WO2006021261A1

WO2006021261A1 - Optical control of products in the tobacco processing industry

Info

Publication number: WO2006021261A1
Application number: PCT/EP2005/007223
Authority: WO
Inventors: Wolfgang Siems
Original assignee: Hauni Maschinenbau Ag
Priority date: 2004-08-23
Filing date: 2005-07-05
Publication date: 2006-03-02
Also published as: CN101006335B; JP2008510973A; US20070137661A1; CN101006335A; EP1782047A1; DE102004040912A1

Abstract

The invention relates to a device for the optical control of products (64) in the tobacco processing industry, comprising an image recording unit (41 - 43, 60, 63, 65). The inventive device is characterised in that the image recording unit (41 - 43, 60, 63, 65) comprises at least one gradient index lens (60). The invention is also characterised by the use of a gradient index lens (60) for the optical control of products (64) in the tobacco processing industry.

Description

Optical control of tobacco industry products

description

The invention relates to the optical control of products of the Ta bak processing industry and a device for optical control of such products comprising a Bildfassungsvor- direction.

In the context of this invention, products of the tobacco-processing industry include in particular rod-shaped and strip-shaped products or objects such as cigarettes, filter rods, multisegment filter rods, cigarette or tipping paper and stamp imprints

Paper webs or glue on paper webs understood. In optical control, quality features are usually detected on the products of the tobacco processing industry, such as holes, lengths, object identification, stamps, glue application, spot dimensions, the presence of filter elements, damage, etc. For optical control, line or matrix cameras are usually used, which are equipped with elaborate, large lenses because of the requirement for imaging and resolution quality. For example, to consider the entire cigarette length without distortion and deterioration of sharpness, a considerable distance of the measurement object to the camera is necessary. At some points of a machine of the tobacco processing industry, such as a filter attachment machine, it is necessary that the optical path with mirrors be folded several times. At many

Providing a filter attachment machine is also an optical control due to geometric requirements in this machine is not given.

The illumination of the measurement objects or products of the tobacco processing industry is realized with separate light sources, which must have high light intensities because of the large distance to the object. It is also known, among other things, to introduce the light under intensity losses with optical cables to the test object. The probability that flying particles such as tobacco dust interfere with the optical control and it comes to incorrect ratings is large and can be reduced only by aufwendi¬ ge measures because of the large Ab¬ state of the control devices used.

In contrast, it is an object of the present invention to provide a compact design device for optical control of products of the tobacco-processing industry and basically to reduce interference in the optical control of such products.

This problem is solved by the use of a gradient index lens for the optical control of products of the tobacco processing industry.

In the context of the invention, a gradient index lens is a light-transmissive element which causes a lens effect as a result of a continuous change in refractive index. Instead of partially complicated shaped surfaces in conventional lenses, the light beams preferably enter planar surfaces. The light rays are continuously deflected in the gradient index lens and finally focused in one focal point. In this case, the refractive index is preferably varied transversely to the optical axis. The gradient index lenses can be made very compact and in particular with a very small diameter. Furthermore, the lens length is variably adjustable and, above all, the focal length and the working distance can be very close to the

Ends of Gradientenindexlinse be introduced. By way of example, the image plane can lie directly on the planar surface of the lens by means of a suitable choice of the lens length, so that light sources can be glued directly onto the lens. In particular, it is also possible to design or arrange the focal length to the product to be optically controlled very close to the preferably planar surface of the gradient index lens, so that due to the close proximity of the lens to the product to be controlled only few particles can interfere with the control, since only a few particles have space in the distance between the lens and the product to be measured or controlled.

The invention is particularly effective if a plurality of gradient index lenses arranged next to one another, in particular in at least one row, are used. In this case, rod-shaped and strip-shaped objects can be controlled for quality and other properties in a simple manner. If In addition, for the illumination of the products of the tobacco processing industry, a Gradientenindexlinse use, and the part of the optical control device can be made physically small, which ensures the lighting of the products. Particularly effective illumination is given when a plurality of gradient index lenses arranged side by side, in particular in a row, are used for illumination.

The object is furthermore achieved by a device for the optical control of products of the tobacco-processing industry comprising an image acquisition device, the image acquisition device comprising at least one gradient index lens. Such a device can be realized in a very space-saving manner because of the very small gradient index lens and because of the very short adjustable focal lengths or distances of the respective ends of the gradient index lens to the focal points. The image acquisition device preferably comprises a plurality of gradient index lenses arranged side by side, in particular in a row. As a result, rod-shaped and strip-shaped objects or products can be controlled very effectively.

If the image acquisition device also comprises a line of photodiodes or a CCD line, a simple and also space-saving recording or recording of the images of the objects or products of the tobacco-processing industry is possible. A

CCD line is known per se. The abbreviation CCD comes from the well-known term Charged-Coupled Device. In particular, special CCDs are used in this invention in which one half of the elements provided in the CCD converts an image focused on the surface pointwise into intensity-dependent charge quantities, while the other half serves to store and read out the information. In this respect, the CCDs as Image sensors used.

Preferably, the image capture device comprises a Vorrich¬ device for comparing the captured images with predetermined images. As a result, an efficient visual inspection of the products is possible. For example, in the control of filters or filter belts, a proper filter or a proper filter cigarette can be stored and compared with the captured image of the filter to be controlled or the filter cigarette to be controlled. Particularly efficient is a control of

Multisegmentfiltem possible. If, for example, there is too great a difference in intensity distribution, then the correspondingly controlled products can be eliminated from further processing. The device for comparing the acquired image with predeterminable images is preferably a computer which stores the predefinable image (s) in a storage element and by means of which a comparison of this image with the acquired images is possible Subsequently, a control signal can be generated, which represents a proper product or a product to be claimed.

If a lighting device with a light source and at least one gradient index lens which guides a light from the light source to the product to be controlled is provided, this can also be realized in a very space-saving manner. The illumination is particularly effective if a plurality of gradient index lenses arranged side by side, in particular in a row, are provided.

In the context of this invention, an arrangement nebeneinan¬ means, in particular in a row, the arrangement in an array according to the Fig. 3, which will be described below. loading The device according to the invention can be used particularly effectively if the focus of the gradient index lens is arranged at the end or in the immediate vicinity of the end of the gradient index lens. As a result, measuring inaccuracies or incorrect evaluations by flying particles such as tobacco dust can be largely avoided.

Preferably, a machine of the tobacco-processing industry comprises a device according to the invention for the optical control of products of the tobacco-processing industry.

In a particularly preferred embodiment, in the machine of the tobacco-processing industry, the products, in particular filter rods or cigarettes, can be guided transversely axially past the plurality of gradient index lenses arranged next to one another.

The invention will be described below without limiting the general idea of the invention by means of exemplary embodiments. With regard to all the details of the invention which are not explained in greater detail in the text, reference is expressly made to the drawings. Show it:

1 is a schematic side view of a Filteransetzma¬ machine,

2 shows a schematic representation of the mode of operation of a gradient index lens,

FIG. 3 is a schematic broken view of a gradient index lens element, and FIG

4 is a schematic sectional view through a FiI- rod and two Kontrollinrichtun¬ invention.

1 shows a schematic side view of a filter attachment machine in essential parts. The filter attachment machine, for example of the MAX type of the applicant, comprises a transfer drum 2 on which double-use-length cigarettes produced by a cigarette-making machine have been transferred. Next, the double-use-length cigarette rods are fed to a tobacco rod cutting drum 3, which cuts the tobacco rods into two pieces of tobacco of simple use length. After cutting the tobacco rod, the tobacco sticks are fed to a spreading drum 4, by means of which the tobacco sticks are spread apart in such a way that filter elements find space therebetween. The thus spread tobacco sticks are fed to a feed drum 5. The feed drum or feed drum 5 are also fed with filter elements, specifically these are inserted between the tobacco sticks on the feed drum 5 into the corresponding receptacles of the feed drum 5. For this purpose, first, what is not shown in FIG. 1, by means of a cutting, removal and cutting drum 6 Filterele¬ elements taken from a filter element stock. With regard to the removal of filter elements from a filter element supply, reference is made to DE 25 05 998 C2, which corresponds to US Pat. No. 4,020,973. In this case, for example, multiple filter elements can be used which have the corresponding filter components, which are not shown, in 16 times the useful length.

On the cutting drum 6, these are first cut twice by means of circular knives 10 in multifilter segments 4 times the length of use. In the staggering drum 7, these multifilter segments are staggered, in order to align them initially in the sliding and cutting drum 8 in a cross-axial direction, and To cut a circular blade 10 in multi-segment filter sections twice the useful length. Subsequently, the filter elements on the sliding and cutting drum 8 are aligned again in order to be cut again by a circular knife 10 in multifilter segments of simple use length. These will be on one

Transfer drum 11 and transferred by means of a Beschleuniger¬ drum 12 to the feed drum 5, so that the multi-segment filter elements simple use length on the inside of the tobacco sticks. Another filter element 12 times the use length is by means of the cutting drum or cutting

/ Removal drum 15 taken in a known manner from a filter supply (see as above already DE 25 05 998 C2, which corresponds to US 40 20 973). On the cutting drum 15, these filter sections are cut twice by circular knives 10 in order to be transferred to a staggering drum 16. These filter segments are then, after being staggered, transferred to a sliding and cutting drum 17, where they are aligned transversely aligned and cut twice, so that filter elements Ein¬ times use length arise. Subsequently, the filter elements of simple useful length are staggered in a staggering drum 18 in order to be transferred to a sliding drum 19, in which they are pushed together in a longitudinally axial alignment. A further accelerator drum 13 serves to insert the filter elements in the middle of the respective receptacles. In this exemplary embodiment, the last-mentioned filter elements of simple useful length are first inserted into the middle of the receptacles of the feed drum 5, in order to subsequently arrange the further filter elements of simple use length around them and then to arrange the respective tobacco sticks completely outside.

The thus assembled tobacco rod / filter element / tobacco rod groups or cigarette filter cigarette groups then become a transfer drum 21 fed. At this point, then the first optical control is performed. For this purpose, the first control device 41, which measures or checks in a reflected-light technique or in reflection, whether the filter components are complete, whether the position of the filter components is correct, whether the length of the individual components is correct and if so whether Brightness deviations of individual filter components are detectable. The configuration of the first control device will be described with reference to the other figures.

The corresponding compiled tobacco rod / filter element / tobacco rod sections are then transferred to a feed drum 22 in order to be pushed together in an alignment drum 23. A tipping paper strip 52 drawn off from a tipping paper bobbin 50 or 51 is glued by a gluing device and then cut in a cutting device 53 on a cutting drum 54 by the knives of a knife drum 53 into covering laminae. The separated pad sheets are adhered to the cigarette filter-cigarette groups on the alignment drum 23 and rolled around the cigarette filter groups on a roller drum 24. For this purpose, a rolling hand 27 and an accordingly thereto an¬ closing acceleration element 26 in a known manner.

The finished double-filter cigarettes are fed via a transfer drum 28 or a drying drum 28 to a cutting drum 29 and are made up into single-filter cigarettes thereon by cutting them centrally through the filter plugs. The single filter cigarettes are then transferred to a transfer drum 31. In this transfer drum 31 and in this transfer drum 31, a further measuring device 42 is provided which determines in a Auf¬ lichtverfahren whether the tipping paper edge is in the correct position and whether the tipping paper imprint is performed correctly. With respect to these measurements to be made, reference is also made to what has been described below.

Subsequently, a turning drum 32 turns a series of filter cigarettes and at the same time transfers them into the continuous untyped series of filter cigarettes. By means of a test drum 33, which is described, for example, in DE 35 17 155 C2, which corresponds to US Pat. No. 4,662,214, the filter cigarettes reach an ejection drum 34. On the ejection drum 34 or at least partially in the ejection drum 34 There is a third control device 43 which monitors, for example, the side of the cigarette turned away from the second control device 42 for faults, cracks or general quality characteristics.

Subsequently, the filter cigarettes pass into a transfer drum 36 and a blow-out drum 37, in which cigarettes can be removed randomly by means of a removal drum 38. The non-removed filter cigarettes reach a Ableger¬ drum 39 which deposits the filter cigarettes in a known manner on a Ablegeband to er¬ testify a mass flow of filter cigarettes. The generation of a mass flow and a corresponding device in this respect are described, for example, in EP 0 692 201 B1.

FIG. 2 shows a schematic representation of a gradient index lens 60. In the case of a gradient index lens 60, the refractive index is configured differently or variably transversely to the optical axis. This is indicated by different gray shades in FIG. 2. The different refractive indices across the optical axis create a lens effect.

For this reason, as in the embodiment of Fig. 2, light beams 61 will pass through the gradient index lens 60 focused in a Focus 62. The focus 62 is relatively close to the one end of the gradient index lens. This focus can also be adjusted so that it is arranged exactly on an end face of the gradient index lens 60. If, for example, a surface of a cigarette or the surface of a cigarette filter is arranged in the focus 62, there is little space between the gradient index lens 60 and the surface of the cigarette, so that little material can stay between these two elements, which leads to fewer disturbances in the measurement or control of the respective products. In addition, an airflow curtain can serve to prevent corresponding disturbing Mate¬ rial.

In order to measure products extending in a longitudinal axis effectively and quickly, such as, for example, rod-shaped or strip-shaped

Objects (for example, cigarettes in the filter attachment machine, glue application and a stamp imprint on paper webs and der der same), it is preferred to use a lens element 63 of FIG. 3. In FIG. 3, a corresponding lens element 63, which consists of an array of gradient index lenses 60, is illustrated diagrammatically and in three dimensions. In the context of the invention, the term row can also be used instead of the array. In this case, a double row of gradient index lenses 60 is shown.

FIG. 4 shows a sectional view of a corresponding measurement arrangement or control arrangement. There are two devices for optical control, each comprising a Gradienten¬ index lens 60, for receiving an image of a quarter surface of a cigarette filter 64 includes and two Gradientenindexlinsen

60 ', which focus the light from each of a light emitting diode line 66 to the location of the cigarettes 64, taken from the one picture shall be. The corresponding beam paths or light beams 61 are also indicated.

In the arrangement according to FIG. 4, in which the cigarettes 64 move past in the direction of the arrow at the control point or the measuring point, that is to say transaxially, i. transverse to the longitudinal axis of the cigarettes 64, only one half of the cigarettes 64 is optically controlled. The other half can be controlled in another place, if, for example, the cigarettes 64 are arranged the other way around in a trough of a receiving drum. The CCD used in FIG. 4

Rows receive corresponding to the area of the surface of the cigarettes 64 to be controlled. There is also provided a computer 70, shown in FIG. 1, which compares the captured image to a presettable and / or stored image, the stored image corresponding to the target state of the surface of the image

Cigarettes 64 can represent. If the recorded image, which was obtained by the respective CCD line 65, corresponds to the stored image or differs therefrom in a corresponding tolerance range, the cigarette 64 is conveyed on normally in the machine, for example according to FIG , If the optical control determines that the cigarette 64 is faulty, it is ejected, for example, in the removal drum 38. In FIG. 1, an electrical connection of the computer 70 to the control devices 41 to 43 is indicated by dashed lines.

The invention provides a compact optical inspection system with high optical resolution. In particular, an object surface with a series of gradient index lenses is imaged on a line of photodiodes or a CCD line. The illumination of the object surface is also preferably done with a series of Gradientenindexlinsen. The use of this compact The optical surface inspection system or the compact optical control device on cigarette, filter machines and filter attachment machines is preferred because of its compact design.

The imaging does not occur by conventional lens systems but by a juxtaposition of Gradientenindexlinsen on a line of photodiodes or a CCD line. In addition to the compact design, the high optical quality and resolution is advantageous and that the gradient index lens rows can be modularly arranged one on the other. Flying particles that might affect the control result may pass through a small barrier air curtain due to the proximity of the object or product surface to the gradient index lens or gradient index lens array, which is in the range of a few millimeters near the object surface or product surface be held. The illumination can also be integrated compactly by an LED row parallel to the receiver diode array in the optical control device. The light generated by the LED line can be bundled onto the object surface by means of a row or row of gradient index lenses.

LIST OF REFERENCE NUMERALS

1 filter attachment machine

2 transfer drum

3 tobacco rod cutting drum

4 spreading drum

5 feed drum

6 cutting drum

7 season drum

8 sliding and cutting drum

10 circular knives

11 sliding drum

12 accelerator drum

13 accelerator drum

15 cutting drum

16 relay drum

17 sliding and cutting drum

18 relay drum

19 relay drum

21 transfer drum

22 feed drum

23 alignment drum

24 roller drum

26 acceleration element

27 roll hand

28 transfer drum

29 cutting drum

31 transfer drum

32 beater

33 test drum

34 ejection drum

36 transfer drum 37 blower drum

38 removal drum

39 Ablegertrommel

41 1. Control device

42 2. Control device

43 3. Control device

50 Bobine

51 Bobine

52 tipping paper

53 Tipping paper cutter

54 Coating paper drum

0 'gradient index lens

61 light beam

62 Focus

63 lens element

64 cigarette

65 CCD line

66 light-emitting diode lines

70 computers

Claims

Optical control of tobacco industry products

1. Use of a gradient index lens (60) for optical control of products (64) of the tobacco-processing industry.

2. Use according to claim 1, characterized in that a plurality of juxtaposed, in particular in wenigs¬ least one row (63), arranged Gradientenindexlinsen (60) are used.

3. Use according to claim 1 or 2, characterized gekennzeich¬ net, that also for illuminating the products (64) of the tobacco-processing industry, a Gradientenindexlinse (60) is used.

4. Use according to claim 3, characterized in that a plurality of juxtaposed in one, in particular in a row (63), gradient index lenses (60) are used for illumination.

5. Device for visual inspection of products (64) of

Tobacco-processing industry comprising an Bildfassungsvor¬ direction (41-43, 60, 63, 65), characterized in that the Bil¬ sensing device (41-43, 60, 63, 65) at least one gradient index lens (60).

6. Device according to claim 5, characterized in that the image acquisition device (41-43, 60, 63, 65) comprises a plurality of juxtaposed, in particular in a row (63), Gradientenindexlinsen (60).

7. Device according to claim 5 or 6, characterized gekennzeich¬ net, that the image sensing device (41 - 43, 60, 63, 65) also comprises a line of photodiodes (65) or a CCD line (65).

8. Device according to one or more of claims 5 to 7, da¬ characterized in that the image capture device (41 - 43, 60, 63, 65) comprises a device for comparing the captured image with predetermined images.

9. Device according to one or more of claims 5 to 8, da¬ characterized in that a lighting device (60 ', 66) with a light source (66) and at least one light (61) from the light source (66) to be controlled Product (64) conductive Gradientenindexlinse (60 ') is provided.

10. Device according to claim 9, characterized in that a A plurality of side by side, in particular in a row (63) an¬ graded index lenses (60 ') are provided.

11. Device according to one or more of claims 5 to 10, characterized in that the focus (62) of the Gradientin- dexlinse (60) to be controlled product (64) at the end or in the immediate vicinity of the end of the Gradientenindexlinse (60) is.

12. machine (1) of the tobacco processing industry with a Einrich¬ device (41 - 43) for optical control of products (64) of the tobacco processing industry.

13. Machine (1) according to claim 12, characterized in that in this the products (64) of the tobacco processing industry, in particular filter rods (64) or cigarettes, transversely to the plurality of juxtaposed Gradientenindexlinsen (60, 60 ') are passable.