KR102682167B1 - Apparatus and method for testing rod-shaped articles of the tobacco processing industry - Google Patents

Abstract

The present invention relates to an apparatus (32) and method for optically inspecting rod-shaped products (2) in the tobacco processing industry. The rod-shaped product 2 is each pre-packaged with a plurality of segments 6a...6e. The device 32 comprises a transport member 34 for transverse transport of the rod-shaped product 2, comprising a plurality of receiving recesses 36 in which the rod-shaped product 2 can be received. . The device 32 further comprises an image capture device 18 capable of capturing the rod-shaped product 2 disposed within the receiving recess 36 during transverse transport. The image capture device 18 includes a camera assembly 14 having a plurality of cameras 16a...16e for image capture arranged side by side in the longitudinal extension direction A of the receiving recess 36. Cameras 16a..16e include entocentric objectives 4a..4e. The image fields 20a, 20b of the cameras 16a..16e are the central imaging areas, respectively, which the objectives 4a..4e image without distortion and are surrounded by imaging edge regions 24a, 24b with greater distortion. Includes (22a, 22b). Cameras 16a...16e are arranged so that the central imaging areas 22a, 22b of adjacent cameras 16a...16e overlap each other. The processing unit 38 is configured to calculate the image data captured in the central imaging area 22a, 22b by the at least two cameras 16a... 16e into a common image of the camera assembly 14.

Description

Apparatus and method for testing rod-shaped products in the tobacco processing industry {APPARATUS AND METHOD FOR TESTING ROD-SHAPED ARTICLES OF THE TOBACCO PROCESSING INDUSTRY}

The present invention relates to a device in the tobacco processing industry for optically inspecting rod-shaped products of the tobacco processing industry, each rod-shaped product being prepackaged of a plurality of segments, the device comprising: comprising a conveying member for directional conveying, the conveying member comprising a plurality of receiving recesses in which a rod-shaped product can be or is received, wherein the device includes a rod-shaped product disposed within the receiving recesses during transverse conveying. It further includes an image capture device capable of or capturing an image. The present invention also relates to a method for optically inspecting a rod-shaped product in the tobacco processing industry, wherein the rod-shaped product is each pre-packaged of a plurality of segments, which are positioned transversely within a receiving recess of the conveying member by means of a conveying member. transported in the direction

Rod-shaped products from the tobacco processing industry that are pre-packaged of a plurality of segments are known, for example, as multi-segment filters. When assembling filter segments, errors may occur, for example, reversal of a filter segment, missing filter segments, wrong position, or insertion of a filter segment with the wrong length. Additionally, gaps between filter segments may occur or the filter segments may be tilted relative to each other.

To detect these errors during manufacturing, EP 1 769 689 A1 discloses an apparatus for measuring the properties of multi-segment filters or pre-packaging of filter segments in the tobacco processing industry. The multi-segment filter assembly is illuminated with a line laser. The light reflected from the surface of the filter segment is received by a line scan camera, and the data captured by this line scan camera is evaluated accordingly.

Another device for inspecting multi-segment filters while they are being transported transversely on a hauling drum is known, for example, from DE 10 2009 041 320 A1. The hauling drum is provided with a lighting device. The multi-segment filter is received within a slot-shaped receiving portion of this transport member, for example a receiving recess. A further provided sensor device absorbs radiation passing through the multi-segment filter or through an assembly of a plurality of segments present within the receiving recess. Observation is made through a mirror, and the emitted radiation is collimated through a lens and sent to a CCD camera. In this transmitted light method, especially filter segments filled with activated carbon can be detected well.

If the distances between segments of a rod-shaped product transported transversely on a hauling drum are to be measured with high precision, a line scan camera with very high resolution would be required in the conventional solutions mentioned above. However, these cameras have high operating costs and are also expensive to purchase. Additionally, the segment assembly must be imaged without or without distortion on a line scan camera, which requires telecentric optics. In the case of telecentric optics, the light bundle in the area of the object under consideration is incident parallel to the optical axis into the front lens of the objective lens. For this reason, the telecentric objective is required to include a front lens of the same size or larger than the maximum size of the object to be observed. This requirement makes telecentric optics in particular very expensive. Additionally, telecentric optics are quite large and heavy, so the design effort to implement the measurement assembly is correspondingly complex and expensive. Additionally, since a large structural space is required, this actually causes many problems during implementation.

The object of the present invention is an apparatus in the tobacco processing industry for optically inspecting rod-shaped products in the tobacco processing industry and a device in the tobacco processing industry for optically inspecting rod-shaped products in the tobacco processing industry, in which accurate inspection of rod-shaped products can be performed with high resolution, but the design effort remains low. To provide a method for optically inspecting rod-shaped products.

The above object is a device in the tobacco processing industry for optically inspecting rod-shaped products in the tobacco processing industry, wherein each rod-shaped product is pre-packaged of a plurality of segments, and the device is a transport device for transporting the rod-shaped product in the transverse direction. comprising a member, the conveying member comprising a plurality of receiving recesses in which a rod-shaped product can be received or is received, wherein the device is capable of capturing a rod-shaped product disposed within the receiving recess during transverse transfer, or An apparatus in the tobacco processing industry further comprising an image capture device for capturing images, wherein the image capture device comprises a camera assembly having a plurality of cameras for capturing images, the cameras being particularly configured to simultaneously capture images. synchronized, the cameras are arranged side by side in the direction of the longitudinal extension of the receiving recess, each camera of the camera assembly comprising an entocentric or at least approximately entocentric objective, thereby providing the receiving recess during transverse transfer. The object field passing through the rod-shaped product placed in the recess is imaged into an image field, the image field being imaged by the objective lens without distortion or at least with a distortion below a preset or presettable limit and with a greater distortion. It includes a central imaging area surrounded by imaging edge areas, wherein the camera is positioned within the camera assembly such that the central imaging areas of adjacent cameras overlap each other, and the image capture device further includes a processing unit, the processing unit being configured to: This is achieved by a device in the tobacco processing industry, characterized in that it is configured to calculate image data captured in a central imaging area by at least two, in particular all cameras, into a common image of the camera assembly.

Devices according to aspects of the invention utilize a camera assembly comprising a plurality of individual cameras arranged side by side, thereby eliminating conventional operational efforts, particularly the use of telecentric optics and the use of large line scan cameras with high resolution. It is based on technical considerations that it can be avoided. The individual images captured by these individual cameras are computed together after capture. In this context, it is advantageous if the cameras are synchronized, i.e. their individual images are captured simultaneously. These camera assemblies are collectively less expensive than corresponding large-format line scan cameras because the individual cameras can be standard products available at manageable prices. Additionally, it is advantageous that conventional entocentric optics can be used rather than special optics, for example telecentric optics. This means greater cost advantages. Characteristics of entocentric optical devices that are fundamentally unfavorable for measurement tasks, i.e. distortions, for example cushion-shaped or barrel-shaped distortions, do not play a significant role in the camera assembly according to an aspect of the invention. It does not negatively affect the measurements. This is achieved by excluding from the measurement the edge areas of the image area with high distortion. In other words, only the imaging area of the camera is used for the measurement task, located in the central area where the entocentric optics also image with almost no distortion.

Finally, it is very advantageous that the device according to one aspect of the invention does not require a large structural space. Entocentric optics are not overly large and can be purchased in good quality at a reasonably low price. Additionally, the object distance may be chosen to be relatively small, for example less than 100 mm, 200 mm, 300 mm or less than 500 mm.

The camera assembly is preferably arranged such that the rod-shaped product is imaged directly by the entocentric objective of the respective camera, without additional optical elements, for example one or more prisms, etc.

The camera of the camera assembly is a camera equipped with an area sensor (2D image sensor). Therefore, in particular line scan cameras are not used. The cameras of the camera device are specifically synchronized. In other words, image capture in particular is performed simultaneously by all cameras in the camera assembly.

In particular, the camera assembly includes a large number of individual cameras, making it possible to fully image the rod-shaped product as a whole in a central area of the cameras. After subsequent computation of the captured image data into a common image, there is a complete imaging of the rod-shaped product for subsequent analysis.

The device is particularly characterized in that the processing unit is further configured to quantitatively measure at least one intermediate space between two adjacent segments and/or at least one length of a segment of the rod-shaped product.

In addition to quantitative evaluation, qualitative evaluation may also be performed. For example, it is possible to evaluate the quality of the cutting edges of individual segments. This is advantageously possible because the optical inspection is performed in a top view, i.e. directly from above, by means of a camera assembly of the device according to one aspect of the invention. The viewing direction is at least approximately perpendicular to the direction of longitudinal extension of the rod-shaped product. In this regard, when optical inspection is performed with a single entocentric objective, the angle of view is flattened in the edge region, resulting in a view of the end faces of the individual segments, at least in the outer segments. This perspective makes qualitative assessment of the cutting edge difficult or inaccurate. Additionally, quantitative measurement of the intermediate space between adjacent segments or the length of segments of a rod-shaped product is difficult and inaccurate due to blurred edges. However, according to the device according to aspects of the invention, this is possible with the same or similar quality and accuracy as in the case of the use of a telecentric objective, at substantially lower cost and substantially smaller structural space.

With regard to quantitative assessment, the device may also, in particular, determine at least one distance between two adjacent segments in which the image capture device and the processing unit are oriented in the direction of longitudinal extension of the receiving recess and/or oriented in this direction of longitudinal extension. Characterized in that it is further configured to measure the length of the segment, in particular with an accuracy better than 0.1 mm.

For example, the resolution of the camera of the camera assembly is selected such that, at the selected object distance and optics used, the resolution of the camera is large enough to achieve the desired resolution. For example, the object distance is 200 mm and the maximum object length is also 200 mm. The resolution of the camera is, for example, 8,000 to 10,000 pixels. For example, more than four cameras are used in a camera assembly. Also, for example, the camera assembly includes 4, 6, 8 or 10 cameras. Advantageously, the device allows a very accurate measurement of the length of the segments of the rod-shaped product, as well as a very accurate measurement of the width of the individual interspaces between the segments.

The apparatus is also further configured, in particular, the processing unit to calibrate the cameras of the camera assembly, whereby image data of adjacent cameras captured in central image areas overlapping each other are evaluated and displacement vectors between the image areas of the adjacent cameras are determined. It is characterized by

The displacement vector determined in the area of calibration is applied to subsequent pictures, aligning them with respect to each other, so that an objective and accurately faithful representation of the rod-shaped product as a whole, i.e. in a common image, is available. Of course, this calibration is performed specifically on all cameras. Likewise, calibration can also be repeated during measurement tasks, for example at regular intervals.

It is also provided in particular that the camera of the camera assembly is sensitive in the visible spectrum region. For example, rod-shaped products are illuminated with overhead light or transmitted light. In particular, it is further provided that the illumination is continuous light or in particular flash light. That is, in other words, continuous illumination, for example, is not carried out. This requires synchronization of the flash light and the camera device. This synchronization is performed for example by a processing unit. The corresponding flash light operates simultaneously with the trigger of the individual cameras of the camera assembly. Image capture is therefore performed at the moment the rod-shaped product received in the receiving recess is illuminated by flash light. The flash device is thus synchronized with the camera of the camera assembly. Additionally, image capture is performed as the rod-shaped product received in the receiving recess is conveyed through the image field of the camera assembly. According to another embodiment, in particular, it is provided that the conveying member is a hauling drum through which the rod-shaped product is conveyed in the transverse direction.

The object is also achieved by an assembly in the tobacco processing industry comprising a device according to one or more of the embodiments described above, the assembly further comprising a rolling device, the device for optically inspecting rod-shaped products It is arranged upstream of the rolling device with respect to the transport direction of the rod-shaped product.

The rolling device includes, for example, a hauling drum on which the rod-shaped product is transported in the transverse direction and which feeds the rod-shaped product to roller blocks. The device for optically inspecting rod-shaped products is arranged, for example, so that the pre-packaging of a segment is captured directly on a hauling drum just before it is rolled into a lamella. In other words, the device for optical inspection is placed immediately before the rolling process.

According to a further aspect, it is provided that by means of said device for optically inspecting a rod-shaped product, a set of parameters is obtained which in particular completely describes the pre-packaging of the plurality of segments. This parameter set contains information about, for example:

- the presence of one or more segments,

- Number of segments present in pre-packaging,

- the location and/or type of the segment, where the type of segment is understood to mean, for example, its type and dimensions,

- the size of at least one gap between two adjacent segments,

- the size of the length of at least one segment

and/or

- the presence and/or location of a thin film layer provided to enclose the pre-packaging of the segments in the rolling device.

According to another embodiment, the assembly is configured to perform process control and/or regulation based on this set of parameters. For this purpose, the assembly is configured, for example, to perform an assignment between a rod-shaped product and a parameter set. If the rod-shaped product does not meet the predefined quality criteria due to deviations from preset set values of one or more parameters, the assembly is also configured to, for example, discharge this rod-shaped product after the rolling process and exclude it from further processing. In particular, it is also provided that parameter sets or individual values/parameters are used to subsequently control and/or regulate the process of pre-packaging the segments. For example, if the gap between segments is too small, this information can be used to subsequently adjust pre-packaging to ensure that the desired settings are maintained in subsequent pre-packaging.

Furthermore, it is particularly provided that the parameter set is used in the context of quality control for the detection of error sources. For example, defective base material can be identified.

In addition, the above object is a method for optically inspecting a rod-shaped product in the tobacco processing industry, wherein the rod-shaped product is each pre-packaged of a plurality of segments, and is transported in the transverse direction in the receiving recess of the conveying member by the conveying member. According to the method, wherein the rod-shaped product is captured by a plurality of cameras during transverse transport, the cameras are particularly synchronized, and the rod-shaped product is captured especially simultaneously, and these cameras are captured along the longitudinal axis of the receiving recess. Arranged side by side in the direction of directional extension, each camera images an object field partially containing the rod-shaped product entocentrically, or at least approximately entocentrically, into an image field, the image field being oriented without distortion by the camera's objective lens. or at least imaging with distortion below a preset or presettable threshold and comprising a central imaging area surrounded by imaging edge areas with greater distortion, the rod-shaped product such that the central imaging areas of adjacent cameras overlap each other. This is achieved by a method characterized in that image data captured in a central imaging area by at least two, in particular all cameras, are counted as a common image.

In this method for optically inspecting rod-shaped products, the same or similar advantages apply to those already mentioned above with regard to the device, so that repetition is avoided.

In particular, it is provided that image capture is performed with the aid of a camera comprising a two-dimensional image sensor. In particular, it is provided that the capture of the image of the rod-shaped product is carried out without any other optical elements, for example one or more prisms or mirrors, being present in the beam path. In other words, the camera captures the rod-shaped product directly through its entocentric objective.

According to an advantageous embodiment, it is provided that at least one intermediate space between two adjacent segments and/or at least one length of a segment of the rod-shaped product are measured quantitatively.

Furthermore, it is provided that the method is also adapted to qualitatively inspect a rod-shaped product or segment, for example with regard to the quality of the cutting edges.

In particular, it is provided that the width of one of the intermediate spaces oriented in the direction of longitudinal extension of the receiving recess and/or the length of the segment is measured in particular with an accuracy better than 0.1 mm. Advantageously, the method makes it possible to measure the width of the intermediate space between individual segments very precisely.

Also in particular, it is provided that the cameras are calibrated by the image data of adjacent cameras captured in the central image areas overlapping each other being evaluated and the displacement vectors between the imaging areas of the adjacent cameras being determined.

The method is also characterized in particular by capturing the rod-shaped product while it is being transported in the transverse direction on the hauling drum.

Furthermore, the above object is achieved by a method for controlling and/or regulating a rolling device in an assembly of the tobacco processing industry. The assembly includes a rolling device and a device for optically inspecting a rod-shaped product according to one or more of the embodiments described above. In the rolling device the pre-packaging of the segments is covered with a thin film layer. A rod-shaped product of the tobacco processing industry is inspected according to a method for optically inspecting a rod-shaped product of the tobacco processing industry according to one or more of the embodiments described above. This inspection is performed upstream of the rolling device relative to the direction of transport of the rod-shaped product.

The rolling device includes, for example, a hauling drum on which the rod-shaped product is transported in the transverse direction and which feeds the rod-shaped product to roller blocks. The inspection is performed directly on the hauling drum while the segments are being pre-packaged, for example just before they are rolled into the thin film layer.

According to another aspect, it is provided that when optically inspecting a rod-shaped product, a set of parameters is obtained that particularly completely describes the pre-packaging of a plurality of segments. This parameter set contains information about, for example:

- the presence of one or more segments,

- Number of segments present in pre-packaging,

- the location and/or type of the segment, where the type of segment is understood to mean, for example, its type and dimensions,

- the size of at least one gap between two adjacent segments,

- the size of the length of at least one segment

and/or

- the presence and/or location of a thin film layer provided to enclose the pre-packaging of the segments in the rolling device.

On the basis of this set of parameters, for example, process control and/or regulation is performed. For example, an assignment between a rod shape product and a parameter set can be performed. If a rod-shaped product does not meet predefined quality criteria due to deviations from preset set values of one or more parameters, this rod-shaped product can be discharged after the rolling process and excluded from further processing. In particular, it is also provided that parameter sets or individual values/parameters are used to subsequently control and/or regulate the process of pre-packaging the segments. For example, if the gap between segments is too small, this information can be used to subsequently adjust pre-packaging to ensure that the desired settings are maintained in subsequent pre-packaging. In particular, it is provided that the parameter set is used in the context of quality control for the detection of error sources. For example, defective base material may be identified.

Other features of the invention will become apparent from the description of embodiments according to the invention taken together with the claims and accompanying drawings. Embodiments according to the invention may fulfill individual features or a combination of multiple features.

The present invention will be described below without limiting the general inventive concept by way of examples with reference to the drawings, and all details according to the present invention that are not explained in detail in the detailed description are clearly indicated in the drawings. .

Figure 1 is a diagram schematically illustrating a structure according to the prior art, in which optical imaging of a rod-shaped product consisting of pre-packaging of a plurality of segments can be performed by an entocentric objective lens.
Figure 2 shows an image acquired by the assembly of Figure 1.
Figure 3 shows a camera assembly with a plurality of cameras for capturing images of a rod-shaped product consisting of pre-packaging of a plurality of segments in an apparatus in the tobacco processing industry.
Figure 4 shows the image fields of the first and second cameras of the camera assembly.
Figure 5 shows the image fields of the first and second cameras of the camera assembly corrected relative to each other.
Figure 6a shows an image acquired by a camera assembly, which is calculated by a processing unit from image data of individual images of a camera of the camera assembly.
Figure 6b shows in comparison the image already known from Figure 2.
Figure 7 shows a device in the tobacco processing industry for optically inspecting rod-shaped products of the tobacco processing industry, wherein the device includes a hauling drum for transporting the rod-shaped product in the transverse direction, the hauling drum having a rod-shaped It includes a plurality of receiving recesses in which products are received, and also includes an image capture device, whereby the rod-shaped product disposed in the receiving recesses is captured during lateral transport.

In the drawings, identical or similar elements and/or parts are each provided with the same reference numerals, thereby indicating each separately from the new idea.

Figure 1 schematically and schematically shows an optical arrangement according to the prior art for imaging a rod-shaped product 2 by an entocentric or nearly entocentric objective lens 4 . For reasons of simplicity, the entocentric objective 4 is represented by a single lens. The rod-shaped product 2 is pre-packaged of a plurality of segments 6a, 6b, 6c, 6d, and 6e. The entocentric objective 4 captures the object in object space at an opening angle α. The outer light beam in this angular range enters obliquely into the entrance lens of the objective lens 4. Due to this, the outer segments 6a, 6b and 6d and 6e, in particular the two outer segments 6a and 6e, are not directly observed from above, but are therefore perpendicular to the longitudinal direction L (shown as a dashed line). It can be observed from the viewing direction.

Figure 2 shows an exemplary simplified view of the resulting image of a rod-shaped product in the assembly known from Figure 1; Images of segments 6a..6e are marked 8a..8e. Besides the middle segment 6c (see reference numeral 8c), all segments 8a...8e are represented by at least a partial view of the end face 10 facing inwards, ie towards the center of the rod-shaped product 2. This situation does not allow the edges 12 of the segments 6a...6e of the rod-shaped product 2, shown in solid lines in the idealized schematic diagram of FIG. 2, to be captured selectively. Therefore, accurately measuring the distances D1 to D4 between segments 6a...6e is in terms of the accuracy achievable with the help of the entocentric optical system 4, as exemplarily shown in Figure 1. This is possible only in a significantly reduced state. Distances D2 and D3 can still be captured with reasonable accuracy, but it is no longer clear about distances D1 and D4. Additionally, it is not possible to capture the quality of edge 12 with sufficient accuracy.

An apparatus according to aspects of the present invention will present a solution herein, and various embodiments thereof will be described below. The device includes a transfer member described in detail later in relation to FIG. 7 . The device also comprises an image capture device, with which the rod-shaped product 2 can be or is captured while being transported in the transverse direction on the conveying member.

The image capture device includes a camera assembly 14 as shown schematically and schematically in FIG. 3 . Camera assembly 14 includes a plurality of cameras 16a, 16b, 16c, 16d, and 16e. Each camera 16a...16e is provided with an entocentric objective lens 4a...4e. The cameras 16a..16e of the camera assembly 14 together with their associated entocentric objectives 4a..4e form the image capture device 18. The image capture device 18 further comprises means for ensuring that the cameras 16a...16e of the camera assembly 14 are synchronized, for example suitable control or regulation devices. That is, cameras 16a...16e are triggered simultaneously, i.e. capture image data at the same time.

The image capture device 18 is configured to capture the rod-shaped product 2 disposed in a receiving recess of a transport member, for example a hauling drum, during its transverse transport. The individual cameras 16a...16e of the camera assembly 14 are arranged side by side in the direction of the longitudinal extension of the receiving recess of this transport member. This longitudinal extension direction A is shown by a dashed line in Figure 3 (see also Figure 7).

The objectives 4a...4e of the cameras 16a...16e of the camera assembly 14 are entocentric optics or approximately entocentric optics. For reasons of simplicity, the entocentric objectives 4a..4e are each represented as a single lens. Each objective 4a..4e captures the object field and images it on the sensor of the associated camera 16a..16e. The perspectives of cameras 16a...16e are shown as having respective opening angles α1, α2, α3, α4, α5. The opening angles (α1..α5) are at least approximately the same magnitude. Light incident into the objectives 4a..4e at opening angles α1..α5 is imaged on the central imaging area of the sensor of the cameras 16a..16e. The opening angles (α1..α5) of the entocentric objectives 4a..4e of the camera assembly 14 are all the same as the opening angles (α) of the entocentric objectives 4 shown in Figure 1 according to the prior art. ) is small compared to The opening angles (α1..α5) of the entocentric objectives 4a..4e overlap each other in object space. This overlapping area within object space should be indicated with reference numeral 26'. Light incident from the overlapping area 26' is received by two cameras 16a...16e, for example two adjacent cameras 16a and 16b, and imaged in the central imaging area 22a, 22b, respectively. . The rod-shaped product 2 passes through the object field during transverse transport and is captured by cameras 16a...16e.

Figure 4 exemplarily shows the image field 20a of the first camera 16a when imaged by the associated objective 4a onto an area sensor, for example a CMOS sensor, of this camera. Also shown is the image field 20b of the second camera 16b of the camera assembly 14. Each of the image fields 20a, 20b includes a central imaging area 22a, 22b. Light incident from object space into the objective lens 4a of the first camera 16a under angle α1 is imaged into the central imaging area 22a. This also applies similarly to the other cameras 16b..16e. Each central image area in object space should be indicated with reference numerals 22a' to 22e'. In these regions the associated objectives 4a, 4b image without or approximately without distortion. At least the distortion of the relevant objectives 4a, 4b is below a preset limit. For example, this may be expressed as a percentage of ideal imaging. This limit is for example less than 1%, especially less than 2%, more particularly less than 2.5%, more particularly less than 5%, and also an imaging error of less than 7.5%, more particularly less than 10% and even more especially less than 15%.

The central imaging areas 22a and 22b are surrounded by imaging edge areas 24a and 24b that have greater distortion than the central imaging areas 22a and 22b. In particular, the distortion in the imaging edge areas 24a, 24b is above one of the aforementioned limits. The cameras 16a...16e of the camera assembly 14 are arranged such that the central imaging areas 22a, 22b of adjacent cameras 16a...16e overlap each other. The overlap area 26 is the intersection between adjacent central imaging areas 22a, 22b of adjacent cameras 16a...16e.

The image capture device 18 is provided with a processing unit, which evaluates the image data of adjacent cameras 16a, 16e captured in the central image areas 22a, 22b overlapping each other, thereby processing the camera assembly 14. It is configured to calibrate the cameras 16a...16e. For example, a cross-correlation between image data of images of adjacent cameras in the overlap region 26 is calculated. By this comparison, a displacement vector 28 can be calculated by which the image fields 20a, 20b of adjacent cameras 16a, 16b are displaced relative to each other. In the embodiment shown in Figure 4, the displacement vector 28 is directed exclusively vertically. If the overlap area 26 is wider than desired or narrower than desired, the displacement vector 28 will additionally include a corresponding horizontal component. Displacement vectors 28 are calculated for all adjacent cameras 16a...16e of camera assembly 14.

The processing unit is now configured to calculate the image data captured by the cameras 16a... 16e of the camera assembly 14 in the central imaging area 22a, 22b into a common image of the camera assembly 14.

5 shows two image fields 20a, 20b of an exemplary camera 16a, 16 corrected by the displacement vector 28, where the image field 20b of the second camera 16b undergoes disambiguation. It is shown as a dotted line. The two central receptive fields 22a, 22b are merged, in which case image data from one or the other camera can optionally be used in the overlapping region 26.

By corresponding application of the mechanism described above, a complete image of the rod-shaped product 2 can be obtained from the individual image fields 20a to 20e, as shown schematically and simplified in FIG. 3 . Unlike the actual embodiment, in Figure 3 the image fields 20a..20e are shown, which are not represented overlappingly for reasons of clarity only.

As a result of this measurement, an image of the rod-shaped product 2 can be provided, as shown by way of example and schematically in FIG. 6A . Immediately below in FIG. 6b an image of the rod-shaped product 2 already known from FIG. 2 is shown, as obtainable by a single entocentric objective 4 . Preferably, the device according to an aspect of the invention provides imaging of a rod-shaped product 2, wherein the edges 12, of which only a few are given reference numbers for clarity, are clear and clearly recognizable. It can be. As a result, the distances D1..D4 between the individual segments 6a..6e can be determined very precisely, where these are the distances between the images 8a..8e of the corresponding segments 6a..6e. Calculated from (D1'..D4') under the knowledge of the imaging scale of the objectives (4a..4e).

In other words, the device ensures that the intermediate spaces 30 between adjacent segments 6a..6e of the rod-shaped product 2 (see Figure 3, only a few of which are given reference signs for clarity) are quantitatively It is configured so that it can be measured. The same applies to the lengths of segments 6a..6e.

The image capture device 18 is further configured to measure the distance D1..D4 between the segments 6a..6e in particular with an accuracy better than 0.1 mm. For this purpose, as shown in Figure 3, the resolution of the objectives 4a...4e and the resolution of the sensors used for the cameras 16a...16e (units), in particular depending on the acceptance distance B (object width) number of pixels or pixels per length) is selected so that the desired resolution is achieved.

Figure 7 shows an apparatus 32 of the tobacco processing industry for optically inspecting a rod-shaped product 2, wherein the rod-shaped product 2 is shown in Figure 7 as pre-packaging of a plurality of segments for reasons of simplicity. It didn't work. The device 32 comprises a hauling drum 34, shown in sections, as a conveying member. There is a receiving recess 36 on the surface of the holding drum 34 in which the rod-shaped product 2 is accommodated during transport in the transverse direction in the transport direction R. The transport direction (R) corresponds to the rotation direction of the hauling drum. At the top of the receiving recess 36 is the image capture device 18 already described above, of which only a few camera units are schematically shown, each comprising a camera and an entocentric objective. The receiving recess 36 has a longitudinal extension direction A, which has already been mentioned in connection with FIG. 3 and is also shown in dashed lines in FIG. 7 . The direction of longitudinal extension (A) is oriented at least approximately perpendicular to the transport direction (R). The individual cameras 16a...16e of the camera assembly 14 of the image capture device 18 are arranged side by side in this longitudinal direction of extension A. Therefore, it is possible to optically inspect the rod-shaped product 2 during transport in the transverse direction on the transport member 34.

The device 32 further comprises a processing unit 38 , such as a computer, work station, etc., which controls and reads, inter alia, the image capture device 18 , performs the mentioned calibration, and controls the camera assembly 14 ) is configured to calculate the common image of.

All the features mentioned that can be inferred alone from the drawings, as well as individual features disclosed in combination with other features, both alone and in combination, are considered essential to the invention. Embodiments according to the invention may be achieved by a single feature or a combination of multiple features. In the context of the present invention, features expressed by “in particular” or “preferably” should be understood as optional features.

2: Rod-shaped product 4, 4a..4e: Entocentric objective lens
6a..6e: Segment 8a..8e: Image
10: end face 12: cutting edge
14: Camera assembly 16a..16e: Camera
18: image capture device 20a, 20b: image field
22a, 22b, 22a'..22e': central imaging area
24a, 24b: imaging edge area 26, 26': overlap area
28: Displacement vector 30: Middle space
32: Device in the tobacco processing industry 34: Conveying member
36: receiving recess 38: processing unit
α, α1..α5: Opening angle L: Longitudinal direction
D1..D4, D1'..D4': Distance A: Longitudinal extension direction
R: transfer direction

Claims (11)

A device (32) in the tobacco processing industry for optically inspecting a rod-shaped product (2) of the tobacco processing industry, wherein the rod-shaped product (2) is each prepackaged in a plurality of segments (6a..6e). The device 32 includes a transfer member 34 for transporting the rod-shaped product 2 in the transverse direction, and the transport member 34 can accommodate the rod-shaped product 2. or comprising a plurality of receiving recesses 36 to be received, wherein the device 32 is capable of capturing or capturing the rod-shaped product 2 disposed within the receiving recesses 36 during the transverse transfer. A device (32) in the tobacco processing industry, further comprising an image capture device (18) that:
The image capture device 18 includes a camera assembly 14 having a plurality of cameras 16a..16e for image capture, the cameras 16a..16e being positioned along the receiving recess 36. Arranged side by side in the direction of extension A, each camera 16a...16e of the camera assembly 14 comprises an entocentric objective lens 4a...4e, thereby The object field passing through the rod-shaped product 2 disposed in the receiving recess 36 during transport is imaged into image fields 20a, 20b, which are imaged by the objective lens 4a. ..4e) imaging without distortion or at least with distortion below a preset or presettable limit and having a central imaging area 22a, 22b surrounded by imaging edge areas 24a, 24b with greater distortion. wherein the cameras 16a...16e are disposed within the camera assembly 14 such that the central imaging areas 22a, 22b of adjacent cameras 16a...16e overlap each other, and the image capture device 18 ) further comprises a processing unit 38, which processes image data captured in the central imaging area 22a, 22b by at least two cameras 16a... 16e of the camera assembly 14. Device in the tobacco processing industry, characterized in that it is configured to calculate with a common image of said camera assembly (14). 2. The processing unit (38) according to claim 1, wherein the processing unit (38) is located in at least one intermediate space (30) between two adjacent segments (6a..6e) or in one of the segments (6a..6e) of the rod-shaped product (2). A device in the tobacco processing industry, characterized in that it is further configured to quantitatively measure at least one length or both. 3. The method according to claim 2, wherein the image capture device (18) and the processing unit (38) are positioned between two adjacent segments (6a..6e) oriented in the longitudinal extension direction (A) of the receiving recess (36). Device in the tobacco processing industry, characterized in that it is further configured to measure at least one distance (D1..D4) or the length of the segments (6a..6e) oriented in the longitudinal extension direction (A) or both. . 4. The method according to any one of the preceding claims, wherein the processing unit (38) is configured to: further configured to calibrate said cameras (16a..16e) of said camera assembly (14) by evaluating and determining displacement vectors (28) between said image fields (20a, 20b) of adjacent cameras (16a..16e). A device for the tobacco processing industry, characterized in that. 4. Device according to any one of claims 1 to 3, characterized in that the conveying member (34) is a hauling drum. An assembly in the tobacco processing industry comprising a device according to any one of claims 1 to 3 and a rolling device, comprising:
The assembly of the tobacco processing industry, wherein the device for optically inspecting the rod-shaped product (2) is arranged upstream of the rolling device with respect to the direction of transport of the rod-shaped product (2). A method for optically inspecting a rod-shaped product (2) of the tobacco processing industry, wherein the rod-shaped product (2) is pre-packaged of a plurality of segments (6a...6e), each of which is separated by a transport member. In the above method, which is transported in the transverse direction in the receiving recess (36),
The rod-shaped product 2 is captured by a plurality of cameras 16a...16e during transport in the transverse direction, and the cameras 16a...16e are positioned in the longitudinal extension direction (A) of the receiving recess 36. ), each camera 16a, 16e entocentrically images an object field partially containing the rod-shaped product 2 into image fields 20a, 20b, the image fields 20a, 20b 20a, 20b) is configured such that the objective lens 4 of the camera 16a..16e images without distortion or at least with distortion below a preset or presettable limit and imaging edge areas 24a, with greater distortion. 24b), wherein the rod-shaped product 2 is imaged such that the central imaging areas 22a, 22b of adjacent cameras 16a, 16e overlap each other. and the image data captured in the central imaging area (22a, 22b) by at least two cameras (16a...16e) are calculated as a common image. 8. The method according to claim 7, characterized by at least one intermediate space (30) between two adjacent segments (6a..6e) or at least one length of segment (6a..6e) of said rod-shaped product (2) or both. A method characterized in that is measured quantitatively. 9. The width of the intermediate space (30) oriented in the direction of longitudinal extension (A) of the receiving recess (36) or the segments (6a...6e) oriented in the direction (A) of the longitudinal extension of the receiving recess (36). A method characterized in that the length of or both are measured. 10. The method according to any one of claims 7 to 9, wherein the camera (16a..16e) captures the image of an adjacent camera (16a..16e) in the overlapping central image area (22a, 22b). Characterized in that the data is evaluated and the displacement vector (28) between the imaging areas (22a, 22b) of adjacent cameras (16) is determined, thereby being calibrated. 10. Method according to any one of claims 7 to 9, characterized in that the rod-shaped product (2) is captured while being transported in the transverse direction on a hauling drum.

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