Information code, information code generating device, and information code generating program

Abstract

An information code (CD) records a public code (CP) and a hidden code (CH) by superimposing at least either a first symbol or a second symbol in a common two-dimensional area by arranging cells (WHC, BLC, RDC, CYC) for encoding the codes. The information code (CD) displays: cells in which the first symbol is encoded in both codes (CP, CH) in black; cells in which the second symbol is embedded in both codes (CP, CH) in white; cells (RDC) in which the first symbol is embedded in the public code (CP) and the second symbol is embedded in the hidden code (CH) in red; and cells in which the second symbol is embedded in the public code (CP) and the first symbol is embedded in the hidden code (CH) in cyan so as to be recognized by a reader with a higher brightness than the cells displayed in red under white light and with a lower brightness than the cells displayed in red under red light.

Description

Information code, information code generation device, and information code generation program CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2023-146447 filed in Japan on September 8, 2023, and the contents of the original application are incorporated by reference in their entirety.

[0002] The disclosure of this specification relates to a technology for realizing highly convenient information codes.

[0003] Patent Document 1 discloses an information code that can store a large amount of information by using ink with different color wavelengths or magnetic properties.

[0004] Japanese Patent Application Laid-Open No. 2023-101436

[0005] While the information code of Patent Document 1 allows for a large amount of information to be stored, it does not take into consideration the possibility of recording multiple types of information in the same area by superimposing them, and there is room for improvement in terms of convenience.

[0006] One of the purposes of the disclosure of this specification is to provide an information code, an information code generating device, and an information code generating program that are highly convenient to read.

[0007] One aspect disclosed herein is an information code that is decoded according to brightness recognized by a reader, in which a first code indicating first information and a second code indicating second information are recorded superimposed in a common two-dimensional area by arranging cells that encode at least one of a first symbol and a second symbol with the first code and the second code, respectively; cells in which the first symbol is encoded with the first code and the first symbol is encoded with the second code are displayed in a first color that becomes black through binarization processing; cells in which the second symbol is encoded with the first code and the second symbol is encoded with the second code are displayed in a second color that becomes white through binarization processing; cells in which the first symbol is encoded with the first code and the second symbol is encoded with the second code are displayed in a first auxiliary color; A second symbol is coded in the first code, and a cell in which the first symbol is coded in the second code is displayed in a second auxiliary color that is recognized by a reader with higher brightness under white light than when displayed in the first auxiliary color, and that is recognized by a reader with lower brightness under light of the first auxiliary color than when displayed in the first auxiliary color.

[0008] Another disclosed aspect is an information code generating device that includes at least one processor and generates an information code that is configured to be readable by a reader by performing a binarization process on brightness, wherein the at least one processor generates an information code that records, superimposed in a common two-dimensional area, a public code representing public information by arranging a plurality of cells in which either a first symbol or a second symbol that can be distinguished by the binarization process is embedded, and a confidentiality code representing confidential information by arranging a plurality of cells in which either the first symbol or the second symbol is embedded, and wherein, in generating the information code, the at least one processor: sets cells in which the first symbol is embedded in the public code and in which the first symbol is embedded in the confidentiality code to be displayed in black; sets cells in which the second symbol is embedded in the public code and in which the second symbol is embedded in the confidentiality code to be displayed in white; sets cells in which the first symbol is embedded in the public code and in which the second symbol is embedded in the confidentiality code to be displayed in a first auxiliary color; A cell in which the second symbol is embedded in the public code and the first symbol is embedded in the confidential code is set to be displayed in a second supplementary color that is recognized by a reader with higher brightness under white light than when displayed in the first supplementary color and is recognized by a reader with lower brightness under light of the first supplementary color than when displayed in the first supplementary color.

[0009] Another disclosed aspect is an information code generation program that generates an information code configured to be readable by a reader by performing a binarization process on brightness, the information code generation program being configured to cause at least one processor to execute the following: generating an information code in which a public code representing public information is recorded by arranging a plurality of cells in which either a first symbol or a second symbol that can be distinguished by the binarization process is embedded, and a confidentiality code representing confidential information is recorded by arranging a plurality of cells in which either the first symbol or the second symbol is embedded, superimposed in a common two-dimensional area; and in generating the information code, the program performs the following steps: setting a cell in which the first symbol is embedded in the public code and in which the first symbol is embedded in the confidentiality code to be displayed in black; setting a cell in which the second symbol is embedded in the public code and in which the second symbol is embedded in the confidentiality code to be displayed in white; setting a cell in which the first symbol is embedded in the public code and in which the second symbol is embedded in the confidentiality code to be displayed in a first auxiliary color; The cell in which the second symbol is embedded in the public code and the first symbol is embedded in the secret code is configured to be displayed in a second auxiliary color that is recognized by a reader under white light with a higher brightness than the display in the first auxiliary color and is recognized by a reader under light of the first auxiliary color with a lower brightness than the display in the first auxiliary color.

[0010] According to these aspects, the second auxiliary color can be recognized by a reader under white light with higher brightness than the display of the first auxiliary color. Therefore, when a reader reads an information code under white light without using, for example, an optical filter, the brightness threshold in the binarization process can be set between the first auxiliary color and the second auxiliary color. Furthermore, cells of the first color and the first auxiliary color that can be recognized as black can be recognized as recording a first symbol, and cells of the second color and the second auxiliary color that can be recognized as white can be recognized as recording a second symbol. In other words, the information code is substantially read as the first code (or, for example, a disclosure code).

[0011] On the other hand, the second auxiliary color can be recognized by a reader under the first auxiliary color light at a lower luminance than the display under the first auxiliary color. Therefore, under the first auxiliary color light (including the case where the reader reads the information code through an optical filter that reproduces the first auxiliary color light), the roles of the first and second auxiliary colors are reversed. More specifically, the cells of the first color that can be recognized as black and the cells of the second auxiliary color can be recognized as recording the first symbol, and the cells of the second color that can be recognized as white and the cells of the first auxiliary color can be recognized as recording the second symbol. In other words, the information code is essentially read as a second code (or, for example, a secret code).

[0012] Therefore, it is possible to select the desired information to be read from the first code (or, for example, a public code) and the second code (or, for example, a secret code) recorded in a common two-dimensional area simply by the presence or absence of an optical filter, without the need to prepare completely separate readers for each code. Therefore, it is possible to dramatically improve the convenience of reading.

[0013] Note that the symbols in parentheses included in the claims etc. are intended to exemplify the correspondence with the parts of the embodiments described below, and are not intended to limit the technical scope.

[0014] 1 is a diagram showing a public code, a confidential code, and an information code after synthesis. FIG. 2 is a diagram for explaining a code generation device and a code reader. A flowchart showing an example of a code generation process. FIG. 3 is a diagram showing synthesis rules. A graph showing an example of luminance distribution without an optical filter. FIG. 4 is a diagram explaining recognition of a white cell under application of a red color filter. FIG. 5 is a diagram explaining recognition of a black cell under application of a red color filter. FIG. 6 is a diagram explaining recognition of a red cell under application of a red color filter. FIG. 7 is a diagram explaining recognition of a cyan cell under application of a red color filter. FIG. 8 is a diagram explaining recognition of an information code under application of a red color filter. A graph showing an example of luminance distribution under application of a red color filter. FIG. 9 is a diagram explaining recognition of a white cell under application of a green color filter. FIG. 10 is a diagram explaining recognition of a black cell under application of a green color filter. FIG. 11 is a diagram explaining recognition of a red cell under application of a green color filter. FIG. 12 is a diagram explaining recognition of a cyan cell under application of a green color filter. A graph showing an example of luminance distribution under application of a green color filter. A diagram showing a traceability system together with a distribution management system. A diagram showing a public code, a confidential code, and an information code after synthesis. A diagram showing a public code, a confidential code, and an information code after synthesis.

[0015] Hereinafter, several embodiments will be described with reference to the drawings. Note that corresponding components in each embodiment are given the same reference numerals, and redundant description may be omitted. When only a portion of the configuration is described in each embodiment, the configuration of another embodiment described previously can be applied to the remaining portion of the configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations of several embodiments can also be partially combined together even if not explicitly stated, as long as there is no particular problem with the combination.

[0016] First Embodiment As shown in FIG. 1 , an information code CD according to a first embodiment of the present disclosure is generated by a process of combining two two-dimensional codes. The information code CD stores the two two-dimensional codes superimposed on a common two-dimensional area. The two-dimensional code that forms the basis of the information code CD is, for example, a QR Code (registered trademark), and stores information using a two-dimensional array of multiple cells. The information code CD may be an image display object displayed on an electronic display device such as a display 1d.

[0017] The information code CD is generated by combining a public code CP and a confidential code CH by a code generation device 1 shown in Fig. 2. When the information code CD is read using a normal code reader 2 and reading method, the information code CD is recognized as the public code CP. In this case, the information recorded in the public code CP (hereinafter referred to as public information) is read. On the other hand, the confidential code CH can be read by reading the information code CD with the code reader 2 through a predetermined optical filter 23. In this case, the information recorded in the confidential code CH (hereinafter referred to as confidential information) is read.

[0018] For example, the information code CD may be displayed on product price plates, menus, etc. in retail stores or restaurants. In this case, the public information that can be read by a customer using a normal reading method without using the optical filter 23, such as their own smartphone, may be information useful to the customer, such as the address of a web page that describes the product's functions, menu details, etc. On the other hand, the confidential information may be information useful to the retail store or restaurant, such as information about the product manager, inventory information, ordering information, etc.

[0019] The code reader 2 is a reading device that reads either public information or confidential information by reading the information code CD. The code reader 2 may be a general-purpose mobile terminal such as a smartphone, or a dedicated terminal such as a handheld terminal used in logistics, retail, or manufacturing. In this case, the code reader 2 includes a sensor 2a, a processor 2b, a RAM 2c, and a display 2d. The sensor 2a may be an imaging sensor formed by a two-dimensional array of CCD elements that detect light. The imaging sensor is capable of reading information recorded in a two-dimensional area with high resolution.

[0020] The processor 2b includes at least one type of core selected from the group consisting of a central processing unit (CPU), a graphics processing unit (GPU), and a reduced instruction set computer (RISC)-CPU. The processor 2b performs a code reading process to decode the signal read by the image sensor in accordance with predetermined rules, and acquires public or confidential information recorded on the information code CD. The processor 2b may display the acquired information on the display 2d, store it in an internal storage medium, or transmit it to an external device.

[0021] The code reader 2 decodes the information code CD according to the brightness. The code reader 2 performs binarization processing on the two-dimensional area detected by the sensor 2a based on the brightness threshold LT to read the information code CD. That is, an area where a brightness higher than the brightness threshold LT is detected can be recognized as substantially white. An area where a brightness lower than the brightness threshold LT is detected can be recognized as substantially black. The brightness threshold TL may be, for example, the average brightness of the two-dimensional area where the information code CD is displayed.

[0022] Furthermore, the code reader 2 may include an optical filter unit 3 for switching the information to be read between the public code CP and the confidential code CH. The optical filter unit 3 may be attached to the exterior of the sensor 3a and configured to be able to switch between the exposed information and the filter applied state using a switch, lever, or the like. The exposed state is a state in which the sensor 3a is optically exposed to the outside (i.e., a state without the optical filter 23). The filter applied state is a state in which the sensor 3a detects light through the optical filter 23. On the other hand, the code reader 2 does not necessarily have to include the optical filter unit 3. The optical filter 23 may be provided separately from the code reader 2.

[0023] The code generation device 1 is a generation device that generates an information code CD. The code generation device 1 may be, for example, a general-purpose mobile terminal such as a smartphone, a personal computer, or a business computer used in logistics, retail, or manufacturing. The code generation device 1 is mainly configured as a computer including a processor 1a, RAM 1b, storage unit 1c, an input / output interface, and a bus connecting these. The processor 1a is hardware for arithmetic processing coupled to the RAM 1b. The processor 1a includes at least one type of core, such as a central processing unit (CPU), a graphics processing unit (GPU), or a reduced instruction set computer (RISC)-CPU. The processor 1a accesses the RAM 1b to execute various processes related to the information code CD. The storage unit 1c stores an information code generation program for causing the processor 1a to execute the information code generation method disclosed herein.

[0024] The information code CD and a method for generating the information code CD will now be described in detail. An example of a method for generating the information code CD is shown in the flowchart of Fig. 3. The code generation process shown in S11 to S16 of Fig. 3 is realized by the processor 1a of the code generation device 1 executing an information code generation program.

[0025] In S11, the code generation device 1 prepares public information. The public information may be information input or selected by a user operating the code generation device 1. The public information may also be information acquired from an external device communicably connected to the code generation device 1. After processing S11, the process proceeds to S12.

[0026] In S12, the code generation device 1 generates a public code CP based on the public information. The public code CP is a QR code represented by a two-dimensional array of two-color cells, for example, white cells WHC and black cells BLC. In the two-dimensional array of two-color cells, it may be assumed that white cells WHC are converted to 0 and black cells BLC are converted to 1. In other words, a white cell WHC may be a 0 encoded in the form of a cell, and a black cell BLC may be a 1 encoded in the form of a cell. After processing S12, the process proceeds to S13.

[0027] In S13, the code generation device 1 prepares secret information. The secret information may be information input or selected by a user operating the code generation device 1. The secret information may also be information obtained from an external device communicably connected to the code generation device 1. After processing in S13, the process proceeds to S14.

[0028] In S14, the code generation device 1 generates a confidentiality code CH based on the confidential information. The confidentiality code CH is a QR code expressed by a two-dimensional array of two colored cells, for example, white cells WHC and black cells BLC. The version of the confidentiality code CH is preferably the same as that of the public code CP, but may be different. The version indicates the size of the code, and the larger the version value, the larger the code size. After processing S14, proceed to S15.

[0029] In S15, the code generation device 1 combines the public code CP and the confidentiality code CH. That is, the public code CP and the confidentiality code CH are stored superimposed in a common two-dimensional area as an information code CD. After processing in S15, the process proceeds to S16.

[0030] In S16, the code generation device 1 issues the synthesized information code CD. "Issuing" here may mean displaying the information code CD on a display 1d attached to the code generation device 1. "Issuing" may also mean transmitting the information code CD to an external display 1d on which the information code CD is to be displayed or to a computer controlling the display 1d. The series of processes ends with S16.

[0031] The composition process of S15 and the reading of the composed information code CD will now be described in more detail. The color of each cell of the composed information code CD is determined automatically according to a predetermined composition rule. The composition rule is, for example, the rule shown in FIG. 4.

[0032] According to the composition rule of Fig. 4, when the public code CP is a black cell BLC and the concealment code CH is a black cell BLC in the cells that are superimposed on each other, the information code CD after composition becomes a black cell BLC. When the public code CP is a white cell WHC and the concealment code CH is a white cell WHC in the cells that are superimposed on each other, the information code CD after composition becomes a white cell WHC. When the public code CP is a black cell BLC and the concealment code CH is a white cell WHC in the cells that are superimposed on each other, the information code CD after composition becomes a red cell RDC. When the public code CP is a white cell WHC and the concealment code CH is a black cell BLC in the cells that are superimposed on each other, the information code CD after composition becomes a cyan cell CYC.

[0033] This composition rule is set on the assumption that the optical filter 23 used in reading is a red color filter 23a. The red color filter 23a is a wavelength-selective long-pass filter configured to transmit almost all red light in the 620 to 750 nm range and block green and blue light with shorter wavelengths. The red color filter 23a may also be a band-pass filter that transmits only red light in the 620 to 750 nm range.

[0034] The additional colors added in the composition rules, namely red and cyan, are selected so that when the code reader 2 performs the above-mentioned binarization process as a normal reading method, the judgment results are reversed depending on whether or not the red color filter 23a is present.

[0035] 5 shows the luminance distribution and luminance threshold LT of the information code CD for each cell when, for example, the red color filter 23a is not present, i.e., when the information code CD is read under white light. The luminance under white light is perceived to be increasingly higher in the order of black cell BLC, red cell RDC, cyan cell CYC, and white cell WHC. That is, the luminance under white light is perceived to be increasingly higher in the order of luminance LB corresponding to black, luminance LR corresponding to red, luminance LC corresponding to cyan, and luminance LW corresponding to white. Furthermore, the luminance difference between red cell RDC and cyan cell CYC is greater than the luminance difference between black cell BLC and red cell RDC and the luminance difference between cyan cell CYC and white cell WHC. Conversely, the combination of additional colors (also called supplementary colors) is set so that this relationship is established.

[0036] Then, the brightness threshold TL based on the average brightness of the two-dimensional region is determined between the brightness LR corresponding to red and the brightness LC corresponding to cyan. That is, when reading without the red color filter 23a, the red cell RDC is recognized as the black cell BLC, and the cyan cell CYC is recognized as the white cell WHC. Based on the composition rule of FIG. 3, the black cell BLC and the red cell RDC of the information code CD correspond to the black cell BLC of the disclosure code CP. The white cell WHC and the cyan cell CYC of the information code CD correspond to the white cell WHC of the disclosure code CP. Therefore, when the code reader 2 reads the information code CD in a sensor exposure state without the red color filter 23a, it can obtain substantially the same results as reading the disclosure code CP, which has a two-color configuration of the white cell WHC and the black cell BLC.

[0037] Next, reading with the filter applied will be described with reference to Figures 6 to 11. Figures 6 to 9 explain what color the cell is recognized as by the code reader 2 when white light is reflected by the four color cells and then transmitted through the red color filter 23a. Note that the white light in this embodiment is also called natural light, and may be, for example, sunlight.

[0038] When the information code CD is displayed on the transmissive liquid crystal display 1d, it is sufficient to assume that white light is transmitted through the liquid crystal panel instead of being reflected, and the color of the recognized cell can be understood on substantially the same principle. Furthermore, the recognition mode through the red color filter 23a can be said to be substantially the same as the mode in which the information code CD printed on a print medium is read under red light.

[0039] 6, red light, green light, and blue light are reflected from the white cell WHC. Of the reflected red, green, and blue light, only the red light passes through the red color filter 23a. Therefore, the white cell WHC can be recognized by the code reader 2 as red or a brightness LR corresponding to red.

[0040] 7, red light, green light, and blue light are all absorbed by the black cell BLC, so that the black cell BLC can be recognized by the code reader 2 as black or at a brightness LB corresponding to black.

[0041] 8, only the red light among the red, green, and blue light is reflected. The red light is then transmitted through the red color filter 23a. Therefore, the red cell RDC can be recognized by the code reader 2 as red or a brightness LR corresponding to red.

[0042] 9, the cyan cell CYC reflects the green light and the blue light out of the red light, green light, and blue light, respectively. The reflected green light and blue light are then absorbed by the red color filter 23a. Therefore, the cyan cell CYC can be recognized by the code reader 2 as black or a brightness LB corresponding to black.

[0043] 10, an information code CD having four color cells including white, black, and two auxiliary colors can be recognized as being composed of two color cells, black cells BLC and red cells RDC, when a red color filter 23a is used. More specifically, the black cells BLC and cyan cells CYC can be recognized as black or at a brightness LB corresponding to black, and the white cells WHC and red cells RDC can be recognized as red or at a brightness LR corresponding to red.

[0044] 11 shows the luminance distribution and luminance threshold LT of the information code CD for each cell when, for example, a red color filter 23a is present. The luminance distribution is divided into two values: luminance LB corresponding to black and luminance LR corresponding to red. Therefore, the luminance threshold LT in the binarization process is set between luminance LB corresponding to black and luminance LR corresponding to red.

[0045] As a result, when reading with the red color filter 23a, the black cells BLC and cyan cells CYC are recognized as black cells BLC, and the white cells WHC and red cells RDC are recognized as white cells WHC. Based on the composition rule of Figure 4, the black cells BLC and cyan cells CYC of the information code CD correspond to the black cells BLC of the concealment code CH. The white cells WHC and red cells RDC of the information code CD correspond to the white cells WHC of the concealment code CH. Therefore, when the code reader 2 reads the information code CD with the red color filter 23a applied, it can obtain substantially the same results as reading the two-color concealment code PH consisting of white cells WHC and black cells BLC.

[0046] Next, a case where the above-mentioned information code CD is read using a green color filter 24 instead of the red color filter 23a will be described with reference to Figures 12 to 16. Figures 12 to 15 explain what color the cells will be recognized as by the code reader 2 when white light is reflected by the four color cells and then transmitted through the green color filter 24.

[0047] 12, red light, green light, and blue light are reflected, respectively. Of the reflected red light, green light, and blue light, only green light passes through the green color filter 24. Therefore, the white cell WHC can be recognized by the code reader 2 as green or a luminance LG corresponding to green.

[0048] 13, red light, green light, and blue light are all absorbed, so that the black cell BLC can be recognized by the code reader 2 as black or at a brightness LB corresponding to black.

[0049] 14, only the red light among the red, green, and blue light is reflected. The red light is then absorbed by the green color filter 24. Therefore, the red cell RDC can be recognized by the code reader 2 as black or at a brightness LB corresponding to black.

[0050] 15, the green light and the blue light out of the red light, green light, and blue light are reflected, respectively. The green light out of the reflected green light and blue light is transmitted through the green color filter 24, and the blue light is absorbed by the green color filter 24. Therefore, the cyan cell CYC can be recognized by the code reader 2 as green or a luminance LG corresponding to green.

[0051] Therefore, the information code CD having four color cells can be recognized as being composed of two color cells, black cells BLC and green cells GRC, when the green color filter 24 is used. More specifically, the black cells BLC and red cells RDC can be recognized as black or at a brightness LB corresponding to black, and the white cells WHC and cyan cells CYC can be recognized as green or at a brightness LG corresponding to green.

[0052] 16 shows the luminance distribution and luminance threshold LT of the information code CD for each cell when, for example, a green color filter 24 is present. The luminance distribution is divided into two values: luminance LB corresponding to black and luminance GL corresponding to green. Therefore, the luminance threshold LT in the binarization process is set between luminance LB corresponding to black and luminance LG corresponding to green.

[0053] As a result, when reading with the green color filter 24, the black cells BLC and red cells RDC are recognized as black cells BLC, and the white cells WHC and cyan cells CYC are recognized as white cells WHC. Therefore, when the code reader 2 reads the information code CD through the green color filter 24, it is possible to obtain substantially the same results as when reading the public code CP, which has a two-color configuration of white cells WHC and black cells BLC.

[0054] 5 and 16, when reading with the green color filter 24, the difference between the brightness threshold value TL and the actually detected brightness value is greater than when reading in an exposed state without the optical filter 23. Therefore, when reading the public code CP, using the green color filter 24 can reduce erroneous recognition of cells compared to when reading in an exposed state.

[0055] In the first embodiment, the "code generation device 1" corresponds to the "information code generation device." The "code reader 2" corresponds to the "reader." The "public code CP" corresponds to the "first code," and the "privacy code CH" corresponds to the "second code." The "public information" corresponds to the "first information," and the "privacy information" corresponds to the "second information." "0" corresponds to the "first symbol," and "1" corresponds to the "second symbol." "Red" corresponds to the "first supplementary color," and "cyan" corresponds to the "second supplementary color."

[0056] According to the first embodiment described above, the second auxiliary color can be recognized by the code reader 2 under white light with a higher brightness than the first auxiliary color. Therefore, when the code reader 2 reads the information code CD under white light without using, for example, the optical filter 23, the brightness threshold TL in the binarization process can be set between the first and second auxiliary colors. Furthermore, the black cells BLC and the first auxiliary color cells RDC can be recognized as recording the first symbol, and the white cells WHC and the second auxiliary color cells CYC can be recognized as recording the second symbol. In other words, the information code CD is essentially read as the public code CP.

[0057] On the other hand, the second auxiliary color can be recognized by the code reader 2 under the first auxiliary color light with a lower luminance than the display of the first auxiliary color. Therefore, under the first auxiliary color light (including the case where the code reader 2 reads the information code CD through the optical filter 23 that reproduces the image under the first auxiliary color light), the roles of the first and second auxiliary colors are reversed. More specifically, the black cells BLC and the second auxiliary color cells CYC can be recognized as recording the first symbol, and the white cells WHC and the first auxiliary color cells RDC can be recognized as recording the second symbol. In other words, the information code CD is essentially read as the concealment code CH.

[0058] Therefore, it is not necessary to prepare completely different code readers 2 for reading the information to be read from the public code CP and the confidential code CH, which are recorded superimposed on a common two-dimensional area, and it becomes possible to select, for example, the information to be read, simply by the presence or absence of the optical filter 23. Therefore, the convenience of reading can be dramatically improved.

[0059] Furthermore, according to the first embodiment, the first supplementary color is one of the three primary colors of light. The second supplementary color is a color obtained by additively mixing the remaining two primary colors of light. This color combination allows for a large difference in luminance between the first and second supplementary colors under white light. Furthermore, by significantly differentiating the hues of the first and second supplementary colors, the perceived luminance reversal effect between white light and the first supplementary color is enhanced. As a result, even when using four color cells WHC, BLC, RDC, and CYC, misrecognition of the information code CD by the code reader 2 can be suppressed.

[0060] In the first embodiment, the first auxiliary color is red and the second auxiliary color is cyan. This combination maximizes the luminance difference between the first and second auxiliary colors under white light, even among combinations using the three primary colors of light. This further improves the effect of suppressing erroneous recognition.

[0061] According to the first embodiment, the information code CD is an image displayed on an electronic display device (e.g., display 1d). The information code CD displayed on the electronic display device can relatively easily represent the luminance difference between the first and second auxiliary colors.

[0062] Second Embodiment As shown in Fig. 17, the second embodiment is a modification of the first embodiment. The second embodiment will be described, focusing on the differences from the first embodiment.

[0063] The information code CD is used in both the distribution management system 110 and the traceability system 120. The distribution management system 110 and the traceability system 120 are management systems that manage a supply chain SC that is constructed to include a large number of traders TR. The supply chain SC is a connection between traders TR for delivering, for example, industrial products, agricultural products, and marine products to consumers. As an example, in the supply chain SC for delivering agricultural products to consumers shown in Figure 2, the traders TR include a farmer TR1, an agricultural cooperative TR2 that serves as a collection facility, a transporter TR3, and a retailer TR4.

[0064] The distribution management system 110 collects records of item transactions between traders TR using item codes, which are an example of public codes CP. In other words, the item codes are managed 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 label printer 12 and the code reader 13 are appropriately installed in the facilities of each trader TR. The input terminal 11, the label printer 12, and the code reader 13 are communicatively connected to the system server 10 installed in a data center or the like via a network.

[0065] The input terminal 11 is, for example, a personal computer or a tablet terminal. Basic information about items supplied to the supply chain SC (hereinafter referred to as item information) 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 about items shipped from the trader TR to the system server 10.

[0066] The label printer 12 is an output device for printing an information code CD containing an item code on a paper medium. The label printer 12 is configured to be capable of printing in color and grayscale. The paper medium on which the information code CD 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 item. In other words, the information code CD may be a printed matter that is displayed in a state where it is printed on a print medium.

[0067] The code reader 13 is a reader that acquires the public information recorded in the item code by reading the information code CD. The code reader 13 reads the item code when the information code CD is read without using the optical filter 23. The code reader 13 acquires the public information recorded in the item code and transmits the acquired public information to the system server 10.

[0068] 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 associated with the item information and generates an item code that records this public information. As part of the process of issuing an item code, the system server 10 transmits image data, etc., of the generated item code to the label printer 12, which is the sender of the item information. When the issued item code is circulated along with the item and read by the code reader 13 of another trader TR, the system server 10 accumulates a record of the item transaction by that trader TR.

[0069] 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.

[0070] The traceability system 120 collects transaction records using information codes CD based on item codes issued by the system server 10. The traceability system 120 is composed of a code output device 22, a history management server 20, etc. Furthermore, the traceability system 120 uses an input terminal 11, a label printer 12, a code reader 13, etc. of the distribution management system 110. The code output device 22, the code reader 13, and the input terminal 11 are connected via a network to the history management server 20, which is recorded in a data center or the like.

[0071] The code output device 22 is installed in the facility of the trader TR where the label printer 12 is installed. The code output device 22 is installed in such a way that it interrupts the communication line between the system server 10 and the label printer 12, and acquires item code data sent from the system server 10 to the label printer 12. The code output device 22 transmits the acquired item code data to the history management server 20.

[0072] The code output device 22 receives from the history management server 20 data for an information code CD that is generated based on the transmitted item code. The information code CD also stores tracking information as confidential information used in the traceability system 120. The code output device 22 transmits the data for the information code CD to the label printer 12 instead of the item code data. With the intervention of the code output device 22, the label printer 12 prints the information code CD on a paper medium without recognizing any modification (replacement) of the acquired code data. As a result, the code printing medium on which the information code CD is printed is affixed to the item instead of the item code, and is distributed together with the item.

[0073] 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 reader 13. The history management server 20 is primarily configured as a computer equipped with a processor 31, RAM 32, a storage unit 33, an input / output interface, and a bus connecting these. The processor 31 is hardware for arithmetic processing coupled to the RAM 32. The processor 31 includes at least one type of core, such as a central processing unit (CPU), a graphics processing unit (GPU), or a reduced instruction set computer (RISC)-CPU. The processor 31 accesses the RAM 32 to execute various processes related to data management. The storage unit 33 stores an information code generation program, which is one of the management programs related to data management, for causing the processor 31 to execute the code generation method according to the present disclosure.

[0074] In the traceability system 120, a single information code CD may be continuously used across multiple trader TRs, or a new information code CD may be issued for each trader TR. In a configuration in which a new information code CD 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 CD recording the new hash value as tracking information and provides the data of the new information code CD to the label printer 12 at the facility of the trader TR that conducted the transaction. As a result, the content is continually updated to reflect the transaction records up to that point. Furthermore, because the tracking information is primarily based on hash values, the amount of data in the tracking information can be maintained constant even as item transactions progress in the supply chain SC.

[0075] When the code reader 13 reads the information code CD through the optical filter 23, it reads out a tracking code, which is an example of the concealment code CH. The code reader 13 acquires the tracking information recorded in the tracking code and transmits the acquired tracking information to the history management server 20.

[0076] Whether the code reader 13 has used the optical filter 23 may be determined based on the state of a switch operated by the trader TR. Whether the code reader 13 has used the optical filter 23 may also be determined based on a brightness threshold LT set in a binarization process, for example. For example, if the brightness threshold LT is higher than a preset threshold, the code reader 13 may infer that the optical filter 23 is not being used, and information about this may be transmitted to the system server 10. If the brightness threshold LT is lower than a preset threshold, the code reader 13 may infer that the optical filter 23 is being used, and information about this may be transmitted to the history management server 20.

[0077] In the case where the optical filter unit 3 is attached to the code reader 13, the exposure state and filter application state of the optical filter unit 3 described in the first embodiment may be detected mechanically or electrically to determine whether the optical filter 23 has been used.

[0078] Furthermore, consumers of the final product can view the transaction records of the final product by using a traceability confirmation app installed on a user terminal 50, such as a smartphone or tablet terminal. Specifically, the user terminal 50 reads the code attached to the final product (which may be an information code CD or a separate additional code issued) and sends a transaction record reference request along with a hash value to the history management server 20, which is the point of contact for inquiries. Upon receiving the reference request, the history management server 20 extracts the item information and transaction record associated with the hash value and generates data to be provided. The history management server 20 then transmits the generated data to the user terminal 50, which is the source of the reference request. The consumer of the final product 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 records.

[0079] According to the second embodiment described above, the information code CD is a printed matter that is displayed in a state where it is printed on a print medium. The printed information code CD can be issued and distributed at low cost.

[0080] Furthermore, according to the second embodiment, the information code CD is attached to a trading item traded between traders and is distributed together with the trading item, thereby enabling appropriate management of the trading item.

[0081] (Other Embodiments) Although multiple embodiments have been described above, the present disclosure should not be construed as being limited to those embodiments, and can be applied to various embodiments and combinations within the scope that does not deviate from the gist of the present disclosure.

[0082] In other embodiments, the information code may be a code other than a QR code. For example, as shown in FIG. 18 , an information code CDb may be generated by a process of combining two barcodes CPb and CHb based on the combining rule of FIG. 4 . The information code CDb stores the two barcodes CPb and CHb superimposed in a common two-dimensional area. For example, as shown in FIG. 19 , an information code CDm may be generated by a process of combining two data matrices CPm and CHm based on the combining rule of FIG. 4 . The information code CDm stores the two data matrices CPm and CHm superimposed in a common two-dimensional area. Furthermore, the information code may store a plurality of different types of codes superimposed in a common two-dimensional area.

[0083] In other embodiments, when used in a retail store or restaurant as described in the first embodiment, the information code CD may be a printed matter that is displayed in a state where it is printed on a print medium. Also, when used in the traceability system 120 as described in the second embodiment, the information code CD may be an image display object that is displayed on an electronic display device.

[0084] In other embodiments, combinations of additional colors other than red and cyan may be used, such as green and magenta, blue and yellow, etc.

[0085] In other embodiments, the black cells BLC may be displayed using any first color similar to black that can be determined as black by binarization, such as dark gray. The white cells WHC may be displayed using any second color similar to white that can be determined as white by binarization, such as light gray. Even if the code generation device 1 is configured to display the cells as substantially black, the color of the cells displayed on the electronic display device may be within the above-mentioned first color range. Even if the code generation device 1 is configured to display the cells as substantially white, the color of the cells displayed on the electronic display device may be within the above-mentioned second color range.

[0086] In other embodiments, the functions provided by the code generation device 1, the history management server 20, the code readers 2, 13, etc. can be provided by software and hardware that executes the software, by software alone, by hardware alone, or a combination of these. When such functions are provided by electronic circuits as hardware, the functions can also be provided by digital circuits including multiple logic circuits, or by analog circuits.

[0087] For example, when the code reader 13 wants to read confidential information from the information code CD, it may capture a color image without using an optical film, and then restore the confidential code CH before synthesis by performing image processing on the color image by inversely calculating the synthesis rule of Figure 4.

[0088] 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.

[0089] (Disclosure of Technical Ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be described in a multiple dependent form, where the subsequent clause alternatively cites the preceding clause. These multiple dependent clauses define multiple technical ideas.

[0090] (Technical Idea 1) An information code decoded according to brightness recognized by a reader (2, 13), wherein a first code (CP, CPb, CPm) indicating first information and a second code (CH, CHb, CHm) indicating second information are recorded in a common two-dimensional area by arranging cells (WHC, BLC, RDC, CYC) encoding at least a first symbol or a second symbol with the first code and the second code, respectively, in such a manner that they are superimposed on each other; a cell (BLC) in which the first symbol is encoded with the first code and the first symbol is encoded with the second code is displayed in a first color that becomes black through binarization; and a cell (WHC) in which the second symbol is encoded with the first code and the second symbol is encoded with the second code is displayed in a second color that becomes white through binarization; An information code comprising: a cell (RDC) in which the first symbol is coded by the first code and the second symbol is coded by the second code, displayed in a first auxiliary color; and a cell (CYC) in which the second symbol is coded by the first code and the first symbol is coded by the second code, displayed in a second auxiliary color that is recognized by the reader under white light with a higher brightness than when displayed in the first auxiliary color, and that is recognized by the reader under light of the first auxiliary color with a lower brightness than when displayed in the first auxiliary color.

[0091] (Technical Idea 2) An information code according to Technical Idea 1, wherein the first auxiliary color is one of the three primary colors of light, and the second auxiliary color is an additive mixture of the remaining two primary colors of the three primary colors of light.

[0092] (Technical Concept 3) The information code according to Technical Concept 2, wherein the first auxiliary color is red, and the second auxiliary color is cyan.

[0093] (Technical Concept 4) The information code according to any one of Technical Concepts 1 to 3, which is an image display object displayed on an electronic display device (1d).

[0094] (Technical Concept 5) The information code according to any one of Technical Concepts 1 to 3, which is a printed matter that is displayed in a printed state on a print medium.

[0095] (Technical Idea 6) An information code according to any one of Technical Ideas 1 to 5, which is attached to a trading item traded between traders and is configured to be circulated together with the trading item.

[0096] (Technical Idea 7) An information code configured to be readable by a reader (2, 13) by performing a binarization process on brightness, wherein a public code (CP, CPb, CPm) representing public information is arranged by arranging a plurality of cells (WHC, BLC, RDC, CYC) in which either a first symbol or a second symbol that can be distinguished by the binarization process is embedded, and a concealment code (CH, CHb, CHm) representing concealed information is arranged by arranging a plurality of cells in which either the first symbol or the second symbol is embedded, and these are superimposed and recorded in a common two-dimensional area, a cell (BLC) in which the first symbol is embedded by the public code and the first symbol is embedded by the concealment code is displayed in black, and a cell (WHC) in which the second symbol is embedded by the public code and the second symbol is embedded by the concealment code is displayed in white, An information code, comprising: a cell (RDC) into which the first symbol is embedded in the disclosure code and the second symbol is embedded in the confidentiality code, displayed in a first auxiliary color; and a cell (CYC) into which the second symbol is embedded in the disclosure code and the first symbol is embedded in the confidentiality code, displayed in a second auxiliary color that is recognized by the reader under white light with a higher brightness than when displayed in the first auxiliary color, and that is recognized by the reader under light of the first auxiliary color with a lower brightness than when displayed in the first auxiliary color.

Claims

1. An information code decoded according to the brightness recognized by a reader (2, 13), comprising: a first code (CP, CPb, CPm) indicating first information and a second code (CH, CHb, CHm) indicating second information, which are superimposed and recorded in a common two-dimensional area by arranging cells (WHC, BLC, RDC, CYC) encoding at least a first symbol or a second symbol with the first code and the second code, respectively; a cell (BLC) in which the first symbol is encoded with the first code and the first symbol is encoded with the second code is displayed in a first color that becomes black through binarization processing; a cell (WHC) in which the second symbol is encoded with the first code and the second symbol is encoded with the second code is displayed in a second color that becomes white through binarization processing; and a cell (RDC) in which the first symbol is encoded with the first code and the second symbol is encoded with the second code is displayed in a first auxiliary color. An information code, wherein the second symbol is encoded in the first code, and a cell (CYC) in which the first symbol is encoded in the second code is displayed in a second supplementary color that is recognized by the reader with a higher brightness under white light than the display in the first supplementary color, and that is recognized by the reader with a lower brightness under light of the first supplementary color than the display in the first supplementary color.

2. The information code according to claim 1, wherein the first supplementary color is one of the three primary colors of light, and the second supplementary color is an additive mixture of the remaining two primary colors of the three primary colors of light.

3. The information code according to claim 2, wherein the first auxiliary color is red and the second auxiliary color is cyan.

4. An information code according to any one of claims 1 to 3, which is an image display object displayed on an electronic display device (1d).

5. The information code according to any one of claims 1 to 3, which is a printed matter displayed in a printed state on a print medium.

6. The information code according to claim 1, which is configured to be attached to a trading item traded between traders and to be distributed together with said trading item.

7. An information code generating device comprising at least one processor (1a, 31) and configured to generate an information code that is readable by a reader (2, 13) by executing a binarization process on luminance, wherein the at least one processor generates the information code in which a public code (CP, CPb, CPm) representing public information and a confidentiality code (CH, CHb, CHm) representing confidential information are superimposed and recorded in a common two-dimensional area by arranging a plurality of cells (WHC, BLC, RDC, CYC) in which either a first symbol or a second symbol that can be distinguished by the binarization process is embedded, and a confidentiality code (CH, CHb, CHm) representing confidential information are superimposed and recorded in a common two-dimensional area by arranging a plurality of cells in which either the first symbol or the second symbol is embedded, and wherein the at least one processor, in generating the information code, sets a cell (BLC) in which the first symbol is embedded in the public code and in which the first symbol is embedded in the confidentiality code to be displayed in black, An information code generating device which sets a cell (WHC) in which the second symbol is embedded in the public code and the second symbol is embedded in the secret code to be displayed in white, sets a cell (RDC) in which the first symbol is embedded in the public code and the second symbol is embedded in the secret code to be displayed in a first supplementary color, and sets a cell (CYC) in which the second symbol is embedded in the public code and the first symbol is embedded in the secret code to be displayed in a second supplementary color which is recognized by the reader at a higher brightness under white light than the display in the first supplementary color and which is recognized by the reader at a lower brightness under light of the first supplementary color than the display in the first supplementary color.

8. An information code generation program for generating an information code configured to be readable by a reader (2, 13) by performing a binarization process on luminance, the program being configured to cause at least one processor (1a, 31) to execute the following steps: generate the information code in which a public code (CP, CPb, CPm) representing public information is superimposed and recorded in a common two-dimensional area by arranging a plurality of cells (WHC, BLC, RDC, CYC) in which either a first symbol or a second symbol that can be distinguished by the binarization process is embedded, and a concealment code (CH, CHb, CHm) representing concealment information is superimposed and recorded in a common two-dimensional area by arranging a plurality of cells in which either the first symbol or the second symbol is embedded; and in generating the information code, set a cell (BLC) in which the first symbol is embedded in the public code and in which the first symbol is embedded in the concealment code to be displayed in black, an information code generating program configured to set a cell (WHC) in which the second symbol is embedded in the public code and the second symbol is embedded in the secret code to be displayed in white; set a cell (RDC) in which the first symbol is embedded in the public code and the second symbol is embedded in the secret code to be displayed in a first auxiliary color; and set a cell (CYC) in which the second symbol is embedded in the public code and the first symbol is embedded in the secret code to be displayed in a second auxiliary color that is recognized by the reader at a higher brightness under white light than the display in the first auxiliary color and that is recognized by the reader at a lower brightness under light of the first auxiliary color than the display in the first auxiliary color.

Images