Labels and Inspection Methods

Abstract

To provide a label with a novel configuration allowing accurate detection of sticking failure, and a novel inspection method for sticking failure.SOLUTION: A rectangular label to be wound around and stuck on a container comprises a fiducial mark for pattern matching by image detection, and a pair of marks to be detected disposed at both ends in the winding direction and subjected to image detection at predetermined positions, respectively, relative to the fiducial mark.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a label that is wrapped around and affixed to a container such as a plastic bottle into which a beverage is filled, and more particularly to a technique for detecting improper application of the label. [Background technology]

[0002] Conventionally, there is known an inspection method for capturing an image of the appearance of a label attached to a container such as a plastic bottle filled with a liquid such as a beverage, and inspecting the same, as disclosed in, for example, Patent Document 1. Patent Document 1 particularly discloses a method for inspecting misalignment of the label.

[0003] Furthermore, Patent Document 2 discloses a method of imaging an attachment location of a label wrapped around the cylindrical surface of a cylindrical product to detect defects (wrinkles in the label). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 6-138057 [Patent Document 2] Patent No. 6769269 specification Summary of the Invention [Problem to be solved by the invention]

[0005] The labels that are wrapped around and affixed to the containers described above are known as roll labels, and there is a concern that the labels may be affixed at an angle, resulting in misalignment, or that the labels may develop wrinkles, resulting in poor application. Therefore, a more accurate inspection method is required.

[0006] In view of the above problems, the present invention proposes a label having a novel configuration that enables defective application to be detected with high accuracy, and a novel method of inspecting defective application. [Means for solving the problem]

[0007] The problem to be solved by the present invention has been described above, and the means for solving this problem will now be described.

[0008] In one form of the present invention, a rectangular label is wrapped around a container and affixed, the label comprising a reference mark for pattern matching by image detection, and a pair of detectable marks provided at both ends in the wrapping direction, each of which is image-detected at a predetermined position relative to the reference mark.

[0009] In one embodiment of the present invention, each of the detectable marks is in a strip shape that is long in the winding direction, and the length of one of the detectable marks is longer than the length of the other of the detectable marks.

[0010] In one embodiment of the present invention, the detection marks are provided at the same position in a width direction of the label that is perpendicular to the wrapping direction.

[0011] In one aspect of the present invention, the pair of detection marks are provided at a plurality of positions in the width direction of the label.

[0012] In one embodiment of the present invention, the reference mark is arranged to overlap one of a pair of detectable marks, and has a triangular shape located near a corner of a rectangular label.

[0013] In one aspect of the present invention, a transparent portion is provided around the detection mark.

[0014] In addition, one form of the present invention is an inspection method for detecting defective label attachment, characterized in having a first step of detecting the reference mark by pattern matching, a second step of detecting a detectable mark at each of two predetermined positions relative to the detected reference mark, and a third step of determining defective label attachment based on the detected detectable marks.

[0015] In one aspect of the present invention, a transparent portion is provided around the detection mark. Effect of the Invention

[0016] According to one aspect of the present invention, it is possible to realize a label having a novel configuration that enables detection of defective application with high accuracy, and a novel inspection method for defective application.

[0017] According to one embodiment of the present invention, by ensuring a certain length for long detectable marks, it is possible to provide a margin of error in detection accuracy and increase the degree of freedom in pass / fail judgment. On the other hand, for short detectable marks, it is sufficient to ensure the minimum length necessary for detection, and it is possible to prevent the detectable marks from damaging the label design.

[0018] Furthermore, according to one aspect of the present invention, the pair of detection marks is provided at multiple locations in the width direction of the label, making it possible to inspect for defective label attachment at multiple locations.

[0019] In addition, according to one embodiment of the present invention, by making the reference mark triangular, the reference mark can function as a label removal mark indicating the label removal point (the place where the label is to be picked up) when disposing of the container.

[0020] Furthermore, according to one embodiment of the present invention, in a label in which transparent areas are provided around a detectable mark, additional detectable marks can be provided without compromising the design based on transparency. [Brief description of the drawings]

[0021] [Figure 1] (A) is a diagram explaining the configuration of the container and the label, (B) is a diagram explaining the state in which the label is partially attached, and (C) is a diagram explaining the state in which the label is completely attached. [Diagram 2] FIG. 4 is a diagram for explaining an embodiment of a label. [Diagram 3] (A) is a diagram for explaining another embodiment of the label, (B) is a diagram for explaining another embodiment of the label, (C) is a diagram for explaining another embodiment of the label, and (D) is a diagram for explaining another embodiment of the label. [Figure 4] 1A is a diagram for explaining another embodiment of the label, and FIG. 1B is a diagram for explaining another embodiment of the label. [Diagram 5] FIG. 1 is a schematic diagram showing an example of the configuration of a label inspection device. [Figure 6] FIG. 11 is a diagram showing an example of a captured image. [Figure 7] FIG. 11 is a diagram showing another example of a captured image. [Figure 8] (A) is a diagram for explaining an example of a captured image when a label is properly attached, (B) is a diagram for explaining an example of a captured image when a label is improperly attached, (C) is a diagram for explaining another example of a captured image when a label is improperly attached, and (D) is a diagram for explaining another example of a captured image when a label is improperly attached. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. For ease of explanation, in the container 1 shown in Fig. 1(A) to (C), the upper side of the paper surface is the upper position, the lower side is the lower position, the up-down direction is the height direction, and the central axis 1C of the container 1 is the up-down direction. In addition, in the strip-shaped label 2 shown in Fig. 1(A) to (C), the up-down direction of the paper surface is the width direction Dy of the label 2, the length direction Dx of the label 2 in the left-right direction of the paper surface or the winding direction Dx, and the ends in the left-right direction are one end Ta and the other end Tb of the winding direction Dx.

[0023] 1(A) to 1(C), a rectangular strip-shaped label 2 is a roll label that is wrapped around and attached to the body 1a of a container 1. In a labeler (label attachment device) not shown, the continuous label wound on a roll is cut to a predetermined length, and one end Ta of the label 2 is attached to the body 1a of the container 1 with an adhesive or the like, and then the container 1 is rotated so that the label 2 is wrapped around the container 1 and the other end Tb of the label is attached so as to overlap the one end Ta. The overlapping portion of the other end Tb and the one end Ta constitutes the attachment portion Tc.

[0024] The container 1 is a container such as a plastic bottle, such as a so-called PET bottle (pet bottle), or a glass bottle, and is a round bottle with a cylindrical body or a bottle with a rectangular tubular body, and there are no particular limitations on the material or details of the shape. The contents filled in the container are not particularly limited, and may be soft drinks such as juice, water, and tea, as well as liquid seasonings, medicines, paints, etc.

[0025] 2, the label 2 is configured as a horizontally long rectangle, and the surface that appears when wrapped around a container is the outer surface 22. It is intended that the back side of one end Ta on the left side is attached to the container side, and the other end Tb on the right side is overlapped on the outside of one end Ta.

[0026] 2, a reference mark 24 for pattern matching by image detection appears on the outer surface 22 of the label 2. The reference mark 24 may be printed or the like on the inner surface (the surface opposite the outer surface 22) of the label 2 so as to be visible to the outside, or it may be printed or the like on the outer surface 22.

[0027] As shown in FIG. 2, detection marks 26 and 28 for image detection are provided at predetermined positions relative to the reference mark 24 on both ends of the label 2 in the wrapping direction Dx.

[0028] 2, each of the detectable marks 26, 28 is configured as a strip-shaped mark extending inward in the winding direction Dx from an end side of the label 2, and the length 26L of one of the detectable marks 26 is configured to be longer than the length 28L of the other of the detectable marks 28. For example, the length 26L of one of the detectable marks 26 is configured to be approximately 1.5 to 2 times longer than the length 28L of the other of the detectable marks 28. For example, it is possible to set the length 26L of the detectable mark 26 to 3 cm, and the length 28L of the detectable mark 28 to 1.5 cm.

[0029] 2, the detection marks 26, 28 are provided at the same position in the width direction Dy of the label that is perpendicular to the winding direction Dx. As a result, if there are no attachment defects such as misalignment or wrinkles in the label 2, the detection marks 26, 28 will appear at the same height when the label 2 is wound.

[0030] As shown in Fig. 2, the reference mark 24 may be provided on the detection mark 28, or may be provided at a position that does not overlap with the detection mark 28 (Fig. 3(A)). The position of the reference mark 24 is not particularly limited as long as the reference mark 24 is reliably recognized by pattern matching after the label 2 is affixed. Also, for example, if the label is wrapped in the opposite direction, the reference mark 24 and the detection marks 26, 28 in Fig. 2 may be arranged so that they are reversed left to right.

[0031] In this embodiment, the reference mark 24 is arranged to overlap one of the detection marks 28 and has a triangular shape provided near the corner 2a of the label 2. By making it triangular in shape, it can function as a peeling opening mark that indicates the peeling opening (the place where the label is picked up) of the label 2 when the container 1 is disposed of. Note that the reference mark 24 does not have to function as a peeling opening mark, and may be provided at a position different from the peeling opening mark. In addition to the triangular shape, the reference mark 24 may be a circle, a square, a barcode, or the like, and is not particularly limited as long as it has a shape that can be pattern matched by image detection.

[0032] Furthermore, as shown in FIG. 3(A), the pair of detection marks 26, 28 may be provided at a second location D2 located on the lower side in the width direction Dy of the label 2.

[0033] 3B, the pair of detection marks 26, 28 may be provided at two locations in the width direction Dy of the label 2. That is, the pair of detection marks 26, 28 may be provided at a first location D1 located on the upper side of the width direction Dy of the label 2, and the pair of detection marks 26, 28 may be provided at a second location D2 located on the lower side of the width direction Dy of the label 2. This makes it possible to inspect for defective label attachment at multiple locations, each of the first location D1 and the second location D2. Note that inspection is not limited to two locations, the first location D1 and the second location D2, and more locations may be inspected.

[0034] 3C, the reference mark 24 may be provided at the location of the detection mark 28 at the second location D2 on the lower side. Alternatively, the reference mark 24 may be provided at both the detection mark 28 at the first location D1 and the second location D2.

[0035] 3(D), a continuous band-like detectable mark 29 may be provided at the second location D2 on the lower side so as to extend in the winding direction Dx of the label 2. Alternatively, a continuous band-like detectable mark 29 may be provided at the first location D1 on the upper side, and a pair of detectable marks 26, 28 may be provided at the second location D2 on the lower side.

[0036] As shown in Fig. 2, the detectable marks 26, 28 may be surrounded by transparent areas. That is, the detectable marks 26, 28 are provided on a label with a transparent background for the detectable marks 26, 28. For example, in the case of attaching a label 2 to a transparent container, the present invention can be applied to a label design in which the area surrounding the design 2Z is ​​transparent 2T to allow the color of the beverage (e.g., the orange of orange juice) to appear on the outside by providing the detectable marks 26, 28. In this case, it is preferable that the color of the juice and the colors of the detectable marks 26, 28 are colors that can be distinguished by an image detection device.

[0037] Furthermore, by providing the detection marks 26, 28 in a strip shape of the minimum required length so as to be inconspicuous at the end of the label, the present invention can be implemented without compromising the overall design of the label 2. In particular, when the label 2 is based on a transparent design, the detection marks 26, 28 can be additionally provided without compromising the transparent design, which is a preferred embodiment.

[0038] As shown in FIG. 4(A), the detectable marks 26, 28 may be transparent and the periphery of the detectable marks 26, 28 may be opaque, or as shown in FIG. 4(B), the detectable marks 26, 28 may be a first color and the periphery of the detectable marks 26, 28 may be a second color different from the first color. As long as the detectable marks 26, 28 can be detected, the form is not particularly limited.

[0039] 5, defective application of the label 2 is inspected by an inspection device 30. The inspection device 30 includes a plurality of cameras 31 for capturing images of the label 2 affixed to the container 1 from all directions, and a controller 32 for controlling the cameras 31.

[0040] 5 is a schematic diagram of the inspection device 30 seen from above, and in this embodiment, the inspection device 30 is provided with four cameras 31, which are allocated and arranged in groups of two on each side of the conveyor line 40 along which the containers 1 are continuously conveyed. By providing multiple cameras 31, it is possible to image the entire area of ​​the label 2, and it is possible to image the reference mark 24 (FIG. 2) provided on the label 2 regardless of the orientation of the container 1 (the angle in the rotational direction around the central axis 1C of the container).

[0041] As shown in FIG. 5, each camera 31 is connected to a controller 32, and each camera 31 acquires a captured image 34 of the label 2 under the control of the controller 32.

[0042] 5 and 6, the controller 32 detects the reference mark 24 by pattern matching from among the obtained multiple captured images 34. More specifically, a key pattern 25 corresponding to the reference mark 24 is registered in advance in the controller 32, and the controller 32 recognizes the reference mark 24 that matches the key pattern 25 from among the captured images 34.

[0043] FIG. 6 is an example of the captured image 34. As shown in FIG. 6, the controller 32 identifies, for example, the position of the center of gravity of a right-angled triangular key pattern 25 as a reference point 24a, and defines the coordinate axes 5 based on the reference point 24a.

[0044] 6, inspection areas KL, KR are preset in the controller 32. The inspection areas KL, KR are set at predetermined coordinate positions on the coordinate axes 5 defined in the captured image 34. In this embodiment, the inspection areas KL, KR are set at positions spaced a predetermined distance from the reference mark 24 in the left-right direction (wrapping direction Dx) of the reference mark 24.

[0045] Fig. 7 shows an example of a captured image 34A of a label 2 in a different form. This captured image 34A is an image captured when capturing an image of the label 2 shown in Fig. 3(A). In this way, when the reference mark 24 is misaligned with the detection marks 26, 28 in the width direction Dy, the inspection regions KL, KR are set at positions at a predetermined distance from the reference mark 24 in the left-right direction (winding direction Dx) and the width direction Dy, respectively.

[0046] The controller 32 then determines whether or not there is a defective attachment based on the state of each of the detection marks 26, 28 appearing in each of the inspection areas KL, KR. Specifically, the edges (contours) of the detection marks 26, 28 appearing in the inspection regions KL, KR are recognized from differences in color tone, and a judgment is made using the coordinates in the width direction Dy and the coordinates in the wrapping direction Dx of the detection marks 26, 28. Note that, in order to make the edges of the detection marks 26, 28 easier to recognize, a color having a higher reflectance than other parts may be adopted for the detection marks 26, 28.

[0047] The presence or absence of a bonding defect is judged as follows. 8A, in each inspection region KL, KR, the lower edges E1, E2 of each of the marks to be detected 26, 28 are detected, and the coordinates (height direction positions) of the edges E1, E2 in the width direction Dy are compared, and if the difference in the coordinates in the width direction Dy is within a predetermined range, it is determined that there is no attachment defect in the width direction Dy. Note that instead of detecting the lower edges E1, E2 of each of the marks to be detected 26, 28, the upper edges of each of the marks to be detected 26, 28 may be detected.

[0048] On the other hand, for example, as shown in FIG. 8(B), if the coordinates of the width direction Dy of the lower edges E1, E2 of each detection mark 26, 28 are significantly shifted, it is presumed that the label has been attached diagonally or shifted up or down, and it is determined that there is a defective attachment.

[0049] Also, as shown in FIG. 8(A), for example, in one inspection area KL, the presence or absence of an edge E4 in the winding direction Dx of the detection mark 28 is detected, and if the edge E4 is present within the inspection area KL, it is determined that there is no attachment defect in the width direction Dy.

[0050] On the other hand, for example, as shown in FIG. 8(C), if the edge E3 of the detection mark 28 is not confirmed within the inspection area KL, it is determined that the label is wrinkled and the detection mark 28 is located farther away from the reference mark 24 than the specified position, and there is a defective attachment in the wrapping direction Dx.

[0051] In the example of FIG. 8D, since none of the edges of the detection mark 26 are detected within the inspection area KL, it is presumed that the label has a large wrinkle or curl, and it is determined that there is a defective attachment.

[0052] In this manner, improper label attachment can be detected. That is, a first step of detecting the reference mark 24 by pattern matching; a second step of detecting the detection marks 26 and 28 at two predetermined positions relative to the detected reference mark 24; and a third step of judging whether the label is attached improperly based on the detected detection marks 26, 28.

[0053] In this way, improper label attachment can be detected with high accuracy.

[0054] Here, as shown in Fig. 2, the length 26L of one of the detection marks 26 is configured to be longer than the length 28L of the other detection mark 28. This allows the detection mark 26 formed on one end Ta of the label 2 at the bonding point Tc to be exposed to the side of the other end Tb of the label 2 without being hidden by the other end Tb, and to be detected, as shown in Fig. 6. In other words, the detection mark 26 can be reliably exposed without being hidden by the other end Tb of the label 2.

[0055] Furthermore, by ensuring a certain length for the long detection mark 26, it is possible to provide a margin of error in detection accuracy and increase the degree of freedom in pass / fail judgment. On the other hand, for the short detection mark 28, it is sufficient to ensure the minimum length necessary for detection, and it is possible to prevent the detection mark 28 from spoiling the design of the label 2. [Explanation of symbols]

[0056] 1 container 1C center axis 1a Torso 2. Label 2a Corner 5. Coordinates 22 External surface 24 Reference Mark 24a Reference point 26 Detection mark 28 Detection mark 30 Inspection Equipment 31 Camera 32 Controller 34 Captured images D1 First Place D2 Second place Dx Winding direction Dy width direction KR Inspection area KL Inspection Area Ta one end Tb other end Tc Bonding point

Claims

1. A rectangular strip-shaped label that is wrapped around a container and affixed as a roll label, A reference mark for pattern matching in image detection by capturing an image of a label wrapped around a container; a pair of detection marks provided at both ends in a winding direction, the detection marks being adapted to be image-detected at predetermined positions relative to the reference mark in a captured image used for image detection of the reference mark; Equipped with A label, wherein the reference mark and the detectable mark are different marks having different shapes and / or colors.

2. Each of the detection marks is in the form of a strip that is long in the winding direction, The length of one of the marks to be detected is longer than the length of the other of the marks to be detected.

2. The label of claim 1.

3. The detection marks are provided at the same position in a width direction of the label perpendicular to the wrapping direction.

3. The label according to claim 1 or 2.

4. The pair of detection marks are provided at a plurality of positions in a width direction of the label. A label according to any one of claims 1 to 3.

5. the reference mark is disposed so as to overlap one of a pair of detection marks, and has a triangular shape provided near a corner of a rectangular label; 5. A label according to any one of claims 1 to 4.

6. A transparent area is provided around the detection mark. A label according to any one of claims 1 to 5.

Images