Two-dimensional symbols, programs, and methods for reading two-dimensional symbols.

Abstract

To provide a two-dimensional symbol which is excellent in design and can be easily read as compared with a conventional two-dimensional symbol.SOLUTION: A multilayer circular module arrangement region 4 is provided where a plurality of circular module layers 3 are provided concentrically. Each of the module layers 3 forming the module arrangement region 4 is set to have the same thickness and is divided by a line segment extended in a radial direction into modules 2 having the same area. This arrangement reduces angularity of a two-dimensional symbol 1 and improves its design. Further, since the modules 2 have the same area and a substantially same shape, the symbol can be easily read similarly to a matrix type two-dimensional symbol.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a two-dimensional symbol for recording data by a color pattern of a plurality of modules.

Background Art

[0002] A matrix-type two-dimensional symbol represented by a QR code (registered trademark) has a rectangular shape formed by arranging square modules of the same size vertically and horizontally, and records data by coloring each module white or black. Also, although the modules of the QR code are square, configurations have been proposed in which the modules are not square but star-shaped or circular (for example, Patent Document 1). Further, there is also known a technique in which the modules are selectively colored not with two colors of white and black but with three or more colors, and one or more bits of data can be recorded in one module (for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, QR codes are not limited to production sites and logistics sites, but are also displayed on product packages and advertisements, etc., and the opportunity for general consumers to read QR codes using mobile terminals has been increasing. However, QR codes were devised with the assumption of use in production sites and logistics sites, and their use on product packages and advertisements that consumers see has not been considered. For this reason, the angular shape of the QR code displayed on product packages and advertisements often does not harmonize with the design of the product packages and advertisements, and often impairs the design quality.

[0005] The two-dimensional symbol in Patent Document 1 improves its design by creating gaps between modules, making each module star-shaped or circular. However, since the modules are arranged vertically and horizontally, similar to QR codes, the overall two-dimensional symbol is angular. Also, because gaps exist between the modules, its readability is somewhat inferior to that of QR codes. Furthermore, the two-dimensional symbol in Patent Document 2 is superior in design to QR codes because the modules are colored with three or more chromatic colors. However, this configuration does not eliminate the angular shape of the modules or the two-dimensional symbol.

[0006] This invention has been made in view of the current situation, and aims to provide a two-dimensional symbol that is aesthetically pleasing and possesses the same readability as conventional matrix-type two-dimensional symbols. [Means for solving the problem]

[0007] After much trial and error in an attempt to solve the above problem, the inventor discovered that concentric rings of the same thickness could be divided into approximately identical shapes and areas, thus completing the present invention. In other words, the present invention is a two-dimensional symbol that records data by a color scheme pattern of modules, comprising a multilayer annular or multilayer sub-annular module array region in which a plurality of module layers having an annular or partial annular shape are arranged adjacently in a concentric or concentric arc shape, wherein all of the module layers constituting the module array region have the same thickness and are equally divided into modules of the same area by line segments extending in the radial direction of the module layer.

[0008] Here, the "thickness" of the module layer is the difference between the outer radius and the inner radius of a module layer that has an annular or partially annular shape, and the "radial direction" is the direction along the radial direction from the center of the module layer. In this configuration, since the module array area is multi-layered annular or multi-layered sub-annular, the angularity of the two-dimensional symbol is reduced compared to conventional matrix-type two-dimensional symbols, resulting in superior design. Therefore, the two-dimensional symbol according to the present invention can be displayed without any sense of incongruity on product packaging and advertisements where a curved design is required. Furthermore, in general, existing matrix-type two-dimensional symbols have uniform sizes and shapes for all modules to prevent variations in the ease of distinguishing module colors (the degree to which a reader can correctly distinguish module colors under the influence of disturbances such as camera shake or out-of-focus images). In contrast, although the modules arranged in the module array area according to the present invention differ in shape from module layer to module, the differences are slight, and the area is the same, so there is no variation in the ease of distinguishing module colors. Moreover, modules can be arranged without gaps in the module array area according to the present invention, just as in conventional matrix-type two-dimensional symbols. For this reason, the two-dimensional symbol of the present invention can have the same readability as conventional matrix-type two-dimensional symbols. Furthermore, since the modules are regularly arranged in a concentric or concentric arc shape within the module array region according to the present invention, the position of each module can be easily determined based on the center of the module array region and the rotation angle, etc. For this reason, the two-dimensional symbol of the present invention can determine the sampling position of the module's color with processing efficiency comparable to that of conventional matrix-type two-dimensional symbols. Furthermore, the two-dimensional symbol of the present invention has the advantage that the number of modules can be increased or decreased by increasing or decreasing the number of module layers that constitute the module array area, thus allowing for the easy generation of two-dimensional symbols with different numbers of modules depending on the amount of information to be recorded.

[0009] In the present invention, the module array region is composed of three or more module layers, and each module layer contains a predetermined number of modules greater than the number of modules in the module layer adjacent to it. If the module layer is annular in shape, the predetermined number is 6; if the module layer is a partial annular shape with a central angle of 180°, the predetermined number is 3; if the module layer is a partial annular shape with a central angle of 120°, the predetermined number is 2; and if the module layer is a partial annular shape with a central angle of 60°, the predetermined number is 1.

[0010] In this configuration, the length-to-width ratio of the module is approximately 1:1, making it possible to achieve color identification ease comparable to that of square-shaped modules such as QR codes.

[0011] In another aspect of the present invention, a two-dimensional symbol is proposed that records data by a module color scheme pattern, comprising a multilayer annular or multilayer sub-annular module array region in which a plurality of module layers, each consisting of circular modules arranged in a row at equal intervals in a circular or arc shape, are stacked in a concentric circular or concentric arc shape, wherein the modules included in the module array region are all the same size, and adjacent module layers in the inner and outer directions are arranged such that the circle or arc circumscribing each module in the inner module layer coincides with the circle or arc circumscribing each module in the outer module layer.

[0012] In this configuration, since the module array region is multi-layered annular or multi-layered sub-annular, the angularity of the two-dimensional symbol is reduced compared to conventional matrix-type two-dimensional symbols. In particular, in this configuration, since each module included in the module array region is circular, the angularity of the two-dimensional symbol can be further reduced, and the design quality can be further improved. Therefore, the two-dimensional symbol according to the present invention can be more harmoniously adapted to product packaging and advertisements that require a curved design. Each module arranged in the module array area according to the present invention is uniform in size and shape, so there is no variation in the ease of distinguishing the module's color. On the other hand, circular modules according to the present invention cannot be efficiently arranged within the module array area without creating gaps, so their area tends to be smaller than that of square modules. However, the peripheral part of a module contributes little to the ease of distinguishing the module's color, and for modules of the same area, the closer to a circle a module is, the higher the ease of distinguishing its color. Therefore, even if a circular module is slightly smaller than a square module, the ease of distinguishing its color does not significantly decrease. For this reason, the two-dimensional symbol according to the present invention can achieve the same information density and ease of distinguishing the color as a conventional matrix-type two-dimensional symbol. For this reason, the two-dimensional symbol according to the present invention can have the same readability as a conventional matrix-type two-dimensional symbol. Furthermore, since the modules are regularly arranged in a concentric or concentric arc shape within the module array region according to the present invention, the position of each module can be easily determined based on the center of the module array region and the rotation angle, etc. For this reason, the two-dimensional symbol of the present invention can determine the sampling position of the module's color with processing efficiency comparable to that of conventional matrix-type two-dimensional symbols. Furthermore, the two-dimensional symbol of the present invention has the advantage that the number of modules can be increased or decreased by increasing or decreasing the number of module layers that constitute the module array region, thus allowing for the easy generation of two-dimensional symbols with different numbers of modules depending on the capacity of the recorded information.

[0013] In the above invention, the module arrangement region is composed of three or more module layers, and each module layer contains a predetermined number of modules greater than the number of modules in the module layer adjacent to it. If the module layer arranges the modules in a circular shape, the predetermined number is 6; if the module layer arranges the modules in an arc shape with a central angle of approximately 180°, the predetermined number is 3; if the module layer arranges the modules in an arc shape with a central angle of approximately 120°, the predetermined number is 2; and if the module layer arranges the modules in an arc shape with a central angle of approximately 60°, the predetermined number is 1.

[0014] With this configuration, it becomes possible to reduce the gaps between modules while neatly arranging many modules in the module array area.

[0015] In the present invention, one code word is recorded by eight of the modules, and the eight modules constituting the code word are arranged in each code word recording layer, which consists of two layers of modules adjacent to each other in the inward and outward directions, and each code word recording layer is proposed to include a number of modules that is a multiple of eight.

[0016] In this configuration, since the modules that record codewords are arranged in units of codeword recording layers, the recording capacity of the module array area can be easily adjusted simply by increasing or decreasing the number of codeword recording layers arranged in the module array area. Furthermore, if the codeword recording layer is composed of two modules, the eight modules that record codewords can be densely arranged in two rows, making it easier to add error correction functionality. Also, if each codeword recording layer is composed of a multiple of eight modules, it becomes easier to arrange the modules that record codewords in the codeword recording layer.

[0017] In the present invention, the module array region comprises a plurality of module series sections in which the centers of the modules included in each module layer are arranged in a line in the radial direction, and the modules constituting two or more of the module series sections are colored according to a predetermined color scheme.

[0018] With this configuration, when reading a two-dimensional symbol, it becomes easier to correct the distortion of the two-dimensional symbol image based on the pattern of multiple module series sections contained in the captured two-dimensional symbol image. Furthermore, it becomes easier to determine the thickness of the module layer and the number of module layers based on the color scheme pattern of the module series sections.

[0019] In the present invention, each module is colored with one color selected from three or more reference colors, and a configuration is proposed in which sample areas are provided in two or more locations on the outer periphery of the module array area, each of which is colored with one of the three or more reference colors.

[0020] This configuration has the advantage of reducing errors in identifying the color of each module by using the color of each module in the sample area as a reference to identify the color of the module that records data. In other words, with the optical code of the present invention, errors in identifying the color of each module may increase due to changes in ink and paper over time, as well as the influence of printers, display devices, and ambient lighting, which may hinder the reading of the optical code. In this configuration, the color of each module in the sample area changes in the same way as the color of the module that records data due to changes in ink and paper over time, as well as the influence of printers, display devices, and ambient lighting. Therefore, when identifying the color of each module, by comparing it with the color of each module in the sample area, it is possible to eliminate changes over time and other influences and accurately identify which color each module is colored to. Also, if a plurality of sample areas are arranged in the module layer outside the module array area as in such a configuration, even if one sample area is damaged, the color of each module can be accurately identified based on other sample areas. In particular, since the outer module layer has the largest diameter, there is an advantage that it is easy to arrange the plurality of sample areas apart from each other so that they are not damaged simultaneously.

[0021] In the present invention, a configuration is proposed in which in the module layer arranged outside the module array area, management areas for recording information for specifying the number of the module layers constituting the module array area and / or the number of the modules included in the module layer are arranged at two or more locations in the color pattern of the modules.

[0022] In such a configuration, even if one management area is damaged, the information recorded in the module array area can be decoded based on the color pattern of the modules in other management areas. In particular, since the outer module layer has the largest diameter, there is an advantage that it is easy to arrange the plurality of management areas apart from each other so that they are not damaged simultaneously.

[0023] Another aspect of the present invention is a program for causing a computer to generate image data of the two-dimensional symbol.

[0024] Another aspect of the present invention is a program for causing a computer to read the recording data of the two-dimensional symbol according to any one of claims 1 to 8, the program causing the computer to execute a first step of imaging an image of the two-dimensional symbol, a second step of identifying the module array area in the image, a third step of determining the color pattern of the modules included in the module array area, and a fourth step of decoding the data recorded in the two-dimensional symbol based on the color pattern of the modules.

[0025] The present invention proposes a method for reading a two-dimensional symbol, comprising: an imaging step of capturing an image of the two-dimensional symbol; a color identification step of determining the color scheme of the modules in the module array region based on the image captured in the imaging step; and a decoding step of decoding the data recorded in the two-dimensional symbol based on the color scheme of the modules determined in the color identification step. [Effects of the Invention]

[0026] As described above, the present invention makes it possible to realize a two-dimensional symbol that is aesthetically pleasing and possesses the same readability as conventional two-dimensional symbols. [Brief explanation of the drawing]

[0027] [Figure 1] This is an example of a two-dimensional symbol 1 from Example 1. [Figure 2] This is an explanatory diagram showing the two-dimensional symbol 1 of Example 1 in terms of function. [Figure 3] This is an explanatory diagram showing the structure of module array region 4. [Figure 4] (A) A diagram showing the general outline of each module layer 3a to 3f. (B) A diagram showing the thickness and radius of module layer 3. (C) An explanatory diagram showing the length and width dimensions (thickness and width) of module 2. [Figure 5] This is an explanatory diagram showing the module array region 4 by function. [Figure 6] This is an explanatory diagram showing the structure of module array region 4a related to the modified form. [Figure 7] This is an example of a two-dimensional symbol 1a from Example 2. [Figure 8] This is an explanatory diagram showing the structure of the module array region 4b according to Example 2. [Figure 9] This diagram shows an overview of each module layer 30a to 30f. [Figure 10] This is an example of the two-dimensional symbol 1b in Example 3. [Figure 11] This is a diagram showing the correspondence between the reference color and the recorded data in Example 3. [Figure 12] This is an example of a two-dimensional symbol 1c from Example 4. [Modes for carrying out the invention]

[0028] Embodiments of the present invention will be described according to the following examples. [Examples]

[0029] Figure 1 is an example of the two-dimensional symbol 1 of this embodiment, and Figure 2 is an explanatory diagram showing the two-dimensional symbol 1 of this embodiment by function. The two-dimensional symbol 1 comprises a module array region 4 in which modules 2, which are colored in light (white) or dark (black), are arranged in a multi-layered ring shape. A circular internal region 5 is provided inside the module array region 4. The two-dimensional symbol 1 of this embodiment can be displayed on product packaging and advertisements for general consumers, and the internal region 5 can be used to display logos, explanations, etc. for general consumers. In this embodiment, a logo consisting of the letters "2DCode" is displayed. Outside the module array region 4, a position detection pattern 7 is provided to assist in the detection of the two-dimensional symbol 1 by a reader. The position detection pattern 7 has a dark ring shape and is provided so as to surround the module array region 4. In addition, a light-colored quiet zone 6 is provided outside the position detection pattern 7 to make the outer edge of the position detection pattern 7 identifiable.

[0030] Figure 3 is an explanatory diagram showing the structure of module array region 4. Module array region 4 is a multilayer annular structure divided into six module layers 3 by concentric circles at regular intervals, and each module layer 3 is further divided into multiple modules 2 by line segments extending in the radial direction. In other words, module array region 4 is composed of six annular module layers 3 (3a to 3f) arranged adjacently in a concentric circle. The thickness (difference between the outer radius and inner radius) of each module layer 3a to 3f is equal, and each module layer 3a to 3f is equally divided into multiple modules 2 (2a to 2f) by multiple line segments extending radially from the center of module layer 3a to 3f. Specifically, if we consider the module layers 3 as the first layer 3a, second layer 3b, third layer 3c, fourth layer 3d, fifth layer 3e, and sixth layer 3f from the inside out, the innermost first layer 3a is divided into 30 modules 2a by 30 line segments extending radially from the center of the module array region 4 at angles of π / 15 (12°). The second layer 3b is divided into 36 modules 2b by 36 line segments extending at angles of π / 18 (10°). Similarly, the third layer 3c is divided into 42 modules 2c, the fourth layer 3d into 48 modules 2d, the fifth layer 3e into 54 modules 2e, and the sixth layer 3f into 60 modules 2f.

[0031] In this embodiment, module layers 3a to 3f are divided without gaps so that all modules 2a to 2f have the same area. Specifically, in this embodiment, as described above, each module layer 3 is divided such that the number of modules 2 is 6 more than the adjacent module layer 3 inside it. In this way, when increasing the number of modules 2 contained in each module layer from the inner module layer 3 to the outer module layer by a fixed number, all module layers 3a to 3f can be divided into modules 2a to 2f of equal area by setting the radius (average of outer and inner radii) and thickness (difference between outer and inner radii) of module layer 3 to an appropriate ratio. More specifically, if the number of modules in the first layer 3a is k, and the number of modules in the second layer 3b and subsequent layers is increased by n each time (k+n, k+2n, ..., k+5n), then if the radius r of the first layer 3a and the thickness t of each module layer 3 are set in a ratio that satisfies r:t=k:n, then all module layers 3a to 3b will be equally divided into modules 2a to 2f of the same area without any gaps. In the two-dimensional symbol 1 of this embodiment, k=30 (modules) and n=6 (modules), so as shown in Figures 4(A) and 4(B), the radius r of the first layer 3a is set to 5 times the thickness t of the module layer 3 (5t), thereby making the area of ​​each module 2 equal. Note that once the radius and thickness of the first layer 3a are determined, the radii of the second layer 3b to the sixth layer 3f are uniquely determined.

[0032] Figure 4(A) shows the specifications of each module layer 3a to 3f and each module 2a to 2f. As described above, all modules 2a to 2f are partial annular shapes obtained by dividing the annular module layer 3a to 3f. The outer module layers 3a to 3f have a larger area, but by increasing the number of modules 2a to 2f for the outer module layers 3a to 3f, all module layers 3a to 3f are divided into modules 2a to 2f of the same area. As shown in Figure 4(A), the shapes of modules 2a to 2f in each module layer 3a to 3f are not significantly different, although the curvature of the inner and outer arcs differs slightly, and are comparable to squares of the same area. Thus, in this embodiment, the modules 2a to 2f constituting each module layer 3a to 3f have the same area and, although their shapes differ slightly, are substantially the same, so the ease of distinguishing the colors of modules 2a to 2f does not vary depending on the module layer 3a to 3f.

[0033] Thus, the two-dimensional symbol 1 of this embodiment has a multi-layered annular structure for its module arrangement area 4, resulting in a less angular and more aesthetically pleasing design compared to conventional matrix-type two-dimensional symbols where modules are arranged in a grid pattern. For this reason, the two-dimensional symbol 1 of this embodiment is suitable for display on product packaging, flyers, posters, websites, and other applications where a curved design is required. Furthermore, the multi-layered annular structure for the module arrangement area 4 offers the advantage of allowing the display of a logo or explanatory text for general consumers in the inner area 5 within the module arrangement area 4, as in this embodiment.

[0034] Furthermore, since each module 2a to 2f in this embodiment has substantially the same shape and the same area, each module 2a to 2f from the inner first layer 3a to the outer sixth layer 3f has uniform color identifiability. And because these modules 2a to 2f are arranged without gaps in the module array region 4, the two-dimensional symbol of this embodiment can have the same readability as a conventional matrix-type two-dimensional symbol.

[0035] In particular, in this embodiment, the number of modules 2 contained within the outer module layer 3 is 6 more than the number of modules 3 adjacent to each other both inside and outside. With this configuration, as shown in Figures 4(A) and 4(C), the width of each module 2 (the average of the outer and inner arc lengths) is always "π / 3 times (approximately 1.05 times)" the vertical width of each module 2 (the thickness of the module layer 3), and the aspect ratio of the module 2 is approximately 1:1. As a result, a shape is obtained that is comparable in terms of color discrimination ease to that of a square module of a matrix-type two-dimensional symbol.

[0036] As shown in Figures 1 and 2, the position detection pattern 7 has a dark, annular shape and is arranged concentrically so as to be in contact with the outside of the module array region 4. The position detection pattern 7 has a thickness 1.5 times that of the module layers 3a to 3f, and an angle mark 11 for detecting the rotation angle is provided at the bottom of the position detection pattern 7. The angle mark 11 is formed by cutting out the dark, annular shape of the position detection pattern 7 in a light color. As described above, a light-colored quiet zone 6 is provided outside the position detection pattern 7, so when reading the two-dimensional symbol 1, the annular shape of the position detection pattern 7 and the angle mark 11 can be identified, making it relatively easy to determine the center of the module array region 4 and the rotation angle.

[0037] The position detection pattern 7 is not limited to the shape and arrangement of this embodiment; any shape and arrangement that allows for easy identification of the center and rotation angle of the module array region 4 is acceptable. For example, the position detection pattern may be placed at a position spaced apart from the module array region 4. Alternatively, the position detection pattern may be placed adjacent to the module array region 4. Furthermore, the position detection pattern may be placed in part or all of the internal region 5. In addition, the module 2 at a specific position in the module array region 4 may be colored in a predetermined pattern to incorporate the function of a position detection pattern into the module array region 4. For example, if all but one module 2a of the first layer 3a of the module array region 4 in this embodiment are colored in a dark color to create a cut-out dark annular shape, the first layer 3a can be made to function as a position detection pattern.

[0038] As shown in Figures 1 and 3, the module array area 4 of this embodiment has 270 modules 2 arranged in it, and each module 270 is colored either light (white) or dark (black). Here, the module array area 4 is broadly divided into a fixed area where the coloring of the modules 2 is fixed, and a variable area where the coloring of the modules 2 changes depending on the recorded information, etc. Specifically, in Figure 5, the parts shown in white or dark are the fixed areas, and the parts shown in other shaded areas are the variable areas.

[0039] The fixed area is intended to assist in reading the two-dimensional symbol 1. In Figure 5, the areas shown in white or dark are the fixed areas, and the module 2 in the areas shown in white is always colored white, while the module 2 in the areas shown in black is always colored black. Here, the module array area 4 includes a module series section 13 in which the centers of modules 2a to 2f included in the six module layers 3a to 3f are arranged in a line in the radial direction. Specifically, in Figure 5, the module series section 13 consists of six rows of modules 2a to 2f arranged on straight lines extending radially at ±30°, ±90°, and ±150° from the center of the module array area 4. The modules 2a to 2f in this module series section 13 are arranged more regularly than the other modules 2a to 2f, making it relatively easy to identify their positions. Therefore, many of the modules 2a to 2f constituting the module series section 13 are included in the fixed area. For example, in Figure 5, the modules 2 of the two vertically aligned module series section 13 form a timing pattern 9 with alternating light and dark colors. This timing pattern 9 makes it easy to identify the number of layers and thickness of module layers 3a to 3f, and can also be used to correct distortion of the two-dimensional symbol 1.

[0040] The variable area is used to record data according to the color scheme pattern of Module 2. The variable area is divided into unit recording areas, each consisting of eight Module 2 units. In Figure 5, the areas separated by diagonal lines represent the individual unit recording areas 14a and 14b. Unit recording area 14a consists of a management area 14a and a code word recording area 14b.

[0041] The management area 14a records information regarding the specifications of the module array area 4. Specifically, the specifications of the module array area 4 include the number of module layers 3 and the number of modules 2 included in each module layer 3. With this configuration, even if there are multiple types of two-dimensional symbols with different specifications for the module array area 4, the specifications of the module array area 4 can be identified based on the recorded information in the management area 14a, which can be used to read the two-dimensional symbol 1. As shown in Figure 5, the management area 14a is composed of two unit recording areas. To prevent the management area information from becoming unreadable due to contamination or other reasons, the same information is duplicated in each of these unit recording areas 14a and they are arranged spaced apart from each other on the outer periphery of the module array area 4.

[0042] The codeword recording area 14b stores codewords, each consisting of 8 bits. Of the unit recording areas 14a and 14b in the variable area, 26 are designated as codeword recording areas 14b, excluding the management area 14a. In other words, 26 codewords are recorded in the variable area. The codeword consists of a data codeword for recording data and an error correction codeword for correcting errors in the data codeword. The error correction codeword is Reed-Solomon coding, with one codeword (8 bits) corresponding to one Reed-Solomon symbol. The encoding method for data codewords and the generation method for error correction codewords can be adapted from standards such as the QR code standard (JIS X 0510:2018).

[0043] The eight modules 2, each recording a single code word, are arranged in two rows on two adjacent module layers 3, one inward and the other outward. This is because each code word corresponds to one symbol in Reed-Solomon coding (error correction coding), and due to the characteristics of Reed-Solomon coding, which excels at correcting burst errors, arranging the eight modules 2 in a clustered manner improves error correction functionality compared to dispersing them or arranging them in a long, narrow row.

[0044] In particular, this embodiment provides a codeword recording layer in which unit recording areas 14a and 14b are arranged, with two adjacent module layers 3 located inside and outside the module layer forming a set. Specifically, the first layer 3a and the second layer 3b are designated as the first codeword recording layer, and seven unit recording areas 14a are arranged in the first codeword recording layer. The third layer 3c and the fourth layer 3d are designated as the second codeword recording layer, and nine unit recording areas 14a are arranged in the second codeword recording layer. The fifth layer 3e and the sixth layer 3f are designated as the third codeword recording layer, and twelve unit recording areas 14a and 14b are arranged in the third codeword recording layer.

[0045] In this way, by arranging the codeword recording area 14b to fit within a codeword recording layer consisting of two adjacent module layers 3, one inside and one outside, it is possible to easily create module array areas with different numbers of module layers 3 depending on the amount of information recorded by the two-dimensional symbol. For example, by removing the first layer 3a and the second layer 3b (the first codeword recording layer) from the module array area 4, a four-layer module array area consisting of the third layer 3c to the sixth layer 3f can be created. In this case, since the codeword recording areas 14b from the third layer 3c to the sixth layer 3f do not span the first layer 3a and the second layer 3b, the partitions of the codeword recording areas 14b from the third layer 3c to the sixth layer 3f can be reused without modification. Similarly, by adding the seventh and eighth layer module layers 3 (the fourth codeword recording layer) outside the module array area 4, an eight-layer module array area can be created. Even in this case, the partitions of the codeword recording areas 14b from the first layer 3a to the sixth layer 3f can be reused without modification.

[0046] The image data of the two-dimensional symbol 1 in this embodiment can be generated, for example, by having the computer execute the following steps (1) to (10) using a dedicated generation program installed on the computer. (1) Information to be recorded in the two-dimensional symbol 1 and an image to be displayed in the internal region 5 are acquired. (2) The specifications of module array area 4 (number of layers in module layer 3 and number of modules 2) are determined according to the size of the information. (3) The information is encoded into a data codeword, and an error correction codeword corresponding to the encoded data codeword is generated. (4) Based on the specifications of module array area 4, the data codeword, and the error correction codeword, the color scheme pattern of each module 2 in module array area 4 is determined. (5) The color scheme of each module 2 in the module array region 4, the position detection pattern 7, and the display image in the internal region 5 are combined to generate an image of the two-dimensional symbol 1.

[0047] The two-dimensional symbol 1 of this embodiment can be read, for example, by using a dedicated reading program installed on a mobile terminal (computer) and causing the mobile terminal to perform the following steps (1) to (10). Furthermore, step (1) corresponds to the imaging step according to the present invention, steps (2) to (9) correspond to the color identification step according to the present invention, and step (10) corresponds to the composite step according to the present invention. Also, step (1) corresponds to the first step according to the present invention, steps (2) to (8) correspond to the second step according to the present invention, step (9) corresponds to the third step according to the present invention, and step (10) corresponds to the fourth step according to the present invention. (1) Capture an image of the two-dimensional symbol 1 using the imaging function of the mobile device. (2) The position detection pattern 7 is detected from the captured image. Specifically, the elliptical shape of the outer edge of the position detection pattern 7 (the boundary with the quiet zone 6) is detected. (3) The two-dimensional symbol 1 of the captured image will not be a perfect circle unless it is captured from directly in front, but will be approximately elliptical in shape. For this reason, the image is corrected so that the module array region 4 becomes a perfect circle, so that the elliptical shape of the outer edge of the position detection pattern 7 detected in the previous step becomes a perfect circle. (4) Based on the image position detection pattern 7 corrected in the previous step, the center coordinates of the module array region 4 are determined. (5) Identify the angle marks 11 of the position detection pattern 7 to determine the rotation angle and rotate the image while maintaining the center coordinates. (6) The module series section 13 is scanned along its center to extract the light and dark patterns of the pixels, and the degree of image distortion is detected from the intervals between the detected light and dark patterns. If necessary, the detected image distortion is corrected. (7) Based on the scanning results from the previous step, the outer diameter of the module array region 4 and the thickness of the module layer 3 are determined. Then, based on the determined outer diameter of the module array region 4 and the thickness of the module layer 3, the sampling coordinates of the module 2 in the management region 14a located on the outer periphery are determined. As described above, in this embodiment, the radius and thickness of the module layer 3 are set in an appropriate ratio in order to divide each module layer 3 into modules 2 of the same area. Therefore, if the outer diameter of the module array region 4 and the thickness of the module layer 3 can be determined, it is possible to calculate how many modules 2 the outer periphery module layer 3 is divided into. (8) Identify the color of module 2 in management area 14a, determine the specifications of module array area 4 recorded in management area 14a (number of layers of module layer 3), and determine the sampling coordinates of all module 2 in code word recording area 14b. The sampling coordinates of each module 2 can be easily determined in a polar coordinate system centered on the central coordinate of module array area 4. (9) Determine the color of module 2 in code word area 14b. (10) Based on the color of module 2 in code word area 14b, the recorded information of the two-dimensional symbol 1 is decoded.

[0048] As described above, the two-dimensional symbol 1 of this embodiment allows for easy identification of the colors of module 2, similar to conventional matrix-type two-dimensional symbols. Therefore, the information recorded on the two-dimensional symbol 1 can be easily read using the reading method described above. Furthermore, in the two-dimensional symbol 1 of this embodiment, since modules 2 are arranged at regular intervals on concentric circles, if an image of the two-dimensional symbol 1 is captured and the center position and rotation angle of the module arrangement region 4 can be determined using the reading method described above, the position of module 2 can be determined based on the center position and rotation angle, and the color of each module 2 can be easily determined. For this reason, the two-dimensional symbol 1 of this embodiment can be read at a speed comparable to that of conventional matrix-type two-dimensional symbols using the reading method described above.

[0049] Furthermore, the two-dimensional symbol 1 of this embodiment forms a multilayer annular structure divided into multiple module layers 3, and each module layer 3 is divided into multiple modules 2 by radially extending line segments. Therefore, by increasing or decreasing the number of module layers 3 constituting the module array region 4 and the number of modules 2 contained within each module layer 3, two-dimensional symbols with different numbers of modules can be easily generated according to the capacity of the recorded information. That is, the module array region 4 of this embodiment is divided into six module layers 3 and equally divided into 270 modules 2 of the same area, but the number of module layers 3 only needs to be three or more, and the number of modules 2 contained within each module layer 3 can also be changed as appropriate. For example, Figure 6 shows a modified module array region 4a from Embodiment 1 in which the number of module layers 3 and the number of modules 2 have been changed. This module array region 4a forms a multilayer annular structure consisting of eight module layers 3 of the same thickness. The first module layer 3 from the inside is equally divided into nine modules 2 by radially extending line segments. Furthermore, the number of modules 2 contained in each module layer 3 increases by 6 from the inside outwards: 9 → 15 → 21 → ... → 51. Even when arranging modules 2 in this way, as mentioned above, if the radius r of the innermost module layer 3 and the thickness t of each module layer 3 are set to a ratio satisfying r:t = 9:6, then all module layers 3 can be equally divided into modules 2 of the same area, as shown in Figure 6. Also, in this modified example, for adjacent module layers 3 inside and outside, the outer module layer 3 has 6 more modules 2 in each direction, so the aspect ratio of the modules 2 is approximately 1:1, achieving the same ease of color identification as the square modules of a matrix-type two-dimensional symbol. In this embodiment, since the module layers 3 are arranged up to near the center of the module arrangement area 4a, the internal area 5 is not provided. If there is no need to display a logo or explanatory text in the internal area 5, then arranging the module layers 3 up to near the center of the module arrangement area 4a, as in this embodiment, allows for efficient arrangement of modules 2. Furthermore, in this modified version, the first and second layers, the third and fourth layers, the fifth and sixth layers, and the seventh and eighth layers are paired together to form four sets of code word recording layers.In this configuration, the number of Module 2s included in each codeword recording layer is always a multiple of 8, which has the advantage of making it easy to arrange unit recording areas, each consisting of 8 Module 2s, to fit within each codeword recording layer. [Examples]

[0050] This embodiment is a modification of Embodiment 1 in which the module shape is changed. Specifically, in Embodiment 1, partially annular modules 2 are arranged without gaps in the module array region 4, whereas in this embodiment, as shown in Figure 7, circular modules 20 are arranged in the module array region 4b, with gaps 16 provided between modules 20. Note that the internal region 5 and position detection pattern 7 are the same as in Embodiment 1, so they are given the same reference numerals and their description is omitted.

[0051] Figure 8 is an explanatory diagram showing the structure of the module array region 4b according to this embodiment. Although the shape of the modules 20 differs, the module array region 4b according to this embodiment consists of six module layers 30, similar to Embodiment 1, and modules 20 are arranged in the same positions in each module layer 30 as in Embodiment 1. More specifically, the module array region 4b is a multilayer annular structure formed by stacking six annular module layers 30 (30a to 30f), each consisting of circular modules 20 arranged in a circular line at equal intervals, in a concentric arrangement. All modules 20 are uniform in size. As shown in Figure 8, the thickness of each module layer 30 (difference between the outer radius and the inner radius) is equal to the diameter of the module 20, and each module 20 is in contact with the outer and inner edges of the module layer 30. Adjacent module layers 30 are arranged such that the circle circumscribing each module 20 of the inner module layer 30 coincides with the circle inscribed in each module 20 of the outer module layer 30.

[0052] The ratio of radius to thickness of the six module layers 30 is set to be the same as that of the six module layers 3a to 3f in Example 1. Then, the same number of modules 20 as in Example 1 are arranged at equal intervals in each module layer 30. That is, if the module layers 30 are numbered from the inside out as the first layer 30a, the second layer 30b, the third layer 30c, the fourth layer 30d, the fifth layer 30e, and the sixth layer 30f, then in the innermost first layer 30a, modules 20 are arranged at angles of π / 15 (12°) with respect to the center of the module arrangement region 4. Similarly, in the second layer 30b, modules 20 are arranged at angles of π / 18 (10°). In the same way, 42 modules 20 are arranged in the third layer 30c, 48 modules 20 are arranged in the fourth layer 30d, 54 modules 20 are arranged in the fifth layer 30e, and 60 modules 20 are arranged in the sixth layer 30f. In this way, by arranging the circular modules 20 in the same manner as in Example 1, the gaps 16 between the modules 20 can be narrowed, and at the same time, the modules 20 can be arranged in an orderly manner in the module arrangement region 4b.

[0053] In each module layer 30, the gaps 16 between modules 20 are colored gray, an intermediate color. This is to minimize the difference in the influence of the color of the gaps 16 on light-colored (white) modules 20 and dark-colored (black) modules 20, so that modules 20 of either color can be distinguished with the same degree of accuracy. Note that the gaps 16 may also be colored with a color other than gray.

[0054] Figure 9 shows the specifications of each module layer 30a to 30f and module 20. As described above, all modules 20 are circular in shape with a diameter equal to the thickness of module layer 30. The outer module layers 30a to 30f have a larger area, but by increasing the number of modules 20 placed in each module layer 30a to 30f by 6 from the inside outwards, modules 20 are placed at approximately uniform intervals in all 30a to 30f. The lower part of the diagram in Figure 9 compares the shape and size of modules 2a to 2f and 20 when the module arrangement areas 4 and 4b of this embodiment and Embodiment 1 are made the same size. As shown in Figure 9, the module 20 of this embodiment has the shape and size of modules 2a to 2f of Embodiment 1 with the four corners of the periphery cut off, and the area per module is 3 / 4 of that of Embodiment 1. Thus, in this embodiment, module 20 is relatively smaller than in Embodiment 1. However, as shown in Figure 9, the difference in size between modules 2a-2f and 20 is due to the presence or absence of sharp corners on modules 2a-2f. Therefore, the ease of color identification is not significantly inferior to that of Embodiment 1. This is because the peripheral areas of modules 2a-2f and 20 contribute little to the ease of color identification, and the presence or absence of corners on modules 2a-2f does not significantly change the ease of color identification.

[0055] Thus, in the two-dimensional symbol 1a of this embodiment, not only is the module array region 4b circular, but each module 20 is also circular, completely eliminating the angularity of the module array region 4. Therefore, the design quality can be improved compared to the two-dimensional symbol 1 of Embodiment 1. For this reason, the two-dimensional symbol 1 of this embodiment can be more harmoniously matched with product packaging and advertisements that require a curved design.

[0056] Furthermore, since the modules 20 in this embodiment are uniform in size and shape, there is no variation in the ease of color identification. Although there are gaps 16 between modules 20 in this embodiment, circular modules 20 have superior color identification capabilities compared to angular square modules, so even if the size is slightly smaller, the ease of color identification is not significantly inferior. For this reason, the two-dimensional symbol 1a in this embodiment can achieve readability equivalent to that of conventional matrix-type two-dimensional symbols.

[0057] In this embodiment, although the shape of the module 20 differs, the arrangement of the module 20 is the same as in Embodiment 1. Therefore, an image of the two-dimensional symbol 1a can be generated using the same generation method (generation program) as in Embodiment 1, and the recorded information of the two-dimensional symbol 1a can be read using the same reading method (reading program) as in Embodiment 1. [Examples]

[0058] This embodiment is a modification of the configuration of Embodiment 1. Specifically, while module 2 in Embodiment 1 is colored in either a light color (white) or a dark color (black), in the two-dimensional symbol 1b of this embodiment, as shown in Figure 10, module 21 is colored in one color selected from eight standard colors. Note that the configuration of module 21 other than the color scheme is the same as in Embodiment 1, so the same reference numerals are used in the figure and their explanation is omitted.

[0059] More specifically, as shown in Figure 11, in this embodiment, "white," "yellow," "blue-green," "green," "purple," "red," "blue," and "black" are set as reference colors, and each module 21 is selectively colored with one of these reference colors. Then, 3 bits of data are recorded depending on which reference color is used. In this way, in this embodiment, 3 bits of data can be recorded in one module 21, so approximately three times the amount of data can be recorded compared to the two-dimensional symbol 1 of Embodiment 1. In addition, the range of colors in the module array area 4c is also richer, improving the design compared to Embodiment 1.

[0060] The module array region 4c in this embodiment is composed of a fixed region and a variable region, similar to the module array region 4 in Embodiment 1. The variable region is divided into unit recording regions 14a, 14b, and 14c, each consisting of eight modules 2 (see Figure 5). As shown in Figure 5, in this embodiment, a sample region 14c is provided in the unit recording region on the outer periphery of the module array region 4c to identify which reference color each module 2 corresponds to. In Embodiment 1, these unit recording regions constitute the code word recording region 14b. The sample region 14c is a region in which the eight modules 21 constituting the unit recording region are each colored with one of eight different reference colors. It is predetermined which module 21 in the sample region 14c will be colored with which reference color. To prevent the reference colors from becoming difficult to identify due to contamination, the sample region 14c is triple-layered in three unit recording regions spaced apart from each other on the outer periphery of the module array region 4c. Thus, since each module 21 contained in the sample area 14c is always colored with a defined reference color, when reading the two-dimensional symbol 1b, the reader can accurately identify which reference color the module 21 in the code word recording area 14b is by comparing it with the color of the module 21 in the sample area 14c. In other words, when identifying the reference color of each module 21 from the RGB values ​​of the image data of the two-dimensional symbol 1b, there is a high possibility of errors in identifying the reference color due to changes in ink over time and the imaging environment. However, in this configuration, by determining the reference color by comparing it with the module 21 in the sample area 14c, the influence of changes in ink over time and the imaging environment can be eliminated, and thus errors in identifying the reference color can be reduced.

[0061] In this embodiment, similar to Embodiment 1, information regarding the specifications of the module array area 4c is recorded in the management area 14a. Here, the information recorded in the management area 14a also includes information regarding the reference colors. That is, when reading the two-dimensional symbol 1b, it is possible to determine how many types of reference colors are used to color the module 21 based on the information in the management area 14b. As shown in Figure 11, in this embodiment, four of the eight types of reference colors are relatively bright colors, and the remaining four are relatively dark colors. The information in the management area 14a is recorded as a binary pattern of light and dark, consisting of four light reference colors and four dark reference colors. This is because, if there are multiple types of two-dimensional symbols with different numbers of reference colors, it is not possible to determine how many types of reference colors are used to color each module 21 until the information in the management area 14a has been read. On the other hand, if the module 21 in the management area 14a is colored with only two colors, white and black, the color balance with the other unit recording areas 14b and 14c will be disrupted, impairing the design aesthetics. Furthermore, in this embodiment, each module 21 constituting the fixed area is also colored as a binary pattern of light and dark, using four types of light reference colors and four types of dark reference colors, rather than just white and black, for the same reasons as the management area 14a.

[0062] As in this embodiment, by coloring the module array area 4 with three or more colors, it is possible to improve the design and simultaneously improve the recording density compared to the monochrome two-dimensional symbol 1 of Embodiment 1. In this embodiment, the module 21 is selectively colored with eight colors, but the module 21 may also be colored with four or sixteen colors. The position detection pattern 7 may also be colored with a color other than black. Furthermore, for the two-dimensional symbol 1a of Embodiment 2, the module 20 may also be selectively colored with one color selected from three or more reference colors, as in this embodiment. [Examples]

[0063] As shown in Figure 12, the two-dimensional symbol 1c of this embodiment has a module array region 4d that forms a multilayered sub-annular shape. Specifically, the multilayered annular module array region 4 of Embodiment 1 is divided into 1 / 3 sections along a straight line with a central angle of 120° that extends radially. That is, the module array region 4d has a shape in which six module layers 31, each forming a sub-annular shape with a central angle of 120°, are arranged adjacent to each other in a concentric arc. The shape of the module 2 is the same as in Embodiment 1, and each module layer 31 contains 1 / 3 the number of modules 2 as in Embodiment 1. That is, each module layer 3 has 10, 12, 14, 16, 18, and 20 modules 2 arranged in order from the inside, with the number of modules 2 increasing by 2 from the inside to the outside. Outside the module array region 4c, a position detection pattern 7a, which is divided into 1 / 3 sections similar to the module array region 4c, is placed adjacent to it, and the characters "2DCode" are displayed in the internal region 5a inside the module array region 4c, similar to Example 1.

[0064] Thus, the two-dimensional symbol of the present invention is not limited to a multilayer annular shape, but may also be a multilayer sub-annular shape. Even with such a configuration, the outer edge of the module array region 4c is arc-shaped, resulting in excellent design aesthetics, and since the shape of each module 2 is the same as in Example 1, it can be made easily readable, similar to a matrix-type two-dimensional symbol. In this embodiment, the module array region 4c has a shape obtained by dividing a multilayer annular shape into 1 / 3, but it is also possible to make a multilayer sub-annular shape obtained by dividing the multilayer annular shape into 1 / 2 (central angle 180°) or 1 / 6 (central angle 60°). When making a multilayer sub-annular shape obtained by dividing the module array region into 1 / 2, the number of modules 2 should be increased by 3 sequentially from the inner module layer, and when making a multilayer sub-annular shape obtained by dividing it into 1 / 6, the number of modules 2 should be increased by 1 sequentially from the inner module layer. Furthermore, for the two-dimensional symbol 1a in Example 2 and the two-dimensional symbol 1b in Example 3, it is also possible to change the module array regions 4b and 4c to multilayer sub-annular structures, as in this embodiment.

[0065] Although embodiments of the present invention have been described above, the configuration of the embodiments of the present invention can be appropriately modified without departing from the spirit of the invention. For example, the shape and arrangement of the position detection pattern, the color of the module, the data encoding method and error correction method can be appropriately modified in the embodiments. Furthermore, the two-dimensional symbol according to the present invention only needs to have the module array area according to the present invention, and modules may be arranged in areas other than the module array area according to the present invention. Also, in the above embodiment, a fixed area and a management area 14a are provided in the module array area 4, but if there is only one type of configuration of the module array area 4 (number of layers of module layer 3 and number of divisions of module 2), the entire module array area 4 may be used as the code word recording area 14b. Furthermore, the two-dimensional symbol of the present invention is suitable for display on objects and screens that are visible to general consumers, such as product packaging and advertisements, but this does not exclude its use in production sites and logistics sites. [Explanation of symbols]

[0066] 1,1a~1c Two-dimensional symbols Modules 2, 2a~2f, 20, 21 Module layers 3, 3a~3f, 30, 30a~30f, 31 4,4a~4d Module array region 5,5a internal area 6. Quiet Zone 7,7a Position detection pattern 9 Timing Patterns 11 Angle Mark 13. Module series section 14a Management area (unit recording area) 14b Code word recording area (unit recording area) 14c Sample area (unit recording area) 16 gaps

Claims

1. A two-dimensional symbol that records data using the module's color scheme pattern, The module array region comprises a multilayer annular or multilayer sub-annular module array region in which multiple module layers having an annular or partially annular shape are arranged adjacently in a concentric or concentric arc pattern, A two-dimensional symbol characterized in that all of the module layers constituting the module array region have the same thickness and are equally divided into modules of the same area by line segments extending in the radial direction of the module layer.

2. The aforementioned module array region is composed of three or more of the aforementioned module layers. Each of the above module layers contains a predetermined number of modules in addition to the module layers adjacent to it. If the module layer is annular in shape, the predetermined number is six. If the module layer has a partial annular shape with a central angle of 180°, the predetermined number is 3. If the module layer has a partial annular shape with a central angle of 120°, the predetermined number is 2. The two-dimensional symbol according to claim 1, characterized in that if the module layer has a partial annular shape with a central angle of 60°, the predetermined number is 1.

3. A two-dimensional symbol that records data using the module's color scheme pattern, The module array region comprises a multilayer annular or multilayer subannular module array area in which multiple module layers, each consisting of circular modules arranged in a circular or arc shape at equal intervals, are stacked in a concentric circular or concentric arc shape. The modules included in the module array region are all the same size. The adjacent module layers in the inward and outward directions are arranged such that the circle or arc circumscribing each module of the inner module layer coincides with the circle or arc inscribed in each module of the outer module layer. The aforementioned module array region is composed of three or more of the aforementioned module layers. Each of the above module layers contains a predetermined number of modules in addition to the module layers adjacent to it. If the module layer is an arrangement of modules in a circular shape, the predetermined number is 6. If the module layer is arranged in an arc shape with a central angle of approximately 180°, then the predetermined number is 3. If the module layer is arranged in an arc shape with a central angle of approximately 120°, then the predetermined number is 2. A two-dimensional symbol characterized in that, if the module layer is arranged in an arc shape with a central angle of approximately 60°, the predetermined number is 1.

4. The eight aforementioned modules record one code word. The eight modules constituting the codeword are arranged in each codeword recording layer, which consists of two adjacent module layers in the inward and outward directions. The two-dimensional symbol according to any one of claims 1 to 3, characterized in that each of the codeword recording layers includes a number of modules that is a multiple of 8.

5. The module array region comprises a plurality of module series sections in which the centers of the modules included in each module layer are arranged in a line in the radial direction. The two-dimensional symbol according to any one of claims 1 to 4, characterized in that the modules constituting the series section of two or more modules are colored according to a predetermined color scheme.

6. Each of the aforementioned modules is colored with one color selected from three or more standard colors. The two-dimensional symbol according to any one of claims 1 to 5, characterized in that two or more sample areas are provided on the outer periphery of the module array area, in which the modules at predetermined positions are each colored with the three or more reference colors.

7. The two-dimensional symbol according to any one of claims 1 to 6, characterized in that the module layer, which is located outside the module array region, has two or more management areas provided for recording information for identifying the number of module layers constituting the module array region and / or the number of modules included in the module layer, using the module's color scheme pattern.

8. A program for causing a computer to generate image data of a two-dimensional symbol according to any one of claims 1 to 7.

9. A program for causing a computer to read recording data of a two-dimensional symbol as described in any one of claims 1 to 7, to the computer A first step of capturing an image of the aforementioned two-dimensional symbol, A second step involves identifying the module array region in the image and determining the color sampling position of the module in the image based on the arrangement pattern of the modules of the two-dimensional symbol, A third step is to determine the color scheme of the modules included in the module array region, A fourth step involves decoding the data recorded in the two-dimensional symbol based on the color scheme of the module. A program to execute.

10. A method for reading a two-dimensional symbol according to any one of claims 1 to 7, The imaging step involves capturing an image of the aforementioned two-dimensional symbol, A color identification step that identifies the sampling position of the color of the module in the image and determines the color scheme of the module in the module array region, based on the image captured in the imaging step and the arrangement pattern of the module of the two-dimensional symbol. A decoding step is performed to decode the data recorded in the two-dimensional symbol based on the color scheme of the module determined in the color identification step. A method for reading a two-dimensional symbol, characterized by including [a certain element].

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