JP2011127987A - Liquid-level floating foreign substance inspection method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid-level floating foreign substance detection method for eliminating the need for making foreign substances move and drawing the foreign substances in a liquid, by using a large-scale carrying apparatus, and accurately detecting the foreign substance present in a region swollen by a contact between a liquid level and an inner surface of a container, even when the foreign substances are present near the liquid level behind a pull tab. <P>SOLUTION: In the inspection method for detecting a liquid level Le of the liquid L, filling the container 1 having an opening sealed by a cap 2 with the pull tab or the foreign substance floating near the liquid level L, the interior of the container 1 is illuminated from the container bottom side by an illumination 5 disposed under the container 1, and the liquid level Le is illuminated via the liquid L, inside the container 1 to make a portion of the light reaching the liquid level Le enter a location at which the liquid level is swollen in the region in which the liquid level contacts the inner surface of the container 1, and to make the incident light reflected by an interface between the liquid level Le and a gas at the raised region, so that the reflection light reflected by the interface is imaged by a CCD camera 6 disposed on the side of the container 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid level floating foreign matter inspection method and apparatus, and more particularly to a liquid level floating foreign matter inspection method and apparatus for detecting foreign matters floating near the liquid level of a liquid filled in a container.

  2. Description of the Related Art Conventionally, a glass wide-mouth container (wide-mouth jar) that is also used as a cup has been frequently used for filling beverages such as sake. The mouth portion of the cylindrical container-like wide-mouth container is sealed with a cap (lid) made of a metal plate such as aluminum. The cap (lid) of the wide-mouthed container is formed with a substantially ring-shaped portion called a pull tab or pull ring for pulling up with a finger to facilitate opening. This substantially ring-shaped portion extends downward from the outer peripheral edge of the cap (lid) along the outer peripheral surface of the wide-mouth container, and extends downward from the liquid level of the beverage filled in the container.

  In recent years, from the viewpoint of food hygiene management, there has been an increasing demand for inspection devices that can automatically detect foreign substances mixed in beverages, regardless of the visual inspection of workers, even in wide-mouth containers filled with beverages such as sake. ing. In this case, there are a large number of inspection apparatuses for inspecting foreign matters in the liquid and foreign matters deposited on the bottom of the container, and an inspection method has been established.

  On the other hand, in the case of inspecting a foreign substance floating near the liquid surface, since it was considered difficult to inspect the liquid surface in a stationary state, a liquid is disclosed in JP-A-2005-17004 (Patent Document 1) and the like. When the glass bottle (actual bottle) filled with is transported at high speed along the circular path by the mounting part of the rotary inspection table, the liquid level rises obliquely by centrifugal force, and the liquid level After the rise, the liquid surface floating foreign material moves from the low liquid level part to the high part (and the foreign substance existing in the high part before the inclination moves to the lower part), and the light projecting means is changed to the inspection table. The image pickup means is arranged opposite to the light projecting means through the real bottle and moved above the inclined liquid surface of the real bottle conveyed at high speed. To catch the floating foreign matter It has been proposed inspection apparatus to.

  In addition, an inspection apparatus has been proposed in which a container is rotated at high speed using a spin transport device, and the foreign matter is detected by taking an image of the place where the foreign matter floating on the liquid surface is drawn into the liquid by centrifugal force. .

JP 2005-17004 A

  However, as described above, using a large-scale transport device such as a rotary transport device or a spin transport device, the liquid surface is inclined to move the foreign matter, or a measure such as drawing the foreign matter into the liquid by centrifugal force, etc. The foreign matter does not always move as expected, and there is a problem that the foreign matter floating near the liquid surface cannot be detected with high accuracy.

Therefore, the present inventors have earnestly researched an inspection method and apparatus that can accurately detect foreign matters floating near the liquid surface without using a large-scale transport device such as a rotary transport device or a spin transport device. It is what I did.
First, the inventors arranged the illumination and the camera so as to sandwich the container filled with liquid, and transmitted light with the liquid surface being stationary without tilting or rotating the container. The experiment of imaging the liquid surface where the foreign matter floated was repeated. As a result of this experiment, when inspecting foreign matter floating near the liquid surface, the liquid surface suddenly swells at the site where the liquid surface and the container inner surface contact due to the influence of the surface tension of the liquid and the adhesive force between the liquid and the container wall surface, It has been found that the raised portion becomes a dark image, and the foreign matter floating on the liquid surface is hidden in the dark image portion of the raised portion, so that the foreign matter cannot be detected.

As a result of elucidating this phenomenon, the present inventors have found that the reason is as follows.
When light is irradiated from the side surface of the container 1, the light passes through the glass container wall surface and enters the container as shown in FIG. Part of the light incident on the container enters the liquid portion rising on the glass wall surface, passes through the liquid and the glass wall surface in contact with the liquid, and exits from the container wall surface into the air. When entering the liquid from the air in the container, the incident angle (θ1) is larger than the refraction angle (θ2), so that the light is refracted downward as shown in FIG. Since the refractive index of the liquid and the glass wall surface is a slight difference, light takes an optical path close to going straight in the liquid and glass wall surface. When exiting into the air from the glass wall surface, the refraction angle (θ4) when exiting into the air is greater than the incident angle (θ3) at the glass wall surface, so that the light exiting the container 1 travels further downward to the camera 6. Does not enter. As a result, when inspecting foreign matter floating near the liquid level, the liquid level suddenly rises at the site where the liquid level and the inner surface of the container come into contact, and the raised part becomes a dark image, and the dark image portion of the raised part The foreign matter floating on the liquid level is hidden in the liquid and cannot be detected. Therefore, even if the foreign matter is in the center of the liquid level, the foreign matter cannot be detected if the size is such that it is hidden in the dark image portion where the foreign matter has risen.

  The cap (lid) of the wide-mouth container is formed with a substantially ring-shaped portion called a pull tab or pull ring, and this substantially ring-shaped portion extends below the liquid surface. There is also a problem that when there is a foreign object behind the shaped part, the substantially ring-shaped part and the foreign substance cannot be distinguished.

  The present invention has been made in view of the above-described circumstances, and it is not necessary to move a foreign object or draw a foreign object into a liquid using a large-scale transport device such as a rotary transport device or a spin transport device. Even when there is a foreign object near the liquid level behind a ring-like part called a pull ring, the liquid level can be detected accurately with the liquid surface and the inner surface of the container in contact with each other. An object of the present invention is to provide a foreign object detection method and apparatus.

  In order to achieve the above-mentioned object, the liquid level floating foreign substance inspection method of the present invention is an inspection for detecting a foreign substance floating in or near the liquid level of a liquid filled in a container whose mouth is sealed with a cap with a pull tab. In the method, the interior of the container is illuminated from the bottom side of the container by illumination disposed below the container, the liquid surface is illuminated via the liquid in the container, and a part of the light reaching the liquid surface is separated from the liquid surface and the container The incident surface is incident on a portion where the liquid level is raised at a site where the inner surface is in contact, and the incident light is reflected at the interface between the liquid surface and the gas at the raised portion, and the reflected light reflected at the interface is disposed on the side of the container. The image is picked up by a CCD camera.

  The liquid level floating foreign substance inspection apparatus of the present invention is arranged below the container in an inspection apparatus for detecting foreign substances floating in or near the liquid level of the liquid filled in the container whose mouth is sealed with a cap with a pull tab. And an illumination for illuminating the inside of the container from the bottom side of the container, and a CCD camera disposed on the side of the container, the inside of the container is illuminated from the bottom side of the container by the illumination, and the liquid level is passed through the liquid in the container. And a part of the light reaching the liquid level is made incident on a portion where the liquid level is raised at a site where the liquid level and the container inner surface are in contact with each other. The reflected light reflected by the interface is imaged by a CCD camera arranged on the side of the container.

  According to the present invention, when the inside of the container is illuminated from the bottom surface side of the container by illumination arranged below the container, the light incident on the container reaches the liquid surface, and a part of the light reaching the liquid surface is the liquid surface Since the incident light is reflected at the interface between the liquid surface and the gas at the raised portion, and the reflected light is incident on the CCD camera to be photographed. If the image is a bright image and there is a foreign object in this raised area, the foreign object appears as a dark shadow on a bright background. By detecting this dark shadow, the foreign object can be detected. Can do.

  In a preferred aspect of the present invention, a second illumination is arranged above the container, and the pull tab is illuminated by the second illumination.

  According to the present invention, the diffused light from the second illumination illuminates the pull tab that hangs from the outer periphery of the cap. As a result, the pull tab is illuminated brightly. The brightness of the pull tab is adjusted so that the image pickup device of the CCD camera becomes bright, and this bright portion appears white in the image. Since the pull tab portion is a white image portion in this way, the pull tab and the foreign object appearing as a dark shadow can be easily determined by image processing by the image processing apparatus.

  In a preferred aspect of the present invention, a diffusion plate is arranged above the container, light is directly incident on the diffusion plate from the illumination, and the outer peripheral surface of the cap and the pull tab are illuminated by reflected light reflected by the diffusion plate. It is characterized by.

  According to the present invention, a part of the diffused light from the illumination enters the diffuser plate above the container through the outer peripheral side of the container, and the diffuser plate is made of a white diffuser plate and can diffuse the incident light. Therefore, the illumination light from the illumination is diffusely reflected, and the pull tab hanging from the outer peripheral edge of the cap is illuminated by the reflected light. As a result, the pull tab is illuminated brightly. The brightness of the pull tab is adjusted so that the image pickup device of the CCD camera becomes bright, and this bright portion appears white in the image. Since the pull tab portion is a white image portion in this way, the pull tab and the foreign object appearing as a dark shadow can be easily determined by image processing by the image processing apparatus.

In a preferred aspect of the present invention, the foreign matter present at the raised portion is imaged by the CCD camera together with the reflected light reflected at the interface.
In a preferred aspect of the present invention, when the foreign matter is a light-shielding foreign matter, an image portion due to reflected light is bright and an image portion due to the foreign matter is dark in an image obtained by the CCD camera. .
In a preferred aspect of the present invention, when the foreign matter is a transmissive foreign matter, in the image obtained by the CCD camera, the image portion due to the foreign matter is darker due to refraction inside the foreign matter than the image portion due to the reflected light. Or it becomes brighter than the surroundings due to the light collecting effect.
The preferable aspect of this invention hold | maintains the trunk | drum of a container, and conveys a container along the conveyance path | route which exists above the said illumination.

The present invention has the following effects.
(1) According to the present invention, when the inside of the container is illuminated from the bottom surface side of the container by illumination disposed below the container, the light incident on the container is reflected directly or on the inner surface of the container and is condensed on the liquid surface. A part of the light condensed on the liquid surface is incident on the raised portion where the liquid surface and the inner surface of the container are in contact, and this incident light is reflected at the interface between the liquid surface and the gas at the raised portion, and this reflected light. Is incident on the CCD camera, and the raised part becomes a bright image part. If there is a foreign object at this raised part, the foreign object appears as a dark shadow on a bright background. Foreign matter can be detected by determining dark shadows.
(2) There is no need to move a foreign substance or draw a foreign substance into the liquid using a large-scale conveying apparatus such as a rotary type conveying apparatus or a spin conveying apparatus. It is possible to detect a foreign object at a location where the contact is raised.
(3) Light is incident on the pull tab from the illumination (or diffuser), and the brightness of this portion is adjusted so that the image pickup device of the CCD camera becomes bright, so this bright portion is completely white in the image. It will be reflected in the state. Since the pull tab portion is a white image portion in this way, even if the foreign object is behind the pull tab and overlaps the pull tab, if the foreign object is exposed from the pull tab and goes outside, the pull tab is dark. A foreign object reflected as a shadow can be easily discriminated.

FIG. 1 is a front view showing a basic configuration of a liquid level floating particle inspection apparatus according to the present invention. FIG. 2 is a diagram for explaining the operation of the liquid level floating foreign matter inspection apparatus configured as shown in FIG. FIG. 3 is a diagram showing an optical path when light from the bottom surface illumination 5 reaches a place where the liquid surface and the inner surface of the container are raised and the light reflected from the raised place is photographed by the CCD camera. . FIG. 4 is an image taken using the illumination imaging system shown in FIG. FIG. 5 is another image taken using the illumination imaging system shown in FIG. FIG. 6 is a diagram for explaining the operation of the liquid level floating foreign substance inspection apparatus configured as shown in FIG. FIG. 7 is an image taken using the illumination imaging system shown in FIG. FIG. 8 is an image taken using the illumination imaging system shown in FIG. FIG. 9 is a diagram showing a specific configuration of a liquid level floating foreign matter inspection apparatus capable of performing foreign matter inspection while linearly transporting a container, and is a front view of the liquid level floating foreign matter inspection apparatus. FIG. 10 is a diagram illustrating an optical path when light is applied to the container from the side surface of the container.

Embodiments of a liquid surface floating particle inspection method and apparatus according to the present invention will be described below with reference to FIGS. 1 to 9, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.
FIG. 1 is a front view showing a basic configuration of a liquid level floating particle inspection apparatus according to the present invention. As shown in FIG. 1, the container 1 is a colorless and transparent cylindrical container-shaped glass wide-mouth container, and is filled with a liquid L as a beverage such as sake. The mouth of the container 1 is sealed with a cap (lid) 2 made of a metal plate such as aluminum. The cap (lid) 2 is formed with a substantially ring-shaped portion 3 called a pull tab or pull ring for hooking and pulling up a finger to facilitate opening. Hereinafter, this substantially ring-shaped portion is collectively referred to as a pull tab. The pull tab 3 extends downward from the outer peripheral edge of the cap 2 along the outer peripheral surface of the container 1 and extends below the liquid surface Le of the liquid L filled in the container 1. On the back surface of the cap 2, a ring-shaped packing for adhering to the top surface of the mouth of the container 1 for sealing is attached. The cap 2 is made of a metal plate such as aluminum, and a white glossy color coating is applied to the metal plate base on the back surface of the cap. The ring packing is also white.

  Below the container 1, a bottom illumination 5 that illuminates the inside of the container 1 from the container bottom side is disposed. The bottom illumination 5 has a disk shape or a flat plate shape having a larger area than the bottom surface of the container 1 and is composed of diffuse illumination configured by arranging a large number of LEDs. Further, a CCD camera 6 and a side illumination 9 are arranged on the side of the container 1 so as to sandwich the container 1. That is, the CCD camera 6 and the side illumination 9 are arranged at an interval of 180 ° in the circumferential direction.

  On the other hand, an upper illumination 7 for illuminating the container 1 from above is disposed above the container 1. The upper illumination 7 is disposed immediately above the cap 2 and illuminates the pull tab 3 depending from the outer peripheral edge of the cap 2. The upper illumination 7 has a disk shape or a plate shape having an area larger than that of the cap (lid) 2 and is composed of diffused illumination configured by arranging a large number of LEDs. The upper illumination 7 may be replaced with a diffusion plate for irradiating the illumination light from the bottom illumination 5 and illuminating the container 1 with the reflected light. In this case, the diffusing plate 7 is made of, for example, a white diffusing plate, and diffuses the illumination light from the bottom surface illumination 5 to illuminate the pull tab 3 that hangs down from the outer peripheral edge of the cap 2 with the reflected light. Then, a white reflector is disposed on the upper surface of the diffuser plate 7, and even if a small part of the illumination light from the bottom illumination 5 passes through the diffuser plate 7, it is reflected by the white reflector and the light is directed to the container side. You may make it illuminate the container side by returning.

  The optical axis 6x of the CCD camera 6 substantially coincides with the liquid level Le of the liquid L in the container 1, and is configured to take an image of the inside of the container 1 from the side surface of the container. The CCD camera 6 is connected to an image processing device (not shown) that processes images.

Next, the operation of the liquid level floating foreign substance inspection apparatus configured as shown in FIG. 1 will be described with reference to FIGS.
In order to verify the operational effect of the upper illumination (or diffusion plate) 7 disposed above the container 1, the case where the upper illumination 7 is not installed and the case where the upper illumination 7 is installed will be described separately.

1) When the upper illumination (or diffusion plate) 7 is not installed As shown in FIG. 2, the diffused light from the bottom illumination 5 enters the bottom surface 1 a of the container 1, passes through the bottom surface 1 a, and enters the container 1. To do. The light that has entered the container 1 travels through the liquid and reaches the back surface of the cap (lid) 2. Since the back surface of the cap 2 is white and glossy, and can diffusely reflect light, the diffused reflection makes it appear as if the illumination is lit on the back surface of the lid. That is, the liquid surface and the liquid in the container 1 are illuminated brightly by the light from the bottom illumination 5 and the light irregularly reflected on the back surface of the cap 2. The liquid surface suddenly rises at the part where the liquid surface and the container inner surface contact due to the surface tension of the liquid and the adhesion force between the liquid and the container wall surface. 5 is incident and reflected by the arcuate interface (surface of the boundary between the liquid and gas) of the raised portion, and the reflected light is photographed by the CCD camera 6. Therefore, the raised portion becomes a substantially uniformly bright image portion.

  Further, the diffused light from the side illumination 9 passes through the side surface of the container 1 and enters the container 1. The light that has entered the container 1 passes through the air on the liquid surface and the liquid surface with a predetermined refractive index, and exits the container. For this reason, the side illumination 9 also brightly illuminates the portion that was dark only by the bottom illumination 5, that is, the lower side where the liquid level and the inner surface of the container contacted and raised. As described above, by dimming the bottom surface illumination 5 and the side surface illumination 9, it is possible to brighten the liquid surface and the inner surface of the container in contact with each other to the lower liquid portion in the same manner. Therefore, the image processing of the liquid surface and the foreign matter in the vicinity thereof is also facilitated.

FIG. 3 is a diagram showing an optical path when light from the bottom surface illumination 5 reaches a place where the liquid surface and the inner surface of the container are raised and the light reflected from the raised place is photographed by the CCD camera 6. is there.
As shown in FIG. 3, the liquid level suddenly rises at the site where the liquid level and the inner surface of the container are in contact, but the light from the bottom illumination 5 reaches this raised location, and part of the light is arcuate. The reflected light passes through the container 1 and enters the CCD camera 6. That is, the light from the bottom illumination 5 is incident on a portion where the liquid level and the inner surface of the container are raised, and the light reflected by the raised portion is photographed by the CCD camera 6, and the raised portion is displayed on the imaging screen. Brighter image area.

FIG. 4 is an image taken using the illumination imaging system shown in FIG. As shown in FIG. 4, in the image photographed by the CCD camera 6, the raised portion is a bright image portion. Therefore, when there is a foreign matter (for example, a light-shielding foreign matter such as a blackish foreign matter) at the raised portion, the foreign matter appears as a dark shadow on a bright background. FIG. 4 clearly shows a small rectangular dark shadow in a light background. A foreign object can be detected by discriminating this dark shadow by the image processing apparatus.
In the image shown in FIG. 4, the pull tab 3 is also shown as a dark shadow. In the case of FIG. 4, since the image portion of the pull tab is separated from the image portion shown as a rectangular dark shadow, the pull tab and the foreign matter can be discriminated by image processing by the image processing apparatus.

  FIG. 5 is another image taken using the illumination imaging system shown in FIG. As shown in FIG. 5, in the image photographed by the CCD camera 6, the raised portion is a bright image portion. A small rectangular dark shadow appears in the light background, but this rectangular black shadow overlaps the image portion of the pull tab. As described above, when a foreign object enters the back side of the pull tab, the foreign object appears as a dark dark shadow on the image, but the image processing cannot distinguish the foreign object from the pull tab.

2) When the upper illumination (or diffusion plate) 7 is installed As shown in FIG. 6, the diffused light from the bottom illumination 5 enters the bottom surface 1 a of the container 1, passes through the bottom surface 1 a, and enters the container 1. To do. The light that has entered the container 1 travels through the liquid and reaches the back surface of the cap (lid) 2. Since the back surface of the cap 2 is white and glossy, and can diffusely reflect light, the diffused reflection makes it appear as if the illumination is lit on the back surface of the lid. That is, the liquid surface and the liquid in the container 1 are illuminated brightly by the light from the bottom illumination 5 and the light irregularly reflected on the back surface of the cap 2. The liquid surface suddenly rises at the part where the liquid surface and the container inner surface contact due to the surface tension of the liquid and the adhesion force between the liquid and the container wall surface. 5 is incident and reflected by the arcuate interface (surface of the boundary between the liquid and gas) of the raised portion, and the reflected light is photographed by the CCD camera 6. Therefore, the raised portion becomes a substantially uniformly bright image portion. The optical path through which the light from the bottom illumination 5 reaches the CCD camera 6 is as shown in FIG.

  Further, the diffused light from the side illumination 9 passes through the side surface of the container 1 and enters the container 1. The light that has entered the container 1 passes through the air on the liquid surface and the liquid surface with a predetermined refractive index, and exits the container. For this reason, the side illumination 9 also brightly illuminates the portion that was dark only by the bottom illumination 5, that is, the lower side where the liquid level and the inner surface of the container contacted and raised. As described above, by dimming the bottom surface illumination 5 and the side surface illumination 9, it is possible to brighten the liquid surface and the inner surface of the container in contact with each other to the lower liquid portion in the same manner. Therefore, the image processing of the liquid surface and the foreign matter in the vicinity thereof is also facilitated.

  On the other hand, the diffused light from the upper illumination 7 illuminates the pull tab 3 depending from the outer peripheral edge of the cap 2. As a result, the pull tab 3 hanging from the outer peripheral edge of the cap 2 is brightly illuminated. The brightness of the pull tab 3 is adjusted so that the image sensor of the CCD camera becomes brighter. This is done by adjusting the brightness of the bottom illumination 5 below the container 1 and adjusting the brightness of the upper illumination 7. In the case of the diffusion plate 7 instead of the upper illumination, the brightness of the bottom illumination 5 below the container 1 is adjusted, and the desired material and structure of the diffusion plate 7 are selected.

  7 and 8 are images taken using the illumination imaging system shown in FIG. As shown in FIGS. 7 and 8, in the image taken by the CCD camera 6, the raised portion is a bright image portion, and foreign matter (for example, a light-shielding foreign matter such as a blackish foreign matter) exists in the raised portion. When doing so, the foreign object appears as a dark shadow on a light background. On the other hand, light is incident on the pull tab 3 from the upper illumination 7, and the brightness of this portion is dimmed so that the image pickup device of the CCD camera 6 is bright, so this bright portion appears white in the image. It will be in a state to end up. If the pull tab portion becomes a white image portion as described above, the pull tab and the foreign matter appearing as a dark dark shadow can be easily determined by image processing by the image processing apparatus.

  In the image shown in FIG. 7, the image portion of the pull tab is slightly separated from the image portion due to the foreign matter appearing as a rectangular dark shadow. However, in the image shown in FIG. The image part due to the foreign object reflected as a shadow overlaps. 7 and 8, since the pull tab portion is a white image, it is possible to discriminate between the pull tab and a foreign object appearing as a rectangular dark shadow by image processing. In FIG. 8, the foreign matter is behind the pull tab and overlaps the pull tab. However, since the foreign matter is exposed from the pull tab and protrudes to the outside, the pull tab and the foreign matter appearing as a dark shadow can be discriminated.

Next, a liquid surface floating foreign substance inspection apparatus that embodies the basic concept shown in FIG. 1 and can perform foreign substance inspection while linearly conveying the container 1 will be described.
FIG. 9 is a diagram showing a specific configuration of a liquid level floating foreign matter inspection apparatus capable of performing foreign matter inspection while linearly transporting a container, and is a front view of the liquid level floating foreign matter inspection apparatus. As shown in FIG. 9, the liquid surface floating foreign substance inspection apparatus includes a pair of left and right transport apparatuses 10 and 10 that linearly transport the container 1, and the container 1 includes a transport belt 11 of the pair of transport apparatuses 10 and 10. , 11 is conveyed in a direction perpendicular to the paper surface while the body portion is sandwiched between them. The conveyor belts 11 and 11 are respectively wound around a pair of pulleys (not shown) provided before and after in the conveyance direction, and the conveyor belts 11 and 11 sandwich the container 1 by rotating the pulleys. It is designed to run at the same speed.

  A bottom illumination 5 for illuminating the inside of the container 1 from the bottom side of the container is disposed below the conveyance path of the container 1. The bottom illumination 5 has a disk shape or a flat plate shape having a larger area than the bottom surface of the container 1 and is composed of diffuse illumination configured by arranging a large number of LEDs. Further, a CCD camera 6 and a side illumination 9 are arranged on the side of the container 1 so as to sandwich the container 1. That is, the CCD camera 6 and the side illumination 9 are arranged at an interval of 180 ° in the circumferential direction.

  On the other hand, an upper illumination 7 for illuminating the container 1 from above is disposed above the container 1. The upper illumination 7 is disposed immediately above the cap 2. The upper illumination 7 has a disk shape or a plate shape having an area larger than that of the cap (lid) 2 and is composed of diffused illumination configured by arranging a large number of LEDs. The upper illumination 7 may be replaced with a diffusion plate for irradiating the illumination light from the bottom illumination 5 and illuminating the container 1 with the reflected light.

  The optical axis 6x of the CCD camera 6 substantially coincides with the liquid level Le of the liquid L in the container 1, and is configured to take an image of the inside of the container 1 from the side surface of the container. The CCD camera 6 is connected to an image processing device (not shown) that processes images.

  In the liquid level floating foreign matter inspection apparatus configured as shown in FIG. 9, the container 1 filled with the liquid L is positioned above the bottom illumination 5 while being sandwiched and transported by the pair of transport belts 11, 11. pass. While the container 1 passes above the bottom illumination 5, the inside of the container 1 is illuminated and the liquid level Le is photographed by the CCD camera 6. The mechanism for detecting foreign matter floating on the liquid surface in the container 1 and the mechanism for whitening the pull tab 3 are as described in FIG.

The bottom illumination 5 and the top illumination 7 may be visible light such as white light or infrared light.
4 to 8 exemplify the case of imaging a black light-shielding foreign material, but it is also possible to image when there is a transmissive foreign material at a location where the liquid surface and the inner surface of the container are in contact with each other. The transparent foreign matter appears as a dark image portion due to refraction inside the foreign matter, or as a brighter image portion due to the light collecting effect, as compared to an image portion where the raised portion becomes bright.
Furthermore, a color CCD camera may be used depending on the foreign object to be detected. When the foreign matter is light yellow or the like, it is difficult to discriminate due to the difference in contrast, so a color camera is more effective than a monochrome camera. In addition, adjusting the color and brightness of the illumination as appropriate is also effective for providing a contrast between the background and the foreign object.

  Although the embodiment of the present invention has been described so far, the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention may be implemented in various different forms within the scope of the technical idea.

1 container 1a bottom surface 2 cap (lid)
3 Substantially ring-shaped part (pull tab)
5 Bottom illumination 6 CCD camera 6x Optical axis 7 Upper illumination 9 Side illumination 10 Conveying device 11 Conveying belt

Claims (11)

In the inspection method for detecting foreign matter floating on or near the liquid level of the liquid filled in the container whose mouth is sealed with a cap with a pull tab,
Illuminate the inside of the container from the bottom side of the container by illumination arranged below the container, illuminate the liquid level through the liquid in the container,
A part of the light reaching the liquid surface is incident on a portion where the liquid surface is raised at a portion where the liquid surface and the inner surface of the container are in contact, and the incident light is reflected at the interface between the liquid surface and the gas at the raised portion. ,
A liquid surface floating foreign matter inspection method, wherein the reflected light reflected at the interface is imaged by a CCD camera disposed on the side of the container.   The liquid level floating foreign substance inspection method according to claim 1, wherein a second illumination is disposed above the container, and the pull tab is illuminated by the second illumination.   2. The liquid surface floating according to claim 1, wherein a diffusion plate is disposed above the container, light is directly incident on the diffusion plate from the illumination, and the pull tab is illuminated by reflected light reflected by the diffusion plate. Foreign substance inspection method.   4. The liquid level floating foreign matter inspection method according to claim 1, wherein the foreign matter existing at the raised portion is imaged by the CCD camera together with reflected light reflected at the interface. 5.   5. The liquid surface according to claim 4, wherein, when the foreign matter is a light-shielding foreign matter, an image portion due to reflected light is bright and an image portion due to the foreign matter is dark in an image obtained by the CCD camera. Floating foreign substance inspection method.   In the case where the foreign matter is a transmissive foreign matter, in the image obtained by the CCD camera, the image portion due to the foreign matter becomes darker due to refraction inside the foreign matter than the image portion due to the reflected light, or the light collecting effect. The liquid level floating foreign substance inspection method according to claim 4, wherein the liquid surface becomes brighter than the surroundings.   2. The liquid level floating foreign substance inspection method according to claim 1, wherein the container body is held, and the container is transported along a transport path above the illumination. In an inspection apparatus for detecting foreign matter floating on or near the liquid level of a liquid filled in a container whose mouth is sealed with a cap with a pull tab,
Illumination that is arranged below the container and illuminates the inside of the container from the bottom side of the container;
A CCD camera disposed on the side of the container,
Illuminate the inside of the container from the bottom side of the container by the illumination, illuminate the liquid level through the liquid in the container,
A part of the light reaching the liquid surface is incident on a portion where the liquid surface is raised at a portion where the liquid surface and the inner surface of the container are in contact, and the incident light is reflected at the interface between the liquid surface and the gas at the raised portion. ,
A liquid level floating foreign matter inspection apparatus, wherein reflected light reflected at the interface is picked up by a CCD camera disposed on a side of the container.   The second illumination is arranged above the container, and the outer peripheral surface of the cap and the pull tab are illuminated by the second illumination, and the outer peripheral surface of the container immediately below the cap is illuminated. Liquid surface floating foreign substance inspection device.   A diffusion plate is disposed above the container, light is directly incident on the diffusion plate from the illumination, and the outer peripheral surface of the cap and the pull tab are illuminated by reflected light reflected by the diffusion plate, and the outer periphery of the container immediately below the cap The liquid level floating foreign substance inspection apparatus according to claim 8, wherein the surface is illuminated.   9. The liquid level floating foreign substance inspection apparatus according to claim 8, further comprising a transport device that holds the body portion of the container and transports the container along a transport path above the illumination.

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