WO2023089954A1

WO2023089954A1 - Glass bottle bottom inspection device

Info

Publication number: WO2023089954A1
Application number: PCT/JP2022/035581
Authority: WO
Inventors: 怜也松本
Original assignee: 東洋ガラス株式会社
Priority date: 2021-11-22
Filing date: 2022-09-26
Publication date: 2023-05-25
Also published as: JP2023075992A

Abstract

This glass bottle bottom inspection device comprises an illumination device that radiates light toward the bottom of a glass bottle, a camera that is disposed on the other side of the glass bottle from the illumination device and that captures an image of the bottom, a first circularly polarizing film, and a second circularly polarizing film. The illumination device comprises a first illumination unit that radiates infrared light having directivity toward the bottom, and a second illumination unit that is disposed between the first illumination unit and the bottom and that radiates visible light having diffusivity toward the bottom. The camera comprises a first light receiving unit that detects only infrared light, and a second light receiving unit that detects only visible light. The first circularly polarizing film and the second circularly polarizing film have the same polarization direction.

Description

Glass bottle bottom inspection device

The present invention relates to a glass bottle bottom inspection device.

A visual inspection device for inspecting defects in the bottom of transparent bottles such as PET bottles has been proposed (for example, Patent Document 1). This visual inspection device irradiates blue (450 nm to 490 nm) diffused light and red (620 nm to 750 nm) parallel light toward the bottom outer surface of a transparent PET bottle, and uses two types of cameras placed on the mouth side. are captured and compared to determine the presence or absence of a defect.

JP 2012-242148 A

In general, the bottom of the glass bottle has many uneven engravings such as company logos and control numbers. Therefore, for example, even if the technique of Patent Document 1 is applied to a glass bottle, it is difficult to distinguish between the engraving pattern and the defect in the image, and the inspection accuracy is lowered so as not to mistakenly recognize the pattern as a defect. Different inspections will be performed on the equipment.

Therefore, the present invention provides a glass bottle bottom inspection device that can determine the presence or absence of defects with a high degree of accuracy even in glass bottles that have uneven engravings on the bottom.

The present invention has been made to solve at least part of the above problems, and can be implemented as the following aspects or application examples.

In the following explanation, "sculpture" refers to changes in shape due to unevenness on the surface of the glass bottle, and "pattern" refers to the contrast density resulting from the "sculpture" that appears in the image obtained by photographing the glass bottle. Change.

[1] One aspect of the glass bottle bottom inspection device according to the present invention is
a lighting device that irradiates light toward the bottom of the glass bottle;
a camera placed across the glass bottle with respect to the lighting device and capturing an image of the bottom;
a first circularly polarizing film disposed between the lighting device and the bottom;
a second circularly polarizing film disposed between the mouth of the glass bottle and the camera;
with
The lighting device includes a first lighting unit that emits infrared light having directivity toward the bottom, and a diffusing property toward the bottom that is disposed between the first lighting unit and the bottom. and a second illumination unit that emits visible light,
The camera includes a first light receiving unit that detects only infrared light and a second light receiving unit that detects only visible light,
The first circularly polarizing film and the second circularly polarizing film have the same polarization direction.

[2] In one aspect of the glass bottle bottom inspection device,
The camera can include a beam splitter that separates infrared light and visible light.

[3] In one aspect of the glass bottle bottom inspection device,
The first illumination unit includes a first light source that emits diffuse infrared light, and a louver film having a plurality of louvers that limit the angle of transmission of the infrared light incident from the first light source. ,
In the louver film, the plurality of louvers may extend in a grid pattern in a direction perpendicular to the central axis of the glass bottle.

[4] In one aspect of the glass bottle bottom inspection device,
The louver film may have a viewing angle of 15 to 45 degrees on the central axis.

According to one aspect of the apparatus for inspecting the bottom of a glass bottle according to the present invention, the pattern can be detected from the image of the first light-receiving part even if the glass bottle has uneven engravings on the bottom. It is easy to determine the presence or absence of a defect in an area without a pattern.

FIG. 1 is a front view schematically showing one aspect of the bottom inspection device. FIG. 2 is a partially enlarged view schematically showing the louver film. FIG. 3 is a flow chart of an inspection method using a bottom inspection device. FIG. 4 is an example of the first image. FIG. 5 is an example of the second image. FIG. 6 is a diagram for explaining the inspection area setting process. FIG. 7 is an example of the third image. FIG. 8 shows first and second images captured by the bottom inspection apparatus of Example 1. FIG. 9A and 9B are first and second images captured by the bottom inspection apparatus of Comparative Example 1. FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail using the drawings. It should be noted that the embodiments described below do not unduly limit the scope of the invention described in the claims. Moreover, not all the configurations described below are essential constituent elements of the present invention.

One aspect of the glass bottle bottom inspection apparatus according to the present embodiment includes a lighting device that irradiates light toward the bottom of the glass bottle, and a lighting device that is arranged to sandwich the glass bottle with respect to the lighting device. a camera for capturing images, a first circularly polarizing film positioned between the lighting device and the bottom, and a second circularly polarizing film positioned between the mouth of the vial and the camera; and the lighting device includes: a first lighting unit that emits infrared light having directivity toward the bottom; a second illumination unit that irradiates visible light having a property, the camera includes a first light receiving unit that detects only infrared light, and a second light receiving unit that detects only visible light; The polarization directions of the first circularly polarizing film and the second circularly polarizing film are the same.

1. Bottom Inspection Apparatus A bottom inspection apparatus 1 for a glass bottle 10 according to the present embodiment will be described in detail with reference to FIGS. 1 and 2. FIG. FIG. 1 is a front view schematically showing one aspect of the bottom inspection apparatus 1, and FIG. 2 is a partially enlarged view schematically showing the louver film 24. As shown in FIG.

As shown in FIG. 1 , the bottom inspection device 1 for glass bottles 10 includes an illumination device 2 , a camera 4 , a first circularly polarizing film 35 and a second circularly polarizing film 36 . The bottom inspection device 1 may be incorporated as part of a production line for the vials 10 or an inspection line comprising a plurality of inspection devices, in which case means may also be provided for loading and unloading the vials 10 into and out of the bottom inspection device 1. good. The bottom inspection device 1 may further include a controller 50 .

The glass bottle 10 has a mouth portion 13 , a body portion 14 and a bottom portion 15 downward along the central axis 12 of the glass bottle 10 . A glass bottle 10 to be inspected is arranged at a predetermined position on the mounting table 60 of the bottom inspection device 1 . The central axis 12 is an imaginary line passing through the center of the mouth portion 13 and the center of the bottom portion 15 . The mounting table 60 is a table on which the glass bottle 10 is placed, and at least the range on which the bottom part 15 is placed is composed of a flat plate that transmits visible light and infrared light, such as a distortion-free transparent acrylic resin plate or glass plate. Alternatively, the mounting table 60 may be removed and the glass bottle 10 may be imaged while floating in the air. The glass bottle 10 is made of glass, is a transparent or translucent container, and may be colored. Translucency is a degree of transparency that allows the light from the lighting device 2 transmitted through the glass bottle 10 to determine defects in the bottom 15 . The mouth part 13 is opened and a lid is attached after filling the contents. The trunk portion 14 has a circular cross section, but may have another shape such as a substantially square shape. The bottom part 15 has a grounding peripheral edge and a bottom part consisting of the inner side of the peripheral edge, and has engravings on the outer surface. The engraving is an uneven character or symbol formed on the surface of the glass bottle 10. For example, the engraving is formed by the unevenness engraved on the surface of the mold during molding. The engraving is, for example, a company mark representing a manufacturing company and a model number representing a management number such as a mold number. Since the engraving is formed at a predetermined position on the bottom 15 corresponding to the unevenness of the mold, the pattern derived from the engraving is used for positioning the glass bottle 10 around the central axis 12 and for positioning the image taken by the camera 4. can do.

The illumination device 2 irradiates light toward the bottom 15 of the glass bottle 10 . The illumination device 2, the camera 4 and the glass bottle 10 are arranged so that the light emitted from the illumination device 2 passes through the bottom portion 15, passes through the body portion 14, passes through the opening of the mouth portion 13, and is received by the camera 4. placed. In this embodiment, the illumination device 2, the glass bottle 10, and the camera 4 are arranged in this order along the central axis 12, but other arrangements may be used as long as the camera 4 can receive the light transmitted through the bottom portion 15. FIG.

The illumination device 2 includes a first illumination section 21 that irradiates infrared light having directivity toward the bottom section 15 , and a diffusing property toward the bottom section 15 that is arranged between the first illumination section 21 and the bottom section 15 . and a second illumination unit 31 that emits visible light. In the example of FIG. 1, along the central axis 12, the first illumination unit 21, the second illumination unit 31, the first circularly polarizing film 35 described later, the mounting table 60, the glass bottle 10, the second circularly polarizing film 36, the camera 4 are arranged in order. Therefore, infrared light and visible light reach the bottom portion 15 . By using two types of light having different wavelengths (infrared light and visible light), the camera 4 can detect the two types of light with separate light receiving units. Here, visible light has a wavelength of 380 nm to 630 nm, and infrared light has a wavelength of 800 nm to 1000 nm.

The first illumination unit 21 has a first light source 22 that emits diffuse infrared light, and a plurality of louvers 24a (FIG. 2) that limit the angle of transmission of the infrared light incident from the first light source 22. and a louver film 24 . The infrared light transmitted through the louver film 24 has directivity.

The first light source 22 includes, for example, a plurality of LEDs (light emitting diodes) (not shown) and a diffusion plate 23 arranged on the bottom 15 side so as to cover the plurality of LEDs. An organic EL may be used instead of the LED. The first light source 22 is a planar surface light source that spreads on a plane perpendicular to the central axis 12 . A plurality of LEDs are evenly arranged on the surface on the diffuser plate 23 side and face the bottom 15 of the glass bottle 10 . Irradiate diffused light from the whole. Near-infrared light having a peak wavelength of 800 nm to 1000 nm is preferable as the infrared light emitted from the first illumination unit 21 .

As shown in FIG. 2, the louver film 24 can have a plurality of louvers 24a extending in a grid pattern in a direction orthogonal to the central axis 12 of the glass bottle 10. The louver film 24 is arranged so as to overlap the entire first light source 22 when viewed from the bottom 15 side. As the grid-like louver film 24, for example, a cross louver film manufactured by Shin-Etsu Polymer Co., Ltd. can be used. The louver film 24 consists of a plurality of plate-shaped louvers 24a with excellent light shielding properties and two louver films in which portions with excellent translucency are alternately arranged between the louvers 24a. It is configured to form a lattice when viewed from the axis 12 . The louver film 24 can be made of resin, for example. The louver film 24 allows the diffused light from the first light source 22 to have directivity. The viewing angle of the louver film 24 at the center axis 12 is preferably set to 15 degrees to 45 degrees, more preferably 25 degrees to 35 degrees. Here, the viewing angle is an angle (visible angle) through which light can pass, and in this embodiment, it is an angle through which light passes when the louver film 24 is viewed from the bottom 15 side. The narrower viewing angle increases the directivity of infrared light. In addition, since infrared light can reduce the influence of transmittance on various bottle colors, it becomes easier to recognize patterns in an image of the bottom portion 15 . If the viewing angle is less than 15 degrees, the image of the bottom part 15 other than the central part in the captured image becomes too dark and is not suitable for appearance inspection, and if it exceeds 45 degrees, the directivity is low and the outline of the pattern becomes unclear. .

The second illumination section 31 includes a second light source 32 and a light guide plate 34. The second illumination unit 31 is a planar surface light source extending on a plane orthogonal to the central axis 12 and emits diffused light from substantially the entire surface toward the bottom 15 of the glass bottle 10 . The second illumination unit 31 preferably has a substantially rectangular plate shape because it provides excellent uniformity of illumination, but the second illumination unit 31 is not limited to this and may have, for example, a disk shape. The second illumination unit 31 can employ a known illumination such as a flat dome (Japan registered trademark) illumination (International Publication No. WO2020/045557A1) manufactured by CCS Corporation. In order to transmit the infrared light from the first illumination unit 21 , the second illumination unit 31 has a flat light guide plate 34 arranged in the center and a second light source 32 arranged on the outer edge of the light guide plate 34 .

The second light source 32 is, for example, a plurality of LEDs (not shown) that emit visible light from the outer edge of the light guide plate 34 toward the center of the light guide plate 34 . For example, the LEDs are arranged side by side on the inner peripheral surface of the frame-shaped body surrounding the light guide plate 34 . An organic EL may be used instead of the LED. The second light source 32 is preferably visible light having a peak wavelength of 400 nm to 630 nm. In addition, the second light source 32 preferably includes a red LED with a peak wavelength of, for example, around 630 nm and a blue LED with a peak wavelength of around 470 nm. preferable. This is because the transmittance of light differs depending on the color of the bottle. It is preferable to apply a blue LED with high transmittance to a blue bottle.

The light guide plate 34 transmits infrared light from the first light source 22 while diffusing and emitting visible light incident from the second light source 32 on the outer edge from the surface on the bottom 15 side. A known plate can be used for the light guide plate 34 .

Visible light emitted from the second lighting unit 31 is polarized by the first circularly polarizing film 35 , passes through the bottom 15 , passes through the opening of the mouth 13 , passes through the second circularly polarizing film 36 , and reaches the camera 4 . is received by A first circular polarizing film 35 is arranged between the illumination device 2 and the bottom 15 . A second circularly polarizing film 36 is placed between the mouth 13 of the vial 10 and the camera 4 . The first circularly polarizing film 35 and the second circularly polarizing film 36 have basically the same shape, and are arranged in respective planes perpendicular to the center axis 12 near the mouth 13 and near the bottom 15 . The first circularly polarizing film 35 is arranged with a predetermined distance D1 from the mounting table 60 . A distance D1 between the first circularly polarizing film 35 and the mounting table 60 is preferably 20 mm to 40 mm, for example, 30 mm. The first circularly polarizing film 35 and the second circularly polarizing film 36 have the same polarization direction. The polarization direction can be either clockwise or counterclockwise with respect to the direction along the central axis 12 . For example, the first circularly polarizing film 35 and the second circularly polarizing film 36 can both employ right-handed circularly polarized waves whose polarization directions are, for example, right-handed rotation directions, or both can employ left-handed circularly polarized waves. good. Both the first circularly polarizing film 35 and the second circularly polarizing film 36 can be configured by laminating a linear polarizing plate and a quarter-wave plate. When the diffused visible light from the second lighting unit 31 is converted into a linearly polarized wave by the first circularly polarizing film 35 and the second circularly polarizing film 36 and is received by the camera 4, defects such as foreign matter and foreign glass on the bottom 15 are eliminated. It can be recognized as a black part (a dark part with low brightness) in the captured image. In addition, since the first circularly polarizing film 35 and the second circularly polarizing film 36 do not polarize the infrared light, the infrared light of the first illumination section 21 is not affected.

The camera 4 is placed across the glass bottle 10 with respect to the illumination device 2 and captures an image of the bottom 15 . The camera 4 includes a first light receiving section 41 that detects only infrared light and a second light receiving section 42 that detects only visible light. The camera 4 separates the light incident from the mouth 13 side through the lens 45 into infrared light and visible light, and receives the light with the first light receiving section 41 and the second light receiving section 42 . The focal length of the lens 45 can be set so that the optical axis is on the central axis 12 and the image of the bottom 15 can be photographed.

The camera 4 can be equipped with a beam splitter 44 that separates infrared light and visible light. The beam splitter 44 is an optical component that splits incident light from the lens 45 into infrared light and visible light. As the beam splitter 44, a known one can be adopted, and it may be a cube type combining two prisms, or a plate type in which an optical thin film for spectroscopy is vapor-deposited on a thin plate glass. . In the example of FIG. 1, the beam splitter 44 reflects the infrared light of the incident light to the first light receiving section 41 located at a position of 90 degrees with respect to the central axis 12 , and transmits the visible light to the central axis 12 . The second light receiving portion 42 on the center axis 12 receives the light. In the image captured by the first light receiving unit 41, the outline of the pattern formed by the concave-convex engraving formed on the surface of the bottom part 15 appears in a dark color. The image captured by the second light receiving unit 42 has no difference in brightness due to the pattern, and defects appear in dark colors.

The first light-receiving unit 41 and the second light-receiving unit 42 are separate solid-state imaging devices, and for example, a CCD image sensor or a CMOS image sensor can be used, preferably a CMOS image sensor. By providing two light receiving units, it is possible to set each sensor to an appropriate camera gain and shutter speed, and to adjust the brightness of each image. In addition, since the image of the bottom portion 15 using infrared light and the image of the bottom portion 15 using visible light can be obtained simultaneously by a single bottom portion inspection apparatus 1, inspection efficiency can be improved and space can be saved. It is preferable that the first light receiving section 41 and the second light receiving section 42 have a light receiving sensitivity of 0% for a wavelength between infrared light and visible light, for example, 650 nm to 790 nm.

The control unit 50 is electrically connected to the lighting device 2 and the camera 4, executes, for example, processing related to turning on/off the lighting device 2 and processing related to photographing by the camera 4, and performs processing related to inspection using the photographed image. Execute. The control unit 50 may further execute processing related to the operation of a loading/unloading mechanism (not shown) for the glass bottle 10 . The control unit 50 includes, for example, processors such as CPU (Central Processing Unit) and GPU (Graphics Processing Unit), HDD (Hard Disk Drive), SSD (Solid State Drive), ROM (Read-Only Memory), RAM (Random Access s memory), input devices such as a keyboard, mouse, and touch pad, display devices such as a liquid crystal display and an organic EL (Electro Luminescence) display, digital input/output boards such as an I/O board, and the like. The CPU, storage device, etc. of the control unit 50 may be not only one but also a plurality of physically separated devices, in which case they may be connected via a communication network.

The control unit 50 has a determination unit 52 , an image processing unit 53 , a reading unit 54 and a storage unit 55 . A determination unit 52 determines whether or not there is a defect based on the image acquired from the camera 4 . Defects determined by the determining unit 52 include, for example, foreign matter on the inner surface of the bottom portion 15, conjugating foreign matter on the bottom portion 15, foreign glass on the bottom portion 15, and other defects during glass bottle molding. The control unit 50 can output the determination result of the determination unit 52 to the outside for each glass bottle 10. For example, even if the glass bottle 10 determined to have a defect is removed by a discharge unit (not shown) of the bottom inspection device 1 good. A part of the processing part of the control part 50 may execute processing by a device other than the control part 50. For example, a part of the processing of the image processing part 53 and the reading part 54 may be executed by the CPU provided in the camera 4. You may Specific processing in each section of the control section 50 will be described in "2. Bottom Inspection Method" below.

2. 1. Bottom Inspection Method An example of a bottom inspection method for glass bottles 10 according to the present embodiment using a bottom inspection apparatus 1 will be described in detail with reference to FIGS. 1 to 6. FIG. FIG. 3 is a flowchart of an inspection method using the bottom inspection apparatus 1, FIG. 4 is an example of the first image 101, FIG. 5 is an example of the second image 102, and FIG. It is a figure explaining a setting process (S40).

As shown in FIG. 3, the bottom inspection method according to the present embodiment is a bottom inspection method for a glass bottle 10 having an engraving on the surface of the bottom 15, and includes, for example, an imaging step (S10) and a pattern detection step (S20). ), a mask making step (S30), an inspection area setting step (S40), a detection step (S50), a determination step (S60), a non-defective product process (S70), and a defective product process. (S80) and. Each step will be described in order below with reference to FIGS. 1 and 2. FIG.

S10: The control unit 50 executes shooting processing. Preferably, the control unit 50 executes the lighting process prior to S10. In the lighting process, the controller 50 outputs a signal for lighting the first lighting unit 21 and the second lighting unit 31 to the lighting device 2 . In the photographing process, the control unit 50 outputs a signal for executing photographing to the camera 4 and causes the camera 4 to transmit the photographed image data to the control unit 50 . The camera 4 shoots the first image 101 of the bottom 15 in FIG. The second image 102 of the bottom portion 15 in FIG. The control unit 50 can acquire each image data from the output from the camera 4 . The acquired image data may be stored in the storage unit 55 .

S20: The control unit 50 executes pattern detection processing. For example, in the pattern detection process, the determination unit 52 detects the pattern 70 emphasized with infrared light from the first image 101 acquired in S10. The determination unit 52 may detect the pattern 70 by, for example, "pattern search". The image processing section 53 may perform image pre-processing on the pattern 70 before S20 in order to more reliably detect the pattern 70 in the determination section 52 . Further, the reading unit 54 can read, for example, the model number from the pattern 70 detected in the first image 101 . Among the

patterns

70, 10 substantially elliptical codes arranged at intervals along a circular orbit correspond to model numbers as barcode-like codes called CID marks (see Japanese Patent Laid-Open No. 2001-270719). Since the code is assigned, the reading unit 54 can read the model number from the position and number of codes. Since the model number can be read with a single inspection device along with the judgment of the defect described later, efficient inspection can be performed in a small space.

A first image 101 shown in FIG. 4 is an image captured by the first light receiving unit 41 . In the first image 101, the contours of the plurality of patterns 70 derived from the engraving of the bottom portion 15 and the foreign matter (detection object 72) appear as dark shadows. The plurality of patterns 70 include, for example, knurling along the outer edge of the bottom portion 15, a company mark indicating the manufacturing site of the glass bottle 10, a mold number, a CID mark, and the like. These patterns 70 are derived from engravings carved into the mold, and thus have regularity in advance. It is desirable to store the pattern of the pattern 70 based on this regularity in advance in the storage unit 55 . Then, if the pattern 70 can be detected from the first image 101, for example, from the position and shape of the outer edge of the bottom portion 15, the position of the outer edge to the center position of the bottom portion 15, the distance from the center position to each pattern 70, the shape and arrangement, etc. The rotation angle and the like about the center axis 12 of the bottom 15 can be estimated.

For image preprocessing, for example, "blurring processing" can be performed in order to perform "pattern search" by the determination unit 52. The “blurring process” can be performed, for example, by an averaging filter, which is a two-dimensional filter that replaces the pixel value of the pixel of interest with the average value of all pixel values within the filter size range and outputs the result. Further, as another image preprocessing, for example, "dilation processing" that dilates black shadows may be employed.

The determination unit 52 performs pattern detection processing on the first image 101 on which image preprocessing has been performed, for example. In the pattern detection process, the determination unit 52 detects the pattern 70 by performing a pattern search on the first image 101 using a pattern registration image created in advance based on the outer shape of the engraving on the bottom 15 . In the pattern search, the first image 101 is searched for a detection object that matches the pattern registration image, and the detection object is detected as the pattern 70 when the pattern registration image matches the outline of the pattern 70 to a certain extent. In the first image 101, since the outline of the pattern 70 is emphasized by highly directional infrared light, detection accuracy by pattern search is high. has regularity, the position of the pattern 70 can be detected with high accuracy.

S30: The control unit 50 executes the mask creation process. For example, in the mask creation step, the image processing unit 53 creates a mask based on the first image 101 (FIG. 4) from which the pattern 70 is detected in S20, and arranges the mask 80 on the second image 102 (FIG. 5). (Fig. 6). The corresponding positional relationship between the first image 101 captured by the first light receiving unit 41 and the second image 102 captured by the second light receiving unit 42 is measured and adjusted in advance. If the positional information of 70 is known, the position where pattern 70 exists in second image 102 can be known. Therefore, the mask 80 is placed at the correct position in the second image 102 .

4 to 6, the mask creation process first includes a plurality of masks 80 (see FIG. 6) is created. As shown in FIG. 5, in the second image 102 captured by the second light receiving unit 42, the detected object 72, which is a defect, can be recognized as a dark spot, but the pattern 70 is hardly recognizable. Next, based on the positional information of each pattern 70 in the first image 101 in FIG. 4, the mask 80 is placed on the second image 102 so as to cover each pattern 70 in the second image 102 in FIG. becomes a state like A part of the mask 80 may be created in advance according to the engraving (or pattern registration image) of the glass bottle 10 to be inspected and stored in the storage unit 55 . The size of each mask 80 may be substantially the same as that of each pattern 70, or may be a size sufficient to cover a plurality of patterns 70 in a single mask 80. FIG.

S40: The control unit 50 executes an inspection area setting step. For example, the inspection area setting step may be performed at the same time as S30, and one or more inspection gates 83 having a preset shape are created in the second image 102 based on the position of the pattern 70 detected by the pattern search. 53 places. Since the pattern 70 has regularity, the positions of the

inspection gates

82 and 83 can be determined by setting the relative positions of the pattern 70 and the inspection gates 83 in advance. can be automatically laid out on the second image 102 . The

inspection gates

82 , 83 can be set, for example, as one or more annular regions concentric with the central axis 12 at the bottom 15 . In FIG. 6, two

check gates

82, 83 are set. The inspection gate 82 and the inspection gate 83 can be set to have different sensitivities. You can set it to a higher sensitivity.

S50: The control unit 50 executes the detection process for each

inspection gate

82,83. For example, in the detection step, the mask 80 and the

inspection gates

82 and 83 are arranged in S30 in FIG. To detect. For dark portions in the second image 102 , the detection object 72 is detected by, for example, executing an inspection algorithm for each inspection gate 82 stored in advance in the storage unit 55 . The inspection algorithm includes, for example, a process of binarizing the illuminance data read to the

inspection gates

82 and 83 and detecting the detection object 72 in comparison with the surrounding pixels, and a process of detecting a small area within the

inspection gates

82 and 83. Examples include a process of creating a region (segment), moving this segment in the circumference or radial direction, calculating the average density, comparing the density difference, and detecting the detection object 72 . By excluding certain portions of mask 80 and executing the inspection algorithm on

inspection gates

82 and 83, high sensitivity inspection can be performed. When executing the inspection algorithm, the determination step (S60) may be executed at the same time.

S60: The control unit 50 executes the determination process. For example, in the determination step, it is determined whether or not the detection object 72 in the second image 102 detected in S50 is defective, and based on the result, it is determined whether or not the glass bottle 10 is a non-defective product. Reference data stored in the storage unit 55 in advance is used as the criterion. The criteria for determination include, for example, the area and shape of the detection body 72 . If the result of the determination step is that the detection body 72 is not a defect, the glass bottle 10 is regarded as a "non-defective product" and the control unit 50 executes S70. ”, the control unit 50 executes S80. Of course, if the detection object 72 itself is not detected in S50, S70 is executed assuming that the determination result is "non-defective".

S70: The control unit 50 executes the process of processing as a non-defective product. For example, in the process of processing as a non-defective product, the control unit 50 outputs a signal to a conveying means (not shown) to convey the glass bottle 10 to be inspected as a "non-defective product" to the next process.

S80: The control unit 50 executes the process of treating the product as defective. For example, in the step of treating the glass bottle 10 as a defective product, the model number is read from the pattern 70 detected in S20, and data in which the determination result and the model number are linked is stored in the storage unit 55, and the glass bottle 10 to be inspected is identified as "non-performing." The control unit 50 outputs a signal to discharge the product to a disposal unit (not shown) as a non-defective product. The “defective product” determination result and model number data stored in the storage unit 55 may be output from the control unit 50 to the glass bottle 10 manufacturing apparatus (not shown).

As described above, in the conventional inspection of the bottom portion 15, it is difficult to distinguish between the pattern 70 and the detection object 72 other than the pattern 70, but according to the present embodiment, the pattern 70 can be detected from the first image 101. Since it can be detected, it is easy to use the second image 102 to determine the presence or absence of the detection object 72 in the area (inspection gate 82 ) where there is no pattern 70 .

3. Modification An example of using the bottom inspection apparatus 1 for the bottom inspection method of the glass bottle 10 according to the modification will be described in detail with reference to FIG. 7 . FIG. 7 is an example of the third image 103. As shown in FIG. Since the modified example is basically the same as "2. Bottom part inspection method", redundant description will be omitted.

A third image 103 shown in FIG. 7 is an image of the bottom portion 15 of the glass bottle 10 whose body portion 14 has a square cross-section and is captured by the second light receiving unit 42 . A plurality of masks 80 are arranged for each pattern, and an inspection gate 82 matching the outer edge (rectangular shape) of the trunk portion 14 is set outside the knurling that serves as the ground surface of the bottom portion 15 . Since the pattern of the bottom part 15 and the orientation (rotational angle) of the outer edge of the body part 14 correspond to each other, the rectangular inspection gate 82 can be provided in accordance with the orientation of the body part 14 by detecting the pattern in S20. This makes it possible to inspect areas outside the ground plane.

As Example 1, the bottom inspection device 1 shown in FIG. The camera 4 is a 2CMOS area sensor camera with 1.55 million pixels, the first circularly polarizing film 35 and the second circularly polarizing film 36 are both equal in the clockwise rotation direction, the distance D1 is 30 mm, and the first illumination unit 21 is a red light. It is external light diffusion lighting, and a cross louver film with a viewing angle of 30 degrees is arranged as the louver film 24 between the first lighting unit 21 and the second lighting unit 31, and the second lighting unit 31 has a visible light with a peak at 630 nm. It was an optical flat dome (registered trademark of Japan) illumination.

The upper stage of FIG. 8 is the first image captured by the first light receiving section 41 of the camera 4, and the lower stage of FIG. 8 is the second image captured by the second light receiving section 42. In the first image, the CID mark and the like can be clearly recognized, and in the second image, the foreign matter falling in the center can be clearly recognized as black, and the controller 50 determines that the product is "defective".

In addition, as Comparative Example 1, the glass bottle 10 was inspected after removing the first circularly polarizing film 35 and the second circularly polarizing film 36 from the same bottom inspection device 1 of FIG.

The upper stage of FIG. 9 is the first image captured by the first light receiving section 41 of the camera 4, and the lower stage of FIG. 9 is the second image captured by the second light receiving section 42. In the first image and the second image, the foreign matter dropped in the center could not be recognized, and the control unit 50 determined that the product was "non-defective".

The present invention is not limited to the above-described embodiments, and various modifications are possible, including substantially the same configurations as those described in the embodiments. Here, the "same configuration" means a configuration with the same function, method, and result, or a configuration with the same purpose and effect. Moreover, the present invention includes configurations in which non-essential portions of the configurations described in the embodiments are replaced. In addition, the present invention includes a configuration that achieves the same effects or achieves the same purpose as the configurations described in the embodiments. In addition, the present invention includes configurations obtained by adding known techniques to the configurations described in the embodiments.

DESCRIPTION OF SYMBOLS 1... Bottom inspection apparatus, 2... Lighting apparatus, 4... Camera, 10... Glass bottle, 12... Center axis line, 13... Mouth part, 14... Body part, 15... Bottom part, 21... 1st illumination part, 22... 1st Light source 23... Diffusion plate 24... Louver film 24a... Louver 24b... Light transmitting part 31... Second illumination part 32... Second light source 34... Light guide plate 35... First circularly polarizing film 36... Second circular polarizing film 41 First light receiving unit 42 Second light receiving unit 44 Beam splitter 45 Lens 50 Control unit 52 Determination unit 53 Image processing unit 54 Reading unit 55...storage part 60...mounting table 70...pattern 72...detection object 80...

mask

82, 83...inspection gate 101...first image 102...second image 103...third image D1... interval

Claims

a lighting device that irradiates light toward the bottom of the glass bottle;
a camera placed across the glass bottle with respect to the lighting device and capturing an image of the bottom;
a first circularly polarizing film disposed between the lighting device and the bottom;
a second circularly polarizing film disposed between the mouth of the glass bottle and the camera;
with
The lighting device includes a first lighting unit that emits infrared light having directivity toward the bottom, and a diffusing property toward the bottom that is disposed between the first lighting unit and the bottom. and a second illumination unit that emits visible light,
The camera includes a first light receiving unit that detects only infrared light and a second light receiving unit that detects only visible light,
The apparatus for inspecting the bottom of a glass bottle, wherein the first circularly polarizing film and the second circularly polarizing film have the same polarization direction.
In claim 1,
An apparatus for inspecting the bottom of a glass bottle, wherein the camera comprises a beam splitter for separating infrared light and visible light.
In claim 1 or claim 2,
The first illumination unit includes a first light source that emits diffuse infrared light, and a louver film having a plurality of louvers that limit the angle of transmission of the infrared light incident from the first light source. ,
The apparatus for inspecting the bottom of a glass bottle, wherein the louver film has a plurality of louvers extending in a grid pattern in a direction orthogonal to a central axis of the glass bottle.
In claim 3,
The apparatus for inspecting the bottom of a glass bottle, wherein the louver film has a viewing angle of 15 degrees to 45 degrees on the central axis.