Printed matter, composite two-dimensional symbol, composite display method for two-dimensional symbol, image data generation method, and reading method for composite two-dimensional symbol

Abstract

Provided is printed matter in which two two-dimensional symbols can be displayed integrally while readability of each of the symbols is maintained. In the printed matter that has provided thereon a first two-dimensional symbol 2 and a second two-dimensional symbol 3 that are formed by vertically and horizontally arranging bright color cells and dark color cells, the first two-dimensional symbol 2 and the second two-dimensional symbol 3 are arranged such that finder patterns 23, 34, 35 do not overlap one another and coding areas 22, 32 partially overlap each other. Then, the cells of the first two-dimensional symbol 2 and the second two-dimensional symbol 3 are arranged in a common array orientation and at a common array pitch such that the central parts of the cells do not overlap one another, and in a portion where the coding areas 22, 32 overlap each other, the central parts of the cells are colored in color arrangement patterns of the cells, respectively.

Description

Printed matter, synthetic two-dimensional symbol, method for synthetic display of two-dimensional symbol, method for generating image data, and method for reading synthetic two-dimensional symbol

[0001] The present invention relates to a technique for overlapping a plurality of two-dimensional symbols and displaying them on printed matter or the like.

[0002] Two-dimensional symbols such as QR codes (registered trademarks) and data matrices have an error correction function and can be read even if they are partially damaged. Therefore, within a range where there is no hindrance to reading the two-dimensional symbol, an arbitrary design image is overlapped and displayed on the two-dimensional symbol (for example, Patent Document 1).

[0003] On guidance stickers and pamphlets, QR codes recording the URLs of web pages for checking detailed information may be displayed side by side for each content. Also, QR codes recording the URLs of Japanese pages and English pages regarding the same content may be displayed side by side.

[0004] In addition, on product packages, product identification codes (GS1 identification codes) recording product identification information are displayed. Also, on many product packages, apart from the product identification code, a QR code recording the URL of a website is displayed, and consumers and the like can check product information by accessing the website. Currently, most product identification codes are one-dimensional symbols, but in recent years, in place of one-dimensional symbols with a small storage capacity, efforts have been made to use two-dimensional symbols (data matrices) to represent not only product identification information but also attribute information such as expiration dates and lot numbers.

[0005] JP-A-2007-034998, Figure 2

[0006] As described above, if a plurality of QR codes are displayed, the convenience is enhanced because one can directly access the desired information simply by selecting the QR code to be read, but it is necessary to secure a wide display area for the QR codes.

[0007] Furthermore, since both QR codes and data matrices are matrix-type symbols, if both are displayed on the product packaging, unfamiliar customers may not be able to instantly determine which one to scan when using a self-checkout scanner, potentially causing delays in the payment process.

[0008] To address this problem, it is proposed to arrange two two-dimensional symbols on top of each other to make the display space more compact and to make it easier to hold both two-dimensional symbols over the scanner simultaneously. As shown in Figure 18(A), even if one two-dimensional symbol 3 overlaps one two-dimensional symbol 2 to some extent and a part of it is missing, the error correction function of two-dimensional symbol 2 can compensate for the missing part, so both two-dimensional symbols 2 and 3 can be read without any problems. However, as shown in Figure 18(B), if two-dimensional symbols 2 and 3 are significantly overlapped, at least one of the two-dimensional symbols 2 will have a level of loss that cannot be corrected and will become unreadable, making it impossible to maintain the readability of both two-dimensional symbols 2 and 3.

[0009] This invention has been made in view of the current situation and aims to provide printed materials, etc., that can display two two-dimensional symbols on a large, superimposed scale while maintaining the readability of each symbol.

[0010] The present invention relates to a printed material having a first two-dimensional symbol and a second two-dimensional symbol arranged thereon, wherein the first two-dimensional symbol and the second two-dimensional symbol are matrix-type symbols formed by arranging light and dark colored cells vertically and horizontally, each comprising a finder pattern for detecting the position of the symbol and an encoding area for recording data, wherein the finder patterns of the first two-dimensional symbol and the second two-dimensional symbol are arranged so as not to overlap with each other, the encoding areas of the first two-dimensional symbol and the second two-dimensional symbol each have an error correction function and are arranged so that parts of them overlap with each other, the cells of the first two-dimensional symbol and the second two-dimensional symbol are arranged with a common arrangement direction and arrangement pitch, so that their respective centers do not overlap, and in the parts where their respective encoding areas overlap, the centers of each cell are colored according to the respective cell's color scheme pattern.

[0011] In a typical matrix-type two-dimensional symbol, the cells are rectangular in shape with sides equal to the array pitch (hereinafter referred to as "normal size") and are arranged without gaps vertically and horizontally. However, since the color identification of cells in the coding region is determined based on the color of the center, even if the cells in the coding region are displayed smaller than the normal size, readability is not significantly impaired as long as the center (near the center coordinates calculated from the finder pattern) is correctly colored. For this reason, by arranging the cells of two two-dimensional symbols so that their centers do not overlap in the overlapping coding regions, and by displaying each cell smaller than the normal size, the cells can be arranged without overlapping. In such a configuration, the lightness and darkness of the cells of each two-dimensional symbol can be accurately identified in the overlapping coding regions of the two two-dimensional symbols. The two-dimensional symbol reading program identifies the center coordinates of each cell in the coding region based on the finder pattern, etc., and identifies whether each cell is light or dark based on the color of the pixel in the center of each cell. Therefore, according to the present invention, two two-dimensional symbols can be displayed as a single unit by significantly overlapping them.

[0012] In the present invention, it is proposed that the center of the cell of the first two-dimensional symbol and the center of the cell of the second two-dimensional symbol are offset by half the arrangement pitch of each cell in both the vertical and horizontal arrangement directions.

[0013] In this configuration, the center of the cell of the first two-dimensional symbol and the center of the cell of the second two-dimensional symbol can be separated as far apart as possible in the overlapping coding areas, thereby minimizing the mixing of colors between the cells of the first and second two-dimensional symbols due to camera shake during imaging.

[0014] Furthermore, in the above configuration, it is proposed that in the portion where the encoding areas of the first two-dimensional symbol and the second two-dimensional symbol overlap, the cells of the first two-dimensional symbol and the second two-dimensional symbol form a rhombus of equal area and are arranged adjacent to each other without gaps.

[0015] In this configuration, the area of ​​each cell can be maximized without variation in the overlapping coding regions, thus minimizing the risk of errors in cell color identification due to camera shake during imaging.

[0016] Furthermore, in the present invention, the first two-dimensional symbol is a rectangular two-dimensional symbol having finder patterns at three corners, and the second two-dimensional symbol is a rectangular two-dimensional symbol having the same finder patterns at three corners as the first two-dimensional symbol. The first and second two-dimensional symbols are arranged such that the corners without finder patterns overlap each other, and all finder patterns do not overlap each other, by rotating the other two-dimensional symbol by 180° relative to the other two-dimensional symbol. In particular, in this configuration, the first and second two-dimensional symbols are proposed to be QR codes.

[0017] When displaying overlapping rectangular two-dimensional symbols, such as QR codes, which have finder patterns at three corners, by overlapping the first and second two-dimensional symbols rotated 180° in the configuration shown, it is possible to overlap a large portion of the symbols other than the finder patterns without overlapping their respective finder patterns.

[0018] Furthermore, in the above configuration, the first two-dimensional symbol and the second two-dimensional symbol are provided with a data code area in which a data code word for recording data and an error correction code word for correcting errors in the data code word are recorded, and the data code area is provided with an area in the remaining area after the data code word and the error correction code word have been recorded in which identification information that allows the first two-dimensional symbol and the second two-dimensional symbol to distinguish each other is recorded.

[0019] If the shape of the finder pattern is identical for the first two-dimensional symbol and the second two-dimensional symbol, it is not possible to distinguish which two-dimensional symbol's data to read based on the detected finder pattern. However, in this configuration, the reading program can identify whether the data read by the reading program is recorded on the first or second two-dimensional symbol based on the identification information recorded on each two-dimensional symbol, thus having the advantage of making the processing of data read from the two-dimensional symbols less time-consuming. Furthermore, since the identification information recorded in the remaining area of ​​the data code region is not read by general QR code reading programs, this identification information does not hinder the reading by general-purpose reading programs.

[0020] Furthermore, a configuration has also been proposed in which the first two-dimensional symbol and the second two-dimensional symbol each include a data code area in which a data code word for recording data and an error correction code word for correcting errors in the data code word are recorded, and the data code area further includes an area in the remaining area after the data code word and the error correction code word have been recorded for recording attribute information indicating the attributes of the data recorded by the data code word.

[0021] If the shape of the finder pattern is identical for the first two-dimensional symbol and the second two-dimensional symbol, the attributes of the data recorded in the two-dimensional symbol cannot be identified based on the detected finder pattern. However, in this configuration, the attributes of the data read by the reading program can be easily identified based on the attribute information of the data recorded in each two-dimensional symbol, which has the advantage of making it easier to process the data read from the two-dimensional symbol. In addition, the attribute information recorded in the remaining area of ​​the data code area cannot be read by a general QR code reading program, so this attribute information does not hinder reading by a general-purpose reading program. Examples of data attributes indicated by attribute information include web addresses, product identification information, digital signatures, encrypted data, facial feature vectors, and error correction data.

[0022] Furthermore, in the present invention, the finder patterns of the first two-dimensional symbol and the second two-dimensional symbol are composed of rectangular cells whose side length is equal to the cell arrangement pitch, and in the overlapping portion of the finder pattern of one two-dimensional symbol and the encoding area of ​​the other two-dimensional symbol, the color scheme pattern of the cells of the other two-dimensional symbol is missing.

[0023] As mentioned above, the readability of the encoded area cells is not significantly impaired even when displayed smaller than the normal size. However, when the finder pattern cells are displayed smaller than the normal size, it becomes difficult to detect the two-dimensional symbols. On the other hand, even if some cells in the encoded area are missing, this can be compensated for by the error correction function.

[0024] In the present invention, the first two-dimensional symbol is a rectangular two-dimensional symbol having finder patterns at three corners, with the corner without a finder pattern overlapping with the second two-dimensional symbol, and all finder patterns being arranged so as not to overlap with the second two-dimensional symbol. The second two-dimensional symbol is a rectangular two-dimensional symbol having finder patterns on all four sides, with the finder patterns on two sides overlapping with the first two-dimensional symbol, and the finder patterns on the remaining two sides not overlapping with the first two-dimensional symbol.

[0025] As another aspect of the present invention, a composite two-dimensional symbol is proposed, comprising a first two-dimensional symbol and a second two-dimensional symbol arranged in a superimposed manner, wherein the first two-dimensional symbol and the second two-dimensional symbol are matrix-type symbols formed by arranging light and dark colored cells vertically and horizontally, each comprising a finder pattern for detecting the position of the symbol and an encoding area for recording data, wherein the finder patterns of the first two-dimensional symbol and the second two-dimensional symbol are arranged so as not to overlap with each other, the encoding areas of the first two-dimensional symbol and the second two-dimensional symbol each have an error correction function and are arranged so that parts of them overlap with each other, the cells of the first two-dimensional symbol and the second two-dimensional symbol are arranged with a common arrangement direction and pitch, so that their respective centers do not overlap, and in the parts where their respective encoding areas overlap, the centers of each cell are colored according to the respective cell's color scheme pattern. Such a composite two-dimensional symbol may be printed on printed material or displayed on a screen.

[0026] Furthermore, in the above-mentioned composite two-dimensional symbol, the first two-dimensional symbol is a rectangular QR code having finder patterns at three corners, and the second two-dimensional symbol is a rectangular QR code having finder patterns of the same size as the first two-dimensional symbol at three corners. The first and second two-dimensional symbols are arranged such that the other two-dimensional symbol is rotated 180° relative to the other two-dimensional symbol, so that the corners without finder patterns overlap, and all of the finder patterns do not overlap.

[0027] If the first and second two-dimensional symbols are composed of rectangular two-dimensional symbols with finder patterns at three corners, such as a QR code, then by overlapping the first and second two-dimensional symbols in opposite directions by 180°, as in this configuration, it is possible to overlap a large portion of the parts other than the finder patterns without overlapping the respective finder patterns.

[0028] Furthermore, in another aspect of the present invention, a composite display method for two-dimensional symbols is proposed, wherein the first two-dimensional symbol and the second two-dimensional symbol are superimposed, and the first two-dimensional symbol and the second two-dimensional symbol are matrix-type symbols formed by arranging light and dark colored cells vertically and horizontally, each comprising a finder pattern for detecting the position of the symbol and an encoding area for recording data, each encoding area being equipped with an error correction function, the finder patterns of the first two-dimensional symbol and the second two-dimensional symbol are displayed so as not to overlap with each other, the encoding areas of the first two-dimensional symbol and the second two-dimensional symbol are displayed so as to partially overlap with each other, the cells of the first two-dimensional symbol and the second two-dimensional symbol are arranged with a common arrangement direction and pitch so as not to overlap their respective centers, and in the parts where their respective encoding areas overlap, the centers of each cell are displayed with the respective cell's color scheme pattern. Such composite display methods include both printing two-dimensional symbols on printed materials and displaying two-dimensional symbols on a display.

[0029] The present invention provides an image data generation method for generating image data of a composite two-dimensional symbol, comprising a first step in which a computer generates data indicating the color scheme of the composite two-dimensional symbol based on data indicating the color scheme of the cells of the first two-dimensional symbol and data indicating the color scheme of the cells of the second two-dimensional symbol, wherein the first step determines which regions of the first two-dimensional symbol and which regions of the second two-dimensional symbol will be superimposed based on the number of cells of the first two-dimensional symbol and the number of cells of the second two-dimensional symbol.

[0030] In this image data generation method, it is generally desirable to pre-determine patterns for overlapping two two-dimensional symbols for each combination of the number of cells in the two two-dimensional symbols. The image data of the composite two-dimensional symbol may be in raster format, or it may be data that shows the color scheme pattern of the cells of the composite two-dimensional symbol.

[0031] In the above-described image data generation method, the composite two-dimensional symbol is arranged such that at least a portion of the finder pattern of the second two-dimensional symbol overlaps with the encoding region of the first two-dimensional symbol, and the color scheme pattern of the cells of the first two-dimensional symbol is missing in the overlapping portion of the finder pattern of the second two-dimensional symbol and the encoding region of the first two-dimensional symbol. The method comprises a second step in which, before the first step, the computer generates data indicating the color scheme pattern of the cells of the first two-dimensional symbol based on data recorded in the first two-dimensional symbol, and a third step in which, before the second step, the computer generates data indicating the color scheme pattern of the cells of the second two-dimensional symbol based on data recorded in the second two-dimensional symbol, wherein in the second step, the number of cells of the first two-dimensional symbol is determined in accordance with the number of cells of the second two-dimensional symbol.

[0032] As described above, when the finder pattern of the second two-dimensional symbol is superimposed on the first two-dimensional symbol, causing some cells of the first two-dimensional symbol to be missing, the number of missing cells in the first two-dimensional symbol tends to increase as the number (size) of cells in the second two-dimensional symbol increases. Therefore, it is desirable to determine the number of cells in the first two-dimensional symbol in accordance with the number of cells in the second two-dimensional symbol, as in the method described above, so that the color scheme of the missing cells can be adequately compensated for.

[0033] A method for reading a composite two-dimensional symbol according to the present invention is proposed, comprising: a first step in which a computer acquires an image of the composite two-dimensional symbol captured by an imaging device; a second step in which the computer decodes the recording information of the first two-dimensional symbol based on the image; a third step in which the computer decodes the recording information of the second two-dimensional symbol based on the image; and a fourth step in which the computer combines the decoded recording information of the two two-dimensional symbols to generate new information.

[0034] The composite two-dimensional symbol according to the present invention is basically configured so that superimposed two-dimensional symbols are selectively read by the reading programs for each two-dimensional symbol. However, as described above, the usefulness of the two two-dimensional symbols can be improved by reading the recorded information of both two two-dimensional symbols and combining the individual recorded information.

[0035] A specific example of the method for reading the above-mentioned composite two-dimensional symbol is that the recorded information of the first two-dimensional symbol is a web address providing product information, the recorded information of the second two-dimensional symbol is the product identification information, and the new information is a URL that includes a subdirectory and / or URL parameters generated from part or all of the product identification information in addition to the web address.

[0036] A method for reading a composite two-dimensional symbol in which a first two-dimensional symbol and a second two-dimensional symbol are QR codes is proposed, comprising: an imaging step in which a computer acquires an image of the composite two-dimensional symbol captured by an imaging device; a first decoding step in which the computer searches for finder patterns of the first two-dimensional symbol and the second two-dimensional symbol included in the image and decodes the recorded information of the two-dimensional symbol relating to the previously detected finder pattern; an image modification step in which the computer generates a modified image of the image in which the finder pattern previously detected in the second step has been modified to a manner that makes it difficult to detect; and a second decoding step in which the computer searches for unmodified finder patterns included in the modified image and decodes the recorded information of the two-dimensional symbol relating to the detected finder pattern.

[0037] According to this reading method, the finder pattern of the two-dimensional symbol decoded in the first decoding step is not detected in the second decoding step, so the finder pattern of the remaining second two-dimensional symbol can be detected quickly and reliably.

[0038] Furthermore, in the method for reading the composite two-dimensional symbol described above, it is proposed to configure the system to enable the execution of a process to determine the position of the center of the cell of the other two-dimensional symbol based on the finder pattern of one of the two-dimensional symbols, or the finder patterns of both of the two-dimensional symbols.

[0039] In the composite two-dimensional symbol according to the present invention, the displacement between the cells of one two-dimensional symbol and the cells of the other two-dimensional symbol is constant. Therefore, the position of the center of the cells of the other two-dimensional symbol can sometimes be determined based on the finder pattern of the one two-dimensional symbol. For this reason, as in the reading method described above, if the process of determining the position of the center of the other two-dimensional symbol is performed based on the finder pattern of one two-dimensional symbol, the other two-dimensional symbol can be read even if the detection of the finder pattern of the other two-dimensional symbol fails. Furthermore, if the position of the center of the cells of the other two-dimensional symbol is determined based on the finder patterns of both two-dimensional symbols, the position of the center of the cells can be identified more accurately.

[0040] As described above, the present invention makes it possible to display two two-dimensional symbols integrally on printed materials, etc., while maintaining the readability of each. Furthermore, by displaying two-dimensional symbols with different finder patterns, such as QR codes and data matrices, integrally as a composite two-dimensional symbol using the present invention, there is no hesitation in deciding which part to point the scanner or camera at when reading a QR code or a data matrix. Moreover, since the composite two-dimensional symbol, which is a superimposed QR code and a data matrix, can be processed by existing data matrix reading programs to read the recorded information of the data matrix, and processed by existing QR code reading programs to read the recorded information of the QR code, no dedicated programs are required for reading the recorded information of the two two-dimensional symbols individually.

[0041] This is an explanatory diagram showing the composite two-dimensional symbol 1 of Example 1. (A) is the QR code 2 that constitutes the composite two-dimensional symbol 1. (B) is an explanatory diagram showing the QR code 2 divided into functional areas. (A) is the data matrix 3 that constitutes the composite two-dimensional symbol 1. (B) is an explanatory diagram showing the QR code 3 divided into functional areas. (A) is the composite two-dimensional symbol 1, and (B) is an explanatory diagram showing the QR code 20 and the QR code 30 of the data matrix 3 that constitute the composite two-dimensional symbol 1 separated. This is an explanatory diagram showing the cells 20 of the QR code 2 (A) and the cells 30 of the data matrix 3 (B) that constitute the composite two-dimensional symbol 1 separately. (A) and (B) show the arrangement of the QR code 2 and the normal-sized cells 20 and 30 of the data matrix 3, (C) and (D) show the arrangement of the QR code 2 and the reduced-sized cells 20 and 30 of the data matrix 3, and (E) shows the arrangement of the reduced-sized cells 20 and 30 of the two two-dimensional symbols 2 and 3 placed in the overlapping area 11. This is an example of a product package C printed with the composite two-dimensional symbol 1. This is a flowchart showing the processing procedure of a dedicated reading program for the composite two-dimensional symbol 1. This is an explanatory diagram showing an example of using the composite two-dimensional symbol 1 according to the reading program. This is a flowchart showing the processing procedure of the generation program for the composite two-dimensional symbol 1. This is an explanatory diagram showing the composite two-dimensional symbol 1a of Example 2. (A) is the Aztec code 4 that constitutes the composite two-dimensional symbol 1a. (B) is an explanatory diagram showing the different patterns of each area of ​​the Aztec code 4 according to its function. (A) is the composite two-dimensional symbol 1a. (B) is an explanatory diagram showing the different patterns of each area of ​​the composite two-dimensional symbol 1a. This is an explanatory diagram showing the composite two-dimensional symbol 1b of Example 3. This is an explanatory diagram showing an example of using the two-dimensional symbol 1b of Example 3. This is a flowchart showing the processing procedure of the dedicated reading program for the composite two-dimensional symbol 1b of Example 3. This is an explanatory diagram showing the arrangement of cells 20 and 30 in a modified example. This is an explanatory diagram showing a reference example of simply superimposing two two-dimensional symbols 2 and 3.

[0042] Embodiments of the present invention will be described according to the following examples. In the following examples, the first two-dimensional symbol according to the present invention corresponds to QR codes 2, 2a, and 2b, and the second two-dimensional symbol according to the present invention corresponds to the data matrix 3, Aztec code 4, and QR code 2c. Furthermore, the printed material according to the present invention corresponds to product package C.

[0043] As shown in Figure 1, the composite two-dimensional symbol 1 according to this embodiment is formed by superimposing two two-dimensional symbols 2 and 3 and displaying them as a single unit. Both two two-dimensional symbols 2 and 3 are matrix-type symbols consisting of light and dark colored cells arranged vertically and horizontally, but the specifications of the two two-dimensional symbols 2 and 3 are different. Specifically, one two-dimensional symbol 2 is a QR code, and the other two-dimensional symbol 3 is a data matrix. In the composite two-dimensional symbol 1, the two two-dimensional symbols 2 and 3 overlap over a wide area, but the readability of each two-dimensional symbol 2 and 3 is maintained. That is, if the image of the composite two-dimensional symbol 1 is processed with a general QR code reading program, the information recorded in the QR code 2 is decoded. Also, if the image of the composite two-dimensional symbol 1 is processed with a general data matrix reading program, the information recorded in the data matrix 3 is decoded. Before describing the configuration of the composite two-dimensional symbol 1, the configurations of the two superimposed two-dimensional symbols 2 and 3 will be described below.

[0044] As shown in FIG. 2(A), the QR code 2 is formed by arranging 29 square cells 20 each in a matrix pattern at a constant pitch vertically and horizontally. Each cell 20 is colored either light (white) or dark (black). As shown in FIG. 2(B), the QR code 2 is roughly divided into two regions: a function pattern 21 and an encoding region 22. The function pattern 21 is a region for assisting the optical reading of the QR code 2. The encoding region 22 is a region for recording data according to the color pattern of the cells 20. The color pattern of the cells 20 in the function pattern 21 is determined regardless of the data to be recorded, and the color pattern of the cells 20 in the encoding region 22 varies according to the data to be recorded. In FIG. 2(B), the region where the cells 20 are represented by white or black corresponds to the function pattern 21, and the region where the cells 20 are shown shaded corresponds to the encoding region 22.

[0045] The function pattern 21 of the QR code 2 is composed of a finder pattern 23, a separation pattern 24, a timing pattern 25, and an alignment pattern 26. The finder pattern 23 is a concentric square pattern provided at three corners of the symbol. With such a pattern, the symbol can be easily detected from the image of the QR code 2 captured. The separation pattern 24 is a pattern of light-colored cells 20 surrounding the finder pattern 23, and with such a pattern, the finder pattern 23 can be separated and identified from the surroundings. The timing pattern 25 is a pattern in which light and dark cells 20 appear alternately in a single row in the vertical and horizontal directions. With such a pattern, it becomes easy to specify the center coordinates of each cell 20 in the image of the QR code 2 captured. The alignment pattern 26 is a concentric square pattern provided at the lower right of the symbol. With such a pattern, it becomes easy to correct the distortion of the symbol in the image of the QR code 2 captured.

[0046] The encoding area 22 of QR code 2 consists of a data code area 27 and a format information code area 28. The data code area 27 is provided with codewords, each consisting of 8 bits. The codewords consist of data codewords for recording data, error correction codewords for correcting errors in the data codewords, and filler codewords to fill the remaining area of ​​the data code area 27. The format information code area 28 records the format information and model number information of QR code 2. The format information includes the error correction level of QR code 2. Because the encoding area 22 has an error correction function built in, even if the brightness of cell 20 is misidentified due to soiling of the printed material or camera shake during imaging when reading QR code 2, the recorded data can be read correctly as long as the error is below a predetermined percentage. Note that these configurations conform to the QR code standard (JIS X 0510:2018 or ISO / IEC 18004:2015), so a detailed explanation is omitted.

[0047] As shown in Figure 3(A), the data matrix 3 consists of square cells 30 arranged in a matrix pattern with 20 cells vertically and 20 horizontally at a constant pitch, and each cell 30 is colored either light (white) or dark (black). As shown in Figure 3(B), the data matrix 3 is broadly divided into two areas: a functional pattern 31 and an encoding area 32. The functional pattern 31 is an area for assisting the optical reading of the data matrix 3. The encoding area 32 is an area for recording data based on the color scheme of the cells 30. The color scheme of the cells 30 in the functional pattern 31 is determined independently of the data to be recorded, while the color scheme of the cells 30 in the encoding area 32 varies depending on the data to be recorded. In Figure 3(B), the area where the cells 30 are represented in white or black corresponds to the functional pattern 31, and the area where the cells 30 are displayed in shaded areas corresponds to the encoding area 32.

[0048] As shown in FIG. 3(B), in the data matrix 3, the functional pattern 31 is arranged with a width of 1 cell along the outer peripheral edge of the symbol, and the encoding region 32 is provided inside the functional pattern 31. The functional pattern 31 consists of an L-shaped pattern 34 arranged on two adjacent sides of the outer peripheral edge and a clock pattern 35 arranged on the remaining two sides of the outer peripheral edge. All the cells 30 of the L-shaped pattern 34 are colored dark, and the cells 30 of the clock pattern 35 are alternately colored light and dark. The data matrix reading program can detect the position of the data matrix 3 in the image and identify the size and cell structure of the symbol by using the L-shaped pattern 34 and the clock pattern 35 as clues. That is, such an L-shaped pattern 34 and clock pattern 35 correspond to the finder pattern of the data matrix 3.

[0049] In the encoding region 32 of the data matrix 3, a code word with 8 bits per word is provided. The code word consists of a data code word for recording data, an error correction code word for correcting errors in the data code word, and a padding code word for filling the remaining area. Since an error correction function is incorporated in the encoding region 32, when reading the data matrix 3, even if the identification of the light and dark of the cells 30 is incorrect due to dirt on the printed matter or camera shake during imaging, as long as the error is below a predetermined ratio, the recorded data can be correctly read. Since these configurations conform to the standard (ECC200) of the data matrix 3, detailed explanations are omitted.

[0050] The composite two-dimensional symbol 1 is formed by overlapping and integrally displaying the QR code 2 in FIG. 2(A) and the data matrix 3 in FIG. 3(A). As shown in FIG. 4, the composite two-dimensional symbol 1 is composed of single regions 10a and 10b where the QR code 2 and the data matrix 3 do not overlap and an overlapping region 11 where the QR code 2 and the data matrix 3 overlap.

[0051] In the composite two-dimensional symbol 1, the central to lower right portion of the QR code 2 is included in the overlapping region 11. Specifically, a portion of the encoded region 22 of the QR code 2 and the entire alignment pattern 26 are included in the overlapping region 11. The remaining portion of the encoded region 22 of the QR code 2, along with the entire finder pattern 23, separation pattern 24, and timing pattern 25, are included in the single region 10a.

[0052] On the other hand, the data matrix 3 is almost entirely contained within the overlapping region 11. Specifically, the coding region 32 and the clock pattern 35 are contained within the overlapping region 11, while the L-shaped pattern 34 is contained within the independent region 10b. The data matrix 3 is rotated 90° relative to the QR code 2 so that the entire L-shaped pattern 34 is contained within the independent region 10b. This is because the L-shaped pattern 34 is more important than the clock pattern 35 for position detection of the data matrix 3.

[0053] In the composite two-dimensional symbol 1, two two-dimensional symbols 2 and 3 are superimposed with the arrangement direction and arrangement pitch of cells 20 and 30 aligned. As mentioned above, in this embodiment, the data matrix 3 is rotated 90° so that the vertical direction of the QR code 2 and the horizontal direction of the data matrix 3 are aligned. In this way, if the arrangement pitch of cells 20 and 30 is the same in both the vertical and horizontal directions, the two-dimensional symbols may be superimposed so that the vertical direction of one two-dimensional symbol 2 is aligned with the horizontal direction of the other two-dimensional symbol 3.

[0054] Furthermore, in the composite two-dimensional symbol 1, the QR code 2 and the data matrix 3 are arranged so that the centers of their respective cells 20 and 30 do not overlap. Specifically, the centers of cell 20 of the QR code 2 and cell 30 of the data matrix 3 are offset by half the arrangement pitch of cells 20 and 30 in the vertical and horizontal directions, respectively.

[0055] In this way, by arranging the cells 20 and 30 of the two two-dimensional symbols 2 and 3 with a common array direction and array pitch, and offsetting them so that the centers of each cell 20 and 30 do not overlap, as shown in Figure 5, the cells 20 and 30 included in the overlapping region 11 can be displayed in a reduced size, allowing the area around the center of each cell 20 and 30 to be colored according to the respective color scheme of the cells 20 and 30.

[0056] Specifically, as shown in Figures 6(A) and 6(B), the standard-sized cells 20 and 30 of the QR code 2 and data matrix 3 form a square shape with a side length equal to the arrangement pitch P of the cells 20 and 30, and are arranged without gaps vertically and horizontally. In contrast, the reduced-size cells 20 and 30, as shown in Figures 6(C) and 6(D), form a rhombus (square) with half the area of ​​the standard size, and are arranged so that their diagonals align with the arrangement direction of the cells 20 and 30.

[0057] The reduced-size cells 20 and 30 are arranged vertically and horizontally with the same array pitch P as the normal-size cells 20 and 30. Then, in the area where the reduced-size cells 20 and 30 are arranged, gaps S of the same size as the reduced-size cells 20 and 30 are formed adjacent to each cell 20 and 30 in the diagonal direction, as shown in Figures 6(C) and 6(D). For this reason, as described above, by shifting the center of one cell 20 and the center of the other cell 30 by half the array pitch P in the vertical and horizontal directions, the reduced-size cells 20 and 30 of the two two-dimensional symbols 2 and 3 are arranged without gaps and without overlap in the overlapping area 11, as shown in Figure 6(E).

[0058] Thus, in the overlapping region 11, the cells 20 and 30, which are arranged without gaps at a reduced size, can be accurately identified by the respective two-dimensional symbol reading programs 2 and 3. The matrix-type two-dimensional symbol reading program identifies the center coordinates of each cell 20 and 30 based on the finder patterns 23, 34, 35, etc., and identifies whether the cells 20 and 30 in the coding regions 22 and 32 are light or dark based on the color of the pixel at the center of each cell 20 and 30.

[0059] Specifically, when the image of the composite two-dimensional symbol 1 is processed by a QR code reading program, the reading program detects the finder pattern 23 of the QR code 2, identifies the center coordinates of the cells 20 of the QR code 2 based on the detected finder pattern 23, and identifies whether the cells 20 in the encoded region 22 are light or dark based on the color of the pixels at the center of each cell 20. At this time, since the centers of the reduced-size cells 20 in the overlapping region 11 are arranged with the same array pitch P as the centers of the normal-size cells 20, the center coordinates of each cell 20 (the intersection of xQR and yQR in Figure 6(E)) are correctly identified for the reduced-size cells 20 as well, and the lightness or darkness of the cells 20 is accurately identified.

[0060] Similarly, when the image of the composite two-dimensional symbol 1 is processed by the data matrix reading program, the reading program detects the finder pattern (L-shaped pattern 34 and clock pattern 35) of the data matrix 3, identifies the center coordinates of the cells 30 of the data matrix 3 based on the detected finder pattern, and identifies whether the cells 30 in the encoded region 32 are light or dark based on the color of the pixels at the center of each cell 30. At this time, since the centers of the reduced-size cells 30 in the overlapping region 11 are arranged with the same array pitch P as the centers of the normal-size cells 30, the center coordinates of each cell 30 (the intersection of xDM and yDM in Figure 6(E)) are correctly identified for the reduced-size cells 30 as well, and the lightness or darkness of the cells 30 is accurately identified.

[0061] Furthermore, in the composite two-dimensional symbol 1, some of the cells 20 and 30 included in the overlapping region 11 are displayed at their normal size, while others are omitted and not displayed. Specifically, as shown in Figure 5, in the overlapping region 11, the cells 30 of the data matrix 3 that constitute the clock pattern 35 are displayed at their normal size, while the remaining cells 30 are displayed at a reduced size. In contrast, in the QR code 2, in the overlapping region 11, the cells 20 in the portion 11a that overlaps with the normal-sized cells 30 of the data matrix 3 are omitted and not displayed, while the remaining cells 20 are displayed at a reduced size. The reason for displaying one set of cells 30 at their normal size and the other set of cells 20 in this way is that if the clock pattern 35 were displayed with reduced-sized cells 30, the readability of the data matrix 3 would decrease, while the omission of cells 20 in the encoding region 22 of the QR code 2 is within the range that can be error-corrected, so the readability of the QR code 2 is hardly reduced. Specifically, the absence of cell 20 in the encoded area 22 of QR code 2 can be corrected with about half of the error correction function (30%) of QR code 2.

[0062] Thus, if the overlapping region 11 contains a portion where displaying cells 20 and 30 in a reduced size would impair the readability of the two-dimensional symbols 2 and 3, it is desirable to display that portion with cells 20 and 30 of the other two-dimensional symbol 2 and 30 to the extent that error correction is possible. On the other hand, with respect to the coding regions 22 and 32, as described above, even if cells 20 and 30 are displayed in a reduced size, the color scheme pattern can still be identified. Therefore, it is desirable to display all cells 20 and 30 in a reduced size, as in this embodiment, at least in the portion where the coding regions 22 and 32 of the two two-dimensional symbols 2 and 3 overlap. In this embodiment, the cell 20 of the alignment pattern 26 of the QR code 2 is also displayed in a reduced size in the overlapping region 11 (see Figures 2 and 5), because displaying the alignment pattern 26 in a reduced size does not significantly affect the readability of the QR code 2.

[0063] As described above, in the composite two-dimensional symbol 1, the cells 20 and 30 of the two two-dimensional symbols 2 and 3 are arranged with a common array direction and array pitch P, offset so that the centers of each cell 20 and 30 do not overlap. Furthermore, the cells 20 and 30 included in the overlapping region 11 are displayed in a reduced size, and the area around the center of each cell 20 and 30 is colored according to the respective color scheme of the cell 20 and 30. Therefore, the color scheme of the cells 20 and 30 displayed in the overlapping region 11 can be accurately read.

[0064] Furthermore, the finder patterns 23, 34, and 35 of the two two-dimensional symbols 2 and 3 are arranged so as not to overlap with each other. In the overlapping region 11, where the clock pattern 35 of the data matrix 3 and the encoding region 22 of the QR code 2 overlap, the clock pattern 35 is displayed in a normal-sized cell 30, and the cells 20 of the QR code 2 are omitted. As a result, each of the finder patterns 23, 34, and 35 included in the composite two-dimensional symbol 1 can be reliably detected by the reading programs for the QR code 2 and the data matrix 3. In addition, the cells 20 of the QR code 2 that are omitted in the overlapping region 11 are within a range that can be corrected with ample margin by the error correction function, so there is no problem in reading the QR code 2.

[0065] Therefore, when the image of the composite two-dimensional symbol 1 of this embodiment is processed with a general QR code reading program, the finder pattern 23 of the QR code 2 is detected, the coordinates of the center of cell 20 in the encoding area 22 are identified based on the finder pattern 23, the color pattern of cell 20 is identified, and the information recorded in the QR code 2 is decoded. Also, when the image of the composite two-dimensional symbol 1 of this embodiment is processed with a general data matrix reading program, the finder patterns 34 and 35 of the data matrix 3 are detected, the coordinates of the center of cell 30 in the encoding area 32 are identified based on the finder patterns 34 and 35, the color pattern of cell 30 is identified, and the information recorded in the data matrix 3 is decoded. In this way, the composite two-dimensional symbol 1 of this embodiment can display two two-dimensional symbols 2 and 3 superimposed on each other as a single unit while maintaining readability.

[0066] In particular, as in this embodiment, when the center of cell 20 of QR code 2 and the center of cell 30 of data matrix 3 are offset by half the array pitch P of each cell 20 and 30 in both the vertical and horizontal array directions, the center of cell 20 of QR code 2 and the center of cell 30 of data matrix 3 can be separated to the maximum extent possible in the overlapping region 11. This makes it possible to suppress as much as possible the mixing of colors between cells 20 and 30 of the two two-dimensional symbols 2 and 3 due to camera shake during imaging.

[0067] Furthermore, as in this embodiment, when the cells 20 and 30 displayed in a reduced size in the overlapping region 11 are arranged as rhombuses with equal areas whose diagonals are aligned along the arrangement direction of the cells 20 and 30, and the cells 20 and 30 of the two two-dimensional symbols 2 and 3 are placed adjacent to each other without gaps, the area of ​​the reduced-size cells 20 and 30 in the overlapping region 11 can be maximized without variation, thereby minimizing the risk of color discrimination errors in cells 20 and 30 due to camera shake during imaging.

[0068] A typical application of the composite two-dimensional symbol 1 is as a product identification symbol displayed on product packaging C, as shown in Figure 7. In the example in Figure 7, a standard data matrix (GS1 data matrix) 3 for recording product identification information and a QR code 2 recording the web address of the manufacturer's product information page are printed together as the composite two-dimensional symbol 1 on product packaging C. When the composite two-dimensional symbol 1 is used as a product identification symbol, as shown in Figure 7, visually identifiable characters 50 indicating the recorded information of the QR code 2 and data matrix 3 can be printed above and below the composite two-dimensional symbol 1.

[0069] By scanning the composite two-dimensional symbol 1 in Figure 7 and processing it with a general data matrix reading program, the product identification information recorded in the data matrix 3 can be decoded. Therefore, with existing accounting registers configured to read the GS1 data matrix and perform accounting processing, if the composite two-dimensional symbol 1 in Figure 7 is held up to the scanner, the product identification information will be read and the purchased product will be identified.

[0070] Furthermore, by capturing the composite two-dimensional symbol 1 in Figure 7 and processing it with a general QR code reading program, the web address recorded in QR code 2 can be decoded. Therefore, if a product purchaser captures the composite two-dimensional symbol in Figure 7 with a QR code reading program on their smartphone, they can display the manufacturer's product information page indicated by the web address in their web browser and obtain information about the purchased product.

[0071] As shown above, the composite two-dimensional symbol 1 in Figure 7 can selectively acquire different information and achieve its respective purpose by using different reading programs. In the case of the composite two-dimensional symbol 1 in which the QR code 2 and data matrix 3 are displayed together, the scanner or camera can be pointed at the same location regardless of which reading program is used, eliminating any hesitation about where to point the scanner or camera.

[0072] The composite two-dimensional symbol 1 in Figure 7 allows product identification information to be read using a general data matrix reading program, and the web address to be read using a general QR code reading program; therefore, a dedicated reading program is not required. On the other hand, a system is also proposed that uses a dedicated reading program to read the information recorded in the two two-dimensional symbols 2 and 3 from the composite two-dimensional symbol 1 in Figure 7, and combine the two pieces of information to obtain detailed product information from a website.

[0073] Specifically, the GS1 data matrix can record not only the product identification code (GTIN) but also attribute information such as the product lot number and serial number. Therefore, the web server for providing product information is configured to provide detailed information (such as the place of manufacture and distribution process) for each lot number and serial number. The proposed system allows users to obtain detailed information about a product by adding the product lot number and serial number recorded in the data matrix 3 to the web address recorded in the QR code 2 of the composite two-dimensional symbol 1 and providing it to the web server.

[0074] Figure 8 is a flowchart showing the processing procedure of a dedicated reading program for the composite two-dimensional symbol 1. This dedicated reading program can be run on the purchaser's smartphone and is used to obtain detailed product information from a web server by combining the product identification code and web address recorded in the composite two-dimensional symbol 1. The details of steps S11 to S15 in Figure 8 are as follows: [S11]: Capture the composite two-dimensional symbol 1 with the smartphone's camera (imaging device). [S12]: Decode the web address recorded in the QR code 2 within the composite two-dimensional symbol 1 using a general QR code reading algorithm. [S13]: Decode the product identification information recorded in the data matrix 3 within the composite two-dimensional symbol 1 using a general data matrix reading algorithm. [S14]: Combine the read web address and product identification information to generate a URL for obtaining detailed product information. The generated URL will be in accordance with the settings on the web server side, but for example, it may be a URL in which the lot number and serial number included in the product identification information are added as URL parameters or subdirectories to the web address recorded in QR code 2. [S15]: Launch the web browser on the smartphone and access the specified destination of the generated URL. Then, the detailed product information provided from the website is displayed on the web browser screen. Of the above steps S11 to S15, the first step relating to the method for reading a composite two-dimensional symbol according to the present invention is realized by step S11, the second step is realized by step S12, the third step is realized by step S13, and the fourth step is realized by step S14.

[0075] Thus, by using a dedicated reading program for the composite two-dimensional symbol 1 to read the recorded information of both two two-dimensional symbols 2 and 3 and combine the two pieces of information, the composite two-dimensional symbol 1 can be used for a third purpose, as shown in Figure 9, which differs from the case where a general QR code or data matrix reading program reads either piece of information individually. While the above dedicated reading program can be run on a purchaser's smartphone, a dedicated reading program for use on a POS register is also feasible. When run on a POS register, it is envisioned to be used, for example, to obtain information from a web server, such as whether the product being sold is from a lot subject to a product recall.

[0076] In the composite two-dimensional symbol 1, the cells 20 and 30 of the two two-dimensional symbols 2 and 3 are regularly arranged with a common arrangement direction and arrangement pitch, and the offset of the centers of the cells 20 and 30 of each other is constant. Therefore, the finder patterns 23, 34, and 35 of one two-dimensional symbol 2 or 3 can be used to identify the positions of the cells 20 and 30 of the other two-dimensional symbol 2 or 3. For this reason, it is also proposed that in the dedicated reading program shown in Figure 8, the finder patterns 34 and 35 of the data matrix 3 be used to determine the center coordinates of the cell 20 of the QR code 2, and the finder pattern 23 of the QR code 2 be used to determine the center coordinates of the cell 30 of the data matrix 3. With such a configuration, the center coordinates of the cells 20 and 30 of the two-dimensional symbols 2 and 3 can be identified even more accurately. Furthermore, even if the finder patterns 23, 34, and 35 of one of the two-dimensional symbols 2 and 3 cannot be detected due to contamination or other reasons, the other two-dimensional symbol 2 and 3 can be read based on the finder patterns 23, 34, and 35 of the other two-dimensional symbol 2 and 3.

[0077] Furthermore, although the dedicated reading program shown in Figure 8 is a program that reads only the composite two-dimensional symbol 1, it is also proposed that it be used in conjunction with the QR code 2 and data matrix 3 reading programs. For example, identification information indicating that it is the composite two-dimensional symbol 1 and the type (standard) of the other two-dimensional symbols 2 and 3 is recorded in the QR code 2 and / or data matrix 3 included in the composite two-dimensional symbol 1. The dedicated reading program is then proposed to output only the recorded information of the first two-dimensional symbol 2 and 3 if the recorded information of the first two-dimensional symbol 2 and 3 does not include the identification information, and to read the recorded information of the second two-dimensional symbol 2 and 3 based on the identification information and perform a process to combine the two recorded information.

[0078] Next, the method for generating the composite two-dimensional symbol 1 described above will be explained. Figure 10 is a flowchart showing the processing procedure of the program for generating the composite two-dimensional symbol 1. The details of steps S21 to S25 in Figure 10 are as follows: [S21]: Prepare the information to be recorded in the QR code 2 (Web address) and the information to be recorded in the data matrix 3 (product identification information). [S22]: Generate data for the color scheme of the data matrix 3 that records the required information (product identification information) according to a general generation algorithm for data matrices. Here, the size (number of cells) of the data matrix 3 is determined to be the minimum size in which the required information can be recorded. [S23]: Generate data for the color scheme of the QR code 2 that records the required information (Web address) according to a general generation algorithm for QR codes. As described above, the QR code 2 compensates for the absence of color schemes in cells 20 of the coding area 22 by an error correction function, so the error correction function is set to the highest level (error correction rate of 30%). The size (number of cells) of the QR code 2 is determined according to the amount of data of the information to be recorded and the size of the data matrix 3 generated in step S22. As the size (number of cells) of the data matrix 3 increases, the overlapping area 11 widens and the number of missing cells 20 in the encoded area 22 increases. Therefore, the size of the QR code 2 is determined to be such that the missing cells 20 can be corrected with margin by the error correction function. Specifically, it is proposed that the size of the QR code be determined to be such that the missing cells 20 can be corrected with an error correction rate of less than half (less than 15%). [S24]: Data for the color scheme pattern of the composite two-dimensional symbol 1, which is created by superimposing the QR code 2 and the data matrix 3 generated in steps S22 and S23, is generated. Which areas of the QR code 2 and which areas of the data matrix 3 are superimposed is determined according to the size (number of cells) of the QR code 2 and the data matrix 3. Basically, the two two-dimensional symbols 2 and 3 are arranged so that, as shown in Figure 4, the parts of the data matrix 3 other than the L-shaped pattern 34 are superimposed on the lower right of the QR code 2. [S25]: Image data for printing is generated from the color scheme data of the composite two-dimensional symbol 1 and printed on an object such as a product package C, either alone or in combination with the surrounding image.Of the steps S21 to S25 described above, the first step relating to the image data generation method according to the present invention is realized by step S24, the second step is realized by step S23, and the third step is realized by step S22.

[0079] As shown in Figure 11, the composite two-dimensional symbol 1a of this embodiment is formed by superimposing a QR code 2a and an Aztec code 4 and displaying them as a single unit. As shown in Figure 12(A), the Aztec code 4 is a matrix-type two-dimensional symbol formed by arranging square-shaped cells 40 vertically and horizontally, and each cell 40 is colored either light (white) or dark (black). As shown in Figure 12(B), the Aztec code 4 is broadly divided into two areas, a functional pattern 41 and an encoded area 42, similar to the QR code 2 and the data matrix 3. In Figure 12(B), the area where the cells 40 are represented in white or black corresponds to the functional pattern 41, and the area where the cells 40 are displayed in shaded areas corresponds to the encoded area 42. Note that the configuration of the QR code 2a is the same as the QR code 2 of Embodiment 1, so common components are denoted by common reference numerals in the text and figures and detailed explanations are omitted.

[0080] As shown in Figure 12(B), the functional pattern 41 of the Aztec code 4 consists of a finder pattern 43 for detecting the position of a symbol and an orientation pattern 44 for detecting the orientation of a symbol. The finder pattern 43 is a concentric square pattern placed in the center of the symbol, and the orientation pattern 44 is placed at the four corners of the finder pattern 43.

[0081] As shown in Figure 12(B), the encoding area 42 of the Aztec code 4 is composed of a data code area 45 and a formal information code area 46. The data code area 45 is provided with codewords, each consisting of 6 bits. The codewords consist of data codewords for recording data, error correction codewords for correcting errors in the data codewords, and filler codewords to fill the remaining area of ​​the data code area 45. The formal information code area 46 records information such as the size of the Aztec code 4. Because the encoding area 42 has an error correction function built in, even if the brightness of cell 40 is misidentified due to soiling of the printed material or blurring of the image when reading the Aztec code 4, the recorded data can be read correctly as long as the error is below a predetermined percentage. The Aztec code 4 conforms to ISO / IEC 24778:2008, so a detailed explanation is omitted.

[0082] As shown in Figure 13, in the composite two-dimensional symbol 1a, the entire Aztec code 4 is superimposed on the central and lower right portion of the QR code 2a. That is, the entire Aztec code 4 is included in the overlapping region 11. In the QR code 2a, a portion of the encoding region 22 and the entire alignment pattern 26 are included in the overlapping region 11, while the remainder of the encoding region 22 and the entire finder pattern 23, separation pattern 24, and timing pattern 25 are included in the separate region 10.

[0083] In the composite two-dimensional symbol 1a of this embodiment, similar to Embodiment 1, the two two-dimensional symbols 2a and 4 are superimposed with the arrangement direction and arrangement pitch of cells 20 and 40 aligned. Furthermore, to prevent the centers of the respective cells 20 and 40 from overlapping, the centers of one cell 20 and the other cell 40 are offset by half the arrangement pitch of the cells 20 and 40 in the vertical and horizontal directions, respectively. As shown in Figure 13, the cells 20 and 40 included in the overlapping region 11 are displayed at a reduced size, similar to Embodiment 1, so that the area around the center of each cell 20 and 40 is colored according to the respective color scheme of the cells 20 and 40.

[0084] Furthermore, in this embodiment, in the overlapping region 11, the cells 40 of the Aztec code 4 are displayed at their normal size if they constitute the finder pattern 43, while the remaining cells 40 are displayed at a reduced size. In the overlapping region 11, the cells 20 of the QR code 2a that overlap with the finder pattern 43 of the Aztec code 4 are omitted and not displayed, while the remaining cells 20 are displayed at a reduced size. If the finder pattern 43 of the Aztec code 4 is displayed with reduced-size cells 40, the readability of the Aztec code 4 is significantly reduced. On the other hand, even if cells 20 of the alignment pattern 26 in the encoding region 22 of the QR code 2a are omitted, the readability of the QR code 2a is hardly reduced as long as it is within the range where error correction is possible.

[0085] As described above, in the composite two-dimensional symbol 1a of this embodiment, the cells 20 and 40 of the two two-dimensional symbols 2a and 4 are arranged with a common arrangement direction and arrangement pitch P, offset so that the centers of each cell 20 and 40 do not overlap. Furthermore, the cells 20 and 40 included in the overlapping region 11 are displayed in a reduced size, and the area near the center of each cell 20 and 40 is colored according to the respective color scheme of the cell 20 and 40. Therefore, the color schemes of the cells 20 and 40 displayed in the overlapping region 11 can be accurately identified.

[0086] Furthermore, the finder patterns 23 and 43 of the two two-dimensional symbols 2 and 3 are arranged so as not to overlap with each other. Also, the finder pattern 43 included in the overlapping area 11 is displayed in a normal-sized cell 40, and the cell 20 of the QR code 2a that overlaps with the finder pattern 43 is omitted. As a result, each of the finder patterns 23 and 43 included in the composite two-dimensional symbol 1 can be reliably detected by the QR code and Aztec code reading program. In addition, the cell 20 of the QR code 2a that is omitted in the overlapping area 11 is within a range that can be corrected with ample margin by the error correction function, so there is no problem in reading the QR code 2a.

[0087] Therefore, when the image of the composite two-dimensional symbol 1a of this embodiment is processed with a general QR code reading program, the finder pattern 23 of the QR code 2 is detected, the coordinates of the center of the cell 20 in the encoding area 22 are identified based on the finder pattern 23, the color pattern of the cell 20 is identified, and the information recorded in the QR code 2 is decoded. Similarly, when the image of the composite two-dimensional symbol 1 of this embodiment is processed with a general Aztec code reading program, the finder pattern 43 of the Aztec code 4 is detected, the coordinates of the center of the cell 40 in the encoding area 42 are identified based on the finder pattern 43, the color pattern of the cell 40 is identified, and the information recorded in the Aztec code 4 is decoded. In this way, even with the composite two-dimensional symbol 1a of this embodiment, the two two-dimensional symbols 2a and 4 can be displayed as a single integrated image by overlapping them on a large scale while maintaining readability.

[0088] As shown in Figure 14, the composite two-dimensional symbol 1b of this embodiment is formed by superimposing two QR codes 2b and 2c and displaying them as a single unit. Since the configuration of QR codes 2b and 2c is the same as that of QR code 2 in Embodiment 1, common components are denoted by common reference numerals in the text and figures, and detailed explanations are omitted.

[0089] In the composite two-dimensional symbol 1b of this embodiment, as shown in Figure 14, the two QR codes 2b and 2c are arranged so that the lower right corners of their respective centers overlap, with one QR code 2c rotated 180° relative to the other QR code 2b. By overlapping the two QR codes 2b and 2c in this way, the two QR codes 2b and 2c can be largely overlapped, while each finder pattern 23 can be placed entirely in separate regions 10a and 10b without overlapping with the other QR code 2b or 2c.

[0090] In this embodiment as well, the two QR codes 2b and 2c are superimposed with the arrangement direction and arrangement pitch of their respective cells 20 aligned. Furthermore, to prevent the centers of their respective cells 20 from overlapping, the centers of the cells 20 of one QR code 2b and the centers of the cells 20 of the other QR code 2c are offset by half the arrangement pitch of the cells 20 in the vertical and horizontal directions. With this configuration, even if the two QR codes 2b and 2c overlap significantly, the color patterns of the cells 20 displayed in the overlapping area 11 can be accurately identified, allowing the two QR codes 2b and 2c to be displayed as a single, integrated unit while maintaining readability.

[0091] Thus, the two two-dimensional symbols constituting the composite two-dimensional symbol according to the present invention may be of the same standard and have the same shape of finder pattern. Although the two QR codes 2b and 2c constituting the composite two-dimensional symbol 1b in Figure 14 have the same number of cells (same version), the composite two-dimensional symbol according to the present invention can also be composed of QR codes with different numbers of cells (different versions).

[0092] One application of the composite two-dimensional symbol 1b in Example 3 is, for example, as shown in Figure 15(A), a two-dimensional symbol used in printed materials such as informational posters and brochures to guide users to a web page that displays information in different languages. In the example in Figure 15(A), the address of a web page that provides predetermined information in Japanese is recorded in the QR code 2b in the upper left, and the address of a web page that provides the same information in English is recorded in the QR code 2c in the lower right. Then, the guidance text 51a in "Japanese" is displayed in the upper left of the composite two-dimensional symbol 1b, and the guidance text 51b in "English" is displayed in the lower right of the composite two-dimensional symbol 1b.

[0093] In other words, those who wish to access Japanese information can scan the center to upper left portion of the composite two-dimensional symbol 1b in Figure 15(A) using a smartphone's QR code reading program. By reading the web address recorded in the upper left QR code 2b, they can display the Japanese web page in their web browser. Similarly, those who wish to access English information can scan the center to lower right portion of the composite two-dimensional symbol 1b in Figure 15(A) using a smartphone's QR code reading program. By reading the web address recorded in the lower right QR code 2c, they can display the English web page in their web browser.

[0094] As described above, the composite two-dimensional symbol 1a shown in Figure 15(A) allows access to information displayed in a desired language by adjusting the imaging range of the QR code reading program. Furthermore, since the two QR codes 2b and 2c are displayed largely overlapping as a single unit in this composite two-dimensional symbol 1a, it has the advantage of reducing the printing space required compared to printing the two QR codes side by side.

[0095] Furthermore, the composite two-dimensional symbol 1b of Example 3 can also be used as a two-dimensional symbol for product identification displayed on the product package C, in the same manner as the composite two-dimensional symbol 1 of Example 1 (see Figure 7), as shown in Figure 15(B). That is, in the example of Figure 15(B), product identification information is recorded in the QR code 2b in the upper left, and the web address of the manufacturer's product information page is recorded in the QR code 2c in the lower right. Visual characters 50 indicating the recorded information of the QR code 2b in the upper left are printed above the composite two-dimensional symbol 1b, and visual characters 50 indicating the recorded information of the QR code 2c in the lower right are printed below the composite two-dimensional symbol 1b. The composite two-dimensional symbol 1b shown in Figure 15(B) allows for the selective acquisition of product identification information and web address information by adjusting the imaging range of the composite two-dimensional symbol 1b using a QR code reading program.

[0096] Furthermore, similar to Example 1, a system is proposed in which, using a dedicated reading program, information recorded in two QR codes 2b and 2c from the composite two-dimensional symbol 1b shown in Figure 15(B) is read, and the two pieces of information are combined to obtain detailed product information from a website.Regarding the composite two-dimensional symbol 1b of Example 3, when the information recorded in the two QR codes 2b and 2c is to be read by the dedicated reading program, it is proposed that identification information be stored in each QR code 2b and 2c to distinguish them from each other, in order to prevent the dedicated reading program from reading each QR code 2b and 2c twice.In addition, it is proposed that attribute information indicating the attributes of the data to be recorded in each QR code 2b and 2c be recorded so that the dedicated reading program can easily process the data read from each QR code 2b and 2c.It is proposed that such identification information and attribute information be recorded in the remaining area of ​​the data code area 27 after the data codeword and error correction codeword have been recorded. Since this remaining area is where filler codewords are recorded and is not read by general-purpose QR code reading programs, recording identification information and attribute information in this remaining area eliminates the risk of general-purpose reading programs being hindered by the identification information and attribute information.

[0097] Figure 16 is a flowchart showing the processing procedure of a dedicated reading program for the composite two-dimensional symbol 1b, which can be run on a smartphone. The details of steps S31 to S35 in Figure 16 are as follows: [S31]: Capture an image of the entire composite two-dimensional symbol 1b using the smartphone's camera (imaging device). [S32]: Decode the data recorded in one of the QR codes 2b, 2c within the composite two-dimensional symbol 1b using a general QR code reading algorithm. Specifically, the finder patterns 23 of the QR codes 2b, 2c are searched for in the image captured in step S31, and the data recorded in the QR code 2b, 2c whose finder pattern 23 was detected first is decoded. [S33]: A modified image is generated by blacking out the portion of the finder pattern 23 detected in step S32 in the image captured in step S31. [S34]: Decode the data recorded in the second QR code 2b, 2c included in the modified image generated in step S33 using a general QR code reading algorithm. In the modified image, the finder pattern 23 of the first QR code 2b, 2c is blacked out, making it difficult to detect, so the first QR code 2b, 2c will not be read twice in this step. [S35]: Processing is performed based on the data read from the two QR codes 2b, 2c. The specific processing content is determined according to the data recorded in the two QR codes 2b, 2c and the purpose of the program, so a detailed explanation is omitted. Of the above steps S31 to S35, the imaging step related to the method for reading a composite two-dimensional symbol according to the present invention is realized in step S31, the first decoding step is realized in step S32, the image modification step is realized in step S33, and the second decoding step is realized in step S34.

[0098] As with the dedicated reading program described above, after reading the first QR codes 2b and 2c, a modified image is generated in which the finder pattern 23 of the first QR codes 2b and 2c is modified to be difficult to read. By then executing the process of reading the second QR codes 2b and 2c based on this modified image, the finder pattern 23 of the first QR codes 2b and 2c will no longer be detected during the process of reading the second QR codes 2b and 2c. Therefore, the dedicated reading program described above can reliably detect the finder pattern 23 of the second two-dimensional symbols 2b and 2c in a short amount of time.

[0099] Although embodiments of the present invention have been described above, the present invention is not limited to the configuration of the above embodiments, and the configuration of the above embodiments can be modified in various ways without departing from the spirit of the present invention. For example, in the above embodiments, an example was shown in which the composite two-dimensional symbol 1 is printed on product packaging C, but the present invention is not limited to product packaging and can be applied to printed materials in general. Furthermore, the composite two-dimensional symbol according to the present invention is not limited to those printed on printed materials, but may also be displayed on a liquid crystal display or the like.

[0100] Furthermore, while the above embodiment shows an example of overlaying a data matrix, Aztec code, and QR code onto a QR code, matrix-type two-dimensional symbols of other standards can be overlaid in the same manner. It is desirable to place parts of the symbol that are important for position detection, such as finder patterns, outside the overlapping area. If they are placed within the overlapping area, it is desirable to display them in a normal-sized cell and to omit the cells of the other two-dimensional symbol.

[0101] In the above embodiment, the cells 20 and 30 displayed in the overlapping region 11 in a reduced size form a rhombus (square) with an area half that of the normal size, as shown in Figure 6(E). However, the shape of the reduced-size cells 20 and 30 can be changed in various ways. For example, as shown in Figure 17(A), the reduced-size cells 20 and 30 may be circular. Alternatively, as shown in Figure 17(B), the reduced-size cells 20 and 30 may be square with an area quarter that of the normal size.

[0102] Furthermore, in the above embodiment, the centers of the cells 20 and 30 of the two two-dimensional symbols 2 and 3 are offset vertically and horizontally. However, as shown in Figure 17(B), if the area of ​​the reduced-size cells 20 and 30 is made into a square shape that is 1 / 4 the size of the normal size, gaps will be created on all sides of the cells 20 and 30. Therefore, the centers of the cells 20 and 30 of the two two-dimensional symbols 2 and 3 may be offset vertically or horizontally.

[0103] Furthermore, while the composite two-dimensional symbol 1 in the above embodiment is formed by integrally superimposing two two-dimensional symbols 2 and 3, the composite two-dimensional symbol of the present invention may be formed by superimposing three or more two-dimensional symbols. For example, as shown in Figure 17(B), if the reduced-size cells 20 and 30 are configured as squares with an area of ​​1 / 4 of the normal size, gaps will be created on the top, bottom, left, and right sides of cells 20 and 30. In such gaps, cells of the third and fourth two-dimensional symbols can be placed in reduced sizes so as not to overlap with cells 20 and 30 of the first and second two-dimensional symbols 2 and 3.

[0104] Furthermore, while the two-dimensional symbols 2, 3, and 4 in the above embodiment have a square shape in which the number of cells 20, 30, and 40 arranged and their arrangement pitch are equal in the vertical and horizontal directions, the two-dimensional symbols according to the present invention may be rectangular in shape in which the number of cells arranged and their arrangement pitch differ in the vertical and horizontal directions.

[0105] Furthermore, in the above embodiment, the dark cells 20, 30, and 40 are colored black, and the light cells 20, 30, and 40 are colored white. However, each cell 20, 30, and 40 may be colored with a color other than black and white. Also, the light and dark cells do not need to be colored with a single color. For example, a composite two-dimensional symbol may contain a mixture of cells colored with a first light color, cells colored with a second light color, cells colored with a first dark color, and cells colored with a second dark color. Doing so can improve the design of the composite two-dimensional symbol. Note that reading programs such as QR codes and data matrices only need to identify whether each cell is colored with a light or dark color, so even if cells are colored with multiple types of light or dark colors, there will be no problem in reading the two-dimensional symbol.

[0106] Furthermore, the two-dimensional symbols included in the composite two-dimensional symbols according to the present invention may record multiple bits of data in a single cell. Specifically, an example is a two-dimensional symbol in which a single cell is encoded with 2 bits by selectively coloring each cell with a first light color, a second light color, a first dark color, and a second dark color.

[0107] Furthermore, while the above embodiment exemplifies the use of recording a web address and product identification information in the two-dimensional symbols included in the composite two-dimensional symbol, the recorded data of the two-dimensional symbols constituting the composite two-dimensional symbol according to the present invention is not particularly limited, and various types of data can be recorded. For example, a message may be recorded in one two-dimensional symbol, and an electronic signature to indicate that the message has not been tampered with, or an error correction code to correct errors in the message, may be recorded in the other two-dimensional symbol. It is also proposed to record the same message in both two-dimensional symbols to prevent the two-dimensional symbols from becoming unreadable due to contamination.

[0108] 1, 1a, 1b Composite 2D Symbol 2, 2a, 2b QR Code (First 2D Symbol) 2c QR Code (Second 2D Symbol) 3 Data Matrix (Second 2D Symbol) 4 Aztec Code (Second 2D Symbol) 10 Overlap Area 11 Single Area 20, 30, 40 Cell 21, 31, 41 Functional Pattern 22, 32, 42 Encoding Area 23, 43 Finder Pattern 24 Separation Pattern 25 Timing Pattern 26 Alignment Pattern 27, 45 Data Code Area 28, 46 Formal Information Code Area 34 L-shaped Pattern (Finder Pattern) 35 Clock Pattern (Finder Pattern) 44 Orientation Pattern 50 Visually Readable Characters 51, 51b Instruction Text C Product Packaging (Printed Material)

Claims

1. A printed material having a first two-dimensional symbol and a second two-dimensional symbol arranged thereon, wherein the first two-dimensional symbol and the second two-dimensional symbol are matrix-type symbols formed by arranging light and dark colored cells vertically and horizontally, each comprising a finder pattern for detecting the position of the symbol and an encoding area for recording data, the finder patterns of the first two-dimensional symbol and the second two-dimensional symbol are arranged so as not to overlap each other, the encoding areas of the first two-dimensional symbol and the second two-dimensional symbol each have an error correction function and are arranged so that parts of them overlap each other, the cells of the first two-dimensional symbol and the second two-dimensional symbol are arranged with a common arrangement direction and arrangement pitch, and their respective centers do not overlap, and in the parts where their respective encoding areas overlap, the centers of each cell are colored according to the respective cell's color scheme pattern.

2. The printed material according to claim 1, characterized in that the center of the cell of the first two-dimensional symbol and the center of the cell of the second two-dimensional symbol are offset by half the arrangement pitch of the respective cells in both the vertical and horizontal arrangement directions.

3. The printed material according to claim 2, characterized in that in the portion where the encoding areas of the first two-dimensional symbol and the second two-dimensional symbol overlap, the cells of the first two-dimensional symbol and the second two-dimensional symbol form a rhombus of equal area and are arranged adjacent to each other without gaps.

4. The printed material according to any one of claims 1 to 3, wherein the first two-dimensional symbol is a rectangular two-dimensional symbol having finder patterns at three corners, the second two-dimensional symbol is a rectangular two-dimensional symbol having the same finder patterns at three corners as the first two-dimensional symbol, and the first two-dimensional symbol and the second two-dimensional symbol are arranged such that the corners without finder patterns overlap each other, and all finder patterns do not overlap each other, by rotating the other two-dimensional symbol by 180° relative to one of the two-dimensional symbols.

5. The printed material according to claim 4, characterized in that the first two-dimensional symbol and the second two-dimensional symbol are QR codes.

6. The printed material according to claim 5, wherein the first two-dimensional symbol and the second two-dimensional symbol each have a data code area on which a data code word for recording data and an error correction code word for correcting errors in the data code word are recorded, and the data code area further comprises an area in the remaining area after the data code word and the error correction code word have been recorded for recording identification information that allows the first two-dimensional symbol and the second two-dimensional symbol to be mutually distinguishable.

7. The printed material according to claim 5, wherein the first two-dimensional symbol and the second two-dimensional symbol each have a data code area on which a data code word for recording data and an error correction code word for correcting errors in the data code word are recorded, and the data code area further comprises an area in the remaining area after the data code word and the error correction code word have been recorded for recording attribute information indicating the attributes of the data recorded by the data code word.

8. The printed material according to any one of claims 1 to 3, characterized in that the finder patterns of the first two-dimensional symbol and the second two-dimensional symbol are composed of rectangular cells whose side length is equal to the cell array pitch, and in the overlapping portion of the finder pattern of one of the two-dimensional symbols and the encoding area of ​​the other two-dimensional symbol, the color scheme pattern of the cells of the other two-dimensional symbol is missing.

9. The printed material according to any one of claims 1 to 3, wherein the first two-dimensional symbol is a rectangular two-dimensional symbol having finder patterns at three corners, the corner without a finder pattern overlapping with the second two-dimensional symbol, and all finder patterns are arranged so as not to overlap with the second two-dimensional symbol, and the second two-dimensional symbol is a rectangular two-dimensional symbol having finder patterns on all four sides, the finder patterns on two sides overlapping with the first two-dimensional symbol, and the finder patterns on the remaining two sides not overlapping with the first two-dimensional symbol.

10. A composite two-dimensional symbol comprising a first two-dimensional symbol and a second two-dimensional symbol arranged in a superimposed manner, wherein the first two-dimensional symbol and the second two-dimensional symbol are matrix-type symbols comprising light and dark colored cells arranged vertically and horizontally, each comprising a finder pattern for detecting the position of the symbol and an encoding area for recording data, the finder patterns of the first two-dimensional symbol and the second two-dimensional symbol are arranged so as not to overlap each other, the encoding areas of the first two-dimensional symbol and the second two-dimensional symbol each have an error correction function and are arranged so that parts of them overlap each other, the cells of the first two-dimensional symbol and the second two-dimensional symbol are arranged with a common arrangement direction and pitch, and their respective centers do not overlap, and in the parts where their respective encoding areas overlap, the centers of each cell are colored according to the respective cell's color scheme pattern.

11. The composite two-dimensional symbol according to 10, wherein the first two-dimensional symbol is a rectangular QR code having finder patterns at three corners, the second two-dimensional symbol is a rectangular QR code having finder patterns of the same size as the first two-dimensional symbol at three corners, and the first two-dimensional symbol and the second two-dimensional symbol are arranged such that the corners without finder patterns overlap each other, and all of the finder patterns do not overlap each other, by rotating the other two-dimensional symbol by 180° relative to one of the two-dimensional symbols.

12. A method for displaying a composite two-dimensional symbol by superimposing a first two-dimensional symbol and a second two-dimensional symbol, wherein the first two-dimensional symbol and the second two-dimensional symbol are matrix-type symbols formed by arranging light and dark colored cells vertically and horizontally, each comprising a finder pattern for detecting the position of the symbol and an encoding area for recording data, each encoding area being equipped with an error correction function, the finder patterns of the first two-dimensional symbol and the second two-dimensional symbol being displayed so as not to overlap with each other, the encoding areas of the first two-dimensional symbol and the second two-dimensional symbol being displayed so as to partially overlap with each other, the cells of the first two-dimensional symbol and the second two-dimensional symbol being arranged with a common arrangement direction and pitch so as not to overlap their respective centers, and in the parts where their respective encoding areas overlap, the centers of each cell being displayed with the respective cell's color scheme pattern.

13. An image data generation method for generating image data of a composite two-dimensional symbol according to claim 10 or claim 11, comprising a first step in which a computer generates data indicating a color scheme pattern of the composite two-dimensional symbol based on data indicating a color scheme pattern of the cells of the first two-dimensional symbol and data indicating a color scheme pattern of the cells of the second two-dimensional symbol, wherein the first step determines which regions of the first two-dimensional symbol and which regions of the second two-dimensional symbol will be superimposed based on the number of cells of the first two-dimensional symbol and the number of cells of the second two-dimensional symbol.

14. The image data generation method according to 13, wherein the composite two-dimensional symbol is arranged such that at least a portion of the finder pattern of the second two-dimensional symbol overlaps with the encoding region of the first two-dimensional symbol, and the color scheme pattern of the cells of the first two-dimensional symbol is missing in the overlapping portion of the finder pattern of the second two-dimensional symbol and the encoding region of the first two-dimensional symbol, and the method comprises, before the first step, a second step in which the computer generates data indicating the color scheme pattern of the cells of the first two-dimensional symbol based on data recorded in the first two-dimensional symbol, and before the second step, a third step in which the computer generates data indicating the color scheme pattern of the cells of the second two-dimensional symbol based on data recorded in the second two-dimensional symbol, wherein in the second step, the number of cells of the first two-dimensional symbol is determined in accordance with the number of cells of the second two-dimensional symbol.

15. A method for reading a composite two-dimensional symbol according to claim 10, comprising: a first step of a computer acquiring an image of the composite two-dimensional symbol captured by an imaging device; a second step of the computer decoding the recording information of the first two-dimensional symbol based on the image; a third step of the computer decoding the recording information of the second two-dimensional symbol based on the image; and a fourth step of the computer combining the decoding recording information of the two two-dimensional symbols to generate new information.

16. The method for reading a composite two-dimensional symbol according to 15, characterized in that the recorded information of the first two-dimensional symbol is a web address providing product information, the recorded information of the second two-dimensional symbol is product identification information, and the new information is a URL that includes a subdirectory and / or URL parameters generated from part or all of the product identification information in addition to the web address.

17. A method for reading a composite two-dimensional symbol according to claim 11, comprising: an imaging step in which a computer acquires an image of the composite two-dimensional symbol captured by an imaging device; a first decoding step in which the computer searches for finder patterns of the first two-dimensional symbol and the second two-dimensional symbol included in the image and decodes the recorded information of the two-dimensional symbol relating to the previously detected finder pattern; an image modification step in which the computer generates a modified image of the image in which the finder pattern previously detected in the second step has been modified to a manner in which it is difficult to detect; and a second decoding step in which the computer searches for an unmodified finder pattern included in the modified image and decodes the recorded information of the two-dimensional symbol relating to the detected finder pattern.

18. A method for reading a composite two-dimensional symbol according to any one of claims 15 to 17, characterized in that it is configured to perform a process of determining the position of the center of a cell of the other two-dimensional symbol based on the finder pattern of one of the two-dimensional symbols, or the finder patterns of both of the two-dimensional symbols.

Images