Code information printing system, printing control device, and medium

Abstract

A label management system (100) is for printing, in each step, code information (9) in a code region (2) which is provided on a substrate and on which the code information (9) can be printed, the system having: a printing data management unit (27) for generating new code information (9) to be printed in a unprinted region, on which the code information has not yet been printed, in the code region 2; a data storage means (14) for storing data included in code information (9); a printing apparatus (80) for printing the code information (9) on the substrate; and a label data reference device (50) for reading the printed code information (9). At least a part of the code information (9) is printed by using invisible ink that is formed from a near infrared absorbing material.

Description

Code information printing system, print control device and medium

[0001] The present invention relates to a code information printing system, a print control device, and a medium.

[0002] BACKGROUND ART For the purpose of ensuring the security of documents and the like or embedding additional data, a technology is known in which characters and the like are printed using invisible ink made of a near-infrared absorbing material, and the printed object is irradiated with infrared light to read the characters and the like printed with the near-infrared absorbing material.

[0003] One such technique has been proposed, for example, in which a visible two-dimensional code and a transparent two-dimensional code are printed so that they at least partially overlap (see, for example, Patent Document 1). More specifically, the information in the visible two-dimensional code can be decoded using a key for the transparent two-dimensional code, and the authenticity of the printed information on the visible two-dimensional code can be confirmed by using the key.

[0004] JP 2018-89840 A

[0005] In recent years, interest in security has grown, and there has been a demand in various fields for technologies that can incorporate invisible information (e.g., characters, codes) into media. For example, as a countermeasure against counterfeit products, there is a demand for technologies that can incorporate invisible information into media such as printed matter using so-called invisible ink (generally ink made with near-infrared absorbing materials), making counterfeiting impossible. In addition, there is a demand for enhanced traceability of products and parts so that manufacturers can respond appropriately when product defects occur in the market. However, when various information is added to the product itself, there are limitations on the amount of data and the space available for addition, and some data does not necessarily need to be displayed on the product itself. Taking these factors into consideration, a new technology that can achieve both security and traceability is needed.

[0006] The present invention has been made in view of the above circumstances, and aims to provide a technology that achieves both security and traceability when code information is printed on a medium or the like.

[0007] The present invention provides the following technologies: (1) A code information printing system that prints code information in each process in a code area provided on a substrate where code information can be printed, the code information printing system comprising: code information generating means that generates new code information to be printed in an unprinted area of ​​the code area where no code information has been printed; data storage means that stores data included in the code information; printing means that prints the code information on the substrate; and data reference means that reads the printed code information, wherein at least a portion of the code information is printed using invisible ink containing a near-infrared absorbing material. (2) The code information printing system described in (1), wherein the data storage means stores information about the invisible ink used for printing in association with the data. (3) The code information printing system described in (2), wherein the data reference means selects a sensor to be used when reading the code information based on the information about the invisible ink. (4) The code information printing system according to any one of (1) to (3), wherein a plurality of pieces of code information can be printed in the code area, wherein the code information is printed for each process, and at least one of the plurality of pieces of code information is printed using the invisible ink. (5) The code information printing system according to any one of (1) to (4), wherein the code information generating means generates partial code information that is a part of the code information for each process, and the printing means prints the partial code information, and correct code information is obtained by combining the partial code information printed in all processes. (6) The code information generating means generates the code information by dividing it into partial code information (B) printed with the invisible ink and partial code information (A) printed with visible ink made of a material whose printed portion is visually recognizable under visible light and has no absorption in the near-infrared region, and the printing means prints the partial code information (B) with the invisible ink and the partial code information (A) with the visible ink.(7) The code information printing system according to any one of (1) to (6), wherein the printing means controls the amount of invisible ink to achieve a set optical density, and the data storage means stores information on the optical density in association with the data. (8) The code information printing system according to (7), wherein the data reference means adjusts the sensitivity of a sensor used to read the code information based on the information on the optical density. (9) The code information printing system according to any one of (1) to (8), wherein all of the code information has an area printed with the invisible ink. (10) The code information printing system according to any one of (1) to (9), further comprising a determination means, when printing new code information, for determining whether code information that should have been printed has been printed before printing the new code information, and for not allowing printing of the new code information if it has not been printed. (11) The code information printing system according to any one of (1) to (10), wherein the near-infrared absorbing material is a naphthalocyanine compound. (12) A medium on which code information is printed on a substrate using the code information printing system according to any one of (1) to (11). (13) A print control device that controls printing on a code area provided on a substrate where code information can be printed, the code area being divided into a plurality of partial areas, a printing device being provided for each of the plurality of partial areas, the print control device having: code information generation means for generating new code information to be printed in each of the plurality of partial areas; and print control means for causing the printing device corresponding to each of the plurality of partial areas to print the code information.(14) A print control device that uses a printer to print code information in a code area provided on a base and capable of printing the code information, the code area being divided into a plurality of partial areas, the partial areas corresponding to the printers being determined, the print control device comprising: code information generating means for generating new code information to be printed in the partial areas, storage processing means for storing data included in the code information in data storage means, and print control means for causing the printer to print the code information in the partial areas corresponding to the printer. (15) The print control device according to (13) or (14), wherein at least a portion of the code information is printed using invisible ink containing a near-infrared absorbing material.

[0008] According to the present invention, it is possible to provide a technology that achieves both security and traceability when printing code information on a medium or the like.

[0009] FIG. 1 is a block diagram showing a schematic configuration of a label management system according to an embodiment. FIG. 2 is a diagram illustrating steps of sequentially adding code information to a label using invisible ink in first to fourth steps according to an embodiment. FIG. 3 is a diagram showing alternative form 1 of code information printed in a code area according to an embodiment. FIG. 4 is a diagram showing alternative form 2 of code information printed in a code area according to an embodiment. FIG. 5 is a diagram showing alternative form 3 of code information printed in a code area according to an embodiment. FIG. 6 is a block diagram showing a schematic configuration of a central management device according to an embodiment. FIG. 7 is a block diagram showing a label management device according to an embodiment. FIG. 8 is a flowchart showing a code information printing process by a label management system according to an embodiment. FIG. 9 is a flowchart showing a code information reading process by a label data reference device according to an embodiment. FIG. 10 is a table showing an example of data stored in a management data storage unit according to an embodiment. FIG. 11 is a block diagram showing a computer according to an embodiment. FIG. 12 is a block diagram showing a printing device according to an embodiment.

[0010] In this specification, "invisible ink" refers to ink containing a near-infrared absorbing material, in which the printed portion using the ink is not visible or difficult to see under a typical visible light environment, but appears visible when irradiated with infrared light (including near-infrared light). Ink whose printed portion is visible under a typical visible light environment and made of a material that does not absorb in the near-infrared region is referred to as "visible ink," and ink whose printed portion is visible under a typical visible light environment and made of a material that absorbs in the near-infrared region is referred to as "normal ink." Furthermore, sensors that sense visible ink and normal ink are referred to as "visible sensors" or "normal sensors." The invention of this patent application may suitably utilize the invention disclosed in PCT / JP2021 / 43159 (filed November 25, 2021) filed by the applicant of the present application.

[0011] First, an embodiment that achieves both security and traceability using a code information printing system will be described. FIG. 1 is a block diagram showing the schematic configuration of a label management system 100 according to this embodiment. The label management system 100 is incorporated into a distribution system, a manufacturing system, etc., and prints predetermined data as code information 9, such as a QR Code (registered trademark), in invisible ink on management labels 1 associated with each managed item, such as a product or part, for each process (four processes in this case). Note that each process may not be located within the same factory or the same manufacturing company, but may be located across different factories or different manufacturing companies. The code information 9 may be printed directly on the label 1, or by attaching an adhesive label strip with the code information 9 printed on it to a predetermined area on the label 1. The code information 9 may also be printed on the product itself. Data that should be kept secret from a security perspective or data that does not need to be made visible during the manufacturing process is printed with invisible ink, while data that is to be displayed in a visible state is printed with normal ink or a visible sink.

[0012] Next, an embodiment will be described in detail, focusing on the fact that the code information 9 is printed using invisible ink. In this embodiment, the use of invisible ink further improves security. The label management system 100 has a central management unit 10, a label management device 20, a printing device 80, and a label data reference device 50.

[0013] The label management apparatus 20 includes a first label management apparatus 20A used in the first step, a second label management apparatus 20B used in the second step, a third label management apparatus 20C used in the third step, and fourth label management apparatuses 20A to 20D used in the fourth step. Hereinafter, when there is no need to distinguish between the first to fourth label management apparatuses 20D, they will be simply referred to as "label management apparatuses 20." The "label management apparatus 20" will be described in detail below with reference to FIG. 7.

[0014] The printing devices 80 include a first printing device 80A controlled by the first label management device 20A, a second printing device 80B controlled by the second label management device 20B, a third printing device 80C controlled by the third label management device 20C, and a fourth printing device 80D controlled by the fourth label management device 20D. That is, the first printing device 80A is used for printing in the first process, the second printing device 80B for the second process, the third printing device 80C for the third process, and the fourth printing device 80D for the fourth process. Hereinafter, when there is no need to distinguish between the first to fourth printing devices 80A to 80D, they will be simply referred to as "printing devices 80." The "printing devices 80" will be described in detail below with reference to FIG. 12 .

[0015] Note that in each process, the label management apparatus 20 and the printing apparatus 80 may be configured as an integrated unit. For example, the first label management apparatus 20A and the first printing apparatus 80A may be configured as a single apparatus. Also, the label management apparatus 20 and the printing apparatus 80 may be configured as an integrated unit in one process, and the label management apparatus 20 and the printing apparatus 80 may be configured as separate units in another process.

[0016] 11 is a diagram illustrating an example of a computer 1000 for realizing the label management system 100. The computer 1000 may be any of a variety of computers. For example, the computer 1000 may be a personal computer (PC), a server machine, a tablet terminal, a smartphone, or a terminal device. The computer 1000 may be a dedicated computer designed to realize the label management system 100, or may be a general-purpose computer. The computer 1000 is also a computer that realizes the central management device 10, label management device 20, printing device 80, and label data reference device 50 that make up the label management system 100.

[0017] The computer 1000 includes a bus 1010, a processor 1020, a memory 1030, a storage device 1040, an input / output interface 1050, and a network interface 1060. The bus 1010 is a data transmission path through which the processor 1020, the memory 1030, the storage device 1040, the input / output interface 1050, and the network interface 1060 transmit and receive data to and from each other. The processor 1020 is an arithmetic processing device such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). The memory 1030 is a main storage device formed of RAM (Random Access Memory) or the like. The storage device 1040 is an auxiliary storage device formed of a hard disk, an SSD (Solid State Drive), a memory card, a ROM (Read Only Memory), or the like. However, the storage device 1040 may also be formed using RAM or the like. The input / output interface 1050 is an interface for connecting the computer 1000 to input / output devices. For example, input devices such as a keyboard and a mouse, and output devices such as a display device are connected to the input / output interface 1050. The network interface 1060 is an interface for connecting to a communication network such as a WAN (Wide Area Network) or LAN (Local Area Network). The storage device 1040 stores program modules that realize each function of the label management system 100 (the central management unit 10, the label management device 20, the printing device 80, and the label data reference device 50). The processor 1020 reads each of these program modules into the memory 1030 and executes them to realize each function corresponding to the program module.

[0018] <Example of Implementation of Label Management System 100> Various types of computers can be used as the specific computer 1000 for implementing the label management system 100.

[0019] Specifically, for example, the computer 1000 is a server that functions as the central management unit 10, and is communicably connected to the label management unit 20, the printing device 80, and the label data reference device 50. The administrator of the central management unit 10 installs and runs an application that realizes the central management unit 10 on an external server. This enables the central management unit 10 to manage the label management unit 20, the printing device 80, and the label data reference device 50.

[0020] Furthermore, for example, the computer 1000 is a server that functions as the label management apparatus 20, and is communicably connected to the central management apparatus 10, the printing apparatus 80, and the label data reference apparatus 50. In this case, the administrator of the label management apparatus 20 installs and runs an application that realizes the functions of the label management apparatus 20 on the server. This causes the server to function as the label management apparatus 20. As a result, the user can use the label management apparatus 20 to perform label management, which will be described later.

[0021] Alternatively, for example, the computer 1000 is a terminal device that functions as the label data reference device 50, and is communicably connected to the central management device 10, the label management device 20, and the printing device 80. In this case, the user of the label data reference device 50 installs and runs an application that realizes the functions of the label data reference device 50 on the terminal device. This causes the terminal device to function as the label data reference device 50. As a result, the user can use the label data reference device 50 to perform the label data reference process, which will be described later.

[0022] The label management device 20, the printing device 80, and the label data referring device 50 may each be realized by a plurality of computers, or devices realizing different functions may be realized by a common computer.

[0023] Furthermore, for example, the computer 1000 is a device that functions as the printing device 80 and is communicably connected to the label management device 20. In this case, the administrator of the printing device 80 installs and runs an application that realizes the functions of the printing device 80 on the server. This causes the server to function as the printing device 80. As a result, the user can use the printing device 80 to perform the label printing process described below.

[0024] There are no particular restrictions on the type of data contained in the printed code information 9, but from the perspective of process management or traceability, examples of such data include information regarding materials, parts, work content, workers, work dates and times, etc.

[0025] <Form of Code Information 9> Next, the form of the code information 9 printed in the code area 2 will be described. In this embodiment, at least a portion of the code information 9 is printed using invisible ink in each process. "At least a portion of the code information 9" refers to one or more of the multiple code information 9, or at least one or more portions of a single code information 9, or a combination thereof. Figure 2 is a diagram illustrating four processes for sequentially adding code information 9 to the label 1 using invisible ink. Note that the upper row shows the state of the label 1 viewed visually under visible light. Since the code information 9 is not visible, it is shown here with dashed lines for convenience. The lower row shows the code information 9 read by an IR sensor after irradiating it with infrared light, and is shown with solid lines for convenience. Note that, for convenience, the example shown in Figure 2 will be referred to as Printing Form 1, and the examples described in Figures 3 to 5 below will be described as Printing Forms 2 to 4.

[0026] Although a product label (label 1) having adhesive on one side is exemplified as a substrate on which the code information 9 is printed with invisible ink, various other substrates can be used. The substrate may be, for example, a plate-like member such as paper, glass, film, or resin, as long as it has a flat surface on at least one side on which the code information 9 can be printed.

[0027] There are no particular restrictions on the technology (printing means) for printing the code information 9 on the substrate, as long as it is an on-demand printing technology. For example, plate-based printing includes letterpress printing (relief printing), offset printing (lithographic printing), gravure printing (intaglio printing), and screen printing (stencil printing). Plateless on-demand printing methods include, for example, laser printing, inkjet printing, and thermal transfer printing, and a printing device 80 that is easily available on the market can be selected depending on the type of medium to be printed and the conditions at the site where the printing will actually be performed.

[0028] The label 1 has a code area 2 in which code information 9 is printed. The code area 2 is divided into multiple partial areas. Here, four areas, first to fourth areas 2A to 2D, are provided, divided vertically and horizontally 2x2. First to fourth printing devices 80A to 80D are provided for each of the multiple partial areas, i.e., for each of the first to fourth areas 2A to 2D. The first to fourth printing devices 80A to 80D are controlled by the corresponding first to fourth label management devices 20A to 20D. When both code information 9 printed in invisible ink and information printed in normal ink (not shown) are printed, they may be printed overlapping each other. In this case, the label data reference device 50 (code reader) can selectively read either the overlapping information by irradiating visible light or infrared light.

[0029] After the first step is completed, the first printing device 80A prints the first code information 9A in the first area 2A (the upper left area of ​​the code area 2) of the label 1 in invisible ink, and information that should be visible (for example, information indicating that the first step has been performed) is printed in visible ink or regular ink. The label 1 is sent to the second step together with the product. At this time, the code information printed in the first step (i.e., the information superimposed on the first code information 9A) is tracked and recorded in the central management unit 10 (specifically, the management data storage unit 14 in FIG. 6 ).

[0030] Next, if the first area 2A contains information indicating that the first area has been completed at the start of the second process, after the second process is completed, the second printing device 80B prints second code information 9B in the second area 2B (the upper right area of ​​the code area 2) in invisible ink, while information that should be visible (e.g., information indicating that the second area has been completed) is printed in visible ink or regular ink. The label 1 is sent to the third process together with the product. At this time, the code information printed in the second process is tracked and recorded in the central management device 10 (specifically, the management data storage unit 14 in FIG. 6 ) in association with the code information from the previous first process.

[0031] In the third and fourth steps, similarly to the second step, once the previous steps (the second and third steps) are completed and the label 1 and product are sent to the current step (the third and fourth steps), if there is information indicating that the previous steps have been completed, the third and fourth printing devices 80C and 80D print code information 9 (third code information 9C and fourth code information 9D) in invisible ink in the code areas 2 corresponding to the third and fourth steps (i.e., the third area 2C and the fourth area 2D), respectively, after the third and fourth steps are completed. Information that should be visible is printed in visible or regular ink. The label 1 is then sent to the next step together with the product. The printed code information is tracked and recorded in the central management unit 10 (specifically, the management data storage unit 14 in FIG. 6 ) in association with the code information up to the previous step.

[0032] FIG. 3 illustrates another example (printing example 2) of the code information 9 printed in the code area 2. Here, the code area 2 is divided into two partial areas, an upper area and an lower area. The illustrated code information 9 is divided into partial code information (A) 9X printed in visible ink on the upper side and partial code information (B) 9Y printed in invisible ink on the lower side. When read with a visible sensor (normal sensor), the upper partial code information (A) 9X is recognized, and when read with an infrared sensor, the lower partial code information (B) 9Y is recognized. The upper and lower partial code information (A) 9X and partial code information (B) 9Y are combined to recognize the entire code information 9.

[0033] FIG. 4 illustrates another example (printing example 3) of the code information 9 printed in the code area 2. Here, the code area 2 is divided into four partial areas (first to fourth areas 2A to 2D). The illustrated code information 9 shows a form in which partial code information 9X1 to 9X4, which are parts of the code information 9, are generated for each process and printed in the first to fourth areas 2A to 2D. The correct code information 9 as a whole is recognized by combining the partial code information 9X1 to 9X4 printed in all processes (first to fourth processes in this case).

[0034] Figure 5 illustrates another embodiment 3 (printing embodiment 4) of the code information 9 printed in the code area 2. This shows a form in which code information is printed that includes areas with different optical densities (OD values) by changing the thickness of some of the printing layers (ink thickness) when printing the code information 9 in the code area 2. Here, the OD value will be explained. The OD value is a logarithmic representation of the degree of light absorption, and is expressed by the following formula (1). Here, (λ) is the wavelength, T(λ) is the amount of transmitted light in the wavelength band, and I(λ) is the amount of incident light in the wavelength band. From the above formula (1), it can be said that a smaller OD value indicates greater light transmission, and conversely, a larger OD value indicates less light transmission. In other words, the larger the OD value, the greater the absorption of infrared light, meaning that when read by the label data reference device 50, the label is clearly recognized as black.

[0035] The code information 9 shown on the left side of FIG. 5 represents a combination of a cell 91 (shown in black) with a high OD value and a cell 92 (shown in light black) with a low OD value. When printing each code information 9, the ink volume (thickness of the printing layer) can be adjusted to print cells with different OD values. When reading the data information with the label data reference device 50 (described later), the sensor threshold can be changed to recognize the cell 92 as "white" or "black." For example, if the cell 92 is recognized as "white," the code information 9 (display A) shown in the upper right of FIG. 5 is generated, and if it is recognized as "black," the code information 9 (display B) shown in the lower right of FIG. 5 is generated. Therefore, by presetting the sensor threshold when reading with the label data reference device 50, the correct code information 9 can be recognized. However, if the sensor threshold is inappropriate and the incorrect code information 9 is recognized, it can be determined that an inappropriate product, a counterfeit product, or inappropriate access has occurred. In the above explanation, we have described a case where the optical density (OD value) of some of the cells that make up the code information 9 is different, but of course, the code information 9 may also be printed so that the optical density (OD value) of all the cells that make up the code information 9 is low.

[0036] The code information 9 may also be printed using a plurality of invisible inks with different infrared absorption wavelength bands. For example, in FIG. 5 , cell 91 is printed by overlapping "invisible ink A," which allows information to be read using a light source having a dominant wavelength of 780 nm, and "invisible ink B," which allows information to be read using a light source having a dominant wavelength of 850 nm. On the other hand, cell 92 is printed only with "invisible ink A." As a result, when the information is read using a light source having a dominant wavelength of 780 nm, cells 91 and 92 are recognized as "black," as shown in display B. On the other hand, when the information is read using a light source having a dominant wavelength of 850 nm, cell 92 is recognized as "white," as shown in display A.

[0037] Information on which form of code information 9 shown in Figures 2 to 5 was used is stored in the management data storage unit 14 of the central management unit 10 at the time of printing, and the information on which form is used is referenced when sensing the code information 9.

[0038] <Central management unit 10> Fig. 6 is a block diagram showing a schematic configuration of the central management unit 10. The central management unit 10 functions as a central server that controls the entire label management system 100, and is connected to and controls the label management devices 20 and printing devices 80 in each process. The functions of the central management unit 10 may be configured to be included in the label management device 20. The central management unit 10 has a main control unit 11, a communication unit 12, a process management unit 13, and a management data storage unit 14. The main control unit 11 comprehensively controls each component of the central management unit 10. The communication unit 12 is an interface that communicates with external devices such as the label management device 20 and the label data reference device 50.

[0039] The process management unit 13 manages the label management devices 20 (first to fourth label management devices 20A to 20D) and the label data reference device 50 via the communication unit 12. The management data storage unit 14 stores the code information 9 imparted by printing to the code area 2 in each process and other information in association with each label 1. The management data storage unit 14 also stores, as necessary, information on the ink used for printing and the type of code information 9 (for example, the examples shown in Figures 2 to 5). The ink information includes the type of ink used, more specifically, whether it is invisible ink, visible ink, or normal ink, and, if it is invisible ink, information on the infrared absorption wavelength band, optical density, etc.

[0040] FIG. 10 shows an example of data stored in the management data storage unit 14. For each label number, the "date and time," "operator ID," "part lot number (part number)," "ink information," and "printing mode" for each process are recorded. For example, the information for the first process for label number "XXXX1" is as follows: date and time "2022 / 01 / 23 12:34," operator ID "000-01," part number "A1234," ink information "850 nm," and printing mode "1." Here, the ink information "850 nm" indicates that an invisible ink with an infrared absorption wavelength band of 850 nm was used. Note that if multiple invisible inks with the same infrared absorption wavelength band are used, the ink information is recorded to indicate which type of invisible ink was used. The printing mode "1" indicates that the mode in which the code information 9 is printed is printing mode 1 shown in FIG. 2. If the print mode is "3", it indicates that it is print mode 3 shown in FIG.

[0041] Furthermore, when the label data reference device 50 executes code reading, the process control unit 13 extracts the requested information from the control data storage unit 14 and transmits it to the label data reference device 50 .

[0042] <Label management device 20> Fig. 7 is a block diagram showing a schematic configuration of the label management device 20. The label management device 20 has a main control unit 21, a communication unit 22, an optical sensor 25, a print control unit 26, and a print data management unit 27. The main control unit 21 comprehensively controls the components of the label management device 20. The communication unit 22 is an interface that communicates with external devices such as the central management device 10 and the printing device 80.

[0043] The optical sensor 25 is an imaging means, and includes a visible light sensor 23 and an IR sensor 24. If it is not necessary to recognize the label 1 with the visible light sensor 23, the visible light sensor 23 is not necessary.

[0044] The visible light sensor 23 is a camera equipped with an imaging element that responds to visible light and captures color images using visible light. The visible light sensor 23 is used to determine the position of the label 1 and to acquire information printed in regular ink (or visible ink) contained on the label 1.

[0045] The IR sensor 24 includes an infrared irradiator that irradiates infrared light (including near-infrared light) and an infrared camera equipped with an image sensor that reacts to infrared light. The IR sensor 24 irradiates the label 1 (particularly the code area 2) with infrared light and reads the code information 9 printed in invisible ink in the code area 2. In other words, the IR sensor 24 functions as a code reader (similar in function to the label data reference device 50) that reads the code information 9.

[0046] While there are no particular limitations on the infrared light to be emitted, when considering the use of a semiconductor laser, the wavelength (center wavelength) of the infrared light is assumed to be, for example, 780 nm, 830 nm, 850 nm, 940 nm, 1300 nm, etc., taking into account implementation costs and marketability. In other words, semiconductor lasers that output the above wavelengths (780 nm, 830 nm, 850 nm, 940 nm, 1300 nm) are widely used as semiconductor lasers equipped in the reading device 90, and are therefore suitable from the standpoints of cost and technical stability. The wavelength of the infrared light selected depends on the near-infrared absorbing material used in the invisible ink. Note that when multiple types of invisible ink are used to print the code information 9, i.e., when multiple invisible inks with different infrared absorption wavelength bands are used, the IR sensor 24 is configured to selectively output and sense multiple types of infrared light. Invisible ink will be described later.

[0047] The color of the label 1 with only the code information 9 printed on it (i.e., the background color of the substrate of the label 1) is, for example, white. In other words, because the code information 9 is formed from an invisible near-infrared absorbing layer, the original background color of the label 1 is recognized as the color of the label 1 even when the code information 9 is printed in invisible ink.

[0048] The irradiated infrared light is absorbed in the areas of the near-infrared absorbing layer of the code information 9 where near-infrared absorbing material (which has the same wavelength as the irradiated infrared light as its absorption band) is provided, and is reflected in areas where no near-infrared absorbing material is provided, returning as reflected light to the IR sensor 24 or label data reference device 50 such as a code reader. As a result, the code information 9 appears to emerge and is recognized by the IR sensor 24 or label data reference device 50.

[0049] The light level irradiated onto the near-infrared absorbing material portion is recognized as "Low," and the light level irradiated onto other areas is recognized as "High," and the recognition result (black / white obtained by binarizing High / Low) is displayed on the display unit as code information 9. In other words, an image expressed in "black" and "white" becomes code information 9.

[0050] The print data management unit 27 aggregates data to be printed in each process and prints it on the label 1 using the printing device 80. Specifically, the print data management unit 27 classifies and creates data to be printed as code information 9 in invisible ink (conveniently referred to as "confidential data") and data to be printed in normal ink (conveniently referred to as "normal data"). The procedure for converting the confidential data into code information 9 is based on specifications established for the type (standard) of code information 9 to be created. The print data management unit 27 functions as code information generation means that generates new code information 9 to be printed in each of multiple partial areas. As shown in Figures 2 to 4, the code area 2 is divided into multiple partial areas, and a printing device 80 is provided for each of the multiple partial areas. The print data management unit 27 generates code information 9 in the partial area associated with each process, to be printed by the printing device 80 corresponding to that process. The print data management unit 27 functions as storage processing means that stores the data included in the code information 9 in the management data storage unit 14. Although the data to be printed as code information 9 has been described as being aggregated by the print data management unit 27, this is not limited to this. For example, the process management unit 13 of the central management unit 10 may aggregate the data in the management data storage unit 14 and transmit the data to the print data management unit 27.

[0051] The printing control unit 26 controls the printing device 80 to print the normal data using visible ink or normal ink, and the confidential data using invisible ink to encode the data and print it as code information 9 in a predetermined position. In other words, the printing control unit 26 causes the printing device 80 to print the code information 9 in the partial area corresponding to the printing device 80. For example, in the first process, as described above, the first label management device 20A controls the first printing device 80A to print the first code information 9A in the first area 2A. The printing control unit 26 also functions as a code information non-generation area detection unit that detects an area where no code information has been formed. That is, in each process, it determines whether or not there is an area where code information 9 should be printed. For example, in the second process, if other code information 9 has already been printed in the second area 2B of the label 1, the printing control unit 26 outputs an error. If detection of an area where no code information has been formed is unnecessary, the code information non-generation area detection unit may be omitted. In this case, the partial area to be printed is predetermined for each printing device 80, and the position is detected before printing.

[0052] <Printing device 80> The printing device 80 is a device that prints code information 9 in the code area 2 of the label 1 using invisible ink. The printing device 80 may also have the function of printing using regular ink or visible ink. Below, a configuration that includes regular ink and visible ink in addition to invisible ink will be described.

[0053] FIG. 12 is a functional block diagram of the printing device 80. The printing device 80 has a main control unit 81, a communication unit 82, a printing unit 83, a print control unit 84, and an ink unit 85. The main control unit 81 controls the components of the printing device 80. The communication unit 82 is an interface that communicates with external devices such as the central management unit 10, the label management device 20, and the printing device 80. The printing device 80 is connected to the label management device 20 via the communication unit 82. The printing unit 83 has a print head that ejects ink and a transport unit that transports the label 1 to a predetermined printing position. The print control unit 84 obtains data to be printed as code information 9 (image data of the code information 9, the type of ink to use, ink density, print position, etc.) from the label management device 20, and controls the printing unit 83 and the ink unit 85 to print the code information 9. The ink section 85 has an invisible ink section 86, a visible ink section 87, and a normal ink section 88, and supplies the ink necessary for printing to the printing section 83. The invisible ink section 86 contains invisible ink and supplies it to the printing section 83. The visible ink section 87 contains visible ink and supplies it to the printing section 83. The normal ink section 88 contains normal ink and supplies it to the printing section 83.

[0054] <Label Data Referencing Device 50> The label data referencing device 50 is a code reader that reads the code information 9 and has the functions of capturing color images using visible light with an imaging element that responds to visible light, and emitting infrared light and functioning as an infrared camera with an imaging element that responds to infrared light. It may be a portable type, a type that is fixed to a device, or, rather than a dedicated device, a general-purpose mobile terminal (such as a tablet or smartphone) equipped with an IR reading function. If decoding of the code information 9 is not required, the label data referencing device 50 converts the output of the imaging element into a predetermined data format for communication and transmits it to the central management unit 10. If decoding of the code information 9 is required, the label data referencing device 50 performs a predetermined decoding process, converts the processing result into a predetermined data format for communication, and transmits it to the central management unit 10.

[0055] <Invisible Ink Materials> The printing materials used in invisible ink are selected depending on the type of printing. The printing materials contain pigments, coloring matter, and binder resins, and may further contain other components as necessary, and any of the materials listed below may be used. For convenience, printing materials composed of pigments and coloring matter that have infrared absorbing properties are referred to as "near-infrared absorbing materials" herein.

[0056] The binder resin is not particularly limited, and any conventionally known binder resin can be used. Examples include styrene-based resins such as styrene, α-methylstyrene, chlorostyrene, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, and styrene-acrylonitrile-acrylic acid ester copolymer; polyester resins; vinyl chloride resins; rosin-modified maleic acid resins; phenolic resins; epoxy resins; polyethylene resins; polypropylene resins; ionomer resins; polyurethane resins; silicone resins; ketone resins; xylene resins; petroleum-based resins; and hydrogenated petroleum-based resins. These may be used alone or in combination of two or more. Among these, styrene-based resins and polyester resins containing an aromatic compound as a structural unit are preferred, with polyester resins being more preferred.

[0057] The polyester resin can be obtained by a generally known polycondensation reaction between an alcohol and an acid. Examples of the alcohol include diols such as polyethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-propylene glycol, neopentyl glycol, and 1,4-butenediol; etherified bisphenols such as 1,4-bis(hydroxymethyl)cyclohexane, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, and polyoxypropylenated bisphenol A; and saturated or unsaturated bisphenols having 3 to 22 carbon atoms. Examples of such monomers include dihydric alcohol units substituted with hydrocarbon groups, other dihydric alcohol units, and trihydric or higher alcohol monomers such as sorbitol, 1,2,3,6-hexanetetrol, 1,4-salbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene. These may be used alone or in combination of two or more.

[0058] The acid is not particularly limited and can be appropriately selected depending on the purpose, but carboxylic acids are preferred. Examples of carboxylic acids include monocarboxylic acids such as palmitic acid, stearic acid, and oleic acid, maleic acid, fumaric acid, mesaconic acid, citraconic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, and malonic acid, divalent organic acid monomers obtained by substituting these with saturated or unsaturated hydrocarbon groups having 3 to 22 carbon atoms, anhydrides of these acids, dimers of lower alkyl esters and linoleic acid, 1,2,4-benzenetricarboxylic acid, and 1, Examples of such monomers include trivalent or higher polyvalent carboxylic acid monomers such as 2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, tetra(methylenecarboxyl)methane, 1,2,7,8-octanetetracarboxylic acid, Embol trimer acid, and anhydrides of these acids. These may be used alone or in combination of two or more.

[0059] The binder resin may also contain a crystalline resin. The crystalline resin is not particularly limited as long as it has crystallinity and can be appropriately selected depending on the purpose. Examples include polyester resins, polyurethane resins, polyurea resins, polyamide resins, polyether resins, vinyl resins, and modified crystalline resins. These may be used alone or in combination of two or more. Among these, polyester resins, polyurethane resins, polyurea resins, polyamide resins, and polyether resins are preferred, and resins having at least one of a urethane skeleton and a urea skeleton are preferred in order to provide moisture resistance and incompatibility with the amorphous resin described below.

[0060] The near-infrared absorbing material is not particularly limited and may be either an organic material or an inorganic material, but from the viewpoint of being used as a printing ink medium, an organic material is preferred.

[0061] Examples of organic materials that can be used include cyanine compounds, phthalocyanine compounds, naphthalocyanine compounds, anthraquinone compounds, dithiol metal complexes, aminium compounds, immonium compounds, azo compounds, squarylium compounds, etc. In this specification, for example, the term "naphthalocyanine compounds" refers to a general term for metal naphthalocyanine compounds having a substituent, metal-free naphthalocyanine compounds having a substituent, metal naphthalocyanine compounds having no substituent, and metal-free naphthalocyanine compounds having no substituent.

[0062] These compounds exhibit excellent absorption of near-infrared light. Specifically, they have maximum absorption characteristics (maximum absorption wavelength) in the range of 700 nm to 1400 nm in their absorption distribution. More specifically, they are materials that satisfy the physical properties described above and can effectively absorb near-infrared light output from a semiconductor laser at wavelengths such as 780 nm, 830 nm, 850 nm, and 1300 nm, but have low absorption characteristics in the visible light region (e.g., 400 nm to 750 nm). Therefore, when a medium is printed with a near-infrared absorbing material composed of these compounds, the printed portion is not visible.

[0063] In particular, phthalocyanine compounds and naphthalocyanine compounds are suitable because they have more favorable near-infrared absorption performance and require ease of adjustment when adjusting the optical density (OD) value by the thickness of the invisible ink (i.e., near-infrared absorbing material). Among phthalocyanine compounds and naphthalocyanine compounds, pigment compounds have favorable performance in terms of weather resistance (durability). That is, a medium (here, label 1) on which code information 9 containing a near-infrared absorbing material is printed can maintain its functionality. Furthermore, when considering the durability of dye images, naphthalocyanine compounds are preferred. This is because the π-conjugated system is expanded compared to phthalocyanine compounds, resulting in a so-called rigid structure and excellent weather resistance. Shifting the absorption band of phthalocyanine compounds and naphthalocyanine compounds to the desired near-infrared region requires adjustments such as introducing a substituent or changing the metal. Preferably, vanadyl naphthalocyanine compounds which may have as a substituent one or more of a nitro group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted alkylamino group, and copper naphthalocyanine compounds which may have as a substituent one or more of a nitro group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted alkylamino group, are more preferred, and more specifically, vanadyl naphthalocyanine compounds which may have as a substituent one or more of a nitro group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted alkylamino group are particularly preferred.

[0064] Organic near-infrared absorbing materials lose their performance when exposed to the atmosphere, ultraviolet rays, etc., but if the rate of degradation is slow, they can function as printing materials without any special measures to prevent degradation. When preparing printing materials, the near-infrared absorbing material may be finely divided and dispersed to an average particle size of 0.5 microns or less, preferably 0.3 microns or less, more preferably 0.2 microns or less, and particularly preferably 0.1 microns or less, taking into consideration the solubility of the material in organic solvents, etc. In this case, the smaller the particle size, the better the dispersibility, resulting in an excellent invisible ink with excellent transparency after printing and little coloration in the visible range. The method for finely pulverizing the near-infrared absorbing material is not particularly limited, and may be either dry or wet, with methods such as sand milling, ball milling, and spike milling being used. When mixing, additives that aid in fine particle size reduction and stabilization may be added as necessary.

[0065] The range of the amount of the near-infrared absorbing material varies depending on the properties of the near-infrared absorbing material. However, regardless of the type of near-infrared absorbing material, if the amount is insufficient, the absorption of infrared light will be insufficient.

[0066] The other components are not particularly limited as long as they are normally contained in printing inks (including toners), and can be appropriately selected depending on the purpose. Examples include a release agent, a charge control agent, and an external additive.

[0067] <Processing of the Label Management System 100> <Printing Process of Code Information 9> First, the printing process of code information 9 by the label management system 100 will be described. Here, an example of the processing of the second step in FIG. 1 will be described. Note that FIG. 8 is a flowchart showing the printing process of code information 9 by the label management system 100. The data to be included in the code information 9 is generated and aggregated by the label management device 20 corresponding to each step (for example, the second label management device 20B in the case of the second step) at the timing when each step is completed. At this time, the label management device 20 refers to the management data storage unit 14 of the central management device 10 as necessary. Furthermore, the central management device 10 may generate and aggregate various data to be included in the code information 9 instead of the label management device 20.

[0068] When a predetermined task or the like in a predetermined process (here, the second process) is completed and the printing control unit 26 in the label management apparatus 20 (here, the second label management apparatus 20B) acquires a label printing instruction (S11), the printing control unit 26 checks the printing area of ​​the code area 2 and confirms that nothing has been printed in the area (here, the second area 2B) where code information 9 should be printed in invisible ink in the process (here, the second process) (S12). If something has already been printed in the second area 2B, error processing is performed. If necessary, it may also be confirmed whether the invisible ink code information 9 or information using visible ink or normal ink has been properly printed in the area (here, the first area 2A) where printing should have been done in the previous process (here, the first process).

[0069] If nothing is printed in the second area 2B, the print data management unit 27 collects the data to be included in the code information 9 and the associated data to be stored in the management data storage unit 14, and generates the code information 9 (S13).

[0070] The print control unit 26 controls the second printing device 80B to print the generated code information 9 in the second area 2B of the label 1 in invisible ink (S14). The print data management unit 27 also sends the data included in the code information 9 and related data to the central management unit 10 (S15). In the central management unit 10, the data sent from the second label management device 20B is recorded in the management data storage unit 14 (S16). At this time, the data stored in the previous process (here, the first process) for the same label 1 is added to and updated.

[0071] <Reading Process of Code Information 9> Secondly, a description will be given of the code reader process of reading the code information 9 by the label data referring device 50. FIG.

[0072] When the label data referencing device 50 captures an image of the code area 2 on the label 1 (S21), it receives a designation from the user as to which of the first to fourth areas 2A to 2D of the code area 2 the code information 9 should be read from (S22). At this time, the designation may be one or all. Next, the label data referencing device 50 sets the sensor characteristic values ​​of the infrared sensor function that should be set when reading the code information 9 in the designated area (S23). If setting of the sensor characteristic values ​​is not necessary, this process is skipped.

[0073] For example, as shown in Figure 5, if the code information 9 is printed to have multiple optical densities (OD values) and the sensor settings (setting values ​​corresponding to the OD values) to be set in advance are known, then those values ​​are set. It is preferable that the absorption wavelength range of the near-infrared absorbing material and the wavelength range of the infrared sensor function match. Setting the wavelength range using the threshold value of sensor sensitivity can reduce misreading.

[0074] Furthermore, when the label data reference device 50 accesses the central management unit 10 and is authenticated, the sensor characteristic values ​​(OD values, etc.) stored in the management data storage unit 14 of the central management unit 10 are notified to the label data reference device 50. Furthermore, key information printed using normal ink may be used to access the correct data in the management data storage unit 14.

[0075] Once the sensor characteristic values ​​have been set as necessary, the label data reference device 50 reads the code information 9 in the specified area (S24), performs image processing using the sensor characteristic values ​​to obtain a binary black and white code information image, and accesses the information storage destination (the central management device 10 (management data storage unit 14)) obtained from the code information image to perform data inquiry processing (S25). At this time, as shown in printing mode 2 in FIG. 3, if the code information 9 is composed of visible ink and invisible ink, the image read by the normal visible sensor and the image read by the infrared sensor are combined and recognized as one correct code information 9. Also, as shown in printing mode 3 in FIG. 4, portions (partial code information) of the code information 9 are printed in each process (first to fourth regions 2A to 2D), and if the correct code information 9 is completed by combining the partial code information printed in all processes, all partial code information is combined and recognized as one code information 9.

[0076] In the central management unit 10, the process management section 13 determines whether the data inquiry from the label data reference device 50 is correct and extracts the data (S26). Methods for determining whether the data inquiry is correct include determining whether the code information 9 itself is correct or whether the code information 9 is printed in invisible ink in all code areas 2. If the data inquiry is correct, the process management section 13 extracts the correct data corresponding to the inquiry from the management data storage section 14 and transmits it to the label data reference device 50 (S27). The label data reference device 50 receives the data obtained from the central management unit 10 and displays it on its display screen (S28).

[0077] Although the embodiments of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various other configurations can also be adopted.

[0078] Summary of Features of the Present Embodiment The features of the present embodiment are summarized below. (1) A code information printing system (label management system 100) that prints code information 9 in a printable code area 2 provided on a substrate for each process (first to fourth processes in this case), includes: code information generation means (print data management unit 27) that generates new code information 9 to be printed in an unprinted area of ​​the code area 2 where no code information is printed; data storage means (management data storage unit 14) that stores data included in the code information 9; printing means (printing device 80) that prints the code information 9 on the substrate (i.e., the code area 2 of the label 1); and data reference means (label data reference device 50) that reads the printed code information 9, wherein at least a portion of the code information 9 is printed using invisible ink containing a near-infrared absorbing material. As a result, information that does not need to be communicated to the final customer (e.g., a market customer) is printed using invisible ink, which eliminates visual clutter and allows for simple packaging, etc. Furthermore, if a product has a problem in the market, product information can be tracked based on the code information 9 printed in invisible ink. Furthermore, checking for the presence or absence of the code information 9 printed in invisible ink can prevent the inclusion of counterfeit or counterfeit products during distribution. Furthermore, since the code information 9 is managed by the central management device 10, counterfeiting of the code information 9 can be prevented. Furthermore, each processing manufacturer can determine that a product in a previous process is not genuine if the invisible ink code information 9 is not present, thereby preventing the inclusion of counterfeit or counterfeit products. Furthermore, when recycling products printed with the code information 9, the recycled content of the main raw materials, the name of the recycled product manufacturer, etc., generally do not need to be communicated to customers in the market, but manufacturers and distributors can track and obtain such information as needed. (2) The data storage means (management data storage unit 14) stores information about the invisible ink used for printing in association with the data (i.e., data related to the code information 9). (3) The data reference means (label data reference device 50) selects the sensor to use when reading the code information 9 based on the invisible ink information.(4) Multiple pieces of code information 9 can be printed in the code area 2, and the code information 9 is printed for each process, with at least one of the multiple pieces of code information 9 being printed using the invisible ink. (5) The code information generation means (print data management unit 27) generates partial code information that is part of the code information 9 for each process and prints the partial code information using the printing means (printing device 80), and the correct code information is generated by combining the partial code information printed in all processes. (6) The code information generation means (print data management unit 27) generates the code information 9 by dividing it into partial code information (B) 9Y printed using invisible ink and partial code information (A) 9X printed using visible ink made of a material that can be visually recognized in a visible light environment and has no absorption in the near-infrared region, and the printing means (printing device 80) prints the partial code information (B) 9Y using invisible ink and the partial code information (A) 9X using the visible ink. (7) The printing means (printing device 80) controls the amount of invisible ink to achieve a set optical density (OD value), and the data storage means (management data storage unit 14) stores optical density information in association with the data. (8) The data reference means (label data reference device 50) adjusts the sensitivity of the sensor (infrared sensor) used to read the code information 9 based on the optical density information. (9) All of the multiple code information 9 have areas printed with invisible ink. (10) The system further includes a determination means (printing control unit 26) for determining whether code information that should be printed before printing new code information has been printed, and for not allowing printing of the new code information if it has not been printed. (11) The near-infrared absorbing material is a naphthalocyanine compound. (12) A medium (label 1) having code information printed on a substrate using any of the code information printing systems described above.(13) A print control device (label management device 20) that is provided on a base and controls printing on a code area 2 in which code information 9 can be printed, wherein the code area 2 is divided into a plurality of partial areas (see, for example, Figures 2 to 4), a printing device 80 is provided for each of the plurality of partial areas, and the print control device (label management device 20) has: code information generation means (print data management unit 27) that generates, for each of the plurality of partial areas, new code information 9 to be printed in that partial area; and print control means (print control unit 26) that causes, for each of the plurality of partial areas, the printing device 80 that corresponds to that partial area to print the code information 9. (14) A print control device (first to fourth label administration devices 20A to 20D) that uses a printer 80 to print code information 9 in a code area 2 provided on a base and capable of printing the code information 9, wherein the code area 2 is divided into a plurality of partial areas, the partial areas corresponding to the printers 80 are determined, the print control device (first to fourth label administration devices 20A to 20D) comprising: code information generation means (print data management unit 27) that generates new code information 9 to be printed in the partial area, storage processing means (print data management unit 27) that stores data included in the code information 9 in data storage means (management data storage unit 14), and print control means (print control unit 26) that causes the printer 80 to print the code information 9 in the partial area corresponding to the printer 80. (15) At least a part of the code information 9 is printed using invisible ink containing a near-infrared absorbing material.

[0079] This application claims priority based on Japanese Patent Application No. 2022-064336, filed April 8, 2022, the disclosure of which is incorporated herein in its entirety.

[0080] REFERENCE SIGNS LIST 1 Label 2 Code area 9 Code information 10 Central management unit 11, 21 Main control unit 12, 22 Communication unit 13 Process management unit 14 Management data storage unit 20 Label management device 20A to 20D First to fourth label management device 23 Visible sensor 24 IR sensor 25 Optical sensor 26 Printing control unit 27 Print data management unit 50 Label data reference device 80 Printing device 80A to 80D First to fourth printing device 91, 92 Cell 100 Label management system

Claims

1. A code information printing system that prints code information in a printable code area provided on a substrate, for each process, comprising: a code information generating means for generating new code information to be printed in an unprinted area of ​​the code area where no code information is printed; a data storage means for storing data included in the code information; a printing means for printing the code information on the substrate; data reference means for reading the printed code information; and A code information printing system, wherein at least a portion of the code information is printed using invisible ink containing a near-infrared absorbing material.

2. 2. The code information printing system according to claim 1, wherein said data storage means stores information about invisible ink used in printing in association with said data.

3. 3. The code information printing system according to claim 2, wherein said data reference means selects a sensor to be used when reading said code information based on information about said invisible ink.

4. A plurality of pieces of code information can be printed in the code area, The code information is printed for each process, The code information printing system according to claim 1 , wherein at least one of the plurality of pieces of code information is printed using the invisible ink.

5. the code information generating means generates partial code information that is a part of the code information for each process, and prints the partial code information using the printing means; 4. The code information printing system according to claim 1, wherein correct code information is obtained by combining the partial code information printed in all steps.

6. the code information generating means generates the code information by dividing it into partial code information (B) printed with the invisible ink and partial code information (A) printed with visible ink, the printed portion of which is visually recognizable under a visible light environment and made of a material that does not absorb in the near-infrared region; 4. The code information printing system according to claim 1, wherein the printing means prints the partial code information (B) in the invisible ink and prints the partial code information (A) in the visible ink.

7. the printing means controls the amount of the invisible ink so as to achieve a set optical density; 4. The code information printing system according to claim 1, wherein the data storage means stores the optical density information in association with the data.

8. 8. The code information printing system according to claim 7, wherein said data reference means adjusts the sensitivity of a sensor used when reading said code information based on said optical density information.

9. The code information printing system according to claim 1 , wherein all of the code information has an area printed using the invisible ink.

10. 4. The code information printing system according to claim 1, further comprising a determination means for determining whether or not code information that should be printed has been printed before printing new code information, and for not permitting printing of the new code information if the code information has not been printed.

11. 4. The code information printing system according to claim 1, wherein the near-infrared absorbing material is a naphthalocyanine compound.

12. A medium having code information printed on a substrate using the code information printing system according to any one of claims 1 to 3.

13. A print control device that controls printing on a code area provided on a substrate and in which code information can be printed, the coding region is divided into a plurality of subregions, a printing device is provided for each of the plurality of partial areas, a code information generating means for generating new code information to be printed in each of the plurality of partial areas; a print control unit that causes the printing device corresponding to each of the plurality of partial areas to print the code information; A print control device having the above configuration.

14. A print control device that uses a printing device to print code information in a code area that is provided on a base, the print area comprising: the coding region is divided into a plurality of subregions, The partial area corresponding to the printing device is determined, a code information generating means for generating new code information to be printed in the partial area; a print control means for causing the printing device to print the code information in the partial area corresponding to the printing device; A print control device having the above configuration.

15. 15. The print control device according to claim 13, wherein at least a part of the code information is printed using invisible ink containing a near-infrared absorbing material.