JP4274006B2 - Container foreign matter detection device - Google Patents

Description

  The present invention relates to an in-container foreign matter detection device that detects foreign matter that has settled in a container from an image of the container obtained by imaging means by irradiating illumination light to the container in which the liquid is sealed.

  The main foreign substances mixed in a container sealed with drinking water or the like are a part of a container material or a part of a part filled with a liquid of contents at the stage of forming and manufacturing the container. There is almost no foreign matter mixed in the container, but there is a possibility of adverse effects on the human body, so it is required to reliably remove foreign matter mixed containers from the production line regardless of the frequency of occurrence. I am inspecting.

  The conventional 100% inspection relies on human visual inspection. However, it is particularly difficult to detect and the presence of precipitation is most often a precipitated foreign matter, which is sometimes overlooked.

  The reason for oversight is that the thickness changes at the bottom and there is a step due to the convenience of container molding, the container bottom itself is like a lens with a complicated shape, and if the color of the contents and the foreign matter are close, This is because it is difficult to make a difference in brightness from surrounding contents, and it is difficult to distinguish.

  Therefore, instead of human visual observation, as shown in FIG. 9, the illumination device 2 irradiates the bottom of the transparent container 1 filled with liquid with illumination light, and the image of the container bottom is captured by the imaging camera 3 incorporating the image sensor. There is a technique for detecting foreign matter mixed in the container.

In this prior art, an image is obtained by the light reflection method, and the light intensity of the reflected light from the contents in the container used as the background and the light intensity of the reflected light from the surface of the foreign matter in the background are shaded by the image sensor 3. it is determined as the difference.

  The principle of this technique is that, with respect to the gray value by the image sensor 3, if one has a large difference in the gray value with respect to the other, the difference from the threshold value used as a criterion for the determination can be increased. It is easy to distinguish.

  In addition, there exists the following patent document 1 as what shows the said prior art.

JP 2001-201457 A

  In the above prior art, when the image is obtained by the light reflection method in a state where the contents and the foreign matter are close in color, the brightness of the reflected light of the content and the foreign matter becomes equal, and the content and foreign matter that can be detected by the image sensor The difference between the gray values becomes small and difficult to discriminate.

In addition, the settled foreign matter is granular and not flat, and part of it is in contact with the bottom of the container and many other parts are away from the container wall, and it is completely in close contact with the container wall. Almost no.

  If the contents are a suspension, the part of the foreign material away from the bottom of the container will be difficult to see, and only the part of the foreign material in contact with the bottom of the container will appear small in dots, making it difficult to identify it as a foreign object. turn into.

  Accordingly, an object of the present invention is to provide an in-container foreign matter detection device capable of stably and correctly detecting foreign matter mixed in a container regardless of the type, even when the colors of the contents and the foreign matter are close. There is.

A feature of the device of the present invention that achieves the above object is that a transparent container in which a liquid that is a medicine or a beverage is sealed is irradiated with illumination light from an illumination device, and an image of the container obtained by an imaging means is obtained. in container foreign matter detecting system in which the image processing unit detects an opaque precipitate foreign matter precipitated by image processing on the bottom of the container, wherein the liquid is a suspension containing fine particles, the image pickup means is the Focusing on the bottom of the container, on the bottom side of the container, the illumination device is disposed on the side of the container so as to irradiate from the side of the container toward the bottom of the container, and the image information processing The unit detects precipitated foreign matter from the difference in brightness between the bright part formed by irregularly reflecting the illumination light irradiated by the illumination device by the minute particles and the dark part formed by being blocked by the opaque precipitated foreign matter. There is to do.

  And as an illuminating device, the reflecting plate and light diffusing plate which irradiate the side part of a container with the illumination light which a light source emits are included.

  According to the present invention, the contrast in the image due to the uneven distribution of the amount of light generated by light refraction or reflection based on the shape of the container is suppressed, and the inside of the container is mixed regardless of the color of the contents or foreign matter. Can be detected stably and correctly.

According to the present invention, the illumination light irradiated from the side of the container is irregularly reflected on the surface of the fine particles in the contents, and the traveling direction of the illumination light from the contents through the container bottom surface to the imaging means is dispersed in all directions, simultaneously with the uniform light amount distribution of the illumination light by undulations in the bottom of the container by the dispersed light, since the precipitates foreign materials in the container bottom shielding the illumination light to be passed, the luminance of the precipitation foreign matter pieces plants imaging means to obtain the The brightness of the illumination light at the place other than the precipitated foreign matter is maintained at a uniform level. Thus, the difference between the gray value of an image in individual plants and other point of the precipitation foreign matter rather large, easy to determine the precipitation foreign matter.

  Hereinafter, the present invention will be described based on the embodiments shown in the drawings. An example using transparent PET as a container is shown.

  FIGS. 1 to 3 show a first embodiment. As shown in FIG. 1, the transparent containers 1 made of PET are sequentially and continuously transported on the transport conveyor 11A on the carry-in side. The container 1 is already filled with a liquid content LQ, which is mainly a medicine or beverage, and is further sealed with a container lid 4.

  Precipitated foreign matter detection is performed immediately after the container lid 4 is sealed. Usually, in the step of detecting foreign matter, there is no printed matter that becomes an optical obstacle on the outer surface of the container 1, and the printed matter is often attached only to the container 1 that has become non-defective in foreign matter detection. In addition, the container 1 and the contents LQ (liquid sealed in the container) targeted in the present embodiment are both transparent, but are not limited to colorless and transparent, are colored and transparent, and are opaque in general ambient light Even in such a case, it can be set as a foreign object detection target according to the degree of light transmission.

The container 1 in which foreign matter is confirmed to be mixed is removed from the carrying conveyor 11B on the carry-out side, or a defect identification mark serving as a mark is added to a conspicuous position of the container 1 so as to be discharged in a subsequent process.
A description of the means for adding the defect identification mark is omitted.

  A pair of grip conveyors 5A and 5B that sandwich the both side surfaces 1a of the container 1 are provided on the carry-in side conveyer 11A and the carry-out side conveyer 11B. The container 1 is mounted to the vicinity immediately before the DP, and is transferred to the grip conveyors 5A and 5B that sandwich both side surfaces 1a of the container 1. For delivery of the container 1, a side area of 100 (mm) to 500 (mm) is provided.

  The container 1 is sandwiched between grippers 5A and 5b of the grip conveyors 5A and 5B, and the upper lid side and the lower bottom side are open.

  The grip conveyors 5A and 5B support rubber or resin grippers 5a and 5b with a chain, and a plurality of grippers 5a and 5b are arranged by the length of the chain. Although not shown, the chain is driven through a sprocket while controlling the speed with a motor.

  The grip conveyors 5A and 5B are driven synchronously so that the inner grippers 5a and 5b sandwich the side surface 1a of the container 1 and deliver it to the carry-out conveyor 11B. The grippers 5a and 5b are slightly deformed so as to conform to the shape of the container 1 at the place where it contacts the container 1, and the container 1 is transported while maintaining its posture without dropping due to the frictional resistance of the contact portion.

  At the deposit foreign matter inspection position DP, the light from the illumination light source 6 having a halogen lamp passes through the light guide 7 and is provided under the grip conveyors 5A and 5B as shown in FIG. The irradiation unit (illumination light irradiating means) 2 passes through the diffusion plate 12 and irradiates from the side of the container 1 diagonally upward toward the bottom of the container 1.

  Of course, the light guide 7 is installed so that the conveyance of the container 1 is not hindered by the irradiation from the side obliquely above. The number is two directions or four directions. Although FIG. 2 illustrates two directions, one of the two directions may be further divided into four directions.

  The illumination light source 6 is selected from a fluorescent lamp, LED, EL, incandescent lamp, metal halide lamp, infrared lamp, ultraviolet lamp, etc. in addition to a halogen lamp.

  The inside of the light guide 7 is in a state where several hundred optical fibers are bundled, and the optical fibers are divided by the illumination light irradiation unit 2, and the ends of the optical fibers are fixed in a straight line. The length of the straight line is determined according to the size of the container 1. At the tip of the optical fiber, the light is irradiated with a certain spread angle, the travel direction is further expanded by the diffusion plate 12, refracted once at the container side surface 1a, passes through the inside of the container 1, and refracted again at the container bottom 1b. While proceeding below the container 1.

  An imaging camera (imaging unit) 3 that images the container 1 is disposed below the inspection position DP for the deposited foreign matter, and the imaging camera (imaging unit) 3 includes an imaging element.

  The container presence / absence detection sensor 13 detects that the container 1 to be inspected sandwiched between the grip conveyors 5A and 5B has arrived at the detection position DP. As the type of the container presence / absence detection sensor 13, a transmitted light type or an ultrasonic type may be used in addition to the reflected light type.

  The inspection position DP of the precipitated foreign matter and its surroundings are surrounded by a light-shielding cover (not shown) so that light from the surroundings that becomes an optical disturbance to the container 1 and the imaging camera 3 is blocked to detect stable foreign matters. Yes.

  The detection result of the container presence / absence detection sensor 13 is grasped by the main computing unit 22 via the I / O interface 21 shown in the detection device control unit 20 of FIG. 3, and the imaging camera 3 is detected by the shutter signal control unit 23 and the imaging camera controller 24. This is reflected in the shutter signal. Based on the shutter signal, the imaging camera 3 captures an image of the container 1 and temporarily stores it in the storage device of the image information processing unit 26 that performs image processing from the imaging camera controller 24 via the camera interface 25. Perform the extraction process.

  The captured image and the video that has already been processed are displayed on the image processing monitor 27. Further, the start, stop, and error of the apparatus are managed by the operation switch 28 and the display lamp 29, and the operation status management of the entire apparatus including the management and image processing of the video is performed by the main arithmetic unit 22 and the main storage unit 30. ing. The operating status of the entire apparatus is displayed on the monitor 31.

  Hereinafter, detection of precipitated foreign matter will be described with reference to FIG.

  FIG. 2B is an enlarged cross-sectional view of the elliptical portion of FIG. 2A, and the liquid content LQ such as a beverage may be completely transparent, but contains minute particles 9. There are many, and the content rate is various.

  In the liquid content (suspension) LQ including these fine particles 9, the light is irradiated from the lateral direction with respect to the optical axis of the imaging camera 3, that is, the light of the illumination light irradiation unit (illumination light irradiation means) 2. When crossing the axis, the illumination light is irregularly reflected in all directions on the surface of the particle 9, and if the light is irradiated from multiple directions, it is irregularly reflected in more directions on the particle surface and the liquid content (suspension) LQ. Has uniform brightness.

  When the illumination light is irradiated from an obliquely upward direction of the container 1, the traveling direction is widened by the diffusion plate 12, and the light reflected on the surface of the fine particles in the container is captured by the imaging camera 3, the light passing through the container 1 is Since it is divided in all directions, the surface relief pattern is unclear. That is, the entire bottom 1b of the container 1 has uniform brightness.

  In such a situation, if there is a foreign matter SD deposited on the bottom 1b in the container 1, light is blocked only at the location of the foreign matter SD, and the imaging camera 3 captures it as a dark spot with a small luminance. The traveling direction of light spreads in multiple directions mainly on the surface of the diffusion plate 12 and the particles 9, and the traveling direction of light is not changed in multiple directions between the precipitated foreign matter SD and the imaging camera 3.

  Therefore, the outline of the precipitated foreign matter SD is captured as it is, and if the imaging camera 3 is focused on the bottom 1b of the container 1, a clear image of the precipitated foreign matter SD can be obtained.

  When the optical axes of the illumination light irradiation unit (illumination device) 2 and the imaging camera 3 are matched, only the luminance near the center of the illumination light irradiation unit (illumination device) 2 is increased, while the peripheral luminance is decreased and foreign matter is reduced. Not only is it difficult to discriminate from SD, but also the undulating pattern on the surface of the container 1 appears clearly, making it difficult to detect the foreign matter SD.

  Therefore, it is preferable that light is irradiated from the lateral direction with respect to the optical axis of the imaging camera 3 and intersects with the optical axis of the illumination light irradiation unit (illumination device) 2.

  When another illumination light irradiation unit (illumination device) is added around the imaging camera 3, the reflected light from the foreign object SD is captured by the imaging camera 3, the brightness of the foreign object SD increases, and the foreign object SD is discriminated. Therefore, it is preferable not to add another illumination light irradiation unit (illumination device) that causes the imaging camera 3 to capture reflected light from the foreign matter SD.

  As shown in FIG. 4, in the image IM, the region where there is no foreign matter is only a bright uniform background BS. However, when the foreign matter SD is present, the black spot of the image SDa of the foreign matter SD is present in the bright uniform background BS. It becomes.

  In the conventional technique using the reflection method shown in FIG. 9, it is difficult to discriminate when the reflectance is close, such as when the content liquid and the foreign matter have the same color, but in the present invention, the foreign matter is opaque. As long as this is done, it can be detected regardless of the color of the foreign matter.

Extraction of foreign matter SD by image processing identifies the bottom range of the container 1 serving as a light background, as a threshold an intermediate value of the luminance values of the foreign matter SD pieces plant as a luminance value of the background and dark point, the value above of all replaced brightest white points having a brightness value, by Ru all replaced darkest black points having luminance values lower than the threshold value can be expressed as a binary image of only two luminance values.

  The number of black spots surrounded by white spots in the binary image is calculated. If there are no black spots, it can be determined that the container does not contain foreign substances, and if there are one or more, it can be determined that the container contains foreign substances.

In the case of the container 1 having a small undulation pattern and a smooth surface, as shown in FIG. 5, there is no diffusion plate, and only the scattered light from the fine particles 9 is used, and irradiation with an increased average brightness is performed. Good.

  Since the exposure time by imaging may be about several thousandths of a second, the bottom 1b of the container 1 is imaged while being moved while being conveyed by the grip conveyors 5A and 5B. The imaged container 1 is transported as it is, and is transferred from the grip conveyors 5A and 5B to another transport conveyor 11B on the carry-out side.

  For delivery, a side area of 100 (mm) to 500 (mm) is provided in the same manner as when approaching the inspection position DP for the deposited foreign matter, and it passes through this area and moves away from the inspection position DP. The next container 1 is approached by being transported to the inspection position DP, but before the next container 1 reaches the inspection position DP, the image processing of the previous container 1 is finished.

  From the processing result, the container in which the foreign matter SD is detected is immediately removed from the production line while passing on the conveyor 11B, or is marked and removed in a subsequent process.

  FIG. 6 shows a second embodiment, which is an improved example of the illumination light irradiation path in the illumination light irradiation unit 2 in the first embodiment.

  At the deposit foreign matter inspection position DP, the side surface 1a of the container 1 is held by grippers 5a and 5b, and the illumination light irradiation unit 2 is disposed upward so as not to interfere with the gripper 5a and 5b. The light is reflected by a plate 33 and irradiated on the side surface 1 a of the container 1. The diffusion plate 12 is provided between the illumination light irradiation unit 2 and the reflection mirror 33.

  As shown in FIG. 6, when the diffusing plate 12 is in front of the reflecting mirror 33, the illumination light can be changed more in the irradiation direction, so that a uniform luminance distribution can be obtained even when the container undulation pattern is complicated. .

  FIG. 7 shows a modification in which the diffusion plate 12 is disposed between the reflection mirror 33 and the container 1.

  Thus, when the diffusing plate 12 is behind the reflecting mirror 33, the container relief pattern is medium and the irradiation direction is changed to medium, rather, it is used when it is desired to make the whole brighter according to the liquid type. The luminance can be increased to obtain a more uniform luminance distribution.

  The shape of the reflection mirror 33 may be a curved shape instead of a plate shape so that the irradiation light from the light guide 7 can be concentrated so that only the container 1 can be irradiated.

  By using the reflection mirror 33 in this way, the contact area between the grippers 5a and 5b and the container 1 can be increased, the holding force with respect to the container 1 is increased, and stable container transport is possible.

  In these embodiments, the optical axis of the reflection mirror 33 and the light diffusing plate 12 intersects the optical axis of the imaging camera 3, and the reflection mirror 33 and the light diffusing plate 12 are shown in FIGS. It is a light source that acts as a substitute for the illumination light irradiation unit 2 in the form.

  FIG. 8 shows a third embodiment in which the container transport mode is changed.

  In order to reduce the overall length of the apparatus, a rotary type conveyance is used. The carry-in star wheel 42 having the container mounting table 41 on the lower side adjusts the posture of the container 1, and the main star wheel 43 eliminates the lower table and opens the lower side. In addition, a conveyance guide 44 that supports the side surface 1a of the container 1 along the traveling direction is provided on the outer periphery, and the lower portion of the container neck just below the container lid 4 is suspended by guides 45a and 45b to support the entire container. A precipitation foreign matter detection position DP is provided in the main star wheel 43, and the arrival of the container 1 at the inspection position DP of the foreign matter is detected by a container presence / absence detection sensor (not shown).

  Irradiated light from the illumination light source passes through the light guide 7 and from the inside and outside of the main star wheel 43 through the diffusion plate, and as shown in FIG. Irradiate from multiple directions in the bottom direction. An imaging camera 3 that images the container 1 is disposed below the inspection position DP for precipitated foreign matter (not shown), and is detected by image processing by the detection device controller 20 shown in FIG. 3 similar to the first embodiment. The presence / absence of foreign matter is determined, and whether or not the container is to be discharged is determined according to the determination result.

  Thereafter, the container 1 is received from the guides 45a and 45b by the unloading side star wheel 47 having the container mounting table 46 on the lower side, and the posture is adjusted, and then transferred to the unloading side conveyor 11B.

  In this embodiment, there are many free spaces on the side surface of the container, and irradiation light can be applied from multiple directions.

  As described above, according to the present invention, the difference in light and darkness in the image due to the uneven distribution of the amount of light generated by the refraction or reflection of light coming from the shape of the container is suppressed, and the inside of the container is independent of the color of the foreign matter. Foreign matter mixed in can be detected stably and correctly.

It is a figure which shows the outline of the foreign material detection apparatus in a container which is 1st embodiment of this invention. It is a figure which shows the condition which detects the sediment foreign material with the foreign material detection apparatus in a container of FIG. It is the schematic which shows the electric system in the foreign material detection apparatus in a container of FIG. It is the figure which showed the condition of the foreign material detected with the foreign material detection apparatus in a container of FIG. It is a figure which shows the modification of the foreign material detection apparatus in a container of FIG. It is a figure which shows the outline of the foreign material detection apparatus in a container which is 2nd embodiment of this invention. It is a figure which shows the modification of 2nd embodiment shown in FIG. It is a figure which shows the outline of the foreign material detection apparatus in a container which is 3rd embodiment of this invention. It is a figure for demonstrating a prior art.

Explanation of symbols

1 ... Container
3a ... side of container
3b ... Bottom of container
2 ... Illumination light irradiation part
3 ... Imaging camera
4 ... Container lid
5A, 5B ... Grip conveyor
5a, 5b ... Gripper
6 ... Illumination light source
7 ... Grip conveyor
SD ... Foreign matter
SDa ... Foreign object image
9 ... fine particles
LQ ... Contents
11A ... Carry-in conveyor
11B: Unloading side conveyor
DP ... Inspection position of precipitated foreign matter
13 ... Container presence / absence detection sensor
12 ... Diffuser
20 ... Detection device controller
33 ... Reflective mirror (reflector)

Claims (6)

A transparent container filled with a liquid such as a medicine or beverage is irradiated with illumination light from an illuminating device, and the image information processing unit performs image processing on the image of the container obtained by the imaging means and settles on the bottom of the container In the foreign matter detection device in the container that detects the opaque precipitated foreign matter,
The liquid is a suspension containing fine particles, the imaging means is focused on the bottom of the container toward the bottom of the container, and the illumination device is directed from the side of the container toward the bottom of the container. The image information processing unit is arranged on each side of the container so as to irradiate, and the image processing unit includes a bright part formed by irregularly reflecting the illumination light irradiated by the illumination device by the fine particles, and an opaque precipitate. An in-container foreign matter detection device that detects precipitated foreign matter from a difference in brightness from a dark part formed by being blocked by a foreign matter. The foreign object detection device in a container according to claim 1, wherein a light diffusion plate is installed between the illumination device and the side surface of the container. The foreign object detection device in a container according to claim 1, wherein the illumination device is a reflection plate that reflects light from a light source and irradiates the side of the container with illumination light. . The foreign object detection device in a container according to claim 3, wherein a light diffusion plate is installed between the reflection plate and a side portion of the container. 4. The foreign substance detection apparatus in a container according to claim 3, wherein illumination light is concentrated on the container and irradiated by a curved light reflecting plate. The foreign matter detection apparatus in a container according to claim 1, wherein the imaging means and the illumination device are installed so that their optical axes intersect each other.

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