Inspection apparatus for the image-sensor-based inspection of an object

Abstract

The invention relates to an inspection apparatus for the image-sensor-based inspection of an object (3), the inspection apparatus (1) comprising: a transport device for transporting a physical object (3) to be inspected along a transport path; an image sensor system (6) having at least one image sensor (35) for scanning at least part of the object (3), by image sensor, along a viewing direction (18) while the object (3) is continuously moved by the transport device along the transport path relative to the image sensor system (6); and an illumination device for illuminating a surface to be inspected, of the object (3), in a wavelength range which can be captured by the image sensor system (6), so that the image sensor system (6) can at least partly capture, by image sensor, the surface in a surface region illuminated in this way. The image sensor system (6) has a number N, where N ≥ 1, of digital line scan cameras (7) which are individually or cumulatively in the form of a contact image sensor, CIS, and which each have a plurality of camera pixels (27) arranged in a line, each camera pixel having a lens (28), and the lines of the N line scan cameras (7) each extend transversely to the transport path. The illumination device is configured such that, in order to illuminate the surface to be inspected, of the object (3), the illumination device generates light and directs said light along a beam path (24), the direction of which coincides with the viewing direction (18) or differs therefrom by at most 30°.

Description

[0001] 120637P898PC

[0002] - 1 -

[0003] Inspection device for image sensor-based inspection of an object

[0004] The present invention relates to an inspection device for image sensor-based inspection of an object and a method for image sensor-based inspection of a physical object.

[0005] When manufacturing or using a wide variety of physical objects—that is, objects that occupy space and mass, especially intermediate or end products of industrial production processes—ensuring high-quality objects is crucial. Quality requirements can relate, in particular, to the integrity or purity of one or more surfaces of the object. Electrodes for galvanic cells, such as lithium-ion batteries, are an example of such objects. These are used in a multitude of electronic devices, for instance, in electromobility to power vehicles or for the intermediate storage of electrical energy in stationary systems. However, if defective electrodes are subsequently laminated or stacked, short circuits can occur. Therefore, quality assurance testing is necessary before their use.

[0006] Before testing, the electrodes are shaped by stamping or laser cutting. However, stamping or laser cutting can cause coating particles to break off from the electrode surface, and these particles must be detected. Other damage caused by stamping or laser cutting must also be identified. In many of these cases, black carbon particles on a black surface must be detected, meaning the test often has to be performed under very low-contrast lighting conditions.

[0007] In known solutions, as part of quality assurance, finished batteries, which may contain one or more galvanic cells, are tested at the factory for electrical short circuits. This test is performed while stationary, i.e., when the battery is at rest relative to the test fixture used for the test. 120637P898PC

[0008] - 2 -

[0009] DE 102022113313 A1, on the other hand, describes a device for sensor-based inspection of a physical object, in particular a plate-shaped or strip-shaped object, in which a transport device is provided for transporting a physical object to be inspected along a transport path and an image sensor captures the object image-sensorically while it is continuously moved relative to the image sensor by the transport device along the transport path.

[0010] The object of the present invention is to further improve a device of the aforementioned type. In particular, the device should require little installation space and be able to deliver inspection results with high reliability.

[0011] To solve the problem, an inspection device according to claim 1 is proposed. Various embodiments and further developments of the solution are the subject of the dependent claims.

[0012] terms

[0013] Some of the terms used herein to describe the present solution are explained in more detail below:

[0014] The term "physical object" or simply "object," as used herein, refers to a material object, that is, something that occupies space and has mass. In particular, a mass-bearing industrial product is therefore a physical object. This includes, in particular, an electrode for a galvanic cell, especially a lithium-ion cell or battery, or a precursor to such an electrode, a catalyst-coated membrane, a gas diffusion layer, or a membrane electrode assembly (MEA) as a precursor to a fuel cell.

[0015] The term "line camera", as used herein, refers to an image sensor or camera of a digital camera type that has a digital image resolution of M x K camera pixels, wherein

[0016] (i) M > 1000 ■ K and K < 256, and / or

[0017] (ii) M > K with K = 1 holds. 120637P898PC

[0018] - 3 -

[0019] M denotes the number of camera pixels per line, and K the number of lines. In particular, a line scan camera can therefore have only a single (K = 1) radiation-sensitive line (line sensor) – in contrast to a two-dimensional sensor, which typically has a multitude of > 256, and especially > 3, lines. The camera pixels can each have several subpixels for different colors, e.g., according to the RGB color model or another color model.

[0020] The term "contact image sensor" or synonymous "Contact Image Sensor (CIS)," as used herein, refers to an image sensor of a digital camera type, usually designed as a line scan camera. These typically contain several thousand light-sensitive points (pixels) arranged in a

[0021] Row. Each of these points contains a tiny lens, often made of plastic. For image capture, the sensor requires almost direct contact with the original object, such as the physical object to be photographed.

[0022] The term "partially reflective mirror," as used herein, refers to a mirror that partially transmits and partially reflects light within a specific wavelength range. For example, the mirror could be a half-mirror that reflects light at one angle and transmits it at another.

[0023] The term "diffuser," as used herein, refers to a component of the inspection device that distributes the light generated by the lighting device in various directions to ensure uniform illumination of the object's surface being inspected. The diffuser may, for example, have a matte surface or a special structure that scatters the light in different directions.

[0024] The term "imaging device for focusing the light," as used herein, refers to a component of the illumination device comprising one or more optical elements, such as lenses, mirrors, or prisms, which focus the light produced by the illumination device onto the surface of the object to be inspected in order to achieve the most uniform and intense illumination possible. 120637P898PC

[0025] - 4 - The term "transport path" for an object, as used herein, refers to the route or path the object travels during its transport. This includes the sequence of locations through which the object is transported by the transport device. In particular, the term may also refer only to that segment of the total transport path along which the object is transported by the transport device while being scanned by the image sensor.

[0026] Any terms used herein, such as "comprises," "includes," "includes," "features," "has," "with," or any other variant thereof, are intended to cover non-exclusive inclusion. For example, a method or apparatus that includes or features a list of elements is not necessarily limited to those elements but may include other elements not expressly listed or inherent in such method or apparatus.

[0027] Furthermore, unless explicitly stated otherwise, "or" refers to an inclusive "or" and not an exclusive "or". For example, a condition A or B is satisfied by one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

[0028] The terms "ein" or "eine," as used here, are defined as "one or more." The terms "ein anderer" and "ein Weitere," as well as any other variant thereof, are to be understood as "at least one more."

[0029] The term "plural", as it may be used here, is to be understood in the sense of "two or more".

[0030] The terms “first”, “second”, “third”, and similar terms in the description and claims are used to distinguish between similar or otherwise identically named elements and not necessarily to describe a sequential, spatial, or chronological order. It is understood that the terms used in this way may be interpreted in appropriate manner.

[0031] - 5 -

[0032] Under certain circumstances, the embodiments of the solution described herein are interchangeable and the embodiments of the solution described herein may also function in sequences other than those described or illustrated here.

[0033] The terms "configured" or "set up" to perform a specific function (and any variations thereof), as used herein, mean that a device or component thereof already exists in a configuration or setting capable of performing the function and / or that it is adjustable—i.e., capable of assuming a selectable configuration within a defined configuration space—so that it can perform the function after appropriate adjustment. Configuration can be achieved, for example, by adjusting parameters, such as those of a process sequence, or by using switches or similar devices to activate or deactivate functionalities or settings. In particular, the device may have several predetermined configurations or operating modes, allowing configuration by selecting one of these configurations.Operating modes can occur.

[0034] A first aspect of the proposed solution concerns an inspection device for image sensor-based inspection of an object. The inspection device features:

[0035] (i) a transport device for transporting a physical object to be inspected along a transport path;

[0036] (ii) an image sensor system comprising at least one image sensor for scanning the object at least in sections along a viewing direction while the object is continuously moved relative to the image sensor system along the transport path by the transport device; and

[0037] (iii) a lighting device for illuminating a surface of the object to be inspected in a wavelength range detectable by the image sensor, so that the image sensor can detect the surface in such an illuminated area, at least in sections. 120637P898PC

[0038] - 6 -

[0039] The image sensor assembly comprises a number N, with N > 1, of digital line scan cameras configured individually or cumulatively as contact image sensors (CIS), each with a plurality of camera pixels arranged in a line and each pixel having a lens. The lines of the N line scan cameras run perpendicular to the transport path. The illumination device is configured to generate light for illuminating the surface of the object to be inspected and to direct it along a beam path whose direction coincides with the viewing direction or deviates from the orthogonal by at most 30°, preferably at most 15°, particularly preferably at most 5°, or even only 1°.

[0040] This specific choice of image sensor technology allows for a very small distance between the object being imaged, specifically its surface to be inspected, and the image sensor itself, thus enabling a very compact design. To compensate for the typically shallow depth of field of the contact image sensors used and to ensure high inspection quality, the object is illuminated with light that is at least approximately coaxial, meaning predominantly along an illumination direction that is at least nearly parallel to, or at only a small angle to, the viewing direction, particularly an optical axis and thus the main "viewing direction" of the image sensor. This is especially advantageous for quality assurance during inspection when the surface to be inspected is uneven, particularly irregularly uneven.This can be particularly the case with battery electrodes if the electrode material may have a wavy surface during its transport along the transport path.

[0041] The following describes various exemplary embodiments of the inspection device, which can be combined with each other as desired, unless this is expressly excluded or technically impossible.

[0042] In some embodiments, the lighting device has a partially transparent mirror which is arranged in the field of view of the image sensor and in the beam path of the light generated by the lighting device and 120637P898PC

[0043] - 7 - is configured so that the viewing direction coincides with the direction of the light beam path after its deflection at the semi-transparent mirror or differs from each other by a maximum of 30°. The arrangement of the semi-transparent mirror in the field of view of the image sensor means that the mirror is positioned so that the image sensor can detect the object through the mirror along the optical axis running through it, provided the object is positioned such that the optical axis passes through the surface to be inspected. This can be achieved, for example, by arranging the mirror at an angle of 45° to the optical axis of the image sensor.

[0044] In this context, the configuration of the semi-transparent mirror in the beam path of the light generated by the lighting device means that the mirror is oriented so that the light from the lighting device falls onto the mirror and is deflected by it. This can be achieved, for example, by positioning the mirror at an angle of 45° to the light beam path. Specifically, this can also mean that the mirror is positioned at an angle of 45° to the optical axis of the image sensor, as mentioned previously. This enables precise and effective illumination of the object's surface to be inspected, as the light is directed exactly onto the surface that the image sensor is intended to scan during the inspection.Furthermore, the use of a semi-transparent mirror can help to regulate the intensity of the light and prevent overexposure of the image sensor.

[0045] In some embodiments, the lighting device further includes a diffuser configured to scatter the light before it strikes the mirror. By using a diffuser, the lighting device can distribute the light in such a way that the surface of the object being inspected is evenly illuminated, resulting in improved image quality of the images captured by the image sensor.

[0046] In some embodiments, the illumination device includes an imaging device for focusing the light. The imaging device for focusing the light may, for example, include a converging lens or a combination of converging lenses that focus the light from a light source onto the 120637P898PC

[0047] - 8 - the surface of the object to be inspected is focused. Alternatively, the imaging device may also include an arrangement of mirrors or prisms that direct the light onto the surface of the object to be inspected. The imaging device may also include a combination of different optical elements to achieve optimal focusing of the light onto the surface of the object to be inspected.

[0048] Focusing the light onto the surface of the object being inspected is important to ensure high-quality results. Focusing the light allows for even and intense illumination of the surface, which in turn enables precise inspection.

[0049] The lighting system incorporates an imaging device for focusing the light, enabling targeted and concentrated illumination of the object's surface being inspected. Focusing the light allows for a higher light intensity on the surface, resulting in improved illumination and thus higher image quality. Furthermore, the imaging device contributes to more efficient operation and reduced energy consumption, as the light is focused precisely on the surface being inspected and not unnecessarily emitted in other directions.

[0050] In some embodiments, the imaging device comprises a plurality of focusing lenses arranged one behind the other and adjacent to each other in the light beam path. With appropriate lens selection, this allows for a particularly space-saving implementation of the focusing mechanism, since the focusing effect of a long lens, which thus occupies a large area, can be achieved by two or more short lenses arranged one behind the other, which together require less space. Furthermore, the arrangement of multiple lenses can contribute to making the illumination device more flexible and adaptable to different object sizes and shapes, especially if the illumination device is designed such that the distance between the lenses is variably adjustable and / or at least one of the lenses is interchangeable with another, non-identical lens. 120637P898PC

[0051] - 9 -

[0052] In some embodiments, the imaging device has a rod-shaped focusing lens for focusing the light generated by the illumination device. Thus, instead of a point or circular focus area, the focus can have an elongated, in particular linear, line-shaped, focus area, thereby illuminating the field of view of an associated line camera brightly and largely homogeneously, thus contributing to achieving high inspection quality.

[0053] In some embodiments, the inspection device further includes a second mirror configured to deflect the light onto the semi-transparent mirror. Such a second mirror can offer several advantages. Using a second mirror allows for optimization of the light path, resulting in more efficient illumination of the object's surface being inspected. This can be particularly beneficial for objects with complex geometries or those requiring illumination at a specific angle. It also allows for a non-linear light path, especially an angled one, leading to the first mirror, which can be advantageous for achieving a space-saving and, above all, compact design of the entire lighting system.Furthermore, the second mirror can help increase the light intensity, leading to better image quality and improved detection of defects or irregularities on the object's surface. In addition, using a second mirror can increase the flexibility of the inspection device, as the mirror can be positioned to direct light from various sources onto the semi-transparent mirror.

[0054] In some embodiments, the inspection device further includes an adjustment mechanism for setting a variable object distance between at least one contact image sensor and the transport path, such as a movable surface of the transport device configured as a transport surface for the object, e.g., as the transport surface of a conveyor belt. This allows for flexible adaptation to different object sizes and shapes, making the inspection device more universally applicable. By adjusting the distance, the contact image sensor can be optimally positioned to inspect the surface of the object.

[0055] - 10 - to precisely capture, especially to move them into focus of the optics (focusing), resulting in improved image quality and higher inspection accuracy. In addition, the adjustment device can also help adapt the image sensor to different lighting conditions by varying the distance between the contact image sensor and the object to achieve the optimal lighting situation.

[0056] In some embodiments, the transport device is configured to move the object relative to the image sensor in such a way that at least two opposite sides of the object can be simultaneously or sequentially captured by the image sensor. This allows for particularly efficient inspection. The efficiency gain can relate, firstly, to the fact that one and the same image sensor can be used to inspect both sides, thus eliminating the need for duplication. Secondly, in the case of simultaneous (i.e., parallel in the process sense) inspection, the throughput time for the overall inspection of both sides can be reduced.

[0057] A second aspect of the proposed solution concerns a method for image sensor-based inspection of a physical object. This method includes:

[0058] (i) Transporting a physical object to be inspected along a transport path;

[0059] (ii) at least partial image-sensor scanning of the object while it is continuously moved along the transport path relative to an image sensor used for scanning;

[0060] (iii) Illuminating a surface of the object to be inspected in a wavelength range detectable by the image sensor, so that the image sensor can detect the surface at least section by section in such an illuminated surface area;

[0061] The image sensor system comprises a number N, with N > 1, of digital line scan cameras configured individually or cumulatively as contact image sensors (CIS), each with a plurality of camera pixels arranged in a line and each pixel having a lens, and the lines of the N line scan cameras run perpendicular to the transport path. 120637P898PC

[0062] - 11 -

[0063] The lighting device for illuminating the surface of the object to be inspected generates light and directs it along a beam path whose direction (before striking the object) coincides with the viewing direction or deviates from it by no more than 30°.

[0064] Reference is made to all statements concerning the proposed inspection device according to the first aspect for the procedure according to the second aspect, where they are applicable accordingly.

[0065] The invention will be explained in more detail below with reference to figures illustrating only exemplary embodiments. These figures show:

[0066] Fig. 1 shows a side view of a first exemplary embodiment of a system for sensor-based inspection of one or more physical objects,

[0067] Fig. 2 shows a second exemplary embodiment of a system for sensor-based inspection of one or more physical objects,

[0068] Fig. 3 shows a side sectional view of an exemplary first embodiment of an inspection device for sensor-based inspection of one or more physical objects, wherein the inspection device in particular comprises a multi-row light strip, e.g. LED strip, as a light source, a partially transparent mirror and a diffuser.

[0069] Fig. 4 shows a side sectional view of a second embodiment of an inspection device for sensor-based inspection of one or more physical objects, wherein the inspection device in particular has a partially transparent mirror with a different inclination than in Fig. 3 and a single-row light strip, e.g. LED strip, as a light source, 120637P898PC

[0070] - 12 -

[0071] Fig. 5 is a schematic representation to illustrate the geometric relationship, i.e., the at least approximately coaxial course of the viewing direction of the image sensor and the beam path of the light from the illumination device before it hits the object in a corresponding inspection device.

[0072] Fig. 6 shows a schematic representation of a top view of three different variants of an image sensor system, which includes one or more (here by way of example one or two) digital line scan cameras of the CIS type,

[0073] Fig. 7 shows a side sectional view of a third embodiment of an inspection device for sensor-based inspection of one or more physical objects, wherein the inspection device in particular has a lens as an imaging device for focusing the light emitted by the light source,

[0074] Fig. 8 shows a side sectional view of a fourth embodiment of an inspection device for sensor-based inspection of one or more physical objects, wherein the inspection device in particular has several, here by way of example two, thin lenses arranged one behind the other as an imaging device for focusing the light emitted by the light source,

[0075] Fig. 9 shows a perspective view of a possible embodiment of the respective lens(es) from Fig. 7 or 8 as a rod lens and

[0076] Fig. 10 shows a side sectional view of a fifth embodiment of a

[0077] Inspection device for sensor-based inspection of one or more physical objects, wherein the inspection device particularly comprises a second mirror for deflecting the light emitted by the light source before it strikes the semi-transparent (first) mirror. 120637P898PC

[0078] - 13 -

[0079] For all the aforementioned embodiments of the inspection device 1, it is the case that they may in particular be part of a system 2 according to Fig. 1 or 2 or may themselves also contain its additional components.

[0080] In the figures, identical reference symbols denote identical, similar, or corresponding elements. Elements depicted in the figures are not necessarily shown to scale. Rather, the various elements depicted in the figures are represented in such a way that their function and general purpose are understandable to a person skilled in the art. Connections and couplings between functional units and elements shown in the figures can, unless expressly stated otherwise, also be implemented as indirect connections or couplings. Functional units can, unless otherwise specified or implied, be implemented in particular as hardware, software, or a combination of hardware and software.

[0081] Figure 1 illustrates a first embodiment of a system 2 for sensor-based inspection of one or more physical objects 3. The system 2 can be referred to as an inspection device in its entirety or as containing such a device. For the sake of clarity, a nomenclature is used below whereby the inspection device 1 forms part of the system 2. In principle, this allows for the inspection of a wide variety of objects 3 with essentially flat surfaces facing each other. Accordingly, the objects 3 can be, in particular, ribbon-shaped, foil-shaped, or sheet- or plate-shaped. In the following, without this being to be understood as a limitation, examples of objects 3 that are foil- or plate-shaped electrodes for galvanic cells, especially for lithium-ion cells, are discussed.

[0082] The device comprises a transport system consisting of a first vacuum conveyor belt 4 and a second vacuum conveyor belt 5, each configured to transport the objects 3 along a transport path in a transport direction x at a speed v that can be constant or variable over time. The two vacuum conveyor belts are arranged relative to each other such that an object 3 can initially be transported lying down on the first vacuum conveyor belt 4, and subsequently suspended.

[0083] - 14 - to be transported further by the second vacuum conveyor belt 5 (or vice versa, not shown). For this purpose, the two vacuum conveyor belts overlap in a transfer area and are spaced apart from each other in such a way that the objects 3 can be inserted into the resulting gap in the transfer area and can be suctioned onto the second vacuum conveyor belt 5 in order to be transported further while suspended from it.

[0084] Accordingly, in the area of ​​the first vacuum conveyor belt 4, a first (upper) main surface of the respective object 3 is accessible, while its second main surface, opposite the first main surface, rests on the first vacuum conveyor belt 4. In the area of ​​the second vacuum conveyor belt 5, the object 3 rests with its first main surface suspended from the second vacuum conveyor belt 5, while its second (lower) main surface is accessible.

[0085] To enable image-sensor-based acquisition of the two main surfaces, the inspection device 1 has a separate inspection device 1 for each main surface, which includes an image sensor 6 with N digital line cameras 7, with N > 1, in particular a group of several line cameras 7 arranged coaxially (along the Z-direction) and thus transversely, in particular orthogonally, to the transport direction x, adjacent to each other (see Fig. 6). In the following, it is assumed by way of example that at least one or both inspection devices 1 have several line cameras 7, i.e., that N > 1 applies.

[0086] These line scan cameras 7 are configured to scan the object 3 being transported along the respective inspection device 1 during its transport, in order to generate corresponding image material (image data) that represents at least a section of the scanned surface and can serve as the basis for subsequent image evaluation by an image evaluation unit 8 to detect defects, in particular any particles present, on or in the respective surface. The image evaluation unit 8 can, in particular, also serve as a control unit for the inspection device 1, especially for controlling 120637P898PC

[0087] - 15 - of their individual functional components and their interaction, be configured.

[0088] Each of the two inspection devices 1 is equipped with a respective shielding device 9 in the form of a darkroom, configured to provide extensive shading of the field of view of the line scan cameras 7 with respect to radiation originating from outside the respective shielding device 9, in particular stray light. For the purpose of illuminating the surfaces of the objects 3 to be scanned by the line scan cameras 7, each of the darkrooms is provided with a lighting device comprising at least one light source 10, which may in particular have one or more light-emitting diodes as radiation sources. Further details of the inspection devices 1 will be discussed below with reference to the additional figures.

[0089] Each of the two inspection devices 1 is preceded by a cleaning device 11 (referring to the transport direction x). Each cleaning device 11 is configured to clean the surface of the objects 3 to be scanned by the subsequent inspection device 1, in particular by contactless suction. This allows, in particular, the removal of adhering particles and thus increases the yield of defect-free objects 3 according to the subsequently generated inspection result.

[0090] Having now explained the inspection section of Annex 2, we will now discuss a preparatory section of Annex 2 that precedes the inspection section and serves to feed and separate the objects 3 to be inspected. In the preparatory section, Annex 2 has a supply roll 12 for providing a ribbon- or film-shaped starting substrate 13, in particular an electrode substrate (such as a metal foil, which may already be coated with an anode or cathode material). Furthermore, the preparatory section of Annex 2 includes a separating device 14, which may be designed in particular as a punch, for example as a roller punch, which serves to separate individual objects 3, in particular electrodes (possibly with their conductor tabs), from the starting substrate 13, in particular by cutting or punching them out. 120637P898PC

[0091] - 16 -

[0092] It is particularly possible that the singulation device 14 comprises a lower tool and an upper tool. The upper tool may include an eccentric drive shaft for cyclically moving a cutting blade or a punch towards the output substrate 13. It is also possible that, in addition to or as a component thereof, a clamping device 15 is provided, which makes it possible to clamp, in particular, individual objects 3 to be cut or punched out of the output substrate 13 before and / or during the cutting or punching process. This makes it possible to cut or punch out the objects 3 with particularly precise positioning. The clamping device 15 may be mechanically connected to the upper tool.

[0093] In particular, this configuration can be designed such that, during operation of the transport device, the clamping device 15 first grasps the output substrate 13 and pulls or pushes it towards the singulation device 14, while the clamping device 15 is released, i.e., the output substrate 13 is not clamped. The pull or push is designed such that the output substrate 13 is brought into a designated cutting or punching position relative to the singulation device 14, so that, when in a subsequent step the clamping device 15 clamps the output substrate 13, while the clamping device 15 returns to its initial position, the output substrate 13 can be singulated into individual objects 3 by the singulation device 14, while it is held in position by the clamping device 15.The continuous transport by the transport device thus only affects the already separated objects 3. The output substrate 13, on the other hand, is transported stepwise, as described, with pauses between the steps during which the separation takes place. As an auxiliary measure, the output substrate 13 can be fixed to a support of the transport device with a clamping force. A storage section (not shown), e.g., a belt buffer, can also be connected upstream of the transport device in the transport direction x to at least temporarily store the output substrate 13. This enables a continuous feed of the output substrate 13 upstream of the transport device. To improve the guidance of the output substrate 13, see 120637P898PC.

[0094] - 17 - to ensure the singulation device 14, one or more guide rollers 16 or rollers may also be present.

[0095] In addition, each inspection device 1 has an adjustment device 17 by means of which the object distance 19 of the image sensor 6, more precisely of at least one line camera 7 of the object 3 to be scanned, measured along the viewing direction 18, can be adjusted (see Fig. 3).

[0096] Fig. 2 shows a second embodiment of the system 2, which is a modification of the embodiment shown in Fig. 1. In contrast to the latter, here only the first vacuum conveyor belt 4 is provided as a single vacuum conveyor belt and a single inspection device 1 with associated shielding device 9.

[0097] To enable double-sided image sensor detection of the objects 3, the system 2 includes a turning device 20 configured to turn an object 3, which is resting with one side on the first vacuum conveyor belt 4, so that it comes to rest with a second side, opposite the first, on the vacuum conveyor belt. This allows the first side to be image sensor detected by the (single) inspection device 1 before turning and the second side after turning. Various configurations are conceivable for the design of the turning device 20, in particular, in addition to the one shown in Fig. 2, configurations where the objects 3 are fed back to the image acquisition unit from the front after turning, i.e., from the end of the vacuum conveyor belt facing the singulation device 14.

[0098] The system 2 can, in turn, include a preparation section (only partially shown in Fig. 2) that corresponds to that of system 2 in Fig. 1. The design of system 2 according to Fig. 2 enables, in particular, the simultaneous image-sensor detection of both sides of the objects 3 using a single inspection device 1, and thus also a particularly compact design.

[0099] Fig. 3 shows a side sectional view of an exemplary first embodiment of the inspection device 1 for sensor-based inspection of one or more 120637P898PC

[0100] - 18 - physical objects 3. The inspection device 1 has an image sensor system 6 which, as described above, has N digital line cameras 7, where N > 1. N can therefore be, in particular, 1 or a small number, such as N = 2 or N = 3. The image sensor system 6 is configured such that it can scan an object 3 to be inspected from a perspective defined by a viewing direction 18 when the object is transported by the transport device through its field of view along a transport path. In the present example, the transport device has the first vacuum conveyor belt 4.

[0101] Furthermore, the inspection device includes a lighting device, which in particular comprises a light source 10. This light source can, in particular, comprise a plurality of individual light emitters 21, such as light-emitting diodes (LEDs). These can, in particular, be arranged in a row (e.g., forming an LED strip) or in a two- or three-dimensional grid. The light source 10 generates light and preferably emits it as a beam.

[0102] The lighting device can also include a diffuser 22, such as a frosted screen, on which the light emitted by the light source 10 is scattered, for example to produce an output beam that has an intensity profile that is at least approximately homogeneous in its center over its cross-section.

[0103] Furthermore, the lighting device includes a partially transparent mirror 23 through which both the viewing direction 18 of the image sensor 6 and a beam path 24 of the light coming from the diffuser 22 pass. The latter is deflected by the partially transparent mirror 23 and thereby directed onto the transport path and any object 3 passing the inspection device 1 there. The partially transparent mirror 23 is arranged, and in particular oriented, such that the light from the lighting device, after its deflection by the partially transparent mirror 23, is at least approximately coaxial with the viewing direction 18. This means that the angle 25 between the beam path 24 of the light after deflection by the partially transparent mirror 23 and the viewing direction 18 is at most 30°. They can, in particular, be parallel to each other.Specifically, the semi-transparent mirror 23 can be positioned at an angle of inclination 26 of 45° to the 120637P898PC.

[0104] - 19 -

[0105] The viewing direction 18 and / or the direction of the beam path 24 of the incident light from the light source 10 are oriented. The light reflected back from the illuminated object 3 to the partially transparent mirror 23 can at least partially pass through the partially transparent mirror 23 to reach the image sensor 6 and be detected there by the image sensor.

[0106] The object distance 19 between the image sensor 6 and the object 3 can be adjusted using the adjustment device 17 already mentioned in relation to Fig. 1. This is particularly advantageous because the at least one line scan camera 7 of the image sensor 6 is a contact image sensor (CIS) camera. While this type of camera offers the advantages of a very low profile and the ability to adjust the object distance 19 very small, it typically has the disadvantage of a shallower depth of field compared to many other camera types, especially conventional CCD cameras (CCD = charge-coupled device). Therefore, adjusting the object distance 19 to a suitable value helps to achieve or ensure the desired inspection quality. This is especially true if the inspection device 1 is intended for inspecting objects 3 of different sizes, particularly heights.

[0107] Fig. 4 shows a side sectional view of a second embodiment of an inspection device 1 for sensor-based inspection of one or more physical objects 3. It largely corresponds to the inspection device 1 from Fig. 3, but differs from it by a different inclination angle 26 of the semi-transparent mirror 23 and in that the light source 10 has only a single, single-row light strip, e.g., an LED strip. The beam path 24 of the light source 10 is reflected here (at least partially) at the semi-transparent mirror 23 at a larger reflection angle than the corresponding angle 25 from Fig. 3, while the direction of the beam path 24 after reflection continues to be essentially coaxial with the viewing direction 18. In this way, the lateral dimension along the transport direction x can be shortened in particular, and thus a particularly compact design can be achieved in this dimension as well.

[0108] Fig. 5 shows a schematic representation to illustrate the geometric relationship, i.e., the at least approximately coaxial course, the viewing direction 18 of the image sensor 6 and the beam path 24 of the light of the 120637P898PC

[0109] - 20 -

[0110] Lighting device before impact on the object 3 in a solution-oriented inspection device 1, for example according to Fig. 1 or 2.

[0111] The at least approximately coaxial path is defined such that the angle 25 is a maximum of 30°. In particular, it can be less than 1°, so that the viewing direction 18, which corresponds or can correspond in particular to an optical axis of the image sensor 6, and the direction of the beam path 24 are essentially parallel to each other or coincide.

[0112] Fig. 6 shows a schematic representation of a respective top view of three different variants of an image sensor system 6, which has one or more (here by way of example one or two) digital line cameras 7 of the CIS type.

[0113] In variant (a), the image sensor 6 has only a single line camera 7, which has a plurality of camera pixels 27 arranged along a typically linear line. A lens 28 is mounted on or in front of each camera pixel 27, which together enable the line camera 7 to take sharp images from a very short distance, i.e., at a small object distance 19, thus forming a CIS-type line camera 7.

[0114] In variant (b), several such CIS-type line scan cameras 7 are arranged parallel to each other, in particular directly adjacent to each other. However, as illustrated, the line scan cameras 7 can be arranged offset from one another such that their camera pixels 27 are offset from each other along the line direction. In this way, an even higher overall camera resolution can be achieved.

[0115] In variant (c), two or more of the aforementioned CIS-type line cameras 7 are arranged parallel to each other, but with a gap between the lines. This can be advantageously used to scan the locations on the object 3 multiple times at different times and from slightly different camera perspectives due to the spacing, in order to achieve higher inspection quality in cases where the scanned surface or the relative position of particles on it changes during scanning, or where any defects or contamination of 120637P898PC

[0116] - 21 - are more easily recognizable from one perspective than from others. It is also conceivable that the inspection quality can be improved by sensor fusion, i.e., the combined evaluation of the image data supplied by the various line scan cameras 7. This also applies to variant (b) or other (not illustrated) conceivable variants with multiple line scan cameras 7.

[0117] Fig. 7 shows a side sectional view of a third embodiment of an inspection device 1 for sensor-based inspection of one or more physical objects 3. It largely corresponds to the inspection device 1 from Fig. 3, but differs from it by the addition of a focusing lens 29, in particular a thick lens 28, as an imaging device 30 for focusing the light emitted by the light source 10. The focusing lens 29 is arranged in the beam path 24 of the light between the light source 10 and the diffuser 22 and, in conjunction with the diffuser 22, serves to define a desired intensity profile in the cross-section of the beam path 24, in particular such that, after deflection at the partially transparent mirror 23, a sufficiently high illuminance is present on the object surface 3 in accordance with the inspection requirements.

[0118] Fig. 8 shows a side sectional view of a fourth embodiment of an inspection device 1 for sensor-based inspection of one or more physical objects 3. It largely corresponds to the inspection device 1 from Fig. 7, but differs in that, instead of a single focusing lens 29, the imaging device 30 consists of two lenses 28, in particular short converging lenses, arranged one behind the other in the beam path 24. The lens pair 31 can be designed to be more space-saving, especially in the x-direction, than a single focusing lens 29 with the same imaging properties.

[0119] Fig. 9 shows an exemplary embodiment of a rod lens 32 that can be used as a focusing lens 29. The lenses 28 of the lens pair 31 can also be designed according to this embodiment. Instead of a circular shape, which is typical for many focusing lenses 29, the rod lens 32 has a rod-shaped form, so that it can focus incident light not on a circular focal point, but instead on a focus strip, in particular a linear one. 120637P898PC

[0120] - 22 -

[0121] Fig. 10 shows a side sectional view of a fifth embodiment of an inspection device 1 for sensor-based inspection of one or more physical objects 3. It largely corresponds to the inspection device 1 from Fig. 3, but differs in that a second mirror 33 (typically not partially opaque) is arranged and oriented in the beam path 24 of the light source 10 upstream of the diffuser 22 such that the light source 10 can be positioned at another suitable location, in particular above the second mirror 33, without affecting the direction of the beam path 24 downstream of the second mirror 33. Upstream of the second mirror 33, the beam path 24 of the light source 10 can, in particular, run orthogonally to the transport direction x, i.e., opposite to the y-direction. This arrangement allows the inspection device 1 to be designed to be particularly compact in the x-direction.

[0122] While at least one exemplary embodiment has been described above, it should be noted that a large number of variations exist. It should also be noted that the described exemplary embodiments are merely non-limiting examples, and it is not intended to restrict the scope, applicability, or configuration of the devices and methods described herein. Rather, the preceding description will provide the person skilled in the art with guidance for implementing at least one exemplary embodiment. It is understood that various modifications to the function and arrangement of the elements described in an exemplary embodiment can be made without derogating from the subject matter defined in the appended claims and their legal equivalents.

[0123] 120637P898PC

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[0125] Reference symbol list

[0126] 1 Inspection device

[0127] 2 Annex

[0128] 3 objects

[0129] 4 first vacuum conveyor belt

[0130] 5 second vacuum conveyor belt

[0131] 6 Image sensors

[0132] 7-line camera

[0133] 8 Image evaluation unit

[0134] 9 Shielding device

[0135] 10 light sources

[0136] 11 Cleaning equipment

[0137] 12 storage rolls

[0138] 13 Starting substrate

[0139] 14. Single-person access control device

[0140] 15 Fixing device

[0141] 16 leadership roles

[0142] 17 Adjustment device

[0143] 18. Viewing direction

[0144] 19 object distance

[0145] 20 reversing device

[0146] 21 light sources

[0147] 22 Diffuser

[0148] 23 semi-transparent mirrors

[0149] 24 Beam path

[0150] 25 angles

[0151] 26 tilt angles

[0152] 27 camera pixels

[0153] 28 lens

[0154] 29 Focusing lens

[0155] 30 Imaging device

[0156] 31 pairs of lenses 120637P898PC

[0157] - 24 -

[0158] 32 rod lens

[0159] 33 second mirror

[0160] 34 procedures

[0161] 35 Image sensor v Speed ​​x Transport direction

Claims

120637P898PC - 25 - Patent claims 1. Inspection device (1) for image sensor-based inspection of an object (3) wherein the inspection device (1) comprises: a transport device for transporting a physical object (3) to be inspected along a transport path; an image sensor (6) with at least one image sensor (35) for at least sectionally scanning the object (3) along a viewing direction (18) while the object (3) is continuously moved by the transport device along the transport path relative to the image sensor (6); and an illumination device for illuminating a surface of the object (3) to be inspected in a wavelength range detectable by the image sensor (6), so that the image sensor (6) can at least sectionally image the surface in such an illuminated surface area;wherein the image sensor (6) comprises a number N, with N > 1, of individually or cumulatively configured digital line scan cameras (7) configured as contact image sensors (CIS), each having a plurality of camera pixels (27) arranged in a line and each having a lens (28), and wherein the lines of the N line scan cameras (7) each run transversely to the transport path; and wherein the illumination device is configured to generate light for illuminating the surface of the object (3) to be inspected and to direct it along a beam path (24) whose direction coincides with the viewing direction (18) or deviates from it by no more than 30°.

2. Inspection device (1) according to claim 1, wherein the lighting device has a partially transparent mirror (23) which is arranged and configured in the field of view of the image sensor (6) and in the beam path (24) of the light generated by the lighting device such that the viewing direction (18) corresponds to the direction of the beam path (24) of the 120637P898PC - 26 - The light, after its deflection at the partially transparent mirror (23), coincides or deviates from each other by no more than 30°.

3. Inspection device (1) according to claim 2, wherein the lighting device further comprises a diffuser (22) configured to scatter the light before it strikes the semi-transparent mirror (23).

4. Inspection device (1) according to one of the preceding claims, wherein the lighting device has an imaging device (30) for focusing the light.

5. Inspection device (1) according to claim 4, wherein the imaging device (30) has a plurality of focusing lenses (29) arranged one behind the other and adjacent to each other in the beam path (24) of the light.

6. Inspection device (1) according to claim 4 or 5, wherein the imaging device (30) has a rod-shaped focusing lens (29) for focusing the light generated by the illumination device.

7. Inspection device (1) according to one of the preceding claims, further comprising a second mirror (33) configured to deflect the light onto the partially transparent mirror (23).

8. Inspection device (1) according to one of the preceding claims, further comprising an adjustment device (17) for setting a variable object distance (19) of at least one contact image sensor from the transport path.

9. Inspection device (1) according to one of the preceding claims, wherein the transport device is configured to move the object (3) relative to the image sensor (6) in such a way that at least two opposite sides of the object (3) can be image-sensored simultaneously or sequentially by the image sensor (6). 120637P898PC - 27 - 10. Method for image sensor-based inspection of a physical object (3), wherein the method comprises: Transporting a physical object (3) to be inspected along a transport path; at least sectionally scanning the object (3) with an image sensor while it is continuously moved along the transport path relative to an image sensor (6) used for scanning; Illuminating a surface of the object (3) to be inspected in a wavelength range detectable by the image sensor (6), such that the image sensor (6) can detect the surface in such an illuminated surface area at least sectionally; wherein the image sensor (6) comprises a number N, with N > 1, of digital line cameras (7) designed individually or cumulatively as contact image sensors (CIS), each with a plurality of camera pixels (27) arranged in a line and each having a lens (28), and the lines of the N line cameras (7) each run transversely to the transport path; and the illumination device for illuminating the surface of the object (3) to be inspected generates light and directs it along a beam path (24) whose direction coincides with the viewing direction (18) or deviates from it by no more than 30°.

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