METHOD AND DEVICE FOR CHECKING PIPETTE TIPS

Description

[0001] The present invention relates to a method and a device for checking pipette tips and to an injection molding system comprising at least one device for checking pipette tips as described below.

[0002] Pipette tips are typically manufactured using injection molding, with the injection molding machines used typically having a plurality of circularly arranged cavities, each defined by an injection mold. In practice, the problem arises that the pressure conditions occurring during the injection molding process cause an internal mold component to radially shift from its original optimal position over time, resulting in slight changes in the wall thickness of the manufactured pipette tips over time.This, in turn, leads to the different wall sections of the molded pipette tips cooling at different rates, resulting in minimal distortion (curvature of the longitudinal axis) of the pipette tips. The pipette tip outlet opening of pipette tips manufactured at a later time deviates further from an optimal central position than those manufactured after a tool change. If this deviation exceeds a certain level, the pipette tips are no longer usable, as they are no longer suitable for precisely measuring the liquid to be dispensed and / or can no longer be accurately controlled by an automated analyzer or other handling device.

[0003] As a quality assurance measure in pipette tip production, it is known from the prior art, for example from WO 00 / 52987 A1, to transport individual pipette tips by means of a gripper to a camera, which captures image data from different angles of rotation around a longitudinal axis of the pipette tip. This image data is then analyzed with regard to compliance with specified tolerances. However, it has been found that the analysis of the image data recorded from the side is problematic with regard to reliable defect detection, in particular because even straight, i.e. non-distorted pipette tips are recognized as defective if they are not held optimally straight in the gripper. Another disadvantage is that the individual feeding of pipette tips to a single camera means that the quality assurance measure is very time-consuming.

[0004] EP 2913107 A1 discloses a method for assessing pipette tip distortion, in which the distortion is detected using image data. For a pipette tip group comprising a plurality of pipette tips, first and second image data of the pipette tip ends and pipette tip inlet openings are acquired, with the viewing directions of the first and second image acquisition means being opposite one another, and an average value of the deviation mass is then determined based on the deviation mass of the pipette tip outlet openings. This method is, on the one hand, very complex in terms of equipment, since separate first and second image acquisition means are required. Furthermore, determining the target position of the pipette tip outlet openings using the second image acquisition means aligned with the inlet opening of the upper pipette tip end has proven to be difficult or error-prone in practice.For example, the tolerances when determining the target position of the pipette tip using the second image acquisition device and the tolerances when determining the actual position using the first image acquisition device overlap, which can lead to inaccuracies in determining the actual deviation of the pipette tip distortion. Furthermore, with this method, for example, a correctly shaped pipette tip that is tilted in its holder is not detected and rejected as scrap simply because the deviation of the pointed end of the pipette tip from the specified axial direction is considered a defect due to the misalignment of the pipette tip in the holder.

[0005] To reduce these inaccuracies in the holding of pipette tips, DE 10 2017 012 225 A1 proposes a pressure device which, by exerting mechanical force on the pipette tip held in a holder, ensures a particularly well-defined position of the pipette tip in the holder. The pipette tip, arranged with a defined fit on the holder, can thus be subjected to measurement reliably and with a low error tolerance, with the image capture device provided for this purpose recording the position of the free end of the pipette tip. The distortion of the pipette tip is determined as the positional deviation of a predetermined area of ​​the pipette tip held in the holder from a predefined target position of this area for a distortion-free pipette tip. A disadvantage of this method is, on the one hand, that it is very complex in terms of equipment due to the large number of separate devices in the testing device.Furthermore, for the simultaneous testing of a plurality of pipette tips, a type of revolving mechanism for feeding a single pipette tip to the pressing device or the use of several image capture devices corresponding to the number of pipette tips held on the holder is proposed, which further increases the equipment complexity and the costs of such a testing device.

[0006] WO 2020 / 079170 A1 discloses a method and a device for checking pipette tips. A first detection device detects a reference region of a supported pipette tip extending in the axial direction, and the symmetry axis of the pipette tip is calculated based on the reference region. To detect a curvature or slant of the injection-molded part, the position of a symmetry axis section spaced apart from the reference region in the axial direction is detected by a second detection device and compared with the previously calculated symmetry axis. However, due to the individual feeding of pipette tips to the device, checking the pipette tips remains very time-consuming.

[0007] Based on the aforementioned prior art, the present invention is based on the object of eliminating these and other disadvantages of the prior art and, in particular, of providing an advantageous method for checking the openings and warpage of elongated injection-molded parts, such as pipette tips in particular, which can be carried out quickly, reliably, and with minimal effort in terms of the required testing device. Furthermore, the present invention is based on the object of providing a testing device suitable for carrying out the method.

[0008] The object is achieved by a method for checking pipette tips, a device for checking pipette tips, which device is preferably designed to carry out the method according to the invention, and an injection molding system comprising an inventive device for checking pipette tips according to the independent patent claims. Further advantageous embodiments are the subject of the dependent patent claims. Unless reference is made to a specific embodiment of the method according to the invention or to a specific embodiment of the device according to the invention in the following description of advantageous embodiments, such advantageous embodiments fundamentally relate to all of the embodiments of the method according to the invention or the device according to the invention described herein.

[0009] In particular, the object is achieved by a method for checking pipette tips each extending along a longitudinal axis (L), wherein the method according to the invention comprises the following steps: a) providing pipette tips which are arranged in a first carrier; b) receiving pipette tips from the first carrier by a holding device comprising a plurality of receiving elements for each receiving a pipette tip; c) capturing first image data of the respective pipette tip outlet openings of the pipette tips received by the holding device by a first image capturing device; d) capturing second image data of the pipette tips held in the holding device by a second image capturing device.During the acquisition of the second image data, the optical axis of the second image capture device is aligned transversely to the respective longitudinal axis of the pipette tips held in the holding device and to the partial segments of the respective pipette tip lateral surfaces of the held pipette tips facing the second image capture device. The second image data of several of the pipette tips held in the holding device are acquired simultaneously. Preferably, the second image data of all of the pipette tips held in the holding device are acquired simultaneously; e) Determining whether the first and / or second image data lie within predefined admissibility limits or not.This is done with the aid of a data processing system; f) the holding device ejects those pipette tips whose first and / or second image data determined in step e) lie outside the predefined admissible limits into a waste container; g) the pipette tips whose first and second image data determined in step e) lie within the predefined admissible limits are dispensed into a second carrier. The second carrier can, in particular, be a rack.

[0010] In a first embodiment of the method according to the invention, this comprises the following steps: a) providing pipette tips which are arranged in a first carrier in a first matrix arrangement of rows and columns in the first carrier; b) receiving a row or column of pipette tips from the first matrix arrangement by a holding device comprising a plurality of receiving elements arranged in a row, each for receiving a pipette tip. The longitudinal axes of the pipette tips held by the receiving elements lie essentially in a common plane; c) capturing first image data of the respective pipette tip outlet openings of the pipette tips received by the holding device by a first image capture device.During the acquisition of the first image data, the optical axis of the first image capture device is aligned, in particular parallel, with the respective longitudinal axis of the pipette tips held in the holding device and is aligned with the pipette tip outlet openings; d) Acquisition of second image data of the pipette tips held in the holding device by a second image capture device. During the acquisition of the second image data, the optical axis of the second image capture device is aligned essentially perpendicularly to the plane defined by the held pipette tips and to the partial segments of the respective pipette tip lateral surfaces of the held pipette tips facing the second image capture device, so that all pipette tips held in the holding device are arranged essentially in one image plane of the second image capture device.The second image data of all pipette tips held in the holding device are recorded simultaneously; e) determining whether the first and / or second image data lie within predefined acceptance limits or not with the aid of a data processing system; f) ejecting those pipette tips whose first and / or second image data determined in step e) lie outside the predefined acceptance limits into a waste container by the holding device; g) dispensing those pipette tips whose first and second image data determined in step e) lie within the predefined acceptance limits into a second carrier having a plurality of holes in a second matrix arrangement of rows and columns, the holes of which are suitable for holding the dispensed pipette tips.In method step g), the pipette tips are dispensed by the holding device in such a way that the respective rows or columns of holes of the second carrier are filled one after the other without one or more empty holes remaining between two dispensed pipette tips.

[0011] The method according to the invention allows the efficient assessment of all pipette tips to determine deviations of the pipette tips from a predefined norm using two image capture devices. For example, the deviation of the pipette tips from a norm is a distortion of the injection-molded part or a deviation of the pipette tips from a desired shape. A norm deviation of the pipette tips is measured as the positional deviation of the pipette tip opening or a predetermined area of ​​the pipette tip surface from predefined target positions of these areas. The theoretical center line is recorded for each image. A systematic error caused by diagonally clamped test pieces, i.e. pipette tips, can thus be filtered out. In other words, the distortion of a pipette tip to be tested is measured by comparison with a previously measured, undistorted pipette tip.A pipette tip deviation from the standard also refers to the deviation of its surface quality from a predetermined target value. The surface quality is characterized in particular by the presence or absence of scratches, cloudy spots, perforations, or other damage. By arranging the supported pipette tips in a single image plane of the second image acquisition device, the second image data can be captured with particular precision. Rotating the pipette tips on their respective mounting elements enables the geometry of the pipette tips to be captured more precisely.

[0012] In the context of the present invention, the term "matrix arrangement" refers to a preferably regular arrangement of holes designed to hold a pipette tip each, wherein the holes are arranged in rows and columns. Each row comprises n holes, and each column comprises m holes, so that the number of holes contained in the matrix arrangement is the product of n and m. Such matrix arrangements are found, for example, in the containers for pipette tips known from the prior art, so-called racks.

[0013] In the context of the present invention, the term "image capture device" refers to a camera, in particular a camera with a lens and suitable lighting. Telecentric lenses are particularly suitable as lenses, as they significantly reduce negative edge effects on round objects, such as elongated injection-molded parts with a symmetrical axis, especially pipette tips.

[0014] It has been found that pipette tip warpage continues for some time after the actual manufacturing process in an injection molding system. Therefore, for quality assurance purposes, it is advantageous to allow the produced pipette tips to cool completely for a certain period of time, especially for two days, and then assume their final shape. To avoid having to maintain expensive and less available workpiece carriers in the injection molding system for the purpose of temporary storage of the pipette tips to be tested, the pipette tips to be tested can be temporarily stored in racks.

[0015] In an advantageous development of the first embodiment of the method according to the invention, the first carrier, which provides pipette tips in a first matrix arrangement of rows and columns, is a rack. Analogously, the second carrier is a rack having a plurality of holes arranged in a second matrix arrangement of rows and columns.

[0016] According to the invention, it is conceivable that the pipette tips to be tested are picked up from the first carrier by the holding device in step b) and the tested pipette tips are returned to the first carrier in step g), wherein pipette tips from a reservoir of tested pipette tips are used to replace the pipette tips that may have been discarded in step f) and to refill the first carrier.

[0017] According to the invention, it is also conceivable that the pipette tips to be tested are picked up from the first carrier by the holding device in step b) and initially only the first image data of the pipette tips picked up by the holding device are acquired in step c) before the pipette tips tested in step c) are returned to the first carrier in a method step g'). In particular, it is also conceivable that the pipette tips to be tested have not yet completely cooled down when the first image data is acquired by the first image acquisition device in step c). Surprisingly, it has been found that core breakages can be reliably detected even on pipette tips that have not yet completely cooled down by capturing the first image data. This means that core breakages in the injection molding system can be detected and rectified much earlier.

[0018] Following step g'), the previously partially tested pipette tips are again picked up from the first carrier by the holding device in step b), whereupon the pipette tips undergo process steps c) to g) or d) to g) for complete testing.

[0019] In a preferred development of the first embodiment of the method according to the invention, the holding device of the first matrix arrangement removes a complete row or a complete column of pipette tips in step b). Preferably, the holding device removes all pipette tips from a row or a column of a rack in step b).

[0020] This optimizes the efficiency of the method according to the invention, since the pipette tips held by the receiving elements of the holding device are each tested together in the subsequent method steps c) and d), as will be explained in more detail below.

[0021] In a preferred development of the first embodiment of the method according to the invention, the number of receiving elements of the holding device corresponds to the number of pipette tips provided in a row or column of the first matrix arrangement and / or the second matrix arrangement of holes in the second carrier. In other words, the holding device is matched to the first and / or second carriers used in the method according to the invention, which allows the method according to the invention to be carried out particularly cost-effectively.

[0022] It has surprisingly been found that the second image data can also be acquired reliably and satisfactorily if the longitudinal axes (L) of the pipette tips held by the receiving elements in the holding device do not lie essentially in a common plane.

[0023] In a second embodiment of the method according to the invention, the pipette tips provided in step a) are arranged in the first carrier in at least one circular arrangement. Preferably, the pipette tips provided in step a) are arranged in at least one circular arrangement of eight pipette tips evenly spaced from one another in the circumferential direction of the circular arrangement. In this embodiment, the holding device receives a circular arrangement, in particular a complete circular arrangement, of pipette tips from the first carrier in step b). Optionally, before capturing the second image data in step d), the holding device is rotated about its rotational axis by an angle of rotation β such that the contours of at least some of the pipette tips held in the holding device can be captured by the second image capture device.Preferably, the rotation of the holding device about its axis of rotation causes the contours of all pipette tips held in the holding device to be captured by the second image capture device.

[0024] This second embodiment has the additional advantage that, by accommodating pipette tips in a circular arrangement, the inventive device eliminates the need for automation upstream of the device, which converts the circular arrangement, as typically found in the mold of an injection molding machine, into a linear arrangement. The pipette tips can thus be tested while maintaining the mold arrangement of the injection molding machine, without prior reorientation of the pipette tips. This significantly reduces the design and financial outlay, as well as the space requirements, of the inventive device.

[0025] In the context of the present invention, the "axis of rotation of the holding device" is understood to mean the axis of rotation extending in the direction of the pipette tips held by the holding device.

[0026] In the context of the present invention, the term "detectable contours" refers in particular to the contours extending along the longitudinal direction of the pipette tip, so that the respective image capture device can distinguish between pipette tips that are held in the holding device and located in the optical axis of the respective image capture device. In other words, pipette tips whose contours are detectable are not partially or even completely obscured or overlaid by one or more other pipette tips in the optical axis of the respective image capture device to such an extent that they would be indistinguishable. Preferably, the contours are completely detectable, i.e., over substantially the entire length of the respective pipette tips.

[0027] In an advantageous development of the second embodiment of the method according to the invention, the holding device is rotated about its rotational axis during the acquisition of the second image data in step d). The holding device preferably performs at least three-quarters of a rotation about its rotational axis during the acquisition of the second image data, i.e., a rotation of at least 270°. The rotation of the holding device about its rotational axis enables the second image data to be acquired particularly easily and efficiently, since in this case, additional drive means for rotating the individual recording elements can be dispensed with, which significantly reduces the complexity and maintenance requirements of the holding device.

[0028] In an advantageous development of the second embodiment of the method according to the invention, in which the holding device is rotated about its rotation axis during the acquisition of the second image data in step d), the optical axis of the second image acquisition device is further aligned with an illumination device attached to the holding device and arranged in the center of the circular arrangement of pipette tips during the acquisition of the second image data in step d). The illumination device is designed such that it emits light in the direction of the second image acquisition device during the acquisition of the second image data in step d).

[0029] In an advantageous development of the second embodiment of the method according to the invention, the second image data of the pipette tips held in the holding device are additionally acquired by a third image acquisition device in step d). During the acquisition of the second image data, the optical axis of the third image acquisition device is oriented substantially perpendicular to the optical axis of the second image acquisition device and to the partial segments of the respective pipette tip lateral surfaces of the held pipette tips facing the third image acquisition device.

[0030] In this context, depending on the arrangement of the pipette tips held in the holding device in the beam path of the second and third image capture device, it may be necessary or advantageous to rotate the holding device about its axis of rotation by an angle of rotation β before capturing the second image data in step d) in such a way that the contours of a first part of the pipette tips held in the holding device can be captured, preferably completely, by the second image capture device, and that the contours of a second part of the pipette tips held in the holding device can be captured, preferably completely, by the third image capture device.

[0031] The provision of a further image capture device, i.e. the third image capture device, for capturing the second image data makes it possible to reliably test even in the case of pipette tips that are close to one another in the direction of rotation of the circular arrangement, where a single image capture device, i.e. the second image capture device, could no longer detect a gap between the pipette tips imaged adjacently in the beam path, in particular in the area of ​​the respective recording elements, left and right with respect to the longitudinal axis of the respective pipette tips.

[0032] In an advantageous development of the second embodiment of the method according to the invention, an illumination device is attached to the holding device, which divides the circular arrangement of pipette tips on the holding device into two halves. The illumination device has two plane-parallel light-emitting surfaces for emitting light in the direction of the second image capture device and opposite to this direction. The optical axis of the second image capture device is aligned perpendicular to the illumination device attached to the holding device during the acquisition of the second image data in step d). First, the second image data of one half of the pipette tips are acquired, and the holding device is then rotated 180° about its rotation axis before the second image data of the other half of the pipette tips are acquired.Alternatively, a further image capture device can be provided for capturing second image data of the pipette tips held in the holding device. The optical axis of this further image capture device is aligned opposite to the optical axis of the second image capture device. Thus, the second image data of both halves of the circular arrangement of pipette tips are captured simultaneously.

[0033] In order to capture the image data quickly and efficiently, the position of the pipette tips is detected with a measuring device and the first image capture device is thus triggered.

[0034] In a preferred embodiment of the method according to the invention, the first image data are acquired in step c) when the pipette tips held in the holding device are moved transversely to the optical axis of the first image capture device and through the optical axis of the first image capture device relative to one another. The entry of the respective pipette tips, in particular the respective pipette tip outlet openings, into the optical axis of the first image capture device is determined by a measuring device and triggers the acquisition of the first image data by the first image capture device. The measuring device for detecting the entry of the respective pipette tips into the optical axis of the first image capture device is, for example, a light barrier.The light barrier is directed, for example, transversely to the longitudinal axis of the pipette tips and toward the pipette tip outlet opening, so that when the light barrier is interrupted, the acquisition of the first image data by the first image capture device is triggered. According to the invention, it is of course also conceivable for the measuring device for detecting the entry of the respective pipette tips into the optical axis of the first image capture device not to run through the optical axis of the first image capture device, but rather to be arranged upstream of the first image capture device in the direction of movement of the holding device. In this case, the triggering of the acquisition of the first image data can be calculated or adjusted by the distance between the measuring device and the optical axis of the first image capture device as well as the movement speed of the holding device and the first image capture device relative to one another.

[0035] In particular, only the holding device is moved and the first image capture device remains stationary, so that the respective pipette tip outlet openings of the pipette tips held in the holding device are guided past the first image capture device essentially in a single image plane of the first image capture device.

[0036] This allows all pipette tips held in the holding device, in particular the respective pipette tip outlet openings, to be inspected in a single process step, which increases the speed of the inspection. Moving the pipette tip outlet openings past essentially a single image plane of the first image acquisition device further increases the accuracy of the image acquisition.

[0037] In a preferred embodiment of the method according to the invention, step d) comprises the following method steps: i. Taking a first image of the pipette tips held in the holding device. The pipette tips are each in a first position; ii. Rotating the pipette tips held in the holding device about their longitudinal axis by a predetermined angle of rotation α into a second position; iii. Taking a second image of the pipette tips held in the holding device. The pipette tips are each in the second position; The angle of rotation α between the first position and the second position of the pipette tips is at least substantially 90°. Preferably, the angle of rotation α between the first position and the second position of the pipette tips is between substantially 90° and substantially 180°.Particularly preferably, the angle of rotation α between the first position and the second position of the pipette tips is substantially 180°.

[0038] This results in the advantage that the concentricity test of all pipette tips held in the holder can be carried out simultaneously, i.e., quickly, and also with particular precision by rotating the pipette tips by at least substantially 90°. The accuracy of the measurement can be further increased by a further rotation, i.e., a larger angle of rotation α between the first and second positions of the pipette tips. This is particularly the case if additional images of the pipette tips are taken in intermediate positions between the first and second positions.

[0039] Preferably, in addition to the first position and the second position, the pipette tips are rotated to a number of intermediate positions corresponding to the number of additional images for capturing additional images. These intermediate positions lie between the first position and the second position. In other words, the one or more intermediate positions are reached, starting from the first position, by rotating the pipette tips by a rotation angle α', wherein the rotation angle α' is between 0° and 180°. Furthermore, the intermediate positions are preferably evenly distributed between the first position and the second position.

[0040] By capturing additional images using the second image capture device, the accuracy of the inspection is increased.

[0041] Preferably, the number of intermediate positions and the number of additional images is one to four, whereby a particularly favorable ratio between measurement accuracy, amount of data acquired and to be processed and speed of the process is achieved.

[0042] In a preferred embodiment of the method according to the invention, the pipette tips are each held in a force-fitting manner on the receiving elements of the holding device. The force-fitting connection can be achieved in a particularly efficient and reliable manner by applying negative pressure to the pipette tips.

[0043] In a preferred embodiment of the method according to the invention, the pipette tips are positioned between the second image capture device and an illumination device fixed relative to the second image capture device when capturing the second image data in step d). The illumination device emits light onto the second image capture device in the direction opposite to the optical axis of the second image capture device.

[0044] This allows the contrast of the pipette tips positioned in the beam path of the second image acquisition device to be increased relative to the image background formed by the illumination device, which further increases the accuracy of the inspection of the pipette tips in step d).

[0045] In a preferred embodiment of the method according to the invention, the data processing system controls a movement device for the controlled motorized movement of the holding device in the direction of an X, Y, and Z spatial axis. In particular, the movement device is controlled only for the controlled motorized movement of the holding device in the direction of an X and Y spatial axis. By appropriately arranging the positions controlled by the holding device in the individual method steps, the movement requirement of the holding device can be reduced to two dimensions, which reduces the complexity of the method and the device used to carry out the method, thus leading to lower acquisition and operating costs.

[0046] In a preferred embodiment of the method according to the invention, the data processing system comprises a user interface, and the method comprises the additional method step: h) selecting at least one receiving element of the holding device by a user, wherein the pipette tips held on the selected receiving elements are discarded as scrap as a result of the selection, regardless of the acquired first and second image data in step f). Step h) is performed before any of steps a) to f).

[0047] The provision of a user interface that allows a user to manually select at least one receiving element of the holding device or to deselect the pipette tips held on this or these receiving elements offers the advantage that the deselected pipette tips can be treated as rejects in step f) of the method according to the invention - regardless of the image data acquired in step c) and / or step d). This can be advantageous, for example, if it is already known from a process preceding the method according to the invention that certain positions in the first matrix arrangement contain defective pipette tips. Without wishing to be limited to this explanation, it is assumed that the injection molding of individual reject-producing cavities cannot simply be stopped, since otherwise the thermal balance of the injection molding tool would be severely disrupted.Manual selection by the user thus represents a second safety instrument that ensures that the pipette tips in question are not dispensed into the second carrier.

[0048] In a preferred embodiment of the method according to the invention, step d) also includes, in particular, a surface inspection of the pipette tips to be tested to detect deviations of the pipette tip surfaces from a predefined standard. For this purpose, the second image capture device, the optionally present third image capture device, and / or one or more additional image capture devices, whose respective optical axes are aligned transversely to the longitudinal axis of the pipette tips held in the holding device and to the partial segments of the pipette tip surface facing the respective image capture device, can be used.

[0049] The object is further achieved by a device for checking pipette tips each extending along a longitudinal axis, which device is designed in particular to carry out the method for checking pipette tips described herein.

[0050] In particular, the object is achieved by a device comprising a receiving position designed to provide a first carrier containing pipette tips, and a holding device for receiving pipette tips from the first carrier provided at the receiving position. For this purpose, the holding device comprises a plurality of receiving elements, each of which is designed to receive a pipette tip. The device according to the invention further comprises a first image capture device for capturing first image data of the respective pipette tip outlet openings of the pipette tips received by the holding device, and a second image capture device for capturing second image data of the pipette tips held in the holding device. Furthermore, a data processing system is provided, which is connected in a signal-conducting manner to the first image capture device, the second image capture device, and the holding device.Acceptability limits for the first and / or second image data are predefined, i.e. stored, in the data processing system. The device according to the invention further comprises a waste container designed to receive pipette tips ejected by the holding device, as well as a dispensing position on which a second carrier can be provided. The device according to the invention has means for aligning the optical axis of the first image capture device parallel to the respective longitudinal axis of the pipette tips held in the holding device and to the respective pipette tip outlet openings. These means are also designed to align the optical axis of the second image capture device transversely to the respective longitudinal axis of the pipette tips held in the holding device and to the partial segments of the respective pipette tip lateral surfaces of the held pipette tips facing the second image capture device.The holding device of the device according to the invention can be moved back and forth between the receiving position, the first image capture device, the second image capture device, the waste container and / or the discharge position.

[0051] In a first embodiment of the device according to the invention, it comprises a receiving position configured to provide a first carrier containing pipette tips in a first matrix arrangement of rows and columns, as well as a holding device for receiving a row or column of pipette tips from the first matrix arrangement of rows and columns provided at the receiving position. The holding device comprises a plurality of receiving elements arranged in a row, each of which is configured to receive a pipette tip. The longitudinal axes of the pipette tips held by the receiving elements lie essentially in a common plane.The device according to the invention further comprises a first image capture device for capturing first image data of the respective pipette tip outlet openings of the pipette tips held by the holding device, and a second image capture device for capturing second image data of the pipette tips held in the holding device. The device according to the invention further comprises a data processing system that is signal-conductingly connected to the first image capture device, the second image capture device, and the holding device. Acceptance limits for the first and / or second image data are predefined, i.e., stored, in the data processing system.The device according to the invention further comprises a waste container designed to receive pipette tips ejected by the holding device, as well as a dispensing position on which a second carrier with a plurality of holes in a second matrix arrangement of rows and columns can be provided. The holes of the second carrier are suitable for holding the pipette tips. The device according to the invention has means for aligning the optical axis of the first image capture device parallel to the respective longitudinal axis of the pipette tips held in the holding device and to the respective pipette tip outlet openings.These means are also designed to align the optical axis of the second image capture device substantially perpendicular to the plane defined by the supported pipette tips and to the partial segments of the respective pipette tip lateral surfaces of the supported pipette tips facing the second image capture device. The holding device of the device according to the invention is movable back and forth between the receiving position, the first image capture device, the second image capture device, the waste container, and / or the dispensing position and is designed to successively fill the respective rows or columns of holes in the second carrier with pipette tips, without leaving one or more empty holes between two dispensed pipette tips.

[0052] Preferably, the receiving position and / or the delivery position of the device according to the invention according to the first embodiment is each designed to provide at least one rack.

[0053] In a second embodiment of the device according to the invention, the pipette tips are arranged in a circular arrangement in the first carrier. The arrangement of the receiving elements of the holding device corresponds to the circular arrangement of the pipette tips in the first carrier. The circular arrangement is, in particular, the tool arrangement of an injection molding machine located upstream of the device according to the invention.

[0054] In a preferred development of the second embodiment of the device according to the invention, the holding device has means for rotating the holding device about its axis of rotation.

[0055] In a preferred development of the second embodiment of the device according to the invention, the holding device comprises an illumination device fastened to the holding device, which divides the circular arrangement of pipette tips into two halves. The illumination device has two plane-parallel light-emitting surfaces for emitting light in opposite directions. Alternatively, it is conceivable for the holding device to comprise an illumination device fastened to the holding device and arranged in the center of the circular arrangement of pipette tips, for emitting light in the direction of the second image capture device. In this alternative, it is particularly advantageous if the illumination device is designed in the form of a light bulb or cylindrical with a circumferential light-emitting surface, since such an illumination device emits the light evenly.

[0056] The means for aligning the optical axes of the two image capture devices, i.e., the first image capture device and the second image capture device, as well as, if applicable, the third image capture device or the further image capture device for capturing the second image data, and the pipette tips held in the holding device, are, for example, a movement device controllable by the data processing system for the controlled motorized movement of the holding device in the direction of an X, Y, and Z spatial axis. For the reasons already mentioned in the method according to the invention, the holding device is preferably movable by the movement device only in the direction of an X and Y spatial axis.

[0057] With the aid of the device according to the invention, each pipette tip can be individually rotated around its rotation axis, i.e., its longitudinal axis. Only one camera is required to check the concentricity of the pipette tips, as explained in more detail below. This saves costs. Furthermore, the individual inspection of each pipette tip solves the problem of defective pipette tips ending up in the packaging container, resulting in the disposal of already packaged, fully filled pipette tip holders, or the costly replacement of defective pipettes with faulty ones. Such pipette tip holders are also known as "racks." Instead, defective pipette tips can be sorted out in advance, for example, by the device ejecting them into a container intended for rejects.Thus, only pipette tips that meet the predefined quality requirements in each individual case are transferred into packaging containers by the device.

[0058] In a preferred embodiment, the data processing system of the device according to the invention is signal-conductingly connected to an injection molding system upstream of the device according to the invention, which produces pipette tips in multiple cavities in an injection molding tool. The pipette tips removed from the cavities of the injection molding tool can be traceably transferred into the first matrix arrangement of pipette tips described here. In other words, it is possible to track which cavity of an injection molding tool a pipette tip at a specific position in the first matrix arrangement originates from. By constantly monitoring the quality of each individual pipette tip using the method according to the invention,The device according to the invention allows the data processing system of the device according to the invention to automatically determine which cavity is causing problems and subsequently deselect the affected cavity or cavities. As previously described, the pipette tips originating from a deselected cavity are treated as rejects – regardless of the image data acquired in step c) or step d) of the method according to the invention – and are never transferred to the second carrier in step g) of the method according to the invention.

[0059] In a preferred embodiment, the device according to the invention further comprises a measuring device for detecting the entry of the respective pipette tips, in particular the respective pipette tip outlet openings, into the optical axis of the first image capture device. The measuring device is connected to the first image capture device in a signal-conducting manner and is designed to trigger the acquisition of the first image data by the first image capture device. The measuring device for detecting the entry of the respective pipette tips into the optical axis of the first image capture device is preferably a light barrier.

[0060] Such a measuring device for triggering image acquisition has the advantage that it can accelerate the acquisition of the first image data.

[0061] In a preferred embodiment of the device according to the invention, the holding device comprises means for rotating the pipette tips held in the holding device about their longitudinal axis. The means for rotating the pipette tips are designed to rotate the pipette tips from a first position to a second position by a rotation angle α of at least substantially 90°. Preferably, the rotation angle α between the first position and the second position of the pipette tips is between substantially 90° and substantially 180°. Particularly preferably, the rotation angle α between the first position and the second position of the pipette tips is substantially 180°.

[0062] Preferably, the means for rotating the pipette tips held in the holding device comprise a gear on each receiving element. The gears of adjacent receiving elements mesh with each other, forming a gear assembly, and are rotatable by a rotary drive. The rotary drive is preferably arranged at one end of the gear assembly. This allows the holding device to be designed to be particularly compact and space-saving.

[0063] Alternatively, the means for rotating the pipette tips held in the holding device comprise a gear on each receiving element, with two adjacent gears being operatively connected to one another via an intermediate gear, forming a gear assembly. In this case, at least one of the gears or one of the intermediate gears of the gear assembly is rotatable by a rotary drive. As a result, the entire gear assembly is rotatable.

[0064] Alternatively, the gears of adjacent receiving elements arranged on a receiving element may not mesh. In this case, the gears are rotatable via a common rack and pinion drive or a common toothed belt. This allows all gears, and thus all receiving elements, to rotate in the same direction via the rack and pinion drive or toothed belt.

[0065] When using a toothed belt, it is advantageous to provide support means to ensure the operative connection between the gears and the toothed belt. The support means prevent the toothed belt from lifting off the gears and thus ensure uninterrupted and reliable drive of the respective gears. It is particularly preferred to arrange the support means in the area of ​​each contact point between the gears and the toothed belt.

[0066] Alternatively, the means for rotating the pipette tips held in the holding device comprise an individual drive, for example an electric motor, on each receiving element. Thus, each receiving element can be rotated independently of the remaining receiving elements of the holding device by its individual drive.

[0067] Alternatively, the means for rotating the pipette tips held in the holding device comprise a disk on each receiving element, which disk is arranged in a rotationally fixed manner in the circumferential direction of the respective receiving element. A rod drive is attached to each of the disks eccentrically relative to the longitudinal axis of the respective receiving element. The rod drive converts a reciprocating movement of a drive rod into a rotational movement of the receiving elements.

[0068] In a preferred embodiment of the device according to the invention, the means for rotating the pipette tips held in the holding device are designed to rotate the pipette tips into intermediate positions between the first position and the second position. In particular, the means for rotating the pipette tips held in the holding device are designed to rotate the pipette tips into one to four intermediate positions between the first position and the second position.

[0069] Preferably, the intermediate positions are evenly distributed between the first position and the second position, which allows a particularly reliable check of the concentricity of the respective pipette tips.

[0070] In a preferred development of the first embodiment of the device according to the invention, the number of receiving elements of the holding device corresponds to the number of pipette tips provided in a row or column of the first matrix arrangement.

[0071] By coordinating the number of receiving elements and the number of elements, ie pipette tips, of a row and / or column of the first matrix arrangement, the device according to the invention is designed particularly suitable for efficiently carrying out the method according to the invention, since the holding device in step b) of the method according to the invention can receive an entire row or column from the first matrix arrangement and feed it to the image capture devices.

[0072] The holding device preferably comprises at least five, preferably at least ten and even better at least fifteen receiving elements, since the advantages of the method according to the invention, in particular with regard to its efficiency and speed, increase further with an increasing number of pipette tips tested simultaneously.

[0073] In a preferred embodiment of the device according to the invention, the receiving elements each have a coupling attachment with a vacuum connection for holding the pipette tips on the receiving elements of the holding device by applying negative pressure. The coupling attachments are each designed such that they can be inserted into the plug-on end of a pipette tip opposite the pipette tip outlet opening. After applying negative pressure to the pipette tip, a substantially positive fit and thus a certain degree of tightness is established between the coupling connection and the pipette tip.

[0074] Such a design of the holding elements has the advantage that the pipette tips are reliably held and can be easily ejected again by releasing the negative pressure in the held pipette tips. A separate ejection device for ejecting the pipette tips from the holding elements can preferably be dispensed with.

[0075] Preferably, the receiving elements are conically shaped, which facilitates the insertion of the receiving elements into the plug-on end of the pipette tips, increases the tightness between the receiving element and the pipette tip, and also achieves a certain frictional press fit between the coupling attachment and the coupling area of ​​the pipette tip arranged near the plug-on end, which ensures particularly secure holding of the pipette tips on the respective receiving elements.

[0076] In a preferred embodiment, the device according to the invention comprises an illumination device that is fixedly arranged relative to the second image capture device. The illumination device is designed to emit light toward the second image capture device in the direction opposite to the optical axis of the second image capture device. This allows the contrast between the pipette tips and the background formed by the illumination device to be increased and the acquisition of the second image data by the second image capture device to be improved, as described above.

[0077] In a preferred embodiment, the data processing system of the device according to the invention comprises a user interface designed for the user to select at least one receiving element of the holding device. Following this selection, the pipette tips held on the selected receiving elements can be discarded as rejects, regardless of the acquired first and second image data. As already described above, this prevents pipette tips that were already identified as defective prior to the method according to the invention from being dispensed into the second carrier.

[0078] In a preferred development of the first embodiment of the device according to the invention, the receiving elements of the holding device are designed to be movable relative to one another. This allows their position relative to one another to be adapted to the first matrix arrangement and / or the second matrix arrangement of pipette tips, whereby the device according to the invention is variable and flexibly adaptable to different needs, i.e., different first and / or second matrix arrangements.

[0079] The object is further achieved by an injection molding system for producing and packaging pipette tips, wherein the injection molding system according to the invention comprises at least one device according to the invention for checking pipette tips.

[0080] Further advantages, features, and details of the invention are explained in more detail below with reference to the drawings, in which identical or similar elements are generally provided with the same reference numerals. They show: Fig. 1: Flow diagram of a variant of the method for checking pipette tips; Fig. 2a: Schematic representation of a first matrix arrangement of pipette tips in step a) of the Fig. 1 shown method; Fig. 2b: Schematic representation of the matrix arrangement of pipette tips from Fig. 2a after step b) of the Fig. 1 Fig. 2c: Schematic representation of a carrier with holes arranged in a second matrix arrangement for receiving pipette tips according to step g) of the method described in Fig. 1 shown method; Fig. 2d: Schematic representation of the first matrix arrangement of pipette tips from Fig. 2b after repeating step b) of the Fig. 1process shown; Fig. 2e: Schematic representation of the carrier from Fig. 2c after repeating step g) of the Fig. 1 illustrated method; Fig. 3a: A holding device with a plurality of receiving elements for receiving pipette tips in a longitudinal section; Fig. 3b: An end view of the holding device from Fig. 3a ; Fig. 3c: A section of the Fig. 3ashown holding device without pipette tips; Fig. 4: Schematic representation of various embodiments of the means for rotating the pipette tips held in the holding device; Fig. 5: Perspective view of an arrangement comprising a holding device and a first image capture device; Fig. 6: Perspective view of an arrangement comprising a holding device and a second image capture device; Fig. 7: Perspective view of a variant of the device for checking pipette tips; Fig. 8: Schematic representation of a carrier for providing pipette tips in a plurality of circular arrangements of pipette tips; Fig. 9a: A holding device with a plurality of circularly arranged receiving elements for receiving pipette tips in a side view; Fig. 9b: Longitudinal section through the holding device from Fig. 9a along line BB in Fig. 9a ; Fig. 9c: Bottom view of the holding device from Fig. 9a ; Fig. 10a: A further embodiment of a holding device with a plurality of circularly arranged receiving elements for receiving pipette tips in a side view; Fig. 10b: Longitudinal section through the holding device from Fig. 10a along line CC in Fig. 10a ; Fig. 11a: Perspective view of an arrangement comprising a holding device and a second image capture device; Fig. 11b: The holding device of Fig. 11a from the perspective of the second image capture device in Fig. 11a ; Fig. 12a: Perspective view of an arrangement comprising a holding device, a second image capture device and a third image capture device; Fig. 12b: Schematic representation of the beam path of the two optical axes from Figure 12aby the circular arrangement of the pipette tips held in the holding device; Fig. 13a: Side view of an arrangement comprising a holding device with an illumination device attached thereto and a second image capture device; Fig. 13b: Perspective view of the arrangement from Fig. 13a .

[0081] Figure 1 shows a schematic flow diagram of a variant of the inventive method for checking pipette tips according to the first embodiment. The method comprises the provision of pipette tips in a first matrix arrangement M1 of rows and columns in method step a). The provided pipette tips are picked up in step b) by a holding device 10 from the first matrix arrangement M1 of pipette tips, as will be described in more detail in the Figure 2a , 2b , 2dThe pipette tips picked up in step b) are fed in step c) to a first image capture device 30 for capturing first image data of the pipette tips, as will be described in detail below. Figure 5 Subsequently, in step d), the pipette tips held on the holding device are fed to a second image acquisition device 40 for capturing second image data of the pipette tips, as will be described in detail below. Figure 6 After the first and second image data of the pipette tips have been acquired in steps c) and d), a data processing system 70 of the device with which the method according to the invention is carried out determines whether the first and / or second image data lie within predefined admissible limits or not. These admissible limits are stored in the data processing system 70. In Figure 1In the exemplary embodiment shown, the evaluation of the first and / or second image data in step e) revealed that some of the pipette tips tested in step c) and step d) were outside the predefined acceptance limits. Subsequently, in step f), the holding device 10 is moved over an opening of a waste container 50, and the defective pipette tips are ejected into the waste container 50. Finally, those pipette tips whose first and second image data determined in step e) are within the predefined acceptance limits are dispensed into a second carrier having a plurality of holes suitable for holding the dispensed pipette tips and arranged in the second carrier in a second matrix arrangement M2 of rows and columns, as will be described in more detail in connection with the Figure 2c and 2eAlternatively, it is possible that all the pipette tips collected in step b) are within the predefined acceptance limits, as indicated by the dashed line in Figure 1 The holding device 10 is attached to a movement device 60 for motorized movement of the holding device 10, which movement device 60 moves the holding device 10 from and to the individual stations of process steps a) to g).

[0082] Figure 2ashows a schematic plan view of a first carrier 20 with a plurality of holes 22 for holding pipette tips 1, which holes 22 are arranged in a first matrix arrangement M1 in the first carrier 20. In the embodiment shown, each of the holes 22 in the first carrier 20 holds a pipette tip 1, so that the first carrier 20 provides a total of one hundred and five pipette tips 1. The first matrix arrangement M1 thus consists of fifteen columns AO and seven rows of holes 22. For example, the Figure 2a shown, first carrier 20 around the perforated plate of a rack for pipette tips. Figure 2a The situation shown is only a possible starting situation of step a) of the Figure 1, ie a starting situation in which a first carrier 20 completely filled with pipette tips 1 is provided in step a) of the inventive method. However, it is also conceivable according to the invention that the first carrier 20 provided in step a) of the inventive method is not or no longer completely filled with pipette tips 1, as will be explained below. Figure 2c described, and / or the first matrix arrangement has one or more free spaces between two adjacent pipette tips 1, 1'.

[0083] Figure 2b shows a schematic plan view of the Figure 2a shown first carrier 20, after in step b) of the Figure 1illustrated method, a complete column of pipette tips 1 was picked up from the first matrix arrangement M1 by a holding device (not shown), wherein the complete column in the illustrated embodiment comprises the positions A1 to A7 of the first carrier 20.

[0084] Figure 2c shows a schematic plan view of a second carrier 20' with a plurality of holes 22 for holding pipette tips 1, which holes 22 are arranged in a second matrix arrangement M2 in the second carrier 20'. Figure 2c The second support 20' shown corresponds in terms of the number and arrangement of the holes 22 to the support from Figure 2a, ie that the first matrix arrangement M1 and the second matrix arrangement M2 are identical in this variant of the inventive method for checking pipette tips 1. However, it is also conceivable according to the invention that the first matrix arrangement M1 and the second matrix arrangement M2 differ from each other, in particular with regard to the number of rows and columns and / or with regard to the distance of the holes 22 in the carriers 20, 20' relative to each other, which holes 22 define the respective matrix arrangement. In the Figure 2c The holes 22 on the positions A1 to A5 of the second carrier 20' were made in step g) of the Figure 1 method shown, each filled with a pipette tip 1, whereas the two remaining holes 22 of column A, ie positions A6 and A7, remained unoccupied in step g). Figure 2c The situation described arises from the Figure 2bsituation described, by the fact that step e) of the Figure 1 The method described in [ ] revealed that the first and / or second image data acquired in steps c) and d) of two of the seven pipette tips acquired in step b) did not lie within predefined acceptance limits (not shown). Subsequently, these two pipette tips 1 determined in step e) were used in step f) of the method described in Figure 1According to the method shown, the five remaining pipette tips 1, whose first and second image data determined in step e) lie within the predefined admissible limits, were dispensed into the second carrier 20' by the holding device in such a way that the holes 22 with the positions A1 to A5 of column A of the second carrier 20' were filled one after the other, without one or more empty holes 22 remaining between two dispensed pipette tips 1.

[0085] Figure 2d shows a schematic plan view of the Figure 2b shown first carrier 20, after in a further step b) of the Figure 1 In the method shown, a further complete column of pipette tips 1 was picked up from the first matrix arrangement M1 by a holding device (not shown), the complete column being in the Figure 2dillustrated embodiment comprises the positions B1 to B7 of the first carrier 20.

[0086] Figure 2e shows a schematic plan view of the second carrier 20' from Figure 2c , after in a further step g) of the Figure 1 The seven pipette tips 1, which - as shown in Figure 2d shown - were picked up by a holding device from column B of the first carrier 20, were dispensed into the second carrier 20' in such a way that the two empty holes 22, 22' with the positions A6 and A7 of column A of the second carrier 20' were first filled one after the other with one pipette tip 1 each and then the remaining five pipette tips 1 were dispensed into the holes 22 with the positions B1 to B6 of column B of the second carrier 20', without one or more empty holes 22 remaining between two dispensed pipette tips 1. The steps b) to g) of the Figure 1The method shown can be repeated as often as desired, in particular until all holes 22 of the second carrier 20' have been filled with checked pipette tips 1, in which case any pipette tips remaining in the holding device are dispensed into a further carrier 20" having a plurality of holes 22 in a second matrix arrangement M2 of rows and columns, which holes 22 are suitable for holding the dispensed pipette tips 1.

[0087] Figure 3ashows a longitudinal section through a holding device 10 for use in a method or device according to the first embodiment. The holding device 10 has fifteen receiving elements 11, each of which holds a pipette tip 1. The receiving elements 11 shown in this embodiment of the holding device 10 each have a conically shaped coupling attachment 18, which is fluidly connected to a vacuum connection 19. The pipette tips 1 are held on the receiving elements 11 of the holding device 10 by applying negative pressure to the respective pipette tip cavity. The holding device 10 further comprises means 13 for rotating the pipette tips 1 held in the holding device 10 on the receiving elements 11 about their longitudinal axis L.The means 13 for rotating the held pipette tips 1 about their longitudinal axis L are each assigned to a receiving element 11 and, in the illustrated embodiment, comprise a gear 14 on each receiving element 11. In the illustrated embodiment, the gears 14 mesh with one another and are rotatable by a common rotary drive.

[0088] By means of the illustrated means 13, the pipette tips 1 can each be rotated from a first position to a second position by a rotation angle of at least 90°. Furthermore, means 12 for aligning the pipette tips 1 held in the holding device 10 are attached to the holding device 10. This means 12 is part of a movement device 60—not visible in the illustration—for motor-driven movement of the holding device 10 in the direction of an X, Y, and Z spatial axis. Such a movement device is, for example, an industrial robot, which is known per se to those skilled in the art.

[0089] Figure 3b shows a front view of the holding device 10 from Figure 3a . From this view, it is particularly evident that all the receiving elements 11 are arranged in a row. Each pipette tip 1 is held at its plug-on end 4 on a receiving element 11, which plug-on end 4 is located in the longitudinal direction L at the end opposite its pipette tip outlet opening 2. The pipette tip surface 3 represents the area between the plug-on end 4 and the outlet opening 2 of a pipette tip 1. The longitudinal axes L of the pipette tips 1 held by the receiving elements 11 lie essentially in a common plane E. The pipette tips 1 arranged in a row are rotated by at least one drive 13 through an angle of rotation. The individual pipette tips 1 are connected to one another by a mechanism, as described below in Figure 4will be described in more detail using several conceivable examples.

[0090] Figure 3c shows the Figure 3a shown holding device 10 in a detailed view and without pipette tips. From the Figure 3c In the view shown, it is particularly evident that the longitudinal axes L, L' of two adjacent receiving elements 11, 11' run parallel and that the receiving elements 11, 11' are each connected in a rotationally fixed manner to a crank 111, 111'. A gear 14, 14' is in turn arranged on each of the cranks 111, 111', which gears 14, 14' mesh with one another and are thus operatively connected to one another. The cranks 111, 111' are each mounted by a plurality of bearings 112, 112' and sealed by means of a seal 113, 113'. The receiving elements 11, 11' each have a conically shaped coupling projection 18, 18', which is fluidly connected to a vacuum connection 19, 19'.

[0091] In Figure 4Further conceivable embodiments of the means 13 for rotating the pipette tips (not shown) held on the receiving elements of a holding device about their longitudinal axis L are shown schematically, in each case from a view in the direction of the longitudinal axis L of the pipette tips 1. Figure 4a shows five gear wheels 14, 14', which do not mesh with one another and are movable by a common rack and pinion drive 17, i.e. are rotatable about their respective longitudinal axis L. A gear wheel 14, 14' is arranged on each receiving element (not shown for reasons of clarity). By moving the rack and pinion drive 17 in the direction of the Figure 4a According to the arrow shown above the rack and pinion drive 17, all gears 14, 14' - and thus also all pipette tips - can be rotated in the same direction, as indicated by the arrows in the gears 14, 14'. Figure 4bshows an embodiment of the means 13 for rotating the pipette tips 1, in which a gear 14 is arranged on each of the five receiving elements. Between each two adjacent gears 14, 14', an intermediate gear 141 is arranged, which is operatively connected to the two gears 14, 14'. The five gears 14 shown and the four intermediate gears 141 form a gear assembly 15. At least one of the gears 14, 14' and / or at least one of the intermediate gears 141 of the gear assembly 15 is rotatable by a rotary drive 16, for example, an electric drive, pneumatic cylinder, or a lifting magnet. In this embodiment, all gears 14, 14' - and thus also all pipette tips - are rotatable in the same direction, as indicated by the arrows in the gears 14, 14'. Figure 4cAn embodiment is shown in which a gear 14 is arranged on each receiving element (not shown). Two adjacent gears 14, 14' mesh with each other to form a gear assembly 15. The gear assembly 15 is driven by a rotary drive 16 arranged at the right outer end of the gear assembly 15 in the illustration. This embodiment results in an alternating direction of rotation for the pipette tips, as indicated by the arrows in Figure 4c This is not important for the analysis. In the Figure 4dIn the variant shown, each of the five receiving elements 11 is assigned an individual drive 80, for example an electric drive, pneumatic cylinder, or a lifting magnet. The receiving elements 11 are not operatively connected to one another. As can be seen from the direction of the arrows shown, each receiving element 11 can be rotated independently of the remaining receiving elements 11 of the holding device (not shown). Figure 4e In the embodiment shown, each receiving element (not shown) comprises a disk 91, which is arranged in the circumferential direction U of the receiving elements in a rotationally fixed manner on the receiving elements. Eccentrically attached to the disks 91 is a rod drive 90 for converting a reciprocating movement of a drive rod 92 into a rotary movement of the disks 91 and thus of the receiving elements and the pipette tips. In the embodiment shown in Figure 4fIn the variant of the means 13 shown, a gear 14 is arranged on each receiving element. The gears 14 do not mesh with each other and are rotatable by a common toothed belt 142. At the points where the toothed belt 142 is not deflected by the outermost gears 14 in the illustration, support means 143 are also provided to ensure the operative connection between the gears 14 and the toothed belt 142. The six support means 143 shown prevent the toothed belt 142 from becoming detached from the gears 14 and the drive of the receiving elements from being interrupted.

[0092] Figure 5shows an arrangement comprising a holding device 10 and a first image capture device 30 in a perspective view. The pipette tip outlet openings 2 of the pipette tips 1 held in the holding device 10 are moved past the first image capture device 30 by means of a movement device 60 such that the optical axis OA1 of the first image capture device 30 is aligned parallel to the respective longitudinal axis L of the pipette tips 1 held on the receiving elements 11 and to the respective pipette tip outlet opening 2 during the acquisition of the first image data. In the case of the Figure 5In the arrangement shown, relating to the first embodiment of the device according to the invention, the movement of the holding device 10 is effected by the movement device 60 in the direction of the plane E spanned by the held pipette tips 1 and substantially perpendicular to and through the optical axis OA1 of the first image capture device 30, wherein the pipette tips 1 each guided through the optical axis OA1 of the first image capture device 30 are each moved past the first image capture device 30 substantially in one image plane, i.e. each at the same distance from the first image capture device 30.If a holding device is used on which the receiving elements 11 are arranged in a circle, the movement of the holding device 10 by the movement device 60 takes place such that the held pipette tips 1 are moved one after the other essentially perpendicular to and through the optical axis OA1 of the first image capture device 30, wherein the pipette tips 1 each passed through the optical axis OA1 of the first image capture device 30 are each moved past the first image capture device 30 at essentially the same distance. In both embodiments, a measuring device 31 in the form of a light barrier can also be provided, which detects the entry of the respective pipette tip outlet openings 2 into the optical axis OA1 of the first image capture device 30.The measuring device 31 is connected in a signal-conducting manner to the first image acquisition device 30 (not shown) and triggers the acquisition of the first image data by the first image acquisition device 30 as soon as the light barrier is interrupted by a pipette tip 1.

[0093] Figure 6shows a perspective view of an arrangement comprising a holding device 10 and a second image capture device 40, as it is present during the acquisition of the second image data in step d) of the inventive method according to the first embodiment. The optical axis OA2 of the second image capture device 40 is aligned substantially perpendicular to the plane E defined by the held pipette tips 1, wherein this plane E lies substantially in an image plane of the second image capture device 40. The second image data of the respective subsegments of the pipette tip lateral surfaces 3, which face the second image capture device 40, can thus be acquired simultaneously.By rotating the pipette tips 1 held in the holding device 10 from a starting position by a rotation angle of 90° to an end position, a further partial segment of the pipette tip surface 3 can be detected, wherein the concentricity of the pipette tips can be checked from the image data obtained in the starting position and the end position (not shown).

[0094] Figure 7shows a variant of a device 100 for checking pipette tips 1 according to the first embodiment, in a perspective view. The device 100 comprises a receiving position 101, which is designed to provide a first rack 21 containing pipette tips in a first matrix arrangement M1, wherein the racks 21 in the illustrated embodiment are each arranged on a workpiece carrier 23. The workpiece carriers 23 can be moved to the receiving position 101 by a transport device, for example a conveyor belt 103. The device 100 further has a holding device 10 for receiving a complete row or complete column of pipette tips 1 from the first rack 20 provided at the receiving position 101. The holding device 10 comprises a plurality of receiving elements 11 arranged in a row, each of which is designed to receive a pipette tip 1.With a first matrix arrangement M1 of the first rack of, for example, eight rows and twelve columns, the holding device thus has at least eight receiving elements 11 arranged in a row in order to be able to accommodate a complete column of eight pipette tips from one of the twelve columns of the first rack. However, according to the invention, it is conceivable for the holding device to have twelve receiving elements 11 arranged in a row, so that either a complete column of eight pipette tips from one of the twelve columns of the first rack can be accommodated, or a complete row of twelve pipette tips from one of the eight rows of the first rack can be accommodated.The device 100 further comprises a first image capture device 30 for capturing first image data of the respective pipette tip outlet openings 2 and a second image capture device 40 for capturing second image data of the pipette tips 1 held in the holding device 10. Furthermore, a measuring device 31 is provided for detecting the passage of the pipette tips through the optical axis of the first image capture device. The device 100 further comprises an illumination device 41 arranged fixedly relative to the second image capture device 40, which is designed to emit light onto the second image capture device 40 in the direction opposite to the optical axis of the second image capture device 40.A data processing system (not shown), in which admissibility limits for the first and / or second image data are predefined, is signal-conductingly connected to at least the first image capture device 30, the second image capture device 40, and the holding device 10, so that pipette tips 1 whose first or second image data lie outside the admissibility limits predefined in the data processing system can be ejected from their respective receiving element 11 into a waste container (not shown). The device 100 further comprises a dispensing position 102, on which, in the embodiment shown, a second rack 21' is provided on a further workpiece carrier 23. The second rack 21' has a plurality of holes in a second matrix arrangement M2 of rows and columns, each hole being designed to hold a pipette tip 1.In the illustrated embodiment, the first rack 21 and the second rack 21' are identical. The device 100 further comprises means for aligning the pipette tips 1 held in the holding device 10 relative to the first image capture device 30 and the second image capture device 40, which in the illustrated embodiment are implemented by a movement device 60, an industrial robot. The movement device 60 is designed to move the holding device 10 between the receiving position 101, the first image capture device 30, the second image capture device 40, the in . Figure 7 waste container (not shown) and the delivery position 102.

[0095] Figure 8shows a carrier 20 for providing pipette tips 1 in a plurality of circular arrangements K in a schematic representation. The arrangement of the pipette tips 1 in the carrier 20 preferably corresponds to the arrangement of the pipette tips 1 in the cavities of the Figure 8 not shown injection molding tool from which they originate, so that the produced pipette tips can be easily transferred into the first carrier 20 after opening the injection molding tool while maintaining the arrangement present in the injection molding tool, the tool order. In the case of the Figure 8In the example shown, the first carrier 20 comprises eight circular arrangements K, each with eight receptacles for a pipette tip 1. In principle, injection molding tools with eight or a multiple of eight cavities (e.g., 16, 32, 64, 96, or 128) are preferably used for the production of pipette tips, although different numbers of cavities (e.g., 12, 20, etc.) are also feasible. Consequently, as explained above, the number of receptacles and their arrangement in the carrier can also vary, particularly depending on the injection molding tool used.

[0096] Figure 9a shows a side view of a holding device 10 with eight circularly arranged receiving elements 11 for receiving a pipette tip 1 each according to the second embodiment of the device according to the invention, as can be seen from the Figure 9c The bottom view shown in Figure 9cThe arrangement shown of eight pipette tips 1 which are evenly spaced apart from one another in the circumferential direction of the circular arrangement K corresponds to the circular arrangement K as shown in Figure 8 shown first carrier 20 is present. A longitudinal section through the holding device 10 along the line BB is shown in Figure 9b As can be seen therefrom, the receiving elements 11 each have a conically shaped coupling attachment 18, which is fluidly connected to an associated vacuum connection 19. The holding device 10 further has a rotation axis A extending in the direction of the pipette tips 1 received by the holding device 10. The rotation axis A of the holding device 10 thus runs essentially parallel to the longitudinal axes L of the pipette tips 1 held by the receiving elements 11 of the holding device 10.

[0097] Figure 10ashows a further embodiment of a holding device 10 with a plurality of circularly arranged receiving elements 11 for receiving pipette tips 1 in a side view. As can be seen from the Figure 10b shown longitudinal section through the holding device 10 along the line CC in Figure 10a As can be seen, the receiving elements 11 can each be equipped with a lifting function, whereby the pipette tips 1 can be placed and / or picked up in a controlled manner along their longitudinal axes L. This can, for example, eliminate the risk of a collision between pipette tips held in the holding device 10 and already present in the second carrier.

[0098] Figure 11ashows a perspective view of an arrangement comprising a holding device 10 and a second image capture device 40 according to the second embodiment of the device according to the invention. During the acquisition of the second image data of the eight pipette tips 1 held in the holding device 10, the optical axis OA2 of the second image capture device 40 is aligned transversely to the longitudinal axis L and toward the partial segments of the respective pipette tip surfaces 3 of these eight pipette tips 1 facing it. The holding device 10 is positioned in the beam path between the illumination device 41 and the second image capture device 40.

[0099] Figure 11b shows the holding device 10 from Figure 11a from the perspective of the second image capture device in Figure 11a in the direction of the illumination device 41. As can be seen from the illustration of the pipette tips 1 in the left half of Figure 11bwhich of the situation in Figure 11a corresponds, of the total of eight pipette tips 1 held in the holding device 10, the contours of only five pipette tips 1 are detectable by the second image capture device, since three pipette tips are covered by three of the detectable pipette tips 1. In order for the second image capture device to capture the second image data of all the pipette tips 1 held in the holding device 10, the holding device 10 can be rotated about its rotation axis A by a rotation angle β before capturing the second image data. The result of the rotation of the holding device 10 by a rotation angle β of approximately 15° is shown in the right half of Figure 11band shows that as a result of this rotation, the contours of all pipette tips 1 held in the holding device 10 can now be captured by the second image capture device. In the right half of Figure 11b Between the pipette tips 1 shown adjacent to each other in the beam path, in the area of ​​the respective recording elements on the left and right with respect to the respective longitudinal axis of the pipette tips, there is a gap which is no longer visible to the naked eye in this representation, but which can be reliably detected by the second image capture device.

[0100] Figure 12ashows a perspective view of an arrangement comprising a holding device 10, a second image capture device 40, and a third image capture device 43. The optical axes OA2 and OA3 of the second and third image capture devices 40, 43 are substantially perpendicular to one another and aligned with the partial segments of the respective pipette tip lateral surfaces facing the respective image capture devices 40, 43. The pipette tips 1 held by the holding device 10 are positioned between the second image capture device 40 and an illumination device 41, as well as between the third image capture device 43 and a further illumination device 41'. A schematic representation of the beam path through the pipette tips 1 held in the holding device 10 from Figure 12a is in Figure 12b As can be seen from Figure 12bAs can be seen, the contours of the first part of the pipette tips held in the holding device 10, i.e. the contours of the pipette tips marked with the reference symbol 1a, are completely detectable by the second image capture device, since the pipette tips marked with the reference symbol 1a are individually resolved in the beam path of the optical axis OA2 of the second image capture device. The contours of the second part of the pipette tips held in the holding device 10, i.e. the contours of the pipette tips marked with the reference symbol 1b, are completely detectable by the third image capture device, since the pipette tips marked with the reference symbol 1b are individually resolved in the beam path of the optical axis OA3 of the third image capture device. Analogous to the Figures 11a and 11bIn the exemplary embodiment described above, it may also be advantageous, depending on the arrangement, size and spacing of the held pipette tips, to rotate the holding device 10 about its axis of rotation by an angle of rotation β before acquiring the second image data in order to be able to capture the contours of the pipette tips 1a, 1b held in the holding device 10, preferably completely, by the second and third image capture devices 40, 43.

[0101] Figure 13ashows a side view of an arrangement comprising a holding device 10 with an illumination device 44 attached thereto and a second image capture device 40. The illumination device 44 has two plane-parallel light-emitting surfaces 44a, 44b and divides the circular arrangement of pipette tips 1 into two halves, K1 and K2. During the acquisition of the second image data, the optical axis OA2 of the second image capture device 40 is aligned perpendicular to the illumination device 44, specifically to the light-emitting surface 44a facing the second image capture device 40. During the acquisition of the second image data, the optical axis OA2 of the second image capture device is also aligned to the sub-segments of the respective pipette tip lateral surfaces 3 facing the second image capture device 40. Figure 13b shows a perspective view of the arrangement of Figure 13a, wherein the light emitting surface 44b facing away from the second image capture device 40 as well as the half K2 of the circular arrangement of pipette tips 1 facing away from the second image capture device 40 are shown. When using a single second image capture device 40, as in the embodiment according to Figure 13a and 13b, the second image data of those pipette tips 1 belonging to the half K1 facing the second image capture device 40 are first captured. The holding device 10 is then rotated by 180° in order to face the other half K2 of pipette tips 1, separated from the first half K1 by the illumination device 44, towards the second image capture device 40. Alternatively, when using a further image capture device for capturing the second image data 42 (not shown), it is possible to capture the second image data of the pipette tips 1 of both halves K1 and K2 simultaneously. For this purpose, the two image capture devices for capturing second image data 40, 42 are aligned in opposite directions with the holding device 10 positioned between the two image capture devices 40, 42.

Claims

1. A method of inspecting pipette tips (1) each extending along a longitudinal axis (L), the method comprising the following method steps: a) Providing pipette tips (1) arranged in a first carrier (20); b) Picking up pipette tips (1) from the first carrier (20) by a holding device (10) comprising a plurality of pick-up elements (11) for receiving one pipette tip (1) each; c) Acquiring first image data of the respective pipette tip outlet openings (2) of the pipette tips (1) picked up by the holding device (10) by a first image acquisition device (30); d) Acquiring second image data of the pipette tips (1) held in the holding device (10) by a second image acquisition device (40), the optical axis (OA2) of which is aligned during the acquisition of the second image data transversely to the respective longitudinal axis (L) of the pipette tips (1) held in the holding device (10) and onto the partial segments of the respective pipette tip jacket surfaces (3) of the held pipette tips (1) facing the second image acquisition device (40); e) Determining whether or not the first and / or second image data are within predefined allowable limits using a data processing system (70); f) Discarding those pipette tips (1) whose first and / or second image data determined in step e) lie outside the predefined allowable limits into a waste container (50) by the holding device (10); g) Dispensing those pipette tips (1) whose first and second image data determined in step e) lie within the predefined allowable limits into a second carrier (20'), in particular into a rack (21, 21'); wherein in method step d) the second image data of several of the pipette tips (1) held in the holding device (10), preferably of all pipette tips (1) held in the holding device (10), are acquired simultaneously.

2. The method according to claim 1, wherein: - the pipette tips (1) provided in step a) are arranged in the first carrier (20) in a first matrix arrangement (M1) of rows and columns, in particular in a first rack (21); - in step b) a row or column, preferably a complete row or complete column, of pipette tips (1) from the first matrix arrangement (M1), in particular from the first rack (21), is picked up by the holding device (10), wherein the pick-up elements (11) of the holding device (10) are arranged in a row, and wherein the longitudinal axes (L) of the pipette tips (1) held by the pick-up elements (11) lie substantially in a common plane (E); - in step c) the optical axis (OA1) of the first image acquisition device is aligned in the same direction, in particular parallel, to the respective longitudinal axis (L) of the pipette tips (1) held in the holding device (10) and onto the respective pipette tip outlet opening (2) during the acquisition of the first image data; - in step d) the optical axis (OA2) of the second image acquisition device (40) is aligned substantially perpendicular to the plane (E) defined by the held pipette tips (1) during the acquisition of the second image data, so that all pipette tips (1) held in the holding device (10) are arranged substantially in one image plane of the second image acquisition device (40), wherein the second image data of all pipette tips (1) held in the holding device (10) are acquired simultaneously; - in step g), the second carrier (20') has a plurality of holes (22) in a second matrix arrangement (M2) of rows and columns, the holes (22) being suitable for holding the dispensed pipette tips (1); and wherein the pipette tips (1) are dispensed in method step g) by the holding device (10) in such a way that the respective rows or columns of holes (22) of the second carrier (20') are filled up one after the other without leaving one or more empty holes (22, 22') between two dispensed pipette tips (1).

3. The method according to claim 1, wherein: - the pipette tips (1) provided in step a) are arranged in the first carrier (20) in at least one circular array (K), in particular in at least one circular array (K) of eight pipette tips (1) uniformly spaced from one another in the circumferential direction of the circular array (K); - in step b) a circular array (K), in particular a full circular array (K), of pipette tips (1) is picked up from the first carrier (20) by the holding device (10); - optionally, in step d), the holding device (10) is rotated about its axis of rotation (A) extending in the direction of the pipette tips (1) held by the holding device (10) by an angle of rotation (β) prior to the acquisition of the second image data in such a way that the contours of at least some, preferably all, of the pipette tips (1) held in the holding device (10), preferably completely, can be detected by the second image acquisition device (40).

4. The method according to claim 3, wherein in step d) the holding device (10) is rotated about its axis of rotation (A) running in the direction of the pipette tips (1) picked up by the holding device (10) during the acquisition of the second image data, in particular the holding device (10) performs at least three quarters of a rotation about its axis of rotation (A) during the acquisition of the second image data, and wherein optionally in step d) the pipette tips (1) picked up by the holding device (10) are each rotated about their longitudinal axis (L).

5. The method according to claim 3 or 4, wherein the second image data of the pipette tips (1) held in the holding device (10) are additionally acquired in step d) by a third image acquisition device (43), the optical axis (OA3) of which is aligned during the acquisition of the second image data substantially perpendicular to the optical axis (OA2) of the second image acquisition device (40) and onto the partial segments, facing the third image acquisition device (43), of the respective pipette tip jacket surfaces (3) of the picked-up pipette tips (1), wherein optionally in step d) the holding device (10) is rotated about its axis of rotation (A) extending in the direction of the pipette tips (1) picked up by the holding device (10) by an angle of rotation (β) prior to the acquisition of the second image data in such a way that the contours of a first part (1a) of the pipette tips (1) held in the holding device (10), preferably completely, can be detected by the second image detection device (40), and in that the contours of a second part (1b) of the pipette tips (1) held in the holding device (10) can be detected, preferably completely, by the third image detection device (43).

6. The method according to claim 3, wherein the optical axis (OA2) of the second image acquisition device (40) during the acquisition of the second image data in step d) is further aligned perpendicular to an illumination device (44) attached to the holding device (10) and dividing the circular array (K) of pipette tips (1) into two halves (K1, K2), said illumination device (44) having two substantially plane-parallel light emitting surfaces (44a, 44b) for emitting light in the direction of said second image acquisition device (40) and opposite to said direction, wherein, in step d) i. the second image data of one half (K1) of the pipette tips (1) are acquired and the holding device (10) is rotated by 180° about its axis of rotation (A) extending in the direction of the pipette tips (1) picked up by the holding device (10) before the second image data of the other half (K2) of the pipette tips (1) are acquired; or ii. a further image acquisition device (42) for acquiring second image data of the pipette tips (1) held in the holding device (10) is provided, the optical axis of which is aligned opposite to the optical axis (OA2) of the second image acquisition device (40), wherein the second image data of both halves (K1, K2) of the circular array (K) of pipette tips (1) are acquired simultaneously.

7. The method according to claim 4, wherein during the acquisition of the second image data in step d), the optical axis (OA2) of the second image acquisition device (40) is further aligned with an illumination device (45) attached to the holding device (10) and located at the center of the circular array (K) of pipette tips (1), which illumination device emits light toward the second image acquisition device (40) during the acquisition of the second image data in step d).

8. The method according to any one of the preceding claims, wherein the first image data in step c) is acquired when moving the pipette tips (1) held in the holding device (10) transversely to the optical axis (OA1) of the first image acquisition device (30) and through the optical axis (OA1) of the first image acquisition device (30) relative to each other, wherein the entry of the respective pipette tips (1), in particular of the respective pipette tip outlet openings (2), into the optical axis (OA1) of the first image acquisition device (30) is detected by a measuring device (31), in particular a light barrier (31), and triggers the acquisition of the first image data by the first image acquisition device (30), wherein preferably only the holding device (10) is moved and the first image acquisition device (30) remains stationary, wherein preferably the respective pipette tip outlet openings (2) of the pipette tips (1) held in the holding device (10) are guided past the first image acquisition device essentially in a single image plane of the first image acquisition device (30).

9. The method according to any one of the preceding claims, wherein step d) comprises the following method steps: i. Acquiring a first image of the pipette tips (1) held in the holding device (10), wherein the pipette tips (1) are each in a first position (P1); ii. Rotating the pipette tips (1) held in the holding device (10) about their longitudinal axis (L) by a predetermined angle of rotation (α) to a second position (P2); iii. Acquiring a second image of the pipette tips (1) held in the holding device (10), the pipette tips (1) each being in the second position (P2); wherein the angle of rotation (a) between the first position (P1) and the second position (P2) is at least substantially 90°, preferably between substantially 90° and substantially 180°, particularly preferably substantially 180°.

10. The method according to claim 9, wherein the pipette tips (1) for acquiring further images, preferably further one to four images, are rotated into a number of intermediate positions (P3, P4, P5, P6) corresponding to the number of further images, which intermediate positions (P3, P4, P5, P6) are located between the first position (P1) and the second position (P2) and are preferably evenly distributed between the first position (P1) and the second position (P2).

11. The method according to one of the preceding claims, wherein the pipette tips (1) are each held non-positively on the pick-up elements (11) of the holding device (10), preferably by applying negative pressure to the pipette tips (1).

12. The method according to any one of the preceding claims, wherein the data processing system (70) comprises a user interface (71), and the method additionally comprises a method step: h) selecting at least one pick-up element (11) of the holding device (10) by a user, wherein the pipette tips (1) held on the selected pick-up elements (11) are discarded as rejects as a result of the selection independently of the acquired first and second image data in step f); wherein step h) is performed prior to any of steps a) through f).

13. An apparatus (100) for inspecting pipette tips (1) each extending along a longitudinal axis (L), in particular adapted to carry out a method according to any one of the preceding claims, the apparatus (100) comprising: - A receiving position (101) configured to provide a first carrier (20) containing pipette tips (1); - A holding device (10) for picking up pipette tips (1) from the first carrier (20) provided at the receiving position (101), the holding device (10) comprising a plurality of pick-up elements (11), which pick-up elements (11) are configured for receiving one pipette tip (1) each; - A first image acquisition device (30) for acquiring first image data of the respective pipette tip outlet openings (2) of the pipette tips (1) picked up by the holding device (10); - A second image acquisition device (40) for acquiring second image data of the pipette tips (1) held in the holding device (10); - A data processing system (70) which is signal-conductively connected to the first image acquisition device (30), the second image acquisition device (40) and the holding device (10), and in which allowable limits for the first and / or second image data are predefined; - A waste container (50) configured to receive pipette tips (1) discarded by the holding device (10); - A dispensing position (102) on which a second carrier (20'), in particular a rack (20, 20'), can be provided; the apparatus (100) comprising means (12) for aligning the optical axis (OA1) of the first image acquisition device (30) parallel to the respective longitudinal axis (L) of the pipette tips (1) held in the holding device (10) and onto the respective pipette tip outlet openings (2), and for aligning the optical axis (OA2) of the second image acquisition device (40) transverse to the respective longitudinal axis (L) of the pipette tips (1) held in the holding device (10) and onto the partial segments of the respective pipette tip jacket surfaces (3) of the held pipette tips (1) facing the second image acquisition device (40), said holding device (10) being movable back and forth between said receiving position (101), said first image acquisition device (30), said second image acquisition device (40), said waste container (50) and / or said dispensing position (102).

14. The apparatus (100) according to claim 13, wherein - the pipette tips (1) are arranged in the first carrier (20) in a first matrix arrangement (M1) of rows and columns, in particular the first carrier (20) is a first rack (21); - the holding device (10) is configured to pick up a row or column of pipette tips (1) from the first matrix arrangement (M1) of rows and columns, in particular from the first rack (21), and the pick-up elements (11) of the holding device (10) are arranged in a row, the longitudinal axes (L) of the pipette tips (1) held by the pick-up elements (11) lying substantially in a common plane (E); - the second carrier (20'), in particular the rack (21, 21') has a plurality of holes (22) in a second matrix arrangement (M2) of rows and columns, which holes (22) are suitable for holding the pipette tips (1); - the means (12) for aligning the optical axis (OA2) of the second image acquisition device (40) are configured to align the optical axis (OA2) of the second image acquisition device (40) substantially perpendicular to the plane (E) defined by the held pipette tips (1); and - wherein the holding device (10) is adapted for successively filling the respective rows or columns of holes (22) of the second carrier (20') with pipette tips (1) without leaving one or more empty holes (22, 22') between two dispensed pipette tips (1, 1').

15. The apparatus (100) according to claim 13, wherein the pipette tips (1) are arranged in a circular array (K) in the first carrier (20), and wherein the arrangement of the pick-up elements (11) of the holding device (10) corresponds to the circular array (K) of the pipette tips (1) in the first carrier (20).

16. The apparatus (100) according to claim 15, wherein the holding device (10) comprises means (121) for rotating the holding device (10) about its axis of rotation (A) extending in the direction of the pipette tips (1) picked up by the holding device (10).

17. The apparatus (100) according to claim 15 or 16, wherein said holding device (10) comprises - an illumination device (44) fixed to the holding device (10) and dividing the circular array (K) of pipette tips (1) into two halves (K1, K2), the illumination device (44) having two plane-parallel light emitting surfaces (44a, 44b) for emitting light in opposite directions; or - an illumination device (45) fixed to the holding device (10) and arranged in the center of the circular array (K) of pipette tips (1), for emitting light in the direction of the second image acquisition device (40), the illumination device (45) being designed in particular in the form of a cylinder with a circumferential light emission surface (45a).

18. The apparatus (100) according to any one of claims 13 to 17, wherein the apparatus (100) further comprises a measuring device (31), in particular a light barrier (31), for detecting the entry of the respective pipette tips (1), in particular the respective pipette tip outlet openings (2), into the optical axis (OA1) of the first image acquisition device (30), which measuring device (31) is connected in a signal-conducting manner to the first image acquisition device (30) and is configured to trigger the acquisition of the first image data by the first image acquisition device (30).

19. The apparatus (100) according to any one of claims 13 to 18, wherein the holding device (10) comprises means (13) for rotating the pipette tips (1) held in the holding device (10) about their longitudinal axis (L), which means (13) are configured to rotate the pipette tips (1) from a first position (P1) to a second position (P2) through a rotation angle (a) of at least substantially 90°, preferably between substantially 90° and substantially 180°, particularly preferably of substantially 180°.

20. The apparatus (100) according to claim 19, wherein the means (13) for rotating the pipette tips (1) held in the holding device (10) comprise: - A gearwheel (14) on each pick-up element (11), which gearwheels (14) mesh to form a gear train (15) and are rotatable by a rotary drive (16) preferably located at one end of the gear train (15); or - a gearwheel (14) on each pick-up element (11), two adjacent gearwheels (14, 14') being operatively connected to one another via an intermediate gearwheel (141) to form a gear train (15), at least one of the gearwheels (14) and / or at least one of the intermediate gearwheels (141) of the gear train (15) being rotatable by a rotary drive (16); or - a gearwheel (14) on each pick-up element (11), which gearwheels (14) do not mesh and are rotatable by a common rack-and-pinion drive (17); or - a gearwheel (14) on each pick-up element (11), which gearwheels (14) do not mesh and are rotatable by a common toothed belt (142), preferably support means (143) being provided for ensuring the operative connection between the gearwheels (14) and the toothed belt (142); or - an individual drive (80), in particular an electric motor (80), on each pick-up element (11), wherein each pick-up element (11) is rotatable by the individual drive (80) independently of the remaining pick-up elements (11) of the holding device (10); or - a disc (91) on each pick-up element (11), which discs (91) are each arranged on the pick-up elements (11) in a rotationally fixed manner in the circumferential direction (U) of the pick-up elements (11) and on which discs (91) a rod drive (90) for converting a reciprocating movement of a drive rod (92) into a rotational movement of the pick-up elements (11) is eccentrically applied in each case.

21. The apparatus (100) according to any one of claims 13 to 20, wherein the means (13) for rotating the pipette tips (1) held in the holding device (10) are configured for rotating the pipette tips (1) into intermediate positions (P3, P4, P5, P6), which intermediate positions (P3, P4, P5, P6) lie between the first position (P1) and the second position (P2) and are preferably distributed uniformly between the first position (P1) and the second position (P2).

22. The apparatus (100) according to claim 14 or any one of claims 18 to 21, wherein the number of pick-up elements (11) of the holding device (10) corresponds to the number of pipette tips (1) provided in a row or column of the first matrix arrangement (M1), wherein the holding device (10) preferably comprises at least 5, preferably at least 10 and more preferably at least 15 pick-up elements (11).

23. The apparatus (100) according to any one of claims 13 to 22, wherein the pick-up elements (11) each comprise a coupling element (18), in particular of conical shape, which is or can be connected in a fluid-conducting manner to a vacuum connection (19) in order to hold the pipette tips (1) on the pick-up elements (11) of the holding device (10) by applying negative pressure.

24. The apparatus (100) according to claim 14 or any one of claims 18 to 23, wherein the pick-up elements (11) of the holding device (10) are configured to be movable with respect to each other so that their position with respect to each other can be adapted to the first matrix arrangement (M1) and / or the second matrix arrangement (M2) of pipette tips.

25. An injection molding machine (200) comprising at least one apparatus (100) for inspecting pipette tips (1) according to any one of claims 13 to 24.