JP2008281477A - Label inspecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a label inspecting method capable of easily manufacturing transparent labels and hardly affected by printing colors. <P>SOLUTION: The method inspects damage of a transparent label 9 mounted on the outer periphery of a transparent resin vessel 11. The transparent label 9 is formed by printing on a transparent base film which irradiates fluorescence having intensity different from that of the transparent resin vessel 11. When ultraviolet ray is irradiated from an ultraviolet irradiating part 3 to the transparent label mounted on the transparent resin vessel, the contrast of the fluorescent image obtained by a camera is compared with the contrast of the transparent label 9 having no damage by a control part 7 to detect damage of the transparent label 9. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a label inspection method for detecting damage such as a loss, a sag, or a shift of a transparent label attached to a body of a transparent resin container containing a beverage.

  Generally, in beverage-containing transparent resin containers such as PET (polyethylene terephthalate) bottles, a label for product display is attached to the container body, but recently, this type of label is printed with ink on a transparent substrate film. Many transparent labels are used. When such a transparent label is attached, there is a problem that it becomes difficult to detect the damage of the label, for example, if the label is torn from the perforation, or is damaged such as a defect, a sag, or a shift.

  On the other hand, as a method for detecting label damage of a transparent resin container, Patent Document 1 provides a near infrared absorption layer on the surface of a transparent substrate film, and irradiates a container equipped with a label with near infrared light. In addition, it is disclosed that a label damage is detected by photographing an infrared image with a CCD camera.

JP 2003-302905 A

  However, the technique of Patent Document 1 has a problem that it takes time and effort to produce a near infrared absorption layer on the surface of the transparent substrate film.

  Moreover, in the method of irradiating a near infrared ray to the near infrared ray absorbing layer, the detection accuracy may be lowered due to the influence of the color printed on the transparent substrate film.

  Therefore, an object of the present invention is to provide a label inspection method that is easy to manufacture a transparent label and is not easily influenced by the color to be printed.

  In order to solve the above-mentioned problem, the invention described in claim 1 is a label inspection method for inspecting damage of a transparent label mounted on the outer periphery of a transparent resin container, and the transparent label is transparent resin by irradiation with ultraviolet rays. It is formed by printing on a transparent substrate film that emits fluorescence with a different intensity from the container made, and damages the light and darkness of the fluorescent image obtained by irradiating ultraviolet rays toward the transparent label attached to the transparent resin container. It is characterized by detecting the damage of the transparent label as compared with the light and darkness in the case where there is no light.

  The difference in the intensity of fluorescence emitted by irradiation with ultraviolet rays may be higher or lower than that of the transparent substrate film in the transparent resin container.

  As the transparent substrate film that emits fluorescence when irradiated with ultraviolet rays, a transparent resin film having such properties (acrylic resin film, amino resin film, styrene resin film, etc.) may be used. A resin film mixed with a fluorescent pigment (such as an acrylic resin pigment or an amino resin pigment) may be used.

  The invention described in claim 2 is characterized in that, in the invention described in claim 1, the transparent resin container is made of polyethylene terephthalate, and the transparent substrate film is a polystyrene film.

  The invention described in claim 3 is characterized in that, in the invention described in claim 2, the ultraviolet ray is light of a blue light emitting diode.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the fluorescent image is received by the CCD camera, and “0” and “1” are obtained based on the amount of light received by each pixel in the image sensor of the CCD camera. The damaged area of the label is displayed by expressing the binary image and comparing the fluorescent images numerically.

  The invention described in claim 5 is the invention described in claim 4, wherein the CCD camera is provided on the ultraviolet irradiation side and receives light emitted from the surface of the transparent label by the ultraviolet irradiation.

  The invention described in claim 6 is a label inspection method for inspecting damage to a transparent label mounted on the outer periphery of a transparent resin container, wherein the transparent label is formed by printing on a transparent substrate film. The film contains an ultraviolet absorber, and UV light is applied to the transparent label attached to the transparent resin container, and the UV image obtained by transmitting the light is dark and bright when the transparent label is not damaged. The comparison is characterized by detecting the damage of the transparent label.

  Examples of ultraviolet absorbers include benzotriazole, benzophenone, and triazine pigments.

  The invention described in claim 7 is characterized in that, in the invention described in claim 6, the ultraviolet light is light of a blue light emitting diode.

  According to an eighth aspect of the present invention, in the seventh aspect of the present invention, the ultraviolet image transmitted through the transparent resin container is received by the CCD camera, and the “light receiving amount of each pixel in the image sensor of the CCD camera” The damage area of the label is displayed by representing the binary value of “0” and “1” and comparing the ultraviolet image numerically.

  According to the first aspect of the present invention, since the transparent substrate film emits fluorescence having a different intensity from that of the transparent resin container upon irradiation with ultraviolet rays, the resin container and the transparent label are used in a place where the transparent label is not damaged. When the transparent label is damaged, the fluorescent light is received only from the resin container. Therefore, since the intensity of the fluorescence is different at the place where the transparent label is damaged, the damage of the transparent label can be detected from the brightness and darkness of the fluorescent image.

  It is not necessary to form a damage detection layer (for example, a near-infrared absorbing layer) on the surface of the transparent substrate film as in the prior art, and the label can be easily manufactured.

  Since it is compared with a fluorescent image when the transparent label is not damaged, it is difficult to be influenced by the printed color ink in the label inspection.

  According to invention of Claim 2, while having the effect of Claim 1, as a result of experiment, as shown in FIG. 4, PET bottle (polyethylene terephthalate bottle) has high strength by irradiation with ultraviolet rays. It was found that the OPS film (polystyrene film) emits fluorescence with lower intensity than PET bottles. Therefore, when a highly versatile OPS film substrate label is mounted on a highly versatile PET (polyethylene terephthalate) bottle, the difference in fluorescence from the PET bottle is large, and label damage is easy to detect.

  According to the third aspect of the invention, the blue light emitting diode has less heat generation and the light quantity is stable, and the maintenance is easy.

  According to the invention described in claim 4, the operational effect described in claim 3 is achieved, and the brightness and darkness of the fluorescent image is digitized in binary, so that the image processing is easy and the damaged part is easily understood.

  According to the fifth aspect of the present invention, the function and effect of the fourth aspect can be achieved and the detection can be performed without being affected by the contents of the container, so that the detection accuracy is high.

  According to the sixth aspect of the present invention, the ultraviolet rays transmitted through the transparent resin container are absorbed where there is a label, and are transmitted without being absorbed where there is no label. Therefore, the damage of the label can be detected by comparing the ultraviolet image transmitted through the transparent resin container with the ultraviolet image when the label is not damaged.

  Only the ultraviolet absorbing material is mixed into the transparent substrate film of the label, and it is not necessary to form a layer for detecting damage on the surface of the transparent substrate film as in the prior art, and the production of the label can be facilitated.

  Since it is compared with an ultraviolet image when the transparent label is not damaged, it is difficult to be influenced by the printed color ink in the label inspection.

  According to the seventh aspect of the invention, the blue light emitting diode has less heat generation and the light quantity is stable, and the maintenance is easy.

  According to the eighth aspect of the invention, the effects described in the seventh aspect are achieved, and the brightness and darkness of the fluorescent image is digitized in binary, so that the image processing is easy and the damaged portion is easily understood.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Hereinafter, the first embodiment will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram of a label inspection apparatus according to an embodiment of the present invention, FIG. 2 is a plan view showing an arrangement of a camera and an ultraviolet irradiation unit in label inspection, and FIG. 3 is a beverage with a label attached thereto. FIG. 4 is a side view showing the relationship between the ultraviolet irradiation of the container and the camera, FIG. 4 is a graph showing the relationship of the fluorescence intensity between the label and the beverage bottle (PET bottle), and FIG. 5 is an example of a damaged label. FIG. 6 is a plan view showing pixels in fluorescent image processing, FIG. 7 is a front view of a beverage container showing an example of a label shifted in position, and FIG. It is a top view of the pixel which carried out the fluorescence image process of the drink bottle shown in FIG.

  The label inspection apparatus 1 according to the embodiment of the present invention includes an ultraviolet irradiation unit 3, a camera 5, and a control unit 7 that processes an image signal from the camera 5.

  The ultraviolet irradiation unit 3 and the camera 5 are arranged at a label inspection position in the transport path 13 of the beverage bottle 11 to which the label 9 is attached. The beverage bottle 11 is a transparent resin container in which a beverage is stored. When the beverage bottle 11 is conveyed to the label inspection position on the conveyance path 13, a detection signal is issued to the control unit 7.

  In the present embodiment, the beverage bottle 11 is a PET bottle (polyethylene terephthalate bottle).

  As shown in FIGS. 3 and 5, the label 9 is attached to the body of the beverage bottle 11 and is manufactured by printing a product display or the like with ink on a transparent substrate film. In the present embodiment, a biaxially stretched polystyrene (OPS) film is used as the transparent substrate film, and the thickness is about 50 μm.

  The ultraviolet irradiation unit 3 is provided with a large number of blue light emitting diodes 15 and emits light toward the beverage bottle 11 to irradiate ultraviolet rays (main wavelength is 375 nm). This ultraviolet irradiation part 3 is arrange | positioned between the camera 5 and the drink bottle 11, and the hole 17 which permeate | transmits the light reflected in the center is formed. That is, the fluorescence generated by the irradiation of ultraviolet rays is received by the camera 5 from the hole 17.

  The camera 5 is a CCD (imaging device) camera. As shown in FIG. 2, a plurality of cameras (6 in the present embodiment) are provided so as to surround the beverage bottle 11. is there.

  Image signals captured by each camera 5 are transmitted to the control unit 7. The control unit 7 includes an image processing unit 19 that performs image processing from an image signal, a comparison unit 21, and a memory 23. The image processing unit 19 sets the received fluorescence intensity to “0” or “1”. It is converted into binary (in other words, “ON” and “OFF”), and on / off display is performed for each pixel as shown in FIG. For example, the hatched portion 29 in FIG. 6 is “1” having a high fluorescence intensity, and the remaining portion “0” is a portion having a low fluorescence intensity. Depending on the inspection accuracy, the image may be analyzed with the grayscale (black and white or color) before binary conversion.

  The memory 23 stores reference data obtained by converting a fluorescence image into a binary value when the label is not damaged under the same conditions.

  The comparison unit 21 compares the image data processed by the image processing unit 19 with reference data, outputs the data to the personal computer 25 and displays the data on the monitor 27.

  Here, an experiment was performed in which the intensity of fluorescence generated when a certain area of light was applied to the PET bottle and the OPS film was measured. The results will be described with reference to the graph of FIG.

  The OPS film described in the graph of FIG. 4 has a thickness of about 50 μm and is used as a transparent substrate fill for the label 9. The PET bottle shown in the graph of FIG. 4 is an empty bottle container used in the present embodiment, and irradiates light with the label 9 attached to the empty bottle when the light is individually irradiated with light. The fluorescence intensity (OPS film + PET bottle) was measured. In FIG. 4, the vertical axis represents the wavelength of each irradiated light, and the horizontal axis represents the intensity of the generated fluorescence. As a measuring instrument, a fluorescence spectrophotometer (manufactured by Hitachi, Ltd .: F3000) was used.

  The excitation wavelength was 375 nm, the excitation / fluorescence wavelength measurement interval was 5 nm, the scan speed was 240 nm / min, and the response was 2 seconds.

  As is clear from FIG. 4, it is clear that fluorescence (wavelength around 430 nm in the near ultraviolet region) is emitted in any of the PET bottle, the OPS film, and the OPS film + PET bottle. It can also be seen that the fluorescence intensity in the case of the PET bottle alone is nearly three times the fluorescence intensity of the OPS film + PET bottle. The OPS film + PET bottle is in a state in which the OPS film is attached to the PET bottle. In this case, the fluorescence intensity was higher than that of the single OPS film and lower than that of the single PET bottle.

  Therefore, when a label made of an OPS film is attached to a PET bottle (OPS film + PET bottle), if the label is damaged, strong fluorescence is received from the PET bottle. It is clear that it can be detected.

  Next, a label inspection method according to the present embodiment will be described. When the beverage bottle 11 is transported to the inspection position on the transport path 13, the label inspection according to the present embodiment is started.

  In label inspection, as shown in FIGS. 1 to 3, ultraviolet rays are irradiated from the ultraviolet irradiation unit 3 toward the label 9 of the beverage bottle 11.

  As shown in FIG. 3, when the beverage bottle 11 and the label 9 are irradiated with ultraviolet rays, fluorescence is generated, and the fluorescence is received as a fluorescent image by the camera 5 through the light transmission hole 17 of the ultraviolet irradiation unit 3.

  For example, when there is damage 29 on the label 9 as shown in FIG. 5, the fluorescence intensity of the damaged portion 29 appears strong because the fluorescence of the PET bottle is stronger than the fluorescence of the label 9 in this embodiment. Therefore, as shown in FIG. 6, in the pixel of the image sensor of the camera 5, the shaded portion 29a is received as a strong fluorescent region.

  Further, as shown in FIG. 7, even when the label is shifted, as shown in FIG. 8, the fluorescent image appears as a strong fluorescent region with the hatched portion 29a.

  When the image signal of the fluorescence image is transmitted from the camera 5 to the control unit 7, the image processing unit 19 assigns an address to the pixel and turns on “1” / off “0” in which each pixel is divided by the intensity of the fluorescence. Is binarized. Then, it is compared with the reference data recorded in the memory 23. The reference data is fluorescence image data obtained by measuring a beverage bottle 11 whose label is not damaged.

  The comparison unit 21 compares the fluorescence image data with the reference data based on the pixel address. For example, when the pixel in the predetermined area is “1” and the reference data is “0”, it is detected as abnormal, If an abnormality is detected, a notification is sent.

  In addition, each examined fluorescent image is displayed on the monitor 27 and data is output to the personal computer 25.

  According to this embodiment, it is not necessary to form a label inspection layer on the surface of the transparent substrate film as in the prior art, and the label 9 can be easily manufactured.

  According to this embodiment, since the damage of the label 9 is determined from the comparison with the reference data, it is difficult to be influenced by the printed color ink in the label inspection.

  PET bottles (polyethylene terephthalate bottles) emit high intensity fluorescence when irradiated with ultraviolet rays, and OPS films (biaxially stretched polystyrene film) emit low intensity fluorescence compared to PET bottles. When the OPS film substrate label is attached to a (polyethylene terephthalate) bottle, the difference in fluorescence from the PET bottle is large, and label damage is easy to detect.

  The blue light emitting diode 15 is used for ultraviolet irradiation, and the blue light emitting diode 15 generates little heat and has a stable light quantity, and is easy to maintain.

  Since the brightness and darkness of the fluorescent image is digitized in binary, image processing is easy and the damaged part is easy to understand.

  Furthermore, in the present embodiment, since the camera 5 is provided on the ultraviolet irradiation side, it can be detected without being affected by the contents of the bottle as compared with the case where the beverage bottle is transmitted, so that the detection accuracy is high.

  Next, a second embodiment of the present invention will be described with reference to FIG. In the embodiment described below, the same reference numerals are given to the portions having the same operational effects as those of the first embodiment described above, and detailed description thereof is omitted.

  In the label inspection method according to the second embodiment, the transparent base film of the label 9 contains an ultraviolet absorber, and the ultraviolet image obtained by irradiating the bottle container 11 with ultraviolet rays from the ultraviolet irradiation unit 3 is transmitted. Compared with the light and dark when the transparent label is not damaged, the damage of the transparent label is detected.

  In the present embodiment, the ultraviolet image received by the camera 5 has a low ultraviolet intensity at the portion where the label is present and a strong ultraviolet ray at the damaged portion of the label. By comparing with the reference data when there is no damage, it is possible to easily detect the presence or absence of damage and the damaged portion.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. For example, in the first embodiment, the arrangement of the camera 5 and the ultraviolet irradiation unit 3 is as shown in FIG. 10, in which an ultraviolet irradiation unit is arranged on the side of the camera so that the fluorescence caused by the irradiation of ultraviolet rays is received by the camera. good.

  Moreover, in 1st Embodiment, the ultraviolet irradiation from the ultraviolet irradiation part 3 may irradiate a ultraviolet-ray in a backlight form so that it may permeate | transmit the drink bottle 11 like 2nd Embodiment. .

It is a schematic block diagram of the label inspection apparatus which concerns on embodiment of this invention. It is a top view which shows arrangement | positioning of the camera and ultraviolet irradiation part in a label test | inspection. It is a side view which shows the relationship between the ultraviolet irradiation to the container containing a drink with which the label was mounted | worn, and a camera. It is a graph which shows the relationship of the fluorescence intensity in a label and a drink bottle (PET bottle). It is a front view of the container containing a drink which shows the example of the damaged label. It is a top view which shows the fluorescence image of the drink bottle shown in FIG. It is a front view of the container with a drink which shows the example of the label from which the position shifted. It is a top view of the pixel which carried out the fluorescence image process of the drink bottle shown in FIG. It is a front view which shows the label test | inspection which concerns on 2nd Embodiment. It is a top view which shows the relationship between the camera which concerns on other embodiment, and an ultraviolet irradiation part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Label inspection apparatus 3 Ultraviolet irradiation part 5 Camera 7 Control part 9 Label 11 Drinking bottle (transparent resin container)
15 Blue light emitting diode 19 Image processing unit 21 Comparison unit 23 Memory

Claims (8)

  A label inspection method for inspecting damage to a transparent label mounted on the outer periphery of a transparent resin container, wherein the transparent label is formed by printing on a transparent substrate film that emits fluorescence having a different intensity from that of the transparent resin container by irradiation of ultraviolet rays It is possible to detect the damage of the transparent label by comparing the brightness and darkness of the fluorescent image obtained by irradiating ultraviolet rays toward the transparent label mounted on the transparent resin container with the brightness and darkness when the transparent label is not damaged. A characteristic label inspection method.   The label inspection method according to claim 1, wherein the transparent resin container is made of polyethylene terephthalate, and the transparent substrate film is a polystyrene film.   The label inspection method according to claim 2, wherein the ultraviolet light is light of a blue light emitting diode.   The fluorescent image is received by a CCD camera, and is expressed as a binary value of “0” and “1” based on the amount of light received by each pixel in the image sensor of the CCD camera. By comparing the fluorescent image numerically, the damaged area of the label The label inspection method according to claim 3, wherein:   The label inspection method according to claim 4, wherein the CCD camera is provided on the ultraviolet irradiation side and receives light emitted from the surface of the transparent label by the ultraviolet irradiation.   A label inspection method for inspecting damage to a transparent label mounted on the outer periphery of a transparent resin container, wherein the transparent label is formed by printing on a transparent substrate film, and the transparent substrate film contains an ultraviolet absorber. Detects damage to the transparent label by comparing the brightness and darkness of the UV image obtained by irradiating and transmitting the UV light toward the transparent label attached to the transparent resin container, compared to the brightness and darkness when the transparent label is not damaged. A label inspection method characterized by that.   The label inspection method according to claim 6, wherein the ultraviolet light is light of a blue light emitting diode.   The ultraviolet image that has passed through the transparent resin container is received by the CCD camera. Based on the amount of light received by each pixel in the image sensor of the CCD camera, the binary image is expressed as “0” and “1”, and the ultraviolet image is expressed numerically. 8. The label inspection method according to claim 7, wherein the damaged area of the label is displayed by comparison.

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