Marking reading device for metal formed products, management system for metal formed products, and marking reading method for metal formed products

Abstract

To provide a marking reading device, a management system, and a marking reading method, capable of improving the reading rate of a marking indicated on a metal molding.SOLUTION: A reading unit 50 includes: a first illumination device 51a that irradiates a can bottom portion 6a with light; a reader that captures an image of a marking M in synchronization with the irradiation timing of the first illumination device 51a; a second illumination device 52a that irradiates the can bottom portion 6a with light from a direction different from that of the first illumination device 51a in a state where the surface of the can bottom portion 6a is viewed from a normal direction; and a reader that captures an image of the marking in synchronization with the irradiation timing of the second illumination device 52a.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a marking reading device, a management system, and a marking reading method for a metal molded product manufactured from a rolled material.

Background Art

[0002] Conventionally, in order to clearly image the markings shown on the surface of a metal rolled material, there has been a device that images the surface of the rolled material while illuminating it from a direction parallel to the rolling direction (for example, Patent Document 1). However, it is extremely difficult to store, transport, etc. a metal molded product formed from a rolled material so that the rolling direction is in a fixed direction. For this reason, with conventional devices, a clear captured image of a metal molded product could not be stably obtained.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a marking reading device, a management system, and a marking reading method capable of clearly imaging the markings shown on a metal molded product manufactured from a rolled material.

Means for Solving the Problems

[0005] One aspect of the present invention is a marking reading device for markings shown on a marking formation part on the surface of a metal formed product manufactured from a rolled metal plate, comprising: a first illumination unit that irradiates light onto the marking formation part; a first imaging unit that images the markings in synchronization with the irradiation timing of the first illumination unit; a second illumination unit that irradiates light from a direction different from that of the first illumination unit onto the marking formation part in a state where the marking formation part is viewed from the normal direction; a second imaging unit that images the markings in synchronization with the irradiation timing of the second illumination unit. 、In a state where the marking formation portion of the metal molded product disposed at the reading position is viewed from the normal direction, the angle θ formed by the irradiation direction of the first illumination unit and the irradiation direction of the second illumination unit is such that 20 degrees < θ < 160 degrees A marking reading device for a metal formed product, characterized by the above. One aspect of the present invention is, for example, a marking reading device for markings shown on a marking formation portion on the surface of a metal molded product manufactured from a rolled metal plate, comprising: a first illumination unit that irradiates light onto the marking formation portion; a first imaging unit that images the marking in synchronization with the irradiation timing of the first illumination unit; a second illumination unit that irradiates light onto the marking formation portion from a direction different from that of the first illumination unit in a state where the marking formation portion of the metal molded product disposed at the reading position is viewed from the normal direction; and a second imaging unit that images the marking in synchronization with the irradiation timing of the second illumination unit. The marking has encoded information, and in a state where the marking formation portion of the metal molded product disposed at the reading position is viewed from the normal direction, the angle formed by the irradiation direction of the first illumination unit and the irradiation direction of the second illumination unit is such that the marking can be decoded based on at least one of the imaging information acquired by the first imaging unit and the imaging information acquired by the second imaging unit. A marking reading device for a metal molded product is characterized by this. One aspect of the present invention is a marking reading method for markings shown on a marking formation part on the surface of a metal formed product manufactured from a rolled metal plate, comprising: a first illumination step of irradiating light onto the marking formation part; a first imaging step of imaging the markings in synchronization with the irradiation timing of the first illumination step; a second illumination step of irradiating light from a direction different from that of the first illumination step onto the marking formation part in a state where the marking formation part is viewed from the normal direction; a second imaging step of imaging the markings in synchronization with the irradiation timing of the second illumination step. 、In a state where the marking formation portion of the metal molded product disposed at the reading position is viewed from the normal direction, the angle θ formed by the irradiation direction of the light in the first illumination step and the irradiation direction of the light in the second illumination step is such that 20 degrees < θ < 160 degrees A marking reading method for a metal formed product, characterized by the above. One aspect of the present invention is a method for reading a marking shown on a marking formation part on the surface of a metal formed product manufactured from, for example, a rolled metal plate. The method includes a first illumination step of irradiating light to the marking formation part, a first imaging step of imaging the marking in synchronization with the irradiation timing of the first illumination step, a second illumination step of irradiating light to the marking formation part from a direction different from that of the first illumination step in a state where the marking formation part is viewed from the normal direction, and a second imaging step of imaging the marking in synchronization with the irradiation timing of the second illumination step. The marking has encoded information, and in a state where the marking formation part of the metal formed product arranged at the reading position is viewed from the normal direction, the angle formed by the irradiation direction of the light in the first illumination step and the irradiation direction of the light in the second illumination step is such that the marking can be decoded based on at least one of the imaging information obtained in the first imaging step and the imaging information obtained in the second imaging step. This is a method for reading a marking on a metal formed product.

Brief Description of the Drawings

[0006]

Figure 1

Figure 2

Figure 3

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Figure 6

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Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0007] (Embodiment) Hereinafter, embodiments of the present invention will be described with reference to the drawings and the like. FIG. 1 is a diagram for explaining the configuration of the can 6 management system 1 of the embodiment. FIG. 2 is a diagram for explaining the stored information in the process history storage unit 25b of the embodiment. As shown in FIG. 1, the management system 1 is a system for manufacturing a can 6 (a metal molded product, a metal molded can) from a rolled material of a metal (such as aluminum, steel, etc.) and a system for managing the process history of the manufactured can 6. The can 6 manufactured by the management system 1 is an empty can. In the embodiment, a two-piece can will be described as an example. Note that in the embodiment, the can 6 is not limited to a completed product, and includes an intermediate body processed into the can 6 (for example, an intermediate body after a capping press process, etc.). The can 6 is provided with a rim 6b on the bottom of the can 6a (see FIG. 5(C) etc.). The rim 6b is a protrusion provided in an annular range at the periphery of the bottom part 6a of the can, as viewed in the axial direction of the can. The rim 6b bulges downward in the axial direction of the can from this annular range. The management system 1 includes a manufacturing system 10 (a can manufacturing system) and a management device 25.

[0008] (Manufacturing system 10) The manufacturing system 10 is a system provided on the manufacturing line in the manufacturing factory of the can 6. The manufacturing system 10 includes a capping press device 21, a can body processing device 22, a printing device 23, and an inspection device 24. Communication is possible between the capping press device 21, the can body processing device 22, the printing device 23, the inspection device 24, and the management device 25 via a communication network 2 such as a LAN. In the configuration where the management device 25 is provided in a management facility outside the manufacturing factory, cloud computing, etc., the communication network 2 may include a line such as the Internet.

[0009] In the embodiment, the computer refers to a device including an electronic computer equipped with a storage device, a control device, an arithmetic device, etc. The capping press device 21, the can body processing device 22, the printing device 23, the inspection device 24, the management device 25, and the reading units 50, 60, 70 each include a storage unit, a control unit, etc., and are included in the concept of a computer. Also, each device is not limited to a form configured by a single electronic computer, and may be configured by a plurality of electronic computers as necessary. The storage unit is a storage device such as a hard disk or a semiconductor memory element for storing programs, information, etc. necessary for the operation of each device. The control unit is a device for performing arithmetic processing necessary for the operation of each device and for comprehensively controlling each device. The control unit is composed of, for example, a CPU (Central Processing Unit), etc. The control unit realizes various functions of the embodiment by appropriately reading and executing various programs stored in the storage unit.

[0010] The capping press device 21, the can body processing device 22, the printing device 23, and the inspection device 24 are arranged in this order from the upstream side to the downstream side of the manufacturing line. The capping press device 21, the can body processing device 22, the printing device 23, and the inspection device 24 each include a reading unit 21b, 22b, 23b, 24b and a control unit 21i, 22i, 23i, 24i.

[0011] As will be described later, the reading units 21b, 22b, 23b, 24b are devices that read the marking M on the bottom of the can 6 within each process. In each process, when processing etc. is performed in a plurality of lanes, the reading units may be respectively arranged in each lane, or one reading unit may read the marking M of the cans 6 that are processed etc. in a plurality of lanes.

[0012] In the latter case, for example, after one reading unit reads the marking M of the can 6 upstream of the lane, it suffices to grasp which of the plurality of lanes the read can 6 has moved to. For example, in the case where can body processing devices 22 are respectively arranged in a plurality of lanes in the can body processing process, one reading unit may be arranged upstream of the lane. Also, it suffices to enable communication between this one reading unit and the sorting device that sorts the cans 6 into lanes. Then, the reading unit may be able to obtain information from the sorting device about which lane the can 6 with the marking M read has been conveyed to.

[0013] The capping press device 21 is a device that executes the capping process. Although illustration is omitted, the capping press device 21 includes a press working machine etc. and performs punching, drawing, etc. In punching, the rolled material 5 drawn from the roll is punched into a disk shape using a punching die. In drawing, the rolled material 5 punched into a disk shape is drawn and formed into a cup shape using a mold (die, punch, etc.). In drawing, according to the type of the can 6, the bottom part 6a of the can is formed into a dome shape, a flat shape, or the like. In the embodiment, the drawing in the capping process is also referred to as cup processing as appropriate, and the cup-shaped member processed from the rolled material 5 is also referred to as a metal cup.

[0014] The capping press device 21 includes a marking device 21a. The marking device 21a is a device that prints or engraves a marking M in the range where the bottom part 6a of the can 6 is formed. The marking device 21a is, for example, an inkjet printer, a laser marker, or the like. The marking device 21a may print or engrave the marking M in the range of the rolled material 5 that is to be processed into the bottom part 6a of the can after punching and before cup processing, or may also print or engrave the marking M on the bottom part 6a of the metal cup manufactured by cup-processing the rolled material 5. The marking M is a display including can identification information, which is identification information capable of identifying the can 6. As the can identification information, for example, a serial number of numbers, symbols, or the like can be used. The marking M is a display encoding the can identification information. In the embodiment, an example is described in which the marking M is a two-dimensional code having information encoding information including the can identification information, but it is not limited thereto. For example, it may be a one-dimensional code, or may be the can identification information itself (numbers, symbols, etc.). The can identification information may be issued by the marking device 21a. Alternatively, the management device 25 may issue the can identification information, and the marking device 21a may acquire this can identification information.

[0015] The can body processing device 22 is a device that executes a can body processing step (also referred to as a body maker step). Although illustration is omitted, the can body processing device 22 includes a processing device or the like that performs ironing on the metal cup. In ironing, using an ironing die, the can body part is thinned in the can axis direction.

[0016] The printing device 23 is a device that executes the printing process. The printing device 23 includes a blanket 23f that transfers ink to the can body, a burnish roller 23h that applies burnish, etc. (see Fig. 9).

[0017] The inspection device 24 is a device that executes the inspection process. The inspection device 24 includes a camera that acquires a captured image of the can 6. The inspection device 24 can determine the quality of the can 6 (e.g., appearance inspection, dimensional inspection, etc.) by performing image analysis on this captured image. The inspection device 24 determines whether the quality of the appearance of the can 6 is OK (qualified) or NG (unqualified) based on this quality result.

[0018] The control units 21i, 22i, 23i, and 24i of the above respective devices associate the can identification information obtained by decoding the marking M read by the inspection device 24 with the manufacturing information of the can 6 as can identification information - manufacturing information, and output it to the management device 25. The manufacturing information is information related to the manufacturing facilities of each device (see Fig. 2). The manufacturing information of each device is the following information. Capping press device 21: Punching die numbers 1 to 5 Can body processing device 22: Lane numbers 1 to 5 Printing device 23: Blanket numbers 1 to 5 Inspection device 24: Inspection results NG, OK

[0019] Note that the manufacturing information is not limited to the above information. For example, it may be information such as processing date and time, processing conditions of each device (e.g., press pressure, feed speed during printing, temperature of various processing fluids, etc.), or it may include two or more pieces of information.

[0020] (Management device 25) The management device 25 is a device that manages the manufacturing history of the can 6. The management device 25 is a device such as a server or a personal computer. The management device 25 includes a storage unit 25a and a control unit 25i. The memory unit 25a includes a process history memory unit 25b. As shown in FIG. 2, the process history memory unit 25b stores by associating can identification information and manufacturing information. Based on the can identification information - manufacturing information output from each device, the control unit 25i performs processes such as storing and managing the manufacturing history in the process history memory unit 25b. The manufacturing history is the history of manufacturing information in the manufacturing process of the can 6. For example, for the can 6 with the marking M having "can identification information = 0001", the marking M is read by each reading unit of the capping press device 21, the can body processing device 22, the printing device 23, and the inspection device 24. Then, each device outputs the can identification information - manufacturing information having "can identification information = 0001" to the management device 25. Based on the transmission of the can identification information - manufacturing information from each device, the control unit 25i of the management device 25 associates "can identification information = 0001" with the manufacturing information of each device and sequentially stores it in the process history memory unit 25b. Thereby, the management device 25 can store and manage the manufacturing history of the can 6 with the marking M having "can identification information = 0001".

[0021] Here, the conveyance order of the plurality of cans 6 in the manufacturing process is irregular. For this reason, for example, in the capping press process, even if the can 6 with "can identification information = 0001" finishes processing earlier than the can 6 with "can identification information = 0002", in the can body processing process, the can 6 with "can identification information = 0002" may be processed earlier than the can 6 with "can identification information = 0001". For this reason, the manufacturing history of the can 6 cannot be managed based on the manufactured order.

[0022] In contrast, in the embodiment, based on the can identification information - manufacturing information output from each device, the manufacturing history can be stored and managed. For this reason, the manufacturing information of each can 6 can be traced based on the can identification information. Thereby, the management system 1 can manage the manufacturing information of the can 6 on the manufacturing line, the can 6 after shipment, etc. based on the can identification information of the can 6.

[0023] [Relationship between irradiation angle and captured image] Here, the relationship between the irradiation angle θ30 of the illumination device 30 that irradiates the bottom of the can with illumination light when reading the marking M and the captured image of the bottom portion 6a of the can will be described. FIG. 3 is a diagram for explaining the mode in which the light L30 of the illumination device 30 of the embodiment is reflected on the surface of the metal rolling material 5. In the embodiment, in a state where the surface of the metal rolling material 5 is viewed from the normal direction, the angle formed by the optical axis of the illumination light of the illumination device and the rolling direction RD of the rolling material 5 is also referred to as the irradiation angle θ30. Also, the probability that the reading unit can decode the captured image of the marking M is also referred to as the reading rate.

[0024] As shown in FIG. 3, the surface of the metal rolling material 5 has a plurality of streaks along the rolling direction RD which is a single direction. These streaks are formed by grooves with a minute depth. When the light L30 emitted by the illumination device 30 reaches the metal surface, it is diffusely reflected by these grooves. As shown in FIG. 3(A), the amount of light diffusely reflected on the metal surface among the light L30 of the illumination device 30 increases as the irradiation angle θ30 approaches 90 degrees. As shown in FIG. 3(B), the amount of light specularly reflected on the metal surface among the light L30 of the illumination device 30 increases as the irradiation angle θ30 approaches 0 degrees (that is, as the optical axis of the illumination device 30 and the rolling direction RD approach parallel). That is, as the irradiation angle θ30 approaches 0 degrees, the amount of diffusely reflected light decreases.

[0025] (Verification of the captured image of the marking M) FIG. 4 is a diagram for explaining the verification result in which the captured image of the bottom portion 6a of the can of the embodiment changes according to the irradiation angle θ30. FIG. 4 schematically illustrates the captured image. For reference, FIG. 4 also shows the irradiation angle θ30 of an obtuse angle exceeding 90 degrees, but basically, if the absolute value of the difference between the irradiation angle θ30 and 90 degrees (|θ30 - 90 degrees|) is the same, the conditions are the same for an acute angle and an obtuse angle with respect to the irradiation angle θ30. For example, as shown in the parentheses in FIG. 4, the irradiation angle θ30 = 100 degrees and the irradiation angle θ30 = 80 degrees are the same conditions.

[0026] In the verification, the marking M was engraved on the center of the bottom 6a of the aluminum can 6 with a laser marker, and the bottom 6a of the can was irradiated at a plurality of irradiation angles θ30. The shape of the bottom 6a of the can is dome-shaped. Among the bottom 6a of the can, the portion where the marking M is engraved (marking formation portion) is within a range where it can be regarded as a plane orthogonal to the can axis. The incident angle of the light L30 on the bottom 6a of the can (the angle formed by the optical axis of the illumination light and the normal of the surface of the bottom 6a of the can) was set to 45 degrees. Then, imaging was performed from directly above the bottom 6a of the can with a reader, and it was verified whether the can identification information could be decoded from the captured image of the marking M. As shown in FIG. 4, in the captured image of the marking M on the bottom 6a of the can, as the irradiation angle θ30 approaches 90 degrees, the influence of specular reflection increases, and the contrast between the marking M and the exposed portion of the metal surface decreases. On the other hand, as the irradiation angle θ30 approaches 0 degrees, the contrast between the marking M and the exposed portion of the metal surface increases.

[0027] Also, when the irradiation angle θ30 was 80 degrees, 90 degrees, or 100 degrees, the can identification information could not be decoded due to the blurred captured image of the marking M. On the other hand, when the irradiation angle θ30 was 0 degrees, 60 degrees, 70 degrees, and 110 degrees, 120 degrees, 130 degrees, since the captured image of the marking M was clear, the can identification information could be decoded. From these results, it was confirmed that when the irradiation angle θ30 is 80 degrees or more and 100 degrees or less, the can identification information cannot be decoded due to the blurred captured image of the marking M. On the other hand, when the irradiation angle θ30 is 70 degrees or less and 110 degrees or more, it was confirmed that the can identification information can be decoded because the captured image of the marking M is clear.

[0028] That is, in this verification, it was confirmed that the state in which decoding based on the marking M is most difficult is the state where the irradiation angle θ30 is 90 degrees. Also, it was confirmed that the reading rate of the marking M improves as the irradiation angle θ30 moves away from this state with the state where the irradiation angle θ30 is 90 degrees as the center.

[0029] [Reading units 50, 60, 70] Details of the reading units 50, 60, and 70 will be described. (Reading unit 50 (basic configuration)) FIG. 5 is a three-view drawing for explaining the reading unit 50 of the embodiment. FIG. 5(A) is a view of FIG. 5(B) seen from the left side (in FIG. 5(B), among the directions orthogonal to the can axis, the direction seen from the side of the first lighting device 51a). FIG. 5(B) is a view showing the reading unit 50 in a state where the surface of the bottom 6a of the can 6 arranged at the reading position is seen from the lower side in the can axis direction. FIG. 5(C) is a view of FIG. 5(B) seen from the lower side (in FIG. 5(B), among the directions orthogonal to the can axis, the direction seen from the side of the second lighting device 52a). FIG. 6 is a diagram for explaining the light collection by the condenser lens 53 of the embodiment and the reflection of light at the rim 6b of the bottom 6a of the can, and is an enlarged view of a part of FIG. 5(C). In the drawings, the illustration of the can 6 shows only the surface (outer contour surface) of the can 6 as appropriate, and the illustration of the thickness portion of the can 6 is omitted. Further, in the embodiment, the normal direction of the apex portion of the dome of the bottom 6a of the can (the surface of the bottom 6a of the can) and the can axis direction (the direction of the central axis of the can 6) coincide. The state of viewing the normal direction of the apex portion of the dome of the bottom 6a of the can and the state of viewing from the can axis direction (the direction of the central axis of the can 6) are the same.

[0030] The reading unit 50 is the basic configuration of the reading unit of the embodiment. The reading unit 50 includes a first lighting device 51a, a second lighting device 52a, a reader 55 (one imaging unit), and a control unit 59. The first lighting device 51a, the second lighting device 52a, and the reader 55 are fixed around the can 6 arranged at the reading position by fixing members (not shown) such as brackets and stays. The first lighting device 51a and the second lighting device 52a are devices that irradiate illumination lights L51a and L52a onto the bottom 6a of the can, respectively. The first lighting device 51a is installed such that the optical axis (the central axis of the light beam of the illumination light L51a) faces the center of the surface of the bottom of the can 6a (that is, the top of the dome). Further, the incident angle θ50a of the illumination light L51a of the first lighting device 51a on the surface of the bottom of the can 6a is set to an illuminance at which the marking M can be decoded, for example, 40 degrees or more and 55 degrees or less. Note that if the incident angle θ50a is too small, although the illuminance increases, scattered reflected light due to rolling is likely to enter. On the other hand, if the incident angle is too large, the light to the installation range of the marking M is blocked by the rim 6b.

[0031] As shown in FIG. 6, the first lighting device 51a includes a condenser lens 53. The condenser lens 53 is an optical member that condenses the illumination light L51a (see the hatching shown in FIG. 6) emitted by the first lighting device 51a inside the rim 6b of the bottom of the can 6a. The condenser lens 53 may be provided inside the first lighting device 51a or may be provided outside the first lighting device 51a. The height h51a of the first lighting device 51a (the distance between the light-emitting portion of the first lighting device 51a and the top of the bottom of the can 6a) is, for example, about 15 mm or more.

[0032] Here, the bottom of the can 6a includes a rim 6b that contacts the ground surface. The rim 6b is provided so as to protrude downward in the can axis direction from the range of the outer edge portion of the bottom of the can 6a. The light L51d (see the dotted line) that reaches the rim 6b travels toward the inside of the bottom of the can 6a after being reflected on the surface of the rim 6b. In this way, the reflected light that travels toward the inside of the bottom of the can 6a excessively increases the illuminance of the bottom of the can 6a or is reflected on the surface of the bottom of the can 6a. Therefore, such reflected light is a factor that causes the captured image of the marking M to become unclear. Note that the amount of such reflected light is larger in the case of regular reflection than in the case of scattered reflection. For this reason, the captured image of the marking M is more likely to be affected by the reflected light at the rim 6b as the irradiation angle becomes smaller (that is, as the optical axis of the illumination light L51a of the first lighting device 51a approaches parallel to the rolling direction when viewed from the can axis direction).

[0033] The light-collecting lens 53 can sufficiently reduce the component of the light reaching the rim 6b by collecting the illumination light L51a of the first illumination device 51a inside the rim 6b, so that this reflected light can be reduced. As a result, the reading unit 50 can suppress the blurring of the captured image of the marking M and improve the reading rate. Note that FIG. 6 illustrates a mode in which the entire illumination light L51a is collected inside the rim 6b. However, it is only necessary to be able to collect the light L51d that is about to reach the inner surface of the rim 6b (specifically, the portion of the inner surface of the rim 6b facing the first illumination device 51a) inside the rim 6b. That is, the light L51e (see the dotted line) that reaches the outer surface of the rim 6b (the portion of the outer surface of the rim 6b facing the first illumination device 51a) basically reflects outward of the rim 6b.

[0034] The second illumination device 52a is the same device as the first illumination device 51a. That is, the direction of the optical axis of the second illumination device 52a faces the center of the bottom 6a of the can. Also, the incident angle of the illumination light of the second illumination device 52a on the bottom 6a of the can, the installation height of the second illumination device 52a, etc. are the same as those of the first illumination device 51a. Further, the second illumination device 52a includes a light-collecting lens (not shown). Also, as shown in FIG. 5(B), in the state viewed from the can axis direction, the optical axis of the illumination light L51a of the first illumination device 51a and the optical axis of the illumination light L52a of the second illumination device 52a are orthogonal, that is, the angle θ50b formed by both optical axes is a right angle.

[0035] The reader 55 is a device having the function of a camera that acquires a captured image of the bottom 6a of the can. The optical axis O55 of the reader 55 (the optical axis of the optical lens of the reader 55) preferably coincides with the can axis direction. Thereby, when the marking M is provided near the dome-shaped top of the bottom 6a of the can, the distortion of the captured image of the marking M can be reduced. However, as long as the distortion of the captured image is sufficiently small and the image of the marking M can be decoded, such as the readers 71b, 72b, etc. described later, due to reasons such as the installation space of the reader, the optical axis of the reader may be slightly inclined with respect to the can axis. The installation height h55 of the reader 55 (the distance between the light-incident part of the reader 55 and the top of the bottom part 6a of the can) is, for example, about 200 mm.

[0036] With the above configuration, the control unit 59 acquires imaging information of the bottom part 6a of the can by controlling the reader 55 at the timing when the illumination of the first illumination device 51a is turned on (first illumination step) (first imaging step). Further, after turning off the illumination of the first illumination device 51a, the control unit 59 acquires imaging information of the bottom part 6a of the can by controlling the reader 55 at the timing when the illumination of the second illumination device 52a is turned on (second illumination step) (second imaging step). Then, the control unit 59 executes a process for decoding the marking M and acquiring can identification information based on these two pieces of imaging information.

[0037] As described above, in a state viewed from the can axis direction, the angle θ50b formed by the optical axis of the illumination light L51a and the optical axis of the illumination light L52a is 90 degrees. For this reason, even when decoding based on one piece of imaging information cannot be performed, the probability that decoding based on the other piece of imaging information is possible is extremely high. This is because even when the irradiation angle θ30 of one illumination device is within the range of 80 degrees ≤ θ30 ≤ 100 degrees, the irradiation angle θ30 of the other illumination device is within the range of 0 degrees ≤ θ30 < 80 degrees or 100 degrees < θ30 ≤ 180 degrees (see FIG. 4). That is, more specifically, when the irradiation angle θ30 of one illumination device is within the range of 80 degrees ≤ θ30 ≤ 100 degrees, the irradiation angle θ30 of the other illumination device is within the range of 0 degrees ≤ θ30 ≤ 10 degrees or 170 degrees ≤ θ30 ≤ 180 degrees. Further, even when the irradiation angle θ30 of one illumination device is within the range of 70 degrees < θ30 < 110 degrees, the irradiation angle θ30 of the other illumination device is within the range of 0 degrees ≤ θ30 < 20 degrees or 160 degrees < θ30 ≤ 180 degrees. Referring to the verification results in FIG. 4 and the like, in order to improve the reading rate of the marking M, it is not limited to θ50b = 90 degrees, and it is preferably 20 degrees < θ50b < 160 degrees, and more preferably 40 degrees ≤ θ50b ≤ 140 degrees.

[0038] (Reading units 60, 70) The reading units can have various configurations corresponding to the state of the can 6 to be read. That is, in the manufacturing process, the can 6 rotates around the can axis or moves for conveyance or the like. The reading unit can take various configurations according to the state of such a can 6. The basic configuration for the reading units 60, 70 to image the bottom of the can 6a is the same as that of the reading unit 50. For example, the installation heights of the respective lighting devices and the respective readers of the reading units 60, 70 are the same as those of the lighting devices 51a, 52a and the reader 55 of the reading unit 50. Also, the incident angles of the respective lighting devices of the reading units 60, 70 to the bottom of the can 6a are the same as the incident angles of the lighting devices 51a, 52a of the reading unit 50 to the bottom of the can 6a. In the state seen from the can axis direction, the optical axes of the respective first lighting devices and the optical axes of the respective second lighting devices are orthogonal.

[0039] (Reading unit 60, inspection device 24) The reading unit 60 has a configuration suitable for reading the marking M in a state where the can 6 does not rotate around the can axis and is moving (moving in a direction orthogonal to the can axis). In the embodiment, an example in which the reading unit 60 is provided in the inspection device 24 will be described. FIGS. 7 and 8 are three - view drawings for explaining the reading unit 60 of the embodiment. FIGS. 7 and 8 show an example in which the reading unit 60 is installed in the vicinity of the transport wheel 24d of the inspection device 24 as the reading unit 24b (see FIG. 1). FIG. 7 shows a state where the can 6 is disposed at the first position P61. FIGS. 7(A) to 7(C) respectively correspond to the directions shown in FIGS. 5(A) to 5(C). FIG. 8 shows a state where the can 6 is disposed at the second position P62 due to the transport wheel 24d rotating from the state of FIG. 7. FIG. 8(A) is a view seen from the left side of the tangent line B (a tangent line of the arc that is the movement locus of the center of the can 6 and passes through the center of the can 6 disposed at the second position P62) of FIG. 8(B). Figure 8(B) is a diagram showing the reading unit 60 in a state where the can 6 arranged at the second position P62 is viewed from the lower side in the can axis direction. Figure 8(C) is a diagram viewed from the outside in the radial direction C (the direction of a straight line passing through the center of the can 6 arranged at the second position P62 among the diameters of the conveying wheel 24d) of Figure 8(B). In addition, in FIGS. 7(A) and 8(A), the illustration of the first reader 61b is omitted.

[0040] As shown in FIG. 7, the inspection device 24 includes a conveying wheel 24d. The conveying wheel 24d is a member such as a disk shape or a column shape. The outer peripheral portion of the conveying wheel 24d has a plurality of arc-shaped notches 24e (also referred to as pockets or the like). The can 6 is accommodated in these notches 24e, and as the conveying wheel 24d rotates around the central axis (refer to the arrow θ24d), the can 6 moves along the outer peripheral portion of the conveying wheel 24d (refer to the arrow A24d). Note that the shape of the notch 24e may be an arc shape that opens widely outward in the radial direction. The conveying wheel 24d of the inspection device 24 is provided with a suction device (not shown) that sucks the accommodated can 6 and holds it in the notch 24e. Thereby, the conveying wheel 24d of the inspection device 24 moves the can 6 accommodated in the notch 24e without rotating it around the can axis.

[0041] The reading unit 60 includes a first unit 61, a second unit 62, and a control unit 69. The first unit 61 reads the marking M on the bottom 6a of the can 6 in a state where the can 6 is arranged at the first position P61. The second unit 62 reads the marking M on the bottom 6a of the can 6 in a state where the can 6 is arranged at the second position P62. The second position P62 is a position rotated by several degrees along the circumferential direction from the first position P61 (refer to FIG. 8). That is, when the can 6 passes through the first position P61, the first unit 61 images the marking M. After that, as the can 6 moves along the outer peripheral portion from the first position P61 and passes through the second position P62, the second unit 62 images the marking M. The first position P61 and the second position P62 may be spaced apart so that the first reader 61b and the second reader 62b described later do not interfere with each other.

[0042] The first unit 61 includes a first lighting device 61a and a first reader 61b (first imaging unit). As shown in FIG. 7(B), in the state viewed from the can axis direction, the optical axis of the illumination light L61a of the first lighting device 61a faces the center of the can 6 disposed at the first position P61, and is the tangential direction of the arc (see the arc-shaped arrow A24d) which is the movement locus of the center of the can 6. As shown in FIG. 7(C), the optical axis O61b of the first reader 61b coincides with the can axis direction of the can 6 disposed at the first position P61.

[0043] The second unit 62 includes a second lighting device 62a and a second reader 62b (second imaging unit). As shown in FIG. 8(A), the optical axis O62b of the second reader 62b coincides with the can axis direction of the can 6 disposed at the second position P62. Also, the direction of the optical axis of the illumination light L62a faces the center of the bottom 6a of the can 6 disposed at the second position P62, and is the normal direction (that is, the radial direction C) of the arc which is the movement locus of the center of the can 6 in the state viewed from the can axis direction. Thus, the second lighting device 62a and the second reader 62b are installed in accordance with the arrangement of the can 6 after moving to the second position P62. Thereby, the second unit 62 can read the marking M in a mode in which the movement of the can 6 accompanying the rotation of the conveying wheel 24d is corrected.

[0044] As shown in FIG. 7(C) and the like, when the can 6 passes through the first position P61, the control unit 69 controls the first lighting device 61a to irradiate the bottom 6a of the can with the illumination light L61a (first lighting step). Further, the control unit 69 controls the first reader 61b in synchronization with the control of the first lighting device 61a, and acquires an imaging image of the bottom 6a of the can in a state where the first lighting device 61a illuminates the bottom 6a of the can (first imaging step). Then, the control unit 69 turns off the illumination of the first lighting device 61a until the can 6 moves from the first position P61 to the second position P62.

[0045] As shown in FIG. 8(A) and the like, thereafter, when the can 6 passes through the second position P62, the control unit 69 controls the second lighting device 62a to irradiate the bottom portion 6a of the can with the illumination light L62a (second lighting step). Further, the control unit 69 controls the second reader 62b in synchronization with the control of the second lighting device 62a, and acquires an imaging image of the bottom portion 6a of the can in a state where the second lighting device 62a is illuminating the bottom portion 6a of the can (second imaging step). Then, the control unit 69 turns off the illumination of the second lighting device 62a until the next can 6 moves to the first position P61.

[0046] Thereby, the control unit 69 of the reading unit 60 can acquire the can identification information by the decoding process after acquiring the imaging information of the marking M from the first reader 61b and the second reader 62b in a state where the can 6 is disposed at the first position P61 and the second position P62. Then, when the can identification information can be acquired from both the imaging information of the first reader 61b and the imaging information of the second reader 62b, the control unit 69 may output the can identification information acquired by at least one of them to the control unit 24i of the inspection device 24. Further, when the can identification information can be acquired only from one of the imaging information of the first reader 61b and the imaging information of the second reader 62b, the control unit 69 may output the can identification information acquired only from one of them to the control unit 24i of the inspection device 24.

[0047] The control unit 24i of the inspection device 24 associates the can identification information acquired from the reading unit 60 with the inspection result (OK or NG) of the can 6 and outputs the result to the management device 25.

[0048] (Reading unit 70, printing device 23) The reading unit 70 has a configuration suitable for reading the marking M in a state where the can 6 is rotating around the can axis and moving. In the embodiment, an example in which the reading unit 70 is provided in the vicinity of the printing device 23 will be described. FIG. 9 is a diagram showing an example in which the reading unit 70 of the embodiment is attached to the mandrel wheel 23d of the printing device 23 as the reading unit 23b (see FIG. 1). FIG. 10 is a diagram showing an enlarged configuration near the reading unit 70 of the embodiment. The directions of the illustrations in FIGS. 10(A) to 10(C) respectively correspond to the directions of the illustrations in FIGS. 5(A) to 5(C).

[0049] As shown in FIG. 9, the printing device 23 includes a mandrel wheel 23d, a blanket 23f, and a burnish roller 23h. Although not shown, the printing device 23 includes a configuration such as a plate cylinder that adheres ink to the blanket 23f. The mandrel wheel 23d rotates around the central axis (see arrow θ23d), and the can 6 held by the mandrel 23e moves along a circumference centered on the central axis (see arrow A23d). As will be described later, in the printing process, the can 6 held by the mandrel 23e rotates around the can axis.

[0050] The blanket 23f is a plate for printing on the outer peripheral surface of the can body in a state where the can 6 is held by the mandrel 23e. In FIG. 9, the blanket numbers are shown in parentheses attached to the reference numerals of the blankets 23f. Five blankets 23f (23f(1) to 23f(5)) are fixed along the circumferential direction on the outer peripheral surface of the cylindrical blanket roller 23g. The blanket roller 23g rotates around the central axis (see arrow θ23g), and each blanket 23f transfers ink to the outer peripheral surface of the can body portion of the can 6. Accordingly, the can 6 rotates around the can axis (see arrow θ1). The burnish roller 23h is a device that applies a burnish for protecting the outer peripheral surface of the can 6 to the outer peripheral surface of the can 6 after printing. The burnish adheres to the outer peripheral surface of the burnish roller 23h. The burnish roller 23h rotates in the same manner as the blanket roller 23g (see arrow θ23h) to apply the burnish to the outer peripheral surface of the can body. Accordingly, the can 6 rotates around the can axis (see arrow θ2).

[0051] The reading unit 70 reads the marking M on the bottom portion 6a of the can 6 after the burnish is applied. Therefore, the reading position P70 of the reading unit 70 is a position where the can 6 after applying the burnish moves along a circumference centered on the central axis of the mandrel wheel 23d.

[0052] The reading unit 70 includes a first unit 71 and a second unit 72. The imaging operation of the second unit 72 is executed after the imaging operation of the first unit 71. However, the period between the two imaging operations is sufficiently short (for example, 1 / 100 second or less). Therefore, during the period between the two imaging operations, the rotational angle of the can 6 around its can axis is, for example, 10 degrees or less, and the moving distance of the can 6 is negligibly small. In the embodiment, the first unit 71 and the second unit 72 are considered to acquire imaging images with the can 6 arranged at the same position. That is, the position where the can 6 is arranged when the first unit 71 and the second unit 72 image the bottom of the can 6a is regarded as the reading position P70.

[0053] The first unit 71 includes a first lighting device 71a and a first reader 71b (first imaging unit). The optical axis of the first lighting device 71a is the same as the optical axis of the first lighting device 61a. That is, in a state viewed from the can axis direction, it faces the center of the can 6 arranged at the reading position P70, and is in the tangential direction of the arc (see the arc-shaped arrow A23d) which is the movement locus of the center of the can 6. The first reader 71b is arranged in the space above the bottom of the can 6a arranged at the reading position P70 so as to be able to image the bottom of the can 6a. The optical axis O71b of the first reader 71b passes through the center of the bottom of the can 6a arranged at the reading position P70. Also, the optical axis O71b of the first reader 71b does not coincide with the can axis direction, that is, it is arranged slightly inclined with respect to the can axis 6d (see Fig. 10(A)).

[0054] The second unit 72 includes a second lighting device 72a and a second reader 72b (second imaging unit). The configuration of the second lighting device 72a is the same as that of the second lighting device 62a. However, in a state viewed from the axial direction of the can, the optical axis of the illumination light L72a of the second lighting device 72a and the optical axis of the illumination light L71a of the first lighting device 71a are orthogonal (see Fig. 10(B)).

[0055] As shown in Figs. 9 and 10(B), in a state viewed from the axial direction of the can, the first reader 71b and the second reader 72b are arranged side by side in the radial direction of the mandrel wheel 23d. As shown in Fig. 10(A), in a state viewed from a direction orthogonal to the can axis (the tangential direction of a circle centered on the central axis of the mandrel wheel 23d), the first reader 71b and the second reader 72b are arranged at the same height. For this reason, the distance between the first reader 71b and the bottom of the can 6a is equal to the distance between the second reader 72b and the bottom of the can 6a. Further, the first reader 71b and the second reader 72b are arranged to be line-symmetric with the can axis 6d as the axis of symmetry. The angle formed by the optical axis O71b of the second reader 72b and the can axis 6d is equal to the angle formed by the optical axis O72b of the second reader 72b and the can axis 6d, and is, for example, about 5 to 10 degrees.

[0056] In this way, the first reader 71b and the second reader 72b are arranged with a slight shift in the radial direction, so that they can be arranged without interference even at the same height. Thereby, the first reader 71b and the second reader 72b can image the bottom of the can 6a in a state where the can 6 is arranged at the same position. The first reader 71b and the second reader 72b image the marking M on the bottom of the can 6a with an inclination of about 5 to 10 degrees from the can axis. The distortion of the captured image due to this degree of inclination hardly affects the decoding of the marking M.

[0057] As shown in FIG. 10(C), when the can 6 passes through the reading position P70, the control unit 79 controls the first lighting device 71a to irradiate the bottom portion 6a of the can with the illumination light L71a (first lighting step). Further, the control unit 79 controls the first reader 71b in synchronization with the control of the first lighting device 71a, and acquires a captured image of the bottom portion 6a of the can in a state where the first lighting device 71a is illuminating the bottom portion 6a of the can (first imaging step). The control unit 79 controls to turn off the illumination of the first lighting device 71a within 1 / 100 second or the like after starting the illumination of the first lighting device 71a.

[0058] As shown in FIG. 10(A), thereafter, the control unit 79 controls the illumination of the second lighting device 72a to irradiate the bottom portion 6a of the can with the illumination light L72a (second lighting step). Further, the control unit 79 controls the second reader 72b in synchronization with the control of the second lighting device 72a, and acquires a captured image of the bottom portion 6a of the can in a state where the second lighting device 72a is illuminating the bottom portion 6a of the can (second imaging step). Then, the control unit 79 turns off the illumination of the second lighting device 72a until the next can 6 moves to the reading position P70.

[0059] Thereby, the control unit 79 of the reading unit 70 can acquire the can identification information by the decoding process after acquiring the imaging information of the marking M from the first reader 71b and the second reader 72b in a state where the can 6 is arranged at the same position. And the control unit 79 may output the can identification information acquired at least by one of the imaging information of the first reader 71b and the imaging information of the second reader 72b to the control unit 23i of the printing device 23 in the same manner as the control unit 69 of the reading unit 60 when the can identification information can be acquired in both of them. Also, when the can identification information can be acquired only by one of the imaging information of the first reader 71b and the imaging information of the second reader 72b, the can identification information acquired only by one of them may be output to the control unit 23i of the printing device 23.

[0060] Here, during the period between the timing at which the first reader 71b acquires imaging information and the timing at which the second reader 72b acquires imaging information, the can 6 held by the mandrel 23e rotates around the can axis by inertia as the burnish roller 23h rotates. This period is within 1 / 100 second or the like. Therefore, the rotation angle of the can 6 during this period is within 10 degrees or the like. Also, in a state viewed from the can axis direction, the angle formed by the optical axis of the first lighting device 71a and the optical axis of the second lighting device 72a is 90 degrees. Therefore, even if the irradiation angle θ30 (see FIG. 4) of one of the first lighting device 71a and the lighting device 72a is 80 degrees or more and 100 degrees or less (that is, |θ30 - 90 degrees| ≤ 10 degrees), the irradiation angle θ30 of the other will be less than 80 degrees or greater than 100 degrees. That is, as described above, when the irradiation angle θ30 of one lighting device is within the range of 80 degrees ≤ θ30 ≤ 100 degrees, the irradiation angle θ30 of the other lighting device will be within the range of 0 degrees ≤ θ30 ≤ 10 degrees or 170 degrees ≤ θ30 ≤ 180 degrees. In this case, even if the can 6 rotates by about 10 degrees by inertia, the irradiation angle θ30 of the other will be within the range of 0 degrees ≤ θ30 ≤ 20 degrees or 160 degrees ≤ θ30 ≤ 180 degrees (that is, 20 degrees ≤ |θ30 - 90 degrees|). Thereby, the control unit 79 can improve the probability of being able to decode the marking M based on the imaging image of the other of the first reader 71b and the second reader 72b.

[0061] The control unit 23i of the printing device 23 associates the can identification information, the blanket number (1 to 5), and the plate number of the printing plate (not shown) acquired from the reading unit 70 and outputs them to the management device 25. Note that the control unit 79 can determine the number of the mandrel 23e that held the can 6 during printing of each can 6, the blanket numbers 1 to 5, and the plate number of the printing plate by a detection unit such as an encoder. Also, the control unit 23i can determine which of the plurality of mandrels 23e is located at the printing position, the reading position, etc. Therefore, the control unit 23i can associate the blanket numbers 1 to 5 with the can identification information acquired based on the imaging information of the can 6 arranged at the reading position.

[0062] As described above, the reading units 60 and 70 are attached to the inspection device 24 and the printing device 23. However, the reading unit can have various configurations according to the manufacturing device to which it is attached. For example, for a manufacturing device in which the can 6 does not rotate around the can axis and does not move the can 6, the reading unit attached thereto may have the same configuration as the reading unit 50 (see FIG. 5) which is the basic configuration. In this case, the bottom 6a of the can 6 where the first lighting device 51a and the second lighting device 52a are arranged at the same position is sequentially irradiated (first lighting step, second lighting step), and the reader 55 may capture an image of the bottom 6a of the can at the irradiation timing of each of the first lighting device 51a and the second lighting device 52a (first imaging step, second imaging step).

[0063] Also, in a manufacturing device (such as the printing device 23 etc.) in which the can 6 rotates around the can axis and the can 6 moves, the first lighting device may irradiate light of a first wavelength, and the second lighting device may irradiate light of a second wavelength which is different from the first wavelength. In this case, the first lighting device and the second lighting device may simultaneously irradiate the can 6 arranged at the same position with light of the first wavelength and light of the second wavelength (first lighting step, second lighting step). In this case, the first reader may be a device capable of capturing an image of the light of the first wavelength reflected by the bottom 6a of the can, and the second reader may be a device capable of capturing an image of the light of the second wavelength reflected by the bottom 6a of the can. Then, the first reader and the second reader may capture an image of the bottom 6a of the can at the same irradiation timing of the first lighting device and the second lighting device (first imaging step, second imaging step).

[0064] Note that when the reader is a device capable of independently capturing images of light of the first wavelength and light of the second wavelength, one reader may also serve as the first reader and the second reader. In this case, the reader may be, for example, a configuration capable of acquiring a plurality of captured images by continuously capturing images in one imaging operation, or a configuration including a half mirror or the like that splits the subject light.

[0065] As described above, the reading unit of the present embodiment can improve the reading rate of the marking M shown on the bottom 6a of the can 6 in the manufacturing process.

[0066] The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications and changes, such as the modified forms described later, are possible and are also within the technical scope of the present invention. Further, the effects described in the embodiments are merely an enumeration of the most suitable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments. Note that the configurations of the above-described embodiments and the modified forms described later can be used by using only a part thereof or by appropriately combining them, but detailed description thereof is omitted.

[0067] (Modified Form) (1) In the embodiment, an example in which the manufacturing system includes a capping press device, a can body processing device, a printing device, and an inspection device is shown, but the present invention is not limited thereto. The manufacturing system may include various devices for manufacturing cans (for example, a cleaning device, a neck processing device that performs drawing processing on the opening edge of the can, etc.). Further, the reading unit may be provided in a device that fills an empty can with a beverage or the like.

[0068] (2) In the embodiment, an example in which the angle formed by the optical axis of the first illumination device and the optical axis of the second illumination device is 90 degrees when viewed in the can axis direction is shown, but the present invention is not limited thereto. This formed angle may be such that can identification information can be decoded based on the imaging image acquired by the other when can identification information cannot be decoded based on the marking included in the imaging image acquired by one of the two readers. That is, this formed angle may be such that can identification information can be decoded based on at least one of the two imaging images acquired by the two readers.

[0069] (3) In the embodiment, an example in which the marking is formed by laser marking or by printing ink is shown, but the present invention is not limited thereto. The marking may be formed, for example, by attaching a seal. In addition, in the case of a metal-formed can or the like on which paint is applied in the spraying process, the contrast of printing will decrease. Although the marking formed by laser marking is susceptible to the influence of paint, the method of the embodiment is less susceptible to diffused light caused by illumination compared to, for example, ring illumination. As a result, even for a marking formed by laser marking, it is possible to suppress a decrease in the reading rate after the application of paint. (4) In the embodiment, an example where the can is conveyed on the circumference is shown, but it is not limited thereto. The can may be conveyed, for example, on a straight line.

[0070] (5) In the embodiment, an example where the illumination device includes a condenser lens is shown, but it is not limited thereto. For example, if the configuration is such that the rim does not block the light of the illumination device, such as when the distance between the illumination device and the bottom of the can is sufficiently small, the illumination device may not include a condenser lens. On the other hand, if the configuration is such that the rim blocks the light of the illumination device, such as when the distance between the illumination device and the bottom of the can is large, the illumination device may include a condenser lens.

[0071] (6) In the embodiment, an example where the marking formation part (the part where the marking is formed) is the bottom of the metal-formed can is shown, but it is not limited thereto. The marking formation part is the surface of the metal-formed can and is not limited as long as it is within the range that can be imaged by the reading unit. For example, it may be the circumferential surface of the can body, the upper surface of the can lid, or the like. Also, the marking read by the reading unit is not limited to the marking formed on the metal-formed can, and may be a marking formed on other metal-formed products manufactured by forming a metal rolling material (which may involve predetermined movement and rotation). Furthermore, the shape of the metal-formed can is not limited to a cylindrical shape, and may be approximately cylindrical (including those with an elliptical cross-sectional shape), or may have a circular or approximately circular cross-sectional shape (including an elliptical shape).

Description of Reference Numerals

[0072] 1: Management system 6: Can 6a: Bottom of can 6b: Rim 21b, 22b, 23b, 24b, 50, 60, 70: Reading unit 30: Lighting device 51a, 61a, 71a: First lighting device 52a, 62a, 72a: Second lighting device 53: Condensing lens 55: Reader 61, 71: First unit 61b, 71b: First reader 62, 72: Second unit 62b, 72b: Second reader M: Marking

Claims

1. A marking reading device for markings shown on a marking formation part on the surface of a metal formed product manufactured from a rolled metal plate, comprising: a first illumination unit that irradiates light onto the marking formation part; a first imaging unit that images the marking in synchronization with the irradiation timing of the first illumination unit; a second illumination unit that irradiates light onto the marking formation part from a direction different from that of the first illumination unit in a state where the marking formation part is viewed from the normal direction; a second imaging unit that images the marking in synchronization with the irradiation timing of the second illumination unit; in a state where the marking formation part of the metal formed product arranged at the reading position is viewed from the normal direction, the angle θ formed by the irradiation direction of the first illumination unit and the irradiation direction of the second illumination unit is 20 degrees < θ < 160 degrees A marking reading device for a metal formed product, characterized in that.

2. A marking reading device for markings shown on a marking formation part on the surface of a metal formed product manufactured from a rolled metal plate, comprising: a first illumination unit that irradiates light onto the marking formation part; a first imaging unit that images the marking in synchronization with the irradiation timing of the first illumination unit; a second illumination unit that irradiates light onto the marking formation part from a direction different from that of the first illumination unit in a state where the marking formation part is viewed from the normal direction; a second imaging unit that images the marking in synchronization with the irradiation timing of the second illumination unit; the marking has encoded information; in a state where the marking formation part of the metal formed product arranged at the reading position is viewed from the normal direction, the angle formed by the irradiation direction of the first illumination unit and the irradiation direction of the second illumination unit is such that the marking can be decoded based on at least one of the imaging information acquired by the first imaging unit and the imaging information acquired by the second imaging unit A marking reading device for a metal formed product, characterized in that.

3. The cross-sectional shape of the metal formed product is substantially circular The marking reading device for a metal formed product according to claim 1 or 2, characterized in that.

4. The metal formed product is substantially cylindrical The marking reading device for a metal formed product according to claim 1 or 2, characterized in that.

5. The metal formed product is a metal formed can, The marking formation part is the bottom of the metal formed can The marking reading device for a metal formed product according to claim 1 or 2, characterized in that.

6. The marking reading device is a device that images the marking of the marking formation unit in a state where the metal formed product is disposed at the first position and a second position moved from the first position. In a state where the metal formed product is disposed at the first position, the first illumination unit is disposed at a position that irradiates light to the marking formation unit, and the first imaging unit is disposed at a position that images the marking. In a state where the metal formed product is disposed at the second position, the second illumination unit is disposed at a position that irradiates light to the marking formation unit, and the second imaging unit is disposed at a position that images the marking. The marking reading device for a metal formed product according to claim 1 or 2, characterized in that.

7. The marking reading device is a device that images the marking of the marking formation unit in a state where the metal formed product is stationary. The first illumination unit and the second illumination unit irradiate light to the marking formation unit at different timings. The first imaging unit and the second imaging unit share one imaging unit. The one imaging unit images the marking at the irradiation timings of the first illumination unit and the second illumination unit, respectively. The marking reading device for a metal formed product according to claim 1 or 2, characterized in that.

8. The marking reading device is a device that images the marking of the marking formation unit in a state where the metal formed product is rotating and in a state where the metal formed product is disposed at a first position and a second position moved from the first position. The first position and the second position are small enough that the separation distance can be approximated to the same position. The rotational movement amount of the metal formed product between the first position and the second position is sufficiently small. In a state where the metal formed product is disposed at the first position, the first illumination unit is disposed at a position that irradiates light to the marking formation unit, and the first imaging unit is disposed at a position that images the marking. In a state where the metal formed product is disposed at the second position, the second illumination unit is disposed at a position that irradiates light to the marking formation unit, and the second imaging unit is disposed at a position that images the marking. The marking reading device for a metal formed product according to claim 1 or 2, characterized in that.

9. The marking reading device is a device that images the marking of the marking formation unit while the metal molded product is rotating and while the metal molded product is moving. The first illumination unit irradiates light of a first wavelength. The second illumination unit irradiates light of a second wavelength, which is different from the first wavelength, at the same timing as the first illumination unit. The first imaging unit reads the marking based on the intensity of light corresponding to the first wavelength. The second imaging unit images the marking based on the intensity of light corresponding to the second wavelength. The marking reading device for a metal molded product according to claim 1 or 2, characterized in that.

10. The bottom of the metal forming can is provided with a protrusion protruding downward in an annular range, and the marking is provided on a surface inside the annular range. The first illumination unit and the second illumination unit condense illumination light inside the annular range. The marking reading device for a metal molded product according to claim 5, characterized in that.

11. Executing a process of manufacturing the metal molded product, a plurality of processing devices of different types, and The marking reading device for a metal molded product according to claim 1 or 2 provided in each of the plurality of processing devices, and A management device capable of communicating with each of the processing devices, the management system for the metal molded product comprising: The marking has identification information of the metal molded product. Each of the processing devices Associates the reading information of the marking acquired by each of the marking reading devices with the processing information and outputs the same to the management device. The management device A storage unit, A control unit that executes a process of associating the identification information of each metal molded product with the processing information of the plurality of types of processing devices based on the outputs of the plurality of processing devices and storing the same in the storage unit. The management system for the metal molded product, characterized in that.

12. A marking reading method for a marking shown on a marking formation unit on the surface of a metal molded product manufactured from a rolled metal plate, comprising: A first illumination step of irradiating light to the marking formation unit; A first imaging step of imaging the marking in synchronization with the irradiation timing of the first illumination step; A second illumination step of irradiating light to the marking formation unit from a direction different from the first illumination step in a state where the marking formation unit is viewed from the normal direction. A second imaging step of imaging the marking in synchronization with the irradiation timing of the second lighting step; In a state where the marking formation part of the metal molded product arranged at the reading position is viewed from the normal direction, the angle θ formed by the irradiation direction of the light of the first lighting step and the irradiation direction of the light of the second lighting step is 20 degrees < θ < 160 degrees A method for reading a marking on a metal molded product, characterized by this.

13. A method for reading a marking shown on a marking formation part on the surface of a metal molded product manufactured from a rolled metal plate, comprising: A first lighting step of irradiating light to the marking formation part; A first imaging step of imaging the marking in synchronization with the irradiation timing of the first lighting step; A second lighting step of irradiating light to the marking formation part from a direction different from that of the first lighting step in a state where the marking formation part is viewed from the normal direction; A second imaging step of imaging the marking in synchronization with the irradiation timing of the second lighting step; The marking has encoded information; In a state where the marking formation part of the metal molded product arranged at the reading position is viewed from the normal direction, the angle formed by the irradiation direction of the light of the first lighting step and the irradiation direction of the light of the second lighting step is such that the marking can be decoded based on at least one of the imaging information obtained in the first imaging step and the imaging information obtained in the second imaging step. A method for reading a marking on a metal molded product, characterized by this.

Images