of the arrangement, i.e. a non-linear movement of the respective line camera end, this end does not move exactly, but only "almost" linearly, as indicated above.To prevent torsional stress in the direct or indirect connections between the second actuating device 144, 146, 147, 148, 149, 151, 152, 153 and the line camera 104; 104', the connection of the carriage 144 of the second actuating device 144, 146, 147, 148, 149, 151, 152, 153 with the side bracket 133 of the line camera 104; 104' or - in the case of an intermediate first actuating device 134, 136, 137, 138, 139, 141, 142, 143 - with the frame 141 of the first actuating device 134, 136, 137, 138, 139, 141, 142, 143 realized by a screw connection 154, which simultaneously creates a pivot point for relative rotation as a degree of freedom. Preferably, a connection via a floating bearing mentioned below is provided on one of the end faces.

[0060] In an advantageous embodiment of the inspection device 101; 102, which, for example, prevents thermal stresses resulting from heating of the line camera 104; 104' and / or from mechanical stresses resulting from the alignment of the line camera 104; 104', the axial connection of the line camera 104; 104' to the subframe 114 or its side panel 126 is not rigidly formed on both end faces, but rather on one of the two sides as a so-called floating bearing, i.e., with axial play Δx. This can be provided in principle in the area of ​​various connections between components located between the line camera 104; 104' and the side panel 126.In an advantageous embodiment, illustrated here by way of example, the axial play Δx is already eliminated in the connection between the side part 126 of the pivotable partial frame 114 and the frame 141; 151 of the next – first or second – actuating device 134, 136, 137, 138, 139, 141, 142, 143; 144, 146, 147, 148, 149, 151, 152, 153 in the direction of the line camera 104; 104', preferably the frame 151 of the second actuating device 144, 146, 147, 148, 149, 151, 152, 153 acting perpendicular to the optical axis. For example,a blind hole in the frame 141; 151 of the respective adjusting device 134, 136, 137, 138, 139, 141, 142, 143; 144, 146, 147, 148, 149, 151, 152, 153, which has a larger diameter than a threaded bore 158, dimensioned in length such that a stronger section 156, designed in the manner of a bolt, of a screw 157, which is guided from the outside through a bore in the side part 126 and tightened in the threaded bore 158, abuts with an annular end face against the annular step of the blind hole before the frame 141; 151 of the respective adjusting device 134, 136, 137, 138, 139, 141, 142, 143; 144, 146, 147, 148, 149, 151, 152, 153 against the inside of the side part 126.

[0061] Basically, considered on its own and regardless of whether the inspection device 101; 102 has one or two lighting devices 106; 106'; 107; 107' arranged as above, for example, and / or whether the product 001; 002 has a coating 003 formed by a paint, varnish or other material application or film;003' and / or an embodiment with a movable, in particular pivotable, partial frame 114 and / or an embodiment with an axial play in the bearing arrangement and / or an embodiment with an adjusting device 134, 136, 137, 138, 139, 141, 142, 143 serving for adjustment along the optical axis and / or an embodiment with an adjusting device 144, 146, 147, 148, 149, 151, 152, 153 serving for alignment parallel to the axis or perpendicular to the transport direction, but particularly advantageous in combination with one or more of the aforementioned and above-described embodiments, in particular at least in combination with the adjusting devices 144, 146, 147, 148, 149, 151, 152 serving for alignment parallel to the axis or perpendicular to the transport direction T, 153, is on the means of transport 103; 103', in particular on the means of transport 103 designed as a roller 103; 103';103', an alignment aid is provided by which an axially parallel and / or perpendicular alignment to the present transport direction T of an inspection line 163 of the camera 104; 104', in particular a line scan camera 104; 104', and / or of an illumination strip 164, also referred to above as an illuminated "line", of one or more illumination devices 106; 106'; 107; 107', in particular those producing band or line illumination, can be checked and by means of which any deviation that may be present can be corrected. The illumination strip 164 is projected by the illumination device 106; 106'; 107; 107' onto the surface 159 via a beam path 167, e.g. a so-called light cone 167, the camera 104; 104' scans the image present along the inspection line 163 via a so-called sight cone 166.;

[0062] The alignment aid has at least two points spaced apart perpendicular to the transport direction T and aligned with each other in a direction perpendicular to the transport direction T, or a marking 161; 162 detectable by at least one camera 104; 104' on the surface 159 of the transport means 103; 103' on which the product 001; 002 rests during inspection on the side opposite the camera 104; 104'. These two points can be identical markings 161, 162 extending continuously over a distance corresponding to the distance between these points ("one-piece"), or, in a preferred embodiment, two marking sections 161; 162 spaced apart but aligned with each other in a direction perpendicular to the transport direction T ("multi-piece"). The two markings 161; 162 can also be point-like, i.e., with a substantially identical, but small extent – ​​e.g.,B. of at most 3 mm, in particular at most 1 mm - in the transport direction T and transversely thereto, shall be formed.

[0063] Regardless of whether it is designed as a continuous or multi-part marking 161, 162; 161; 162, this single or multi-part marking 161, 162; 161; 162 should comprise two points spaced apart and aligned with each other in the manner described above, which have a distance between them of at least one quarter, but in particular at least one half, of the maximum product width b002 of the product 001; 002 to be inspected by the inspection device 101; 102 and / or at least one quarter, in particular at least one half, of a maximum working width of the inspection device 101; 102, i.e. the maximum width to be inspected by the inspection device 101; 102 or the width of the inspection line 163 viewed by the camera 104; 104', which in the case of a line scan camera 104; 104 corresponds, for example, to the distance between the line ends.

[0064] Preferably, the single or multi-part marking 161, 162 extends on both sides such that it has at least one aligned section of a marking 161; 162 in each area of ​​the side edges of a maximum product width b002 and / or in the area of ​​the lateral boundary of the maximum working width. These sections can preferably be encompassed by linear marking sections 161; 162 that run perpendicular to the transport direction T and are aligned, spaced apart from each other transversely to the transport direction T, and extend, for example, to or beyond the boundary of the lateral working width. Alternatively, they can be defined by a continuous marking line 161, 162 that extends from the center to both sides to or beyond the boundary of the working width.The existence of such widely spaced markings 161; 162 ensures the highest accuracy and / or allows operators to easily perform a visual check of the position of a lighting strip 164 from the side. Preferably, the continuous or segmentally formed, single- or multi-part marking 161, 162; 161; 162 overlaps the boundary line on the surface 159 of the transport means 103; 103', which is defined by the maximum product width b002 or working width.

[0065] In a preferred embodiment of the transport means 103; 103' designed as a roller 103; 103', the one- or multi-part marking 161, 162; 161; 162 is provided on its circumference, i.e., on or in its surface 159, in particular its outer surface 159. In the case of a continuous marking 161, 162, its longitudinal extent runs parallel to the axis of rotation D103 of the roller 103; 103'. In the case of a multi-part marking 161, 162; 161; 162, for example, two linear marking sections 161; 162 each run parallel to the axis of rotation D103 of the roller 103; 103' and are aligned with each other. The position of the at least two locations with markings 161, 162; 161; 162 and / or the position and extent of the single or multi-part marking 161, 162; 161; 162, the above applies.

[0066] A single or multi-part marking 161, 162; 161; 162, comprising the aforementioned locations, can be applied, for example, by applying material to the upper or lateral surface 159, e.g., by printing, or preferably by being indented into the surface 159, e.g., by engraving. A continuous marking 161, 162 can be applied or indented, or two aligned markings 161; 162 can be applied or indented at a distance from each other.

[0067] In an advantageous embodiment, the single or multi-part markings 161, 162; 161; 162, used to check and / or correct the axially parallel and / or perpendicular alignment of the inspection line 163 and / or the illumination strip 164, should, at least in an area encompassing the spaced-apart points to be used, have a maximum extent of 3 mm, and in particular 1 mm, along the transport path in the transport direction T of the product 001; 002, and especially in the circumferential direction of the roller 103; 103'. Greater thicknesses in the circumferential or transport direction T may otherwise compromise the accuracy of the adjustment.

[0068] In preferred and e.g. in Fig. 10 and Fig.In the embodiment shown in Figure 11, line-like marking sections 162; 162 are provided in the two lateral edge areas of the working width in or on the surface 159, in particular in or on the cylindrical surface 159, which are aligned with each other and, in the preferred case of a roller 103; 103', run parallel to the axis of rotation D103 of the roller 103; 103'.

[0069] In a further development process, a lateral position of the one- or multi-part marking 161, 162; 161; 162 or of an end of such a one- or multi-part marking 161, 162; 161; 162 in the operation of the inspection device 101; 102 can serve as a reference for the lateral position of the product 001; 002 to be inspected or the coating 003; 003' to be inspected on it, by, for example, determining a distance between the position of the one- or multi-part marking 161, 162; 161; 162 or its end to be used for this purpose and the product edge or a coating edge based on the image obtained by the camera 104; 104' and, if necessary, comparing it with a desired position.

[0070] In an advantageous embodiment of the inspection device 101; 102, however, a further marking 168, different from the aforementioned one- or multi-part marking 161, 162; 161; 162, can be provided on or in the surface 159. This further marking 168 serves as a reference for the lateral position of the product 001; 002 to be inspected or of a coating 003; 003' applied to the product 001; 002. Such a further marking 168 can be designed as a marking line 168 extending at least over a section in the transport direction T, in particular in the circumferential direction of the roller 103, 103'. It can, for example, be designed as a marking line extending in the transport direction T, in particular in the circumferential direction of the roller 103; 103' continuous marking line 168 over the circumference or a circumferential section or a plurality of marking line sections running in the circumferential direction and aligned with each other in the circumferential direction.

[0071] To align the camera 104; 104' and / or a lighting device 106; 106'; 107; 107' of the optical inspection device 101; 102, the inspection line 163 directed by the camera 104; 104' onto the surface 159 of the transport means 103; 103', in particular the roller 103; 103', is aligned at the positions of a one- or multi-part marking 161, 162; 161; 162, which is located on or in the surface 159 of the transport means 103; 102 - e.g. during setup of the device 101; 102 outside of inspection operation, i.e. without a product 001; 002 resting on the relevant area of ​​the surface. 103' are aligned and spaced apart from each other in a direction perpendicular to the transport direction T.

[0072] Alternatively or additionally, to align the lighting device 106; 106'; 107; 107' of the optical inspection device 101; 102 - e.g. during the above setup - the illumination strip 164 thrown by the lighting device 106; 106'; 107; 107' onto the surface 159 of the means of transport 103; 103' is aligned at points of a one- or multi-part marking 161, 162; 161; 162 which are located on or in the surface 159 of the means of transport 103; 103' in a direction perpendicular to the direction of transport T, aligned with each other and spaced apart.

[0073] In the case of aligning the camera 104; 104' and the lighting device(s) 106; 106'; 107; 107', preferably the camera 104; 104' can be aligned first, followed by the lighting device(s) 106; 106'; 107; 107', or vice versa. The former ensures that the camera 104; 104' is already correctly aligned and does not provide a distorted image for the lighting strip(s) 164 due to misalignment. The alignment of the camera 104; 104' can, in principle, be achieved by any suitable mechanism, but is preferably carried out by the aforementioned adjusting devices 144, 146, 147, 148, 149, 151, 152, 153, which serve for alignment parallel to the axis or perpendicular to the transport direction T.

[0074] When aligning the camera 104; 104', a display device, e.g., a screen displaying the image scanned along the inspection line 163, is used to check whether the spaced-apart and aligned points of the single or multi-part marking 161, 162; 161; 162, preferably located in the area of ​​the line ends or the working width, are visible simultaneously. This is done in particular with the position of the transport means 103; 103', especially a rotating position of the roller 103; 103', in which the marking 161; 162 should be simultaneously visible at the at least two aligned points across the inspection line 163. If this is not the case, the position of the camera 104; 104' must be corrected according to the deviation.

[0075] The camera 104; 104' is, for example, aligned such that, in a corresponding position of the transport means 103; 103' or the roller 103; 103', the aligned and spaced-apart points of the one- or multi-part marking 161, 162; 161; 162 are visible simultaneously and aligned on the same line in the image taken by the camera 104; 104'.

[0076] When aligning the lighting device or each lighting device 106; 106'; 107; 107', it is adjusted such that, in a corresponding position and / or orientation of the transport means 103; 103', in which, for example, at least partial overlap between the lighting strip 164 and the single or multi-part marking 161, 162; 161; 162 is to be expected, the lighting strip 164 in question hits or at least aligns with the aligned points of the single or multi-part marking 161, 162; 161; 162. This can be done visually by the operating personnel or, preferably, via the image captured by the camera 104; 104' and displayed on the screen.

[0077] The design of the inspection device 101; 102 with the alignment of the camera 004; 004 and / or the lighting device(s) 106; 106'; 107; 107' and optionally further one- or multi-part marking 161, 162; 161; 162; 168 and the associated alignment procedure is advantageous also in conjunction with coatings 003; 003' designed as material layers 003; 003' of significant thickness, but is not limited to such applications, but is particularly applicable to applications in which printing inks, varnishes or other types of materials or layers are applied to a substrate 006 as a coating 003; 003' and are to be optically inspected.

[0078] In a preferred embodiment, an inspection system 100 is provided in the substrate path of a machine arrangement for the production of a product 001; 002, with a material layer 003; 003' applied to a carrier substrate 006 – preferably on both sides. In a machine arrangement comprising an inspection system 100, a device for marking defects and / or flaws can be located downstream of the inspection system 100 in the product path. This device can be, for example, a printing device, e.g., an inkjet printhead, that applies a corresponding marking, or an injection device, the latter being able to insert or apply a marking element, e.g., a marking flag or a marking label, onto the strand- or arc-shaped product 001.For example, such a device receives a corresponding error signal from inspection system 100 if there is a deviation from the required surface and / or web edge quality.

[0079] As mentioned above, the single- or double-sided inspection system 100 can also be part of a stand-alone machine for inspecting and, if necessary, marking defective areas in the product 001; 002, which includes, for example, a substrate feed, e.g., a roll unwinder, the inspection system 100, preferably a device downstream in the product strand path for marking defects and / or flaws, and an output-side product intake through which the product can be rewound into product packages, e.g., into product rolls, or bundled into stacks after cross-cutting.

[0080] The inspection device 101; 102 or the inspection system 100, as described above, comprising in particular the two lighting devices 106; 106'; 107; 107', is particularly advantageous for those applications in which a web- or arc-shaped support substrate 006 – for example, thin, e.g., at most 250 µm thick and / or possibly non-torsionally rigid – has a material layer 003; 003' on one or both sides – e.g., of a significant thickness of at least 20 µm, for example, a thickness in the range of e.g., between 20 µm and 250 µm. For support substrates 006 optionally formed from paper or cardboard, the thickness can also be greater. Preferably, these are applications or products to be inspected 001; 002, in which the coating 003; 003' applied to the carrier substrate 006 is significantly different and / or thicker than a printing fluid applied using printing technology, such as e.g.a printing ink or a printing ink and / or in which a continuous coating 003; 003' is provided over the entire width b003; b003' of the coating 003; 003', for which, for example, as explained above, continuity and / or a thickness that is as uniform as possible is required. In a particularly advantageous embodiment, the inspection device 101; 102 or the inspection system 100 relates to the inspection of the surface of an electrode section 001 or electrode strand 002 comprising an active material layer 003; 003' on one or both sides for a secondary battery, also referred to as an accumulator, or for the manufacture of one such battery.

[0081] A coating 003; 003' formed by a material layer 003; 003' in the above sense can, for example, be a barrier or protective layer applied over a large area and continuously across the width b003; b003' with a corresponding thickness, e.g. in the form of a large continuous lacquer or plastic layer, from which a defect-free and / or uniform surface quality is required.

[0082] For the aforementioned advantageous case of the design of the inspection device 101; 102 or the inspection system 100 for inspecting the surface of an electrode section 001 or electrode string 002 comprising an active material layer 003; 003' on one or both sides for a secondary battery or for the manufacture of such a battery, the active material layer 003; 003' to be inspected can, in principle, be designed at the inspection site as an active material layer 003; 003' that is still moist, i.e., initially applied moist, e.g., in the form of a slurry, i.e., in particular a viscous suspension or paste, and still containing solvent, which is then dried, for example, in a subsequent process step, e.g., inline by a dryer.In another advantageous embodiment and / or at another point in the process, the active material layer 003; 003' can be present at the inspection site as a dry material layer 003; 003', wherein, in a first variant, the active material layer 003; 003' is formed, for example, by an active material layer 003 that is initially applied to the support substrate 006 in a moist state, e.g., as a slurry, and subsequently dried, or, in an advantageous second variant, the coating 003; 003' formed by an active material layer 003 is formed by a dry film, i.e., a coating 003; 003' that is already present as a dry film applied to the support substrate 006. In the context of this application, a dry film is to be understood as a coating that is applied to the support substrate 006 in a solvent-free state.

[0083] An active material layer 003; 003' for a battery, in particular a secondary battery, and / or an effective material layer 003; 003' comprises, for example, at least one active material for a secondary battery, i.e., a chemical substance for energy storage, e.g., a lithium metal oxide, and optionally a binder and / or – e.g., in the case of wet application – a solvent. The support substrate 006 is, for example, designed as a metal foil or as a metal mesh and has, for example, a material thickness of at least 4 µm, e.g., in the range between 4 µm and 20 µm. The thickness of an applied active material layer 003; 003' is, for example, at least 20 µm and is, for example, in the range between 20 µm and 250 µm. Reference symbol list 001 Product, product section, electrode section 002 Product, product strand, electrode strand 003 Coating, material layer, active material layer 003' Coating, material layer, active material layer 006 Carrier substrate, current collector 100 inspection system, inline inspection system 101 Device, first, inspection device 102 Device, second, inspection device 103 Means of transport, roller 103' Transport vehicle, roller 104 camera, line scan camera 104' camera, line scan camera 105 - 106 Lighting equipment, first 106' Lighting equipment, first 107 Lighting device, second 107' Lighting device, second 108 Edge area 109 Fault point 110 - 111 frame 112 Side wall 113 Traverse 114 subframe 115 - 116 axle, axle stub 117 paragraph, side panel, side plate 118 Frame construction 119 Stiffening, crossbeam 120 - 121 Stop, abutment, surface 122 Dowel pin, locating pin 123 In-depth study 124 Screw connection 125 - 126 side panel 127 roller journals 128 axle, axle stub 129 axle, axle stub 130 - 131 Clamping device 132 Clamping device 133 bracket 134 sleds 135 - 136 Linear guide, round bar 137 Adjustment mechanism 138 Screw, adjusting screw 139 threads 140 - 141 frame 142 screw head 143 Spring, compression spring 144 sleds, storage location 145 - 146 Linear guide, round bar 147 Adjustment mechanism 148 Screw, adjusting screw 149 threads 150 - 151 frame 152 screw head 153 Spring, compression spring 154 Screw connection 155 - Section 156 157 screw 158 threaded hole 159 Surface area, lateral surface area 160 - 161 Marking, Marking Section 162 Marking, Marking Section 163 Inspection line 164 lighting strips 165 - 166 cones of vision 167 Beam path, light cone 168 Marking, marking line “A” working position "W" Maintenance location S swivel axis b002 Width, product width (002) b003 Width (003; 003') b003' Width (003; 003') d103 diameter D103 axis of rotation a distance, first (106; 106') b Distance, second (107; 107') c distance, third (104; 104') AP impact point K Contact area, transport path section N Normal R F Direction R⊥ direction T Transport direction R103 Radial beam Z103 Center (103; 103') Z104 Reflection beam Z106 Central beam (106; 106') Z107 Central beam (107; 107') α Wrap angle β angle γ angle θ angle Δx play, axial

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