JP7168215B2 - Article inspection device and article inspection method - Google Patents

Description

The present invention relates to an article inspection apparatus and article inspection method for inspecting the presence or absence or position of a light-transmitting resin member in an article made of a light-transmitting inorganic material.

For example, Patent Literature 1 discloses an article inspection device that inspects the pasting position of a label (an example of a resin member) attached to a glass bottle (an example of an article) using a first polarizing filter and a second polarizing filter. It is In this inspection device, the light emitted from the light source is passed through the first polarizing filter, then passed through the vicinity of the label upper edge of the glass bottle to which the label is pasted, and furthermore, the light oscillating in a direction substantially perpendicular to the first polarizing filter is passed through. Light other than the light that has passed through the label is cut by passing through the second polarizing filter. The direction of vibration of the light that passes through the transparent part of the label is rotated by 90°, so only the light that has passed through the transparent part of the label reaches the camera. to inspect.

However, if the resin member such as a label is made of an optically anisotropic resin material such as having a birefringence index, the angle at which the direction of vibration of the light passing through the transparent portion of the resin member rotates is 90°. However, it may change depending on the direction of the resin member (for example, the direction of the optical axis) and the type. If the vibration direction of the polarized light emitted from the light source that passes through the first polarizing filter does not match the orientation or type of the resin member, part or substantially all of the light that has passed through the resin member is cut by the second polarizing filter. and the accuracy of the inspection is greatly reduced.

Further, in Patent Document 2, the light emitted from the light source is linearly polarized by a polarizer, the linearly polarized light is passed through a transparent film, and the passing light is irradiated to an analyzer whose polarization direction is substantially orthogonal to the polarizer. Then, a transparent film detection device is disclosed in which an image sensor detects a change in the amount of light that has passed through an analyzer. In this device, when the type of transparent film is changed, the rotating means for rotating the polarizer and the analyzer while maintaining the polarization directions of the polarizer and the analyzer being substantially perpendicular to each other is driven, and the polarizer and the analyzer are incident on the transparent film. The polarization direction of the linearly polarized light can be adjusted to a position where it is optically rotated by a sufficiently large angle by the transparent film.

JP-A-2002-296009 JP-A-5-319680

However, even if the rotating means described in Patent Document 2 is provided, the rotating means is driven every time the orientation or type of the resin member such as a label attached to an article such as a glass bottle or a transparent film changes, and the polarizer and the like are changed. An adjustment operation is required to rotate the analyzer while maintaining a substantially orthogonal orientation. In addition, it is not possible to handle inspections in which articles such as labels with different orientations or different kinds of resin members are mixed in the inspection line. Therefore, there is a demand for an article inspection apparatus that can inspect the presence or absence or position of a resin member on an article regardless of the orientation or type of the resin member attached to the article.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an article inspection apparatus and an article inspection method capable of inspecting the presence or absence or position of a resin member on an article regardless of the orientation or type of the resin member attached to the article.

Means for solving the above problems and their effects will be described below.
An article inspection apparatus that solves the above problems is an article inspection that irradiates light onto an inspection target area of an article made of a light-transmitting inorganic material to inspect the presence or absence or position of a light-transmitting resin member attached to the article. An apparatus comprising a first light source, a first polarizer, and an analyzer, wherein light from the first light source passes through the first polarizer and irradiates a first polarized light onto an inspection target region of the article, a first image generating mechanism for generating a first image of the first polarized light transmitted through the article through the analyzer arranged such that the transmission axis crosses the transmission axis of the first polarizer; It has two light sources, a second polarizer, a phase shifter and an analyzer, and the light from the second light source is arranged in a direction such that the transmission axis is at a different angle with respect to the transmission axis of the first polarizer. A region to be inspected of the article is irradiated with the second polarized light that has passed through the second polarizer, and the second polarized light is passed through the phase shifter at least before and after passing through the article to obtain a phase difference of the second polarized light. is changed to rotate the vibration direction of the second polarized light by an angle corresponding to the predetermined angle formed by the transmission axes of the first polarizer and the second polarizer to obtain the third polarized light, and a second image generating mechanism that passes polarized light through the analyzer to generate a second image; an imaging unit that captures the first image and the second image; and an image captured by the imaging unit. and an inspection unit that inspects the presence or absence or position of the resin member based on.

According to this configuration, the first image generation mechanism and the second image generation mechanism irradiate the resin member in the inspection target area with two polarized light beams whose oscillation directions (polarization directions) differ by a predetermined angle. Therefore, the rotation angle of the vibration directions of the two polarized light beams passing through the resin member is large for one of the two polarized light beams and small for the other, regardless of the direction or type of the resin member. In the second image generation mechanism, the transmission axes of the second polarizer and the analyzer are not perpendicular to each other, but the vibration direction of the light is rotated by an angle corresponding to a predetermined angle through the phase shifter. Therefore, even if one of the two polarized lights transmitted through the resin member in the inspection target area is cut off by the analyzer, the other is transmitted through the analyzer. As a result, even if one of the first image and the second image has a dark resin member portion, the other has a bright resin member portion. Therefore, in captured images obtained by capturing the first image and the second image, the portion of the resin member always becomes a bright portion, and the portion other than the resin member becomes a dark portion. The inspection unit inspects the presence or absence or position of the resin member based on this captured image. Therefore, the presence or absence or position of the resin member on the article can be inspected regardless of the orientation or type of the resin member attached to the article.

In the above article inspection apparatus, the phase shifter has an angle (nπ−θ) corresponding to a predetermined angle θ between transmission axes of the first polarizer and the second polarizer (where n is 0 or more). It is preferable to change the phase difference by an amount capable of rotating the oscillation direction of the polarized light by (integer).

According to this configuration, the brightness of the resin member portion in the captured image can be increased regardless of the direction or type of the resin member attached to the article. Therefore, the presence or absence or position of the resin member on the article can be inspected with high accuracy regardless of the direction or type of the resin member attached to the article.

An article inspection apparatus that solves the above problems is an article inspection that irradiates light onto an inspection target area of an article made of a light-transmitting inorganic material to inspect the presence or absence or position of a light-transmitting resin member attached to the article. An apparatus comprising a first light source, a first polarizer, and a first analyzer, wherein light from the first light source passes through the first polarizer and irradiates a first polarized light onto an area to be inspected of the article. and a first image generator for generating a first image of the first polarized light transmitted through the article through the first analyzer oriented such that the transmission axis crosses the transmission axis of the first polarizer. a mechanism, a second light source, a second polarizer, and a second analyzer, wherein light from the second light source is oriented such that the transmission axis is at a different angle with respect to the transmission axis of the first polarizer; The inspection target area of the article is irradiated with the second polarized light that has passed through the second polarizer, and the second polarized light that has passed through the article is applied in a direction in which the transmission axis intersects the transmission axis of the second polarizer. a second image generation mechanism that generates a second image through the second analyzer arranged in the second image generation mechanism, an imaging unit that captures the first image and the second image, and the imaging unit acquires an inspection unit that inspects the presence or absence or position of the resin member based on the captured image.

According to this configuration, the first image generation mechanism and the second image generation mechanism irradiate the resin member in the inspection target area with two polarized light beams whose oscillation directions (polarization directions) differ by a predetermined angle. Therefore, the rotation angle of the vibration directions of the two polarized light beams passing through the resin member is large for one of the two polarized light beams and small for the other, regardless of the direction or type of the resin member. As a result, the first image and the second image have a relationship in which one of them has a dark resin member portion and the other has a bright resin member portion. Therefore, in captured images obtained by capturing the first image and the second image, the portion of the resin member always becomes a bright portion, and the portion other than the resin member becomes a dark portion. The inspection unit inspects the presence or absence or position of the resin member based on this captured image. Therefore, the presence or absence or position of the resin member on the article can be inspected regardless of the orientation or type of the resin member attached to the article.

The article inspection apparatus includes a drive control section that controls the image pickup section, and the drive control section causes the image pickup section to pick up the first image and the second image in one frame of image pickup operation. is preferred.

According to this configuration, since the image capturing unit captures the first image and the second image in one frame of image capturing operation, by processing one captured image, the direction or direction of the resin member attached to the article can be determined. The presence or absence or position of a resin member in an article can be inspected regardless of the type. Therefore, the inspection processing by the inspection unit can be simplified.

In the article inspection apparatus described above, it is preferable that the drive control section causes the first light source and the second light source to emit light at different timings within the same one-frame imaging period of the imaging section.
According to this configuration, the imaging unit captures the first image generated during the light emission period of the first light source and the second image generated during the light emission period of the second light source at different timings. Therefore, compared to a configuration in which these two images are captured at the same timing, the portion of the resin member in one captured image is brighter than the dark portion of the background including the portion of only the article other than the resin member. can be obtained as a part. As a result, the presence or absence or position of the resin member on the article can be inspected with high accuracy regardless of the direction or type of the resin member attached to the article.

In the article inspection device, it is preferable that the first light source and the second light source emit light at different timings, and the imaging section captures the first image and the second image in two separate and different frames. .

According to this configuration, the image capturing unit captures the first image and the second image in two different individual frames, so that the exposure time when capturing each frame can be easily adjusted, and the image including the first image can be captured. It is easy to obtain the first image and the second image including the second image with appropriate brightness or contrast. Further, if the imaging unit is configured to capture the first image and the second image in two frames, difference processing between frames becomes possible. If the difference between the two images is small, the detection accuracy can be improved by having the inspection unit take the difference between the frames. Therefore, the inspection section can inspect the presence or absence or position of the resin member on the article with high accuracy regardless of the orientation or type of the resin member attached to the article.

An article inspection method for solving the above problems is an article inspection for inspecting the presence or absence or position of a light-transmitting resin member attached to the article by irradiating light onto an inspection target area of an article made of a light-transmitting inorganic material. In the method, light from a first light source passes through a first polarizer and irradiates a region to be inspected of the article with the first polarized light, and the first polarized light that has passed through the article is applied to the transmission axis of the first polarizer. a first image generating step of generating a first image through an analyzer oriented with the transmission axis crossed with respect to the A region to be inspected of the article is irradiated with the second polarized light that has passed through the second polarizer arranged in the direction of the transmission axis of the angle, and the phase difference of the second polarized light is adjusted at least before and after passing through the article. changing the vibration direction of the second polarized light by an angle corresponding to a predetermined angle formed by the transmission axes of the first polarizer and the second polarizer to obtain the third polarized light; is passed through the analyzer to generate a second image, an imaging step of imaging the first image and the second image, and the captured image obtained in the imaging step and an inspection step of inspecting the presence or absence or position of the resin member based on the inspection.

According to this method, it is possible to obtain the same effect as that of the article inspection apparatus.
An article inspection method for solving the above problems is an article inspection for inspecting the presence or absence or position of a light-transmitting resin member attached to the article by irradiating light onto an inspection target area of an article made of a light-transmitting inorganic material. In the method, light from a first light source passes through a first polarizer and irradiates a region to be inspected of the article with the first polarized light, and the first polarized light that has passed through the article is applied to the first polarizer and the transmission axis. generating a first image through a first analyzer oriented in a crossed direction; and transmitting light from a second light source at different angles with respect to the transmission axis of the first polarizer. A region to be inspected of the article is irradiated with the second polarized light that has passed through a second polarizer arranged in an axial direction, and the second polarized light that has passed through the article is directed to the transmission axis of the second polarizer. a second image generating step of generating a second image through a second analyzer arranged in a direction in which the transmission axes intersect; an imaging step of imaging the first image and the second image; and an inspection step of inspecting the presence or absence or position of the resin member based on the captured image acquired by the unit.

According to this method, it is possible to obtain the same effect as that of the article inspection apparatus.

According to the present invention, the presence or absence or position of a resin member in an article can be inspected regardless of the orientation or type of the resin member attached to the article.

1 is a schematic side view showing a container inspection system provided with a container inspection device according to the first embodiment; FIG. FIG. 4 is a schematic side view showing a container to which a transparent resin member is attached; The schematic plan view which shows a container inspection apparatus. 4 is a flowchart showing container inspection processing; A timing chart showing control timings of a camera and two light sources. The figure explaining the image which a camera imaged the transparent resin member attached to the part without the liquid of a container. The figure explaining the image which a camera imaged the transparent resin member attached to the part with the liquid of a container. The schematic plan view which shows the container inspection apparatus in 2nd Embodiment.

(First embodiment)
A container inspection system including a container inspection device will be described below with reference to the drawings. As shown in FIG. 1, a container inspection system 11 includes a transport device 13 that transports a container 12, which is an example of an article to be inspected, and a container 12 that is transported in the transport direction X by the transport device 13 in the middle of a transport route. and a container inspection device 14 as an example of an article inspection device that inspects at the inspection position of . The conveying device 13 is constituted, for example, by a conveyor device 16 with a conveyor 15 . In the example shown in FIG. 2, the conveying device 13 includes a conveyor device 16A having a conveyor 15A that conveys the container 12 along a path passing through the inspection position, and a conveyor device 16B having a carrying-in conveyor 15 that transfers the container 12 to the conveyor 15A. and a conveyor device 16C having a conveyer 15 for carrying out which receives and conveys the inspected container 12 from the conveyor 15A. The conveying device 13 is not limited to the conveyor device 16, and may be a hanging conveying method in which the container 12 is conveyed in a suspended state by gripping or sucking it, or a screw conveying method in which the container is conveyed by rotation of a screw. In FIG. 1 , a width direction Y of the conveyor 15 is defined as a direction that intersects the two directions of the conveying direction X and the vertical direction Z. As shown in FIG.

In the inspection transportation area including the inspection position, the transportation device 13 transports the containers 12 one by one at a predetermined transportation speed with a predetermined interval formed by an interval forming device (not shown). The container inspection device 14 captures an image of the container 12 at an inspection position in the inspection transfer area with the camera 20 shown in FIG. The container inspection device 14 includes a sensor 17 that detects when the container 12 to be inspected approaches the inspection position shown in FIG. 1 by a predetermined distance. By controlling the camera 20 shown in FIG. 3 based on the detection signal from the sensor 17 detecting the container 12, the container 12 is imaged at the inspection position shown in FIG. 1, and the container 12 is inspected based on the captured image. .

As shown in FIG. 2, the container 12 is made of a light transmissive inorganic material. Specifically, the container 12 is made of a transparent or translucent glass bottle. A light-transmissive resin member 18 is attached to the container 12 . The resin member 18 has, for example, an annular shape, and is attached while being inserted into the neck or shoulder of the container 12 .

Here, the light-transmissive resin member 18 is made of a transparent or translucent synthetic resin. Examples of the resin member 18 include a piece of vinyl and a PET (polyethylene terephthalate) film. In addition to vinyl and PET, thermoplastic resins such as polyethylene (PE), polypropylene (PP), polystyrene, acrylic, and polyamide (nylon), and thermosetting resins such as melamine, unsaturated polyester, and epoxy may be used.

The resin member 18 is made of, for example, a film or sheet, and may be oriented due to manufacturing reasons such as stretching during the manufacturing process, exhibit anisotropy in optical properties, and have an optical axis. The resin member 18 shown in FIG. 2 is manufactured by cutting a resin film or a resin sheet. The angle at which the plane of polarization) rotates changes depending on the orientation of the resin member 18 (orientation of the optical axis). In other words, the direction of the optical axis of the resin member 18 when the angle of rotation of the vibration direction of the linearly polarized light passing through the resin member 18 is, for example, 90° may be the circumferential direction of the cylindrical shape. It may be widthwise. Furthermore, the orientation of the optical axis of the resin member 18 also changes depending on the orientation of the resin member 18 attached to the container 12 . Note that the container inspection device 14 uses an area including part or all of the resin member 18 in the container 12 shown in FIG. 2 as an inspection target area. The container inspection device 14 irradiates light onto an area including the inspection target region of the container 12, captures an image transmitted through the container 12 and the resin member 18 with a camera 20 (see FIG. 3), and based on the captured image, resin Existence or position of member 18 is inspected.

The container 12 may be liquid-filled or empty. In the example shown in FIG. 2, the lid 19 is provided while the container 12 is filled with liquid. The purpose for which the resin member 18 is attached to the container 12 may be anything, such as decoration/design of the container 12, advertising, quality display, and capacity display. For example, as a proof that the lid 19 is filled with liquid or that a portion of the container 12 including the lid 19 is covered and sealed with a sealing film (not shown). The resin member 18 may be attached.

In the example shown in FIG. 2, a resin member 18 is attached to the neck of the container 12 and positioned above the liquid surface LS of the liquid filled in the container 12 . 2, the resin member 18 may be attached to the shoulder of the container 12 and positioned below the liquid surface LS of the container 12. As shown in FIG. Alternatively, container 12 may be empty. For example, the presence or absence of the resin member 18 that should have been removed from the empty container 12 may be inspected.

In this embodiment, the container inspection device 14 shown in FIG. 1 inspects the presence or absence of the resin member 18 . As shown in FIG. 1, in the inspection of the container 12 to which the resin member 18 is attached, the container 12 is determined to be a non-defective product if the resin member 18 is present, and is determined to be defective if the resin member 18 is absent. In the inspection of the container 12 from which the resin member 18 has been removed, the container 12 is determined to be non-defective if the resin member 18 is not present, and the container 12 is determined to be defective if the resin member 18 is present. In this manner, the container inspection device 14 detects the presence or absence of the resin member 18 and inspects whether the container 12 is good or defective according to the detection result.

Next, the configuration of the container inspection device 14 will be described with reference to FIG.
As shown in FIG. 3, the container inspection device 14 includes a first light source 21, a second light source 22, a first polarizer 23, a second polarizer 24, an analyzer 25, and a wave plate 26 as an example of a phase shifter. Prepare. The first light source 21 irradiates a first area including the inspection target area of the container 12 at the inspection position with light. The second light source 22 irradiates the container 12 at the inspection position with light from a light irradiation direction different from the light irradiation direction of the first light source 21 to a second area including the inspection target region. In the example shown in FIG. 3, the first light source 21 and the second light source 22 are different from each other in that the angles formed by the optical axes of the first light source 21 and the second light source 22 are predetermined angles within the range of 60° or more and 150° or less. placed in the direction. The inspection target area irradiated with the light of the first light source 21 and the inspection target area irradiated with the light of the second light source 22 are basically at the same position, but both positions may be shifted. .

Further, as shown in FIG. 3, the container inspection apparatus 14 transmits the light from the first light source 21 through the inspection target area of the container 12 to generate a first image Img1 (see FIGS. 6 and 7). A first image-generating mechanism 31 and a second image-generating mechanism that generates a second image Img2 (see FIGS. 6 and 7) by transmitting light from a second light source 22 to an inspection target area of the container 12. 32. Further, the container inspection device 14 includes a camera 20 that captures the first image Img1 and the second image Img2, and a controller 50 that controls the first light source 21, the second light source 22, and the camera 20.

As shown in FIG. 3, the first image generating mechanism 31 comprises a first light source 21, a first polarizer 23, an analyzer 25, a first mirror 33 and a second mirror . The second image generation mechanism 32 also includes a second light source 22 , a second polarizer 24 , an analyzer 25 , a wavelength plate 26 , a third mirror 35 and a fourth mirror 36 .

As shown in FIG. 3, the first polarizer 23 is positioned between the first light source 21 and the container 12 in the inspection position. The first polarized light L1 that has passed through the first polarizer 23 is applied to the first area including the inspection target area of the container 12 . The first polarized light L1 transmitted through the container 12 and the resin member 18 is reflected by the first mirror 33, and the reflected first polarized light L1 is further reflected by the second mirror 34, then transmitted through the analyzer 25, and transmitted to the first polarized light L1. generates an image Img1 of The first mirror 33 is arranged to face the first polarizer 23 with the container 12 at the inspection position interposed therebetween. reflect towards. The second mirror 34 reflects the first polarized light L<b>1 incident from the first mirror 33 toward the analyzer 25 . The analyzer 25 outputs the first image Img1 toward the camera 20 by transmitting the first polarized light L1 from the second mirror 34 .

As shown in FIG. 3, the second polarizer 24 is positioned between the second light source 22 and the container 12 in the inspection position. The second polarized light L2 obtained by passing the light of the second light source 22 through the second polarizer 24 is irradiated onto the second area including the inspection target area of the container 12 from a light irradiation direction different from that of the first polarized light L1. The second polarized light L2 that has passed through the container 12 and the resin member 18 becomes third polarized light L3 that has a phase difference different from that of the second polarized light L2 by passing through the wavelength plate 26 .

The wavelength plate 26 has a function of changing the phase difference of incident light during the transmission process and emitting the light. Wave plate 26 rotates the vibration direction of the polarized light transmitted through resin member 18 in the area to be inspected by an angle corresponding to the predetermined angle formed by transmission axes 23A and 24A of first polarizer 23 and second polarizer 24, respectively. The phase difference of the second polarized light L2 is changed by the phase difference Φ to be the third polarized light L3. The third polarized light L3 is reflected by the third mirror 35, and the reflected third polarized light L3 is further reflected by the fourth mirror 36 and then transmitted through the analyzer 25 to generate the second image Img2.

The third mirror 35 is arranged at a position facing the second polarizer 24 with the container 12 at the inspection position in between. is reflected toward the fourth mirror 36 . The fourth mirror 36 reflects the third polarized light L3 incident from the third mirror 35 toward the analyzer 25 . The analyzer 25 outputs the second image Img2 toward the camera 20 by transmitting the third polarized light L3 reflected by the fourth mirror 36 . Here, in the process of transmitting the second polarized light L2 through the wavelength plate 26, it becomes the third polarized light L3 whose phase difference has been changed.

The first polarizer 23, the second polarizer 24, and the analyzer 25 are each composed of a polarizing plate (for example, a polarizing filter). In FIG. 3, the directions of the respective transmission axes 23A, 24A and 25A are indicated by the directions of a plurality of parallel lines drawn in circles near the polarizers 23, 24 and the analyzer 25, respectively. The directions of the transmission axes 23A and 24A of the first polarizer 23 and the second polarizer 24 are different by a predetermined angle θ. The predetermined angle θ is set to 45° in the example shown in FIG. The predetermined angle θ is preferably an angle within the range of 15° or more and 75° or less. It has been confirmed that if the predetermined angle θ is within this range, the presence or absence of the resin member 18 in the container 12 can be inspected. Note that the predetermined angle θ may be a value outside the above range as long as the presence or absence of the resin member 18 can be inspected.

Here, assuming that the horizontal direction parallel to the transport direction X is 0°, the transmission axis 24A is 0°, and the transmission axis 23A is inclined by a predetermined angle θ (45° in the example of FIG. 3) with respect to the horizontal (0°). ing. Assuming that the counterclockwise direction is the positive direction when viewed from the light propagating direction, the transmission axis 23A is rotated by a predetermined angle θ from 0° in the positive direction.

As shown in FIG. 3, the transmission axes 23A and 25A of the first polarizer 23 and the analyzer 25 intersect each other. In this example, the transmission axes 23A and 25A are orthogonal to each other. Here, the transmission axes 23A and 25A being “perpendicular” is not limited to 90°, but may be an angle A within the range of 80° to 100°. It's okay. In this example, as shown in FIG. 3, the angle A is 90 degrees as an example.

Further, as shown in FIG. 3, the transmission axes 24A and 25A of the second polarizer 24 and the analyzer 25 are not perpendicular to each other. In other words, the transmission axes 24A and 25A are in a relationship of directions forming an angle other than the angle A. As shown in FIG. In the example shown in FIG. 3, the transmission axes 24A and 25A are in a relationship of forming an angle of 45°. The transmission axes 23A and 25A of the first polarizer 23 and the analyzer 25 are orthogonal to each other, and the transmission axes 23A and 24A of the first polarizer 23 and the second polarizer 24 are set to form a predetermined angle θ. due to Therefore, the transmission axes 24A and 25A of the second polarizer 24 and the analyzer 25 are deviated from orthogonality (angle A) by an angle -θ corresponding to the predetermined angle θ. That is, the transmission axis 25A is tilted in the opposite direction (negative direction) with respect to the transmission axis 24A (0°) by a predetermined angle θ (for example, 45°) at which the transmission axis 23A is inclined at an angle of -θ. (eg -45°).

For this reason, the second imaging mechanism 32 comprises a wave plate 26 at a position on the optical path between the second polarizer 24 and the analyzer 25 . In this example, the wave plate 26 is arranged at a position between the container 12 at the inspection position and the third mirror 35 . Wave plate 26 has an angle (nπ-θ) (where n is an integer of 0 or more) corresponding to a predetermined angle θ formed by transmission axes 23A and 24A of first polarizer 23 and second polarizer 24, respectively. The phase difference of the second polarized light L2 is changed by the phase difference Φ that can rotate the vibration direction of the light. The wave plate 26 of this example changes the phase difference of the second polarized light L2 by the phase difference Φ that can rotate the vibration direction of the light by the angle (−θ). Then, when the second polarized light L2 passes through the wavelength plate 26, the phase difference of the second polarized light L2 is changed by the phase difference Φ, and becomes the third polarized light L3 whose oscillation direction is rotated by the angle -θ. As a result, an effect equivalent to that obtained by making the transmission axes 24A and 25A of the second polarizer 24 and the analyzer 25 substantially perpendicular to each other can be obtained. Here, the angle (nπ−θ) corresponding to the predetermined angle θ is not limited to being exactly (nπ−θ), and may be in the range of (nπ−θ)±10°, and inspection is possible. A value outside the range of (nπ−θ)±10° may be used as long as it is not limited. The wavelength plate 26 may be arranged between the second polarizer 24 and the container 12 at the inspection position instead of the position between the container 12 at the inspection position and the third mirror 35 . In this case, the third polarized light L3 after passing through the wave plate 26 is transmitted through the container 12 and the resin member 18 .

Also, the camera 20, the first light source 21, the second light source 22, and the sensor 17 are electrically connected to the controller 50 shown in FIG. The control unit 50 also includes a memory 51 that stores a program PR shown in the flowchart of FIG. The control unit 50 includes, for example, a CPU, and executes a program PR by the CPU to perform container inspection processing including light emission control of the light sources 21 and 22 and imaging control of the camera 20 . The control unit 50 includes a drive control unit 52 that controls the first light source 21 , the second light source 22 and the camera 20 , and an inspection unit 53 that inspects the presence or absence or position of the resin member 18 in the container 12 . In this example, the drive control unit 52 is configured by a CPU that executes the processes of steps S11 to S15 in FIG. Also, the inspection unit 53 is configured by a CPU that executes the processes of steps S16 to S18.

FIG. 5 shows control timings of the camera 20, the first light source 21, and the second light source 22 controlled by the control unit 50. FIG. As shown in FIG. 5, the first light source 21 and the second light source 22 are caused to emit light at different emission timings within the same one-frame imaging period IP during which the camera 20 performs one-time exposure and one-frame imaging operation. . That is, within the same one-frame imaging period IP, the first light emission that causes the first light source 21 to emit light, and the second light emission that causes the second light source 22 to emit light at a light emission timing different from that of the first light emission after the first light emission. conduct. The first light emission and the second light emission have different light emission timings and do not have overlapping periods. The camera 20 incorporates an imaging device made up of an area sensor. The imaging device in the camera 20 receives the first image Img1 generated by the first image generation mechanism 31 during the first light emission period and the second image Img1 during the second light emission period within the same one-frame imaging period IP. receives the second image Img2 generated by the image generating mechanism 32 of the . As a result, the first image Img1 and the second image Img2 are captured together in one frame imaging operation.

Here, FIGS. 6 and 7 show the first image Img1, the second image Img2, and the captured image Img3. FIG. 6 shows an example in which a resin member 18 is attached to a portion of the container 12 without liquid, and FIG. 7 shows an example in which a resin member 18 is attached to a portion of the container 12 with liquid. In the examples of FIGS. 6 and 7, the first polarized light L1 having an angle of "0°" between the horizontal direction of the container 12 and the vibration direction of the linearly polarized light generated through the first polarizer 23 is In the process of passing through the resin member 18 oriented in this direction, the vibration direction of the light does not rotate or the amount of rotation is small, and a considerable portion of the light is blocked by the analyzer 25 . Therefore, in the first image Img1, the resin member 18 in the direction shown in FIGS. 6 and 7 becomes a dark portion with low brightness. Further, in the examples of FIGS. 6 and 7, the second polarized light has an angle of "45°" between the horizontal direction of the container 12 and the vibration direction of the linearly polarized light generated by passing through the second polarizer 24. In the process of transmitting the resin member 18 oriented in this direction, the vibration direction of the light is rotated by 90°, for example, and a considerable part of the third polarized light L3 that has passed through the wave plate 26 is transmitted to the analyzer 25 . Therefore, in the second image Img2, the resin member 18 in the direction shown in FIGS. 6 and 7 becomes a bright portion with high brightness.

Further, when the rotation direction of the resin member 18 is tilted by 45° with respect to the directions shown in FIGS. The portion of the member 18 becomes a bright portion with high brightness, and the portion of the resin member 18 becomes a dark portion with low brightness in the second image Img2. Then, even if the resin member 18 is oriented as shown in FIGS. 6 and 7, or inclined 45° from this, or oriented in a range between these orientations, the captured image Img3 Then, the portion of the resin member 18 becomes a bright portion with high brightness, and the background portion including only the portion of the container 12 other than the resin member 18 becomes a dark portion with low brightness. 6 and 7, both when the resin member 18 is attached to the portion of the container 12 without liquid (FIG. 6) and when the resin member 18 is attached to the portion of the container 12 with liquid, In both cases (FIG. 7), the portion of the resin member 18 in the captured image Img3 has the brightness, and the portion of the background thereof has the dark portion.

Next, operation of the container inspection system 11 will be described with reference to FIGS. 1 to 7. FIG.
When the operation of the container inspection system 11 shown in FIG. 1 is started, the conveyor device 16 is driven to convey the container 12 on the conveyor 15 . The containers 12 are transported one by one through the inspection transport area, and the container inspection device 14 inspects the presence or absence of the resin member 18 in the containers 12 at inspection positions along the way. The control unit 50 executes a program PR shown in the flow chart of FIG. Hereinafter, container inspection processing performed by the control unit 50 will be described with reference to FIG. 4 .

First, in step S11, the controller 50 determines whether or not the container 12 has been detected. If the sensor 17 detects the container 12, the control unit 50 proceeds to step S12, and if the sensor 17 does not detect the container 12, it waits until it detects it.

In step S<b>12 , the control unit 50 starts imaging with the camera 20 . That is, as shown in FIG. 5, exposure of the camera 20 is started.
In step S13, the controller 50 causes the first light source 21 to emit light. That is, as shown in FIG. 5, the first light emission is performed. When the first light source 21 emits light, in the first image generation mechanism 31, the light from the first light source 21 passes through the first polarizer 23, and the first polarized light L1 is irradiated onto the first area including the inspection target region of the container 12. The first polarized light L1 transmitted through the container 12 and the resin member 18 is sequentially reflected by the plurality of mirrors 33 and 34, and then passes through the analyzer 25 to generate the first image Img1. The first image Img1 is formed on the imaging surface of the imaging element of the camera 20 and received by the imaging element.

In the next step S14, the controller 50 causes the second light source 22 to emit light. The control unit 50 causes the first light source 21 and the second light source 22 to emit light at different emission timings. When the second light source 22 emits light, in the second image generating mechanism 32, the light from the second light source 22 passes through the second polarizer 24 to irradiate the second area including the inspection target area of the container 12 with the second polarized light L2. Then, the second polarized light L2 transmitted through the container 12 and the resin member 18 is transmitted through the wavelength plate 26 to generate the third polarized light L3 having a phase difference different from that of the second polarized light L2. That is, the third polarized light L3 is generated by changing the phase difference of the second polarized light L2 by the phase difference Φ by which the oscillation direction of the second polarized light L2 can be rotated by an angle of -θ. . After the third polarized light L3 is sequentially reflected by the plurality of mirrors 35 and 36, it passes through the analyzer 25 to generate the second image Img2. The second image Img2 is formed on the imaging surface of the imaging element of the camera 20 and received by the imaging element.

In step S<b>15 , the control unit 50 terminates imaging by the camera 20 . That is, the control unit 50 ends exposure of the camera 20 . In this way, the imaging element made up of an area sensor in the camera 20 receives the first image Img1 during the first light emission period, and receives the second image Img2 during the second light emission period. (See also FIGS. 6 and 7). At this time, even if the resin member 18 is attached to the portion of the container 12 where there is no liquid (FIG. 6) or the resin member 18 is attached to the portion of the container 12 with the liquid (FIG. 7), the captured image Img3 The portion of the resin member 18 inside is white with high brightness, and the background portion including the container 12 in the light irradiation area other than the resin member 18 is dark gray or black with low brightness. The processing of steps S11 to S15 is performed by the drive control section 52 of the control section 50. FIG.

In step S16 shown in FIG. 4, the control unit 50 performs image processing on the captured image Img3. Image processing includes, for example, binarization processing. The control unit 50 performs binarization processing on the captured image Img3 using a brightness threshold value, thereby separating areas of the high-brightness resin member 18 having brightness higher than the threshold value in the captured image Img3 from other areas.

At step S<b>17 , the control unit 50 determines whether or not the resin member 18 is present. That is, the control unit 50 obtains the shape and area of the separated region of the high-brightness resin member 18, compares the obtained shape and area with the shape threshold value and the area threshold value, respectively, and determines the shape and area of the resin member 18 based on the comparison result. Determine presence/absence. For example, when the determined shape exceeds the shape threshold and the determined area exceeds the area threshold, it is determined that there is a resin member. On the other hand, the control unit 50 determines that there is no resin member if either one of the determined shape and area does not exceed the threshold. The determination parameter used to determine whether or not the resin member 18 is present may be either the shape or the area.

At step S18, the controller 50 determines whether the container 12 is defective. Here, the processing for determining defective products is determined according to the definition of defective products. Definitions of defective products include: First, if the resin member 18 is not attached, the container 12 is regarded as a defective product due to mounting error. Secondly, if the resin member 18 is attached, the container 12 is regarded as a defective product due to mis-removal. Thirdly, if the adhering position of the resin member 18 deviates from the normal position by more than an allowable amount, the container 12 is regarded as a defective product due to misalignment. Regarding the first and second items, if the presence or absence of the resin member 18 is known, it is possible to determine whether the product is defective.

Therefore, in the third example, in step S17, the position of the resin member 18 in the container 12 is further detected when it is determined that the resin member 18 is present, in addition to determining whether or not the resin member 18 is present. For example, if the resin member 18 is a label attached to the container 12, positional deviation of the label on the container 12 is detected. Since the conveying height of the container 12 and the imaging height of the camera 20 are known, the detected position of the resin member 18 is within the normal label height range assumed from the conveying height of the container 12 in the vertical direction Z. If the label is deviated beyond the capacity, the control unit 50 determines that the label is misaligned.

Furthermore, in the first to third examples, the shape of the resin member 18 may be detected. For example, the control unit 50 acquires the shape and area from the region of the resin member 18 acquired by image processing of the captured image Img3, compares the shape and area with the shape threshold and the area threshold, and determines the shape and area. deviates from each threshold range by an allowable amount, it is determined that the label is defective in shape such as tearing or peeling of the label. In this manner, the control unit 50 determines that the container 12 is defective according to the presence or absence of the resin member 18, and if the resin member 18 is present, the container 12 is determined to be defective. For example, the container 12 is determined to be defective. The label may be, for example, a shrink label in which a cylindrical film made of a thermosetting resin is attached to the container 12 such as a glass bottle and then heat-shrunk to adhere to the outer peripheral surface of the container 12. , may be attached to the outer peripheral surface of the container 12 with an adhesive.

At step S19, the controller 50 discharges the container 12 as a defective product. The control unit 50 drives a discharge pusher or an air ejection device disposed on the side of the conveyor 15 at a position downstream of the inspection position in the conveying direction X to push out the defective container 12 or eject the defective container 12 by ejecting air. Remove from the conveyor 15.

As described in detail above, according to the first embodiment, the following effects are obtained.
(1) The container inspection device 14 irradiates light onto an inspection area of the container 12 made of a light-transmitting inorganic material to inspect the presence or position of the light-transmitting resin member 18 attached to the container 12 . The container inspection device 14 includes a first image generation mechanism 31 having a first light source 21, a first polarizer 23 and an analyzer 25, a second light source 22, a second polarizer 24, and a wavelength shifter as an example. a second imaging mechanism 32 having a plate 26 and an analyzer 25; The first image generation mechanism 31 irradiates the inspection target area of the container 12 with the first polarized light L1, which is the light from the first light source 21 that has passed through the first polarizer 23, and transmits the first polarized light L1 transmitted through the container 12. A first image Img1 is generated through an analyzer 25 arranged such that the transmission axis 25A intersects the transmission axis 23A of the first polarizer 23. FIG. The second image generating mechanism 32 passes the light from the second light source 22 through the second polarizer 24 oriented such that the transmission axis 24A is at a different angle with respect to the transmission axis 23A of the first polarizer 23 . A region to be inspected of the container 12 is irradiated with the two polarized lights L2. At least one of before and after the second polarized light L2 is transmitted through the container 12, the second polarized light L2 is passed through the wave plate 26 located on the optical path between the second polarizer 24 and the analyzer 25, and the second polarized light L2 is The oscillation direction of L2 is rotated by an angle (eg, −θ) corresponding to a predetermined angle θ formed by the transmission axes 23A and 24A of the first polarizer 23 and the second polarizer 24, respectively, to obtain the third polarized light L3. Then, the third polarized light L3 is passed through the analyzer 25 to generate the second image Img2. Further, the container inspection device 14 includes a camera 20 that captures the first image Img1 and the second image Img2, and an inspection unit that inspects the presence or absence or position of the resin member 18 based on the captured image Img3 acquired by the camera 20. 53.

The first image generation mechanism 31 and the second image generation mechanism 32 irradiate the resin member 18 in the inspection target area with two polarized light beams L1 and L2 in which the vibration directions (polarization planes) of the light differ by a predetermined angle θ. be done. Therefore, regardless of the orientation or type of the resin member 18, the rotation angle of the vibration directions of the two polarized light beams L1 and L2 transmitted through the resin member 18 is large for one of the two polarized light beams L1 and L2 and small for the other. . In the second image generating mechanism 32, the transmission axes 24A and 25A of the second polarizer 24 and the analyzer 25 are not perpendicular to each other. ° to 75°). Therefore, even if one of the two polarized lights L1 and L2 transmitted through the resin member 18 in the inspection target area is cut by the analyzer 25, the other is transmitted through the analyzer 25. FIG. As a result, even if one of the first image Img1 and the second image Img2 is dark at the resin member 18 portion, the other is bright at the resin member 18 portion. Therefore, in a captured image Img3 obtained by capturing the first image Img1 and the second image Img2, the portion of the resin member 18 is always a bright portion and the portion other than the resin member 18 is a dark portion. The inspection unit 53 inspects the presence or absence or position of the resin member 18 based on the captured image Img3. Therefore, the presence or absence or position of the resin member 18 in the container 12 can be inspected regardless of the orientation or type of the resin member 18 attached to the container 12 . Furthermore, since the common camera 20 captures the first image Img1 and the second image Img2, only one camera 20 is required. Also, the analyzer 25 is a common component of the first image generation mechanism 31 and the second image generation mechanism 32 . Therefore, the number of parts of the container inspection device 14 can be reduced, and the size of the device can be reduced.

(2) Since the container inspection device 14 does not need the rotation means of the inspection device described in Patent Document 2, the rotation means is driven every time the orientation or the type of the resin member attached to the article changes, and the polarized light is polarized. This eliminates the need for an adjustment operation to rotate the element and the analyzer while maintaining the substantially orthogonal relationship. In addition, it is possible to cope with an inspection in which containers 12 having resin members 18 of different orientations or different types are transported together on an inspection line such as the conveyor 15 of the container inspection system 11 .

(3) The wavelength plate 26 has an angle (nπ-θ) corresponding to a predetermined angle θ between the transmission axes 23A and 24A of the first polarizer 23 and the second polarizer 24 (where n is an integer of 0 or more). ) to change the phase difference Φ by the amount that can rotate the oscillation direction of the polarized light. Therefore, regardless of the orientation or type of the resin member 18 attached to the container 12, the brightness of the portion of the resin member 18 in the captured image Img3 can be increased. Therefore, the presence or absence or position of the resin member 18 in the container 12 can be inspected with high accuracy regardless of the direction or type of the resin member 18 attached to the container 12 .

(4) The container inspection device 14 includes a drive control section 52 that controls the camera 20 . The drive control unit 52 causes the camera 20 to capture the first image Img1 and the second image Img2 in one frame of imaging operation. Therefore, regardless of the orientation of the optical axis of the resin member 18 attached to the container 12, the presence or absence or the position of the resin member 18 in the container 12 can be inspected from one captured image Img3 captured by the camera 20. Therefore, the inspection process by the control unit 50 can be simplified.

(5) The drive control unit 52 causes the first light source 21 and the second light source 22 to emit light at different timings within the same one-frame imaging period IP of the camera 20 . Therefore, the first image Img1 generated during the first light emission period of the first light source 21 and the second image Img2 generated during the second light emission period of the second light source 22 are captured by the camera 20 at different timings. be done. Therefore, compared to a configuration in which the two images Img1 and Img2 are captured at the same timing by causing the two light sources 21 and 22 to emit light at the same timing, the resin member 18 portion in one captured image Img3 is replaced by the container 12. It can be obtained as a bright part with high brightness against the dark part of the background including the chisel part. As a result, the presence or absence or position of the resin member 18 in the container 12 can be inspected with high accuracy regardless of the orientation or type of the resin member 18 attached to the container 12 .

(6) The angle formed by the transmission axis 23A of the first polarizer 23 and the transmission axis 24A of the second polarizer 24 is preferably a predetermined angle within the range of 15° or more and 75° or less. Therefore, a captured image Img3 with a large difference in brightness between the container 12 and the resin member 18, which is the background in the captured image Img3, can be obtained. The presence or absence or position of the member 18 can be inspected with high accuracy.

(7) The container inspection method includes irradiating light onto an inspection target region of the container 12 made of a light-transmitting inorganic material, inspecting the presence or absence or position of the light-transmitting resin member 18 attached to the container 12; 1 image generation process, a second image generation process, an imaging process, and an inspection process. In the first image generation step, the light from the first light source 21 passes through the first polarizer 23 and irradiates the inspection target region of the container 12 with the polarized light, and the first polarized light L1 transmitted through the container 12 is converted to the first polarized light L1 by the first polarizer. A first image Img1 is generated through an analyzer 25 oriented such that the transmission axis 25A intersects the transmission axis 23A of 23 . In the second image generation step, the light from the second light source 22 passes through the second polarizer 24 oriented such that the transmission axis 24A is at a different angle with respect to the transmission axis 23A of the first polarizer 23, and passes through the second light source 24. A region to be inspected of the container 12 is irradiated with the polarized light L2. By changing the phase difference of the second polarized light L2 at least either before or after passing through the container 12, the oscillation direction of the second polarized light L2 is changed to the transmission axes 23A and 24A of the first polarizer 23 and the second polarizer 24, respectively. The third polarized light L3 is obtained by rotating the light by an angle corresponding to the predetermined angle formed by the light beams, and the third polarized light L3 is passed through the analyzer 25 to generate the second image Img2. In the imaging step, a first image Img1 and a second image Img2 are captured. Then, in the inspection process, the presence or absence or position of the resin member 18 is inspected based on the captured image Img3 acquired in the imaging process. Therefore, the presence or absence or position of the resin member 18 in the container 12 can be inspected regardless of the orientation or type of the resin member 18 attached to the container 12 .

(Second embodiment)
Next, a container inspection device 14 according to a second embodiment will be described with reference to FIG. The container inspection device 14 of this embodiment does not include the wave plate 26 . That is, the wavelength plate 26 is eliminated and the analyzer 25 is replaced with two, a first analyzer 27 and a second analyzer 28 . A first imaging mechanism 31 has a first analyzer 27 and a second imaging mechanism 32 has a second analyzer 28 .

As shown in FIG. 8, the container inspection apparatus 14 includes a first image generation mechanism 31 that generates a first image Img1 (see FIGS. 6 and 7) and a second image Img2 (see FIGS. 6 and 7). ), and a second image generating mechanism 32 for generating the . Further, the container inspection device 14 includes a camera 20 that captures the first image Img1 and the second image Img2, and a control unit 50 that controls the first light source 21, the second light source 22, and the camera 20. In the second embodiment, the configurations of the first image generation mechanism 31 and the second image generation mechanism 32 are different from those in the first embodiment.

As shown in FIG. 8, the first image generating mechanism 31 comprises a first light source 21, a first polarizer 23, a first analyzer 27, a first mirror 33 and a second mirror . The second image generation mechanism 32 also includes a second light source 22 , a second polarizer 24 , a second analyzer 28 , a third mirror 35 and a fourth mirror 36 . Here, the first light source 21, the second light source 22, the first polarizer 23, and the second polarizer 24 have the same configurations as those in the first embodiment. It is arranged in the same position and orientation as in the first embodiment. The mirrors 33 to 36 also have the same configuration as in the first embodiment, and are arranged in the same positions and orientations as in the first embodiment with respect to the container 12 at the inspection position. Furthermore, there is also one camera 20, which is arranged in the same position and orientation as in the first embodiment. The contents of control by the control unit 50 are also the same as in the first embodiment. That is, the control unit 50 causes the CPU to execute the program PR shown in the flowchart of FIG. .

The first imaging mechanism 31 comprises a first analyzer 27 at a position on the optical path of the first polarization L1 between the container 12 in the inspection position and the camera 20 . In this example, the first analyzer 27 is arranged at a position between the container 12 in the inspection position and the first mirror 33 . The second image generating mechanism 32 also comprises a second analyzer 28 at a position on the optical path of the second polarization L2 between the container 12 in the inspection position and the camera 20 . In this example, the second analyzer 28 is positioned between the container 12 in the inspection position and the third mirror 35 .

Each of the first polarizer 23, the second polarizer 24, the first analyzer 27, and the second analyzer 28 is composed of a polarizing plate (for example, a polarizing filter). In FIG. 8, the transmission axes 23A, 24A, 27A, and 28A of the respective polarizers 23, 24 and the analyzers 27, 28 are indicated by the directions of a plurality of parallel lines drawn in the circle. direction. The transmission axes 23A and 24A of the first polarizer 23 and the second polarizer 24 differ from each other by a predetermined angle θ (for example, 45°) as in the first embodiment. The predetermined angle θ may be an angle within the range of 15° or more and 75° or less, or may be an angle outside this range as long as the inspection is possible.

Here, assuming that the horizontal direction parallel to the transport direction X is 0°, the transmission axis 24A is 0°, and the transmission axis 23A is inclined by a predetermined angle θ (for example, 45°) with respect to the horizontal (0°). Assuming that the counterclockwise direction is the positive direction when viewed from the light propagating direction, the transmission axis 23A is rotated by a predetermined angle θ from 0° in the positive direction.

Also, as shown in FIG. 8, the first polarizer 23 and the first analyzer 27 have a relationship in which their respective transmission axes 23A and 27A intersect. there is Here, the transmission axes 23A and 27A are not limited to 90°, but may be an angle A within the range of 80° to 100° (80°≦A≦100°). However, the angle A may be an angle other than the range of 80° to 100°.

Also, as shown in FIG. 8, the second polarizer 24 and the second analyzer 28 have a relationship in which their respective transmission axes 24A and 28A intersect. there is Here, the transmission axes 24A and 28A being "perpendicular" is not limited to 90°, but may be an angle A within the range of 80° to 100° (80°≤A≤100°). However, the angle A may be an angle other than the range of 80° to 100°. The angle A formed by the transmission axes 23A and 27A and the angle A formed by the transmission axes 24A and 28A are not limited to the same value and may be different values.

As shown in FIG. 8, in the first image generation mechanism 31, the light from the first light source 21 passes through the first polarizer 23, and the first polarized light L1 irradiates the first area including the inspection target area of the container 12. be done. The first polarized light L1 transmitted through the container 12 and the resin member 18 is transmitted through the first analyzer 27 to generate the first image Img1. The first image Img1 is incident on the camera 20 after being sequentially reflected by the first mirror 33 and the second mirror 34 .

In the second image generation mechanism 32, the second polarized light L2 obtained by passing the light from the second light source 22 through the second polarizer 24 illuminates the inspection target area of the container 12 from a light irradiation direction different from that of the first polarized light L1. A second area comprising: The second polarized light L2 transmitted through the container 12 and the resin member 18 is transmitted through the second analyzer 28 to generate a second image Img2. The second image Img2 is incident on the camera 20 after being sequentially reflected by the third mirror 35 and the fourth mirror 36 .

As shown in FIG. 5, the control unit 50 causes the first light source 21 and the second light source 22 to emit different light within the same one-frame imaging period IP during which the camera 20 performs one-time exposure and one-frame imaging operation. Light up in time. The imaging element in the camera 20 receives the first image Img1 during the first light emission period and receives the second image Img2 during the second light emission period within the same one-frame imaging period IP. As a result, the camera 20 captures the first image Img1 and the second image Img2 together in one-frame imaging operation to obtain a captured image Img3 (see FIGS. 6 and 7). Then, the control unit 50 performs image processing on the captured image Img3, and determines the presence or absence of the resin member 18 based on the captured image Img3 after the image processing. Further, the control unit 50 determines whether or not the container 12 is defective, and detects the position of the resin member 18 (including label position deviation determination), as in the first embodiment.

As described in detail above, according to the second embodiment, the following effects are obtained.
(8) The container inspection device 14 includes a first image generation mechanism 31 having a first light source 21, a first polarizer 23 and a first analyzer 27, a second light source 22, a second polarizer 24 and a second detector. and a second imaging mechanism 32 having photons 28 . The first image generation mechanism 31 irradiates the inspection target area of the container 12 with the first polarized light L1, which is the light from the first light source 21 that has passed through the first polarizer 23, and transmits the first polarized light L1 transmitted through the container 12. A first image Img1 is generated through a first analyzer 27 arranged in a direction in which the transmission axis 27A intersects the transmission axis 23A of the first polarizer 23. FIG. The second image generating mechanism 32 passes the light of the second light source 22 through a second polarizer 24 oriented such that the transmission axis 24A is at a different angle to the transmission axis 23A of the first polarizer 23. A region to be inspected of the container 12 is irradiated with the second polarized light L2. The second polarized light L2 transmitted through the container 12 is passed through a second analyzer 28 arranged such that the transmission axis 28A intersects the transmission axis 24A of the second polarizer 24 to generate a second image Img2. Further, the container inspection device 14 includes a camera 20 that captures the first image Img1 and the second image Img2, and an inspection unit that inspects the presence or absence or position of the resin member 18 based on the captured image Img3 acquired by the camera 20. 53.

Here, the first image Img1 and the second image Img2 have such a relationship that even if one of them has a dark resin member 18 portion, the other has a bright resin member 18 portion. Therefore, in the captured image Img3, the portion of the resin member 18 always becomes a bright portion, and the portion other than the resin member 18 becomes a dark portion. The inspection unit 53 inspects the presence or absence or position of the resin member 18 based on the captured image Img3. Therefore, the presence or absence or position of the resin member 18 in the container 12 can be inspected regardless of the orientation or type of the resin member 18 attached to the container 12 .

Furthermore, since only one camera 20 is required as in the first embodiment, the number of parts of the container inspection device 14 can be reduced, and the size of the device can be reduced. Moreover, in the second embodiment, the same effect as in the first embodiment can be obtained by using the two analyzers 27 and 28 without the wavelength plate 26 . Moreover, compared to the first embodiment, it is possible to reduce the types of parts without increasing the number of parts constituting the container inspection device 14 . Moreover, since the polarizers 23 and 24 and the analyzers 27 and 28 are composed of polarizing plates (for example, polarizing filters), a plurality of parts having different functions can be manufactured from a common material. Therefore, the container inspection device 14 can be manufactured relatively easily at a relatively low cost. In addition, according to the second embodiment, the effects (2), (4) to (6) of the first embodiment are similarly obtained.

(9) An article inspection method includes a first image generation process, a second image generation process, an imaging process, and an inspection process. In the first image generation step, the light from the first light source 21 irradiates the inspection target region of the container 12 with the first polarized light L1 that has passed through the first polarizer 23, and the first polarized light L1 transmitted through the container 12 is A first image Img1 is generated through a first analyzer 27 arranged in a direction in which the transmission axis 27A intersects the transmission axis 23A of the first polarizer 23. FIG. In the second image generation step, the light from the second light source 22 passes through the second polarizer 24 which is oriented so that the transmission axis 24A is at a different angle with respect to the transmission axis 23A of the first polarizer 23. A region to be inspected of the container 12 is irradiated with the two polarized lights L2. The second polarized light L2 transmitted through the container 12 is passed through a second analyzer 28 arranged such that the transmission axis 28A intersects the transmission axis 24A of the second polarizer 24 to generate a second image Img2. In the imaging step, a first image Img1 and a second image Img2 are captured. Then, in the inspection process, the presence or absence or position of the resin member 18 is inspected based on the captured image Img3 acquired in the imaging process. Therefore, the presence or absence or position of the resin member 18 in the container 12 can be inspected regardless of the orientation or type of the resin member 18 attached to the container 12 .

Embodiments are not limited to the above, and may be modified as follows.
- In the first embodiment and the second embodiment, the camera 20 performs an imaging operation for one container 12 in two frames, and the first image Img1 and the second image Img2 are captured in two different frames. You can take an image. In this case, the inspection unit 53 performs image processing separately on the first captured image including the first image Img1 and the second captured image including the second image Img2 acquired by the camera 20 . Then, if the resin member 18 is detected in one of the first captured image and the second captured image, it is determined that the resin member is present, and the resin member 18 is detected in both the first captured image and the second captured image. If not, it is determined that there is no resin member. Further, when the position of the resin member 18 is detected, the position of the resin member 18 in one of the first captured image and the second captured image in which the resin member 18 is detected is calculated to obtain the container. The relative position of the resin member 18 with respect to the article such as 12 is detected. Since the conveying height of the container 12 and the imaging height of the camera 20 are known, the detected position of the resin member 18 is within the allowable amount in the vertical direction Z from the normal height range assumed from the conveying height of the container 12. , the controller 50 determines that the resin member 18 (for example, a label) is misaligned. Since the first image Img1 and the second image Img2 are captured in two frames, it is easy to adjust the exposure time when capturing each frame, and the first image and the second image can be obtained with appropriate brightness or contrast. Cheap. Furthermore, when the camera 20 captures the first image Img1 and the second image Img2 in two frames, difference processing between frames is possible. Synthesis of the first image Img1 and the second image Img2 within one frame in each of the above-described embodiments is effective in shortening the processing time, but the difference image information cannot be obtained. On the other hand, if the camera 20 is configured to capture the first image Img1 and the second image Img2 in two frames, if the difference between the two images is small, the inspection unit 53 will take the difference between the frames. can improve detection accuracy. Therefore, the inspection unit 53 can detect the presence or absence or position of the resin member 18 on the article with high accuracy regardless of the orientation or type of the resin member 18 attached to the article.

- You may make the 1st light source 21 and the 2nd light source 22 light-emit simultaneously at the same timing. With this configuration as well, a captured image Img3 obtained by capturing the first image Img1 and the second image Img2 with the camera 20 can be obtained. position can be inspected.

- In each of the above embodiments, the first light source 21 and the second light source 22 are caused to emit light during inspection, but only one of the two light sources 21 and 22 may be caused to emit light. The control unit 50 grasps the direction or type of the resin member 18 attached to the container 12 and causes only one of the first light source 21 and the second light source 22 to emit light according to the direction or type of the resin member 18 . For example, when the type of the container 12 is switched, a first captured image including the first image Img1 and a second captured image including the second image Img2 are acquired separately for one container 12, and these two captured images are captured. One of the images in which the portion of the resin member 18 is a bright portion is specified, and the light source that emits light when the specified one of the captured images is captured is determined as the light source that emits light in subsequent inspections. In addition, if the control unit 50 is configured to switch one of the two light sources 21 and 22 to emit light according to information on the orientation or type of the resin member 18 attached to the container 12 to be inspected, the inspection line can Even if containers 12 with different orientations or types of resin members 18 are mixed, it can be handled. For example, code information such as a barcode attached to the container 12 is read on the upstream side of the inspection position to grasp the type of the container 12, and depending on the orientation or type of the resin member 18 attached to that type of container, It is sufficient to switch the light source to emit light.

- In the first embodiment, the analyzer 25 may be divided into a first analyzer that constitutes the first image generation mechanism 31 and a second analyzer that constitutes the second image generation mechanism 32. good. In this case, a first analyzer is placed at a position on the optical path of the first polarization L1 between the container in the inspection position and the camera 20, and a second analyzer is placed between the container in the inspection position and the camera 20. may be arranged at a position on the optical path of the third polarized light L3. For example, a first analyzer is placed between the container 12 and the first mirror 33 or between the first mirror 33 and the second mirror 34 . A second analyzer is arranged between the wave plate 26 and the third mirror 35 or between the third mirror 35 and the fourth mirror 36 . The images Img1 and Img2 of the two polarized light beams L2 and L3 transmitted through the first analyzer and the second analyzer, respectively, are picked up by the common camera 20 .

• In the first embodiment, a third image generation mechanism may be added. The third image generation mechanism has basically the same configuration as the second image generation mechanism, and has a third light source, a third polarizer, an analyzer, and a second wavelength plate as an example of a phase shifter. The third light source has a light irradiation direction different from that of the first light source and the second light source. The transmission axes of the first polarizer, the second polarizer, and the third polarizer have different angles. The angles of these three polarizers are different from each other. Further, since the transmission axes of the third polarizer and the analyzer are not perpendicular to each other, the second wavelength plate allows the transmission axes of the first polarizer and the third polarizer to pass through an angle corresponding to the predetermined angle formed by the respective transmission axes of the first polarizer and the third polarizer. Rotate the vibration direction of polarized light (polarization plane). Also, in the second embodiment, a third image generation mechanism may be added. The third image generation mechanism has basically the same configuration as the first image generation mechanism 31 and has a third light source, a third polarizer and a third analyzer. In any of the above configurations, the control unit 50 controls the light emission control of the three light sources and the imaging timing of the camera 20, and the first image Img1, the second image Img2, and the third image are different depending on the camera 20. The image may be captured at the same image capturing timing, or may be captured at the same image capturing timing.

- In the first embodiment, one or both of the polarizers 23 and 24 and the analyzer 25 may be replaced with a polarizing plate and a polarizing prism. Further, in the second embodiment, at least one of the polarizers 23 and 24 and the analyzers 27 and 28 may be replaced with a polarizing plate and may be a polarizing prism.

- In the first embodiment, the retarder is not limited to the wave plate 26, but may be a compensator having a variable phase difference.
- In 2nd Embodiment, you may arrange|position the 1st analyzer 27 in the position on an optical path between the 1st mirror 33 and the 2nd mirror 34. FIG. Also, the second analyzer 28 may be arranged at a position on the optical path between the third mirror 35 and the fourth mirror 36 . Furthermore, if the arrangement space can be secured, the first analyzer 27 can be arranged on the optical path between the mirror 34 and the camera 20, or the second analyzer 28 can be arranged on the optical path between the mirror 36 and the camera 20. position.

- The resin member 18 is not limited to an annular member attached to the container 12 or a label such as a shrink label attached to the outer peripheral surface of the container 12 . For example, it may be a packaging film for the container 12 or a sealing film applied over the lid 19 and the neck of the container 12 . Moreover, not only a film but also a sheet may be used. Moreover, the resin member 18 is not limited to being attached to the outside or the outer peripheral surface of the container 12 , and may be put inside the container 12 . For example, it may be inspected whether or not the resin member 18 to be put into the container 12 has been erroneously inserted or whether or not the resin member 18 to be taken out from the container 12 has been erroneously discharged.

- The resin member 18 is not limited to being entirely transparent or translucent. For example, a resin member having a transparent or translucent part, such as a printed label, may be used.
- The resin member 18 is not limited to a film or sheet, and may be, for example, a block-shaped member.

- The container 12 is not limited to a glass bottle, and may be a glass cup, plate, vase, or the like. In addition, the inorganic material is not limited to glass, which is amorphous, and may be a crystal material such as silica, alumina, or zirconia made of an inorganic material and having optical transparency.

• Articles are not limited to containers. Any article made of an inorganic material having optical transparency may be used. For example, plate glass, lighting glass products, glass optical components such as lenses, and glass ornaments may be used.

DESCRIPTION OF SYMBOLS 11... Container inspection system, 12... Container as an example of goods, 13... Conveying part, 14... Container inspection apparatus as an example of goods inspection apparatus, 15, 15A... Conveyor, 16, 16A, 16B, 16C... Conveyor apparatus, DESCRIPTION OF SYMBOLS 17... Sensor, 18... Resin member, 19... Lid, 20... Camera as an example of imaging part, 21... First light source, 22... Second light source, 23... First polarizer, 23A... Transmission axis, 24... Second light source 2 polarizers, 24A... transmission axis, 25... analyzer, 25A... transmission axis, 26... wavelength plate as an example of phase shifter, 27... first analyzer, 27A... transmission axis, 28... second analyzer, 28A... transmission axis, 31... first image generating mechanism, 32... second image generating mechanism, 33... first mirror, 34... second mirror, 35... third mirror, 36... fourth mirror, 50... control Unit 51 Memory 52 Drive control unit 53 Inspection unit PR Program L1 First polarization L2 Second polarization L3 Third polarization IP One frame imaging period Img1 First image, Img2: second image, Img3: captured image.

Claims (8)

An article inspection apparatus for inspecting the presence or absence or position of a light-transmitting resin member attached to an article by irradiating light onto an inspection target area of an article made of a light-transmitting inorganic material,
It has a first light source, a first polarizer and an analyzer, the light of the first light source passes through the first polarizer, irradiates the inspection target area of the article with the first polarized light, and transmits the article. a first image generating mechanism for generating a first image by passing one polarized light through the analyzer oriented such that the transmission axis crosses the transmission axis of the first polarizer;
It has a second light source, a second polarizer, a phase shifter and an analyzer, and is arranged such that the light from the second light source has a transmission axis at a different angle with respect to the transmission axis of the first polarizer. A region to be inspected of the article is irradiated with the second polarized light that has passed through the second polarizer, and the second polarized light is passed through the phase shifter at least before and after passing through the article, and the position of the second polarized light is By changing the phase difference, the vibration direction of the second polarized light is rotated by an angle corresponding to the predetermined angle formed by the transmission axes of the first polarizer and the second polarizer, and the third polarized light is obtained. a second image generating mechanism for passing three polarized light beams through the analyzer to generate a second image;
an imaging unit that captures the first image and the second image;
and an inspection unit that inspects the presence or absence or position of the resin member based on the captured image acquired by the imaging unit. The retarder oscillates the polarized light by an angle (nπ-θ) (where n is an integer equal to or greater than 0) corresponding to a predetermined angle θ between the transmission axes of the first polarizer and the second polarizer. 2. The article inspection apparatus according to claim 1, wherein the phase difference is changed by a rotatable amount. An article inspection apparatus for inspecting the presence or absence or position of a light-transmitting resin member attached to an article by irradiating light onto an inspection target area of an article made of a light-transmitting inorganic material,
Having a first light source, a first polarizer and a first analyzer, the light from the first light source passes through the first polarizer and irradiates the inspection target area of the article with the first polarized light, which is transmitted through the article. a first image generating mechanism for generating a first image of the first polarized light through the first analyzer arranged in a direction in which the transmission axis intersects the transmission axis of the first polarizer;
The second light source has a second light source, a second polarizer, and a second analyzer, and the light from the second light source is arranged in a direction such that the transmission axis is at a different angle with respect to the transmission axis of the first polarizer. A region to be inspected of the article is irradiated with the second polarized light that has passed through two polarizers, and the second polarized light that has passed through the article is arranged in a direction in which the transmission axis crosses the transmission axis of the second polarizer. a second image generating mechanism for generating a second image through said second analyzer;
an imaging unit that captures the first image and the second image;
and an inspection unit that inspects the presence or absence or position of the resin member based on the captured image acquired by the imaging unit. A drive control unit that controls the imaging unit,
4. The method according to any one of claims 1 to 3, wherein the drive control section causes the imaging section to capture the first image and the second image in one frame of imaging operation. Article inspection equipment. 5. The article inspection apparatus according to claim 4, wherein the drive control section causes the first light source and the second light source to emit light at different timings within the same one-frame imaging period of the imaging section. 2. The first light source and the second light source are caused to emit light at different timings, and the imaging unit captures the first image and the second image in two separate and different frames. 4. The article inspection device according to any one of -3. An article inspection method for inspecting the presence or absence or position of a light-transmitting resin member attached to the article by irradiating light onto an inspection target area of an article made of a light-transmitting inorganic material,
Light from a first light source passes through a first polarizer and irradiates a region to be inspected of the article with the first polarized light, and the first polarized light that has passed through the article has a transmission axis with respect to the transmission axis of the first polarizer. a first imaging step of generating a first image through an analyzer oriented with the
irradiating a region to be inspected of the article with the second polarized light that has passed through a second polarizer arranged such that the light from the second light source has a transmission axis at a different angle with respect to the transmission axis of the first polarizer; The phase difference of the second polarized light is changed at least either before or after it is transmitted through the article, and the oscillation direction of the second polarized light is set to a predetermined value formed by the transmission axes of the first polarizer and the second polarizer. a second image generating step of rotating the third polarized light by an angle corresponding to the angle and passing the third polarized light through the analyzer to generate a second image;
an imaging step of imaging the first image and the second image;
an inspection step of inspecting the presence or absence or position of the resin member in the inspection target area based on the captured image acquired in the imaging step;
An article inspection method comprising: An article inspection method for inspecting the presence or absence or position of a light-transmitting resin member attached to the article by irradiating light onto an inspection target area of an article made of a light-transmitting inorganic material,
Light from a first light source passes through a first polarizer and irradiates a region to be inspected of the article with the first polarized light, and the first polarized light that has passed through the article is directed in a direction in which the transmission axis intersects the first polarizer. a first imaging step of generating a first image through a first positioned analyzer;
The light from the second light source passes through a second polarizer arranged in a direction where the transmission axis is at a different angle with respect to the transmission axis of the first polarizer, and the inspection target area of the article is irradiated with the second polarized light. a second image generating step of generating a second image of the second polarized light transmitted through the article through a second analyzer arranged in a direction in which the transmission axis crosses the transmission axis of the second polarizer; When,
an imaging step of imaging the first image and the second image;
an inspection step of inspecting the presence or absence or position of the resin member based on the captured image acquired by the imaging unit;
An article inspection method comprising:

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