JP5724070B2 - Liquid surface floating foreign substance inspection method and apparatus - Google Patents

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 A foreign matter inspection system that detects a foreign matter floating near the liquid surface with a camera for a product in which a glass bottle is filled with a liquid such as a beverage is known. For example, in the foreign matter inspection system for glass bottles disclosed in Japanese Patent Application Laid-Open No. 2005-17004 (Patent Document 1), a glass bottle (actual bottle) filled with liquid is formed into an annular shape by a placement part of a rotary inspection table. By transporting at high speed along the path, the liquid surface is moved using centrifugal force and the liquid surface floating foreign material is moved, and the moving foreign material is imaged by the imaging means located on the side of the glass bottle. .

  As disclosed in Patent Document 1, the conventional liquid level floating foreign substance inspection apparatus has a problem that the rotary type inspection table is an essential component and the mechanism becomes extremely complicated. Therefore, the present inventors first illuminate the inside of the container from the bottom surface side of the container with the illumination arranged below the container in Japanese Patent Application Laid-Open No. 2011-69774 (Patent Document 2). Incident light is condensed on the liquid surface, and a part of the light condensed on 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 with each other. An inspection method was proposed in which light is reflected at the interface between the liquid surface and the gas at a location, and the reflected light reflected at the interface is imaged by a CCD camera arranged on the side of the container. According to this inspection method, when the reflected light reflected at the interface between the liquid surface and the gas is photographed with a CCD camera, the portion where the liquid surface rises at the portion where the liquid surface and the container inner surface come into contact becomes a bright image portion. When a foreign object exists at the raised portion, the foreign object appears as a dark shadow on a bright background, and the foreign object can be detected by discriminating this dark shadow.

JP 2005-17004 A JP 2011-69774 A

The present inventors have obtained the following knowledge as a result of repeatedly detecting liquid surface floating foreign substances for various glass bottles filled with liquid using the inspection method proposed in Patent Document 2.
In other words, a colorless and transparent glass bottle or a light colored glass bottle has a high light transmittance, so that light that has passed through the bottom of the glass bottle from the bottom illumination and entered the glass bottle is reflected by the inner surface of the glass bottle. The light is condensed on the liquid surface from various directions. Therefore, the entire liquid surface becomes bright.
On the other hand, dark glass bottles such as brown and black have low light transmittance, so that part of the light that has passed through the bottom of the glass bottle from the bottom illumination and entered the glass bottle is made up of glass bottles. Since it is absorbed by the inner surface, only part of the light reaches the liquid surface. Therefore, only a part of the liquid level becomes bright.

Fig.9 (a) is a figure which shows the image of the liquid level of a glass bottle with high light transmittance, and FIG.9 (b) is a figure which shows the image of the liquid level of a glass bottle with low light transmittance.
As shown in FIG. 9A, in the case of a glass bottle with high light transmittance, the entire liquid surface is a bright image portion. In this state, it is possible to inspect the liquid level foreign matter in the half circumference portion of the entire container on one screen. Accordingly, by disposing the cameras on the front side and the back side of the image in FIG.
As shown in FIG. 9B, in the case of a glass bottle with low light transmittance, only a part near the center of the liquid surface (the range indicated by a double-headed arrow in FIG. 9B) is a bright image portion. In this state, it is difficult to inspect the floating foreign material all around the liquid surface. In order to inspect floating foreign substances all around the liquid surface, it is necessary to image the liquid surface from multiple directions, and it is necessary to arrange a large number of cameras so as to surround the liquid surface.

  The present invention has been made based on the above knowledge, and even when a container with low light transmittance is filled with a liquid, a small number of floating foreign substances around the liquid surface in the container or around the liquid surface are reduced. It is an object of the present invention to provide a liquid level floating foreign object detection method and apparatus that can be detected by a camera.

To achieve the above object, the liquid level floating particle inspection how the present invention can detect foreign matter floating in the vicinity of the liquid surface or liquid level of the liquid filled in the dark of the container to be transported by the transport mechanism In the inspection method to be performed, the step of illuminating the liquid level in the container by illuminating the inside of the container from the bottom side of the container by illumination disposed below the container to be conveyed, and the position of the liquid level in the container to be conveyed Is disposed on the outer peripheral side of the container so as to surround the container, and is provided with a semi-reverse conical mirror surface of two substantially semi-annular cone mirrors facing each other and spaced apart from each other. wherein the step of Ru to reflect light from the liquid surface upwardly, and a step of imaging by the two cameras light reflected disposed above the vessel in the mirror surface of the cone mirror, liquid in the container The horizontal section is temporarily Then, the outer periphery of the container is specified, and when the two points before and after the outer periphery of the specified container and the straight line or the arc matched with the transport direction of the container are specified, The width of the bright image portion in the vicinity of the center of the liquid level in the image obtained by imaging the liquid level of the dark container illuminated from the side of the container from the side so that light is incident on both ends of the two cone mirrors, respectively. Based on this, the size of the gap between the two cone mirrors is set .

According to the present invention, during the transportation of the container, the diffused light from the bottom illumination is incident on the bottom surface of the container, passes through the bottom surface and enters the container, and a part of the light incident on the container is Reflects repeatedly on the inner surface and reaches the liquid level. A part of the light from the liquid surface in the container passes through the neck of the container and then travels radially outward to be reflected by the mirror surfaces of the two semi-circular cone mirrors, and the reflected light travels diagonally upward. And enter the camera. In this case, light from the half circumference part of the liquid level in the container enters one cone mirror, and light from the remaining half circumference part of the liquid level in the container enters the other cone mirror. Even if there is a gap, there is no range of blind spots. Therefore, bright image portions connected in a semi-ring shape are formed on the left and right in the image photographed by the camera. When light-shielding foreign matter exists near the liquid level in the container, the foreign matter appears as a dark shadow on a bright background in the image. A foreign object can be detected by discriminating this dark shadow by the image processing apparatus.
According to the present invention, the light from the half circumference part of the liquid level in the container is incident on one cone mirror, and the light from the remaining half circumference part of the liquid level in the container is incident on the other cone mirror. Even if there is a gap between the two cone mirrors, there is no range of blind spots.

In a preferred aspect of the present invention, the gap between the two cone mirrors is set to a dimension that allows the container to be conveyed to pass from the neck or the neck to the shoulder.
According to the present invention, it is possible to inspect the liquid level foreign matter of the container without blind spots while linearly conveying the container.

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 camera.
In a preferred aspect of the present invention, when the foreign matter is a translucent foreign matter, in the image obtained by the camera, the image portion due to the foreign matter is darker than the image portion due to the reflected light or the surrounding area. It is characterized by further brightening.

The present invention has the following effects.
(1) Even when a container having a dark color such as brown or black and having a low light transmittance is filled with liquid, a floating foreign substance near the liquid level or the liquid level can be detected with a single camera. .
(2) While transporting the container, it is possible to inspect the liquid surface of the container having a low light transmittance without a blind spot.
(3) Since the foreign matter can be detected all around the liquid level without rotating the container, the conveying device is simplified.

FIG. 1 is a schematic longitudinal sectional view showing a basic configuration of a liquid level floating particle inspection apparatus according to the present invention. FIG. 2 is a view taken along the line II-II in FIG. FIG. 3 is a schematic longitudinal sectional view showing a basic configuration of a liquid level floating particle inspection apparatus provided with a split cone mirror according to the present invention. 4 is a view taken along the line IV-IV in FIG. FIG. 5 is a schematic diagram in which the range of the double arrow in FIG. 9B is specified from the image shown in FIG. 9B. FIG. 6 is a part of a configuration diagram in the case where a split cone mirror is arranged on the side of the container, and the arcuate range (thick double-arrow portion) corresponds to the position of the gap between the cone mirrors. FIG. 7 is a schematic longitudinal cross-sectional view showing a liquid level floating foreign substance inspection apparatus according to the present invention having a configuration that allows light from the entire circumference of the liquid level in the container to be incident on the cone mirror. FIG. 8 is a view taken along line VIII-VIII in FIG. Fig.9 (a) is a figure which shows the image of the liquid level of a glass bottle with high light transmittance, and FIG.9 (b) is a figure which shows the image of the liquid level of a glass bottle with low light transmittance.

Hereinafter, embodiments of a liquid surface floating foreign matter inspection method and apparatus according to the present invention will be described with reference to FIGS. 1 to 8, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.
FIG. 1 is a schematic longitudinal sectional view showing a basic configuration of a liquid level floating particle inspection apparatus according to the present invention. FIG. 2 is a view taken along the line II-II in FIG. As shown in FIG. 1, the container 1 is made of a glass bottle having a dark color such as brown or black and having a low light transmittance, and the container 1 is filled with a liquid L such as a beverage. Below the container 1, a bottom illumination 2 for illuminating the inside of the container 1 from the container bottom side is disposed. The bottom surface illumination 2 is a disk-shaped illumination having a slightly larger area than the bottom surface of the container, and is configured by arranging a large number of LEDs. The bottom surface illumination 2 projects diffused light onto the container 1, and the projected diffused light passes through the bottom surface of the container 1 and enters the container 1.

  A CCD camera 3 is disposed above the container 1. That is, the bottom illumination 2 and the CCD camera 3 are arranged so as to sandwich the container 1. The optical axis 3x of the CCD camera 3 substantially coincides with the axis 1x of the container 1. The CCD camera 3 is connected to an image processing device (not shown) that processes an image. Further, a cone mirror 4 is disposed on the outer peripheral side of the container 1 so as to surround the neck 1 n of the container 1. The cone mirror 4 is made of an annular member, and has an inverted conical mirror surface 4m on the inner peripheral side. The inverted conical mirror surface 4m is set such that the radius of the lower end from the center of the inverted conical surface is R1, and the radius of the upper end is R2.

  As shown in FIGS. 1 and 2, the entire circumference of the neck 1 n of the container 1 is surrounded by the mirror surface 4 m of the cone mirror 4. The inverted conical mirror surface 4m is formed to be inclined by a predetermined angle (θ) with respect to the horizontal plane, and the central portion of the mirror surface 4m is roughly the liquid surface Le of the liquid L in the container 1 in the horizontal direction. Match. The inclination angle (θ) is set to approximately 40 ° to 60 °.

Next, the operation of the liquid level floating foreign matter inspection apparatus configured as shown in FIGS. 1 and 2 will be described.
The diffused light from the bottom illumination 2 enters the bottom surface 1a of the container 1, passes through the bottom surface 1a, and enters the container 1. Part of the light incident into the container 1 is repeatedly reflected on the inner surface of the container and reaches the liquid level Le. In the process of reflection, part of the light is absorbed by the inner surface of the container 1. Part of the light from the liquid level Le in the container 1 travels radially outward after passing through the neck 1n of the container 1 and is reflected by the mirror surface 4m of the cone mirror 4, and the reflected light travels obliquely upward. Is incident on the CCD camera 3. In this case, since the light from the liquid surface Le in the container 1 is incident on the entire circumference of the mirror surface 4m having an inverted conical surface, the liquid surface shines in a ring shape on the mirror surface 4m.

When the image is taken from one direction with a CCD camera arranged on the side of the liquid level Le in the container 1 without using the cone mirror 4, as shown in FIG. 9B, a part near the center of the liquid level. Only a bright image portion (the range indicated by a double-headed arrow in FIG. 9B) becomes a bright image portion. However, as shown in FIGS. 1 and 2, by using the cone mirror 4, the liquid level Le in the container 1 is changed to the normal direction of the outer periphery of the container on the horizontal plane of the liquid level Le (hereinafter simply referred to as the normal direction). Therefore, the imaging system observes the entire circumference of the container, and the liquid surface shines in a ring shape on the mirror surface 4m. That is, the mirror surface 4m shines with a bright range indicated by a double-headed arrow shown in FIG. 9B connected in a ring shape in the circumferential direction. Therefore, a bright image portion connected in a ring shape is formed in the image photographed by the CCD camera 3.
When light-shielding foreign matter exists near the liquid surface in the container 1, the foreign matter appears as a dark shadow on a bright background in the image. A foreign object can be detected by discriminating this dark shadow by the image processing apparatus.

  1 and 2, the cone mirror 4 surrounds the entire circumference of the upper portion of the neck 1n and the shoulder 1s of the container 1, so that the inspection is performed while the container 1 is being transported. I can't. In recent years, from the viewpoint of food hygiene management, for glass containers filled with beverages such as sake and nutritional drinks, an inspection device that can automatically detect foreign substances mixed in beverages without the visual observation of workers. Demand is increasing. In this case, the inspection apparatus is required to inspect the foreign matter floating on the liquid level in the container while the container is being transported at a high speed (for example, 1000 BPM (lines / minute) or more). Next, a liquid surface floating foreign substance inspection apparatus capable of performing inspection during container transportation in this way will be described.

Based on the liquid level floating foreign substance inspection apparatus shown in FIGS. 1 and 2, the present inventors cut the annular cone mirror 4 to carry the container and cut the neck 1n of the container 1 by the split cone mirror. In addition, an attempt was made to form a gap through which the upper part of the shoulder 1s can pass.
3 and FIG. 4, the cone mirror 4 shown in FIG. 1 and FIG. 2 is cut to produce a split cone mirror 4A, 4B, and the container is linearly conveyed by using the split cone mirror 4A, 4B. It is a figure which shows the example which comprised the test | inspection apparatus which can test | inspect a liquid level floating foreign material. FIG. 3 is a schematic longitudinal sectional view showing the basic configuration of the liquid surface floating foreign substance inspection apparatus, and FIG. 4 is a view taken along the line IV-IV in FIG.

  As shown in FIG. 3, the liquid surface floating foreign substance inspection apparatus includes a pair of left and right transport belts 11, 11 for linearly transporting the container 1, and the container 1 is narrowed by the pair of transport belts 11, 11. It is conveyed in a direction perpendicular to the paper surface while being held. 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 glass bottle 1 by rotating the pulleys. It is designed to run at the same speed in the state.

  As shown in FIGS. 3 and 4, the split cone mirrors 4 </ b> A and 4 </ b> B are arranged on the outer peripheral side of the container 1 so as to surround the neck 1 n of the container 1 from the left and right. Each of the cone mirrors 4A and 4B is made of a substantially semi-annular member, and includes mirror surfaces 4mA and 4mB having a semi-inverted conical shape on the inner peripheral side. Between the two cone mirrors 4A and 4B, gaps d1 and d1 are formed so that the container 1 can be linearly conveyed in the A direction by the conveyor belts 11 and 11. The gap d1 is set in a range in which the neck 1n and the upper portion of the shoulder 1s of the container 1 can pass with a margin. The two cone mirrors 4A and 4B are formed such that gaps d1 and d1 are formed from the cone mirror 4 shown in FIGS. That is, the mirror surfaces 4mA and 4mB of the cone mirrors 4A and 4B are set such that the radius of the lower end from the center of the half inverted cone surface is R1, and the radius of the upper end is R2. The gaps d1 and d1 are formed between the cone mirrors 4A and 4B. The semi-inverted conical mirror surfaces 4mA and 4mB are formed to be inclined at a predetermined angle (θ) with respect to the horizontal plane, and the center of the mirror surfaces 4mA and 4mB is the liquid surface in the container 1 in the horizontal direction. It is approximately the same as Le. The inclination angle (θ) is set to approximately 40 ° to 60 °. The bottom illumination 2 is arranged below the container 1 as in the inspection apparatus shown in FIG.

Next, the operation of the liquid level floating foreign substance inspection apparatus configured as shown in FIGS. 3 and 4 will be described.
During conveyance of the container 1, the diffused light from the bottom illumination 2 enters the bottom surface 1 a of the container 1, passes through the bottom surface 1 a, and enters the container 1. Part of the light incident into the container 1 is repeatedly reflected on the inner surface of the container and reaches the liquid level Le. In the process of reflection, part of the light is absorbed by the inner surface of the container 1. Part of the light from the liquid surface Le in the container 1 passes through the neck 1n of the container 1 and then travels radially outward to be reflected by the mirror surfaces 4mA and 4mB of the split cone mirrors 4A and 4B. Advances obliquely upward and enters the CCD camera 3. In this case, the light from the liquid surface Le in the container 1 is incident on the mirror surfaces 4mA and 4mB of the half inverted conical surfaces of the split cone mirrors 4A and 4B, but there is a gap between the cone mirrors 4A and 4B. Since d1 and d1 are formed and there is a part without a mirror, ranges De and De that are blind spots are formed. Therefore, when there is a floating foreign object in the range De that becomes the blind spot, the foreign object is not reflected and cannot be detected.

  In order to eliminate the above-described ranges De and De, which are the blind spots, the present inventors have taken an image when the liquid level Le is photographed from one direction with a CCD camera disposed on the side of the container 1 without using a cone mirror. Paying attention to (see FIG. 9B), the following analysis was performed. That is, when the liquid level Le in the container 1 is photographed from one direction with a CCD camera, as shown in FIG. 9B, a portion near the center of the liquid level (the range indicated by a double-headed arrow in FIG. 9B) is bright. It becomes an image part. The CCD camera is arranged in front of the image in FIG. In this case, paying attention to the middle point in the range of the double arrow in FIG. 9B, the bright point of the middle point is the container of the bright light incident on the CCD camera (located on the near side of the container) from the container. This corresponds to light in the outer peripheral normal direction (referred to as a complete normal direction). In FIG. 9B, the range of the double arrow has a predetermined width from the middle point to the left and right, so that light from a position shifted to the left and right from the complete normal direction also enters the CCD camera to form a bright image portion. You can see that

Next, the result of examination from the image shown in FIG. 9B regarding which range on the outer periphery of the container the range of the double-headed arrow in FIG. 9B corresponds will be described. FIG. 5 is a schematic diagram in which the range of the double arrow in FIG. 9B is specified from the image shown in FIG. 9B. As shown in FIG. 5, the outer periphery OC of the container 1 is drawn by taking a horizontal section at the liquid level of the container from the image shown in FIG. 9B, and the double-headed arrow in FIG. 9B is drawn on the outer periphery OC of the container. an arc-shaped range a _R equal to the range. The arcuate range A _R may also be replaced is called the angular range around the axis 1x of the container 1.

In FIG. 6, the split cone mirrors 4A and 4B are arranged on the side of the container 1, and the arcuate area A _R (the thick double arrow portion) is made to correspond to the position of the gap between the cone mirrors 4A and 4B. It is a part of configuration diagram in the case. In FIG. 6, light from the half circumference portion of the liquid level Le in the container 1 enters one cone mirror 4 </ b> A, and light from the remaining half circumference portion of the liquid level Le in the container 1 enters the other cone mirror 4 </ b> B. Then, even if there is a gap between the cone mirrors 4A and 4B, there is no range of blind spots. In this case, as shown in FIG. 6, the arc-shaped range _(1/2) obtained by dividing the arcuate range _{A R} into two left and right A R, assuming (1/2) _{A R,} the left cone mirror 4A the light from the left arcuate range of half (1/2) _{a R} arranged cone mirror 4A to enter the arcuate extent of the right half on the right side of the cone mirror 4B (1/2) from _{a R} by arranging the cone mirror 4B such that the light incident in the range of clockwise from the left end e _L of the arcuate range a _R is incident on a cone mirror 4A, anti the right end e _R of the arcuate range a _R It is clear that the clockwise range is incident on the cone mirror 4B, and light from the entire circumference of the liquid surface Le in the container 1 can be incident on the cone mirrors 4A and 4B.

Next, referring to FIG. 7 and FIG. 8, an inspection apparatus having a configuration capable of causing light from the entire circumference of the liquid level Le in the container 1 to enter the cone mirrors 4A and 4B as shown in FIG. explain.
FIG. 7 is a schematic longitudinal sectional view showing a liquid level floating foreign substance inspection apparatus according to the present invention having a configuration that allows light from the entire circumference of the liquid level Le in the container 1 to enter the cone mirrors 4A and 4B. FIG. 8 is a view taken along line VIII-VIII in FIG.

7 and FIG. 8, the cone mirrors 4A and 4B shown in FIGS. 3 and 4 are brought close to each other as indicated by arrows B and B, and the gaps d2 and d2 between the two cone mirrors 4A and 4B. Is made smaller. That is, d2> d1. This gap d2 is set to the minimum of a range in which the upper part of the neck 1n and the shoulder 1s of the container 1 can pass without any trouble. Thus, the two cone mirror 4A, by reducing the gap d2, d2 between 4B, assuming the arcuate range A _R shown in FIG. 6, the arc-shaped range of the left half on the left side of the cone mirror 4A (1/2) applying light from _{a R,} arcuate range of the right half on the right side of the cone mirror 4B (1/2) can be incident light from _{a R.}

FIG. 8 shows that light from a position shifted to the left and right from the complete normal direction among the light from the liquid level Le in the container 1 is incident on both ends of the cone mirrors 4A and 4B. In this case, arcuate range _{A R} midpoint of (6) (1/2) light from _{A R} is at least two cone mirror 4A, to be incident on the end portion of 4B, cone mirror 4A, between 4B It is necessary to set the gaps d2 and d2. Of course, as shown in FIG. 8, the midpoint (1/2) incident from the right side of the position from _{A R} to the left of the cone mirror 4A, the middle point (1/2) from _{A R} from the position of the left right The gaps d2 and d2 may be set so as to enter the cone mirror 4B.

The configurations of the bottom illumination 2, the CCD camera 3, and the conveyor belt 11 in the inspection apparatus shown in FIGS. 7 and 8 are the same as those in the inspection apparatus shown in FIGS.
The split cone mirrors 4A and 4B may have an inner diameter that can surround the neck 1n and the shoulder 1s of the container 1, but when the inner diameter is small, the two cone mirrors 4A and 4B are used. Even if they are brought close to each other, there is a disadvantage that a dead angle range is formed (remains). In the case of a large diameter, there is no influence on inspection, but it is disadvantageous in terms of cost and installation space. For example, if the diameter of the neck 1n of the container 1 is approximately 40 mm, the inner diameters of the cone mirrors 4A and 4B (before the cone mirrors 4A and 4B are brought closer) are preferably 200 mm to 250 mm.

According to the inspection apparatus shown in FIGS. 7 and 8, assuming the arcuate range A _R shown in FIG. 6, the light from the arc-shaped range (1/2) A _R of the left half on the left side of the cone mirror 4A is incident, arcuate range of the right half on the right side of the cone mirror 4B (1/2) can be incident light from a _R. Range clockwise from the left end e _L of the arcuate range A _R is incident on a cone mirror 4A, the arcuate range A counter-clockwise extent than the right edge e _R of _R is is clear that entering the cone mirror 4B Yes, light from the entire circumference of the liquid level Le in the container 1 can be incident on the cone mirrors 4A and 4B. Therefore, bright images connected in a semi-ring shape are formed on the left and right in the image photographed by the CCD camera 3. When light-shielding foreign matter exists near the liquid surface in the container 1, the foreign matter appears as a dark shadow on a bright background in the image. A foreign object can be detected by discriminating this dark shadow by the image processing apparatus.

  In the inspection apparatus shown in FIGS. 7 and 8, the range of the dead angle is eliminated by bringing the two substantially semi-annular cone mirrors 4A and 4B closer to each other, but the circle shown in FIGS. Cone mirrors 4A and 4B in which portions corresponding to the gaps d1 and d1 are deleted from the annular cone mirror 4 may be used.

In the above-described embodiment, the case where the light-shielding foreign material is imaged is illustrated, but the image can also be captured when there is a light-transmitting foreign material near or at the liquid surface. In this case, the translucent foreign matter appears as a darker image portion due to refraction inside the foreign matter or as a brighter image portion due to the light condensing effect, compared to the image portion where the liquid level becomes brighter.
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.
Moreover, although the case where it conveys linearly by a pair of conveyance belt as a conveyance mechanism which conveys a container was illustrated, the conveyance mechanism may be a star wheel which conveys a container along a circular track.

  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.

DESCRIPTION OF SYMBOLS 1 Container 1a Bottom 1n Neck 1s Shoulder 2 Bottom illumination 3 CCD camera 4, 4A, AB Cone mirror 4m, 4mA, 4mB Mirror surface 11 Conveyance belt d1, d2 Gap

Claims (4)

In the inspection method for detecting foreign matter floating on or near the liquid surface of the liquid filled in the dark color container transported by the transport mechanism,
Illuminating the liquid level in the container by illuminating the inside of the container from the bottom side of the container by illumination arranged below the container to be transported;
Semi-inverted cones of two substantially semi-circular cone mirrors arranged on the outer peripheral side of the container so as to surround the position of the liquid level in the container to be conveyed, and facing each other and spaced apart from each other A step of reflecting light from the liquid surface in the container upward by a planar mirror surface;
Imaging the reflected light reflected by the mirror surfaces of the two cone mirrors with a camera disposed above the container,
Two points before and after the outer periphery of the container is specified by virtually imagining a horizontal cross section at the position of the liquid level in the container, and the specified outer periphery of the container and a straight line or an arc matched with the transport direction of the container The liquid level of the dark container illuminated from the bottom side of the container was imaged from the side so that the light from the two front and rear points was incident on both ends of the two cone mirrors. A liquid level floating foreign matter inspection method, wherein a dimension of a gap between the two cone mirrors is set based on a width of a bright image portion in the vicinity of a liquid level center in an image.   2. The liquid floating foreign material inspection method according to claim 1, wherein the gap between the two cone mirrors is set to a size that allows a neck portion or a neck portion to a shoulder portion of the container to be conveyed to pass through.   3. The liquid according to claim 1, 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 camera. Surface floating foreign substance inspection method.   When the foreign matter is a translucent foreign matter, in the image obtained by the camera, the image portion due to the foreign matter is darker or brighter than the surroundings as compared with the image portion due to the reflected light. The liquid level floating foreign substance inspection method according to claim 1 or 2.

Images