EP1057727A1 - Method and apparatus for inspecting cigarette ends - Google Patents

Abstract

The invention relates to a method for testing cigarette heads (25, 41, 61), wherein light in at least two strip-like sections (26-31) incident from different directions onto the end face (39, 42) of a cigarette head (25, 41, 61) radiates and light (33) reflected by the end face (39, 42) is received and evaluated by a detector (32). Known methods of this type have the disadvantage that they are imprecise and do not allow exact statements about the condition of cigarettes. The invention is therefore based on the problem of improving the testing of cigarettes. This problem is solved in that, when evaluating, a distance (B, C) between two lines (54, 55, 68, 69) resulting on a signal generated to the detector (32) and corresponding to the strip-shaped sections (26-31) is determined to determine the position of the area of the cigarette head (25, 41, 61) irradiated by the sections (26-31). The invention further relates to a corresponding device. <IMAGE>

Description

The invention relates to a method for testing cigarette heads, being light in at least two different ones Strip-like sections incident on the directions Face of a cigarette head shines and from the face reflected light received and evaluated by a detector becomes. The invention further relates to a device for Testing cigarette heads with at least two light sources for illuminating a strip-like section of each Front face of a cigarette head from different directions and a detector for receiving from the face reflected light.

Test methods and test devices for non-contact are known Checking cigarette heads where one or several straight lines are blasted onto the tobacco-side cigarette head become. If the cigarette does not work properly with tobacco the line appears - if it is filled by another Viewpoint is viewed - no longer as a straight line, but as a serpentine line or as a broken serpentine line. This image is captured by a sensor. Finally be the pixels that are inside and outside a narrow Area around an imaginary, theoretical straight line, counted and related to each other. If this Ratio exceeds a limit, this should indicate that a cigarette is not properly filled.

This type of testing has the disadvantage that it is inaccurate and no exact statements about the condition of a cigarette allowed.

The invention is therefore based on the problem of testing Improve cigarettes and make more accurate statements about the condition to provide a cigarette.

The method according to the invention is to solve this problem characterized in that when evaluating a distance between two resulting from a signal generated by the detector, with lines corresponding to the strip-shaped sections is the position of the irradiated by the sections To determine the area of the cigarette head. Furthermore, that Problem solved by a device according to the invention, which characterized is for evaluation by an evaluation device a signal generated by the detector, which is formed in this way is by a distance of two resulting from the signal, lines corresponding to the strip-shaped sections to determine the position of the irradiated by the sections To determine the area of the cigarette head.

The invention makes use of the knowledge that two are on top of each other tapered light strips that act as strips of light on a Object to be measured, namely hitting a cigarette head, information about the distance of the measuring object to the measuring arrangement or another Give fixed point or generally about the position of the measurement object. The distance between the two hits the object to be measured Strip of light the desired information about the position of the Target.

This type of contactless testing of cigarette heads is suitable especially for recess filter cigarettes or papyrossi cigarettes, with these cigarettes the light streaks too on the front of the cigarette tube or the mouthpiece tube hit at least partially and also from these areas reflected light received and evaluated by the detector becomes. This gives you a point-like spot of light when Impact or cut of the light strip with the envelope or Mouthpiece sleeve. These point-like light spots provide an orientation point for the end of the cigarette or mouthpiece. The streaks of light striking the tobacco or filter lie with these cigarettes (with a hollow mouthpiece) compared to the Mouthpiece end edge back. The depth of the mouthpiece sleeve can therefore from a distance of the images of these point-like Light spots or strips of light can be determined on the detector.

The result of the test can be used to generate an error signal be used when a cigarette has predetermined limits does not comply. Such an error signal leads to the ejection of a Cigarette in the cigarette manufacturing or packaging process. A formation of several layers is preferred at the same time checked by cigarettes and, if necessary, if a faulty one occurs Cigarette ejected the entire formation.

Fig. 1

eine erfindungsgemäße Prüfvorrichtung zum Prüfen von Köpfen einer Zigarettenformation mit einer direkt vor einem Linsen-Blenden-System angeordneten Lichtquelle;

Fig. 2

einen Schnitt entlang der Linie II-II gemäß Fig. 1, der die Stirnflächen von mit Lichtstreifen beleuchteten Zigarettenköpfen einer Zigarettenformation zeigt;

Fig. 3

einen Schnitt entlang der Linie III-III gemäß Fig. 2, die die geometrische Konstruktion der einfallenden Lichtstrahlen zum Erläutern der Abstandsverhältnisse der Lichtstreifen zeigt;

Fig. 4a

das tabakseitige Ende einer korrekt ausgebildeten Zigarette im Längsschnitt;

Fig. 4b

die von zwei Lichtstreifen beleuchtete Stirnfläche des Zigarettenkopfs aus Fig. 4a, wie sie auf einem Detektor abgebildet wird;

Fig. 4c

die von einer Auswerteeinrichtung errechneten Schwerpunktslinien der Abbildungen gemäß Fig. 4b auf dem Detektor;

Fig. 5a

das tabakseitige Ende einer zu kurzen Zigarette im Längsschnitt;

Fig. 5b

die von zwei Lichtstreifen beleuchtete Stirnfläche des Zigarettenkopfs aus Fig. 5a, wie sie auf einem Detektor abgebildet wird;

Fig. 5c

die von einer Auswerteeinrichtung errechneten Schwerpunktslinien der Abbildungen gemäß Fig. 5b auf dem Detektor;

Fig. 6a

das tabakseitige Ende einer Zigarette im Längsschnitt mit einer Fehlstelle im Tabak in Form eines Lochs;

Fig. 6b

die von zwei Lichtstreifen beleuchtete Stirnfläche des Zigarettenkopfs aus Fig. 6a, wie sie auf einem Detektor abgebildet wird;

Fig. 6c

die von einer Auswerteeinnichtung errechneten Schwerpunktslinien der Abbildungen gemäß Fig. 6b auf dem Detektor;

Fig. 7a

den Zigarettenkopf einer korrekt ausgebildeten Rezeßfilterzigaretten im Längsschnitt;

Fig. 7b

die von zwei Lichtstreifen beleuchtete Stirnfläche des Zigarettenkopfs aus Fig. 7a, wie sie auf einem Detektor abgebildet wird;

Fig. 7c

die von einer Auswerteeinrichtung errechneten Schwerpunktslinien der Abbildungen gemäß Fig. 7b auf dem Detektor;

Fig. 8a

einen Zigarettenkopf einer Rezeßfilterzigarette im Längsschnitt mit schräg abgeschnittenem Filter;

Fig. 8b

die von zwei Lichtstreifen beleuchtete Stirnfläche des Zigarettenkopfs aus Fig. 8a, wie sie auf einem Detektor abgebildet wird;

Fig. 8c

die von einer Auswerteeinrichtung errechneten Schwerpunktslinien der Abbildungen gemäß Fig. 8b auf den Detektor.

Further preferred embodiments of the invention result from the subclaims and on the basis of the exemplary embodiments shown in the drawing. The drawing shows:

Fig. 1

a test device according to the invention for testing heads of a cigarette formation with a light source arranged directly in front of a lens aperture system;

Fig. 2

a section along the line II-II of Figure 1, showing the end faces of cigarette heads illuminated with light strips of a cigarette formation.

Fig. 3

a section along the line III-III of Figure 2, showing the geometric construction of the incident light beams to explain the spacing of the light strips.

Fig. 4a

the tobacco end of a properly formed cigarette in longitudinal section;

Fig. 4b

the end face of the cigarette head from FIG. 4a illuminated by two light strips, as is imaged on a detector;

Fig. 4c

the center of gravity of the images according to FIG. 4b calculated by an evaluation device on the detector;

Fig. 5a

the tobacco end of a short cigarette in longitudinal section;

Fig. 5b

the end face of the cigarette head from FIG. 5a illuminated by two light strips, as is imaged on a detector;

Fig. 5c

the center of gravity lines of the images according to FIG. 5b calculated by an evaluation device on the detector;

Fig. 6a

the tobacco end of a cigarette in longitudinal section with a missing part in the tobacco in the form of a hole;

Fig. 6b

the end face of the cigarette head from FIG. 6a illuminated by two light strips, as is imaged on a detector;

Fig. 6c

the center of gravity of the images according to FIG. 6b calculated by an evaluation device on the detector;

Fig. 7a

the cigarette head of a correctly trained recess filter cigarettes in longitudinal section;

Fig. 7b

the end face of the cigarette head from FIG. 7a illuminated by two light strips, as is imaged on a detector;

Fig. 7c

the centroid lines of the images according to FIG. 7b calculated by an evaluation device on the detector;

Fig. 8a

a cigarette head of a recess filter cigarette in longitudinal section with an obliquely cut filter;

Fig. 8b

the end face of the cigarette head from FIG. 8a illuminated by two light strips, as is imaged on a detector;

Fig. 8c

the center of gravity of the images according to FIG. 8b on the detector calculated by an evaluation device.

1 shows a test device 10 for testing a cigarette formation 11 consisting of cigarettes arranged in three layers 12. The test device 10 has two light sources 13 and 14, each preferably comprising a laser, but can also consist of another bright light source, for example an arrangement of bright LEDs. The sent out Light is therefore monochromatic and coherent or monochromatic and non-coherent or non-monochromatic and non-coherent. The light sources 13, 14 are either permanent switched on. But they can also be operated in pulsed mode, so that they produce short flashes of light.

The light rays 15 emanating from the light sources 13, 14, 16 each arrive at an optic or a lens aperture system 17, 18 or to a hologram which the Light beams 15, 16 each in three light bands 19, 20, 21 and 22, 23, 24. These light bands 19 to 24 stand out Cigarette heads 25 of the cigarettes 12. The light strips have there 19 to 24 the shape of strip-like sections 26 to 31, as shown in Fig. 2. 2 are the end faces of the cigarette heads 25 shown in FIG. 1. The cigarette formation 11 consists of three layers, the two outer ones Layers of seven and the middle layer of six cigarettes consist. Depending on the location, two strip-like sections 26 and 27 or 28 and 29 or 30 and 31 on the end faces. The each upper strip-like sections 26, 28, 30 originate from the light source 13 shown in FIG. 1 above the lower strip-like sections 27, 29, 31 originate from the lower light source 14.

Each strip-like section 26 to 31 covers a wide area the end face of the respective cigarette heads 25 and a little less than half of the face of each Cigarette head. Obtained by two strip-like sections therefore essentially an entire cover of the cigarette end face. This has the advantage that it enables an evaluation almost the entire face is possible.

Fig. 1 also shows a detector 32, which from the end faces reflected light 33 receives. The detector 32 has optics 34, which serves to reflect the reflected light 33 onto one Focus sensor. This sensor contained in the detector 32 has a CCD chip that has a variety of two-dimensional arranged CCD elements. This makes it possible the illustrations of the strip-shaped sections 26 to 31 the end faces of the cigarette heads on the CCD chip. The individual CCD elements each emit a signal that flows to an evaluation device.

The test device 10 described is preferably located on the cigarette turret of a cigarette packaging machine. she can also be arranged in a similar form on the cigarette magazine be and there a pre-sorting or an ejection of individual Cigarettes by means of an ejector arranged on the magazine make, as it / he in the German patent application DE 36 20 735 A1. At one on the cigarette revolver arranged test device leads to the detection of a faulty one Cigarette to eject the entire cigarette formation 11. For this purpose, an error signal is generated by the test device, that causes the ejector to eject.

FIG. 3 shows a section along the line III-III from FIG. 2, that is to say a longitudinal section through a cigarette head 25. This cigarette head 25 has a filter piece 35, which is opposite the end of the mouthpiece sleeve 36. The incident Light strips 20, 23 irradiate the strip-shaped sections 28, 30 at the end of the filter piece 35. Also irradiate the light strips 20, 23 also the front of the mouthpiece necks 36 at end sections 37, 38. These sections 28, 29, 37, 38 illustrate the illuminated sections at a recess filter cigarette. A similar picture would turn up result in a Papyrossi cigarette, but then the filter piece 35 is replaced by tobacco.

The lines shown in broken lines in FIG. 3 show the relationships if the cigarette is too long defective cigarette would face 39 of the filter piece 35 ends offset to the right, as well as the end Edge of the mouthpiece sleeve 40.

With a properly trained cigarette there are sections 28 and 29 at a certain distance from one another, as well as the distances 37, 38 or the distances of the sections 28 to 37 or 38 and 29 to 38 or 37. Using these Distances can be concluded from errors in the cigarette heads. Namely, as shown in Fig. 3, these sections shift 28, 29, 37, 38 away from the formation when a cigarette is too long. This moves section 28 to Line 28 'shown in dashed lines, and 29 for dashed lines line 29 'shown, as well as the end portions 37 and 38 to dashed lines 37 'and 38'.

4a shows a longitudinal section through a cigarette head 41 a tobacco-free cigarette with an end face 42. Fig. 4b shows the image obtained on the detector 32 when illuminated the end face 42 with two light strips, which as streak-like sections strike the end face 42.

On the end face 42 two images 43, 44 meet like strips Sections on that have a variety of as points Illuminate illustrated pixels 45. The one pulled out as a double circular line 46 shown is an imaginary representation of the surrounding the cigarette head 41 Cigarette paper 47. Figures 43, 44 have a medium one Section 48 or 49 on which of the respective strip-like sections illuminated tobacco-side end face areas corresponds. These middle sections 48, 49 are each delimited by two point-like end sections 50 to 53. These point-like end sections correspond to 50 to 53 bright spots of light where the light streaks hit the filter paper.

4c shows the generated or generated by an evaluation device calculated image. This picture does not necessarily have to be presented become. It is sufficient that the data on which this picture is based can be calculated to carry out the invention. From the middle Sections 48, 49 each have a line of focus 54, 55 determined. The focus lines 54, 55 are advantageous calculated so that they are parallel to each other. Moreover the end sections 50 to 53 each become a focal point 56 to 59 united.

FIG. 5a shows a cigarette as shown in FIG. 4a cigarette too short. The cigarette shown in Fig. 5a is shorter by the distance A compared to that shown in Fig. 4a. This leads to the fact that the middle sections 48, 49 are closer together than that shown in Fig. 4b. The same applies to the end sections 50 to 53. This is a consequence of the increasing distance between them tapered light strips that move together of the sections lead.

The same applies to the center of gravity shown in Fig. 5c 54, 55 and focal points 56 to 59. This shift results in a shorter distance C in Fig. 5c than a corresponding larger section B in Fig. 4c.

6a again shows the cigarette head 41 of a filterless one Cigarette, but with a piece of the tobacco filling missing. This results in a hole 60. In Figure 43 an upper one Strip of light on the detector covering an upper section of the Face of the cigarette head 41 is detected, is therefore in the upper middle section 48 in FIG. 6b to recognize an irregularity. The middle section 48 of Figure 43 is namely not essentially level, but falls off to the side. Fig. 6c shows the calculated from it Center of gravity lines 54, 55. The center of gravity line shown in Fig. 6c 54 is compared to that shown in Fig. 4c Center line 54 shifted towards the center of the cigarette.

This is a consequence of hole 60. Because the lower figure 44 in Fig. 6b corresponds to that shown in Fig. 4b, is the center of gravity 55 in Fig. 6c at the same position as in Fig. 4c. The distance between the center of gravity lines 54, 55 corresponds is no longer the target distance B according to FIG. 4c, but is compared to this smaller. This can be faulty Close cigarette. Another peculiarity of the representations 6b and 6c, it follows that the sloping section 48 in a straight line of focus 54 is converted. This computationally enforced Alignment of the center of gravity makes it easier to determine the distance focus lines 54 and 55.

7a shows the cigarette head 61 of a recess filter cigarette with a filter piece 62 and a hollow mouthpiece 63. The as stripe-like sections hitting the cigarette head 61 Streaks of light appear as Figures 64, 65 on the detector 32 shown in FIG. 7b. With such a correctly trained There are middle sections 66, 67 of the cigarette shifted towards the cigarette axis. The end sections 50 to 53 are in the same position as in Fig. 5b for a completely filled cigarette.

7c shows calculated center of gravity lines 68, 69, which are with a proper recess filter cigarette at a smaller distance are opposite the distance shown in Fig. 4c C. In addition, the focal points 56 to 59 are in Fig. 7c in a different horizontal position than the center of gravity 68, 69. This is because they are on the cigarette head 61 incident light strips or strip-shaped sections move towards the cigarette axis as these sections set back in the axial direction, i.e. in a larger one Distance to the test device.

8a again shows a cigarette head 61 of a recess filter cigarette however, the filter 62 is formed incorrectly is because it was cut off at an angle. Thereby are the middle sections 66, 67 of Figures 64, 65 at others Position in Fig. 8b compared to Fig. 7b. The end sections 50 to 53 of Figures 64, 65 are on the same Position as in Fig. 7b. 8b shows that from the illustrations center lines 68, 69 and the focal points 56 to 59. The focal points are 56 to 59 compared to Fig. 7c not shifted while the focus lines 68 and 69 in FIG. 8b shifted upwards compared to FIG. 7c are. They are also closer together on.

The differentiation between focus lines 54, 55 to 68, 69 and focal points 56 to 59 allow the determination of one or from four reference points on the edge of the cigarette case or mouthpiece sleeve. This makes statements about past Filters or holes in the tobacco are even possible in a quantitative manner, i.e. that information about distances between the end of the cigarette and any holes or the depth of a mouthpiece sleeve be made with recess filter cigarettes or papyrossi cigarettes can. For example, it can be checked whether a Mouthpiece sleeve, which has a setpoint depth of 5 mm, inside of tolerance limits of +/- 1 mm.

The test method described and the test device described allow a very high measuring accuracy. Furthermore, it is sufficient a snapshot of a cigarette head or heads a cigarette formation, the length of a cigarette, the depth of a mouthpiece sleeve, the shape of a cigarette head and to check the filling with tobacco or filter. This can a cigarette head can be measured in one motion. Thereby can - unlike other known test methods in which for example, a plunger pressed onto a cigarette head through this non-contact process at high speed a cigarette packaging or manufacturing machine operate. The invention therefore opens one Variety of options when testing cigarette heads.

Reference symbol list :

10th

Tester

11

Cigarette formation

12th

Cigarette

13

Light source

14

Light source

15

Beam of light

16

Beam of light

17th

Lens aperture system

18th

Lens aperture system

19th

Light band

20th

Light band

21

Light band

22

Light band

23

Light band

24th

Light band

25th

Cigarette head

26

strip-like section

27

strip-like section

28

strip-like section

28 '

strip-like section

29

strip-like section

29 '

strip-like section

30th

strip-like section

31

strip-like section

32

detector

33

reflected light

34

Optics

35

Filter piece

36

Mouthpiece sleeve

37

end section

37 '

end section

38

end section

38 '

end section

39

Face

40

Mouthpiece sleeve

41

Cigarette head

42

Face

43

Illustration

44

Illustration

45

pixel

46

circular line

47

Cigarette paper

48

middle section of the Illustration

49

middle section of the Illustration

50

End section

51

End section

52

End section

53

End section

54

Center of gravity

55

Center of gravity

56

main emphasis

57

main emphasis

58

main emphasis

59

main emphasis

60

hole

61

Cigarette head

62

Filter piece

63

Mouthpiece

64

Illustration

65

Illustration

66

middle section of the Illustration

67

middle section of the Illustration

68

Center of gravity

69

Center of gravity

A

distance

B

distance

C.

distance

Claims (14)

Method for testing cigarette heads (25, 41, 61), wherein light shines in at least two strip-like sections (26-31) incident from different directions onto the end face (39, 42) of a cigarette head (25, 41, 61) and from it Front surface (39, 42) of reflected light (33) is received and evaluated by a detector (32), characterized in that during the evaluation a distance (B, C) between two resulting from a signal generated by the detector (32) with the strip-like sections (26-31) corresponding lines (54, 55, 68, 69) is determined in order to determine the position of the region of the cigarette head (25, 41, 61) irradiated by the sections (26-31). Method according to Claim 1, characterized in that images of the strip-shaped sections (26-31) received by the detector (32) are subjected to image processing, with a center of gravity line (54, 55, 68, 69) per image of a strip-shaped section (26-31) ) is determined as a corresponding line, in particular is calculated. Method according to Claim 2, characterized in that the centroid lines (54, 55, 68, 69) are calculated in such a way that they run parallel to one another. Method according to one of Claims 1 to 3, characterized in that an error signal is generated when the determined distance exceeds or falls below a limit value, in particular by an ejector for ejecting a tested cigarette (12) or a cigarette formation containing this cigarette (12) (11) to activate. Method according to one of claims 1 to 4, characterized in that the strip-shaped sections (26-31) illuminate essentially the entire end face (39, 42), in particular the tobacco or filter end face, of the cigarette (12). Method according to one of claims 1 to 5, characterized in that a strip-shaped section (26-31) covers several, in particular six or seven, cigarettes arranged next to one another in one layer of a cigarette formation (11) and one of the number of layers of the cigarette formation from each direction (11) corresponding number of strip-shaped sections (26-31), in particular three, are blasted onto the end faces (39, 42). Method according to one of claims 1 to 6, characterized in that the detector (32) receives light (33) reflected in the axial direction to the cigarette axis and the incident light (19-24) from two directions arranged at equal angles to the cigarette axis on the end face (39, 42) is blasted. Method according to one of claims 1 to 7, characterized in that both cigarette heads (25, 41, 61) of a cigarette (12) are checked and the cigarette length is calculated from the positions obtained. Method according to one of claims 1 to 8, characterized in that the strip-shaped sections (26-31) the front side of the cigarette wrapper, in particular the cigarette paper surrounding the cigarette (12), and / or the mouthpiece sleeve (63) of a recess filter cigarette or papyrosic cigarette, partially illuminate and the light (33) reflected from this end face is received and evaluated. Method according to Claim 9, characterized in that a distance between a center of gravity (56-59) of an image (50-53) of the illuminated areas (37, 38) of the cigarette casing and a center of gravity line (54, 55) is calculated by the depth to close a mouthpiece sleeve (63) or the depth of a tobacco defect (60) and / or to calculate a distance between two focal points (56-59) of two images (50-53) of two illuminated areas (37, 38) of the cigarette case Formation of the cigarette case, especially to check its uniformity. Device for testing cigarette heads (25, 41, 61) with at least two light sources (13, 14) for illuminating in each case a strip-like section (26-31) of an end face of a cigarette head (25, 41, 61) from different directions and a detector ( 32) for receiving light (33) reflected from the end face, characterized by an evaluation device for evaluating a signal generated by the detector (32), which is designed such that a distance between two resulting from the signal with the strip-shaped sections (26- 31) to determine corresponding lines (54, 55, 68, 69) in order to determine the position of the region of the cigarette head (25, 41, 61) irradiated by the sections (26-31). Apparatus according to claim 11, characterized by a lens aperture system (17, 18) assigned to a light source (13, 14) and / or an optical system with a hologram for producing the strip-like sections (26-31), in particular one of the number the number of layers corresponding to a formation (11), in particular three, strip-like sections (26-31), one strip-like section (26-31) each being directed to one layer. Device according to claim 11 or 12, characterized by pulsed light sources (13, 14), in particular laser or LED light sources, for generating flashes of light. Device according to one of claims 11 to 13 for performing of a method according to one of claims 1 to 10.

Images