JP2012122912A - Determination method of inspection region and foreign matter inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a foreign matter inspection device that can cope with shape variation of a test object without needing detection of positional deviation of the test object, and can cope with minute shape variation due to the positional deviation of the test object on a transporting device such as a conveyer.SOLUTION: A determination method of an inspection region used when conducting an inspection for detecting a defect of a glass bottle 1 or a foreign matter in the glass bottle 1 by imaging the glass bottle 1, includes a step of obtaining an image of a bottle bottom 1a by imaging the bottle bottom 1a of the glass bottle 1 with a camera 3, a step of detecting, from the image, a baffle mark that is formed at a lower end of the bottle bottom when molding the glass bottle 1, and a step of determining the inspection region in the image by using the detected baffle mark.

Description

  The present invention relates to a method for determining an inspection area when performing an inspection to detect a defect in a glass bottle or a foreign substance in the glass bottle by imaging a glass bottle. The present invention also relates to a foreign substance inspection apparatus that images a glass bottle and inspects whether or not there is a foreign substance at the bottom of the glass bottle.

In some cases, foreign substances such as rubber packing pieces and glass pieces are mixed in a glass bottle filled with a liquid such as a beverage. Foreign objects often settle on the bottom of the glass bottle. Therefore, after filling a glass bottle with a liquid such as a beverage, an inspection is performed to determine whether or not foreign matter has precipitated at the bottom or near the bottom of the bottle. In order to automatically inspect foreign matter that has settled on the bottom of the glass bottle while the glass bottle is being transported by a conveyor or other transport device, the bottom of the glass bottle is imaged from the diagonally upper side of the glass bottle. Therefore, it is necessary to create an inspection region by specifying the position and shape.
Conventionally, an inspection area for automatic inspection is created by the following procedure. First, a fixed shape of an inspection area is set in advance, and an edge of a specific part of the eyelid is detected at a preset position (fixed position) from an image obtained by photographing the eyelid for inspection. As a result, the position of the eyelid in the XY direction is specified, the position shift amount in the XY direction is detected based on the specified position in the XY direction, and automatic inspection is performed by moving the inspection area according to the position shift amount. An inspection area is created for.

Japanese Patent Laid-Open No. 5-99861 JP 2001-27614 A

The above-described conventional method for creating an inspection area for automatic inspection has the following problems.
(1) Since the inspection area has a fixed shape, if the glass bottle to be inspected shifts back and forth on the conveyor and the image size changes, the inspection area shape must be set in anticipation of the amount of change. Don't be. For this reason, not only the setting takes time, but also the inspection area is set small, which is disadvantageous for inspection.
(2) It is necessary to detect the amount of positional deviation in the XY direction of the inspection target, and a window capable of detecting a stable positional deviation amount in the XY direction for each inspection must be set in advance. If the window is not set properly, the inspection image and the inspection area will be misaligned, causing erroneous detection. Further, when the positional deviation amount cannot be detected, the positional deviation amount is predicted in advance, and the inspection area is set to be small by the positional deviation amount, which is disadvantageous for inspection.

  The present invention has been made in view of the above-described circumstances, can cope with variations in the shape of an inspection target, does not need to detect the amount of positional displacement of the inspection target, and is the position of the inspection target on a transport device such as a conveyor. It is an object of the present invention to provide an inspection region determination method and a foreign matter inspection apparatus that can cope with a minute size and shape change due to variations in size.

In order to achieve the above-mentioned object, the present inventors conducted earnest research on a method for creating an inspection region for automatic inspection, and obtained the following knowledge.
At the bottom of the glass bottle, the shape of the bottom outer part (outer side part) is constant, but the shape of the bottom bottom part (the inner surface of the bottom) changes from one bowl to another, making it difficult to specify the shape. Moreover, in the case of a cocoon that is difficult to transmit light, such as a brown cocoon, a cocoon shadow is formed on a conveying device such as a conveyor, so that it is difficult to detect the heel bottom outer portion (the outer heel portion). Furthermore, since the shape of the top part of the bottom of the bottom (the raised part of the central part of the inner surface of the bottom) is not constant, it is difficult to detect the bottom part of the bottom (the inner surface of the bottom) by detecting the top part. Therefore, it is difficult to specify the vertical position of the bag.

The inventors of the present invention have a baffle mark (or parting line) formed at the bottom bottom portion of the bottom of the glass bowl when forming the glass bowl, and has a position and a shape that substantially coincide with the bottom bottom part (bottom inner surface). Focusing on this, the idea is to detect and use baffle marks in order to identify the bottom bottom inner side shape (bottom bottom inner surface shape).
That is, the method for determining an inspection area of the present invention is a method for determining an inspection area when performing an inspection to detect defects in the glass bottle or foreign matter in the glass bottle by imaging the glass bottle. The bottom of the heel is photographed with a camera to obtain an image of the heel, and the baffle mark that can be formed at the bottom of the heel is detected from the image, and the image is inspected using the detected baffle mark. A region is determined.

  According to the present invention, the diffused light from the illumination is incident from the illuminating side surface portion of the glass jar on the illuminating side, reflected from the heel bottom portion, and incident on the camera side from the heel side surface portion and photographed. The image of the heel bottom imaged by the camera is subjected to image processing, and a baffle mark at the bottom edge of the heel bottom is detected. Then, the inspection area is determined in the image using the detected baffle mark. Since this baffle mark is in a position close to the bottom bottom inner shape (the bottom inner surface shape), it is used as a reference for determining the inspection region.

According to a preferred aspect of the present invention, a lower end line of the inspection area is determined from the detected baffle mark.
According to the present invention, since the baffle mark is close to the bottom bottom inner shape (bottom bottom inner shape), if the bottom line of the inspection area is determined from the detected baffle mark, the labor of the bowl shape measurement can be saved, It can also handle variations in the shape of each bowl. In addition, it is possible to cope with minute shape changes due to variations in the wrinkle position on a conveying device such as a conveyor.

According to a preferred aspect of the present invention, a bottom line of the inspection area is determined by applying a Laplace filter to the image to reveal the baffle mark.
According to a preferred aspect of the present invention, gamma correction is performed on the image to reveal the baffle mark, thereby determining the lower end line of the inspection area.

According to a preferred aspect of the present invention, the lower end line of the inspection region is represented by an elliptic equation.
According to the present invention, since the lower end line of the inspection area can be expressed by an elliptic equation, the lower end line of the inspection area can be clearly identified on the image.

According to a preferred aspect of the present invention, scanning is performed from the lower end line of the inspection area toward the upper side of the image, and the upper end of the inspection area is detected as a start point of an area in which pixels having a certain brightness or higher continue. It is characterized by determining by doing.
According to the present invention, since the baffle mark is directly below the bottom bottom inner shape (bottom bottom inner surface shape), the image is scanned upward from the bottom line of the inspection area determined from the detected baffle mark. Since the part slightly above the inner bottom edge shape (inner bottom inner surface shape) is a bright image portion in the image, there is no need to determine the upper end of the inspection area in advance, and the lower end of the inspection area. The image can be automatically determined by scanning the image upward from the line and detecting the start point of a region in which pixels of a certain brightness or higher continue.

  The foreign matter inspection apparatus according to the present invention is an apparatus that images a glass bottle while the glass bottle is being conveyed along a predetermined conveyance path and inspects whether or not there is a foreign substance at the bottom of the glass bottle. It is arranged on the side of the glass bottle that is transported along the side of the glass bottle, and illuminates the inside of the glass bottle, and is arranged opposite to the illumination with the glass bottle in between, and shoots the transmitted light that has passed through the bottom of the glass bottle. And an image processing device that processes an image obtained by photographing the bottom of the bottom with the camera. The image processing device detects, from the image, a baffle mark that can be formed at the bottom end of the bottom of the glass when forming a glass bottle. The inspection area is determined in the image using the detected baffle mark.

  According to the present invention, the diffused light from the illumination is incident from the illuminating side surface portion of the glass jar on the illuminating side, reflected from the heel bottom portion, and incident on the camera side from the heel side surface portion and photographed. The image of the heel bottom imaged by the camera is subjected to image processing by an image processing device, and a baffle mark at the bottom edge of the heel bottom is detected. Then, the inspection area is determined in the image using the detected baffle mark. Since this baffle mark is in a position close to the bottom bottom inner shape (the bottom inner surface shape), it is used as a reference for determining the inspection region.

According to a preferred aspect of the present invention, the glass bottle is conveyed along a straight conveyance path by a conveyor.
According to the present invention, the illumination is arranged on one side of the conveyor, the camera is arranged on the other side of the conveyor, and the foreign object at the bottom of the glass bottle while the glass bottle is being conveyed along the straight conveyance path by the conveyor. Can be detected.

According to a preferred aspect of the present invention, the image processing apparatus determines a lower end line of the inspection area from the detected baffle mark.
According to the present invention, since the baffle mark is close to the bottom bottom inner shape (bottom bottom inner shape), if the bottom line of the inspection area is determined from the detected baffle mark, the labor of the bowl shape measurement can be saved, It can also handle variations in the shape of each bowl. In addition, it is possible to cope with minute shape changes due to variations in the wrinkle position on a conveying device such as a conveyor.

According to a preferred aspect of the present invention, the lower end line of the inspection region is represented by an elliptic equation.
According to the present invention, since the lower end line of the inspection area can be expressed by an elliptic equation, the lower end line of the inspection area can be clearly identified on the image.

According to a preferred aspect of the present invention, the image processing apparatus scans from the lower end line of the inspection area toward the upper side of the image to obtain a bright / dark edge and detect a foreign object. .
According to the present invention, since the baffle mark is directly below the bottom bottom inner shape (bottom bottom inner surface shape), if the image is scanned upward from the bottom line of the inspection area determined from the detected baffle mark, the scan is performed. The necessary range can be minimized, there is no useless scanning area, and no foreign matter is detected on the outer side of the lower side of the inspection area.

According to a preferred aspect of the present invention, the image processing apparatus determines the upper end of the inspection region by detecting a start point of a region in which pixels having a certain brightness or higher continue. .
According to the present invention, since the part slightly above the inner bottom bottom inner shape (the inner bottom shape) is a bright image portion in the image, the upper end of the inspection area needs to be determined in advance. Instead, it can be automatically determined by scanning the image upward from the lower end line of the inspection area and detecting the start point of the area in which pixels having a certain brightness or higher continue.

The present invention has the following effects.
(1) In order to identify the bottom bottom inner shape (bottom inner surface shape), the baffle mark that is considered to be closest to it is detected and the inspection area is determined, so that the labor for measuring the hook shape can be saved. It can cope with the shape variation. In addition, it is possible to cope with minute shape changes due to variations in the wrinkle position on a conveying device such as a conveyor.
(2) By detecting the baffle mark and determining the inspection area, it is possible to specify the inspection position without being influenced by the shape variation of each basket or the position variation on the transfer device such as the conveyor.

FIG. 1 is a schematic elevation view showing the configuration of a foreign matter inspection apparatus using the inspection region determination method according to the present invention. FIG. 2 is an original image taken by the camera. FIG. 3 is an image in which a baffle mark is made visible by applying a Laplace filter to the original image shown in FIG. FIG. 4 is a drawing in which the lower end line of the inspection area calculated using the elliptic equation obtained from the baffle mark shown in FIG. 3 is overlaid on the original image shown in FIG. It is a figure which scans to the upper end of an inspection area | region from the inspection area lower end line to the upper direction of an image by making an inspection area lower end line into the lower end of an inspection area. FIG. 3 is an image in which baffle marks are made obvious by performing gamma correction on the original image shown in FIG. 2.

  Embodiments of a method for determining an inspection area and a foreign substance inspection apparatus according to the present invention will be described below with reference to FIGS. 1 to 6, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic elevation view showing the configuration of a foreign matter inspection apparatus using the inspection region determination method according to the present invention. As shown in FIG. 1, the illumination 2 is arranged on the back surface of the glass bowl 1 conveyed by the conveyor C, and the camera 3 is arranged on the opposite side of the illumination 2 across the glass bowl 1. Here, a glass bottle 1 having a circular outer periphery at the bottom is taken as the inspection object. The illumination 2 is composed of red LED illumination in which red LEDs are arranged vertically and horizontally, and the illumination surface 2a on the front surface thereof is parallel to the casing of the glass barrel 1. The illuminator 2 projects diffused light on the barrel body and the bottom of the glass bowl 1. The camera 3 is a CCD camera, and the optical axis 3x of the camera 3 intersects with the axis 1x of the glass bottle 1 at the lower end of the bottle so that the predetermined angle (θ) = 10 ° to 50 ° obliquely downward with respect to the horizontal plane. ° Inclined. In the illustrated example, the angle (θ) is 20 °. An image processing device 5 is connected to the camera 3.

  In the foreign matter inspection apparatus configured as shown in FIG. 1, the diffused light from the illumination 2 is incident on the outer peripheral surface of the bottom 1 a of the glass bottle 1. The light incident on the bottom 1a of the glass bottle 1 is transmitted through the bottom 1a of the glass bottle 1, and the transmitted light is incident on the camera 3 and photographed.

FIG. 2 is an original image obtained by photographing a brown glance with the camera 3 of the foreign substance inspection apparatus shown in FIG. An image captured by the camera 3 is subjected to image processing by the image processing device 5. This image is subjected to image processing according to the following procedure (steps 1 to 3).
Step 1)
An Laplace filter is applied to the original image shown in FIG. 2 to obtain an image in which baffle marks are actualized. That is, an edge component in the original image is emphasized by a Laplace filter to obtain a region boundary line. FIG. 3 is an image in which baffle marks are made apparent. As shown in FIG. 3, an elliptical baffle mark that is a lower half of the long axis becomes apparent at the lower end of the bottom of the glass bottle.

Step 2)
A point on the baffle mark is obtained, and elliptical approximation is performed by the least square method based on the point coordinates (Xi, Yi) to obtain an elliptical shape. The obtained elliptical shape is represented by the following elliptic equation, where A is the long radius, B is the short radius, and (Xo, Yo) is the center coordinate of the ellipse.
^{(Xi-Xo) 2 / A} 2 + (Yi-Yo) 2 / B 2 = 1 ··· (1)
Therefore, the lower end line of the inspection area is expressed by the above elliptic equation (1). 2 is obtained by superimposing the actual examination region lower end line shown in FIG. 3 on the original image shown in FIG. 2, and the ellipse center (Xo, Yo), the upper end of the ellipse (Yo + B), and the right end of the ellipse (Xo + A). ), An ellipse left end (Xo-A) is shown in FIG.

Step 3)
Next, as shown in FIG. 5, the lower end line of the inspection area obtained from the detected baffle mark is the lower end of the inspection area, the left end of the lower end line of the inspection area is the left end of the inspection area, and the right end of the lower end line of the inspection area is the right end of the inspection area. And Scanning is performed from the lower end line of the inspection area toward the upper side of the image, and a bright and dark edge is obtained to detect foreign matters such as glass pieces and black rubber. The upper end of the inspection area can be automatically obtained by detecting the start point of an area in which pixels having a certain brightness or higher continue. If the foreign object is a light-shielding foreign object such as black rubber, the foreign object appears as a dark shadow in the background of the specified brightness in the image, so image processing is performed to determine whether there is a dark shadow in the created inspection area. A foreign object is detected by the determination by the device 5. In addition, when the foreign matter is a reflective foreign matter such as a glass piece, the foreign matter is diffusely reflected and brightly shined, so the foreign matter appears as a bright spot (or region) in the background of a predetermined brightness in the image. The foreign matter is detected by determining whether or not there is a bright spot (or region) in the created inspection region by the image processing device 5. FIG. 5 shows an image in which a foreign object such as a glass piece or black rubber is detected. The detected glass piece is drawn in white and the black rubber is drawn in black.

  In step 1 described above, a Laplace filter is applied to the original image shown in FIG. 2 to reveal the baffle mark, but it is also possible to make the baffle mark actual by performing gamma correction on the original image. FIG. 6 is an image in which the original image shown in FIG. Also in this case, as is apparent from FIG. 6, an elliptical baffle mark having a lower half of the major axis becomes apparent at the lower end of the bottom of the glass bottle. After performing the gamma correction, the processing is performed in the same procedure as in Step 2 and Step 3 above.

  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 Glass bottle 1a Glass bottom 1x Axis 2 Illumination 2a Illumination surface 3 Camera 3x Optical axis

Claims (12)

A method for determining an inspection area when performing an inspection to detect a defect in the glass bottle or a foreign substance in the glass bottle by imaging the glass bottle,
Take a picture of the bottom of the glass wall with a camera to get an image of the bottom of the glass wall,
From the image, when forming a glass bottle, a baffle mark that can be formed on the lower edge of the bottle bottom is detected,
A method for determining an inspection area, wherein an inspection area is determined in an image using a detected baffle mark.   2. The inspection area determination method according to claim 1, wherein a lower end line of the inspection area is determined from the detected baffle mark.   3. The inspection area determination method according to claim 2, wherein a bottom line of the inspection area is determined by applying a Laplace filter to the image to reveal the baffle mark.   3. The inspection area determination method according to claim 2, wherein a lower end line of the inspection area is determined by performing gamma correction on the image and revealing the baffle mark.   The method according to claim 2, wherein a lower end line of the inspection area is represented by an elliptic equation.   The image is scanned from the lower end line of the inspection area toward the upper side of the image, and the upper end of the inspection area is determined by detecting a start point of an area in which pixels having a certain brightness or higher continue. The method for determining an inspection area according to any one of claims 2 to 5. In an apparatus for inspecting whether there is a foreign object at the bottom of the glass bottle by imaging the glass bottle while the glass bottle is being conveyed along a predetermined conveyance path,
Illuminated to illuminate the inside of the glass bottle, disposed on the side of the glass bottle conveyed along the conveyance path,
A camera that is arranged to face the illumination across the glass jar and that captures the transmitted light that has passed through the heel of the glass jar,
An image processing device for processing an image obtained by photographing the bottom of the heel with the camera,
The image processing device detects a baffle mark formed at a bottom lower end portion of the glass bottom when forming a glass bottle from the image, and determines an inspection region in the image using the detected baffle mark. Foreign matter inspection device.   The foreign matter inspection apparatus according to claim 7, wherein the glass bottle is conveyed along a straight conveyance path by a conveyor.   The foreign matter inspection apparatus according to claim 7, wherein the image processing apparatus determines a lower end line of the inspection region from the detected baffle mark.   The foreign matter inspection apparatus according to claim 9, wherein a lower end line of the inspection area is represented by an elliptic equation.   The foreign matter inspection apparatus according to claim 9, wherein the image processing device scans from the lower end line of the inspection area toward the upper side of the image to obtain a bright and dark edge to detect the foreign matter.   12. The foreign matter inspection apparatus according to claim 11, wherein the image processing apparatus determines the upper end of the inspection area by detecting a start point of an area where pixels having a certain brightness or higher continue.

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