JP7229092B2 - Foreign matter inspection device and glass container manufacturing method using the same - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foreign matter inspection device for inspecting whether or not foreign matter is mixed in the skirt bottom of a glass container, and a glass container manufacturing method using the same.

Conventionally used foreign matter inspection apparatuses of this type include, for example, the configuration disclosed in Patent Document 1 below. That is, in a conventional foreign matter inspection apparatus, a light source and a camera are arranged so as to sandwich the glass container, and the heel of the glass container is imaged by the camera while the light source is irradiating the glass container with light. there is Then, in the image captured by the camera, a portion that appears darker than the background is determined as a foreign object.

JP-A-11-166906

In the conventional foreign matter inspection apparatus as described above, foreign matter of a certain size, for example, a diameter of 0.8 mm, can be found, but minute foreign matter smaller than that size cannot be found and may be passed through. . The glass container may be damaged due to minute foreign matter remaining on the inner surface of the skirt bottom portion of the glass container. In order to find minute foreign matter, it is necessary to image the inside of the skirt bottom at a high magnification and obtain an image with a shallow depth of field in which only the inside of the skirt bottom is focused. Although it may be possible to obtain such an image using an expensive imaging lens, the equipment cost increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and one of its objects is to provide a foreign matter inspection device and a glass container manufacturing method using the same, which can more reliably detect minute foreign matter. That is.

A contaminant inspection apparatus according to the present invention comprises a light source for irradiating a glass container with light, a camera for capturing an image of the hem and bottom of the glass container, and based on the image captured by the camera, it is determined whether or not foreign matter is mixed in the hem and bottom. The camera has a camera body, a reverse ring attached to the camera body, and an imaging lens attached to the camera body while being turned upside down via the reverse ring.

Further, a foreign matter inspection apparatus according to the present invention comprises a light source for irradiating a glass container with light, a camera for imaging the bottom of the glass container, and whether foreign matter is mixed in the bottom based on the image captured by the camera. the image includes two-dimensional pixel data having an X-axis and a Y-axis, the image including a dark portion located at one end of the X-axis and corresponding to the bottom of the glass container. and a bright portion located on the other end side of the X-axis and corresponding to the skirt of the glass container. The determination device demarcates the detection area line by connecting the X-axis coordinates at which the dark portion is detected for the first time when the dark portion is detected from the other end side to the one end side of the X-axis in the Y-axis direction. an area line demarcation unit, a deviation amount calculation unit that calculates the amount of deviation of the X-axis coordinates of the detection area line along the Y-axis, and a scan of the deviation amount of the X-axis coordinates from one end of the Y-axis toward the other end. , a peculiar area detection unit that detects a peculiar area in which the detection area line is discontinuous due to foreign matter; A detection area line correction unit that corrects the detection area line using the X-axis coordinates of the line, and a foreign matter that detects a dot-like dark part corresponding to the foreign matter between the corrected detection area line and the other end of the X-axis. and a detection unit.

A method of manufacturing a glass container according to the present invention includes a step of inspecting whether or not foreign matter is mixed in the skirt bottom portion of the glass container using the foreign matter inspection apparatus described above.

According to the foreign matter inspection apparatus of the present invention and the glass container manufacturing method using the same, since the imaging lens is attached to the camera body while being turned upside down through the reverse ring, even if an expensive imaging lens is not used, fine particles can be detected. It is possible to obtain an image suitable for finding a foreign object. As a result, minute foreign matter can be found more reliably while suppressing apparatus costs. Further, in the foreign matter inspection apparatus and the glass container manufacturing method using the foreign matter inspection apparatus of the present invention, the detection area line is corrected when the peculiar area is detected, and then the dot-like dark portion corresponding to the foreign matter is detected. can be found more reliably.

1 is a front view showing a glass container to be inspected by a foreign substance inspection apparatus according to an embodiment of the present invention; FIG. FIG. 2 is a cross-sectional view of the hem bottom portion of FIG. 1; 1 is a configuration diagram showing a foreign matter inspection device according to an embodiment of the present invention; FIG. FIG. 4 is an explanatory diagram showing an example of an image of the skirt bottom captured by the camera in FIG. 3 ; 4 is a block diagram showing the configuration of the determination device of FIG. 3; FIG. 6 is an explanatory diagram showing image processing by the determination device of FIG. 5; FIG. It is a flow chart which shows a glass container manufacturing method by an embodiment of the invention.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated with reference to drawings. The present invention is not limited to each embodiment, and can be embodied by modifying the constituent elements without departing from the scope of the invention. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in each embodiment. For example, some components may be deleted from all the components shown in the embodiments. Furthermore, components of different embodiments may be combined as appropriate.

FIG. 1 is a front view showing a glass container 1 to be inspected by a foreign matter inspection apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the hem bottom portion 13 of FIG. The glass container 1 is a container made of transparent or translucent glass. The glass may be colorless transparent glass, or may be colored glass. In this embodiment, a glass container 1 is described as a bottle filled with a beverage. The beverage can be a carbonated beverage.

As shown in FIG. 1 , the glass container 1 is provided with a mouth portion 10 , a shoulder portion 11 , a body portion 12 and a skirt portion 13 .

The mouth portion 10 is a cylindrical portion having an opening that communicates the inside and outside of the glass container 1 , and is provided in the upper portion of the glass container 1 . The shoulder portion 11 is a portion that connects the lower end of the mouth portion 10 and the upper end of the body portion 12 . The inner diameter of the shoulder portion 11 gradually increases from the mouth portion 10 toward the body portion 12 . A pattern 11a is provided on the outer surface of the shoulder portion 11 of the present embodiment. In FIG. 1, the existence of the pattern 11a is indicated by shading. The specific shape of the pattern 11a is arbitrary. The pattern 11 a may not be provided on the outer surface of the shoulder portion 11 . The trunk portion 12 is a tubular portion that connects the lower end of the shoulder portion 11 and the upper end of the hem bottom portion 13 . The inner diameter of the body portion 12 of this embodiment is uniform in the height direction of the glass container 1 .

The hem bottom portion 13 is a portion provided at the lower portion of the body portion 12 . The hem bottom portion 13 includes a hem portion 130 connected to the lower end of the body portion 12 and a bottom portion 131 provided below the hem portion 130 . The skirt portion 130 is a tubular portion similar to the body portion 12 . The bottom part 131 is a part that constitutes the bottom of the glass container 1 . The central portion of the bottom portion 131 of this embodiment is raised toward the inside of the glass container 1 . The outer peripheral surface of the bottom portion 131 is curved. The surface of the connecting portion between the skirt portion 130 and the bottom portion 131 inside the glass container 1 is curved. A knurling may be formed on the lower surface of the bottom part 131 .

A ring mark 132 is formed on the outer peripheral surface of the skirt portion 130 of the present embodiment. As shown in FIG. 2, the ring mark 132 of this embodiment is composed of a pair of grooves 132a and a peak 132b between the grooves 132a. The outer surface of each groove 132a and peak 132b can be formed by an arcuate surface with a radius of curvature of about 3 mm. The distance between the center of the upper groove portion 132a and the bottom surface of the glass container 1 can be about 13 mm. The center of the groove portion 132a can be understood as the deepest position of the depression that constitutes the groove portion 132a. The center-to-center distance of each groove 132a may be on the order of 4 mm. Although not shown, a fine step called a baffle mark may be formed between the skirt portion 130 and the bottom portion 131 .

A foreign substance 2 may be mixed into the inside of the skirt bottom portion 13 when the glass container 1 is manufactured. The foreign matter 2 may be substances other than frit or air bubbles. Substances that constitute the foreign object 2 may be, for example, fine grains of stone, pottery, porcelain, metal, heat-resistant glass, or the like. The substance that constitutes the foreign matter 2 may be embedded in the wall surface of the skirt bottom portion 13 or attached to the wall surface of the skirt bottom portion 13 . The air bubbles forming the foreign matter 2 may be buried in the wall surface of the skirt bottom portion 13 or may form a dent in the wall surface. The foreign matter 2 may be, for example, a minute foreign matter of 0.8 mm or less. Before shipping a glass container 1 or filling a glass container 1 with a beverage, it is necessary to find a glass container 1 with a foreign object 2 remaining on the skirt bottom 13 .

Next, FIG. 3 is a configuration diagram showing the foreign matter inspection apparatus 3 according to the embodiment of the present invention. The foreign matter inspection device 3 shown in FIG. 3 is a device for inspecting whether or not foreign matter 2 is mixed in the hem bottom portion 13 of the glass container 1 . As shown in FIG. 3, the foreign matter inspection apparatus 3 of this embodiment has a base 30, a rotary drive device 31, a light source 32, a camera 33 and a determination device .

The base 30 is a stand on which the glass container 1 is placed. Although only one glass container 1 is shown in FIG. 3 , a plurality of glass containers 1 may be placed on the base 30 . A plurality of glass containers 1 placed on the base 30 are conveyed so as to pass in front of the camera 33 in order. When the glass container 1 to be inspected is positioned in front of the camera 33, the transportation of the glass container 1 is temporarily stopped.

The rotation drive device 31 is a device for rotating the glass container 1 in front of the camera 33 . The glass container 1 is rotated around the central axis 1a of the glass container 1 . The rotary drive device 31 of this embodiment has a drive shaft 310 and a rotary plate 311 . The drive shaft 310 is rotationally driven by the power of a motor (not shown). The rotating plate 311 is attached to the upper portion of the drive shaft 310 and is rotatable together with the drive shaft 310 . The outer peripheral surface of the rotating plate 311 is in contact with the outer surface of the body portion 12 of the glass container 1 , and the glass container 1 is rotated according to the rotation of the rotating plate 311 .

The light source 32 is a device for irradiating the glass container 1 with light. The light source 32 of this embodiment is arranged on the side of the glass container 1 . Although not shown, the light source 32 has a plurality of LED light emitting elements and a diffusion plate arranged in front of the plurality of LED light emitting elements. By emitting the light, it can function as a surface light source. The wavelength of the light from the light source 32 is arbitrary, but when the glass container 1 is made of colored glass, a wavelength with high transmittance to the glass container 1 is preferable. When the glass container 1 is made of brown colored glass, the light from the light source 32 can be red.

The light source 32 is preferably a high-intensity light source that irradiates the glass container 1 with an illuminance of 1700 lx or more when the glass container 1 is a transparent bottle or a colored bottle. By irradiating the glass container 1 with light at an illuminance of 1700 lx or more, the shadow of the disturbance element such as the pattern 11a or the ring mark 132 can be more reliably eliminated in the image of the hem bottom 13 of the glass container 1 captured by the camera 33. Or you can make it thinner. By more reliably erasing or thinning the shadow of the disturbance element, it is possible to improve the detection accuracy of the foreign object 2 based on the image.

When the light control film 320 described later is attached to the light source 32 , the illuminance of the light source 32 described above means the illuminance of light emitted from the light control film 320 . For example, when the light control film 320 allows only about 1/5 of the light from the light source 32 to pass through, the illuminance of the light source 32 itself is 8500 (=1700×5) lx or more when the glass container 1 is a transparent bottle or a colored bottle. Preferably.

A light control film 320 is attached to the light source 32 of this embodiment to limit the diffusion of light from the light source 32 . The light control film 320 is a film provided with a plurality of louvers extending parallel to each other. The louvers of the light control film 320 of this embodiment extend vertically. Light control film 320 directs light from light source 32 toward glass container 1 positioned in front of camera 33 . The light control film 320 limits the irradiation of light around the glass container 1 . By limiting the diffusion of light with the light control film 320, the influence of the light on the surroundings of the foreign matter inspection apparatus 3 can be suppressed. Light control film 320 is particularly useful when using the high intensity light sources described above as light source 32 .

The height of the light source 32 in this embodiment is higher than the height of the glass container 1, and the light from above the light source 32 enters the glass container 1 obliquely from above. It is preferable that the light source 32 illuminates the ring mark 132 at an angle that is an angle obtained by adding an angle θ2 of 12° or more and 22° or less to the elevation angle θ1 of the optical axis 33a of the camera 33 with respect to the horizontal. Ring mark 132 tends to refract light from light source 32 . If the angle of incidence of light on ring mark 132 is small, the shadow of ring mark 132 may appear in the image of camera 33 . By making the light incident on the ring mark 132 at an angle obtained by adding an angle θ2 of 12° or more to the elevation angle θ1, the possibility that the shadow of the ring mark 132 appears in the image of the camera 33 can be reduced. Even if the light is made incident on the ring mark 132 at an angle obtained by adding an angle exceeding 22° to the elevation angle θ1, the effect of the light to reduce the shadow of the ring mark 132 is reduced.

The camera 33 is a device for capturing an image of the hem bottom portion 13 of the glass container 1 . The camera 33 of this embodiment has a camera body 330 , a reverse ring 331 and an imaging lens 332 .

The camera main body 330 has an imaging device such as a CCD, for example. The camera body 330 can be a line sensor camera in which imaging elements are linearly arranged. As the camera body 330 continues to image the glass container 1 rotated in front of the camera 33 by the rotation driving device 31 , an image of the hem bottom 13 can be obtained over the entire circumference of the glass container 1 .

A reverse ring 331 is a device interposed between the camera body 330 and the imaging lens 332 . By interposing the reverse ring 331 between the camera body 330 and the imaging lens 332 , the imaging lens 332 can be attached to the camera body 330 by turning it upside down. In other words, the imaging lens 332 is attached to the camera body 330 with the original front lens facing the camera body 330 and the original rear lens facing the glass container 1 .

By attaching the imaging lens 332 to the camera main body 330 by flipping it upside down, it is possible to take an image at a larger magnification than the original magnification of the imaging lens 332 . As a result, the minute foreign matter 2 can be imaged in a large size, and the detection accuracy of the foreign matter 2 can be improved. In addition, by mounting the imaging lens 332 on the camera body 330 with the front and back turned upside down, the depth of field of the camera 33 can be made extremely shallow to about several millimeters. As a result, it is possible to image minute foreign matter 2 clearly while blurring disturbance elements on the outer surface of skirt bottom portion 13 such as ring mark 132 , thereby improving detection accuracy of foreign matter 2 .

The camera 33 of the present embodiment is arranged so as to capture an image of the skirt bottom portion 13 from obliquely below. The elevation angle θ1 of the optical axis 33a of the camera 33 (the inclination angle of the optical axis 33a with respect to the horizontal) is preferably 33° or more and 43° or less. When the elevation angle θ1 is less than 33°, the imaging surface of the camera 33 approaches the vertical, and a clear image can only be obtained in a limited area in the depth direction. put away. On the other hand, when the elevation angle θ1 exceeds 43°, the imaging surface of the camera 33 becomes nearly horizontal, and a clear image can only be obtained in a limited area in the height direction, so the foreign object 2 on the skirt 130 side is overlooked. Fear increases. When the elevation angle θ1 is 33° or more and 43° or less, the foreign matter 2 on the bottom portion 131 side and the skirt portion 130 side can be imaged in a well-balanced manner, and the detection accuracy of the foreign matter 2 can be improved. The elevation angle θ1 is more preferably 35° or more and 41° or less, and even more preferably 38°. It should be noted that the optical axis 33a of the camera 33 is a straight line orthogonal to the imaging element of the camera body 330 and can be understood as a straight line passing through the center of the imaging element. When the camera body 330 is a line sensor camera, the center of the imaging element can be understood as the position of the center in the extending direction of the imaging element.

The depth of field of the camera 33 is preferably 1.5 mm or more and 5.0 mm or less. If the depth of field is less than 1.5 mm, focusing may become difficult. On the other hand, when the depth of field exceeds 5.0 mm, not only the inside of the skirt bottom portion 13 where the foreign matter 2 may exist, but also the outer surface of the skirt bottom portion 13 is clearly imaged, and disturbance such as the ring mark 132 is captured. There is a possibility that the detection accuracy of the foreign object 2 may be lowered depending on the factors. When the depth of field is 1.5 mm or more and 5.0 mm or less, it is possible to improve the detection accuracy of the foreign object 2 by suppressing the influence of disturbance factors while ensuring ease of focusing. The depth of field is more preferably 2.0 mm or more and 4.5 mm or less, further preferably 3.0 mm or more and 4.0 mm or less, and even more preferably 3.8 mm.

Note that the shorter the focal length of the imaging lens 332, the higher the imaging magnification and the shallower the depth of field.

One or more close-up rings may also be interposed between the camera body 330 and the reverse ring 331 or between the reverse ring 331 and the imaging lens 332 . Imaging magnification can be improved by interposing the close-up ring. When a close-up ring is interposed, the depth of field tends to be shallow.

The determination device 34 is composed of, for example, a computer or a dedicated circuit that performs arithmetic processing based on a program, and is connected to the camera 33 . The determination device 34 determines whether or not the foreign matter 2 is mixed in the skirt bottom portion 13 based on the image captured by the camera 33 .

Next, FIG. 4 is an explanatory diagram showing an example of an image of the hem bottom portion 13 captured by the camera 33 of FIG. As shown in FIG. 4, the image captured by camera 33 includes two-dimensional pixel data having an X-axis and a Y-axis. The X-axis corresponds to the height direction of the glass container 1 and the Y-axis corresponds to the circumferential direction of the glass container 1 . The image includes dark portions 40 and bright portions 41 . The dark portion 40 is a portion corresponding to the bottom portion 131 of the glass container 1 and is located on one end side of the X axis (left side in the figure). The outline of the dark area 40, as an example shown in FIG. 4, is generally composed of continuous curves. The dark portion 40 also includes a pair of spikes 40a corresponding to the baffle marks between the skirt portion 130 and the bottom portion 131. FIG. The spike portion 40a is a thorn-like portion protruding from a continuous curve and has a straight contour that is inclined with respect to both the X-axis and the Y-axis. The bright portion 41 is a portion corresponding to the bottom portion 130 of the glass container 1 and is located on the other end side (right side in the figure) of the X-axis. The foreign matter 2 appears as a dot-like dark portion in the bright portion 41 corresponding to the bottom portion 130 of the glass container 1 .

Next, FIG. 5 is a block diagram showing the configuration of the determination device 34 of FIG. 3, and FIG. 6 is an explanatory diagram showing image processing by the determination device 34 of FIG. As shown in FIG. 5, the determination device 34 of the present embodiment includes a bright contour line demarcation unit 340, an offset unit 341, a detection area line demarcation unit 342, a deviation amount calculation unit 343, a unique area detection unit 344, a detection area It has a line corrector 345 and a foreign object detector 346 .

The bright-portion outline defining unit 340 connects the X-axis coordinates at which the bright portion 41 is detected for the first time when the bright portion 41 is detected from one end of the image to the other end on the X-axis, and plots the coordinates as shown in FIG. A bright outline 5 indicated by a dashed line is defined in (a). A white arrow shown in the dark portion 40 in FIG. 6A indicates how the bright portion 41 is detected from one end of the X-axis toward the other end.

As shown in FIG. 6B, the offset section 341 offsets the bright contour line 5 determined by the bright contour defining section 340 to the other end side of the X axis. The offset amount of the bright contour line 5 is set larger than the width of the spike portion 40a along the X axis so that the bright contour line 5 is separated from the spike portion 40a.

The detection area line defining unit 342 defines the detection area line 6 by connecting the X-axis coordinates at which the dark portion 40 is detected for the first time when the dark portion 40 is detected from the other end side to the one end side of the X-axis in the Y-axis direction. do. At the location where the spike 40a and the foreign object 2 are located, the detection area line 6 is defined along the spike 40a and the foreign object 2, not coincident with the continuous curved portion of the dark area 40. FIG. The detection area line delimiter 342 of the present embodiment does not detect the dark portion 40 from the other end of the X axis, but detects the dark portion 40 toward one end from the bright contour line 5 offset by the offset portion 341 . By detecting the dark portion 40 from the offset bright portion outline 5, even if the shadow of the disturbance element such as the ring mark 132 exists in the bright portion 41, the shadow of the disturbance element can be made to correspond to the bottom portion 131 of the glass container 1. It is possible to reduce the risk of misidentification as the dark portion 40 . However, instead of offsetting the bright contour line 5, a reference line may be set on the other end side of the X axis from the spike portion 40a, and the dark portion 40 may be detected toward one end side from the reference line. The reference line may be any line, but may be, for example, a straight line extending parallel to the Y-axis. Alternatively, the bright portion contour line defining portion 340 and the offset portion 341 may be omitted, and the detection area line defining portion 342 may detect the dark portion 40 from the other end of the X axis.

After the detection area line defining unit 342 defines the detection area line 6, the shift amount calculation unit 343 calculates the shift amount of the X-axis coordinate of the detection area line 6 along the Y-axis. The shift amount calculator 343 of the present embodiment calculates the shift amount of the X-axis coordinate of the detection area line 6 between two consecutive Y-axis coordinates. However, the amount of deviation of the X-axis coordinates of the detection area line 6 in the Y-axis coordinates that are close to each other, such as within 10 pixels, may be calculated even if they are not continuous. Note that one pixel on the X axis can be about 0.015 mm. For example, since the detection area line 6 is continuous on one end side (upper side) of the Y-axis than the foreign object 2, the deviation amount is small. On the other hand, a large deviation amount is calculated before and after the foreign object 2 .

The peculiar area detection unit 344 scans the deviation amount of the X-axis coordinates from one end of the Y axis to the other end, and detects the peculiar area 7 where the detection area line 6 is discontinuous due to the foreign matter 2 . Within a predetermined coordinate range of the Y axis, the X axis coordinates of the detection area line 6 deviate from one end side of the X axis to the other end side by a predetermined amount or more, and the X axis coordinate of the detection area line 6 is shifted to the other end side of the X axis. The specific region 7 can be detected by searching for a region that deviates by a predetermined amount or more toward one end from the . By appropriately setting the Y-axis coordinate range to be found in association with the change in the X-axis coordinate of the detection area line 6, the peculiar region 7 where the detection area line 6 is discontinuous due to the foreign matter 2 and the spike portion 40a It is possible to distinguish between areas where the detection area line 6 is discontinuous. For example, an area in which the detection area line 6 reciprocates a width of 15 pixels or more about the X axis within 50 pixels about the Y axis can be detected as the unique area 7 . 50 pixels on the Y-axis are 3 mm when the resolution in the Y-axis direction is 0.06 mm/pixel, and 15 pixels on the X-axis are 0.225 mm when the resolution in the X-axis direction is 0.015 mm/pixel.

When the peculiar region 7 is detected, the detection area line correction unit 345 adjusts the X-axis of the detection area line 6 at the Y-axis coordinate before or after the peculiar region 7 according to the scanning direction of the deviation amount by the peculiar region detection unit 344. The coordinates are used to correct the detection area line 6 (see FIG. 6(d)). As described above, in the present embodiment, the singular region detection unit 344 scans the deviation amount of the X-axis coordinates from one end of the Y-axis toward the other end. The Y-axis coordinate before the singular region 7 can be the Y-axis coordinate immediately before the singular region 7 on one end side of the Y-axis. Similarly, the Y-axis coordinate after the unique region 7 can be the Y-axis coordinate immediately after the unique region 7 on the other end of the Y-axis. However, the detection area line 6 may be corrected using the X-axis coordinates of the detection area line 6 that is close to, for example, within 10 pixels, instead of just before or after. The detection area line 6 can be corrected by replacing the X-axis coordinate of the detection area line 6 in the unique area 7 with the X-axis coordinate before or after the unique area 7 . FIG. 6D shows a mode in which the X-axis coordinates of the detection area line 6 in the peculiar area 7 are replaced with the X-axis coordinates of the detection area line 6 immediately before the peculiar area 7 . Therefore, in the corrected detection area line 6, the X-axis coordinate of the portion that was the peculiar area 7 has a constant value. The detection area line 6 is corrected so that the X-axis coordinates of the portion that was the peculiar area 7 change continuously or intermittently from the X-axis coordinates before the peculiar area 7 to the X-axis coordinates after the peculiar area 7. good too.

The foreign matter detector 346 detects a dot-like dark portion corresponding to the foreign matter 2 between the corrected detection area line 6 and the other end of the X axis (the bright portion 41 side). Specifically, when there is a dark portion having an area equal to or less than a predetermined value (or an area within a predetermined range) between the detection area line 6 and the other end of the X axis (the bright portion 41 side), the dark portion is detected as a foreign matter. 2 is detected. For example, the foreign object 2 has 20 pixels (0.3 [mm]/0.015 [mm/pixel]) in the X-axis direction and 5 pixels (0.3 [mm]/0.06 [mm/pixel]) in the Y-axis direction. pixel]), and its area is 100 pixels. By setting the threshold value of the area so that a dark portion having an area of 100 pixels can be detected as the foreign matter 2, a square foreign matter 2 of 0.3 mm in length and width can be detected.

The foreign matter detection unit 346 uses the other end of the X-axis, a line obtained by offsetting the corrected detection area line 6 to the other end of the X-axis, or a straight line extending parallel to the Y-axis as a reference for the other end of the X-axis. , a dot-like dark portion corresponding to the foreign object 2 can be detected. A line obtained by offsetting the corrected detection area line 6 to the other end side of the X-axis and a straight line extending parallel to the Y-axis are located at a position of about 400 pixels from the dark portion 40 to the other end side of the X-axis. is arranged at a position closer to one end side of the X axis than the other end of . By using the lines closer to one end of the X-axis than the other end of the X-axis as a reference, it is possible to limit the inspection range of the dot-like dark portion corresponding to the foreign matter 2 and improve the processing speed.

If the peculiar region 7 is not detected by the peculiar region detection unit 344 and the detection area line 6 is not corrected by the detection area line correction unit 345, the foreign object detection unit 346 determines the detection area line 6 defined by the detection area line demarcation unit 342. and the other end of the X-axis (the bright portion 41 side), a dot-like dark portion corresponding to the foreign object 2 can be detected.

Next, FIG. 7 is a flow chart showing a glass container manufacturing method according to an embodiment of the present invention. As shown in FIG. 7, the glass container manufacturing method according to the present embodiment includes a blending step (step S1), a melting step (step S2), a forming step (step S3), a slow cooling step (step S4), and an inspection step ( step S5).

In the mixing step (step S1), raw materials are mixed at a predetermined ratio according to the properties of the glass container to be manufactured. Raw materials for the glass container include main raw materials such as silica sand, soda ash, lime and cullet, and auxiliary raw materials such as oxidizing agents, reducing agents, clarifying agents, decolorizing agents and coloring agents.

The melting step (step S2) is a step of heating and melting the raw materials blended in the blending step in a glass melting furnace to produce molten glass.

The forming step (step S3) is a step of forming a glass container from molten glass. An intermediate body called a parison can be formed from molten glass in a rough mold, and a glass container can be formed from the parison in a finishing mold.

The slow cooling step (step S4) is a step of introducing the glass container molded in the molding step into a slow cooling kiln and slowly cooling the glass container.

The inspection step (step S5) is a step of inspecting, using the foreign matter inspection apparatus 3 of the present embodiment, whether or not the foreign matter 2 is mixed in the hem bottom portion 13 of the glass container 1 that has been slowly cooled in the slow cooling step. is. The glass container 1 determined in the inspection process that the hem bottom 13 is not contaminated with the foreign matter 2 is conveyed to the next process such as packaging and shipping. On the other hand, the glass container 1 determined to contain the foreign matter 2 in the hem bottom portion 13 is stored for reinspection or discarded without being transported to the next process.

The inspection process includes a step of capturing an image of the hem bottom portion 13 of the foreign matter inspection device 3 with the camera 33, and a determination device 34 determining whether or not the hem bottom portion 13 contains foreign matter 2 based on the image captured by the camera 33. It includes the step of

In the step of determining whether or not the foreign matter 2 is mixed with the determining device 34, the X-axis detection is performed when the dark portion 40 is detected for the first time when the dark portion 40 is detected from the other end side to the one end side of the image on the X-axis. A detection area line defining step of defining a detection area line 6 by connecting coordinates in the Y-axis direction, a shift amount calculation step of calculating a shift amount of the X-axis coordinate of the detection area line 6 along the Y-axis, a peculiar area detection step of scanning the shift amount of the X-axis coordinate from one end to the other end to detect a peculiar area 7 where the detection area line 6 is discontinuous due to the foreign matter 2; a detection area line correction step of correcting the detection area line 6 using the X-axis coordinate of the detection area line 6 in the Y-axis coordinate before or after the unique area 7 related to the scanning direction, and the corrected detection area and a foreign object detection step of detecting a dot-like dark portion corresponding to the foreign object 2 between the line 6 and the other end of the X axis.

In addition, in the step of determining whether or not the foreign matter 2 is mixed with the determining device 34, the bright portion 41 is detected for the first time when the bright portion 41 is detected from one end of the image toward the other end of the X axis. and a bright contour defining step of defining a bright contour 5 by joining the X-axis coordinates of the Y-axis to the Y-axis, and an offset step of offsetting the bright contour 5 to the other end of the X-axis. good too. In this case, in the detection area line definition step, the detection area line 6 can be defined by detecting the dark portion 40 from the offset bright portion outline 5 toward one end side of the X axis.

In such a foreign matter inspection apparatus and a glass container manufacturing method using the same, since the imaging lens 332 is attached to the camera body 330 while being turned upside down via the reverse ring 331, the expensive imaging lens 332 is not required. It is also possible to obtain an image suitable for finding minute foreign matter. As a result, minute foreign matter can be found more reliably while suppressing apparatus costs.

Further, the camera 33 is arranged so as to pick up an image of the skirt bottom portion 13 from obliquely below, and the elevation angle of the optical axis 33a of the camera 33 is 33° or more and 43° or less. of the foreign matter 2 can be imaged in a well-balanced manner, and the detection accuracy of the foreign matter 2 can be improved.

In addition, since the depth of field of the camera 33 is 1.5 mm or more and 5.0 mm or less, it is possible to improve the detection accuracy of the foreign object 2 by suppressing the influence of disturbance factors while ensuring ease of focusing.

In addition, since the light source 32 irradiates the glass container 1 with an illuminance of 1700 lx or more, the shadow of the disturbance element can be more reliably erased or reduced in the image of the hem bottom 13 of the glass container 1 captured by the camera 33. can be performed, and the detection accuracy of the foreign matter 2 based on the image can be improved.

Moreover, since the light control film 320 is attached to the light source 32 to limit the diffusion of the light from the light source 32, the influence of the light on the surroundings of the foreign matter inspection apparatus 3 can be suppressed. Light control film 320 is particularly useful when using a high intensity light source as light source 32 .

In addition, the light source 32 causes light to enter the ring mark 132 at an angle that is inclined with respect to the horizontal by an angle obtained by adding an angle θ2 of 12° or more and 22° or less to the elevation angle θ1 of the optical axis 33a of the camera 33. The possibility that the shadow of the mark 132 appears in the image of the camera 33 can be reduced, and the detection accuracy of the foreign object 2 can be improved.

Further, when the peculiar area 7 is detected, the determination device 34 corrects the detection area line 6 and then detects the dot-like dark portion corresponding to the foreign matter 2, so that the minute foreign matter can be detected more reliably.

Further, since the detection area line delimiter 342 detects the dark portion 40 toward one end side of the X-axis from the offset bright portion contour line 5 and demarcates the detection area line 6, the ring mark 132 or the like is detected in the bright portion 41. Even if the shadow of the disturbance element is present, the possibility of erroneously recognizing the shadow of the disturbance element as the dark portion 40 corresponding to the bottom portion 131 of the glass container 1 can be reduced.

In the embodiment, the imaging lens 332 is attached to the camera body 330 by being turned upside down via the reverse ring 331, but the imaging lens 332 is attached to the camera body 330 without being turned upside down. The determination device 34 may determine the presence of the foreign matter 2 based on the image captured in .

Reference Signs List 1 glass container 13 hem bottom portion 130 hem portion 131 bottom portion 132 ring mark 2 foreign matter 3 foreign matter inspection device 32 light source 320 light control film 33 camera 33a optical axis 330 camera body 331 reverse ring 332 imaging lens 34 determination device 340 bright area outline defining unit 341 offset unit 342 detection area line definition unit 343 deviation amount calculation unit 344 unique area detection unit 345 detection area line correction unit 346 foreign object detection unit 40 dark area 41 bright area 5 bright area contour line 6 detection area line 7 unique area

Claims (10)

a light source that irradiates the glass container with light;
a camera for imaging the hem bottom of the glass container;
a determination device that determines whether or not foreign matter is mixed in the skirt bottom based on the image captured by the camera,
The camera is
camera body and
a reverse ring attached to the camera body;
an imaging lens attached to the camera body by being turned upside down via the reverse ring;
the image includes two-dimensional pixel data having an X-axis and a Y-axis;
The image includes a dark portion located on one end side of the X-axis and corresponding to the bottom of the glass container, and a bright portion located on the other end side of the X-axis and corresponding to the bottom portion of the glass container. and
In the image, the foreign matter appears as a dot-like dark portion in a bright portion corresponding to the bottom portion of the glass container,
The determination device is
a detection area line defining unit that defines a detection area line by connecting in the Y-axis direction the X-axis coordinates at which the dark portion is detected for the first time when the dark portion is detected from the other end side of the X-axis toward one end side; ,
a shift amount calculation unit that calculates a shift amount of the X-axis coordinate of the detection area line along the Y-axis;
a peculiar area detection unit that scans the deviation amount of the X-axis coordinates from one end of the Y-axis toward the other end to detect a peculiar area where the detection area line is discontinuous due to the foreign matter;
A detection area line correction unit for correcting the detection area line using the X-axis coordinate of the detection area line in the Y-axis coordinates before or after the specific area in the scanning direction when the specific area is detected. and,
a foreign object detection unit that detects a dotted dark part corresponding to the foreign object between the corrected detection area line and the other end of the X axis;
have,
Foreign object inspection device. The camera is arranged to capture an image of the hem bottom from obliquely below,
The elevation angle of the optical axis of the camera is 33° or more and 43° or less.
A foreign matter inspection apparatus according to claim 1. The camera has a depth of field of 1.5 mm or more and 5.0 mm or less.
The foreign matter inspection device according to claim 1 or 2. The light source irradiates the glass container with an illuminance of 1700 lx or more.
The foreign matter inspection device according to any one of claims 1 to 3. The light source is fitted with a light control film that limits the diffusion of light from the light source.
The foreign matter inspection device according to any one of claims 1 to 4. A ring mark is provided on the outer peripheral surface of the hem bottom,
The light source causes light to enter the ring mark at an angle inclined with respect to the horizontal by an angle equal to or greater than 12° and equal to or less than 22° to the elevation angle of the optical axis of the camera.
The foreign matter inspection device according to any one of claims 1 to 5. The determination device is
Defining a bright portion outline by linking the X-axis coordinates at which the bright portion is detected for the first time when the bright portion is detected from one end of the X axis toward the other end to the Y axis to define a bright portion outline. Department and
and an offset portion that offsets the bright portion contour line to the other end side of the X axis,
The detection area line demarcation unit detects the dark part toward one end side from the offset bright part outline to demarcate the detection area line.
The foreign matter inspection device according to any one of claims 1 to 6 . a light source that irradiates the glass container with light;
a camera for imaging the hem bottom of the glass container;
a determination device that determines whether or not foreign matter is mixed in the skirt bottom based on the image captured by the camera,
the image includes two-dimensional pixel data having an X-axis and a Y-axis;
The image includes a dark portion located on one end side of the X-axis and corresponding to the bottom of the glass container, and a bright portion located on the other end side of the X-axis and corresponding to the bottom portion of the glass container. and
In the image, the foreign matter appears as a dot-like dark portion in a bright portion corresponding to the bottom portion of the glass container,
The determination device is
a detection area line defining unit that defines a detection area line by connecting in the Y-axis direction the X-axis coordinates at which the dark portion is detected for the first time when the dark portion is detected from the other end side of the X-axis toward one end side; ,
a shift amount calculation unit that calculates a shift amount of the X-axis coordinate of the detection area line along the Y-axis;
a peculiar area detection unit that scans the deviation amount of the X-axis coordinates from one end of the Y-axis toward the other end to detect a peculiar area where the detection area line is discontinuous due to the foreign matter;
A detection area line correction unit for correcting the detection area line using the X-axis coordinate of the detection area line in the Y-axis coordinates before or after the specific area in the scanning direction when the specific area is detected. and,
a foreign object detection unit that detects a dot-like dark part corresponding to the foreign object between the corrected detection area line and the other end of the X-axis,
Foreign object inspection device. The determination device is
Defining a bright portion outline by linking the X-axis coordinates at which the bright portion is detected for the first time when the bright portion is detected from one end of the X axis toward the other end to the Y axis to define a bright portion outline. Department and
and an offset portion that offsets the bright portion contour line to the other end side of the X axis,
The detection area line demarcation unit detects the dark part toward one end side from the offset bright part outline to demarcate the detection area line.
A foreign matter inspection apparatus according to claim 8 . A step of inspecting whether foreign matter is mixed in the bottom of the glass container using the foreign matter inspection device according to any one of claims 1 to 9 ,
Glass container manufacturing method.

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