Method and apparatus for inspecting rod products in the cigarette industry

Abstract

The present invention relates to a method and device for inspecting rod-shaped products (11) of the cigarette industry, in particular tobacco sticks, each having one particularly cylindrical side (22) and two particularly visually identical end faces (23, 24) arranged at opposite ends, in particular constituted by two filter elements of different lengths, in which the rod-shaped products (11) comprise smokable material, in particular tobacco, in a portion arranged preferably off-center between the end faces (23, 24), a) irradiating a side surface (22) of at least one rod-shaped product (11) to be inspected with inspection light, in particular with inspection light whose rays strike the side surface (22) at an angle of at least 30°, preferably at least 60°, and particularly preferably 90°, relative to the longitudinal extent of the rod-shaped product (11), so that the inspection light enters the rod-shaped product (11) at least partially via the side surface (22) and exits again at least partially via one end surface (23, 24); b) detecting the inspection light exiting the end surface (23, 24) of the rod-shaped product (11) with an electro-optical receiver for the inspection light, in particular a camera, associated with the end surface (23, 24) and whose main viewing direction is directed towards the end surface (23, 24); and c) evaluating the inspection light exiting the end surface (23, 24) and detected by the electro-optical receiver, in particular in terms of brightness or light intensity.

Description

[Technical Field]

[0001] The present invention relates to a method for inspecting rod-shaped products, in particular tobacco sticks, for the cigarette industry, each having two end faces, in particular cylindrical, and in particular visually identical, constituted by two filter elements, particularly preferably of different lengths, arranged at opposite ends, in which the rod-shaped products are provided with smokable material, in particular tobacco, in a portion, preferably arranged off-center, between the end faces.Furthermore, the present invention relates to an apparatus for inspecting such products. [Background technology]

[0002] In the tobacco or cigarette industry, various inspection methods for cigarettes or other rod-shaped products are known, and these inspection methods are regularly used within the packaging process of such products. During such packaging processes, rod-shaped products are often grouped into separate product groups having one or more product layers in which the cigarettes are located side by side and oriented in the same predetermined manner. Within such product groups, conventional cigarettes are typically oriented so that the end faces formed by the filter ends together form a first product group face, and the end faces formed by the tobacco ends form an opposing second product group face. The product groups are then combined into respective packs, for example, conventional cigarette packs. In this context, it is particularly necessary to identify whether individual cigarettes within a product group are incorrectly positioned rotated by 180°, i.e., whether, for example, the filter ends of the cigarettes are incorrectly aligned within the product group face formed by the tobacco ends of the cigarettes. For this purpose, it is known, for example, to record images of the filter ends of the cigarettes in the product group using a camera and then identify the incorrectly present tobacco ends therein using image identification techniques.

[0003] However, this method is useless when the ends of the rod-shaped product are not or only poorly visually distinguishable from one another, as may be the case, for example, with new products in the cigarette industry, such as tobacco sticks ("heat-to-serve"), which are known to be formed at both ends by filters whose end faces are visually identical.

[0004] In such cases, it is conceivable to provide an off-center imprint on the side of each bar and use a camera to detect the side, and thus the imprint, thus identifying incorrect orientation of individual bars within a product group. This is because in such cases, each imprint would appear in an incorrect or unexpected position in the recorded image. However, this method is expensive, since it requires providing an imprint on every bar. In addition, for product groups with three or more product layers, it is no longer possible to use the product group without error, because the middle product layers would be covered by the outer product layers and therefore could not be inspected by the camera. Summary of the Invention [Problem to be solved by the invention]

[0005] Based on this, the object of the present invention is to develop the method and the device mentioned at the beginning, in particular so that rod-shaped products having ends or end faces that are not or only poorly distinguishable optically can also be reliably inspected. [Means for solving the problem]

[0006] This problem is solved by a method having the features of claim 1 and a device having the features of claim 13.

[0007] Accordingly, a) irradiating the side of at least one rod-shaped product to be inspected with inspection light, in particular with inspection light whose rays strike the side at an angle of at least 30°, preferably at least 60°, particularly preferably 90°, relative to the longitudinal extent of the rod-shaped product, so that the inspection light enters the rod-shaped product at least partially via the side and exits again at least partially via one end face; b) detecting the inspection light emerging from the end face of the rod-shaped product to be inspected by an electro-optical receiver for the inspection light, in particular a camera, associated with the end face and having a main viewing direction directed towards the end face; c) evaluating the test light emerging from the end face and detected by an electro-optical receiver, in particular in terms of brightness or light intensity; The present invention provides a method for inspecting rod products of the cigarette industry as mentioned in the introduction, comprising:

[0008] It has been found that the optical inspection method described above allows for confirmation of the orientation of rod-shaped products in many cases, even when the end surfaces are visually identical, for example, when both ends are provided with filter elements, as in the case of tobacco sticks for electric cigarette heaters. In particular, if a portion of the smokable material is arranged off-center in the rod-shaped product, i.e., not symmetrically arranged with respect to a central plane extending perpendicular to the rod-shaped product's longitudinal axis, due, for example, to differences in the lengths of the filter elements, this results in different absorption of light (with respect to the inspection light) depending on the direction along the rod-shaped product's longitudinal axis, i.e., from one end surface to the other. This directional dependence of absorption can thus be exploited in accordance with the present invention. However, even if the two filter elements are the same length and the smokable material is centrally located, such direction-dependent absorption is theoretically possible. For example, this portion, especially the off-center portion, may contain an additional absorbing element, such as an aroma capsule.

[0009] It goes without saying that the method according to the present invention can also be used in the case of a conventional cigarette having a tobacco end and a filter end.

[0010] Within the scope of this application, rod products of the cigarette industry may be rod products having essentially conventional smokable material, such as cigarettes, cigarillos, etc., but may alternatively also be rod products having smokable material, such as tobacco sticks for electronic tobacco products (with or without aroma capsules).

[0011] In a preferred embodiment of the present invention, when one or more products each having a portion of smokable material disposed off-center are being inspected, each side of each rod-shaped product can be illuminated with an inspection beam of inspection light such that, after the inspection beam strikes the side at a first orientation of each rod-shaped product on its path to the electro-optical receiver, it does not penetrate the smokable material within the rod-shaped product or penetrates a short portion of the smokable material, but the inspection beam remains unchanged or the beam path of the inspection beam striking the side remains unchanged, and the inspection beam then penetrates the smokable material within the rod-shaped product or a long portion of the smokable material within the rod-shaped product at a second orientation 180° opposite to the first orientation of each rod-shaped product, whereby different light intensities arise at the receiver based on differences in absorption of the inspection beam, respectively, depending on the orientation of the rod-shaped product, from which the actual orientation of each rod-shaped product can be determined.

[0012] Preferably, the brightness or light intensity of the detected inspection light can be compared with a reference value stored in memory or with the brightness or light intensity of inspection light exiting from the other end face of the opposite end of the same rod-shaped product or from one end face of another rod-shaped product, the side of the other rod-shaped product being irradiated with inspection light so that the inspection light enters the rod-shaped product at least partially through the side face and exits again at least partially through the end face, and the inspection light exiting from the end face of the other rod-shaped product is detected and evaluated by the electro-optical receiver or said electro-optical receiver.

[0013] Preferably, according to the invention, an entire product group or product formation of rod-shaped products can be inspected, which product group or product formation each comprises one or more product layers of rod-shaped products arranged side by side in a row, the end faces of the opposite ends of these rod-shaped products each constituting one of two opposite product group faces.

[0014] In this case, the side of each rod-shaped product of one or more product layers of the product group, preferably one or both outer product layers, can be illuminated with inspection light, and the inspection light emerging from the end face of at least one of the rod-shaped products of both opposing product group faces is received and evaluated by an electro-optical receiver associated with these end faces or the electro-optical receiver.

[0015] Each of the opposing end faces of a rod-shaped product or multiple rod-shaped products may be associated with a separate electro-optical receiver for detecting the inspection light emitted from each, and both the inspection light emitted from one and the other of the opposing end faces and detected by the associated electro-optical receivers are evaluated.

[0016] With respect to the associated (respective) electro-optical receiver, its main viewing direction may extend perpendicular to one or both end faces of the rod or rods.

[0017] The associated electro-optical receiver or each associated electro-optical receiver can preferably be formed as a camera, in particular as a CCD camera or a CMOS camera, the camera or each camera recording a particularly common real image of one or more end faces, and the real image or each real image is then evaluated.

[0018] In this case, within the scope of the evaluation of the real image, the brightness or light intensity of the end face of the rod-shaped product imaged in the real image can be compared with a stored reference value. Optionally, within the scope of the evaluation of the real image, the brightness or light intensity of the end face imaged in the real image can be compared with the brightness or light intensity of at least one other end face of a rod-shaped product of the same or another product layer imaged in the real image, respectively.

[0019] A separate electro-optical receiver, in particular configured as a camera, can be associated with each end face of the or each rod-shaped product for detecting the inspection light emitted therefrom, in particular with a main viewing direction of each camera oriented perpendicular to the end face associated with it, each camera recording a real image of the end face associated with it, and these real images being evaluated by comparing the brightness or light intensity of the end face imaged in one real image of one end of the rod-shaped product with the brightness or light intensity of the end face imaged in another real image of the other end of the rod-shaped product.

[0020] Preferably, according to the invention, within the scope of a comparison of the brightness of one end face with the respective brightness or light intensity of the other end face, a difference between the brightness or light intensity values ​​is determined, and if this difference exceeds a predetermined level, an error signal can be generated.

[0021] The or each side of the or each rod-shaped product can be acted upon by inspection light from two different directions, in particular from directions 180° apart.

[0022] Furthermore, when inspecting a product group having multiple product layers, it may be possible to apply inspection light to the sides of the rod-shaped products of the two outer product layers of the product group (from different sides), and for the inspection light irradiated onto one outer product layer to be irradiated from a different direction than the inspection light irradiated onto the other outer product layer, particularly from a direction 180° opposite.

[0023] When one or more rod-shaped products each having a portion located outside the center of the smokable material are inspected, it may be contemplated that the inspection light beam is irradiated onto each side of each rod-shaped product such that after the inspection light beam enters the side at a first orientation of each rod-shaped product on its path to the electro-optical receiver, it does not penetrate the smokable material within the rod-shaped product or penetrates a short portion of the smokable material, but the inspection light beam penetrates the smokable material or a long portion of the smokable material within the rod-shaped product at a second orientation 180° opposite to each rod-shaped product.

[0024] Suitable devices for inspecting rod-shaped products, in particular for carrying out the method, include: at least one lighting unit is provided, from which inspection light is emitted, which is directed onto a side surface of at least one of the rod-shaped products to be inspected, preferably such that the rays of the inspection light strike the side surface at an angle of at least 30°, preferably at least 60°, particularly preferably 90°, relative to the longitudinal extent of the rod-shaped product, and the inspection light enters the rod-shaped product at least partially via the side surface and exits again at least partially via the end surface, at least one electro-optical receiver, the electro-optical receiver being arranged such that its main viewing direction is directed toward the end face of the rod-like product to detect the inspection light, thereby detecting the inspection light emerging from the end face of the rod-like product; and an evaluation unit by means of which the test light received by the electro-optical receiver can be evaluated, in particular in terms of brightness or light intensity, preferably as described above; It is characterized by:

[0025] Preferably, the inspection light is directed onto a product group consisting of rod-shaped products, the product group comprising one or more product layers of rod-shaped products each arranged side by side in a row, the opposite end faces of these rod-shaped products each constituting one of two opposite product group faces, and the lighting unit is configured so that the inspection light can be applied to the side of at least one product layer or layers, in particular the rod-shaped products of one or both outer product layers, while the product group is present in the conveyor storage section, in particular in the pocket of the rotatable turret.

[0026] More preferably, an illumination unit can be provided that applies inspection light to the side of a first outer product layer of the product group from a first side or a first direction, and applies inspection light to the side of a second outer product layer of the product group from a different second side or a different second direction.

[0027] For this purpose, the lighting unit may comprise at least two light sources, the inspection light of one light source being irradiated onto one outer product layer and the inspection light of the other light source being irradiated onto the other outer product layer.

[0028] In this case, the lighting unit may have a light-guiding unit having one or more light-guiding members, such as a mirror or a light guide, that guides inspection light emitted from one light source of the lighting unit to the side of a rod-shaped product in one outer product layer of the product group, and guides inspection light emitted from the other light source to the side of a rod-shaped product in the other outer product layer of the product group.

[0029] However, it is also conceivable that the light of one and the same light source of the lighting unit is guided by the light guide unit to both one and the other outer product layer and acts on these product layers (from different sides or from different directions).

[0030] The two light sources of the lighting unit or the at least two light-guiding members of the light-guiding unit of the lighting unit can be arranged adjacent to different sides of the product group, in particular so that the inspection light impinges on the side of the first or second product layer from different, preferably 180° opposite, directions.

[0031] Alternatively, a separate electro-optical receiver may be associated with each of the opposing end faces of a rod-shaped product or multiple rod-shaped products for detecting the inspection light emitted therefrom, in particular such that the main viewing direction of each electro-optical receiver is aligned perpendicular to the end face to which it is associated.

[0032] Each product group surface formed by the end faces of the opposing ends of the rod-shaped products can be associated with a separate electro-optical receiver for detecting inspection light emitted from all end faces of the respective product group surface, and in particular, the main viewing direction of each electro-optical receiver is aligned perpendicular to the end face of the respective product group surface.

[0033] Further features of the present invention will become apparent from the appended claims, the following description of the preferred embodiments, and the accompanying drawings. [Brief explanation of the drawings]

[0034] [Figure 1] FIG. 1 is a perspective view of a first embodiment of an inspection device according to the invention for inspecting batches of tobacco rod products positioned in the area of ​​a turret for transferring the batches; [Figure 2] Cross-sectional view along section II-II in Figure 1 [Figure 3] 1 shown in isolation, in particular a camera for detecting the product group illuminated by the lighting unit. [Figure 4a] Similar to Figure 3, but with two rod-shaped products in the same layer of the product stack, but with the wrong orientation (rotated 180°) within the stack. [Figure 4b] Similar to Figure 3, but with incorrectly oriented rods in both layers of the product stack. [Figure 5] 1 is a cross-sectional view of a first alternative embodiment of an inspection device according to the present invention; [Figure 6] 1 is a cross-sectional view of a second alternative embodiment of an inspection device according to the present invention; [Figure 7]3 of a third alternative embodiment of an inspection device according to the invention; DETAILED DESCRIPTION OF THE INVENTION

[0035] The inspection method according to the invention and the inspection device according to the invention will now be described in connection with the inspection of a group 10 of rod-shaped products, namely tobacco sticks in this case, which are transported in a receptacle 13 of a rotary conveyor 12, namely a turret in the embodiment of Figures 1 to 7.

[0036] In this case, the rod-shaped product 11 here has, in particular, a cylindrical side surface 11 and, at both ends, end faces 23 and 24 which extend transversely to the longitudinal extent of the respective rod-shaped product 11 .

[0037] The end faces 23, 24 are formed by the corresponding end faces of the filter elements 20 and 21, which are known per se.

[0038] The end faces 23, 24 or the end faces of the filter elements 20, 21 accordingly define the side faces 22 of the respective product rod 11 in the axial direction.

[0039] Between the filter elements 20, 21 or between the corresponding end faces 23, 24 of each rod product 11, there is a portion 25 having smokable material 26. The smokable material 26 may be, for example, typical tobacco or smokable liquid.

[0040] This portion 25 with the smokable material 26 is here arranged off-center with respect to a central plane of the respective rod-shaped product 11 extending perpendicular to the longitudinal axis of the rod-shaped product 11 or, correspondingly, asymmetrically with respect to this central plane.

[0041] In this example, the portion 25 is located beyond the central plane of the rod 11 and completely within one half of the rod, in particular adjacent to the filter element 21 .

[0042] In this case, the filter elements 20, 21, between which the portion 25 is arranged, have different lengths.

[0043] Additionally, between the filter elements 20, 21, further elements, here exemplarily shown as filler pieces 19, may be arranged.

[0044] The product group 10 of rod-shaped products 11 comprises a plurality of product layers 18 of rod-shaped products 11 arranged next to each other in one product layer 18. In the example of Figures 1 to 6, this is two product layers 18 each with five rod-shaped products 11 each, but this may be different.

[0045] Each product group 10 comprises a product group surface constituted by rod-shaped products 11:

[0046] A first (front) product group surface 28 is formed by the end faces 23 of the rod-shaped products 11 arranged in a common plane, and a second product group surface 29, parallel to and opposite the first product group surface 28, is formed by the end faces 24 of the other respective ends of the rod-shaped products 11, also arranged in a common plane.

[0047] The third (lower) and fourth (upper) product group faces 35 and 36 are constituted or defined by the side faces 22 of the rod-shaped products 11 .

[0048] When the orientation of the rod-shaped products 11 within the corresponding product group 10 is correct, the rod-shaped products are arranged or oriented within the product group 10 so that each similar filter element 20 or 21 is associated with the same product group surface 28 or 29, respectively.

[0049] The conveyor 12 is part of a packaging machine (not shown) known in the art for producing packs for groups 10 of rod-shaped products 11 as pack contents, respectively. Such packs may be, for example, hinge-lid packs, but also any other type of pack capable of packaging groups of rod-shaped products 11 of the cigarette or tobacco industry.

[0050] Here, the rod-shaped products 11 are fed to the conveyor 12 from the magazine 14 by a pusher while forming a product group 10.

[0051] While the batch 10 is in the receptacle 13 of the conveyor 12, it is inspected by an inspection unit 16 in a manner that will be explained in more detail below.

[0052] It will be appreciated that the illustrated inspection unit 16 may be located in a different area of ​​the packaging machine, or inspection may occur at other points in the packaging process.

[0053] Alternatively, individual inspection of the rod-shaped products 11 is theoretically possible without the need to place the rod-shaped products in a group 10 during inspection, but this is not the case.

[0054] After inspection, the product group 10 is transferred to another unit of the packaging machine for further processing, which carries out measures known per se to distribute the bar-shaped products 11 or product group 10 into corresponding packs, such as hinge-lid packs, etc.

[0055] In this example, the conveyor 13 is rotated further after each product group 10 has been inserted into a respective storage section 13 within the area of ​​the magazine 14, so that the next two product groups 10 to be inspected are now each transported to an inspection position (see Figure 2, where the product groups are inspected by the inspection unit 16).

[0056] In order to inspect the product groups to be inspected present at each inspection position in groups, the inspection unit 16 is provided with two lighting units 17, i.e., one lighting unit for each product group 10 to be inspected, which each apply inspection light to the associated product groups present at each inspection position.

[0057] In this case, the lighting units 17 each comprise suitable light sources 31, in particular LEDs, which are each supplied with power by a supply unit 32.

[0058] The light sources 31 of the lighting unit 17 in Figure 2 are each positioned adjacent to the receptacle 13 of the conveyor 12 present at each inspection position so that the inspection light beam strikes the side 22 of the rod-shaped product 11 in the outer (radially outwardly arranged) product layer 18 of the product group 10 at an angle to the longitudinal axis or longitudinal extent of the rod-shaped product 11, i.e., not parallel to the rod-shaped product, here substantially perpendicular or at a 90° angle to the longitudinal extent of the rod-shaped product 11.

[0059] For this purpose, the light sources 31 of the lighting units 17 are each positioned at radial intervals relative to the periphery of the conveyor 12, and each radial wall of each storage section 13 is provided with a (radial) opening 37 so that the side surface 22 of the rod-shaped product 11 of the outer product layer 18 can be illuminated with inspection light through the opening 37.

[0060] In addition to the illumination unit 17, the inspection device 16 here also comprises two electro-optical receivers 27, preferably cameras, which are each configured and oriented such that their main viewing direction is aligned with the end face 23 of the corresponding product group surface 28 formed by the end face of the respective product group 10 to be inspected, i.e., in this case perpendicular to the end face.

[0061] Alternatively or additionally, a further electro-optical receiver 30 may be arranged on the opposite side of the conveyor 12 or on the opposite side of the product group surface 29, with its main viewing direction being oriented in the correspondingly opposite end face 24 of the product group surface 29 (see FIG. 2).

[0062] For example, unlike the illustration shown in Figure 2, the lighting unit 17 can be configured or arranged so that the inspection light beam does not strike the side 22 of the rod-shaped product 11 perpendicularly, i.e., at a 90° angle relative to the side or longitudinal axis of the rod-shaped product 11, but at another smaller angle, i.e., obliquely relative to the longitudinal axis.

[0063] During the inspection process, the inspection light of the lighting unit 17 is directed in the manner described above to the third (lower) product group surface 35, ie to the side surface 22 of the bar-shaped products 11 of the outer product layer 18.

[0064] In this case, the rod-shaped product 11 is here illuminated with inspection light mainly in the area of ​​the (long) filter element 20, although this does not have to be the case.

[0065] The inspection light enters the rod 11, passes through the rod, is partly internally polarized, and then partly exits again through the end face 23. This part exiting the end face 23 is detected by a respective electro-optical receiver 27, which records a corresponding image in which the end face 23 is included.

[0066] Another part of the inspection light reaches another or second (disposed further radially inward) product layer 18 and partially exits again via the end face 23 of the product rod 11 and is likewise detected by a respective or the same electro-optical receiver 27. Preferably, the end face 23 of the product rod 11 of this further inner product layer 18 is included in the same image record as the end face 23 of the first outer product layer 18.

[0067] In addition, in order to improve the detection of the end faces 23 or the inspection light emerging from these end faces, further blinds 34 are arranged axially adjacent to each receiving section 13 of the conveyor 12 present at the inspection position, which blinds block scattered light not originating from the end faces 23.

[0068] The detection of rod-shaped products 11 arranged in the respective product groups 10 with incorrect orientation will first be exemplarily explained by means of Figures 3, 4a and 4b.

[0069] 3 shows a product group 10 that only comprises correctly oriented product rods 11. In this case, the product rods 11 of the product group 10 are arranged and oriented so that all (long) filter elements 20 face towards the product group face 28 and the (short) filter elements 21 face towards the opposing product group face 29.

[0070] Each electro-optical receiver 27 records an (electronic) image of the product group surface 28 or of all end surfaces 23. An evaluation unit (not shown), for example a corresponding computer or a suitably equipped control unit, then evaluates the image, for example by determining the brightness or light intensity of each end surface 23 of the product rods 11 of the product layer 18 in the image and either comparing it with stored reference values ​​or with the brightness or light intensity values, respectively, of one or more other end surfaces 23 of the product rods 11 of the same product layer 18.

[0071] Within this comparison, it can be seen that all end faces 23 in Figure 3 of the same product layer 18 each have the same or at least very similar brightness values, which is an indication that all rod-shaped products 11 within the same product layer 18 are oriented in the same correct way.

[0072] Since only one or (lower) product group surface 35 of the product group 10 is illuminated by each lighting unit 17, it will be noted that on the image of the end surface 23, the end surface 23 of the outer product layer 18 appears brighter than the end surface 23 of the inner product layer 18 because the inspection light is partially absorbed on its way to the inner product layer 18.

[0073] FIG. 4a illustrates a situation in which the outer product layer 18 contains two misoriented product rods 11a and 11b.

[0074] In this example, the evaluation of the corresponding image will result in a lower light intensity at the associated end faces 23a or 23b, since, due to the 180° rotated orientation of the rod-shaped products 11a and 11b, the test light, after entering the rod-shaped products 11a and 11b, will partially strike the respective portions 25 comprising smokable material, where the test light is more strongly absorbed than in the areas of the filter elements 20 or 21, since the filter elements are usually made very bright and have lower absorption values ​​than smokable material such as tobacco.

[0075] This lower light intensity at end face 23a or 23b compared to a reference value or to one or more of the other end faces 23 of the same product layer 18 is an indication that both rod-shaped products 11a and 11b are incorrectly oriented in the opposite direction.

[0076] Correspondingly, an error signal can be generated and the corresponding product group 10 can be separated, for example in the packaging process.

[0077] Similarly, in the correspondingly recorded image in the example of Figure 4b, it can be seen that one incorrectly oriented rod-shaped product 11a or 11b is located in each of the product layers 18 within the product group 11.

[0078] 7 shows a variation in which the product group 10 is made up of three product layers 18 instead of two. In this example, it is proposed that the (upper) product group surface 36 is also directly irradiated with the inspection light of the respective lighting unit 17, since otherwise too little inspection light would possibly enter or reach the upper product layer 18, since the inspection light would first have to pass through the lower and middle product layers 18 in FIG. 7.

[0079] Correspondingly, a further light source 31 of the lighting unit 17 is arranged directly adjacent to the upper product group surface 36, which applies inspection light directly to the upper product layer 18.

[0080] In the variation shown in FIG. 7, the three rod-shaped products 11a, 11b and 11c are misoriented, as can be seen from the end faces 23a, 23b and 23c.

[0081] 5 shows that the inspection light of each lighting unit 17 can originate from a number of light sources 31 arranged on different sides of the product group 10 and be guided to the product group 10 via a light guide element 38 of the light guide unit, here a mirror (although it is also possible to use, for example, a light guide). In that case, the light guide element 38 can be arranged in a suitable manner adjacent to the conveyor 12, so that the inspection light strikes the side of each bar-shaped product 10 of the corresponding product layer 18 in the aforementioned manner.

[0082] FIG. 6 shows that one or more light sources 31 can be integrated directly into the conveyor 12, so that the product group 10 can be directly exposed to inspection light.

[0083] In general, with regard to the inspection light generated by the lighting unit 17, it is also conceivable that the inspection light acts on possibly individual product bars 11 individually, for example by means of individual laser beams. The present application relates to the invention described in the claims, but may also include the following as other aspects. 1. A method for inspecting rod-shaped products (11), in particular tobacco sticks, from the cigarette industry, each having one particularly cylindrical side (22) and two particularly visually identical end faces (23, 24), arranged at opposite ends and particularly preferably constituted by two filter elements of different lengths, in which the rod-shaped products (11) comprise smokable material, in particular tobacco, in a portion arranged preferably off-center between the end faces (23, 24), a) irradiating a side surface (22) of at least one rod-shaped product (11) to be inspected with inspection light, in particular with the inspection light impinging on the side surface (22) at an angle of at least 30°, preferably at least 60°, particularly preferably 90°, relative to the longitudinal extent of the rod-shaped product (11), so that the inspection light enters the rod-shaped product (11) at least partially via the side surface (22) and exits again at least partially via one end surface (23, 24); b) detecting the inspection light emerging from the end faces (23, 24) of the rod-like product (11) to be inspected by means of an electro-optical receiver for the inspection light, in particular a camera, associated with the end faces (23, 24) and having a main viewing direction aligned with the end faces (23, 24); c) evaluating the test light emerging from the end faces (23, 24) and detected by an electro-optical receiver, in particular in terms of brightness or light intensity; The method of claim 1, wherein 2. 2. The method according to claim 1, wherein the brightness or light intensity of the detected test light is compared with a reference value stored in a memory or with the brightness or light intensity of the test light emerging from the other end face (23, 24) of the opposite end of the same rod-shaped product (11) or emerging from one end face (23, 24) of another rod-shaped product (11), and the side face (22) of the other rod-shaped product is irradiated with the test light so that the test light enters the rod-shaped product (11) at least partially through the side face (22) and emerges again at least partially through the end face (23, 24), and the test light emerging from the end face (23, 24) of the other rod-shaped product is detected and evaluated by an electro-optical receiver or said electro-optical receiver. 3. 3. A method according to any one or more of claims 1 to 2, characterized in that a product group (10) consisting of rod-shaped products (11) is inspected, the product group comprising one or more product layers (18) of rod-shaped products (11) each arranged side by side in a row, the end faces (23, 24) of the opposite ends of the rod-shaped products constituting one of two opposing product group faces, respectively. 4. 3. The method according to claim 3, characterized in that the side (22) of each rod-shaped product (11) of one or more product layers (18) of the product group (10), preferably of one or both outer product layers (18), is illuminated with inspection light, and the inspection light emerging from the end faces (23, 24) of at least one rod-shaped product (11) of both opposing product group faces is received and evaluated by an electro-optical receiver associated with these end faces (23, 24) or by said electro-optical receiver. 5. 5. A method according to any one or more of claims 1 to 4, characterized in that each of the opposing end faces (23, 24) of one rod-shaped product (11) or of several rod-shaped products (11) is associated with a separate electro-optical receiver for detecting the respective exiting test light, and that both the test light exiting from one of the opposing end faces (23, 24) and the other of the opposing end faces (23, 24) detected by the respective associated electro-optical receivers are evaluated. 6. 6. The method according to any one or more of claims 1 to 5, characterized in that the main viewing direction of the or each associated electro-optical receiver extends perpendicular to one or both end faces (23, 24) of the rod-shaped product (11) or rod-shaped products (11). 7. 7. The method according to any one or more of claims 1 to 6, characterized in that the or each associated electro-optical receiver is formed as a camera, in particular as a CCD camera or a CMOS camera, the or each camera records a real image, in particular a common image, of one or more end faces (23, 24), and the or each real image is evaluated. 8. 8. The method according to claim 7, characterized in that, during the evaluation of the real image, the brightness or light intensity of the end face (23, 24) of the rod-shaped product (11) imaged in the real image is compared with a stored reference value, or during the evaluation of the real image, the brightness or light intensity of the end face (23, 24) imaged in the real image is compared with the respective brightness or light intensity of at least one other end face (23, 24) of a rod-shaped product (11) of the same product layer (18) or of another product layer (18) imaged in the real image. 9. 9. The method according to claim 7 or 8, characterized in that each end face (23, 24) of the rod-shaped product (11) is associated with a separate electro-optical receiver, in particular formed as a camera, for detecting the inspection light emitted therefrom, in particular the main viewing direction of each camera is oriented perpendicular to the associated end face (23, 24), each camera records a real image of the associated end face (23, 24), and these real images are evaluated by comparing the brightness or light intensity of the end face (23, 24) imaged in one real image of one end of the rod-shaped product (11) with the brightness or light intensity of the end face (23, 24) imaged in another real image of the other end of the rod-shaped product (11). 10. 10. The method according to claim 8 or 9, characterized in that within the comparison of the brightness of one end face (23, 24) with the respective brightness or light intensity of the other end face (23, 24), a difference between the brightness or light intensity values ​​is determined and an error signal is generated if this difference exceeds a predetermined level. 11. 11. The method according to any one or more of claims 1 to 10, characterized in that the side (22) of the rod-shaped product (11) or each rod-shaped product (11) is exposed to inspection light from two different directions, in particular from directions 180° apart, or the side (22) of the rod-shaped products (11) of the two outer product layers (18) of the product group (10) are each exposed to inspection light (from different sides), with the inspection light irradiated on one of the outer product layers being irradiated from a different direction, in particular from a direction 180° apart, from the inspection light irradiated on the other outer product layer (18). 12. 12. The method according to any one or more of claims 1 to 11, characterized in that when one or more rod-shaped products (11) each having a portion of smokable material located off-center are to be inspected, each side (22) of each rod-shaped product (11) is irradiated with an inspection beam of inspection light such that the inspection beam does not penetrate the smokable material in the rod-shaped product (11) or penetrates a short portion of the smokable material after entering the side (22) at a first orientation of each rod-shaped product (11) on its way to the electro-optical receiver, but penetrates the smokable material or a long portion of the smokable material in the rod-shaped product (11) at a second orientation 180° opposite to each rod-shaped product (11). 13. 13. An apparatus for inspecting rod-shaped products (11), in particular tobacco sticks, from the cigarette industry, each having one side (22), in particular cylindrical, and two end faces (23, 24), in particular visually identical, constituted by two filter elements, particularly preferably of different lengths, arranged at opposite ends, wherein the rod-shaped products (11) comprise smokable material, in particular tobacco, in a portion arranged off-center between the filter elements, in particular in a portion arranged off-center, preferably for carrying out the method according to any one or more of 1 to 12 above, the device has at least one lighting unit (17) from which inspection light is emitted, which is preferably directed onto a side surface (22) of at least one rod-shaped product (11) to be inspected in such a way that the rays of the inspection light impinge on the side surface (22) at an angle of at least 30°, preferably at least 60°, particularly preferably 90°, relative to the longitudinal extent of the rod-shaped product (11), and the inspection light enters the rod-shaped product (11) at least partially via the side surface (22) and exits again at least partially via the end surfaces (23, 24); - at least one electro-optical receiver, the electro-optical receiver being arranged such that its main viewing direction is directed towards the end faces (23, 24) of the rod-shaped product (11) to detect the inspection light, thereby detecting the inspection light emerging from the end faces (23, 24) of the rod-shaped product (11); and an evaluation unit by means of which the test light received by the electro-optical receiver can be evaluated, in particular in terms of brightness or light intensity; A device characterized by: 14. 14. The device according to claim 13, characterized in that the inspection light is directed onto a product group (10) consisting of rod-shaped products (11), the product group comprising one or more product layers of rod-shaped products (11) each arranged next to one another in a row, the opposite end faces (23, 24) of the rod-shaped products each constituting one of two opposite product group faces, and the lighting unit (17) is configured so that the inspection light can be applied to at least one product layer (18) or a side face (22) of the rod-shaped products (11) of the product layers (18), in particular one or both outer product layers (18), while the product group (10) is present in the receiving section of the conveyor (12), in particular in the pocket of the rotatable turret. 15. The lighting unit (17) directs the inspection light emitted from the light source (31) of the lighting unit (17) to a side (22) of the first outer product layer (18) of the product group (10) and a side (22) of the second outer product layer (18) of the product group (10), or directs the inspection light emitted from the first light source (31) of the lighting unit (17) to a side (22) of the first outer product layer (18) and directs the inspection light emitted from the second light source (31) of the lighting unit (17) to a side (22) of the first outer product layer (18). The device described in claim 14, characterized in that the lighting unit (17) applies inspection light to the side (22) of the rod-shaped product (11) in the first outer product layer (18) of the product group (11) and the side (22) of the rod-shaped product (11) in the second outer product layer (18) of the product group (10), by providing a light-guiding unit having one or more light-guiding members (38), such as mirrors or light guides, that guide the inspection light to the side (22) of the second outer product layer (18) of the product group (10). 16. 16. The device described in claim 15, characterized in that the light-guiding members (38) of the light-guiding unit of the lighting unit (17) are arranged adjacent to different sides of the product group (10), in particular so that the inspection light impinges on the side (22) of the first or second product layer (18) from different, preferably 180° opposite, directions. 17. The lighting unit (17) includes two light sources (31) that are positioned adjacent to different sides of the product group (10), such that inspection light emitted from the first light source (31) of the lighting unit (17) is projected directly onto the side (22) of the first outer product layer (18), and inspection light emitted from the second light source (31) of the lighting unit (17) is projected directly onto the side (22) of the second outer product layer (18). 15. The device described in claim 14, characterized in that the lighting unit (17) applies the inspection light to the side (22) of the rod-shaped product (11) in the first outer product layer (18) of the product group (10) and the side (22) of the rod-shaped product (11) in the second outer product layer (18) of the product group (10), in particular by applying the inspection light to the side (22) of the first or second product layer (18) from different, preferably 180° opposite, directions. 18. 18. The device according to any one or more of claims 13 to 17, characterized in that a separate electro-optical receiver is associated with each of the opposing end faces (23, 24) of one rod-shaped product (11) or of multiple rod-shaped products (11) for detecting the inspection light emitted therefrom, in particular such that the main viewing direction of each electro-optical receiver is aligned perpendicular to the associated end face (23, 24). 19. 19. The device according to any one or more of claims 13 to 18, characterized in that each product group surface formed by the end faces (23, 24) of the opposing ends of the rod-shaped products (11) is associated with a separate electro-optical receiver for detecting the inspection light emitted from all end faces (23, 24) of each product group surface, and in particular, the main viewing direction of each electro-optical receiver is aligned perpendicular to the end faces (23, 24) of each product group surface. 20. 20. The device according to any one or more of claims 13 to 19, characterized in that it comprises one or more of the features of claims 1 to 12. [Explanation of symbols]

[0084] 10 product groups 11. Bar products 11a Rod-shaped products 11b Bar products 11c Bar products 12 Conveyor 13 Storage section 14 Magazine 16 Inspection Unit 17 Lighting Unit 18 product tiers 19 Filling pieces 20 filter elements 21 Filter Elements 22 Side 23 End face 23a End face 23b End face 23c end face 24 End face 25 portions 26 Smokable Materials 27 Electro-Optical Receiver 28 Front product group surface 29 Rear product group surface 30 Electro-Optical Receiver 31 Light source 32 supply units 34 Blinds 35 Product Group Surface below 36 Upper product group surface 37 Liberation Department 38 Light guide member

Claims

1. A method for inspecting rod-shaped products (11) in the cigarette industry, each having one side (22) and two end faces (23, 24) located at opposite ends, used to check the alignment of the rod-shaped products (11) in a product group (10) having one or more product layers (18), wherein the rod-shaped products (11) have smokable material between the end faces (23, 24), a) irradiating a side surface (22) of at least one rod-shaped product (11) to be inspected with inspection light so that the inspection light enters the rod-shaped product (11) at least partially through the side surface (22) and exits again at least partially through one end surface (23, 24); b) detecting the inspection light emerging from the end faces (23, 24) of the rod-shaped product (11) to be inspected by means of an electro-optical receiver for the inspection light, which is associated with the end faces (23, 24) and has a main viewing direction aligned with the end faces (23, 24); c) evaluating the test light emerging from the end faces (23, 24) and detected by an electro-optical receiver; The method of claim 1, wherein

2. 2. The method of claim 1, wherein the brightness or light intensity of the detected test light is compared with a reference value stored in a memory or with the brightness or light intensity of test light emerging from the other end face (23, 24) of the opposite end of the same rod-shaped product (11) or emerging from one end face (23, 24) of another rod-shaped product (11), and the side face (22) of the other rod-shaped product is irradiated with the test light so that the test light enters the rod-shaped product (11) at least partially via the side face (22) and emerges again at least partially via the end face (23, 24), and the test light emerging from the end face (23, 24) of the other rod-shaped product is detected and evaluated by an electro-optical receiver.

3. A method according to any one of claims 1 to 2, characterized in that the product group (10) to be inspected comprises one or more product layers (18) of rod-shaped products (11) each arranged side by side in a row, and the end faces (23, 24) of the opposing ends of these rod-shaped products each constitute one of two opposing product group faces.

4. 4. The method according to claim 3, characterized in that the side (22) of each rod-shaped product (11) in one or more product layers (18) of the product group (10) is illuminated with inspection light, and the inspection light emerging from the end faces (23, 24) of at least one of the rod-shaped products (11) on both opposing sides of the product group is received and evaluated by electro-optical receivers associated with these end faces (23, 24).

5. 5. The method according to claim 1, wherein an electro-optical receiver is associated with each of the opposite end faces (23, 24) of a rod-shaped product (11) or of a plurality of rod-shaped products (11) for detecting the respective exiting test light, and wherein both the test light exiting from one of the opposite end faces (23, 24) and detected by the respective associated electro-optical receivers is evaluated.

6. 6. The method according to claim 1, wherein the main viewing direction of the or each associated electro-optical receiver extends perpendicular to one or both end faces (23, 24) of the rod-shaped product (11) or rod-shaped products (11).

7. 7. The method according to claim 1, wherein the or each associated electro-optical receiver is configured as a camera, the or each camera records a real image of the end face or faces (23, 24), and the or each real image is evaluated.

8. 8. The method according to claim 7, characterized in that, during the evaluation of the real image, the brightness or light intensity of the end face (23, 24) of the rod-shaped product (11) imaged in the real image is compared with a stored reference value, or during the evaluation of the real image, the brightness or light intensity of the end face (23, 24) imaged in the real image is compared with the brightness or light intensity, respectively, of at least one other end face (23, 24) of a rod-shaped product (11) of the same product layer (18) or of another product layer (18) imaged in the real image.

9. 9. A method according to claim 7 or 8, characterized in that an electro-optical receiver formed as a camera is associated with each of the end faces (23, 24) of the rod-shaped product (11) for detecting the inspection light emitted therefrom, and each camera records a real image of the end face (23, 24) to which it is associated, and these real images are evaluated by comparing the brightness or light intensity of the end face (23, 24) imaged in one real image of one end of the rod-shaped product (11) with the brightness or light intensity of the end face (23, 24) imaged in another real image of the other end of the rod-shaped product (11).

10. 10. The method according to claim 8 or 9, characterized in that within the scope of a comparison of the brightness or light intensity of one end face (23, 24) with the respective brightness or light intensity of the other end face (23, 24), a difference between the brightness or light intensity values ​​is determined and an error signal is generated if this difference exceeds a predetermined level.

11. 11. The method according to claim 1, wherein the side (22) of the or each rod-shaped product (11) is exposed to inspection light from two different directions, or the side (22) of the rod-shaped products (11) of the two outer product layers (18) of the product group (10) is exposed to inspection light from different sides, with the inspection light irradiated onto one outer product layer being irradiated from a different direction than the inspection light irradiated onto the other outer product layer (18).

12. 12. The method of claim 1, wherein when one or more rod-shaped products (11) each having a portion of smokable material are to be inspected, each side (22) of each rod-shaped product (11) is illuminated with an inspection beam of inspection light such that the inspection beam does not penetrate the smokable material in the rod-shaped product (11) or penetrates a short portion of the smokable material after entering the side (22) at a first orientation of each rod-shaped product (11) on its way to the electro-optical receiver, but penetrates the smokable material or a long portion of the smokable material in the rod-shaped product (11) at a second orientation 180° opposite to each rod-shaped product (11).

13. An apparatus for inspecting rod-shaped products (11) in the cigarette industry, each having one side (22) and two end faces (23, 24) located at opposite ends, used to check the alignment of the rod-shaped products (11) in a product group (10) having one or more product layers (18), wherein the rod-shaped products (11) have smokable material between both filter elements, - at least one lighting unit (17) from which inspection light is emitted and which is directed onto a side surface (22) of at least one rod-shaped product (11) to be inspected, the inspection light at least partially entering the rod-shaped product (11) via the side surface (22) and at least partially exiting via the end surfaces (23, 24) again; - at least one electro-optical receiver, the electro-optical receiver being arranged so that its main viewing direction is directed towards the end faces (23, 24) of the rod-shaped products (11) to detect the inspection light, thereby detecting the inspection light emerging from the end faces (23, 24) of the rod-shaped products (11); and - has an evaluation unit by means of which the test light received by the electro-optical receiver can be evaluated; A device characterized by:

14. 14. The device according to claim 13, wherein the product group (10) onto which the inspection light is directed comprises one or more product layers (18) of rod-shaped products (11) arranged side by side in a row, the opposite end faces (23, 24) of these rod-shaped products respectively constituting one of two opposite product group faces, and the lighting unit (17) is configured so that the side faces (22) of the rod-shaped products (11) of the one or more product layers (18) can be acted upon by the inspection light while the product group (10) is present in the storage section of the conveyor (12).

15. The lighting unit (17) directs inspection light emitted from a light source (31) of the lighting unit (17) to a side (22) of a first outer product layer (18) of the product group (10) and a side (22) of a second outer product layer (18) of the product group (10), or directs inspection light emitted from a first light source (31) of the lighting unit (17) to a side (22) of the first outer product layer (18) and directs inspection light emitted from a second light source (31) of the lighting unit (17) to a side (22) of the first outer product layer (18).

15. The device of claim 14, wherein the lighting unit (17) is provided with a light guide unit having one or more light guide members (38) that guide the inspection light toward the side (22) of the second outer product layer (18), thereby applying the inspection light to the side (22) of the rod-shaped products (11) in the first outer product layer (18) of the product group (11) and the side (22) of the rod-shaped products (11) in the second outer product layer (18) of the product group (10).

16. 16. The device according to claim 15, characterized in that the light-guiding members (38) of the light-guiding units of the lighting unit (17) are arranged adjacent to different faces of the group of products (10).

17. 15. The device according to claim 14, wherein the lighting unit (17) comprises two light sources (31), which are arranged adjacent to different sides of the group of products (10), such that the inspection light emitted from the first light source (31) of the lighting unit (17) is cast directly onto the side (22) of the first outer product layer (18) and the inspection light emitted from the second light source (31) of the lighting unit (17) is cast directly onto the side (22) of the second outer product layer (18), thereby causing the lighting unit (17) to apply the inspection light to the side (22) of the rod-shaped products (11) in the first outer product layer (18) of the group of products (10) and the side (22) of the rod-shaped products (11) in the second outer product layer (18) of the group of products (10).

18. 18. The device according to claim 13, wherein each of the opposite end faces (23, 24) of one rod-shaped product (11) or of a plurality of rod-shaped products (11) is associated with an electro-optical receiver for detecting the inspection light emitted therefrom.

19. 19. The device according to claim 13, wherein each product group surface formed by the end faces (23, 24) at opposite ends of the rod-shaped products (11) is associated with a separate electro-optical receiver for detecting the inspection light emerging from all end faces (23, 24) of the respective product group surface.

20. A method as described in claim 1, characterized in that the end faces (23, 24) of the rod-shaped product (11) are formed by two filter elements and / or are visually identical.

21. The method of claim 20, wherein the two filter elements have different lengths.

22. The method of claim 1, wherein the smokable material is tobacco and / or is located within an acentrically located portion.

23. A method as described in claim 1, characterized in that the rays of the inspection light hit the side (22) at an angle of at least 30° or at least 60° or 90° relative to the longitudinal extent of the rod-shaped product (11).

24. A method as described in claim 1, characterized in that the inspection light is detected by a camera as an electro-optical receiver, and / or the inspection light detected by the electro-optical receiver is evaluated in terms of brightness or light intensity.

25. A method as described in claim 4, characterized in that the side (22) of each rod-shaped product (11) in one or both outer product layers (18) of the product group (10) is irradiated with inspection light.

26. A method according to claim 7, characterized in that the or each associated electro-optical receiver is formed as a CCD camera or a CMOS camera.

27. ​​The method described in claim 9, characterized in that the main viewing direction of each camera is oriented perpendicular to the associated end face (23, 24).

28. A method as described in claim 12, characterized in that one or more rod-shaped products (11) each having one portion located outside the center of the smokable material are inspected.

29. An apparatus as described in claim 13, characterized in that the end faces (23, 24) of the rod-shaped product (11) are formed by two filter elements and / or are visually identical.

30. The device of claim 29, wherein the two filter elements have different lengths.

31. The device described in claim 13, characterized in that the smokable material is tobacco and / or is located within an acentrically located portion.

32. An apparatus as described in claim 13, characterized in that the rays of the inspection light hit the side (22) at an angle of at least 30° or at least 60° or 90° relative to the longitudinal extent of the rod-shaped product (11).

33. The apparatus of claim 13, wherein the test light received by the electro-optical receiver is assessable in terms of brightness or light intensity.

34. The apparatus described in claim 14, characterized in that the product group (10) is located in a pocket of a rotatable turret.

35. The device described in claim 16, characterized in that the light-guiding member (38) is arranged so that the inspection light acts on the side (22) of the first or second product layer (18) from different directions.

36. The device described in claim 17, characterized in that the two light sources (31) are arranged so that the inspection light acts on the side (22) of the first or second product layer (18) from different directions.

37. The device of claim 18, wherein the main viewing direction of each electro-optical receiver is oriented perpendicular to the associated end face (23, 24).

38. The device described in claim 19, characterized in that the main viewing direction of each electro-optical receiver is oriented perpendicular to the end face (23, 24) of each product group surface.

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