JP4753019B2 - Neck ring inspection device and neck ring inspection method - Google Patents

Description

  The present invention relates to a neck ring inspection apparatus and a neck ring inspection method for inspecting the shape of a neck ring formed at the mouth of a plastic bottle.

A neck ring is formed at the mouth of a container manufactured by blow molding such as a PET bottle (see, for example, Patent Document 1). Since this neck ring is likely to be chipped, the shape is inspected.
Japanese Patent Laid-Open No. 10-230950

  However, since the conventional inspection generally determines whether or not there is an abnormality (such as a chip) in the shape by visual inspection, it is a sample inspection that selects and inspects a predetermined number of manufactured containers. However, it can only be applied, and it has been difficult to perform 100% inspection. For this reason, a container in which an abnormality such as a chip in the shape of the neck ring has occurred may not be excluded as a defective product.

  The present invention has been made to solve the conventional problems, and an object of the present invention is to provide a neck ring inspection apparatus and a neck ring inspection method capable of performing a complete inspection with ease and accuracy.

The neck ring inspection apparatus of the present invention is for inspecting the shape of a neck ring formed at the mouth of a plastic bottle, and a light projecting means for projecting light from the bottom direction of the plastic bottle to the neck ring. A shooting unit that shoots a neck ring that is light-projected by the light projecting unit and generates video data, and is generated by the shooting unit. Multi-gradation video data generating means for generating multi-gradation video data according to the shade based on the video data to be reproduced, and multi-gradation according to the shade generated by the multi-gradation video data generation means Based on the video data, it is configured to include determination means for determining whether or not the neck ring has a predetermined reference shape.

  With this configuration, the shape of the neck ring is specified by video data obtained by photographing the neck ring on which the light is projected, and whether or not the specified shape has a predetermined reference shape, in other words, Then, it is automatically determined whether or not the PET bottle is a non-defective product. For this reason, it is possible to easily perform 100% inspection without requiring manpower. In addition, since the photographing unit is arranged at a position facing the light projecting unit across the neck ring, the brightness difference between the neck ring part and the other part in the video data becomes large, and the outline of the neck ring becomes clear. Thus, the inspection accuracy can be improved.

In determining whether the neck ring has a predetermined reference shape, since multi-gradation video data is used, detection of a small lack of the neck ring represented by a small difference in shading is detected. This makes it possible to conduct more precise inspections.

  In addition, the neck ring inspection apparatus of the present invention includes a discharge unit that discharges the PET bottle as a defective product when the determination unit determines that the neck ring does not have a predetermined reference shape. It becomes composition.

With this configuration, it is possible to easily remove defective PET bottles.
In addition, the neck ring inspection apparatus of the present invention includes a transport unit that transports the neck ring to a light projecting area of the light projecting unit and an image capturing area of the image capturing unit.

  With this configuration, the neck ring is automatically arranged in the light projecting area by the light projecting means and the image capturing area by the image capturing means, so that it is possible to perform 100% inspection more easily.

  In addition, the neck ring inspection apparatus of the present invention is configured to include a light shielding unit that prevents light other than light from the light projecting unit from being projected onto the neck ring.

  With this configuration, light (external light) other than the light from the light projecting unit is prevented from being projected onto the neck ring, and a more precise inspection can be performed.

  Moreover, the neck ring inspection apparatus of this invention becomes a structure where the said light projection means projects white light (for example, illumination light of LED).

  With this configuration, inspection can be performed even when the neck ring is formed of a transparent member.

Further, the neck ring inspection method of the present invention is to inspect the shape of the neck ring formed in the mouth portion of the PET bottle, and a light projecting step of projecting light to the neck ring by a light projecting unit, A photographing step of photographing a neck ring in which light is projected by the light projecting step by a photographing unit disposed at a position facing the light projecting unit across the neck ring, and generating a video signal, and the photographing step A multi-gradation video data generation step for generating multi-gradation video data corresponding to the light and shade based on the video signal generated by A determination step for determining whether or not the neck ring has a predetermined reference shape based on the key image data .

  According to the present invention, whether or not a PET bottle is a good product is determined based on video data obtained by photographing a neck ring to which light is projected by photographing means arranged at positions facing each other across the neck ring. Since the determination is made automatically, it is possible to perform a complete inspection simply and accurately without requiring human intervention.

  Hereinafter, a neck ring inspection apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a top view of the neck ring inspection apparatus according to the embodiment of the present invention, FIG. 2 is a side view in the AA direction of FIG. 1, and FIG. 3 is a side view in the BB direction of FIG. These neck ring inspection apparatuses shown in FIGS. 1 to 3 inspect the shape of the crystallized white neck ring 601 formed at the mouth of the PET bottle 600. The neck ring inspection apparatus includes a light projecting unit 100, a camera 200, support units 301, 302, 306, 307, 308, a Delrin plate 310, a casing 350, and turrets 401, 402, 403.

  The light projecting unit 100 projects light from the bottom direction of the plastic bottle 600 to the neck ring 601 via the Delrin plate 310. The camera 200 is disposed at a position facing the light projecting unit 100 with the neck ring 601 interposed therebetween, and performs imaging to generate video data.

  The support unit 301 supports the camera 200 so as to be movable in the left-right direction on the paper surface of FIG. The support portion 302 supports the support portion 301 so as to be movable in the front and back direction on the paper surface of FIG. The support unit 306 supports the support unit 302 so as to be movable in the vertical direction on the paper surface of FIG. The support portions 307 and 308 support the end portion of the support portion 306, respectively. The camera 200 is supported by these support portions 301, 302, 306, 307, and 308, so that it can move in the left-right direction, the front-back direction, and the vertical direction on the paper surface of FIG.

  The casing 350 blocks outside light so that light (external light) other than light from the light projecting unit 100 is not projected onto the neck ring 601. Note that when the neck ring inspection apparatus is disposed in a dark room and no external light is projected onto the neck ring 601, the housing 350 may not be configured to block external light. The turrets 401, 402, and 403 convey the plastic bottle 600 while rotating. The transported plastic bottle 600 is transported by the turret 401, and then fitted into the concave portion 404 of the turret 402 and transported to the inspection position, and further transported and transported by the turret 403.

  A block diagram of the neck ring inspection apparatus is shown in FIG. The neck ring inspection apparatus illustrated in FIG. 4 includes a light projecting unit 100, a camera 200, a controller 500 that inspects the shape of the neck ring 601 based on video data generated by the camera 200, and a pet that is a defective product. A discharge unit 550 for discharging the bottle 600.

  The light projecting unit 100 is configured to uniformly project light to the neck ring 601. Further, the light projecting unit 100 can project white light (for example, LED illumination light). Even when the neck ring 601 is not crystallized and is formed of a transparent member by projecting white light by the light projecting unit 100, the projected light passes through the neck ring 601. The camera 200 can be reached.

  The camera 200 shoots from a position facing the light projecting unit 100 with the neck ring 601 interposed therebetween, and generates video data. For example, the camera 200 has a structure in which photodiodes that are charge-coupled elements are arranged, accumulates charges corresponding to the amount of light from the light projecting unit 100 using these photodiodes, and video data corresponding to the accumulated amount. Is generated. Video data generated by the camera 200 is sent to the controller 500.

  The controller 500 includes a frame memory 501, a monitor 502, a CPU 503, and a memory 504. The frame memory 501 stores video data from the camera 200. The monitor 502 performs video display based on video data read from the frame memory 501 under the control of the CPU 503.

  The CPU 503 acquires in advance video data of a neck ring 601 of a non-defective PET bottle 600, in other words, a neck ring 601 having a normal shape. For example, the light projecting unit 100 projects light onto the neck ring 601 of the plastic bottle 600 that is determined to be a good product in advance, and the CPU 503 shoots the neck ring 601 of the plastic bottle 600 that is a good product. Acquire the generated video data. Furthermore, the CPU 503 generates multi-gradation (for example, 256 gradations) video data (reference video data) corresponding to the density for each pixel based on the acquired video data, and stores it in the memory 504.

  In addition, when the video data obtained by photographing the neck ring 601 of the PET bottle 600 to be inspected is stored in the frame memory 501, the CPU 503 multi-levels corresponding to the shade for each pixel based on this video data. Video data (inspection video data) of a key (the same number of gradations as the reference video data) is generated. Further, the CPU 503 compares the inspection video data with the reference video data to derive a difference, and if the difference is not within the predetermined range, a signal indicating that the PET bottle 600 is a defective product (defective product detection signal). Is output to the discharge unit 550.

  The discharge unit 550 is provided at a position downstream of the turret 403 in the conveyance path of the PET bottle 600, and when this defective product detection signal is input, at the timing when the PET bottle 600 that is a defective product has been transported to the near side. The operation of ejecting air and discharging the PET bottle 600 which is the defective product is performed. The neck ring inspection device is provided with means (not shown) for blocking external light to the PET bottle 600 at least at the inspection position.

  About the neck ring test | inspection apparatus comprised as mentioned above, the operation | movement at the time of the test | inspection of the neck ring 601 of the PET bottle 600 is demonstrated. FIG. 5 shows a flowchart of the operation at the time of inspection of the neck ring 601 of the PET bottle 600 of the neck ring inspection apparatus.

  The PET bottle 600 to be inspected is transported to a predetermined position (inspection position) so that the neck ring 601 is disposed in the light projection area of the light projecting unit 100 and the imaging area of the camera 200 (S101).

  The light projecting unit 100 projects light to the neck ring 601 (S102). A part of the light projected by the light projecting unit 100 and reaching the neck ring 601 is blocked by the neck ring 601, but the other light reaches the camera 200. The camera 200 captures the neck ring 601 on which the light is projected, and generates video data (S103). The generated video data is sent to the controller 500.

  When the controller 500 acquires video data obtained by photographing the neck ring 601 of the PET bottle 600 to be inspected, the controller 500 generates multi-tone inspection video data corresponding to the shade for each pixel based on this video data. (S104). Next, the controller 500 compares the generated inspection video data with reference video data stored in advance, and derives a difference between the inspection video data and the reference video data (S105). Further, the controller 500 determines whether or not the derived difference is within a predetermined range (S106).

  An example of an image corresponding to the reference image data (reference image) and an image corresponding to the inspection image data (inspection image) is shown in FIG. For example, the controller 500 determines the pixel at the same position of the video corresponding to the reference video data (reference video shown in FIG. 6A) and the video corresponding to the inspection video data (inspection image shown in FIG. 6B). The difference in gradation frequency is calculated. Further, the controller 500 counts the number of pixels in which the difference in gradation frequency is equal to or greater than a predetermined value. If the result of the count is equal to or greater than the predetermined number, the difference between the inspection video data and the reference video data is predetermined. It is determined that it is not within the range.

  Alternatively, as another analysis means, the controller 500 extracts a pixel in which a difference in gradation frequency from an adjacent pixel is equal to or greater than a predetermined value in an image corresponding to the reference image data (reference image shown in FIG. 5A). As a result, the contour of the neck ring 601 in the reference image is derived, and the difference in gradation frequency between adjacent pixels in the video corresponding to the test video data (the test video shown in FIG. 5B) is equal to or greater than a predetermined value. By extracting a certain pixel, the boundary of the neck ring 601 in the inspection image can be derived and inspected. Here, the boundary of the neck ring 601 in the reference image represents the contour of the neck ring 601 of the non-defective PET bottle 600, and the boundary of the neck ring 601 in the inspection image is the contour of the neck ring 601 of the PET bottle 600 to be inspected. Represents. Further, when the difference between the contour of the neck ring 601 of the non-defective PET bottle 600 and the contour of the neck ring 601 of the PET bottle 600 to be inspected is not within a predetermined range, the controller 500 displays the inspection video data and the reference video data. It is determined that the difference is not within the predetermined range.

  Alternatively, the controller 500 classifies each pixel of the video corresponding to the reference video data (the reference video shown in FIG. 5A) into a dark region and a light region according to the gradation frequency, and according to the inspection video data. Each pixel of the video (inspection image shown in FIG. 5B) is classified into a dark region and a light region according to the gradation frequency. Here, the boundary between the dark region and the light region in the reference image represents the outline of the neck ring 601 of the non-defective PET bottle 600, and the boundary between the dark region and the light region in the inspection image is the neck of the PET bottle 600 to be inspected. The outline of the ring 601 is represented. Further, when the difference between the contour of the neck ring 601 of the non-defective PET bottle 600 and the contour of the neck ring 601 of the PET bottle 600 to be inspected is not within a predetermined range, the controller 500 displays the inspection video data and the reference video data. It is determined that the difference is not within the predetermined range.

  When it is determined in S106 that the difference is within the predetermined range, the shape of the neck ring 601 of the PET bottle 600 to be inspected matches or substantially matches the shape of the neck ring of the PET bottle 600, which is a non-defective product, and is treated as a non-defective product. It has a shape (reference shape) that can be used. In this case, the operation after the transportation of the plastic bottle 600 (S101) is repeated to inspect the next plastic bottle 600.

  On the other hand, if it is determined in S106 that the difference is not within the predetermined range, the neck ring 601 of the PET bottle 600 to be inspected has some abnormality such as a chip and does not have a reference shape. In this case, the controller 500 outputs a defective product detection signal indicating that the PET bottle 600 is a defective product to the discharge unit 550 (S107). When the defective product detection signal is input, the discharge unit 550 ejects air at a timing when the defective plastic bottle 600 is transported to the front, and discharges the defective plastic bottle 600. Do.

  As described above, in the neck ring inspection apparatus of this embodiment, the light projecting unit 100 projects light onto the neck ring 601 of the PET bottle 600 to be inspected, and the camera 200 sandwiches the neck ring 601 and projects the light projecting unit 100. The neck ring 601 is photographed from a position facing the. Then, the controller 500 compares the video data obtained by this photographing with the reference video data corresponding to the good plastic bottle 600 that is held in advance. If the difference is not within the predetermined range, the discharge unit 550 causes the bottleneck. The plastic bottle 600 having the ring 601 is discharged as a defective product. For this reason, it is possible to easily perform 100% inspection without requiring manpower. Further, since the camera 200 is disposed at a position facing the light projecting unit 100 with the neck ring 601 interposed therebetween, the brightness difference between the neck ring 601 portion and other portions in the video data is increased, and the contour of the neck ring 601 is increased. Becomes clear and the inspection accuracy can be improved.

  As described above, the neck ring inspection apparatus and the neck ring inspection method according to the present invention have an effect that it is possible to perform 100% inspection easily and accurately, and are useful as a neck ring inspection apparatus and a neck ring inspection method. is there.

It is a top view of a neck ring inspection apparatus. It is a 1st side view of a neck ring inspection apparatus. It is a 2nd side view of a neck ring inspection apparatus. It is a block diagram of a neck ring inspection apparatus. It is a flowchart of the operation | movement at the time of the neck ring test | inspection of a neck ring test | inspection apparatus. It is a figure which shows an example of a reference | standard image | video and a test | inspection image | video.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Light projection part 200 Camera 301,302,306,307,308 Support part 310 Delrin board 401,402,403 Turret 404 Recessed part 500 Controller 501 Frame memory 502 Monitor 503 Memory 504 CPU
550 Discharge unit 600 PET bottle 601 Neck ring

Claims (6)

A neck ring inspection device for inspecting the shape of a neck ring formed at the mouth of a plastic bottle,
Projecting means for projecting light from the bottom direction of the PET bottle to the neck ring;
An imaging unit that is disposed at a position facing the light projecting unit across the neck ring, captures the neck ring on which light is projected by the light projecting unit, and generates video data;
Multi-gradation video data generation means for generating multi-gradation video data corresponding to the shade based on the video data generated by the photographing means ;
Determining means for determining whether or not the neck ring has a predetermined reference shape based on multi-gradation video data corresponding to the shade generated by the multi-gradation video data generating means ; A neck ring inspection apparatus comprising: When the neck ring is determined not to have a reference shape predetermined by the determination means, the neck according to claim 1, characterized in that it has a discharge means for discharging the PET bottle as defective Ring inspection device. 3. The neck ring inspection apparatus according to claim 1, further comprising a transport unit configured to transport the neck ring to a light projecting region of the light projecting unit and a photographing region of the photographing unit. Neck ring inspection apparatus according to any one of claims 1 to 3, characterized in that it has a light shielding means for preventing light other than light from said light projecting means on said neck ring is projected. It said light projecting means, the neck ring inspection apparatus according to any one of claims 1 to 4, characterized in that for projecting white light. A neck ring inspection method for inspecting the shape of a neck ring formed at the mouth of a plastic bottle,
A light projecting step of projecting light onto the neck ring by a light projecting means;
Photographing the neck ring in which light is projected by the light projecting step by the photographing means arranged at a position facing the light projecting means across the neck ring, and generating a video signal;
A multi-gradation video data generation step for generating multi-gradation video data corresponding to the shade based on the video signal generated by the photographing step ;
A determination step for determining whether or not the neck ring has a predetermined reference shape based on the multi-gradation video data corresponding to the shade generated by the multi-gradation video data generation step ; A neck ring inspection method comprising:

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