Printing equipment and printing method

Abstract

The present invention provides a printing apparatus and printing method that can accurately determine whether the distance from the end of a steel material to the first character falls within a predetermined distance range, and that can be implemented at low cost and by simple means. [Solution] The control device for the printing equipment controls the printing device to print multiple characters on the surface of the steel material while the printing device and imaging device are moving relative to the steel material, and controls the imaging device to capture an image of a region that includes at least the area from the end of the steel material to the first character, thereby generating an image. The control device also uses an image analysis model to detect the position of the end of the steel material in the image and an artificial intelligence model to detect the position of the first character in the image. Based on the results of each process, it derives the distance from the end of the steel material to the first character and determines whether that distance falls within a predetermined distance range.

Description

Technical Field

[0001] The present invention relates to printing equipment and a printing method.

Background Art

[0002] In the technical field of steel materials, in order to manage steel materials, a plurality of characters indicating, for example, a management number or the like may be printed on the surface of the steel material. For example, a steel material is placed on a transport mechanism of printing equipment, and while the steel material is being transported, a plurality of characters are printed on the surface of the steel material. Here, for example, due to a shift in the position of the steel material placed on the transport mechanism, the position of the first character located on the end side of the steel material among the plurality of characters may deviate from the range of the normal position. In such a case, it will not conform to the specifications required for the steel material as a regular product. Therefore, it is required to prevent the outflow of the steel material in which the position of the first character deviates from the range of the normal position. Also, it is desired to perform an inspection as to whether the position of the first character is within the range of the normal position by means of a full inspection rather than a sampling inspection. Further, it is desired that the inspection be realized by means of a low-cost and simple method. The inspection as to whether the position of the first character is within the range of the normal position can be realized by determining whether the distance from the end of the steel material to the first character is within a predetermined distance range.

[0003] Note that Patent Document 1 discloses an identification device for identifying characters displayed on the surface of a steel plate, which includes an imaging means for imaging an image including the characters on the surface of the steel plate, and a character recognition means for recognizing characters from the imaged image. The character recognition means includes an image processing unit for performing absolute or relative binarization processing on the image with a predetermined threshold value, a character cutting-out unit for discriminating a region where characters are described from the image binarized by the image processing unit and extracting a character image unit, a matching ratio acquisition unit for comparing the extracted character image unit with registered characters stored in advance and obtaining a matching ratio, and a character identification unit for determining a character as a recognized character represented by one of the registered characters having a matching ratio with the character image unit of a predetermined value or more.

[0004] Furthermore, Patent Document 2 discloses an identification device for identifying articles, comprising: an image acquisition unit that acquires one or more captured images of a region containing first information which is information displayed on an article; a recognition unit that recognizes at least one piece of first information based on the captured images acquired by the image acquisition unit; a comparison unit that compares at least a portion of the first recognition information which is the first information recognized by the recognition unit with first stored information which is the first information pre-stored in a storage medium as one of the stored information; and a specification unit that identifies at least one candidate article based on the result of the comparison by the comparison unit, wherein the comparison unit can compare recognition information which is partially different from the first recognition information with stored information which is pre-stored in the storage medium as information corresponding to the recognition information.

[0005] Furthermore, Patent Document 3 describes a method for determining the quality of white characters printed on the outer surface of a steel pipe in a steel pipe manufacturing line, and the area S (mm²) of the white area when predetermined characters are completely printed as a printing area for quality determination. 2 The following steps are taken: ) are determined in advance; a pass / fail judgment mark is printed on each individual steel pipe; the steel pipe with the pass / fail judgment mark is placed on a specific pass line with the pass / fail judgment mark facing upwards; a fixed camera positioned at a predetermined distance above the pass line and shooting downwards is used to photograph a predetermined area including the pass / fail judgment mark; and for each individual steel pipe, the projected area S of the white portion when the predetermined characters are completely printed is determined. p (mm 2 In addition to calculating the area S0 (mm²) of the white area photographed for the actual printed pass / fail judgment section, the area of ​​the white part of the printed section was also calculated. 2 ) is measured, and the projected area S of the white area when fully printed is measured. P The judgment index D(%) = 100 × S0 / S is expressed as the ratio of the area S0 of the captured white area to the total area. P A method for determining the quality of printing on the outer surface of a steel pipe is disclosed, characterized by calculating a judgment index D and then comparing the calculated judgment index D with a pre-set threshold to determine the quality of the printing.

[0006] Furthermore, Patent Document 4 discloses a character recognition device that recognizes characters displayed on the surface of an object, comprising: an imaging unit that captures images of the surface of an object and generates an image under conditions where the positional relationship with the object is not constant; and an arithmetic processing unit that recognizes characters displayed on the surface of the object based on the image. The arithmetic processing unit comprises: a first character recognition unit that performs character recognition based on the image; a line acquisition unit that acquires a line corresponding to the horizontal direction of the characters displayed on the surface of the object and a line corresponding to the vertical direction of the characters displayed on the surface of the object based on rectangular information recognized by the character recognition by the first character recognition unit; a frontal orientation transformation unit that generates a transformed image by transforming the image so that the characters displayed on the surface of the object are viewed from the front, based on the horizontal and vertical lines acquired by the line acquisition unit; and a second character recognition unit that performs character recognition based on the transformed image, and outputs the characters recognized by the second character recognition unit. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2024-46908 [Patent Document 2] International Publication No. 2022 / 092147 Brochure [Patent Document 3] Japanese Patent Publication No. 2009-245337 [Patent Document 4] Japanese Patent Publication No. 2023-143387 [Overview of the project] [Problems that the invention aims to solve]

[0008] The present invention aims to provide a printing apparatus and printing method that can accurately determine whether the distance from the end of a steel material to the first character falls within a predetermined distance range, and that can be implemented by low-cost and simple means. [Means for solving the problem]

[0009] A printing apparatus according to a first aspect of the present invention comprises a printing device for printing a plurality of characters on the surface of a steel material, an imaging device for imaging the surface of the steel material, a moving device for moving the printing device and the imaging device relative to the steel material, and a control device for controlling the printing device, the imaging device, and the moving device, wherein the control device includes a moving control unit that controls the moving device to move the printing device and the imaging device relative to the steel material, a printing control unit that controls the printing device to print the plurality of characters on the surface of the steel material while the printing device and the imaging device are moving relative to the steel material, and controls the imaging device to print the plurality of characters from the end of the steel material towards the end of the steel material. The system comprises: an imaging control unit that controls the system to capture an image of a region including at least the first character located therein to generate an image; a first detection processing unit that performs a process to detect the position of the end of the steel material in the image using an image analysis model that analyzes changes in brightness in the image; a second detection processing unit that performs a process to detect the position of the first character in the image using an artificial intelligence model that has learned the relationship between the image and the position of the first character in the image; a derivation processing unit that performs a process to derive the distance from the end of the steel material to the first character based on the detection results of the first detection processing unit and the detection results of the second detection processing unit; and a determination processing unit that performs a process to determine whether the distance derived by the derivation processing unit falls within a predetermined distance range.

[0010] A printing method according to a second aspect of the present invention uses a printing apparatus comprising: a printing device for printing a plurality of characters on the surface of a steel material; an imaging device for imaging the surface of the steel material; a moving device for moving the printing device and the imaging device relative to the steel material; and a control device for controlling the printing device, the imaging device, and the moving device, wherein the moving device performs a moving step in which the moving device moves the printing device and the imaging device relative to the steel material; a printing step in which the printing device prints the plurality of characters on the surface of the steel material while the printing device and the imaging device are moving relative to the steel material; and the imaging device, while the printing device and the imaging device are moving relative to the steel material, moves from the end of the steel material to the first character of the plurality of characters located on the end side of the steel material. The system includes: an imaging step of capturing an area including, but not necessarily, a region to generate an image; a first detection step in which the control device detects the position of the end of the steel material in the image using an image analysis model that analyzes changes in brightness in the image; a second detection step in which the control device detects the position of the first character in the image using an artificial intelligence model that has learned the relationship between the image and the position of the first character in the image; a derivation step in which the control device derives the distance from the end of the steel material to the first character based on the detection results of the first detection step and the detection results of the second detection step; and a determination step in which the control device determines whether the distance derived in the derivation step falls within a predetermined distance range. [Effects of the Invention]

[0011] The present invention provides a printing apparatus and printing method that can accurately determine whether the distance from the end of the steel material to the first character falls within a predetermined distance range, and that can be implemented by low-cost and simple means. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic plan view showing an example of a printing apparatus according to the first embodiment of the present invention. [Figure 2] It is a block diagram showing an example of the functional configuration of the control device according to the first embodiment of the present invention. [Figure 3] It is a diagram showing an example of a captured image. [Figure 4] It is a block diagram showing an example of the hardware configuration of the control device. [Figure 5] It is a flowchart showing an example of the flow of the printing method according to the first embodiment of the present invention. [Figure 6] It is a plan view schematically showing an example of the printing equipment according to the second embodiment of the present invention. [Figure 7] It is a block diagram showing an example of the functional configuration of the control device according to the second embodiment of the present invention.

Mode for Carrying Out the Invention

[0013] [First Embodiment] First, the printing equipment 10 according to the first embodiment of the present invention will be described.

[0014] FIG. 1 shows an example of the printing equipment 10 according to the first embodiment of the present invention. In addition to the function of printing a plurality of characters on the surface of the steel material 12, the printing equipment 10 has a function of determining whether the position of the character (hereinafter referred to as the "first character") located closest to the end 12A side of the steel material 12 among the plurality of characters is within the range of the normal position. The range of the normal position is preset according to the specifications required for the steel material 12 as a normal product. The steel material 12 to be printed by the printing equipment 10 may be any of a steel plate, a steel pipe, a shaped steel, a steel bar, etc. Hereinafter, the case where the steel material 12 is a steel pipe will be described as an example.

[0015] The printing equipment 10 includes a printing device 14, an imaging device 16, a conveying device 18, and a control device 20. The printing device 14 is a device that prints a plurality of characters indicating, for example, a management number or the like on the surface of the steel material 12. As the printing device 14, for example, a stencil machine or the like is used. The printing device 14 can simultaneously print characters on a plurality of steel materials 12 placed on a conveying mechanism 22 described later. The printing device 14 prints a plurality of characters along the conveying direction of the steel material 12 for each steel material 12. Hereinafter, the direction in which the printing device 14 prints a plurality of characters is referred to as the "printing direction". The imaging device 16 is a device that images the surface of the steel material 12. As the imaging device 16, for example, a digital camera or a CCD (Charge Coupled Device) camera or the like is used. The imaging device 16 is arranged on the downstream side in the conveying direction with respect to the printing device 14.

[0016] The conveying device 18 is a device that conveys the steel material 12 in the conveying direction. The conveying device 18 is an example of the "moving device" in the present invention. The conveying device 18 includes a conveying mechanism 22 and a driving mechanism (not shown). The conveying mechanism 22 has a size and structure capable of placing a plurality of steel materials 12. The conveying mechanism 22 is, for example, a belt conveyor. The driving mechanism is, for example, a motor driving mechanism, and by operating the conveying mechanism 22, a plurality of steel materials 12 are conveyed in the conveying direction. Each steel material 12 is in a long shape and is arranged along the conveying direction on the conveying mechanism 22. Further, a plurality of steel materials 12 are arranged side by side in a direction orthogonal to the conveying direction in a plan view. The control device 20 is a device that controls the printing device 14, the imaging device 16, and the conveying device 18, and is connected to the printing device 14, the imaging device 16, and the conveying device 18 by wire or wirelessly.

[0017] FIG. 2 shows an example of the functional configuration of the control device 20. The control device 20 includes, as a functional configuration, a conveyance control unit 30, a printing control unit 32, an imaging control unit 34, a first detection processing unit 36, a second detection processing unit 38, a derivation processing unit 40, a determination processing unit 42, and a storage unit 44. The control device 20 is a device that performs various controls and calculations related to the printing equipment 10, and is configured by a computer having a hardware configuration described later.

[0018] The transport control unit 30 controls the transport device 18 to transport multiple steel materials 12 in the transport direction. The transport control unit 30 is an example of a "movement control unit" in the present invention. The transport control unit 30 starts transporting when it receives a command to start transporting from an external source. The printing control unit 32 controls the printing device 14 to print multiple characters on the surface of each steel material 12 along the transport direction while the multiple steel materials 12 are being transported. The printing control unit 32 controls the printing device 14 to print multiple characters in an area located at a predetermined distance from the end 12A of the steel material 12. Note that the position of the first character may vary due to fluctuations in the transport speed, etc.

[0019] The imaging control unit 34 controls the imaging device 16 to image an area including at least the end 12A of the steel material 12 to the first character while multiple steel materials 12 are being transported, thereby generating an image 60. The imaging control unit 34 may generate multiple images 60 by having the imaging device 16 take continuous images, or it may generate a single image 60 by having the imaging device 16 take images while the area including at least the end 12A of the steel material 12 to the first character is included in the field of view of the imaging device 16. The imaging control unit 34 may also control the imaging device 16 to illuminate the image with its illuminator (not shown) when taking images. The control device 20 receives the image 60 from the imaging device 16. If the control device 20 receives multiple image 60 from the imaging device 16, it may combine the multiple image 60 to generate a single image 60.

[0020] Furthermore, the image analysis model 50, described later, detects the position of the end portion 12A of the steel material 12 within the captured image 60 by analyzing changes in brightness within the captured image 60. Therefore, the image capture control unit 34 controls the imaging device 16 in synchronization with the transport position of the steel material 12 so that the captured image 60 for detecting the position of the end portion 12A of the steel material 12 includes an image containing the background away from the end portion 12A of the steel material 12 in the transport direction, and an image containing the end portion 12A of the steel material 12, so that a change in brightness occurs within the captured image 60 with the end portion 12A of the steel material 12 as the boundary.

[0021] The first detection processing unit 36 ​​performs a process to detect the position of the end portion 12A of the steel material 12 in the captured image 60 using the image analysis model 50, which will be described later. The second detection processing unit 38 performs a process to detect the position of the first character in the captured image 60 using the artificial intelligence model 52, which will be described later. The image analysis model 50 and the artificial intelligence model 52 are stored in the storage unit 44.

[0022] The derivation processing unit 40 performs a process to derive the distance from the end 12A of the steel material 12 to the first character based on the detection results of the first detection processing unit 36 ​​and the detection results of the second detection processing unit 38. The distance from the end 12A of the steel material 12 to the first character (i.e., the actual distance) is derived based on, for example, the distance from the end 12A of the steel material 12 to the first character in the captured image 60, the focal length of the imaging device 16, and the distance from the imaging device 16 to the steel material 12. For example, in the case of multiple captured images 60, the distance from the end 12A of the steel material 12 to the first character is derived based on, for example, the position of the end 12A of the steel material 12 in the captured image 60 that includes the end 12A of the steel material 12, the number of captured images 60 from the end 12A of the steel material 12 to the first character, the amount of overlap of the multiple captured images 60, and the position of the first character in the captured image 60 that includes the first character.

[0023] The determination processing unit 42 performs a process to determine whether the distance derived by the derivation processing unit 40 falls within a predetermined distance range. The distance range is set according to the specifications required for the steel material 12 as a regular product. The determination result of the determination processing unit 42 may be displayed on a display (not shown) or stored in the storage unit 44. If the transport control unit 30 receives a good determination result from the determination processing unit 42, it continues transporting; if it receives a bad determination result, it stops transporting.

[0024] The image analysis model 50 is a computer program model that analyzes changes in brightness within the captured image 60, and is a non-learning model. The image analysis model 50 performs processes such as binarization and various filtering processes as part of the analysis of changes in brightness within the captured image 60. By analyzing changes in brightness within the captured image 60, the image analysis model 50 detects the position of the end 12A of the steel material 12 within the captured image 60. Since the brightness within the captured image 60 changes at the end 12A of the steel material 12, the position of the end 12A of the steel material 12 within the captured image 60 can be detected by analyzing changes in brightness within the captured image 60.

[0025] The artificial intelligence model 52 is a computer program model that has learned the relationship between captured images 60 and the position of the first character within those images 60, and is a learning model type. The artificial intelligence model 52 uses, for example, a neural network (specifically, a convolutional neural network such as YOLO). The artificial intelligence model 52 is constructed using, for example, a learning method such as deep learning, with training data consisting of captured images 60 for each of the multiple steel materials 12 used for training as input data, and the position of the first character within the input captured images 60 as output data. The input data uses multiple captured images 60 with different positions for the first character, assuming variations in transport speed.

[0026] Figure 3 shows an example of an image 60. Below, we will explain the processing of the artificial intelligence model 52 in more detail, using the example of a case where the letters "ABCDEFG" are printed as multiple characters on the surface of the steel material 12.

[0027] The artificial intelligence model 52 obtains rectangular information from the captured image 60, indicating the size and position of the rectangle corresponding to each of the multiple characters in the captured image 60, using, for example, a bounding box technique. Then, based on the rectangular information corresponding to each of the multiple characters, it detects the first character in the captured image 60, and based on the rectangular information corresponding to the first character, it detects the position of the first character in the captured image 60. In the example shown in Figure 3, the first character is "A". The position of the first character in the captured image 60 is derived, for example, based on the position of the rectangle (e.g., the center or corner of the rectangle) relative to a predetermined reference position (e.g., the center or corner of the captured image 60) for the captured image 60.

[0028] Figure 4 shows an example of the hardware configuration of the control device 20. The control device 20 is composed of a computer. The control device 20 includes a CPU (Central Processing Unit) 90, memory 92, storage device 94, input device 96, output device 98, storage medium reader 100, and communication I / F (Interface) 102. Each component is connected to the others so as to be able to communicate with each other via a bus 104.

[0029] The storage device 94 stores a program for performing surface condition inspection. The CPU 90 is a central processing unit that executes various programs and controls each component. Specifically, the CPU 90 reads the program from the storage device 94 and executes the program using memory 92 as a workspace. The CPU 90 controls each component and performs various calculations according to the program stored in the storage device 94.

[0030] Memory 92 is composed of RAM (Random Access Memory) and temporarily stores programs and data as a working area. Storage device 94 is composed of ROM (Read Only Memory), HDD (Hard Disk Drive), or SSD (Solid State Drive), etc., and stores various programs and data, including the operating system.

[0031] The input device 96 is a device for performing various types of input, such as a keyboard or mouse. The output device 98 is a device for outputting various types of information, such as a display or printer. A touch panel display may be used as the output device 98 and function as the input device 96.

[0032] The storage medium reader 100 reads data stored on various storage media such as CD (Compact Disc)-ROM, DVD (Digital Versatile Disc)-ROM, Blu-ray disc, or USB (Universal Serial Bus) memory, and writes data to the storage media. The communication I / F 102 is an interface for communicating with other devices. For example, the communication I / F 102 uses an interface that conforms to standards such as Ethernet (registered trademark), FDDI, or Wi-Fi (registered trademark).

[0033] Figure 5 shows an example of the flow of the printing method according to the first embodiment of the present invention. The printing method according to the first embodiment of the present invention is performed using the printing equipment 10 described above.

[0034] First, in step S1, the conveying device 18 starts a conveying step in which it conveys the steel material 12 in the conveying direction. The conveying step is an example of a "movement step" in the present invention.

[0035] Next, in step S2, while the steel material 12 is being transported in the transport direction, the printing device 14 performs a printing step in which it prints multiple characters on the surface of the steel material 12.

[0036] Next, in step S3, while the steel material 12 is being transported in the transport direction, the imaging device 16 performs an imaging step to generate an image 60 by imaging an area that includes at least the end 12A of the steel material 12 up to the first of a plurality of characters.

[0037] Next, in step S4, the control device 20 performs a first detection step in which it detects the position of the end portion 12A of the steel material 12 in the captured image 60 using an image analysis model 50 that analyzes changes in brightness in the captured image 60.

[0038] Next, in step S5, the control device 20 performs a second detection step in which it detects the position of the first character in the captured image 60 using an artificial intelligence model 52 that has learned the relationship between the captured image 60 and the position of the first character in the captured image 60.

[0039] Next, in step S6, the control device 20 performs a derivation step to derive the distance from the end 12A of the steel material 12 to the first letter, based on the detection results of the first detection step and the detection results of the second detection step.

[0040] Next, in step S7, the control device 20 performs a determination step to determine whether the distance derived in the derivation step falls within a predetermined distance range.

[0041] Next, in step S8, the control device 20 determines whether or not to terminate the transport. If the determination in step S7 is favorable, the control device 20 determines to continue the transport (step S8: NO) and executes the processes from step S2 to step S7 for the next steel material 12. On the other hand, if the determination in step S7 is unfavorable, the control device 20 stops the transport (step S8: YES) and terminates the printing method.

[0042] As described in detail above, in the first embodiment of the present invention, the derivation processing unit 40 performs a process to derive the distance from the end 12A of the steel material 12 to the first character based on the detection results of the first detection processing unit 36 ​​and the detection results of the second detection processing unit 38, and the determination processing unit 42 performs a process to determine whether the distance derived by the derivation processing unit 40 falls within a predetermined distance range. Here, the second detection processing unit 38 uses an artificial intelligence model 52 that has learned the relationship between the captured image 60 and the position of the first character in the captured image 60 to detect the position of the first character in the captured image 60. Therefore, compared to cases where, for example, pattern matching technology or OCR (Optical Character Recognition) technology is used to detect the position of the first character, the position of the first character can be detected with high accuracy even when the position of the first character varies. In other words, by including training data in the training data used to train the artificial intelligence model 52 that uses multiple captured images 60 with different positions for the first character as input data, taking into account variations in transport speed, the position of the first character can be detected with high accuracy even when the position of the first character varies. As a result, the distance from the end 12A of the steel material 12 to the first character can be derived with high accuracy, and the determination process of whether the distance derived by the derivation processing unit 40 falls within a predetermined distance range can be performed with high accuracy.

[0043] Furthermore, the first detection processing unit 36 ​​uses the image analysis model 50 to perform a process to detect the position of the end portion 12A of the steel material 12 within the captured image 60. Here, the image analysis model 50 is a computer program model that analyzes changes in brightness within the captured image 60, and is a non-learning model. Therefore, compared to the case where a learning model is used, the learning process (especially the annotation process) is unnecessary, so the determination process can be realized by low-cost and simple means.

[0044] [Second Embodiment] Next, a printing apparatus 10 according to a second embodiment of the present invention will be described.

[0045] Figure 6 shows an example of a printing apparatus 210 according to a second embodiment of the present invention. The printing apparatus 210 has the following configuration changes compared to the printing apparatus 10 according to the first embodiment described above. The following describes the configuration of the printing apparatus 210, which differs from the printing apparatus 10 according to the first embodiment described above.

[0046] The printing equipment 10 comprises a first imaging device 16A and a second imaging device 16B. The first imaging device 16A and the second imaging device 16B are examples of "imaging devices" in the present invention. The first imaging device 16A is positioned on one side of the printing direction relative to the printing device 14, and the second imaging device 16B is positioned on the other side of the printing direction relative to the printing device 14. The first imaging device 16A and the second imaging device 16B are fixed to the printing device 14.

[0047] The printing device 14 has a drive device 24. The drive device 24 is an example of a "moving device" in the present invention. The drive device 24 is, for example, a motor drive device that moves the printing device 14 to one side and the other side in the printing direction. When the printing device 14 moves, the first imaging device 16A and the second imaging device 16B move together with the printing device 14. The transport direction of the steel material 12 is set to a direction perpendicular to the printing direction. In the second embodiment, the steel material 12 is transported one by one in the transport direction by the transport device 18.

[0048] Figure 7 shows an example of the functional configuration of the control device 20. The control device 20 has the following functional configuration: a transport control unit 30, a drive control unit 46, a printing control unit 32, an imaging control unit 34, a first detection processing unit 36, a second detection processing unit 38, an output processing unit 40, a determination processing unit 42, and a storage unit 44.

[0049] The transport control unit 30 controls the transport device 18 to transport the steel material 12 in the transport direction. The drive control unit 46 controls the drive device 24 to move the printing device 14 to one side and the other side in the printing direction. By controlling the drive device 24, the drive control unit 46 causes the drive device 24 to perform a movement step that moves the printing device 14, the first imaging device 16A, and the second imaging device 16B in the printing direction. While the transport of the steel material 12 is stopped, the printing control unit 32 controls the printing device 14 to print multiple characters on the surface of the steel material 12 while the printing device 14 is moving. For the first steel material 12, the printing control unit 32 controls the printing device 14 to move from one side to the other side in the printing direction on the steel material 12, and for the second steel material 12, it controls the printing device 14 to move from the other side to the one side in the printing direction. From this point onward, the printing control unit 32 switches between controlling the printing device 14 to move to one side of the printing direction and controlling it to move to the other side each time the steel material 12 on which the characters are printed is replaced.

[0050] The imaging control unit 34 controls the first imaging device 16A to image an area including at least the area from the end 12A of the steel material 12 to the first character while the printing device 14 is moving from one side to the other in the printing direction on the steel material 12, in order to generate an image 60. The imaging control unit 34 also controls the second imaging device 16B to image an area including at least the area from the end 12A of the steel material 12 to the first character while the printing device 14 is moving from the other side to the one side in the printing direction on the steel material 12, in order to generate an image 60. The operation of the first detection processing unit 36, the second detection processing unit 38, the derivation processing unit 40, and the determination processing unit 42 is the same as in the first embodiment.

[0051] In the second embodiment described above, as in the first embodiment, the determination process of whether the distance from the end of the steel material to the first character falls within a predetermined distance range can be performed with high accuracy and can be realized by low-cost and simple means.

[0052] Although the first and second embodiments of the present invention have been described above, the present invention is not limited to those described above, and it is of course possible to implement it in various modified forms without departing from the spirit of the invention. [Explanation of Symbols]

[0053] 10 Printing equipment 12 Steel material 12A End of steel material 14 Printing device 16 Imaging device 16A First Imaging Device 16B Second Imaging Device 18 Conveying device 20 Control device 22 Conveying mechanism 24 Drive unit 30 Transport Control Unit 32 Printing Control Unit 34 Imaging Control Unit 36 First Detection Processing Unit 38 Second detection processing unit 40 Derivation Processing Unit 42. Determination Processing Unit 44 Storage section 46 Drive control unit 50 Image Analysis Models 52 Artificial Intelligence Models 60 captured images 90 CPU 92 memory 94 Storage device 96 Input device 98 Output device 100 Storage medium reader 102 Communication I / F 104 Bus 210 Printing equipment

Claims

1. A printing device that prints multiple characters on the surface of a steel material, An imaging device for imaging the surface of the steel material, A moving device for moving the printing device and the imaging device relative to the steel material, A control device for controlling the printing device, the imaging device, and the moving device, Equipped with, The control device is The moving device includes a movement control unit that controls the relative movement of the printing device and the imaging device with respect to the steel material, A printing control unit controls the printing device to print the plurality of characters on the surface of the steel material while the printing device and the imaging device are moving relative to the steel material, While the printing device and the imaging device are moving relative to the steel material, the imaging control unit controls the imaging device to image a region that includes at least the area from the end of the steel material to the first character among the plurality of characters located on the end side of the steel material, in order to generate an image; A first detection processing unit performs a process to detect the position of the end of the steel material in the captured image using an image analysis model that analyzes changes in brightness in the captured image. A second detection processing unit performs a process to detect the position of the first character in the captured image using an artificial intelligence model that has learned the relationship between the captured image and the position of the first character in the captured image. A derivation processing unit performs a process to derive the distance from the end of the steel material to the first character based on the detection result of the first detection processing unit and the detection result of the second detection processing unit, A determination processing unit performs a process to determine whether the distance derived by the derivation processing unit falls within a predetermined distance range, Printing equipment equipped with the following features.

2. A printing device that prints multiple characters on the surface of a steel material, An imaging device for imaging the surface of the steel material, A moving device for moving the printing device and the imaging device relative to the steel material, A control device for controlling the printing device, the imaging device, and the moving device, Using printing equipment equipped with, The moving device includes a moving step of moving the printing device and the imaging device relative to the steel material, The printing step involves printing the plurality of characters on the surface of the steel material while the printing device and the imaging device are moving relative to the steel material, The imaging step involves the imaging device capturing an image of a region including at least the area from the end of the steel material to the first character among the plurality of characters located on the end side of the steel material, while the imaging device and the printing device are moving relative to the steel material, thereby generating an image. The control device performs a first detection step in which it detects the position of the end of the steel material in the captured image using an image analysis model that analyzes changes in brightness in the captured image, The control device performs a second detection step in which it detects the position of the first character in the captured image using an artificial intelligence model that has learned the relationship between the captured image and the position of the first character in the captured image, The control device performs a derivation step of deriving the distance from the end of the steel material to the first character based on the detection result of the first detection step and the detection result of the second detection step, The control device includes a determination step that determines whether the distance derived by the derivation step falls within a predetermined distance range, A printing method comprising the following features.

Images