SYSTEM FOR OPTICAL DETECTION OF THE FINGER REST OF A GLASS SYRINGE

Description

[0001] The invention relates to a system for optically detecting a finger rest of a glass syringe according to the preamble of claim 1 and to a method for optically detecting a finger rest of a glass syringe according to the preamble of claim 10.

[0002] In medicine, syringes are used, among other things, to administer medication. These syringes are usually delivered unfilled by the syringe manufacturer to the pharmaceutical manufacturer, who then takes care of filling, packaging, etc. However, the syringes can also be filled and, if necessary, packaged by the syringe manufacturer, so that they can be delivered to the pharmaceutical manufacturer as "pre-filled" and ready for use—i.e., filled and with a protected hollow needle or cannula.

[0003] These syringes are often made of transparent plastic or glass. The transparency of the syringe material allows the administering staff to directly visually inspect the contents, for example, for foreign matter, precipitates, discoloration, and fill level. Likewise, the transparency of the syringe body gives the patient confidence regarding the procedure being performed.

[0004] Due to its chemical resistance, glass is the preferred material for syringes. Glass's resistance to chemicals virtually completely prevents corrosion, which is common with plastics. This minimizes any contamination of the medication by the syringe material. The various glass materials are divided into different hydrolytic classes based on their hydrolytic resistance, i.e., the degree to which basic compounds can be extracted from the glass by exposure to water at 98°C. Borosilicate glasses, for example, are used to meet the requirements of the highest, first hydrolytic class.

[0005] The production of such glass syringes at a glass manufacturer, for example, usually proceeds as follows. First, a piece of a predetermined length is cut from a cylindrical glass tube, also called cutting to length, which essentially forms the cylindrical syringe body. A first, front end of the syringe body is heated and, by narrowing its diameter, deformed into a bore into which the hollow needle (cannula) can later be glued, for example. The syringe body itself retains its shape and diameter and roughly corresponds to the diameter of the plunger, which should be able to move longitudinally within the syringe body during use.

[0006] The second, rear end of the syringe body, which is diametrically opposite the bore, retains its diameter so that it can later accommodate the syringe plunger. By heating the material, this second, rear end of the syringe body is at least partially radially expanded so that a so-called finger rest can be formed here for handling the syringe. When handling the syringe, the user's index and ring fingers reach behind the finger rest from the side of the syringe body and the thumb presses the plunger into the syringe body in the opposite direction, whereby the syringe contents are dispensed from the syringe body via the hollow needle in the bore. This finger rest is usually cylindrical, closed in a ring shape, or interrupted in a cylindrical ring shape with two radially protruding sections.

[0007] Once the actual glass syringe body has been manufactured, it can optionally be labeled with something like a fill level scale. The hollow needle is then glued into the bore; it is also possible to place a Luer connection or a Luer-like connection on or into the bore. The glass syringe is then washed and sterilized to remove foreign bodies and impurities. The hollow needle is then sealed with a plastic cap, for example, to protect it from external influences. With the hollow needle pointing downwards, the syringe body is then filled from the other end and closed from this side with the plunger. The glass syringe is now ready for use and can be packaged.

[0008] This manufacturing process places very high demands on the quality of the glass syringe because its properties have a decisive influence on the subsequent filling steps and how it is used by the patient. Deviating dimensions of the glass syringe can lead to assembly errors or leaks, for example when gluing in the hollow needle or inserting the plunger. Wall thicknesses of the syringe body that are too thin, as well as scratches or cracks in the syringe body or finger rest, can lead to splintering and non-sterility of the glass syringe during production or use. A finger rest that is too thin can break off during use. These risks exist in particular because glass as a syringe material is optimized for its chemical resistance rather than mechanical stability.

[0009] If these defects are not detected before the next filling step, part of the glass syringe may chip off or the glass syringe may completely shatter, which could lead to production downtime due to glass parts in the production facilities. If this results in leaks, the sterility of the medication may be compromised. If the defects are only discovered by the user or patient before use, it is very likely that the patient will lose trust in the administering staff and that the user will lose trust in the supplier of the defective glass syringe, i.e. the pharmaceutical manufacturer. Both of these situations could lead to the patient changing doctors or the doctor or hospital changing pharmaceutical suppliers.Such incidents are particularly relevant for pharmaceutical manufacturers, as they can lead to a recall of the affected product and a loss of the corresponding product approval (good manufacturing practice). Therefore, pharmaceutical manufacturers and glass syringe manufacturers apply the highest possible quality standards to their glass syringes in order to rule out any defects with near certainty.

[0010] Syringe bodies are therefore usually inspected for both dimensional aspects, i.e. geometric characteristics, and cosmetic aspects. For a syringe body, dimensional aspects can include, for example, the diameter of the cylindrical syringe body, the diameter of the bore for attaching the hollow needle (cannula) using a Luer connection or Luer-like connection, the shoulder height of the syringe body in the longitudinal direction, the neck length of the syringe body in the longitudinal direction, the diameter of the plunger end, the length measurement of the syringe body as a whole in the longitudinal direction, the eccentricity of the syringe body or bore relative to the longitudinal axis, the flatness of the mouth of the finger rest end or the plunger end, etc. Cosmetic aspects can include contamination, foreign bodies, scratches, scars, cracks, chipped areas, inclusions or other customer-specific features.

[0011] Particularly in the case of the finger rest of the syringe body made of glass, dimensional defects may include deviations in the circular peripheral shape or the formation of the two radially projecting sections and deviating or insufficient thicknesses (thickness in the longitudinal direction) of the glass material, ie so-called sink marks, as well as cosmetic defects such as scratches, scars, cracks, inclusions and chipped areas.

[0012] The user may notice the dimensional defects both haptically and visually, as they impair handling. The finger rest may also break during use. Cosmetic defects can cause injury to the user, either directly or through the finger rest breaking off in whole or in part, or through the glass syringe breaking as a whole. Furthermore, contaminants may occur during production that adhere to the rest of the glass body or remain on or in it. This can be partially removed by the washing process, but not completely. Furthermore, contaminants, which are inorganic pollutants, are not affected by sterilization. If they are on the finger rest, they can enter the syringe body when the glass syringe is raised up with the tip downwards to fill it with its contents.

[0013] During production, cracks in the finger rest and sink marks in the finger rest are also a common cause of glass syringe breakage during the subsequent washing process or during filling. Therefore, the inspection of the finger rest of a glass syringe is particularly important in the manufacture of glass syringes.

[0014] Optical methods, such as camera technology, are generally known for quality control in production. These methods process signals that represent images (image processing). These optical methods are also used to inspect glass products, although the transparency of the glass material presents particular challenges for image capture and subsequent image processing.

[0015] To check the finger rest of a glass syringe barrel for both dimensional and cosmetic aspects, it is known to position the syringe barrel on a support surface of a handling unit and, if necessary, fix it there. Using an area-scan camera, the finger rest is directly optically recorded. This means that the area-scan camera is aimed directly at the finger rest and records it as a two-dimensional image. An area-scan camera is understood to be a camera with a two-dimensional sensor, which records the object to be recorded flatly in an XY plane, which results from an X direction and a Y direction perpendicular to this.

[0016] The syringe body is usually illuminated from the opposite rear side of the glass syringe, i.e. from the side of the syringe body bore and thus from the side of the finger rest, behind which the fingers grip during use. The finger rest is therefore illuminated from the side facing away from the area scan camera, past the side of the syringe body or through the syringe body. The light source for the illumination is usually flat and its area generally corresponds roughly to the area of ​​the object to be illuminated in order to save space for the image processing system. For the same reasons, both the area scan camera and the light sources are arranged as close as possible to the side of the syringe body to be imaged.

[0017] The disadvantage here is that the light source, due to its diameter roughly corresponding to the surface of the object to be illuminated, emits almost perfectly parallel light rays toward the syringe body. As a result, a large portion of the light rays are deflected by the bore, the syringe body, and the finger rest due to refraction on the glass surfaces, so that only very little light can be captured by the lens of the area scan camera. Therefore, the area scan camera tends to capture large black edges or areas, resulting in high contrasts from which no refracted light reaches the lens, making the determination of dimensional and cosmetic features only possible with insufficient quality for the described application.Furthermore, the support surface of the syringe body and its holder, which can both be components of a handling unit for guiding and positioning the syringe body during the inspection of the finger rest, are located between the light source and the area scan camera, which on the one hand causes shadows to be formed by these bodies, which also impairs the quality of the image capture, and on the other hand the support surface including the holder itself is partially captured by the image of the area scan camera.

[0018] To improve the image capture quality for the previously described system, a significant increase in the light source size and a significantly greater distance between the light source and the glass syringe would be required, allowing significantly more light rays to strike the syringe body overall and from other angles, reaching the lens of the area scan camera despite the previously described refractions. This would reduce the black edges and thus sharpen the captured image.

[0019] However, this is not feasible in practice because, in addition to increasing the cost of the image acquisition system itself, it would also increase the installation space of the image acquisition system. This would lead to an increase in the size of the production facility as a whole, which is highly undesirable due to the associated costs.

[0020] Furthermore, the support surface and the holder of the handling unit would still be visible in the captured image and would also continue to cast a shadow. This, in turn, would impair the quality of the image capture and thus at least partially cancel out the improvement achieved by magnifying the light source. Furthermore, the larger the light source or its illumination from the side opposite the area camera, the larger the shadow cast by the support surface and holder is; this argues against enlarging the light source in such an image capture system.

[0021] Alternatively, it is known to illuminate the glass syringe from the same side as the image is captured with the area scan camera. For this purpose, the illumination light sources can be arranged next to the area scan camera or around the area scan camera so that they shine directly onto the finger rest from the side from which the finger rest is being captured by the area scan camera. In order to exclude objects such as the support surface of the syringe body including the holder of the handling unit in the background from the image by the area scan camera, a veneer can be placed around the syringe body in this system. This veneer consists of two half-shells with cutouts for the syringe body, which are moved towards the syringe body in the area between the finger rest and the support and are flush with each other.

[0022] The disadvantage here is that this veneering is an additional measure and must be manufactured for the specific product. Furthermore, a gap at the point where the two half-shells close to form the veneer cannot be completely avoided. A gap also always remains between the veneer and the syringe body. These gaps can be detected by the area scan camera through the finger rest and interfere with the captured image. Furthermore, reflections can occur on the veneering, which can also reach the area scan camera through the finger rest and impair image capture.

[0023] EP 0 764 846 A1 describes a system for inspecting containers, particularly glass bottles. A container is held in a stationary position on its base and rotated about its vertical axis. Light energy is directed from below onto the base of the container as the container is rotated, and a camera receives a linear or one-dimensional image of the base of the container illuminated by the light energy from above through the neck of the container. The container image, which consists of a plurality of pixel data bytes, each of which forms a part of the image, is fed serially and sequentially to a programmable logic device in which an array of hardware logic elements is configured so that the elements of the array operate on a plurality of consecutive pixel data bytes simultaneously and in real time.The pixel data is analyzed to obtain inspection information as a function of the optical properties of the container.

[0024] EP 2 381 246 A1 describes a device for inspecting the surface of a translucent object, such as a glass syringe with an edge having an end face. The device has a carrier for carrying the object along its vertical axis, which carrier can be rotated about the vertical axis. A light source is provided inside the carrier and can emit light in a direction perpendicular to the vertical axis. The light source is enclosed as completely as possible by the carrier so that the light can be directed into an edge of the object and through it along its vertical axis. Thanks to the light directed into the object, cosmetic defects can be better detected with the human eye. This can also be done with an area scan camera, which is directed at the object perpendicular to the vertical axis.In this case, a small angular range of the cylindrical surface of the rotating object can be detected at a time, so that the curvature of the object does not cause interference.

[0025] EP 0 683 388 A1 describes a syringe being illuminated with light, for example, from the side. Image processing is performed on an image signal acquired by imaging light reflected from the edge of a syringe flange using a TV camera or a CCD camera obliquely from above. By detecting an irregular state of the image signal caused by the reflected light, a crack or chip in the flange is detected. The irregular state of the image signal obtained by detecting parts from which light is not reflected provides a method by which it is easy to detect a crack or chip in the flange.

[0026] The object of the present invention is to provide a system for optically detecting the finger rest of a glass syringe of the type described above, so that the image capture, in particular of dimensional and / or cosmetic features, can be improved with a compact design of the system.

[0027] The object is achieved according to the invention by the features of claim 1 and claim 10. Advantageous further developments are described in the subclaims.

[0028] Thus, as defined in claim 1, the present invention relates to a system for optically detecting a finger rest of a glass syringe, comprising a glass syringe having a cylindrical syringe body along its longitudinal axis with a front end having a bore and a rear end having a finger rest, and comprising an optical image capture unit for capturing the examination region of the vitreous body. The optical image capture unit has a line scan camera with a line-shaped detection region. The system further comprises a movement unit configured to move the glass syringe and the line scan camera relative to one another such that the finger rest of a glass syringe is guided over the detection region of the line scan camera, or vice versa.

[0029] A line scan camera is a type of camera that has only one light-sensitive line, i.e. a line sensor. In contrast, area scan cameras have a two-dimensional sensor that has a large number of lines (area sensors). In order to create a two-dimensional image with a line scan camera, the glass syringe to be scanned and the recording line scan camera must be moved relative to one another in order to be able to combine the individual line images captured one after the other to form the two-dimensional image. For this purpose, the line scan camera can be moved with its detection area over the finger rest of the stationary glass syringe, or the line scan camera can be stationary and the glass syringe moved relative to it.

[0030] The present invention is based on the finding that, due to the narrow detection range of the line scan camera, the image capture of interfering objects such as a support surface, its holder or other bodies of a handling or guiding unit of the glass syringe, which would also be captured with an area scan camera, can be completely avoided. In other words, the effects of the bodies of the handling unit, which are always required to hold and position the glass syringe during inspection of the finger rest, can be avoided by image capture using a line scan camera because the handling unit can be completely excluded from image capture due to the line-like detection of the finger rest. This can improve the quality of the image capture because it can be ensured that only the relevant examination area of ​​the glass syringe is captured.

[0031] According to a further aspect of the present invention, the movement unit is configured to rotate the glass syringe relative to the line-scan camera, or vice versa, about a longitudinal axis such that the finger rest of the glass syringe is guided over the detection area of ​​the line-scan camera, or vice versa. This can enable a compact relative movement of the glass syringe and the line-scan camera.

[0032] According to a further aspect of the present invention, the finger rest of the glass syringe or the detection area of ​​the line scan camera is aligned perpendicular to the longitudinal axis. The longitudinal axis forms the axis of rotation of the relative movement between the glass syringe and the line scan camera. This allows an image of the plane of the glass syringe to be captured perpendicular to the longitudinal axis or the axis of rotation. With a cylindrical glass body such as the glass syringe, the front area of ​​the bore or the rear area of ​​the finger rest can be captured across a surface in this way. Image capture using the line scan camera and the rotational relative movement of the glass syringe does not result in the usual optical image of an area scan camera, but rather a distorted representation of the surface of the glass syringe in this plane. However, the use of the line sensor enables this representation to be achieved with a much higher resolution and quality than with previous area scan cameras.Furthermore, this distorted representation can also be used, for example, for a target-actual comparison of correspondingly prepared target contours of the glass syringe in order to detect dimensional errors. Cosmetic defects can also be identified in this representation. Furthermore, areas of the handling unit may not be present in this image because they were not captured at all by using a line scan camera.

[0033] According to the claimed invention, the system is configured to move the glass syringe relative to the line scan camera.

[0034] In other words, the line scan camera is fixed and stands still. The glass syringe can be moved past the line scan camera in such a way that its finger rest is moved over the detection area of ​​the line scan camera. This is advantageous because the area scan camera is generally the larger and heavier object compared to the glass syringe and therefore moving it relative to the glass syringe would be more complex. Furthermore, the alignment of the finger rest and the detection area to one another can be made easier in this way when the lighter and smaller glass syringe is moved. This can also improve the quality of the image capture. The system according to the invention can also be more easily integrated into a mass-production glass plant in which the glass syringes are already moved in a synchronized manner through the various production stations.

[0035] According to a further aspect of the present invention, the system further comprises a lighting unit for illuminating at least the finger rest of the glass syringe. This lighting unit can improve the quality of image capture by increasing the brightness of the finger rest of the glass syringe. This allows more light rays to reach the line scan camera and be captured by its line sensor. This can sharpen the edges of the glass syringe. This can apply to both dimensional and cosmetic aspects.

[0036] The lighting unit can be a single light source or comprise a plurality of individual light sources that interact as a single lighting unit. Preferably, a plurality of LEDs (light-emitting diodes) are used as light sources. These LEDs are structured as evenly as possible and spaced apart from one another to produce the most diffuse and homogeneous lighting possible.

[0037] According to a further aspect of the present invention, the illumination unit is positioned closer to the finger rest of the glass syringe than the image capture unit. This allows the light to be brought as close as possible to the glass syringe or its finger rest to be captured. This can increase the light yield, i.e., the quantity of light rays available for image capture, and thus also the quality of the image capture.

[0038] According to a further aspect of the present invention, the illumination unit is positioned at a distance of less than 10 mm from the finger rest of the glass syringe. Up to this limit, the light output during image acquisition of glass syringes can be sufficiently high to detect dimensional and cosmetic features of the glass syringe with sufficiently high quality.

[0039] According to a further aspect of the present invention, the lighting unit is designed to generate a substantially rectangular illumination of the finger rest of the glass syringe, which corresponds at least to the detection range of the line scan camera. The expediency of the rectangular illumination of the finger rest results from the line-shaped detection range of the line scan camera, which, due to its line shape, can also be regarded as rectangular. In order to be able to illuminate this line completely and evenly, a lighting unit which essentially corresponds to this shape may be sufficient, i.e. has a low height but a large width, so that it can completely illuminate the line sensor but does not extend significantly beyond its extent.Such an illumination unit can thus be formed from a flat, wide, and continuous light source, eliminating darker intermediate areas between the individual light sources that could lead to inhomogeneous illumination. If the illumination unit is formed from individual point light sources, such as LEDs, these can still be positioned more densely across the wide area of ​​the line scan camera, thus improving the homogeneity of their illumination compared to a planar illumination arrangement, because the individual LEDs can be more easily accessible from the two remaining sides than with a planar arrangement of LEDs.

[0040] According to the invention, the glass body has at least one additional region located between the finger rest of the glass syringe and the image capture unit. This additional region can be arranged away from the illumination unit, allowing the illumination arrangement to be positioned closer to the finger rest of the glass syringe. This can improve the illumination of the finger rest and thus the quality of image capture.

[0041] According to the invention, the image capture unit is designed to capture the finger rest of the glass syringe on the outside of the syringe body along the longitudinal axis. In other words, the line scan camera can capture the finger rest of the glass syringe past at least part of the glass body. In the case of a glass syringe, this can be the syringe body and the bore, for example. In this case, it can be accepted that parts of the finger rest are at least partially covered by other areas, such as the syringe body. However, this arrangement can make it possible to position the lighting unit as close as possible to the finger rest, thereby maximising the light output. This can increase the quality of the image capture, even if the finger rest has to be captured by the line scan camera from further away and partly past the glass syringe. The finger rest can be captured by the image capture unit both directly, i.e. via the image sensor and the field of view.The optical path can be deflected either directly, i.e., without deflecting the beam path, or indirectly, i.e., with deflection of the beam path, e.g., via mirrors. The latter arrangement has the advantage of creating greater flexibility in the arrangement of the components of the image acquisition system according to the invention. Furthermore, it may potentially result in a more compact design of the image acquisition system.

[0042] According to the invention, the image capture unit has a lens with such a large focal length that light rays from the finger rest of the glass syringe can be captured approximately parallel by the lens. This is understood to mean an almost telecentric focal length, where the light rays run almost perfectly parallel to one another, i.e., the focal point lies approximately at infinity. Such a large focal length can enable the line scan camera to capture the finger rest of the glass syringe past the syringe body, i.e., over it, which could otherwise at least partially obscure the finger rest, particularly due to its edges.

[0043] According to the invention, the lens has a telecentric focal length or a hypercentric focal length. With a telecentric focal length, the focal point is at infinity, and the light rays are ideally parallel to each other. With a hypercentric focal length, distant but equally sized objects in the image plane are displayed larger than closer ones. In both cases, it can be ensured that the syringe body of the glass syringe can only obscure the areas of the finger rest directly behind it, while the image capture unit can safely view past it in parallel.

[0044] According to a further aspect of the present invention, the movement unit comprises a drive unit configured to move the glass syringe relative to the line scan camera, or vice versa. This allows the necessary relative movement between the finger rest and the detection area to be implemented directly by the image acquisition system itself. Preferably, the glass syringe is moved relative to the line scan camera by the movement unit. This minimizes the effort required for the relative movement, since the glass syringe is generally smaller and lighter than the line scan camera.

[0045] According to a further aspect of the present invention, the system further comprises a guide unit configured to guide the glass syringe during a relative movement to the line scan camera, or vice versa. The relative movement can preferably be rotational, since the glass syringe is a cylindrical body, such as, in particular, a syringe body. This can assist the handling or movement of the glass syringe or the line scan camera, because it can be held by the guide unit during the relative movement. This can be particularly important because, during the relative movement, the finger rest and the detection area must be aligned with one another in a reproducible and predetermined manner.

[0046] The present invention also relates, as defined in claim 10, to a method for optically detecting a finger rest on a glass syringe. The details and advantages of the method according to the invention are evident from the system according to the invention described above.

[0047] An embodiment and further advantages of the invention are explained below in conjunction with the following figures. Therein: Fig. 1 is a schematic sectional view through a glass body in the form of a glass syringe along the longitudinal axis; Fig. 2a is a schematic plan view of a cylindrical examination area of ​​a glass syringe perpendicular to the longitudinal axis; Fig. 2b is a schematic plan view of a cylindrically interrupted examination area of ​​a glass syringe perpendicular to the longitudinal axis; Fig. 3 is a schematic sectional view through an image acquisition system for glass bodies in the form of glass syringes along the longitudinal axis according to the prior art; Fig. 4a is a schematic representation of a planar detection area of ​​a cylindrical examination area perpendicular to the longitudinal axis according to the prior art; Fig. 4b is a schematic representation of a planar detection area of ​​a cylindrically interrupted examination area perpendicular to the longitudinal axis according to the prior art;5a is a schematic sectional view through an inventive image acquisition system for vitreous bodies in the form of glass syringes along the longitudinal axis from the side; Fig. 5b is a schematic sectional view through an inventive image acquisition system for vitreous bodies in the form of glass syringes along the longitudinal axis from above; Fig. 6a is a schematic representation of a line-shaped acquisition region of a cylindrical examination region perpendicular to the longitudinal axis according to the present invention; and Fig. 6b is a schematic representation of a line-shaped acquisition region of a cylindrically interrupted examination region perpendicular to the longitudinal axis according to the present invention.

[0048] Fig. 1 shows a schematic sectional view through a glass body 1 in the form of a glass syringe 1 along the longitudinal axis L. The glass syringe 1 has a syringe body 10 which is cylindrical and rotationally symmetrical to the longitudinal axis L. The syringe body 10 has a first, front end 10a, at which a bore 11 is formed integrally with the syringe body 10, which bore receives a hollow needle 12 or cannula 12. The syringe body 10 further has a second, rear end 10b, at which a finger rest 13 is formed integrally in the form of a section protruding in the radial direction R, which section can be cylindrically closed or interrupted. A piston 14 projects at least partially from the second, rear end 10b of the syringe body 10 into its hollow interior, in which, for example, the medication to be administered via the hollow needle 12 can be contained.The glass syringe 1 has a total length C from the outer side of the finger rest 13 in the longitudinal direction L to the front, outer end of the bore 11.

[0049] Such a glass syringe 1, and in particular its finger rest 13, is to be inspected for quality within the framework of automated production by means of image capture and subsequent image processing. For this purpose, the image capture is to be performed after the completion of the glass syringe 1 itself, i.e., without the inserted plunger 14, the glued-in hollow needle 12, and the filled medication. In particular, the finger rest 13 is to be examined for dimensional and cosmetic features. Thus, the finger rest 13 of the glass syringe 1 represents the examination area 13 of the vitreous body 1 to be recorded.

[0050] Fig. 2a shows a schematic top view of a cylindrical examination area 13 of a glass syringe 1 perpendicular to the longitudinal axis L, i.e., the longitudinal axis L passes through the center of the view (not shown). The radial direction R extends perpendicularly from the longitudinal axis L. In the center of the illustration, the cylindrical bore 11 is shown as the inner circle, the syringe body 10 as the next larger central circle, and the finger rest 13 as the next larger circle. Fig. 2b shows a corresponding representation with a cylindrically interrupted examination area 13 of a glass syringe 1 in the form of a sectionally formed finger rest 13. This form of the finger rest 13 can also be considered as a truncated full circle.

[0051] Such finger rests 13 are conventionally optically examined as follows: Fig. 3 shows a schematic sectional view through an image acquisition system for glass bodies 1 in the form of glass syringes 1 along the longitudinal axis L according to the prior art. The glass syringe 1 is held with its syringe body 10 approximately centrally in the direction of the longitudinal axis L by a handling unit 40 by means of its support surface 41 from below and positioned in the image acquisition system. The support surface 41 is held and moved via a holder 42. If, in a mass production of glass syringes 1, the objects to be examined continuously pass through or past the image acquisition system, the glass syringe 1 to be examined can, for example, be lifted into the image acquisition system from below by means of the handling unit 40 and, after the image has been acquired, be placed back into the production process.

[0052] On the left side of the Fig. 3 an optical image capture unit 30 is arranged, which has a camera unit 31 in the form of an area scan camera 31. The area scan camera 31 has a lens 32 with which it is directly aligned with the finger rest 13 as the examination area 13. Ideally, the glass syringe 1 is positioned in the image capture system by the handling unit 40 with its longitudinal axis L such that its longitudinal axis L coincides with the corresponding longitudinal axis L of the lens 32. The lens 32 is radially at least slightly larger than the maximum radius R of the finger rest 13 in order to be able to reliably capture it completely as the examination area 13. The lens 32 is at a distance A from the finger rest 13.

[0053] On the right side of the Fig. 3 An illumination unit 20 is arranged, which is at a distance B from the bore 11. The illumination unit 20 is also cylindrical in shape, corresponding to the cylindrical glass syringe 1 and the cylindrical lens 32. The longitudinal axis L of the illumination unit 20 coincides with the longitudinal axis L of the lens 32. The illumination unit 20 is radially at least slightly larger than the maximum radius R of the object to be illuminated, ie, the finger rest 13, in order to illuminate its examination area 13 (cf. Fig. 4a, 4b) to be able to reliably illuminate the entire area. Since, even with very small glass syringes 1 or correspondingly small lenses 32, the illumination unit 20 projecting radially beyond them generally cannot be formed by a single light source, the illumination unit 20 has several individual light sources which together form the illumination unit 20.

[0054] The glass syringe 1, positioned by the handling unit 40 between the lens 32 and the illumination unit 20, is illuminated from the right by the light from the illumination unit 20, and a portion of the light rays from the glass syringe 1 are guided through the lens 32 to the area-scan camera 31, which captures it as a two-dimensional image. The lens 32 is configured to generate a detection area 33 for the area-scan camera 31 that completely captures the examination area 13 of the vitreous body 1, i.e., its finger rest 13, but excludes irrelevant areas around this area (cf. Fig. 4a, 4b) . Due to the size of the lighting unit 20, the complete illumination of the detection area 33 of the area camera 31 is ensured.

[0055] Fig. 4a shows a schematic representation of a flat detection area 13 of a cylindrical examination area 33 perpendicular to the longitudinal axis L according to the prior art, ie according to the system of Fig. 3 . Fig. 4b shows a corresponding schematic representation of a flat detection area 13 of a cylindrically interrupted examination area 33. In addition to the objects 10, 11, 13 of the glass syringe 1, as with regard to the Fig. 2a, 2b As described above, the rectangular detection area 33 (dashed line) of the area scan camera 31 is shown here, which extends in the X-direction and Y-direction. The detection area 33 completely covers the finger rest 13 as the examination area 13. The lighting unit 20 or the area illuminated by it extends at least slightly beyond the detection area 33 in both directions. The handling unit 40 or its support surface 41 and holder 42 are at least partially concealed by the finger rest 13 (dashed line) because, from the direction of the lens 32, they are located behind the finger rest 13 and in the detection area 33.

[0056] From the representations of the Fig. 4a, 4b The disadvantages of the prior art image capture system can be seen. Firstly, the handling unit 40 is always captured by the area scan camera 31, which hinders image processing in this sub-area of ​​the examination area 13 when detecting dimensional and cosmetic features. Furthermore, the lighting unit 20 is located furthest away from the finger rest 13 with respect to the glass syringe 1, which is, however, to be captured and thus illuminated by the lighting unit 20. Thus, only a portion of the light emitted by the lighting unit 20 reaches the lens 32 of the area scan camera 31. Furthermore, the handling unit 40 is located between the lighting unit 20 and the area scan camera 31, whereby the handling unit 40 creates a shadow in the capture area 33.

[0057] Fig. 5a shows a schematic sectional view through an image acquisition system according to the invention for vitreous bodies 1 in the form of glass syringes 1 along the longitudinal axis L from the side. Fig. 5b shows a corresponding representation from above. Fig. 6a shows a schematic representation of a line-shaped detection area 33 of a cylindrical examination area 13 perpendicular to the longitudinal axis L according to the present invention. Fig. 6b shows a corresponding schematic representation of a cylindrically interrupted examination area 13.

[0058] The image acquisition system according to the invention differs from known image acquisition systems essentially by the use of a line-scan camera 31 instead of an area-scan camera 31. The detection area 33 of a line-scan camera 31 is line-shaped (cf. Fig. 6a, 6b) and thus has a higher resolution than a line of an area camera 31. This alone improves the quality of the image capture. The image elements of this single line can have a width of only 11 µm. In the lateral view of the Fig. 5a The line of the line scan camera 31 is located as detection area 33 on the longitudinal axis L and is not shown due to its low height (cf. Fig. 6a, 6b) . In the top view of the Fig. 5b the line of the line camera 31 extends as detection area 33 over the width of the lens 32 (cf. Fig. 6a, 6b) .

[0059] The lighting unit 20 is correspondingly flat in height (cf. Fig. 5a ) but broad in its width (cf. Fig. 5b ) so that a lighting unit 20 with (as) continuous and homogeneous light emission as possible can be provided with a single elongated light source or a plurality of small and laterally closely spaced light sources (e.g. LEDs). This projects beyond the single-line detection area 33 both in height and width at least slightly so that the detection area 33 is completely and as homogeneously illuminated as possible, but no superfluous amounts of light are emitted into the adjacent areas outside the detection area 33. Also, inhomogeneously arranged light sources outside the detection area 33 would still affect the detection area 33 with their light and impair the homogeneous light source or homogeneous light sources. In other words, light differences due to the planar arrangement of several light sources in the second direction, iethe height of the area camera 31, through the single-line detection area 33 of the line camera 31. This improves the quality of the illumination of the detection area 33 and thus also the quality of the image capture.

[0060] A further improvement in image acquisition is achieved by reversing the arrangement of the image acquisition unit 33 and the illumination unit 20 compared to known image acquisition systems. In other words, the illumination unit 20 is arranged directly and as close as possible, preferably at a distance B of a maximum of 10 mm, directly to the finger rest 13 as the examination area 13. The image acquisition unit 30 is arranged on the opposite side of the glass syringe 1, namely aligned toward its bore 11, so that the line scan camera 31 captures the finger rest 13 across the entire glass syringe 1 and past the bore 11 and the syringe body 10.To ensure that the corners of the syringe body 10 at the first, front end do not obscure the finger rest 13, the lens 32 has a correspondingly large focal length that is almost telecentric, so that the light rays from the finger rest 13 strike the lens 32 parallel to the syringe body 10. This enables the extremely close positioning of the illumination unit 20 to the examination area 13, so that the improved illumination also improves the quality of the image capture of the finger rest 13. A simultaneous deterioration in the image capture of the finger rest 13 by the line scan camera 31 can be avoided by the (almost) telecentric design of the lens 32, so that the quality of the image capture can be further improved by reversing the usual arrangement of the illumination unit 20 and image capture unit 30.

[0061] A further significant improvement in image acquisition occurs because the handling unit 40 and a movement unit 50 are not captured by the line scan camera 31 and thus are neither visible in the captured image nor hinder the illumination of the examination area 13.

[0062] The movement unit 50 can also be referred to as a drive unit 50. It has a movement mechanism 51 in the form of a drive surface 51, which is held from above by a holder 52. The holder 52 can also move the drive surface 51 vertically in order to move the drive surface 51 towards a glass syringe 1 to be captured and, after the image has been captured, to remove the engagement surface 51 from the glass syringe 1 again. The drive surface 51 is located in the embodiment of the Fig. 5a from above onto the syringe body 10 and can thereby rotate the glass syringe 1 about its longitudinal axis L in order to guide the examination area 13, ie the finger rest 13, completely over the detection area 33 of the line camera 31 during the rotation and thereby create a two-dimensional image.

[0063] At the same time, the glass syringe 1 rests with its syringe body 10 at the bottom on the support surface 41 of the handling unit 40, which in this case is designed as a rolling surface 41 to interact with the drive surface 51. Alternatively, the movement unit 50 can be arranged below and the handling unit 40 above the glass syringe 10. BEZUGSZEICHENLISTE (Teil der Beschreibung)

[0064] ADistance between lens 32 and glass body 1 BDistance between illumination source 20 and glass body 1 CLength of glass body 1 from hole 11 to finger rest 13 LLongitudinal axis Rradial direction XX-direction of an acquired image YY-direction of an acquired image 1Vitreous body, glass syringe 10Syringe body 10aFirst, front end of the syringe body 10 10bSecond, rear end of the syringe body 10 11Bore 12Hollow needle, cannula 13Area of ​​the vitreous body to be examined 1, finger rest of the glass syringe 1 14Plunger 20Lighting unit, light source 30Optical image capture unit 31Camera unit, area or line scan camera, sensor unit 32Lens 33Detection area, pixels, image pixels 40Handling unit, guide unit 41Support surface, rolling surface 42Bracket 50Movement unit, drive unit 51Movement mechanism, drive surface 52Bracket

Claims

1. System for optically detecting a finger rest (13) of a glass syringe (1), comprising a glass syringe (1) which has, along its longitudinal axis (L), a cylindrical syringe body (10) having a front end (10a) with a bore (11) and having a rear end (10b) with a finger rest (13), comprising an optical image detection unit (30) for detecting the finger rest (13) of the glass syringe (1), wherein the optical image detection unit (30) comprises a line camera (31) having a line-shaped detection region (33), and comprising a movement unit (50) which is configured to move the glass syringe (1) and the line camera (31) relative to each other in such a way that the finger rest (13) of the glass syringe (1) is guided over the detection region (33) of the line camera (31), or vice versa, wherein the optical image detection unit (30) is configured to receive the glass syringe (1) such that at least the syringe body (10) of the glass syringe (1) is arranged along the longitudinal axis (L) between the finger rest (13) of the glass syringe (1) and the image detection unit (30), wherein the image detection unit (30) is configured to detect the finger rest (13) of the glass syringe (1) past the outside of the syringe body (10) of the glass syringe (1) along the longitudinal axis (L), wherein the image detection unit (30) has a lens (32) that has such a large focal length that light rays from the finger rest (13) of the glass syringe (1) can be detected approximately in parallel by the lens (32), wherein the lens (32) has a telecentric focal length or a hypercentric focal length.

2. System according to claim 1, wherein the movement unit (50) is configured to rotate the glass syringe (1) relative to the line camera (31), or vice versa, about the longitudinal axis (L) such that the finger rest (13) of the glass syringe (1) is guided over the detection region (33) of the line camera (31), or vice versa.

3. System according to claim 2, wherein the finger rest (13) of the glass syringe (1) or the detection region (33) of the line camera (31) is aligned perpendicular to the longitudinal axis (L).

4. System according to any of the preceding claims, further comprising an illumination unit (20) for illuminating at least the finger rest (13) of the glass syringe (1).

5. System according to claim 4, wherein the illumination unit (20) has a smaller distance (B) from the finger rest (13) of the glass syringe (1) than the image detection unit (30).

6. System according to either claim 4 or claim 5, wherein the illumination unit (20) has a distance (B) of less than 10 mm from the finger rest (13) of the glass syringe (1).

7. System according to any of claims 4 to 6, wherein the illumination unit (20) is configured to generate a rectangular illumination of the finger rest (13) of the glass syringe (1), which illumination corresponds at least to the detection region (33) of the line camera (31).

8. System according to any of the preceding claims, wherein the movement unit (50) has a drive unit (51) which is configured to move the glass syringe (1) relative to the line camera (31), or vice versa.

9. System according to any of the preceding claims, further comprising a guide unit (40) which is configured to guide the glass syringe (1) during a relative movement with respect to the line camera (30), or vice versa.

10. Method for optically detecting a finger rest (13) of a glass syringe (1) by means of a system according to any of the preceding claims, wherein the glass syringe (1) and the line camera (31) are moved relative to each other such that the finger rest (13) of the glass syringe (1) is guided over the detection region (33) of the line camera (31), or vice versa, wherein the optical image detection unit (30) is configured to receive the glass syringe (1) such that at least the syringe body (10) of the glass syringe (1) is arranged along the longitudinal axis (L) between the finger rest (13) of the glass syringe (1) and the image detection unit (30), wherein the image detection unit (30) is configured to detect the finger rest (13) of the glass syringe (1) past the outside of the syringe body (10) of the glass syringe (1) along the longitudinal axis (L), wherein the image detection unit (30) has a lens (32) that has such a large focal length that light rays from the finger rest (13) of the glass syringe (1) can be detected approximately in parallel by the lens (32), wherein the lens (32) has a telecentric focal length or a hypercentric focal length.