Information code, code generation method, and code reading method

Abstract

An information code (CQ2) is a combination of a secret code (Cd2) and a public code (Cd1) in which information is recorded by means of a two-dimensional array of a plurality of cells (Ce). The information code (CQ2) contains white cells (Cww) and black cells (Cbw) and also white dot cells (Cwc) and black dot cells (Cbc). In each white dot cell (Cwc), a white dot area enclosed by a black outer area is formed. In each black dot cell (Cbc), a black dot area enclosed by a white outer area is formed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2022-83973 filed in Japan on May 23, 2022, and the contents of the original application are incorporated by reference in their entirety. [Technical Field]

[0002] The disclosure of this specification relates to a technology for an information code for recording information. [Background technology]

[0003] Patent Document 1 describes an information code that combines two two-dimensional codes. This information code includes light gray cells and dark gray cells in addition to black and white cells. The two-dimensional arrangement of these four types of cells makes it possible to read the information of the two two-dimensional codes from the information code. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-196762 Summary of the Invention

[0005] In the information code of Patent Document 1, the shade of the gray cells, which are an intermediate color, is easily affected by the light that hits the information code. Therefore, for example, when a shadow is cast on only a part of the information code, it becomes difficult to distinguish between light gray cells and dark gray cells, which can easily lead to failure in reading the code.

[0006] The present disclosure aims to provide an information code that can reduce reading failures, as well as a method for generating and reading such an information code.

[0007] In order to achieve the above object, one disclosed embodiment is an information code formed by combining a first code and a second code that record information by a two-dimensional arrangement of multiple cells, and includes a light cell, a dark cell, a medium-light cell in which a medium-light region surrounded by an outer dark region is formed in the cell, and a medium-dark cell in which a medium-dark region surrounded by an outer light region is formed in the cell.

[0008] Another disclosed aspect is a code generation method in which a process performed by at least one processing unit includes the steps of preparing a first code and a second code that record information using a two-dimensional array of multiple cells, and generating an information code by combining the first code and the second code, and in the step of combining the first code and the second code, a cell where the first code and the second code are both light cells is set to a light cell, a cell where the first code and the second code are both dark cells is set to a dark cell, a cell where the first code is a light cell and the second code is a dark cell is set to a medium-light cell with a medium-light region surrounded by an outer dark region, and a cell where the first code is a dark cell and the second code is a light cell is set to a medium-dark cell with a medium-dark region surrounded by an outer light region.

[0009] Another disclosed aspect is a code reading method for reading a second code from an information code formed by combining a first code and a second code that record information using a two-dimensional array of multiple cells, the code reading method including, in processing performed by at least one processing unit, the steps of: designating, among the cells of the information code, medium-light cells having a medium-light area surrounded by an outer dark area as dark cells; and designating, among the cells of the information code, medium-dark cells having a medium-dark area surrounded by an outer light area as light cells.

[0010] In these embodiments, in addition to the light and dark cells, a medium-light cell having a medium-light region surrounded by an outer dark region and a medium-dark cell having a medium-dark region surrounded by an outer light region are used. Therefore, even if the information code is affected by light, it is unlikely that the medium-light cell and the medium-dark cell will be difficult to distinguish. As a result, it is possible to reduce failures in reading the code.

[0011] It should be noted that the reference numbers in parentheses in the claims merely indicate an example of the correspondence with specific configurations in the embodiments described below, and do not in any way limit the technical scope. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a diagram showing an information code according to the first embodiment of the present disclosure. [Figure 2] FIG. 1 is a diagram showing an overall view of a case where a traceability system is operated together with an existing distribution management system. [Figure 3] FIG. 10 is a diagram for explaining rules for combining a public code and a confidential code. [Figure 4] 10 is a flowchart showing details of a code generation process performed by a history management server. [Figure 5] 10 is a flowchart showing details of a code reading process performed by a code scanner or the like. [Figure 6] 10A and 10B are diagrams showing details of image processing for converting a white cell and a black cell into a black cell and a white cell. [Figure 7] FIG. 10 is a diagram showing a white cell and a black cell in Modification Example 1. [Figure 8] FIG. 10 is a diagram showing a white cell and a black cell in Modification Example 2. [Figure 9] FIG. 10 is a diagram showing a white cell and a black cell of Modification Example 3. [Figure 10] FIG. 10 is a diagram showing a white cell and a black cell in Modification 4. DETAILED DESCRIPTION OF THE INVENTION

[0013] The information code CQ2 according to an embodiment of the present disclosure shown in FIG. 1 is generated by a process of combining two two-dimensional codes. The two-dimensional code that is the basis of the information code CQ2 is, for example, a QR Code (registered trademark), and records information using a two-dimensional array of multiple cells Ce. The information code CQ2 is printed on a paper medium or the like and is used in the form of a code printing medium such as a label, sticker, or tag. The information code CQ2 may be displayed on a display device such as a display or electronic paper.

[0014] The information code CQ2 of this embodiment is generated by combining the public code Cd1 and the confidentiality code Cd2. When the information code CQ2 is read using a normal reader such as the code reader 13 (see FIG. 2) described later, the information code CQ2 is recognized as the public code Cd1. In this case, the information recorded in the public code Cd1 (hereinafter referred to as public information) is read. On the other hand, the confidentiality code Cd2 can be read by using a special reader such as the code scanner 23 (see FIG. 2) described later. In this case, the information recorded in the confidentiality code Cd2 (hereinafter referred to as confidential information) is read.

[0015] The information code CQ2 is used in both the distribution management system 110 and the traceability system 120 shown in FIG. 2. The distribution management system 110 and the traceability system 120 are management systems that manage a supply chain SC that is constructed including a large number of traders TR. The supply chain SC is a connection between traders for delivering industrial products, agricultural products, marine products, etc. to end users. As an example, in a supply chain SC for delivering agricultural products to consumers, the traders TR include a farmer TR1, an agricultural cooperative TR2 that serves as a collection facility, a transporter TR3, and a retailer TR4.

[0016] The distribution management system 110 collects transaction records of transaction items between traders TR using a public code Cd1. In other words, the public code Cd1 is a QR code operated by the distribution management system 110. The distribution management system 110 is composed of an input terminal 11, a label printer 12, a code reader 13, a system server 10, etc. The input terminal 11, label printer 12, and code reader 13 are appropriately installed in the facilities of each trader TR. The input terminal 11, label printer 12, and code reader 13 are connected via a network to the system server 10 installed in a data center or the like.

[0017] The input terminal 11 is, for example, a personal computer or a tablet terminal. Basic information (hereinafter referred to as item information) of a trade item supplied to the supply chain SC is input to the input terminal 11 in a predetermined format. For example, the item information may include the product name, place of production, production equipment, and manufacturer. The input terminal 11 transmits the item information of the trade item shipped from the trader TR to the system server 10.

[0018] The label printer 12 is an output device for printing the disclosure code Cd1 on a paper medium. The label printer 12 is a monochrome printer that can only perform monochrome printing. The paper medium on which the disclosure code Cd1 is printed is affixed to the package or outer box of the trade item to be shipped, and is distributed as an attachment to the trade item.

[0019] The code reader 13 is a reading device that reads the public code Cd1 to obtain the public information recorded in the public code Cd1. The code reader 13 obtains the public information recorded in the public code Cd1 and transmits the obtained public information to the system server 10.

[0020] The system server 10 is a host node capable of communicating with the input terminal 11, label printer 12, and code reader 13. The system server 10 registers item information acquired from the input terminal 11 in a database. The system server 10 prepares public information linked to the item information and generates a public code Cd1 that records this public information. As part of the process of issuing the public code Cd1, the system server 10 transmits image data, etc. of the generated public code Cd1 to the label printer 12, which is the sender of the item information. When the issued public code Cd1 is circulated together with a transaction item and is read by the code reader 13 of another transactor TR, the system server 10 accumulates a transaction record of the transaction item by this transactor TR.

[0021] The traceability system 120 is used in conjunction with the distribution management system 110, and accumulates transaction records in the same way as the distribution management system 110. Specifically, the distribution management system 110 corresponds to the old management system, and the traceability system 120 corresponds to the new management system. The traceability system 120 is operated together with the existing distribution management system 110 without making any substantial changes to the distribution management system 110. In addition to a record generation function that accumulates transaction records, the traceability system 120 also has a record reference function that makes the accumulated transaction records available for reference. The traceability system 120 uses blockchain technology to manage transaction records in order to prevent tampering with the transaction records.

[0022] The traceability system 120 collects transaction records using an information code CQ2 based on a public code Cd1 issued by the system server 10. The traceability system 120 is composed of a code output device 22, a code scanner 23, a history management server 20, etc. Furthermore, the traceability system 120 uses an input terminal 11 and a label printer 12, etc. of the distribution management system 110. The code output device 22, the code scanner 23, and the input terminal 11 are connected via a network to the history management server 20 installed in a data center or the like.

[0023] The code output device 22 is installed at the facility of the trader TR where the label printer 12 is installed. The code output device 22 is installed so as to interrupt the communication line between the system server 10 and the label printer 12, and acquires the data of the disclosure code Cd1 sent from the system server 10 to the label printer 12. The code output device 22 transmits the acquired data of the disclosure code Cd1 to the history management server 20.

[0024] The code output device 22 receives from the history management server 20 the data of the information code CQ2, which is generated based on the transmitted public code Cd1. The information code CQ2 further records confidential information used in the traceability system 120. The code output device 22 transmits the data of the information code CQ2 to the label printer 12, replacing the data of the public code Cd1. With the intervention of the code output device 22, the label printer 12 prints the information code CQ2 on a paper medium without recognizing that the acquired code data has been altered (replaced). As a result, a code printing medium with the printed information code CQ2 is affixed to a transaction item instead of the public code Cd1, and is distributed together with the transaction item.

[0025] The code scanner 23 is a reading device that reads the information recorded in the information code CQ2, i.e., the secret information added to the information code CQ2 separately from the public information. The code scanner 23 is configured to scan the same object as the code reader 13, and therefore may be physically integrated with the code reader 13. The code scanner 23 is composed of an image sensor formed by a two-dimensional array of CCD elements, a signal processing unit 41, etc. The image sensor is capable of reading information recorded in a plane with a higher resolution than the code reader 13. The image sensor outputs an image showing the information code CQ2 (hereinafter referred to as a code image) to the signal processing unit 41.

[0026] The signal processing unit 41 has a memory unit that stores a code reading program and the like, a processor that executes the code reading process (see FIG. 5) described below based on the code reading program, and RAM. The signal processing unit 41 decodes the read signal (code image) from the image sensor according to a predetermined rule through the code reading process, and acquires the confidential information recorded in the information code CQ2. Based on the acquired confidential information, the signal processing unit 41 communicates with the history management server 20 to leave a transaction record.

[0027] A smartphone, tablet terminal, or the like having a camera function may be used as the code scanner 23. In such a case, a dedicated application equivalent to a code reading program is provided and installed on the smartphone or the like.

[0028] The history management server 20 is a host node capable of communicating with the input terminal 11 in addition to the code output device 22 and the code scanner 23. The history management server 20 is mainly configured as a computer including a processing unit 31, RAM 32, a storage unit 33, an input / output interface, and a bus connecting these. The processing unit 31 is hardware for arithmetic processing coupled to the RAM 32. The processing unit 31 accesses the RAM 32 to execute various processes related to data management. The storage unit 33 stores a code generation program, as one of the management programs related to data management, for causing the processing unit 31 to execute the code generation method according to the present disclosure.

[0029] The history management server 20 acquires item information sent from the input terminal 11 to the system server 10. Based on the acquired item information, the history management server 20 generates a blockchain linked to the traded item, which stores the item information and transaction records. When the history management server 20 acquires a notification from the code scanner 23 of each trader TR that the information code CQ2 has been read, the history management server 20 accumulates the transaction record of the trader TR that sent the notification in the blockchain linked to the traded item.

[0030] Specifically, when the history management server 20 receives a notification from the code scanner 23, it generates a new block that stores the transaction records of the notifying transactor TR. The new block contains not only the current transaction record but also a hash value calculated from the previous block. A hash function such as SHA-256 is used to generate the hash value. The hash value is data that maintains a predetermined number of bits (e.g., 256 bits) and reflects item information and transaction records.

[0031] Based on the data of the public code Cd1 acquired from the code output device 22, the history management server 20 performs the code generation process (see FIG. 4) described below to generate an information code CQ2 that records at least the above-mentioned hash value as confidential information. The history management server 20 issues the generated information code CQ2 to the code output device 22. As a result, the hash value that reflects the item information and transaction record is recorded in the information code CQ2, which can be circulated together with the transaction item.

[0032] In the traceability system 120, a single information code CQ2 may be continuously used across multiple traders TR, or a new information code CQ2 may be issued for each trader TR. In a case where a new information code CQ2 is issued for each trader TR, a new hash value reflecting the transaction record is generated based on the occurrence of a transaction record at each trader TR. The history management server 20 generates a new information code CQ2 that records the new hash value as confidential information and provides the data of the new information code CQ2 to the label printer 12 installed at the facility of the trader TR that conducted the transaction. As a result, as the transaction of an item progresses, the content (hash value) of the information code CQ2 is continually updated to reflect the transaction record up to that point. Furthermore, because the confidential information is primarily based on the hash value, the amount of confidential information data can be maintained constant even as the transaction of an item progresses in the supply chain SC.

[0033] The history management server 20 can further issue a tracing code QRt. The tracing code QRt is a two-dimensional code such as a QR code attached to the final product FP supplied by the supply chain SC. The tracing code QRt enables the consumer who has acquired the final product FP to check the transaction record. As an example, the tracing code QRt records a hash value calculated from the last block of the blockchain and an IP address or URL indicating the contact point for inquiries about the transaction record.

[0034] A consumer of the final product FP can view the transaction record of the final product FP by using a user terminal 50, such as a smartphone or tablet terminal, and a traceability confirmation app. Specifically, the user terminal 50 reads the tracing code QRt attached to the final product FP and sends a transaction record reference request along with a hash value to the history management server 20, which is the contact point for inquiries. Upon receiving the reference request, the history management server 20 extracts the item information and transaction record linked to the hash value and generates data to be provided. The history management server 20 transmits the generated data to the user terminal 50, which is the source of the reference request. A consumer of the final product FP can use the traceability confirmation app to open the data to be provided received from the history management server 20 and check the history of the transaction record.

[0035] Next, the information code CQ2 will be further described in detail with reference to FIGS.

[0036] As described above, the information code CQ2 is generated by a process of combining the public code Cd1 and the secret code Cd2 (see Figure 1). The public code Cd1 and the secret code Cd2 each record information using a two-dimensional array of white cells Cww and black cells Cbw. The public code Cd1 and the secret code Cd2 are two-dimensional codes with the same number of cells (version). Therefore, the information code CQ2, which is a combination of the public code Cd1 and the secret code Cd2, is also a two-dimensional code with the same number of cells as the public code Cd1 and the secret code Cd2.

[0037] The information code CQ2 includes white cells Cww, black cells Cbw, as well as white-filled cells Cwc and black-filled cells Cbc. The information code CQ2 holds both public and private information using a two-dimensional array of white cells Cww, black cells Cbw, white-filled cells Cwc, and black-filled cells Cbc. Each cell Ce in the information code CQ2 is determined based on the combination of white cells Cww and black cells Cbw in the public code Cd1 and the private code Cd2 (see Figure 3).

[0038] Specifically, a cell Ce where the public code Cd1 and the concealment code Cd2 are both black cells Cbw also becomes a black cell Cbw with the information code CQ2. Similarly, a cell Ce where the public code Cd1 and the concealment code Cd2 are both white cells Cww also becomes a white cell Cww with the information code CQ2. On the other hand, a cell Ce where the public code Cd1 is a black cell Cbw and the concealment code Cd2 is a white cell Cww becomes a solid black cell Cbc. Furthermore, a cell Ce where the public code Cd1 is a white cell Cww and the concealment code Cd2 is a black cell Cbw becomes a solid white cell Cwc.

[0039] The white cell Cwc has a white region wc surrounded by an outer black region bs. The shape of the white region wc is similar to that of the white cell Cwc, and is either square or rectangular. The white region wc is located in the center of the white cell Cwc and is concentric with the white cell Cwc. The outer black region bs surrounds the entire periphery of the white region wc.

[0040] The bullet cell Cbc has a bullet region bc surrounded by an outer white region ws. The shape of the bullet region bc is similar to the shape of the bullet cell Cbc, and is a square or rectangle. The bullet region bc is located in the center of the bullet cell Cbc and is concentric with the bullet cell Cbc. The outer white region ws surrounds the entire periphery of the bullet region bc.

[0041] The sizes of the white area wc and the black area bc are the same. For example, the length of one side of the white area wc and the black area bc is approximately one-half to three-quarters of the length of one side of the white cell Cwc and the black cell Cbc. The color of the white area wc and the outer white area ws is substantially the same as the color of the white cell Cww. Similarly, the color of the black area bc and the outer black area bs is substantially the same as the color of the black cell Cbw.

[0042] Here, the code reader 13 (see FIG. 2) of the distribution management system 110, which corresponds to the old management system, scans the center of each cell Ce when reading the information code CQ2 (see the dashed arrows in FIG. 3). Therefore, the code reader 13 distinguishes the white cell Cwc as a white cell Cww and the black cell Cbc as a black cell Cbw. As a result, the code reader 13 recognizes the information code CQ2 as a two-dimensional code that is substantially the same as the public code Cd1, and can read the public information. Here, in a QR code, information is written in a zigzag pattern starting from the bottom right cell Ce. Therefore, a typical code reader 13 that reads QR codes scans two columns of cells Ce together in a zigzag pattern. Even with this code reader 13, the center of each cell Ce is scanned, and the information code CQ2 is recognized as the same two-dimensional code as the public code Cd1.

[0043] Next, the details of the code generation process (code generation method) for generating the information code CQ2 explained above will be described below based on FIG. 4 and with reference to FIGS. 1 to 3.

[0044] In the code generation process, first, a public code Cd1 and a confidential code Cd2 are prepared. Specifically, in S11, the history management server 20 acquires the public code Cd1 by receiving it from the code output device 22. Next, in S12, the history management server 20 acquires a hash value that reflects the item information and transaction record, and prepares confidential information that mainly includes the hash value. Then, in S13, the history management server 20 generates a confidential code Cd2 that records the confidential information.

[0045] In S14, the history management server 20 combines the public code Cd1 and the confidential code Cd2 prepared in S11 to S13 by superimposing them based on a predetermined rule (see FIG. 3). As a result, an information code CQ2 is generated, which is a two-dimensional array of white cells Cww, black cells Cbw, white-centered cells Cwc, and black-centered cells Cbc. In S15, the information code CQ2 generated in this way is issued to the transactor TR.

[0046] Next, details of the code reading process (code reading method) for reading the concealment code Cd2 from the information code CQ2 will be described below based on FIGS. 5 and 6 and with reference to FIGS.

[0047] In S31 of the code reading process, the signal processing unit 41 determines the position and orientation of the information code CQ2 in the captured code image based on the detection of the finder pattern. In S32, the signal processing unit 41 applies preprocessing such as keystone correction and binarization to the area containing the information code CQ2 based on the information on the position and orientation of the information code CQ2, and prepares a processed image suitable for code reading (hereinafter referred to as corrected image Pc0, see Figure 6). The corrected image Pc0 is an image corrected to the shape of the information code CQ2 photographed from the front. In addition, in the corrected image Pc0, the gradation values of the entire image are adjusted so that the gradation values of the white cells Cww and the white areas wc, and the gradation values of the black cells Cbw and the black areas bc are approximately the same.

[0048] In S33, the signal processing unit 41 converts the white cells Cwc of the cells Ce of the information code CQ2 in the corrected image Pc0 into black cells Cbw, making the white cells Cwc distinguishable from the black cells Cbw. Specifically, the signal processing unit 41 performs image processing to fill in the white areas wc of the white cells Cwc with the black color of the outer black areas bs that surround the white areas wc, thereby generating a first filled-in image Pp1.

[0049] Furthermore, in S34, the signal processing unit 41 converts the dark cells Cbc of the cells Ce of the information code CQ2 in the first filled-in image Pp1 into white cells Cww, making the dark cells Cbc distinguishable from the white cells Cww. Specifically, the signal processing unit 41 generates a first inverted image Pi1 by inverting the brightness (black and white) of the colors in the first filled-in image Pp1. In the first inverted image Pi1, the dark regions bc become white regions obtained by inverting black and white (hereinafter referred to as inverted bright regions bci), and the outer white regions ws become black regions obtained by inverting black and white (hereinafter referred to as inverted dark regions wsi). The signal processing unit 41 performs image processing to fill the inverted bright regions bci with the black of the inverted dark regions wsi, thereby generating a second filled-in image Pp2. The signal processing unit 41 again inverts the brightness (black and white) of the colors in the second filled-in image Pp2, generating a second inverted image Pi2.

[0050] As a result of steps S33 and S34, the white cell Cwc and the black cell Cbc are respectively changed to the black cell Cbw and the white cell Cww, and the second inverted image Pi2 essentially becomes an image obtained by restoring the concealment code Cd2. In step S35, the signal processing unit 41 reads the concealment information from the restored concealment code Cd2, and the code reading process ends.

[0051] The code reading process may be performed by the history management server 20. In this embodiment, the code captured image or corrected image Pc0 is transmitted from the code scanner 23 to the history management server 20. The history management server 20 performs a process of reading the concealment code Cd2 from the received code captured image or corrected image Pc0.

[0052] In the embodiment described so far, in addition to the white cell Cww and the black cell Cbw, a white cell Cwc having a white area wc surrounded by an outer black area bs and a black cell Cbc having a black area bc surrounded by an outer white area ws are used. Therefore, even if the information code CQ2 is affected by light, it is unlikely that the white cell Cwc and the black cell Cbc will be difficult to distinguish from each other. As a result, failure to read the code can be reduced.

[0053] In addition, the use of the white cell Cwc and the black cell Cbc makes it possible to overlap the public code Cd1 and the concealment code Cd2 without using chromatic color cells or neutral gray cells Ce. This allows the information code CQ2 to be used while continuing to use a label printer 12 that only supports simple black-and-white printing. This means that it is no longer necessary to introduce a printer that supports grayscale or color output, which helps to reduce printing costs. As a result, it is possible to maintain both reading compatibility and code printing compatibility for the public code Cd1 and the concealment code Cd2.

[0054] Furthermore, in the information code CQ2 according to this embodiment, the white cell Cwc is determined as a white cell Cww when the public code Cd1 is read, and as a black cell Cbw when the confidentiality code Cd2 is read. On the other hand, the black cell Cbc is determined as a black cell Cbw when the public code Cd1 is read, and as a white cell Cww when the confidentiality code Cd2 is read. With this information code CQ2, the information code CQ2 with added confidentiality information can be operated while continuing to use the existing code reader 13. As described above, the improved compatibility of the traceability system 120 with the old system makes it possible to lower the barrier to introducing the traceability system 120.

[0055] Additionally, in this embodiment, the shape of the white area wc is similar to the shape of the white cell Cwc, and the shape of the black area bc is similar to the shape of the black cell Cbc. This makes it easy to generate image data for the information code CQ2, even if the information code CQ2 includes the white cell Cwc and the black cell Cbc. As a result, the processing load of the code generation process is reduced, enabling the information code CQ2 to be issued quickly.

[0056] In this embodiment, in the step of changing the white cells Cwc to black cells Cbw, a first filled image Pp1 is generated by filling the white regions wc with the dark color of the outer black regions bs. Furthermore, in the step of changing the black cells Cbc to white cells Cww, a first inverted image Pi1 is prepared by inverting the lightness and darkness of the first filled image Pp1, and a second filled image Pp2 is generated by filling the inverted light regions bci of the first inverted image Pi1 with the dark color of the inverted dark regions wsi. Then, a second inverted image Pi2 is generated by inverting the lightness and darkness of the second filled image Pp2. As described above, the image processing of sequentially filling the white cells Cww and the black cells Cbw can speed up the process of restoring the confidentiality code Cd2 from the information code CQ2. As a result, confidential information can be quickly read from the information code CQ2.

[0057] In the above embodiment, the signal processing unit 41 corresponds to a "processing unit" that performs the code reading method, the public code Cd1 corresponds to a "first code," and the concealment code Cd2 corresponds to a "second code." Furthermore, the white cell Cww corresponds to a "light cell," the black cell Cbw corresponds to a "dark cell," the middle white cell Cwc corresponds to a "medium-light cell," and the middle black cell Cbc corresponds to a "medium-dark cell." Furthermore, the middle white area wc corresponds to a "medium-light area," the middle black area bc corresponds to a "medium-dark area," the outer white area ws corresponds to an "outer light area," and the outer black area bs corresponds to an "outer dark area."

[0058] Further technical ideas that can be understood from the embodiments described above are described below as Supplementary Notes 1 and 2. (Appendix 1) A code generating device that generates an information code (CQ2) that is a combination of a first code (Cd1) and a second code (Cd2) that record information using a two-dimensional array of a plurality of cells (Ce), a code preparation unit (S11 to S13) that prepares the first code and the second code; a code synthesis unit (S14) that generates the information code by synthesizing the first code and the second code, The code synthesis unit The cell at a position where both the first code and the second code are light cells (Cww) is defined as the light cell, The cell at a position where both the first code and the second code are dark cells (Cbw) is defined as the dark cell, The cell at the position where the first code is the light cell and the second code is the dark cell is defined as a medium light cell (Cwc) in which a medium light area (wc) is surrounded by an outer dark area (bs), A code generation device that sets the cell at a position where the first code is the dark cell and the second code is the light cell to a medium dark cell (Cbc) in which a medium dark area (bc) is surrounded by an outer light area (ws). (Appendix 2) A code reading device that reads a second code from an information code (CQ2) that is a combination of a first code (Cd1) and a second code (Cd2) that record information using a two-dimensional array of a plurality of cells (Ce), comprising: an image acquisition unit (S31) that acquires a code image showing the information code; an image conversion unit (S33, S34) that converts, among the cells of the information code, a medium-light cell (Cwc) having a medium-light area (wc) surrounded by an outer dark area (bs) into a dark cell (Cbw), and converts, among the cells (Ce) of the information code, a medium-dark cell (Cbc) having a medium-dark area (bc) surrounded by an outer light area (ws) into a light cell (Cww); A code reading device comprising: In the above embodiment, the history management server 20 corresponds to the "code generating device", and the history management server 20 or the code scanner 23 corresponds to the "code reading device".

[0059] (Other embodiments) Although one embodiment of the present disclosure has been described above, the present disclosure should not be construed as being limited to the above embodiment, and can be applied to various embodiments and combinations within the scope that does not deviate from the gist of the present disclosure.

[0060] The shapes and sizes of the black and white regions bc and wc are not limited to those of the above embodiment and may be modified as appropriate. For example, when the information code CQ2 is prepared as image data, one cell is composed of multiple rectangular pixels px arranged vertically and horizontally. Specifically, in Modification 1 shown in FIG. 7, one cell is composed of an array of three pixels px arranged vertically and horizontally. In the white cell Cwc of Modification 1, the central pixel px forms the black and white region bc, and the eight pixels px surrounding the central pixel px form the outer black region bs. Similarly, in the black cell Cbc, the central pixel px forms the black and white region bc, and the eight pixels px surrounding the central pixel px form the outer white region ws.

[0061] In Modification 2 shown in Figure 8, one cell is composed of an array of many (e.g., six) pixels px. In Modification 2, the white area wc and the black area bc are formed in a cross shape rather than a rectangle. As in Modifications 1 and 2 above, the shape and size of the white area wc and the black area bc may be changed as appropriate depending on the number and shape of the pixels px that make up each cell. Furthermore, the shape and size of the white area wc and the black area bc may be changed as appropriate depending on the resolution and individual dot shape of the label printer 12, or the resolution and individual display pixel shape of the display device, etc.

[0062] In Modification 3 shown in Fig. 9, the white region wc and the black region bc are square-shaped, rotated 45° with respect to the outer edges of the white cell Cwc and the black cell Cbc, in other words, diamond-shaped. In Modification 4 shown in Fig. 10, the white region wc and the black region bc are circular and concentric with the white cell Cwc and the black cell Cbc.

[0063] Furthermore, in Modification 5, the centers of the white area wc and the black area bc are offset from the centers of the white cell Cwc and the black cell Cbc. Furthermore, in Modification 6, the black area bc and the black area wc have different shapes and sizes. Additionally, in Modification 7, the outer black area bs and the outer white area ws have shapes that partially surround the white area wc and the black area bc. As in Modification 7, if image processing is possible to fill in the white area wc and the black area bc, the outer black area bs and the outer white area ws do not need to surround the entire white area wc and the black area bc.

[0064] In the above embodiment, the light colors forming the white cell Cww, the central white area wc, and the outer white area ws do not have to be strictly white. For example, the color of the base material of the label or the like on which the information code CQ2 is printed (e.g., very light gray or ivory) can correspond to the light color. Similarly, the dark colors forming the black cell Cbw, the central black area bc, and the outer black area bs do not have to be strictly black. For example, the color of the ink used in the label printer 12 (e.g., dark navy blue or dark green) can correspond to the dark color.

[0065] The public code Cd1 and the confidentiality code Cd2 are not limited to QR codes. Two-dimensional codes different from QR codes may be used as the first code and the second code and combined into the information code. Furthermore, when QR codes are used as each code, the error correction capabilities (error correction levels) may be different from each other. As an example, the error correction level of the confidentiality code Cd2 is set higher than the error correction level of the public code Cd1.

[0066] The information code CQ2 according to the present disclosure may be used by a system different from the distribution management system 110 and the traceability system 120. Furthermore, the information recorded in the first code and the second code that are the basis of the information code is not limited to the above-mentioned public information and confidential information, and may be changed as appropriate depending on the use of the information code.

[0067] In the above embodiment, a tracing code QRt is issued and attached to the final product FP, separate from the information code CQ2 used in the supply chain SC. However, the information code CQ2 may be used as the tracing code QRt. In this case, the traceability confirmation application performs the above-described code reading process and provides the user terminal 50 with a function for reading the concealment code Cd2. Furthermore, the final product FP supplied by the supply chain SC may be changed as appropriate. For example, various items such as automobiles, batteries, semiconductors, fresh produce, seafood, food, flowers, pharmaceuticals, and chemicals can be managed by the traceability system 120.

[0068] The hash function used in the history management server 20 is a cryptographic hash function, which has the property that it never outputs the same hash value from different inputs and that it is virtually impossible to guess the input from the output hash value. For example, instead of the above-mentioned SHA-256, encryption algorithms such as SHA-1, SHA-2, and SHA-3 may be used as appropriate in accordance with the output length (number of bits) that can be recorded in the confidential information in the confidentiality code Cd2. Furthermore, the code generation process performed in the history management server 20 may be performed by a code output device 22 or the like on the edge side. In such a configuration, the code output device 22 corresponds to the "code generation device."

[0069] In the above embodiment, the functions provided by the history management server, code scanner, etc. can be provided by software and hardware that executes it, software only, hardware only, or a combination of these. When such functions are provided by electronic circuits as hardware, each function can also be provided by digital circuits including multiple logic circuits, or analog circuits.

[0070] The processing unit (signal processing unit) in the above embodiment may be configured to include at least one arithmetic core such as a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit).Furthermore, the processing unit may be configured to further include an FPGA (Field-Programmable Gate Array), an NPU (Neural network Processing Unit), an IP core with other dedicated functions, etc.

[0071] The form of the non-transitory tangible storage medium employed as each storage unit in the above embodiments and storing each program related to code generation and code reading of the present disclosure may be modified as appropriate. For example, the storage medium is not limited to a configuration mounted on a circuit board, but may be provided in the form of a memory card or the like, inserted into a slot, and electrically connected to a computer bus. Furthermore, the storage medium may be an optical disk or hard disk drive from which the program is copied to the computer.

[0072] The controller and methods described herein may be implemented by a special-purpose computer comprising a processor programmed to perform one or more functions embodied in a computer program. Alternatively, the apparatus and methods described herein may be implemented by special-purpose hardware logic circuitry. Alternatively, the apparatus and methods described herein may be implemented by one or more special-purpose computers comprising a processor executing a computer program in combination with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory storage medium.

Claims

1. An information code formed by combining a first code (Cd1) and a second code (Cd2) that record information by a two-dimensional array of a plurality of cells (Ce), A light cell (Cww), a dark cell (Cbw); A medium-light cell (Cwc) in which a medium-light region (wc) surrounded by an outer dark region (bs) is formed; A medium-dark cell (Cbc) in which a medium-dark region (bc) surrounded by an outer light region (ws) is formed; Contains the information code.

2. the medium-light cell is identified as the light cell when reading the first code, and is identified as the dark cell when reading the second code; 2. The information code according to claim 1, wherein the medium-dark cells are identified as the dark cells when the first code is read, and are identified as the light cells when the second code is read.

3. the shape of the intermediate-light color region is similar to the shape of the intermediate-light color cell; 3. The information code according to claim 1, wherein the shape of the medium-dark color area is similar to the shape of the medium-dark color cell.

4. A first code (Cd1) and a second code (Cd2) for recording information by a two-dimensional array of a plurality of cells (Ce) are prepared (S11 to S13); An information code (CQ2) is generated by combining the first code and the second code (S14). The process performed by at least one processing unit (31) includes the steps of: In the step of combining the first code and the second code, The cell at a position where both the first code and the second code are light cells (Cww) is defined as the light cell, The cell at a position where both the first code and the second code are dark cells (Cbw) is defined as the dark cell, The cell at the position where the first code is the light cell and the second code is the dark cell is defined as a medium light cell (Cwc) in which a medium light area (wc) is surrounded by an outer dark area (bs), A code generation method in which the cell at a position where the first code is the dark cell and the second code is the light cell is defined as a medium dark cell (Cbc) in which a medium dark area (bc) is surrounded by an outer light area (ws).

5. A code reading method for reading a second code from an information code (CQ2) obtained by combining a first code (Cd1) and a second code (Cd2) that record information by a two-dimensional array of a plurality of cells (Ce), the method comprising: Among the cells (Ce) of the information code, a medium-light cell (Cwc) having a medium-light area (wc) surrounded by an outer dark area (bs) is designated as a dark cell (Cbw) (S33). Among the cells (Ce) of the information code, a medium-dark cell (Cbc) having a medium-dark area (bc) surrounded by an outer light area (ws) is designated as a light cell (Cww) (S34). A code reading method including the steps of:

6. In the step of converting the intermediate light color cells into the dark color cells, a first filled image (Pp1) is generated by filling the intermediate light color region with the dark color of the outer dark color region; In the step of changing the medium dark color cell to the light color cell, generating a first inverted image (Pi1) by inverting the brightness of the colors in the first filled image; A second filled image (Pp2) is generated by filling in an inverted light color area (bci) in which the brightness of the middle dark color area is inverted in the first inverted image with the dark color of an inverted dark color area (wsi) in which the brightness of the outer light color area is inverted; 6. The code reading method according to claim 5, further comprising generating a second inverted image (Pi2) by inverting the brightness of the second filled image.

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