JP2021181899A - Winding angle inspection device - Google Patents

Abstract

To provide a winding angle inspection device which does not use an external optical system other than a camera.SOLUTION: A winding angle inspection device inspects a winding angle of a second object Y to a first object X on the basis of a first object mark x3 provided in a first object X and a second object mark y3 provided in a second object Y with respect to an inspection object in which the second object Y is screwed to the first object X. The winding angle inspection device includes: a plurality of cameras which are arranged at positions opposed to the first object mark x3 and the second object mark y3 and which directly image a first object image including the first object mark x3 and a second object image including the second object mark y3; evaluation means for calculating a winding angle based on the first object image and the second object image and evaluating the winding angle; and output means for outputting an evaluation result of the evaluation means.SELECTED DRAWING: Figure 1

Description

The present invention relates to a winding angle inspection device.

The following Patent Document 1 discloses a method for inspecting a cap winding state in a bottle / cap assembly. In this inspection method, the optical system lens and the camera are placed above the vertical central axis of the bottle / cap assembly, the bottle confirmation mark and the cap confirmation mark are not directly illuminated with light, and the cap confirmation mark on the skirt of the cap is not directly irradiated. The bottle confirmation mark and the cap confirmation mark are simultaneously imaged by one camera through the optical system lens while illuminating the part where the is not formed is directly irradiated with light. The quality of the wound state of the cap is judged from the image.

Japanese Unexamined Patent Publication No. 2003-237890

By the way, in the above background technology, by using an optical system lens (aspherical lens) having a special shape, a bottle is used with one camera provided above the cap, that is, at a position not facing the bottle confirmation mark and the cap confirmation mark. The confirmation mark and the cap confirmation mark are imaged at the same time. That is, with the above background technology, it is difficult to accurately detect the positional relationship between the bottle confirmation mark and the cap confirmation mark because the image distortion caused by an external optical system such as an optical system lens (aspherical lens) is relatively large. Is. Therefore, it is difficult for the above background technique to realize sufficient inspection accuracy for the cap winding state.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a winding angle inspection device that does not use an external optical system other than a camera.

In order to achieve the above object, in the present invention, as a first solution for a winding angle inspection device, an inspection object in which a second object is screwed onto the first object is provided on the first object. A winding angle inspection device that inspects the winding angle of the second object with respect to the first object based on the first object mark and the second object mark provided on the second object, and is the first object mark. A plurality of cameras arranged at positions facing the second object mark and directly capturing a first object image including the first object mark and a second object image including the second object mark, and the first object. A means for calculating the winding angle θ based on the image and the second object image, and providing an evaluation means for evaluating the winding angle θ and an output means for outputting the evaluation result of the evaluation means. adopt.

In the present invention, as a second solution for the winding angle inspection device, in the first solution, the first object is the container body, and the first object mark is provided on the mouth of the container body. If so, the camera adopts a means of being provided at a position facing the mouth portion.

In the present invention, as a third solution for the winding angle inspection device, in the second solution, the camera is provided around the mouth at a plurality of positions divided by a predetermined angle. , Is adopted.

In the present invention, as the fourth solution means for the winding angle inspection device, in any one of the first to third solutions, the second object is a lid and the second object mark is the lid. When it is provided on the top surface, the camera is provided at a position facing the top surface of the lid.

In the present invention, as a fifth solution for the winding angle inspection device, in any one of the first to fourth solutions, the camera has a first object including the first object mark and the second object. A means of capturing a shared image in which a second object including an object mark is reflected at the same time is adopted.

In the present invention, as the sixth solution means for the winding angle inspection device, in any one of the first to fifth solutions, the evaluation means is the first object based on the first object image. The relative position θ1 of the first object mark with respect to the reference position is detected, the relative position θ2 of the second object mark with respect to the reference position of the first object is detected based on the second object image, and the relative position θ1 A means of calculating the winding angle θ based on the positional relationship with the relative position θ2 is adopted.

In the present invention, as a seventh solution relating to the winding angle inspection device, in any one of the first to sixth solutions, the inspection object is a PET whose cap is screwed to the mouth of the bottle body. Adopt the means of being a bottle.

According to the present invention, it is possible to provide a winding angle inspection device that does not use an external optical system other than a camera.

It is a schematic diagram which shows the structure of the PET bottle B in 1st Embodiment of this invention. It is a block diagram which shows the whole structure of the winding angle inspection apparatus A which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows the arrangement of the mouth camera 1A to 1D and the cap camera 2 in the winding angle inspection apparatus A which concerns on 1st Embodiment of this invention. It is a flowchart which shows the operation of the winding angle inspection apparatus A which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows the detection process _{of the angle deviation θ 1} and the angle deviation θ ₂ in the first embodiment of the present invention. It is a schematic diagram which shows the structure of the PET bottle B1 in the 2nd Embodiment of this invention. It is a block diagram which shows the whole structure of the winding angle inspection apparatus A1 which concerns on 2nd Embodiment of this invention. It is a schematic diagram which shows the arrangement of the shared cameras 5A to 5D in the winding angle inspection apparatus A1 which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the operation of the winding angle inspection apparatus A1 which concerns on 2nd Embodiment of this invention. It is a schematic diagram which shows the detection process of the angle deviation θ1 and the angle deviation θ2 in the second embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
First, the first embodiment of the present invention will be described with reference to FIGS. 1 to 5. The winding angle inspection device A according to the first embodiment is an inspection device in which the PET bottle B shown in FIG. 1 is the inspection target.

As shown in FIG. 1, the PET bottle B is a substantially cylindrical article (commodity) in which a cap Y (cover) is attached to a bottle body X (container body). A predetermined content (liquid) is contained in the PET bottle B, and the internal space is sealed by attaching the cap Y. Such a PET bottle B is conveyed to a predetermined inspection position in an upright posture, that is, a posture in which the central axis is in the vertical direction as shown in the figure. The bottle body X corresponds to the first object of the present invention, and the cap Y corresponds to the second object of the present invention.

The bottle body X is a substantially cylindrical container (resin container) formed of PET (polyethylene terephthalate) which is a kind of synthetic resin, and a bottle mouth portion x1 is provided at the upper portion. The bottle mouth portion x1 is an opening formed in a substantially cylindrical shape concentric with the bottle body X, and a spiral protrusion (not shown) is formed on the peripheral surface (mouth peripheral surface x2). Further, on the peripheral surface x2 of the mouth portion, a mouth portion mark x3 is formed at the lower portion (neck ring portion) of the spiral protrusion. The mouth mark x3 is, for example, a recess having a specific shape. The mouth mark x3 corresponds to the first object mark of the present invention.

The cap Y is a lid that closes the bottle mouth portion x1 and is a substantially cylindrical resin molded product that is screwed into the bottle mouth portion x1. Inside the peripheral surface of the cap Y (cap peripheral surface y1), a spiral protrusion (not shown) screwing with the spiral protrusion is formed. Further, the upper end of the cap peripheral surface y1 is closed, and the top surface (cap top surface y2) is provided in a state orthogonal to the central axis of the cap Y. That is, the cap top surface y2 is a circular plane orthogonal to the central axis of the cap Y, and the cap mark y3 is formed at a predetermined position.

The cap mark y3 is, for example, a dent having a specific shape different from the mouth mark x3 described above. Such a cap Y has its own spiral protrusion screwed into the spiral protrusion of the bottle mouth portion x1 by rotating the cap Y in a predetermined direction around the central axis with the lower end portion in contact with the mouth portion x1. It is attached to the bottle body X. The cap mark y3 corresponds to the second object mark of the present invention.

The winding angle inspection device A according to the first embodiment has a bottle body X (container) for a PET bottle B in which the mouth mark x3 and the cap mark y3 are provided in orientations (positions) that differ by approximately 90 °. ) Is an inspection device for inspecting the winding tightening angle θ of the cap Y (lid) screwed to). As shown in FIG. 2, the winding angle inspection device A includes four mouth cameras 1A to 1D, one cap camera 2, an arithmetic unit 3, and a display device 4.

As shown in FIG. 3, the four mouth cameras 1A to 1D are cameras provided facing the bottle mouth x1 of the bottle body X, and are images of the bottle mouth x1 including the mouth mark x3. (Still image) is imaged as a mouth image. These four mouth cameras 1A to 1D output an image signal (mouth image signal) indicating the mouth image of the bottle to the arithmetic unit 3. The mouth image corresponds to the first object image of the present invention.

Further, as shown in FIG. 3A, these four mouth cameras 1A to 1D are divided by a predetermined angle division, that is, an angle division of 90 ° around the center P of the bottle mouth portion x1. It is provided at each of a plurality of positions (4 locations). That is, of the four mouth cameras 1A to 1D, the first mouth camera 1A is a reference position, that is, a position of 0 ° as an angle (reference) around the bottle mouth x1 (range of 360 °). It is provided at the corner).

Further, the second mouth camera 1B is provided at a position of + 90 ° to the left from the reference angle around the center P of the bottle mouth x1. Further, the third mouth camera 1C is provided at a position of + 180 ° to the left from the reference angle around the center P of the bottle mouth x1. Further, the fourth mouth camera 1D is provided at a position of +270 ° (that is, −90 ° from the reference angle) to the left of the reference angle around the center P of the bottle mouth x1.

These four mouth cameras 1A to 1D have regions around the center P of the bottle mouth x1 that slightly exceed the range of + 45 ° to -45 ° (total range of 90 °) based on their own positions. Is the imaging range. That is, the first mouth camera 1A has an imaging range slightly exceeding the first range R1 of −45 ° to + 45 ° around the center P (range of 360 °) of the bottle mouth x1. Such a first mouth camera 1A captures a first mouth image in which the first range R1 of −45 ° to + 45 ° is reflected in the center around the center P of the bottle mouth x1. The first mouth image signal showing the first mouth image is output to the arithmetic unit 3.

The second mouth camera 1B has an imaging range slightly exceeding the second range R2 of + 45 ° to + 135 ° around the center P of the bottle mouth x1. Such a second mouth camera 1B captures a second mouth image in which the second range R2 of + 45 ° to + 135 ° is reflected in the center around the center P of the bottle mouth x1. The second mouth image signal showing the mouth image of 2 is output to the arithmetic unit 3.

The third mouth camera 1C has an imaging range slightly exceeding the third range R3 of + 135 ° to + 225 ° around the center P of the bottle mouth x1. Such a third mouth camera 1C captures a third mouth image in which the third range R3 of + 135 ° to + 225 ° is reflected in the center around the center P of the bottle mouth x1. A third mouth image signal showing the mouth image of 3 is output to the arithmetic unit 3.

Further, the fourth mouth camera 1D has an imaging range around the center P of the bottle mouth x1 slightly exceeding the fourth range R4 of +225 ° to +315 ° (−45 °). Such a fourth mouth camera 1D captures a fourth mouth image in which the fourth range R4 of + 225 ° to + 315 ° (−45 °) is reflected in the center around the center P of the bottle mouth x1. An image is taken and a fourth mouth image signal showing the fourth mouth image is output to the arithmetic unit 3.

As shown in FIG. 3, one cap camera 2 is a camera provided so as to face the cap top surface y2 of the cap Y, and an image (still image) of the cap Y including the cap mark y3 is a cap image. Image as. The cap camera 2 outputs an image signal (cap image signal) indicating the cap image to the arithmetic unit 3. The cap image corresponds to the second object image of the present invention.

Further, the cap camera 2 is located at the center of the circular cap top surface y2, that is, directly above the central axes of the bottle body X and the cap Y. Such a cap camera 2 captures a cap image in which the cap top surface y2 is reflected in the center, and outputs a cap image signal indicating the cap image to the arithmetic unit 3.

Here, the above-mentioned first to fourth mouth cameras 1A to 1D and the cap camera 2 are both cameras whose imaging wavelength range is visible light. That is, the first to fourth mouth cameras 1A to 1D and the cap camera 2 are image pickup devices that capture the first to fourth mouth images and cap images as visible images.

Of the first to fourth mouth cameras 1A to 1D and the cap cameras 2, the first to fourth mouth cameras 1A to 1D have the mouth mark x3 (first object mark). It is a camera that is arranged at opposite positions and directly captures a mouth image (first object image) including a mouth mark x3 without going through an external optical system. Further, the cap camera 2 is a camera that directly captures a cap image (second object image) including the cap mark y3 (second object mark) without going through an external optical system.

The arithmetic unit 3 controls the first to fourth mouth cameras 1A to 1D and the cap camera 2, and the first to first ones input from the first to fourth mouth cameras 1A to 1D, respectively. The winding angle θ of the cap Y (cover) with respect to the bottle body X (container) is calculated based on the mouth image signal of 4, the cap image signal input from the cap camera 2, and the external signal input from the host control device. It is an evaluation means to do.

The arithmetic unit 3 is a kind of computer, and receives image signals from a storage unit for storing a predetermined inspection program or the like, first to fourth mouth cameras 1A to 1D, and a cap camera 2, and displays the display device 4. It is equipped with an input / output unit that outputs inspection results and an arithmetic unit that executes inspection programs.

Although details will be described later, this arithmetic unit 3 acquires cap image signals and first to fourth mouth image signals for a plurality of PET bottles B sequentially transported to inspection positions by an external transport device, respectively. The winding angle θ is sequentially calculated by subjecting these cap image signals and the first to fourth mouth image signals with information processing according to the above inspection program.

Further, the arithmetic unit 3 sequentially evaluates the winding tightening angle θ by sequentially comparing the winding tightening angle θ with a predetermined evaluation standard. Further, the arithmetic unit 3 sequentially outputs the evaluation result, that is, the inspection result of each PET bottle B, as an inspection signal to the display device 4.

The display device 4 is a device that displays an image of the inspection result based on the inspection signals sequentially input from the arithmetic unit 3. The display device 4 displays the inspection results of the plurality of PET bottles B sequentially input from the arithmetic unit 3 in chronological order, that is, in the inspection order. It should be noted that such a display device 4 corresponds to the output means of the present invention.

Next, the operation of the winding angle inspection device A according to the first embodiment will be described in detail according to the flowchart shown in FIG.

When the PET bottle B is conveyed to the inspection position in the winding angle inspection device A, an arrival signal (external signal) is input to the arithmetic unit 3 from the external host control device. Upon receiving this arrival signal, the arithmetic unit 3 instructs the first to fourth mouth cameras 1A to 1D and the cap camera 2 to take an image. As a result, the first to fourth mouth cameras 1A to 1D capture the first to fourth mouth images, and the cap camera 2 captures the cap image (step S1).

Then, the arithmetic unit 3 acquires the first to fourth mouth images as the first to fourth mouth image signals, and acquires the cap image as the cap image signal. Then, the arithmetic unit 3 performs the expansion process to the plane coordinate system and the mutual combination process on the first to fourth mouth images, so that one combined image as shown in FIG. 5A is formed. Generate Gk (step S2).

Here, since the bottle mouth portion x1 has a cylindrical shape having a predetermined radius, the position on the first to fourth mouth portion images and the position on the mouth portion peripheral surface x2 in the real space deviate from each other. This amount of deviation depends on the shape (size and curvature) of the bottle mouth portion x1. Therefore, in order to accurately evaluate the position of the mouth mark x3 on the mouth peripheral surface x2, it is necessary to correct the positional deviation of the mouth mark x3 due to the shape of the bottle mouth portion x1.

In the above expansion process, in order to correct such a positional deviation, the image (image of the curved coordinate system) of the bottle mouth portion x1 (the peripheral surface of the mouth portion x2) curved with a predetermined curvature is coordinated with the image of the plane coordinate system. This is an image process for generating the first to fourth developed opening images by converting. The combination processing is an image process for generating one combined image Gk by connecting such first to fourth expansion opening images in the order of angles around the center P of the bottle opening x1.

When the combination process is completed, the arithmetic unit 3 performs a feature extraction process (step S3). This feature extraction process is a process of extracting an image portion (mouth feature portion) having a shape similar to the mouth mark x3 from the combined image Gk. By such a feature extraction process, the mouth feature portion in the combined image Gk is extracted as a mouth mark candidate.

Although one or a plurality of such mouth mark candidates are extracted, the arithmetic unit 3 narrows down the mouth mark candidates to one by performing exclusive processing on the plurality of mouth mark candidates (step S4). .. This exclusive processing is conditional on, for example, the size of the mouth mark candidate, and the mouth mark candidate that is extremely large with respect to the size of the mouth mark x3 is excluded.

Then, the arithmetic unit 3 performs a determination process of whether or not the mouth mark candidates narrowed down to one by the exclusive process can be specified as the mouth mark x3 (step S5). In this determination process, the shape and size of the mouth mark candidate are evaluated again, and it is determined whether or not the mouth mark candidate is truly the mouth mark x3. Then, when the determination in step S5 is "Yes", the arithmetic unit 3 specifies the mouth mark candidate as the mouth mark x3.

Subsequently, the arithmetic unit 3 sets the search range of the cap mark y3 for the circular cap image Gc shown in FIG. 5 (b) (step S6). That is, the range of the position of the cap mark y3 on the cap top surface y2 in the radial direction is known in advance by the specifications of the cap Y. Therefore, the arithmetic unit 3 sets the range in which the cap mark y3 can exist as the search range in the radial direction of the cap top surface y2.

Then, the arithmetic unit 3 extracts an image portion (cap feature portion) having a shape and size similar to that of the cap mark y3 within such a search range. Then, the arithmetic unit 3 performs a determination process of whether or not the cap characteristic portion may be specified as the cap mark y3 (step S7).

In this step S7, the arithmetic unit 3 detects the cap mark y3 by evaluating the shape and size of the cap feature portion. Then, when the determination in step S7 is "Yes", the arithmetic unit 3 specifies the cap characteristic portion as the cap mark y3. That is, by going through the above-mentioned steps S2 to S7, the mouth mark x3 in the combined image Gk and the cap mark y3 in the cap image Gc are specified.

When the arithmetic unit 3 specifies the mouth mark x3 and the cap mark y3 in this way, the arithmetic unit 3 performs a calculation process of the winding angle θ (step S8). In this calculation process, as shown in FIG. 5A, the arithmetic unit 3 calculates the angle deviation θ ₁ of the mouth mark x3 with respect to the reference angle (0 °) in the combined image Gk as the first relative position.

Further, as shown in FIG. 5B, the arithmetic unit 3 has a detection line that matches the reference angle and passes through the center P of the cap Y (cap top surface y2), the cap mark y3, and the center P. The angle deviation θ ₂ of the line is calculated as the second relative position. Then, the arithmetic unit 3 calculates the difference (θ ₁ − θ _{2 ) between the angle deviation θ 1} and the angle deviation θ ₂ as the winding angle θ. That is, the arithmetic unit 3 calculates the winding angle θ based on the positional relationship between the first relative position and the second relative position.

Then, the arithmetic unit 3 determines whether or not the winding angle θ is within the range of the predetermined threshold value θref (step S9). If the determination in step S9 is "Yes", the arithmetic unit 3 determines that the PET bottle B having the winding tightening angle θ is acceptable (step S10). If the determination in step S9 is "No", the arithmetic unit 3 determines that the PET bottle B having the winding tightening angle θ is rejected (step S11). Even when the determination in steps S5 and S7 described above is "No", the PET bottle B having the winding tightening angle θ is determined to be unacceptable (step S11).

As described above, the winding angle inspection device A according to the present embodiment includes four mouth cameras 1A to 1D for capturing the mouth mark x3 and a cap camera 2 for capturing the cap mark y3. .. That is, this winding angle inspection device A is for four mouths whose direction (posture) is set to be 90 ° different from that of the mouth mark x3 and the cap mark y3 which are different by approximately 90 °. The cameras 1A to 1D and the cap camera 2 are provided.

According to such a winding angle inspection device A, the winding angle θ of the PET bottle B is inspected by using the four mouth cameras 1A to 1D and the cap camera 2, which is special as in the conventional case. It is not necessary to use an optical system lens (external optical system). Therefore, according to the first embodiment, it is possible to provide the winding angle inspection device A that does not use an external optical system other than the camera.

[Second Embodiment]
Subsequently, a second embodiment of the present invention will be described with reference to FIGS. 6 to 10. The winding angle inspection device A1 according to the second embodiment is an inspection device whose inspection target is the PET bottle B1 shown in FIG. In FIGS. 6 to 10, the same components as those in FIGS. 1 to 5 of the first embodiment are designated by the same reference numerals.

This PET bottle B1 is the PET bottle B of the first embodiment in which the cap Y is replaced with the cap Y1. That is, this PET bottle B1 is different from the PET bottle B of the first embodiment only in the structure of the cap Y1, and is composed of the bottle body X and the cap Y1 of the first embodiment.

Further, the cap Y1 is provided with a cap mark y4 in place of the cap mark y3 of the first embodiment, and is the same as the cap Y of the first embodiment except for the cap mark y4. The cap mark y3 of the first embodiment is provided on the cap top surface y2, but the cap mark y4 of the second embodiment is not the cap top surface y2 but the cap peripheral surface y1 as shown in FIG. 6 (b). It is provided in.

Such a cap mark y4 corresponds to the second object mark of the present invention. The PET bottle B1 provided with such a cap Y1 is conveyed in an upright posture as in the PET bottle B of the first embodiment. Further, in such a PET bottle B1, the bottle body X corresponds to the first object of the present invention, and the cap Y1 corresponds to the second object of the present invention.

That is, the PET bottle B (inspection object) of the first embodiment is provided with the cap mark y3 in a direction (posture) substantially different from the mouth mark x3 by approximately 90 °, but the PET bottle of the second embodiment is provided. The B1 (object to be inspected) is provided so that the mouth mark x3 and the cap mark y4 are oriented substantially in the same direction, that is, can be visually recognized from the side of the PET bottle B1 in an upright posture.

The winding tightening angle inspection device A1 according to the second embodiment inspects the winding tightening angle θ of the cap Y1 screwed into the bottle body X with respect to such a PET bottle B1. As shown in FIG. 7, the winding angle inspection device A1 includes four shared cameras 5A to 5D, an arithmetic unit 3A, and a display device 4.

As shown in FIG. 8, the four shared cameras 5A to 5D are cameras provided so as to face the bottle mouth portion x1 of the bottle body X and the cap peripheral surface y1 of the cap Y1. These shared cameras 5A to 5D capture a still image in which the bottle mouth portion x1 including the mouth portion mark x3 and the cap peripheral surface y1 including the cap mark y4 are simultaneously captured as a shared image. That is, the shared image is a still image including an image portion (mouth portion image) of the bottle mouth portion x1 and an image portion (cap image) of the cap peripheral surface y1.

Here, in such a shared image, the image portion of the bottle mouth portion x1 is the mouth portion image in the second embodiment, and corresponds to the first object image of the present invention. Further, the image portion of the cap peripheral surface y1 is the cap image in the second embodiment, and corresponds to the second object image of the present invention.

As shown in FIG. 8A, the above-mentioned four shared cameras 5A to 5D are divided by a predetermined angle division, that is, an angle division of 90 ° around the center P of the bottle mouth portion x1, that is, the cap peripheral surface y1. It is provided at each of a plurality of positions (4 locations). That is, the positions of the four shared cameras 5A to 5D around the center P of the bottle mouth portion x1 and the cap peripheral surface y1 are the same as those of the mouth portion cameras 1A to 1D of the first embodiment.

The first shared camera 5A is provided at a reference position, that is, a position (reference angle) of 0 ° as a reference position, that is, around the bottle mouth portion x1 and the cap peripheral surface y1 (range of 360 °). The second shared camera 5B is provided at a position of + 90 ° to the left from the reference angle around the center P of the bottle mouth portion x1 and the cap peripheral surface y1.

The third shared camera 5C is provided at a position of + 180 ° to the left from the reference angle around the center P of the bottle mouth portion x1 and the cap peripheral surface y1. Further, the fourth shared camera 5D is provided at a position of +270 ° (that is, −90 ° from the reference angle) to the left of the reference angle around the center P of the bottle mouth portion x1 and the cap peripheral surface y1.

Similar to the mouth cameras 1A to 1D of the first embodiment, these four shared cameras 5A to 5D slightly cover a range of + 45 ° to −45 ° (a range of 90 ° in total) based on their own positions. The area that exceeds is defined as each imaging range.

That is, the first shared camera 5A uses a region slightly exceeding the first range R1 of −45 ° to + 45 ° as an imaging range around the center P (range of 360 °) of the bottle mouth portion x1 and the cap peripheral surface y1. There is. Such a first shared camera 5A captures a first shared image in which the first range R1 of −45 ° to + 45 ° is reflected in the center around the center P of the bottle mouth portion x1 and the cap peripheral surface y1. , The first shared image signal indicating the first shared image is output to the arithmetic unit 3A.

The second shared camera 5B has an imaging range slightly exceeding the second range R2 of + 45 ° to + 135 ° around the center P of the bottle mouth portion x1 and the cap peripheral surface y1. Such a second shared camera 5B captures a second shared image in which the second range R2 of + 45 ° to + 135 ° is reflected in the center around the center P of the bottle mouth portion x1 and the cap peripheral surface y1. The second shared image signal indicating the second shared image is output to the arithmetic unit 3A.

The third shared camera 5C has an imaging range of + 135 ° to + 225 ° slightly exceeding the third range R3 around the center P of the bottle mouth portion x1 and the cap peripheral surface y1. Such a third shared camera 5C captures a third shared image in which the third range R3 of + 135 ° to + 225 ° is reflected in the center around the center P of the bottle mouth portion x1 and the cap peripheral surface y1. The third shared image signal indicating the third shared image is output to the arithmetic unit 3A.

Further, the fourth shared camera 5D has an imaging range slightly exceeding the fourth range R4 of +225 ° to +315 ° (−45 °) around the center P of the bottle mouth portion x1 and the cap peripheral surface y1. In such a fourth shared camera 5D, the fourth shared camera 5D in which the fourth range R4 of + 225 ° to + 315 ° (−45 °) is reflected in the center around the center P of the bottle mouth portion x1 and the cap peripheral surface y1. An image is taken, and a fourth shared image signal indicating the fourth shared image is output to the arithmetic unit 3A.

Here, the above-mentioned first to fourth shared cameras 5A to 5D all emit visible light in the same manner as the first to fourth mouth cameras 1A to 1D and the cap camera 2 of the first embodiment. It is a camera in the imaging wavelength range. That is, the first to fourth shared cameras 5A to 5D are image pickup devices that capture the first to fourth shared images as visible images.

Further, such the first to fourth shared cameras 5A to 5D are arranged at positions facing the mouth mark x3 (first object mark) and the cap mark y3 (second object mark) to provide an external optical system. It is a camera that directly captures a mouth image (first object image) including a mouth mark x3 and a cap image (second object image) including a cap mark y3 without intervention.

The arithmetic unit 3A controls the first to fourth shared cameras 5A to 5D, and the first to fourth shared image signals and higher control devices input from the first to fourth shared cameras 5A to 5D, respectively. This is an evaluation means for calculating the winding angle θ of the cap Y (cover) with respect to the bottle body X (container) based on the external signal input from.

The arithmetic unit 3A is a kind of computer like the arithmetic unit 3 of the first embodiment, and is a storage unit for storing a predetermined inspection program or the like, and the first to fourth shared cameras 5A to 5D to the first to first. It is provided with an input / output unit that receives the shared image signal of 4 and outputs an inspection result to the display device 4, an arithmetic unit that executes an inspection program, and the like.

The arithmetic unit 3A acquires the first to fourth shared image signals for each of the plurality of PET bottles B1 sequentially transported to a predetermined inspection position by an external transport device, and these first to fourth shared images. The winding angle θ is sequentially calculated by processing the signal according to the above inspection program.

Further, the arithmetic unit 3A sequentially evaluates the winding tightening angle θ by sequentially comparing the winding tightening angle θ with a predetermined evaluation standard. Further, the arithmetic unit 3A sequentially outputs the evaluation result, that is, the inspection result of each PET bottle B1 to the display device 4 as an inspection signal. The display device 4 is a device that displays an image of the inspection result based on the inspection signals sequentially input from the arithmetic unit 3A. This display device 4 is the same device as that of the first embodiment, and corresponds to the output means of the present invention.

Next, the operation of the winding angle inspection device A1 according to the second embodiment will be described in detail with reference to the flowchart shown in FIG.

In the winding angle inspection device A1, when the PET bottle B is conveyed to the inspection position, an arrival signal (external signal) is input to the arithmetic unit 3A from the external host control device. Upon receiving this arrival signal, the arithmetic unit 3A instructs the first to fourth shared cameras 5A to 5D to take an image. As a result, the first to fourth shared cameras 5A to 5D capture the first to fourth shared images (step S1a).

Then, the arithmetic unit 3A acquires the first to fourth shared images as the first to fourth shared image signals. Then, the arithmetic unit 3A generates one composite image Gs as shown in FIG. 10 by performing the expansion process to the plane coordinate system and the mutual combination process on the first to fourth shared images. (Step S2a).

Here, since the bottle mouth portion x1 and the cap peripheral surface y1 have a cylindrical shape having a predetermined radius from the center P, the positions on the first to fourth shared images and the mouth portion peripheral surface x2 and the cap peripheral surface in the real space The position on y1 is deviated. This amount of deviation depends on the shape (size and curvature) of the bottle mouth portion x1 and the cap peripheral surface y1.

Therefore, in order to accurately evaluate the relative positions of the mouth mark x3 on the mouth peripheral surface x2 and the cap mark y4 on the cap peripheral surface y1 with respect to the reference angle (0 °), it is due to the shape of the bottle mouth portion x1. It is necessary to correct the misalignment of the cap mark y4 due to the shapes of the mouth mark x3 and the cap peripheral surface y1.

In the unfolding process, in order to correct such a positional deviation, an image (image of the curved coordinate system) of the bottle mouth portion x1 (mouth peripheral surface x2) curved with a predetermined curvature and an image of the cap peripheral surface y1 (image of the curved coordinate system) ( This is an image process for generating the first to fourth unfolded shared images by converting the coordinates (image of the curved coordinate system) into the image of the plane coordinate system. The combination processing is an image processing for generating one composite image Gs by connecting such first to fourth unfolded shared images in the order of angles around the center P of the bottle mouth portion x1 and the cap peripheral surface y1. be.

When the combination process is completed, the arithmetic unit 3A performs a feature extraction process related to the mouth image (step S3a). This feature extraction process is a process of extracting an image portion (mouth feature portion) having a shape similar to the mouth mark x3 from the composite image Gs. The arithmetic unit 3A extracts the mouth feature portion in the composite image Gs as a mouth mark candidate based on such a feature extraction process.

Although one or a plurality of such mouth mark candidates are extracted, the arithmetic unit 3A narrows down the mouth mark candidates to one by performing exclusive processing on the plurality of mouth mark candidates (step S4a). .. This exclusive processing is conditional on, for example, the size of the mouth mark candidate, and the mouth mark candidate that is extremely large with respect to the size of the mouth mark x3 is excluded.

Then, the arithmetic unit 3A performs a determination process of whether or not the mouth mark candidates narrowed down to one by the exclusive process can be specified as the mouth mark x3 (step S5a). In this determination process, the shape and size of the mouth mark candidate are evaluated again, and it is determined whether or not the mouth mark candidate is truly the mouth mark x3. Then, when the determination in step S5a is "Yes", the arithmetic unit 3A specifies the mouth mark candidate as the mouth mark x3.

Subsequently, when the result of the determination process in step S5a is “Yes”, the arithmetic unit 3A performs a feature extraction process related to the cap image (step S6a). This feature extraction process is a process of extracting an image portion (cap feature portion) having a shape similar to the cap mark y4 from the composite image Gs. The arithmetic unit 3A extracts the cap feature portion in the composite image Gs as a cap mark candidate based on such a feature extraction process.

Although one or a plurality of such cap mark candidates are extracted, the arithmetic unit 3A narrows down the cap mark candidates to one by performing exclusive processing on the plurality of cap mark candidates (step S7a). This exclusive processing is conditional on, for example, the size of the cap mark candidate, and the cap mark candidate extremely large with respect to the size of the cap mark y4 is excluded.

Then, the arithmetic unit 3A performs a determination process of whether or not the cap mark candidates narrowed down to one by the exclusive process can be specified as the cap mark y4 (step S8a). In this determination process, the shape and size of the cap mark candidate are evaluated again, and it is determined whether or not the cap mark candidate is truly the cap mark y4. Then, when the determination in step S8a is "Yes", the arithmetic unit 3A specifies the cap mark candidate as the cap mark y4.

When the arithmetic unit 3A specifies the mouth mark x3 and the cap mark y4 in this way, the arithmetic unit 3A performs a calculation process of the winding tightening angle θ (step S9a). In this calculation process, as shown in FIG. 10, the arithmetic unit 3 calculates the angle deviation θ ₁ of the mouth mark x3 with respect to the reference angle (0 °) in the composite image Gs as the first relative position.

Further, as shown in FIG. 10, the arithmetic unit 3A calculates the angle deviation θ ₂ of the cap mark y4 with respect to the reference angle (0 °) in the composite image Gs as the second relative position. Then, the arithmetic unit 3A calculates the difference (θ ₁ − θ _{2 ) between the angle deviation θ 1} and the angle deviation θ ₂ as the winding angle θ. That is, the arithmetic unit 3A calculates the winding angle θ based on the positional relationship between the first relative position and the second relative position.

Then, the arithmetic unit 3A determines whether or not the winding angle θ is within the range of the predetermined threshold value θref (step S10a). When the determination in step S10a is "Yes", the arithmetic unit 3A determines that the PET bottle B1 having the winding angle θ is acceptable (step S11a). If the determination in step S10a is "No", the arithmetic unit 3A determines that the PET bottle B1 having the winding angle θ is rejected (step S12a). Even when the determination in steps S5a and S8a described above is "No", the PET bottle B1 having the winding angle θ is determined to be unacceptable (step S12a).

As described above, the winding angle inspection device A1 according to the second embodiment uses the four shared cameras 5A to 5D arranged at predetermined intervals on the side of the PET bottle B1 to image the mouth (first object). Image) and cap image (second object image) are imaged. That is, the winding angle inspection device A1 has four shared cameras 5A provided on the sides of the PET bottle B1 at predetermined intervals with respect to the mouth mark x3 and the cap mark y4 that can be visually recognized from the side. It is equipped with ~ 5D.

According to such a winding angle inspection device A1, the winding angle θ of the PET bottle B1 is inspected using four shared cameras 5A to 5D, so that a special optical system lens (external optical system) as in the conventional case is used. ) Does not need to be used. Therefore, according to the second embodiment, it is possible to provide the winding angle inspection device A1 that does not use an external optical system other than the camera.

The present invention is not limited to the above embodiment, and for example, the following modifications can be considered.
(1) In the first and second embodiments, the PET bottles B and B1 are the objects to be inspected, but the present invention is not limited thereto. The present invention can be applied to various inspection objects in which a second object provided with a second mark is screwed to a first object provided with a first mark.

(2) In the first embodiment, the first to fourth mouth images (first object images) are obtained by providing four mouth cameras 1A to 1D, but the present invention is limited to this. Not done. The number of mouth cameras, that is, the number of first object images may be other than 4.

For example, the first object may be imaged by three mouth cameras by setting the angle division around the bottle mouth x 1 to 120 °. Further, when the possible value of the winding angle θ is limited to a relatively narrow angle range, the first object may be imaged by one mouth camera.

This also applies to the second embodiment. That is, instead of the four shared cameras 5A to 5D, the shared images (first and second object images) may be acquired by using a number of shared cameras other than the four.

(3) In the first and second embodiments, the first to fourth mouth cameras 1A to 1D, the cap camera 2 and the shared camera 5A that capture the mouth image, the cap image, and the shared image as visible images. ~ 5D is adopted, but the present invention is not limited to this.

That is, it is conceivable that the mouth mark x3 (first object mark) and / or the cap marks y3 and y4 (second object mark) are provided as invisible marks depending on the object to be inspected. As the invisible mark, a mark that can be imaged by an ultraviolet camera that is sensitive to an invisible wavelength band, for example, an ultraviolet wavelength band can be considered. For such an invisible mark, a camera capable of capturing the invisible mark, such as an ultraviolet camera, may be adopted.

(4) In the first and second embodiments, the display device 4 is adopted as the output means, but the present invention is not limited to this. For example, a storage device, a communication device, or an alarm device may be adopted as the output means.

(5) In the first and second embodiments, the PET bottles B and B1 are judged to pass when the winding angle θ is within the threshold value θref, but the present invention is not limited to this. In the pass / fail determination method in the present embodiment, pass determination is made when the winding angle θ is 360 ° or more more or less, that is, when the winding rotation speed of the cap Y is more than one rotation or less.

For such a problem, the dimension Lxy (distance indicating the positional relationship between the bottle body X and the cap Y in the vertical direction) shown in FIG. 3B is measured, and this dimension Lxy is within a predetermined evaluation value. It is conceivable to make a pass judgment if it is in. When the winding angle θ is more or less than 360 °, the dimension Lxy becomes a value significantly deviated from the original value. The dimension Lxy is, for example, the distance from the top surface y2 of the cap to the lower end of the neck ring portion provided with the mouth mark x3, or the distance from the bottom surface portion of the cap Y to the lower end of the neck ring portion.

(6) In the first and second embodiments, the cylindrical PET bottles B and B1 are the objects to be inspected, but the present invention is not limited thereto. The present invention is also applicable to an inspection object having a shape other than a cylindrical shape, for example, a polygonal inspection object.

A, A1 Winding angle inspection device B, B1 PET bottle (inspection target)
Gc cap image Gk combined image Gs composite image R1 1st range R2 2nd range R3 3rd range R4 4th range X Bottle body (1st object, container body)
x1 Bottle mouth x2 Mouth peripheral surface x3 Mouth mark (first object mark)
Y, Y1 cap (second object, lid)
y1 Cap peripheral surface y2 Cap top surface y3, y4 Cap mark (second object mark)
1A ~ 1D Mouth camera (camera)
2 Cap camera (camera)
3,3A arithmetic unit (evaluation means)
4 Display device (output means)
5A-5D shared camera (camera)

Claims (7)

Regarding the inspection target object in which the second object is screwed into the first object, the said with respect to the first object based on the first object mark provided on the first object and the second object mark provided on the second object. A winding angle inspection device that inspects the winding angle of a second object.
A plurality of cameras arranged at positions facing the first object mark and the second object mark and directly capturing a first object image including the first object mark and a second object image including the second object mark. ,
An evaluation means for calculating the winding angle θ based on the first object image and the second object image and evaluating the winding angle θ.
A winding angle inspection device comprising an output means for outputting an evaluation result of the evaluation means. When the first object is the container body and the first object mark is provided on the mouth of the container body.
The winding angle inspection device according to claim 1, wherein the camera is provided at a position facing the mouth portion. The winding angle inspection device according to claim 2, wherein the camera is provided around the mouth portion at a plurality of positions divided by a predetermined angle division. When the second object is a lid and the second object mark is provided on the top surface of the lid.
The winding angle inspection device according to any one of claims 1 to 3, wherein the camera is provided at a position facing the top surface of the lid. One of claims 1 to 4, wherein the camera captures a shared image in which a first object including the first object mark and a second object including the second object mark are simultaneously reflected. The winding angle inspection device described in the section. The evaluation means is
Based on the first object image, the relative position θ1 of the first object mark with respect to the reference position of the first object is detected.
Based on the second object image, the relative position θ2 of the second object mark with respect to the reference position of the first object is detected.
The winding angle inspection apparatus according to any one of claims 1 to 5, wherein the winding angle θ is calculated based on the positional relationship between the relative position θ1 and the relative position θ2. The winding angle inspection device according to any one of claims 1 to 6, wherein the inspection object is a PET bottle in which a cap is screwed into the mouth of the bottle body.

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