JP2017080996A - Deviation detection device and deviation correction device, and deviation detection method and deviation correction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to directly detect a deviation between marginal parts of two films superposed in a bag making machine and suppress such a deviation.SOLUTION: A deviation detection device comprises: illumination means 621, 622 which radiate superposed two films 921, 922 with light; first and second imaging parts 611, 612 which pick up images of said two films from a vertical direction and generate a first image and a second image respectively; and detection means 6 which specifies marginal part images of two films in each image, and which determines whether two marginal part images are present or not in at least one image of the first and the second images.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a deviation detection device and a deviation correction device, and a deviation detection method and a thread correction method for an edge (edge) of two superimposed films, and more specifically, an edge of two superimposed films. The present invention relates to a deviation detecting device and a deviation correcting device for correcting the deviation in a bag making machine, and a deviation detecting method and a thread correcting method.

  Conventionally, a bag-like container formed of a soft wrapping material such as a film is often used as a container containing foodstuffs or liquid detergent as a content. In general, such a bag-like container is manufactured from a flexible plastic film by a bag making machine. For example, in the flat bag three-way bag making machine, the film fed from the original fabric roll is cut in half along the flow direction, and then the two films after the half cut are overlapped to perform bottom sealing and side sealing, Subsequently, a bag-like container having three sides sealed and having an opening on one side is manufactured by cutting at the seal portion.

  With respect to such a bag making machine, various improvements have been proposed for the purpose of improving the productivity and quality of bags to be manufactured. For example, Patent Document 1 below discloses a technology for automatically and effectively automatically correcting a seal position and a cutting position with respect to a print pitch shift or film meandering by detecting an eye mark printed on a film. It is disclosed.

JP 2008-1000046 A

  In the bag making machine, there may be a phenomenon of meandering in which one or both of the two conveyed films are shifted in the width direction perpendicular to the flow direction. When the film meanders, the positions of the edges of the two films are shifted from each other, and if they are overlapped and sealed as they are, a lip shift (edge shift) may occur at the opening of the manufactured bag-like container. There is. Therefore, in the above-mentioned Patent Document 1, the positional deviation of the edge portions of the upper and lower films due to the meandering of the film is detected by detecting the eye mark printed on the film.

  However, if it is possible to detect the relative shift between the edges of the two films without printing an eye mark on the film, it is more desirable because the restrictions on the printing plates of the films can be relaxed. Further, it is required to further prevent the occurrence of lip deviation.

  The present invention has been made in view of the above circumstances, and a deviation detection device and a deviation correction device capable of directly detecting the relative deviation between the edges of two films superimposed in a bag making machine, An object of the present invention is to provide a deviation detection method and a deviation correction method.

  In order to achieve this object, the shift detection device of the present invention is a shift detection device that detects the shift of the edges of two superimposed films, and illuminating means for irradiating the two films with light, First imaging means for capturing an image of an edge of the two films from the surface side of one of the two films to generate a first image, and a surface of the other film of the two films A second imaging unit that images the edge from the side to generate a second image, and a detection unit that detects a relative shift between the edges of the two films based on the first and second images; The detection means identifies an edge image of the two films in the first and second images, and whether or not two edge images exist in at least one of the first and second images. It is characterized by judging.

  Moreover, the deviation correction apparatus of this invention is an apparatus which corrects the deviation of the edge overlapped in the bag making machine, and the detection means in the deviation detection apparatus described above is (1) one of the first and second images. When it is determined that the two edge images are present only on one side, the film edge on the back side as viewed from the imaging means of the image determined to have the two edge images is more than the film edge on the near side. Or (2) when it is determined that the two edge images are present in the first and second images, respectively (2-1) in the first and second images. According to the comparison result of the brightness of the predetermined image, it is determined which of the two films is shifted outward, or (2-2) the brightness of the predetermined image in the first or second image is determined. Larger than the threshold value It is a detection means for determining which of the two films is shifted outward by determination, and when the detection means determines that there are two edge images, the two edge images in the one image The distance between the two films is determined based on the measured distance, and the positional deviation between the two films and the positional relationship between the two films is determined. And a correcting means for correcting the position in the width direction perpendicular to the flow direction of one or both of the two films.

Further, the deviation detection method of the present invention is a deviation detection method for detecting the relative deviation between the edges of two superimposed films, an illumination step of irradiating light on the two films, and two sheets A first imaging step of capturing an image of an edge of two films from the surface side of one of the two films to generate a first image, and an edge from the surface of the other film of the two films A second imaging step of capturing a part and generating a second image, and a detection step of detecting a shift between the edges of the two films based on the first and second images. Identifying the edge images of the two films in the first and second images, and determining whether there are two edge images in at least one of the first and second images. And a step.
Further, the deviation correction method of the present invention is a method for correcting a deviation between the edges of two overlapped films in a bag making machine, wherein the deviation of the film edge detected by the deviation detection method described above is detected by the two films. The correction is performed by correcting the position in the width direction perpendicular to the flow direction of one or both of the films.

  According to the present invention, it is possible to directly detect and correct the relative shift between the edges of two superimposed films. Thereby, in a bag making machine, a lip shift can be suppressed.

It is the schematic for demonstrating the structure of the bag manufactured with a bag making machine, (i) is a top view of a bag, (ii) is a bottom view of a bag, (iii) is drawn out from the original fabric. (Iv) is a plan view of the upper and lower films in which the film shown in (iii) is cut in half. It is a top view of a bag making machine. It is a front view of the bag making machine shown in FIG. 1 is a perspective view of a deviation detection device according to a first embodiment of the present invention. It is sectional drawing of the upper and lower films with which the edge part was aligned, and the side view of a detection apparatus. FIG. 6 is a first image of the upper and lower films in FIG. 5 taken from the upper side by the first imaging means. FIG. 6 is a second image of the upper and lower films in FIG. 5 taken from the lower side by the second imaging means. It is sectional drawing of the upper and lower films from which the edge part of the lower film shifted | deviated outside the edge part of the upper film, and the side view of a detection apparatus. It is a 1st image of the upper and lower films of FIG. 8 imaged from the upper side by the 1st imaging means. It is the 2nd image of the upper and lower films of FIG. 8 imaged from the lower side by the 2nd imaging means. It is sectional drawing of the upper and lower films from which the edge part of the upper film shifted | deviated outside the edge part of the lower film, and the side view of a detection apparatus. It is a 1st image of the upper and lower films of FIG. 11 imaged from the upper side by the 1st imaging means. It is the 2nd image of the upper and lower films of FIG. 11 imaged from the lower side by the 2nd imaging means. It is AA sectional drawing of FIG. It is a top view of the meandering upper film and lower film. It is a flowchart for demonstrating the deviation | shift detection method. It is a flowchart which shows the procedure of the shift | offset | difference detection process in 1st embodiment. It is a flowchart which shows the procedure of a deviation correction process. It is a 1st image of the upper and lower films of FIG. 8 imaged from the upper side by the 1st imaging means. It is the 2nd image of the upper and lower films of FIG. 11 imaged from the lower side by the 2nd imaging means. It is a flowchart which shows the procedure of the shift | offset | difference detection process in 2nd embodiment. It is a side view of the shift | offset | difference detection apparatus provided in the bag making machine which concerns on 3rd embodiment of this invention.

[First embodiment]
A first embodiment of a deviation detection apparatus and method and a bag making machine according to the present invention will be described.
Here, prior to the description of the deviation detection device, referring to FIGS. 1 to 3, a bag-like container (also simply referred to as a bag) manufactured from two films as examples of deviation detection, and the bag A bag making machine to be manufactured will be described.

<Bag-like container>
The manufactured bag-like container (bag) 10 shown in FIG. 1 (i) and FIG. 1 (ii) is called a flat bag, and a rectangular front side film 11 and a back side film 12 are overlapped, A bottom seal 13 is applied to the bottom edge, a pair of side seals 14 is applied to the left and right edges, and the top is opened without being sealed. Further, chamfered portions 16 are formed at the four corners of the bag 10 and notches 17 are formed at the side edges. Further, a front print 18 that is typically displayed as “F” is applied to the surface of the front film 11, and a back print 19 that is schematically displayed as “b” is applied to the surface of the back film 12. Has been.

<Bag making machine>
Next, with reference to FIG.2 and FIG.3, the bag making machine 1 which manufactures this bag 10 is demonstrated. The bag making machine 1 (here, a flat bag three-way bag making machine) includes a supply means 2, a bottom seal means 3, a side seal means 4, and a cutting means 5, which are arranged in order from the upstream side to the downstream side. ing. Hereafter, the bag making process in these means is demonstrated easily.

  In the supply means 2, the plastic film 91 on which the front printing 18 and the back printing 19 shown in FIG. 1 (iii) are applied is fed from the original fabric by the original fabric supply roll 22. The fed film 91 is changed in the direction of flow by the turn bar 21 provided to be inclined substantially at an angle of 45 °, and then half cut along the center line by the center cutting leather blade 23. The upper film 921 and the lower film 922 that have been half cut run in parallel with their flow directions being changed by the M plate 24, and further, a constant tension is applied by the raw roll feeding dancer roll 25.

  Further, in the supply means 2, the upper film 921 and the lower film 922 that run side by side are overlapped by a pair of ear-matching rolls 26 that face each other in the vertical direction. By tilting the rotation axis of the ear-matching roll 26, the meandering of one or both of the upper film 921 and the lower film 922 can be corrected to correct the edge shift.

Then, the upper and lower films 921 and 922 overlapped as shown in FIG. 1 (iv) are continuously sent out from the supply means 2 by the pair of raw fabric portion feed rolls 27.
In addition, the dashed-two dotted line in FIG.1 (iii) and FIG.1 (iv) shows an estimated cutting line.

  The sent upper and lower films 921 and 921 are heat-sealed by the bottom sealing means 3 and the side sealing means 4, and the chamfered portion 16 and the notch 17 are punched out by the cutting means 5, and cut into a bag shape, whereby the bag 10 is manufactured. The

<Displacement detection device>
Next, the deviation detection device will be described with reference to FIG.
FIG. 4 is a perspective view showing the deviation detecting device 6 arranged in the bag making machine. In FIG. 4, the illustration of the raw fabric portion feed roll 27 shown in FIGS. 2 and 3 is omitted. FIG. 5 is a cross-sectional view of the upper and lower films viewed from the upstream side of the bag making machine 1 and a side view of the deviation detecting device 6.

  As shown in FIG. 4, the shift detection device 6 includes a first imaging unit 611, a second imaging unit 612, a first bar illumination unit 621, a second bar illumination unit 622, a first ring illumination unit 631, and a second ring illumination. Means 632, a power supply unit 64, an image input unit 65, a control unit 66, a storage unit 67, and a display unit 68 are provided. Hereinafter, these components will be described in order.

  The first image pickup means 611 and the second image pickup means 612 are constituted by a CCD (Charge Coupled Device) camera, and as shown in FIGS. 2 and 3, the supply means 2 and the bottom seal means of the bag making machine 1. 3 is arranged.

As shown in FIGS. 4 and 5, the first imaging unit 611 and the second imaging unit 612 are substantially opposed in the vertical direction across the edges of the upper film 921 and the lower film 922 in an overlapped state. Are arranged.
In FIG. 4, the first image pickup means 611 and the second image pickup means 612 are arranged so as to be shifted from each other in the transport direction of the upper and lower films, but these image pickup means are arranged so that their optical axes coincide with each other. Also good.

  The first imaging means 611 captures the edges of the superimposed upper and lower films 921 and 922 from above (the surface side of the upper film 921), and generates a first image when the edges of the upper and lower films 921 and 922 are viewed from above. To do. The second imaging unit 612 captures the edges of the superposed upper and lower films 921 and 922 from below (the surface side of the lower film 922), and the second imaging unit 612 is a second view of the edges of the upper and lower films 921 and 922 viewed from below. Generate an image. Imaging by the first and second imaging means 611 and 612 is performed while intermittent (intermittent) conveyance of the upper and lower films 921 and 922 by the original fabric part feed roll 27 is intermittently stopped. The data of the first and second images is sent to the control unit 66 via the image input unit 65, stored in the storage unit 67, and displayed on the display unit 68 such as a liquid crystal display.

(Bar lighting means)
The first bar illumination means 621 and the second bar illumination means 622 are mainly used to illuminate transparent or translucent upper and lower films 921 and 922 formed of a transparent material such as polypropylene or polyester.

  Similarly to the first and second imaging means 611 and 612, the first and second bar illumination means 621 and 622 are also provided on the downstream side of the supply means 2 and the upstream side of the bottom seal means 3.

The first and second bar illumination means 621 and 622 have a rectangular light emitting surface in which LEDs are arranged in a matrix (row shape). As shown in FIG. 5, the first bar illumination means 621 is arranged on the sides of the edge portions 951 and 952 of the upper and lower films 921 and 922 with the light emitting surface facing these edge portions. As a result, the edges 951 and 952 of the upper and lower films 921 and 922 are illuminated from the side (that is, from the horizontal direction parallel to the surfaces of these films), and the surface of the upper film 921 is viewed obliquely from above in the width direction. Illuminated. The second bar illumination means 622 is also arranged on the sides of the edges 951 and 952 of the upper and lower films 921 and 922 so as to face these edges. As a result, the edges 951 and 952 of the upper and lower films 921 and 922 are illuminated from the side (that is, from the horizontal direction parallel to the surfaces of these films), and the surface of the lower film 922 is viewed from obliquely below the width direction. Illuminated.
Thus, the film edge can be effectively illuminated by illuminating from the side of the edge of the film and obliquely up and down. And the edge of the film imaged in the effectively shining state becomes a brighter (whiter) and more prominent linear image in the first and second images.
The first and second bar illumination means 621 and 622 may be integrally configured.

  The wavelength of the light emitted from the first and second bar illumination means 621 and 622 is within the light receiving sensitivity range of the first and second imaging means 611 and 612, for example, in the visible wavelength range (380 nm to 750 nm). Although it is preferable that the wavelength is within the range, a shorter wavelength is more preferable. Specifically, the peak wavelength is desirably in the range of 400 nm to 500 nm, more preferably in the range of 435 nm to 480 nm. The edge image of the film in the image picked up by emitting the blue light from the bar illumination means becomes clearer than that when the red light is irradiated. The reason why the sharpness of the edge of the film differs depending on the wavelength of the illumination light is thought to be because the intensity of the scattered light when illuminated with blue light is stronger than that for red light.

(Ring illumination means)
The first ring illumination means 631 and the second ring illumination means 632 are opaque upper and lower surfaces formed using a light shielding material such as an aluminum deposited film, a film with an aluminum foil layer, or a film with a light shielding ink layer. Mainly used to illuminate films 921 and 922. The first and second ring illumination means 631 and 632 have ring-shaped light emitting surfaces in which LEDs are arranged concentrically, and these light emitting surfaces are arranged around the first and second imaging means 611 and 612. It is arranged coaxially with the optical axis of the imaging means. Further, the power source unit 64 can provide each lighting unit with a light control function.

(Control part)
The control unit 66 functions as a deviation detection unit, identifies the edge image of the upper and lower films in the first and second images, and includes two (two) images in at least one of the first and second images. ) Is determined whether or not the edge image exists. The method for specifying the edge image in the image is not particularly limited, but a pixel group having brightness (white density) equal to or higher than a predetermined threshold may be specified as the edge image by image processing or the like, or the brightness and darkness in the image may be specified. A pixel group in which (the density of white, gray, and black colors) changes abruptly may be specified as an edge image. And if there are two specified edge images, a relative shift has occurred at the edges of the upper and lower films. When there is only one (one) edge image in both the first and second images, there is no relative shift. Further, the control unit 66 is relatively outside of the upper and lower films ( In FIG. 5, the film which is shifted to the left side) is specified.

  In the case where the edge of the opaque upper and lower film is displaced, two edge images are present only in the image taken by one of the first and second imaging means, and the other imaging means. There is only one edge image in the image captured by. This is because the edge of one film cannot be seen through the other opaque film.

In the case of an opaque film, this phenomenon can be used to determine which of the upper and lower films is relatively displaced outward. For example, when the opaque lower film 922 on the back side of the first image pickup means 611 is shifted outward from the opaque upper film 921 on the near side, the first image picked up from the upper side by the first image pickup means 611 is used. Two edge images exist only in one image, and only one edge image exists in the second image captured from the lower side by the second imaging unit 612.
Therefore, in the case of an opaque film, it is easily determined that the film on the back side is shifted outward from the film on the near side when viewed from the imaging means that has captured the image having two edge images. When the edge image is present in the captured image of the first imaging means 611, the lower film is displaced outward, and when it is present in the captured image of the second imaging means 612, the upper film is displaced outward. In addition, two edge images are displayed on one of the first and second images, but only one edge image is displayed on the other image, or the other image The same determination can be made even when it is difficult to extract the inner edge image in the image.

  By the way, when the film stacked up and down is transparent or translucent, both the first film imaged from the upper side and the second image imaged from the lower side of the upper film edge 951 and the lower film edge 952 Both are displayed. For this reason, it may be difficult to determine which edge of the upper and lower films is shifted outward only by the presence or absence of two edge images in the image.

  Below, the example which detects the shift | offset | difference of the edge part of a transparent or semi-transparent upper and lower film is demonstrated. For imaging opaque or translucent upper and lower films, first and second bar illumination means 621 and 622 are used.

  Here, (i) when the edges of the upper and lower films shown in FIG. 5 are aligned, (ii) when the lower film 922 shown in FIG. 8 is displaced outward (left side) from the upper film 921, And (iii) A case where the upper film 921 shown in FIG. 11 is displaced outward (left side) from the lower film 922 will be described.

(I) When the edges of the upper and lower films are aligned FIG. 6 shows a first image generated by imaging the upper and lower films shown in FIG. 5 from the upper side by the first imaging means 611 (the upper side of FIG. The downstream side and the lower side of the bag making machine 1 are the upstream side). 7 shows a second image generated by imaging the upper and lower films shown in FIG. 5 from the lower side by the second imaging means 612 (the upper side of FIG. 7 is the upstream side of the bag making machine 1, the lower side is the upper side). Downstream)).

  In the first image shown in FIG. 6, an upper film image 921 captured from the upper side and an edge portion 951 thereof are displayed. Even if it is a transparent film, a part of the irradiation light is reflected on the surface, so the brightness (white density) of the area of the upper film image 921 is the background area on the outside of the film (left side of the figure) without the reflector. Is brighter (white density is higher). Further, since the irradiation light from the side by the first bar illumination means 621 is scattered at the edge portion 951 (especially the side surface 931) of the film, the edge image 951 is brighter than the upper film image 921 area.

  On the other hand, in the second image shown in FIG. 7, a lower film image 922 and its edge image 952 captured from the lower side are displayed. The brightness (white density) of the area of the lower film image 922 is also brighter (higher) than the brightness (white density) of the background area outside the non-reflecting film (left side of the figure). Also, since the irradiation light from the side by the first bar illumination means 621 is scattered at the edge portion 952 (especially the side surface 932) of the film, the density of the edge image 952 is further brighter than the area of the lower film image 922. Yes.

  Since the positions of the edge images 951 and 952 of the upper and lower films 921 and 922 overlap each other, only one edge image is displayed in both the first and second images. In this case, the control unit 66 determines that there are no two edge images that are separated from each other in the first and second images (there is one edge image).

(Ii) When the lower film is displaced outward from the upper film FIG. 8 shows that the edge 952 of the lower film 922 is located outside the edge 951 of the upper film 921 as viewed from the upstream side of the bag making machine 1. It is sectional drawing of the upper and lower films 921 and 922 which have shifted | deviated, and the side view of the shift | offset | difference detection apparatus 6. FIG. 9 shows a first image generated by imaging the upper and lower films 921 and 922 shown in FIG. 8 from the upper side by the first imaging means 611 (the upper side in FIG. 9 is the downstream side of the bag making machine 1, and the lower side is the lower side. Upstream). 10 shows a second image generated by imaging the upper and lower films 921 and 922 shown in FIG. 8 from the lower side by the second imaging means 612 (the upper side of FIG. 10 is the upstream side of the bag making machine 1, The lower side is the downstream side).

  In the first image shown in FIG. 9, in addition to the upper film image 921 and its edge portion 951 taken from the upper side, the lower film image 922 and its edge portion protruding to the outside in the width direction of the upper film (left side in the figure). An image 952 is also displayed. On the other hand, in the second image shown in FIG. 10, not only the lower film image 922 and its edge 952 imaged from the lower side, but also an edge image 951 of the upper film 911 that can be seen through the lower film 922 is displayed. Yes. Therefore, the control unit 66 determines that there are two edge images in the first and second images. Since there are two edge images, a relative shift occurs at the edges of the upper and lower films.

  9 and 10, the right side of the first and second images is the inside of the upper and lower film images, that is, the center side. Therefore, in the first and second images under the situation of FIG. 8, of the two edge images 951 and 952, the edge image 951 located on the upper and lower film center side than the edge image 952 is the inner edge. An image is taken on the right side of the edge image 952.

  At this time, when the brightness (white density) of the inner edge image 951 appearing in the first image is compared with the brightness (white density) of the inner edge image 951 appearing in the second image, the first image What appears in the image is brighter (white density is higher) than that shown in the second image. This is because the inner edge image 951 in the first image is directly visible from the upper first imaging means 911, whereas the inner edge image 951 in the second image is the lower second imaging image. This is because it can be seen from the means 912 through the upper film 921.

  Therefore, the control unit 66 selects an image in which the brighter (high white density) inner edge portion 951 is imaged from the first and second images, and when the first image is selected, as shown in FIG. In addition, it is determined that the edge portion 952 of the lower film 922 on the back side (the lower side in FIG. 8) as viewed from the first imaging unit 611 is shifted outward from the edge portion 951 of the upper film 921.

(Iii) When the upper film is displaced outward from the lower film FIG. 11 shows that the edge 951 of the upper film 921 is located outside the edge 952 of the lower film 922 as viewed from the upstream side of the bag making machine 1. It is sectional drawing of the upper and lower films 921 and 922 which have shifted | deviated, and the side view of the shift | offset | difference detection apparatus 6. FIG. 12 shows a first image generated by imaging the upper and lower films 921 and 922 shown in FIG. 11 from the upper side by the first imaging means 611 (the upper side of FIG. 12 is the downstream side of the bag making machine 1, and the lower side is the lower side). Upstream). 13 shows a second image generated by imaging the upper and lower films 921 and 922 shown in FIG. 11 from the lower side by the second imaging means 612 (the upper side of FIG. 13 is the upstream side of the bag making machine 1, The lower side is the downstream side).

(Ii) As in the case where the lower film is displaced outward from the upper film, in the case of (iii), from the first and second images in FIG. 12 and FIG. It is determined that the images 951 and 952 exist (relative displacement occurs at the edges of the upper and lower films). Then, the control unit 66 selects the second image as the image in which the bright (high white density) inner edge is captured from the first and second images, and the second imaging unit 612 as illustrated in FIG. It is determined that the edge portion 951 of the upper film 921 on the back side (upper side in FIG. 11) as viewed from the side is displaced outward from the edge portion 952 of the lower film 922.
Thus, by specifying the positional relationship (how to shift) of the film shift, it is possible to correct the film shift.

(Displacement correction)
Next, deviation correction will be described.
The bag making machine 1 in this embodiment includes a deviation detection device 6 and further a deviation correction means. In addition to the control unit 66, the deviation amount correcting unit includes an inclination control unit 69 and a rotation unit 261.

  The controller 66 calculates the actual shift amount of the edges of the upper and lower films 921 and 922 based on the measured value of the interval between the edge images on the image. When calculating the actual edge shift amount, the ratio between the edge image interval value in the image and the actual edge width shift amount is obtained in advance and stored in the storage unit 67. The amount of deviation may be calculated by multiplying the ratio by the measured interval.

  The relative shift of the edges of the upper and lower films 921 and 922 is corrected by tilting the rotation axis of the ear-matching roll 26 shown in FIG. As shown in FIG. 14, which is a cross-sectional view taken along the line AA in FIG. 3, the ear-matching roll 26 is a pair of rollers that face each other in the upward and downward direction with a gap. The position of the upper film 921 is corrected by tilting the rotation axis of the upper ear-matching roll 26 from the horizontal state, and the position of the lower film 922 is corrected by tilting the rotation axis of the lower ear-matching roll 26 from the horizontal state. By doing so, it is possible to correct the relative displacement of the edges of the upper and lower films.

With reference to FIGS. 14 and 15, an example of correcting the deviation of the edge of the film will be described.
FIG. 15 is a plan view of the upper and lower films. The upper film 921 shown in FIG. 15 meanders or skews, and the edge of the upper film 921 is shifted in the + Y direction (rightward with respect to the flow direction when the upper film 921 is viewed in plan). In order to correct this deviation, the inclination control unit 69 controls the rotation means 261 such as a stepping motor to rotate so that the −Y direction side of the ear matching roll 26 shown in FIG. 14 is lowered by a predetermined rotation amount. Tilt the axis. As a result, the frictional resistance of the upper film 921 on the −Y direction side and the ear roll 26 is greater than the frictional resistance on the + Y direction side, and the upper film 921 moves to the −Y direction side. As a result, the meandering of the upper film 921 in the + Y direction is corrected to the −Y direction side, and the relative displacement between the edges of the upper and lower films is corrected.

  The rotation amount of the rotation shaft of the ear-matching roll 26 that is optimal for correcting the calculated edge shift is stored in advance in the storage unit 67 as a correspondence table or a relational expression in which the shift amount and the rotation amount are associated with each other. Yes. The tilt control unit 69 reads or calculates the optimum rotation amount of the rotation shaft of the ear-matching roll 26 from the storage unit 67 based on the deviation amount calculated by the control unit 66, and controls the rotation unit 261 to control the ear. The rotating shaft of the aligning roll 26 is inclined by the optimum amount of rotation. As a result, the relative deviation of the edges of the upper and lower films is corrected by correcting the meandering of the film. Thereby, it is possible to automatically correct the deviation with high accuracy.

<Shift detection method and shift correction method>
Next, a deviation detection method and a deviation correction method according to an embodiment of the present invention will be described with reference to the flowcharts of FIGS.

  As shown in the flowchart of FIG. 16, first, the first bar illumination means 621 of the deviation detecting device 6 irradiates the side surfaces 931 and 932 of the upper and lower films 921 and 922 and the surface 941 of the upper film 921 (S10). Subsequently, the first imaging unit 611 captures the upper film 921 and the lower film 922 illuminated by the first bar illumination unit 621 from the upper side to generate a first image (S11).

  Next, the second bar illumination means 622 irradiates the side surfaces 931 and 932 of the upper and lower films 921 and 922 and the surface 942 of the lower film 922 (S12). Subsequently, the second imaging unit 612 images the upper films 921 and 922 illuminated by the second bar illumination unit 622 from the lower side to generate a second image (S13).

  Subsequently, a deviation detection process (S14) and a deviation correction process (S15) described below are executed.

The deviation detection process (S14) will be described with reference to the flowchart of FIG.
The control unit 66 acquires the first image data from the first imaging unit 611 via the image input unit 65 (S20), and acquires the second image data from the second imaging unit 612 via the image input unit 65. (S21).

Next, the control unit 66 specifies the position of the edge image of the upper and lower films in the first image (S22), and further specifies the position of the edge image of the upper and lower film in the second image (S23).
Note that at this stage, it is not specified which of the upper and lower films each edge image in the image is.

  Next, the control unit 66 determines whether or not the positions of the edge images of the upper and lower films in the image are different from each other, that is, whether there are two edge images separated from each other in the first and second images. (S24).

  When only one edge image exists in the image as in the first image shown in FIG. 6 and the second image shown in FIG. 7, the control unit 66 causes a relative shift to the edges of the upper and lower films. It is determined that no occurrence has occurred (S25), and the deviation detection process is terminated.

  On the other hand, when there are two separated edge images in the image, such as the first image shown in FIG. 9 or FIG. 12 and the second image shown in FIG. 10 and FIG. An inner edge image is specified in each of the first and second images (S26). For example, in the first image shown in FIG. 9 and the second image shown in FIG. 10, the right edge image 951 is specified as the inner edge image among the two edge images 951 and 952 in the image. In the first image shown in FIG. 12 and the second image shown in FIG. 13, the right edge image 952 is specified as the inner edge image among the two edge images 951 and 952 in the image.

  Next, the control unit 66 specifies the brightness of the inner edge of the first and second images, and the brightness of the inner edge (white density) of the first image and the brightness of the inner edge of the second image. (White density) is compared (S27). Then, it is determined whether the inner edge in the first image is brighter than the inner edge in the second image (whether the white density is high) (S28). For example, when comparing the inner edge image 951 in the first image shown in FIG. 9 with the inner edge image 951 in the second image shown in FIG. It is determined that the partial image 951 is brighter (white density is higher and close to white). Then, the control unit 66 is configured such that the edge of the film on the back side is shifted outward from the edge of the film on the near side as viewed from the first image pickup unit 611 that picked up the first image. It is determined that the edge 952 is displaced outward from the edge 951 of the upper film 921 (S29).

  On the other hand, when the brightness of the inner edge image 952 in the first image shown in FIG. 12 is compared with the brightness of the inner edge image 952 in the second image shown in FIG. The inner edge image 952 in the inside is judged to be brighter, and the edge 951 of the upper film 921 on the back side is outside the edge 952 of the lower film 922 when viewed from the second imaging unit 612 that captured the second image. (S30).

  Subsequently, the control unit 66 measures the interval between the two edge images in the image, and calculates the shift amount between the edge portions of the two films based on the measured interval (S31). Further, the control unit 66 sends the calculated shift amount and information on which of the upper and lower films are shifted outward to the tilt control unit 69 (S32).

The deviation correction process (S15) will be described with reference to the flowchart of FIG.
When the tilt control unit 69 receives information about the shift amount and the upper or lower film from the control unit 66, the tilt control unit 69 receives the information about the shift amount and the information about the film on the outer side. The amount of rotation (one or each of the upper and lower sides) and the direction of rotation (+/−) are determined (S40), and the ear-matching roll 26 is inclined by the determined amount of rotation (S41). Thereby, the shift | offset | difference of the edge part of the upper and lower films 921 and 922 is corrected (S42).

As described above, according to the deviation detection device and method of the present embodiment, relative to the edge of the upper and lower films based on the first and second images generated by imaging the edges of the superimposed upper and lower films. Can be detected directly. In addition, based on the first and second images generated by imaging a transparent or translucent upper and lower film from the upper and lower directions, it can be specified which of the upper and lower fills is shifted outward. Furthermore, the deviation | shift amount of the edge part of an up-and-down film is computable based on one or both of a 1st and 2nd drawing. Then, based on the information on the relative shift amount of the upper and lower film edges and the information on which of the upper and lower film is shifted outward, the relative shift of the upper and lower film edges is appropriately corrected to thereby correct the lip shift. It can contribute to suppression of the above.
If the shift detection device is provided in the bag making machine as in this embodiment, it is possible to improve the reliability of the bag making machine, improve the quality of the produced bag-like container, and improve the bag yield.
When opaque upper and lower films 921 and 922 are used, the following points are changed.
In the illumination (S10) by the first bar illumination means 621 in the flowchart of FIG. 16, the opaque upper film 921 is illuminated by the first ring illumination means 631. In the illumination (S12) by the second bar illumination means 622, the opaque lower film 921 is illuminated by the second ring illumination means 632. In steps S10 and S12 at this time, illumination by the first bar illumination means 621 and the second bar illumination means may be omitted as appropriate.
In the flowchart of FIG. 17, when it is determined whether there are two edge images separated from each other in the first and second images (S <b> 24), they are separated from only one of the first and second images. It is determined whether there are two edge images. If neither of the first and second images has two edges (No), it is determined that no relative displacement has occurred at the edges of the upper and lower films (S25), and the displacement detection process is terminated. To do. When two edges exist only in one of the first and second images (Yes), the specification of the inner edge and its brightness (S26, 27) is omitted, and the inner edge of the first image is omitted. Instead of determining whether the portion is brighter (S28), it is determined whether two edge images exist in the first image. If it exists (Yes), it is determined that the lower film 922 is displaced outward (S29), and if it is not present (No), it is determined that the upper film 921 is displaced outward (S30). Note that if there are two edges in both the first and second images in decision S24, it is possible that there is a problem with the imaging means or that the transparent film is misused. It is preferable to perform error processing such as stopping.
As mentioned above, although the point different from a transparent or translucent upper and lower film at the time of using an opaque upper and lower film was demonstrated, other than that is the same as that of a transparent or translucent upper and lower film.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
The substantial configuration of the deviation detection device of the second embodiment is the same as that of the first embodiment shown in FIG. 4, but in the second embodiment, the deviation detection device is displaced to the outside of the upper and lower films. The processing method for identifying the film that is present, that is, the determination processing of the deviation detection method is different.

  In the second embodiment, when one of the first and second images includes two spaced-apart edge images, the control unit 66 serving as the detection unit converts the image into the two images. Dividing into three areas with the border image as the boundary, the brightness of each of the three areas is specified, and the difference between the brightness of the brightest area and the brightness of the next brightest area is predetermined. When the value is equal to or greater than the threshold value, it is determined that the edge of the film on the back side is shifted outward from the edge of the film on the near side when viewed from the imaging means that picked up the image. On the other hand, when the difference in brightness is less than the predetermined threshold value, it is determined that the edge of the film on the near side as viewed from the imaging means that captured the image is shifted outward from the edge of the film on the back side. .

Hereinafter, the deviation detection method will be described with reference to the flowchart of FIG. 21 taking the first image shown in FIGS. 19 and 20 as an example.
Also in the second embodiment, the control unit 66 is the same as the first embodiment until the step (S24) of determining whether or not two edge images exist in the image.

  19 is a first image generated by imaging the upper and lower films 921 and 922 shown in FIG. 8 from the upper side by the first imaging means 611. The upper side of FIG. 19 is the downstream side of the bag making machine 1, and the lower side is the upstream side. 20 is a first image generated by imaging the upper and lower films 921 and 922 shown in FIG. 11 from the upper side by the first imaging means 611, and the upper side of FIG. 20 is the downstream side of the bag making machine 1, The lower side is the upstream side.

  19 and 20, when the image includes two edge images, that is, the position of the edge 951 of the upper film 921 and the position of the edge 952 of the lower film 922. It is in a different position (S50). In this case, the control unit 66 divides the first image of FIGS. 19 and 20 into three areas of the first to third areas with the two edges 951 and 952 as boundaries (S51).

  Next, the control unit 66 specifies the brightness (white density) for each area (S52). In the first image shown in FIGS. 19 and 20, ranges D1 to D3 having the same area are set in the first to third areas, and the brightness (white density) in each range D1 to D3 is measured. The ranges D1 to D3 are set so as not to include the edge image.

  Next, the control unit 66 determines that the darkest (low white density) area among the three areas is the area where the background is projected (S53). In the first image shown in FIGS. 19 and 20, the first area is determined to be the background.

Next, the controller 66 determines the difference in brightness (white density) between the remaining second area and the third area, that is, the brightness (white density) of the brightest area and the next brightest area among the three areas. The difference is calculated (S54). Furthermore, the control unit 66 determines whether or not the difference in brightness (white density) is equal to or greater than a predetermined value (S55).
The predetermined threshold value used for determining the difference in brightness (white density) may be set by experimentally obtaining a suitable value.

  As a result of the determination, if the difference in brightness (white density) between the second area and the third area is large as shown in FIG. 19 and is equal to or greater than a predetermined threshold, the control unit 66 is as shown in FIG. 8 corresponding to FIG. Then, it is determined that the edge portion 952 of the lower film 922 on the back side is displaced outward from the edge portion 951 of the upper film 921 when viewed from the first image pickup means 611 that picked up the first image (S56).

  The difference in brightness (white density) between the second area and the third area becomes large as shown in FIG. 19 for the following reason. As shown in FIG. 8, the vicinity of the edge 951 of the upper film 921 is curled (curved) downward, and the upper surface thereof is inclined from the horizontal to the first bar illumination means 621 side. The upper surface near 951 is illuminated brightly from the side and obliquely upward by the first bar illumination means 621. On the other hand, the vicinity of the edge 952 of the lower film 922 is curled upward, and the upper surface is inclined from the horizontal to the side opposite to the first bar illumination means 621. The upper surface is illuminated relatively dark by the first bar illumination means 621. For this reason, the third area in FIG. 19 where the vicinity of the edge 951 of the upper film 921 is displayed is bright (the white density becomes higher), whereas the vicinity of the edge 952 of the lower film 922 is displayed. The second area in FIG. 19 is dark (white density is relatively low).

  As a result, as in the first image shown in FIG. 19, the difference between the brightness (white density) of the range D2 of the second area and the brightness (white density) of the range D3 of the third area is equal to or greater than a predetermined threshold. It becomes.

  Conversely, if the result of determination in step S55 is that the difference in brightness (white density) between the second area and the third area is less than a predetermined threshold as shown in FIG. 20, the controller 66 corresponds to FIG. As shown in FIG. 11, it is determined that the edge portion 951 of the upper film 921 on the near side as viewed from the first image pickup means 611 that has taken the first image is shifted outward from the edge portion 952 of the lower film 922 (S57). .

  The reason why the difference in brightness (white density) between the second area and the third area becomes small as shown in FIG. 20 is as follows. As shown in FIG. 11, when the upper film 921 is displaced outward from the lower film 922, the light emitted from the first bar illumination means 621 is emitted from both the second and third areas in FIG. In the area, the upper film 921 is reflected by the upper surface near the edge 951. Therefore, in the first image of FIG. 20 captured from above by the first imaging unit 611, the difference between the brightness (white density) of the second area D2 and the brightness (white density) of the third area D3 is small. Thus, the difference between the brightness (white density) of the second area range D2 and the brightness (white density) of the third area range D3 is less than a predetermined threshold.

  In this way, it is possible to identify a film that is relatively shifted to the outside of the upper and lower films 921 and 922. Subsequently, the control unit 66 measures the shift amount of the edge portions 951 and 952 of the upper and lower films 921 and 922 in order to correct the shift of the film edge portion (S58). Information on which of the two is displaced outward is sent to the inclination control unit 69 (S59). Hereinafter, the deviation is corrected as in the first embodiment.

[Third embodiment]
Next, a third embodiment according to the present invention will be described. In the present embodiment, the arrangement of the first and second imaging means 611 and 612 is different from that in the first embodiment.

FIG. 22 is a cross-sectional view of the upper and lower films of the present embodiment as viewed from the upstream side of the bag making machine 1 and a side view of the shift detection device.
As shown in FIG. 22, the first and second imaging means 611 and 612 are arranged with the optical axis inclined with respect to the normal line of the upper and lower films. Specifically, the optical axes of the first and second imaging means 611 and 612 passing through the edges 951 and 952 of the upper and lower films 921 and 922 are lateral to the normal line of the upper and lower film surfaces. First and second imaging means 611 and 612 are arranged so as to incline to the opposite side of the arranged first bar illumination means 621 and second bar illumination 622, respectively.

  Irradiation light from the first bar illuminating means 621 arranged on the lateral sides of the upper and lower films has an incident angle of 45 ° to 90 ° with respect to the normal line of the surface 941 of the upper film 921, and the upper film 921 Incident on the surface 941 from an oblique direction. Since the vicinity of the edge 951 of the upper film 921 is curled downward (curved), the incident angle with respect to the normal line of the surface 941 near the edge 951 is actually about 30 ° to 90 °. Similarly, the irradiation light from the second bar illumination means 622 is incident on the lower film from an oblique direction. As a result, the incident light is mainly reflected on the upper and lower film surfaces in an obliquely inner side in the width direction of the upper and lower films so that the reflection angle is substantially equal to the incident angle with respect to the film normal. Therefore, as shown in FIG. 22, if the first and second imaging means 611 and 612 are arranged with their optical axes inclined, the reflected light from the upper and lower films 921 and 922 can be effectively received. As a result, the upper and lower films 921 and 922 can be imaged more clearly.

Although the present invention has been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made.
For example, in the first embodiment, it is determined that the film on the back side of the imaging unit that has imaged the bright inner edge is shifted outward, but it is determined that the film on the front side of the imaging unit is shifted inward. May be. Further, it may be determined that the film on the near side of the imaging means in which the dark inner edge is imaged is shifted outward. (That is, the light / dark relationship of a predetermined image such as an edge and the positional relationship of film shift may be appropriately set as long as they are correct.)
In the second embodiment, the brightness difference between the second area and the third area is compared with a threshold value. However, the brightness of the second area may be directly compared with another predetermined threshold value.
In addition, when the deviation between the two films can be corrected in accordance with the measured value of the edge image interval, it is not necessary to calculate the deviation amount (actual dimension). Further, the deviation correcting means is not limited to this embodiment, and a known deviation correcting means may be used.
The first and second bar illumination means are not limited to LEDs, and may be straight tube fluorescent lamps or ordinary light bulbs (other than LEDs) arranged in a matrix, and in that case, blue fluorescent light It is more preferable to use a light or a light bulb.
Further, the first and second ring illumination means are not limited to LEDs, but round (circular) fluorescent lamps and normal (non-LED) light bulbs arranged concentrically around the first and second imaging means. Further, it may be arranged coaxially with the optical axis of the imaging means.

DESCRIPTION OF SYMBOLS 1 Bag making machine 2 Supply means 3 Bottom seal means 4 Side seal means 6 Deviation detection apparatus 10 Bag 26 Ear matching roll 66 Control part 69 Inclination control part 91 Film
261 Rotating means
611 First imaging means
612 Second imaging means
621 First bar lighting means
622 Second bar lighting means
631 First ring illumination means
632 Second ring illumination means
921 Upper film
922 Lower film
931 Top film side
932 Side of bottom film
941 Upper film surface
942 Lower film surface
951 Edge of upper film
952 Edge of lower film)

Claims (14)

A shift detection device that detects a shift between the edges of two superimposed films,
Illumination means for irradiating the two films with light;
A first imaging means for capturing an image of an edge of the two films from the surface side of one of the two films and generating a first image;
A second imaging means for imaging the edge from the surface side of the other of the two films to generate a second image;
Detecting means for detecting a relative shift between edges of the two films based on the first and second images;
The detection means includes
Identify edge images of the two films in the first and second images;
It is determined whether or not two edge images exist in at least one of the first and second images. The deviation detection apparatus according to claim 1, wherein a peak wavelength of light emitted from the illumination unit is 400 nm to 500 nm. The illuminating means illuminates an edge of the two films from a direction parallel to the surfaces of the two films, and illuminates one or both surfaces of the two films from an oblique direction. The deviation detection device according to claim 1, wherein the deviation detection device is disposed so as to be opposed to an edge portion of the two films. The first and second imaging means are configured such that the optical axis of each of the first and second imaging means passing through the vicinity of the edge of the two films is the edge of the film with respect to the normal of the two film surfaces. The deviation detecting device according to claim 3, wherein the deviation detecting device is arranged so as to be inclined to the opposite side to the illuminating means arranged facing the portion. When the detection means determines that the two edge images exist only in one of the first and second images, the back side as viewed from the image pickup means of the image determined that the two edge images exist It is characterized in that the film edge is determined to be shifted outside the edge of the film on the near side,
The deviation detecting device according to any one of claims 1 to 4. The detection means includes
When it is determined that the two edge images are present in each of the first and second images, depending on the brightness comparison result of the predetermined images in the first and second images, which of the two films is outside The shift detection device according to claim 1, wherein the shift detection device determines whether the shift has occurred. The predetermined image is
The inner edge image located on the center side of the two films than the other edge image of the two edge images,
Comparing the brightness of the inner edge image in the first image with the brightness of the inner edge image in the second image;
Select an image in which the brighter inner edge image appears among the first and second images,
The shift according to claim 6, wherein it is determined that the edge of the film on the back side as viewed from the imaging unit that picked up the selected image is shifted outward from the edge of the film on the near side. Detection device. The detection means includes
When it is determined that the two edge images exist in each of the first and second images,
The one of the two films is judged to be outside by judging the magnitude of the value indicating the brightness of the predetermined image in the first or second image with respect to a threshold value. The deviation detection device according to any one of the above. A value indicating the brightness of the predetermined image is
The one image is divided into three areas with the two edge images as a boundary, the brightness of each of the three areas is specified, and the brightness of the brightest area among the three areas is Is the difference between the brightness of the bright area and
When the value calculated as the difference is equal to or greater than the predetermined threshold value, the edge of the film on the back side as viewed from the imaging means that picked up the one image is shifted outward from the edge of the film on the near side. And
When the difference is less than a predetermined threshold value, it is determined that the edge of the film on the near side as viewed from the imaging means that has captured the one image is shifted outward from the edge of the film on the back side. The deviation detection device according to claim 8. When the detection means determines that the two edge images exist,
The distance between the two edge images in the one image is measured, and the amount of deviation between the edges of the two films is determined based on the measured distance. A deviation detecting device according to claim 1. In a misalignment correcting device that corrects misalignment between the edges of two films superimposed in a bag making machine,
The orthogonality to the flow direction of one or both of the two films based on the amount of deviation determined by the deviation detection device according to claim 10 and the positional relationship between the deviations of the two films. A deviation correcting device, further comprising correcting means for correcting the position in the width direction. The correcting means is
A rotation unit that inclines the rotation axis of the roll member that guides the two films in the bag making machine;
The deviation correction device according to claim 11, further comprising an inclination control unit that controls a rotation amount of the rotation shaft by the rotation unit based on the determined amount of deviation. A deviation detection method for detecting a relative deviation between edges of two superimposed films,
An illumination step of irradiating the two films with light;
A first imaging step of imaging the edge of the two films from the surface side of one of the two films to generate a first image;
A second imaging step of imaging the edge from the surface side of the other of the two films to generate a second image;
Detecting a shift of the edge of the two films based on the first and second images,
The detection step includes
Identifying edge images of the two films in the first and second images;
A step of determining whether or not two edge images exist in at least one of the first and second images. In the method of correcting the misalignment of the edges of two superimposed films in a bag making machine,
The film edge shift detected by the shift detection method according to claim 13 is corrected by correcting the position in the width direction perpendicular to the flow direction of one or both of the two films. A deviation correction method characterized by the above.