JP2014154118A - Optical code and generation method for the optical code - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical code that has a recording density higher than a monochrome optical code while retaining compatibility with a standard conventional monochrome optical code.SOLUTION: Colors are assigned to modules for an optical code so as to be distinguished from one of reference colors of two or more of types. The reference colors of two or more types are composed of a plurality of bright reference colors equal to or higher than a predetermined bright color threshold in reflectance or brightness, and a plurality of dark reference colors equal to or lower than a predetermined dark color threshold in reflectance or brightness. One of the bright reference colors is assigned to a module distinguished as a bright color, such that the module can be distinguished. One of the dark reference colors is assigned to a module distinguished as a dark color, such that the module can be distinguished. Thereby, two types of data are recorded, one of which is general-purpose data recorded according to information indicating which one of a bright reference color and dark reference color each module has, and the other of which is exclusive data recorded according to information indicating which type of the bright reference color or dark reference color each module has.

Description

  The present invention relates to an optical code composed of a plurality of modules.

  Optical codes such as barcodes and two-dimensional codes, which are currently popular, record information by assigning white or black to a module as a basic unit. Standards for such black and white optical codes are standardized, and any standardized optical code can be read by a reading device such as a mobile phone so that anyone can know the recorded contents. .

  While the standardized black and white optical code is excellent in versatility, it has a drawback that it is difficult to increase the amount of information. For this reason, as a means for increasing the recording density, a configuration has been proposed in which data of more than 1 bit can be recorded in one module by arranging each module with various colors (for example, Patent Document 1). ).

JP 2010-61217 A

  The optical code described in Patent Document 1 has a larger number of module colors and a different method for encoding data compared to an existing monochrome optical code. It cannot be read by a reader for reading the code. Therefore, if the optical code described in Patent Document 1 is adopted as a new standard in place of the standardized black and white optical code, it is necessary to change the software and hardware of the black and white optical code reading device. .

  However, standardized black-and-white optical codes such as commodity barcodes and QR codes (registered trademark) are very widespread, and there are a large number of reading devices for reading these optical codes. It is difficult to change all the devices according to the new standard optical code. In order to be able to read information even with a black and white optical code reader, it is proposed to display the current standard black and white optical code in parallel with the new standard optical code, but it is necessary to widen the optical code printing space. In other words, the original purpose of increasing the recording density cannot be achieved.

  The present invention has been made in view of the present situation, and an object of the present invention is to provide an optical code capable of increasing the recording density while maintaining compatibility with a standardized conventional monochrome optical code.

  The present invention is an optical code configured by modules identified as light or dark colors, and each module is color-coded so as to be identified as one of a plurality of types of reference colors having different RGB values. The type of reference color is composed of a plurality of light color reference colors whose reflectance or luminance is equal to or higher than a predetermined light color threshold value, and a plurality of dark color reference colors whose reflectance or luminance is equal to or lower than a predetermined dark color threshold value. The modules identified with the light color reference color are identifiable with one of the light color reference colors, the modules identified with the dark color are identifiable with one of the dark color reference colors, and each module has a light color reference color. And the general-purpose data recorded by the information on whether the reference color is the dark color reference color, and the special data recorded by the information on which type of reference color the light color reference color or the dark color reference color is used for each module. An optical code characterized in that it comprises at least two kinds of data with the data.

  When such an optical code is read by an existing reader, a module arranged in a light color reference color (hereinafter referred to as a light color module) is identified as a light color and is arranged in a dark color reference color (hereinafter referred to as a light color reference color). Is referred to as a dark color module). For this reason, in the optical code of the present invention, if general-purpose data is recorded in each module in accordance with the standard of the existing black-and-white optical code, the general-purpose data can be read by the existing reader for reading the black-and-white optical code. On the other hand, in the existing reading device, it is impossible to identify which reference color is used for the light color module and the dark color module, so that the dedicated data recorded in the optical code cannot be read. If it is identified by which reference color each module is colored using the dedicated data recorded in the optical code can be read. As described above, according to the optical code of the present invention, general-purpose data can be recorded in a form that can be read by an existing reader. Therefore, data recorded in a standardized monochrome optical code can be recorded as general-purpose data. Thus, compatibility with the standardized monochrome optical code can be ensured. In addition, since the optical code of the present invention can record two types of data, general-purpose data and dedicated data, in each module, the recording density is higher than that of a monochrome optical code that can record only 1-bit data in one module. There is an advantage that it can be increased. Moreover, since the dedicated data recorded on the optical code cannot be read by an existing reader, it is suitable for recording confidential information that can be read only by a specific person.

  It is proposed that the optical code of the present invention is a two-dimensional code formed by arranging modules in a matrix, for example.

  When the optical code is a two-dimensional code, it is determined in advance whether the light color reference color or the dark color reference color is used, and includes a fixed region that forms a pattern that assists optical reading. It is proposed that the area includes a sample area formed by arranging all kinds of reference colors on modules at predetermined positions.

  In such a configuration, there is an advantage that the identification error of the color of each module can be reduced by identifying the color of the module for recording data on the basis of the color of each module in the sample area. That is, in the optical code of the present invention, the identification error of the reference color of each module increases due to the influence of aging of ink and paper, the printer, the display device, the ambient illumination, etc., and the reading of the optical code is hindered. There is a fear. In such a configuration, the reference color of each module in the sample area is affected by changes in ink and paper, printers, display devices, ambient lighting, etc. Since it changes in the same way as the color, when identifying the color of each module, by comparing it with the reference color of each module in the sample area, you can eliminate the change over time and other influences, which reference color each module has It is possible to accurately identify the color scheme.

  When the optical code is a two-dimensional code, the optical code includes a data section for recording data code words for general data and dedicated data, and an error correction section for recording error correction code words for general data and dedicated data. Each module of the unit records the first type of error correction code word according to information on whether it is a light reference color or a dark reference color, and which type of reference is selected from the light reference color or the dark reference color The second type error correction code word is recorded according to the color information. The first type error correction code word is a correction target only for general-purpose data, and the second type error correction code word is a general purpose data. Data and dedicated data are subject to correction, and the second type of error correction codeword is proposed to include multiple bits of data recorded in one module of the data section in one error correction unit. That.

  With such a configuration, it becomes possible to efficiently correct an identification error in the color of the module that occurs when the optical code is read. That is, in the optical code of the present invention, since one module is arranged with various kinds of reference colors, the identification error of the reference color of each module is more likely to occur in units of modules compared to the black and white two-dimensional code. There are features. If an identification error occurs in a reference color of a module, errors occur in a concentrated manner in a plurality of bits of data recorded in the module. Therefore, as in this configuration, a plurality of bits included in one module If data is included in one error correction unit, the number of error correction units to be error-corrected can be reduced when an error occurs in the data due to an identification error of the reference color.

  In addition, at least some of the modules are subdivided into sub-modules smaller than the module in a matrix, and each sub-module is identified as one of the plurality of types of reference colors. In a module that is color-coded and is identified as a light color, a sub-module of a predetermined ratio or more is color-coded with a light reference color, and in a module that is identified as a dark color, the sub-module of a predetermined ratio or more is a dark color reference A configuration is proposed in which the dedicated data is recorded in accordance with information indicating which type of reference color is a bright reference color or a dark reference color among the sub-modules constituting the module.

  In such a configuration, it is possible to further increase the recording density while maintaining compatibility with the standardized conventional black and white two-dimensional code.

  Further, in the above-described configuration, the modules that are subdivided into sub-modules that are identified as light colors are all sub-modules that are arranged in a light reference color, and all modules that are identified as dark colors are all It is proposed that the sub-modules are arranged in a dark reference color.

  In such a configuration, all the sub-modules constituting one module are uniformly arranged in either the bright color reference color or the dark color reference color, so that each module is arranged by the reader for monochrome optical code. It becomes possible to accurately identify whether the color is light or dark.

  Further, in the present invention, a configuration is proposed which is a barcode in which parallel bars made up of modules identified as light colors and parallel bars made up of modules identified as dark colors are arranged in the reading direction.

  In such a configuration, since each parallel bar constituting the barcode is configured integrally with one of the light color module and the dark color module, when such a barcode is read by an existing barcode reader, Parallel bars composed of light color modules are identified as light colors, and parallel bars composed of dark color modules are identified as dark colors. For this reason, if general-purpose data is recorded in such a bar code using binary values of parallel bars in the same manner as a standard black and white bar code, the general-purpose data can be read by an existing bar code reader. Such a barcode is compatible with an existing barcode. The modules constituting each parallel bar may be unified with the same reference color for each parallel bar. However, the arrangement of the reference colors for each module increases the dedicated data recording capacity. This is preferable.

  Further, in the above configuration, it is proposed that each module records an error correction code word of general-purpose data according to information on which kind of reference color is selected from light color reference color or dark color reference color. Is done.

  Existing barcodes do not have an error correction function, so reading errors are likely to occur. For product barcodes, etc., it may take time to read, but in such a configuration, error correction code words related to general-purpose data will be used. By reading with a dedicated reading device, it becomes possible to perform error correction at the time of reading the general-purpose data, so that the general-purpose data can be read easily as compared with the existing black and white barcode.

  Further, in the above configuration, at least some of the modules are multi-staged into a plurality of stages of submodules in a direction orthogonal to the reading direction, and each of the submodules constituting each module has a plurality of types of bright color reference colors or It is proposed that colors are arranged in a plurality of types of dark reference colors.

  With such a configuration, it is possible to further increase the recording density while maintaining compatibility with a standardized monochrome bar code.

  In addition, as a method for generating the optical code, a first encoding step for encoding general-purpose data, a second encoding step for encoding dedicated data, and the encoded general-purpose data and dedicated data for each module. And a third encoding step for determining the color scheme of each module based on an encoding table in which the content of the recording unit data is associated with the color scheme of the module. An optical code generation method characterized by the above is proposed.

  In such a method, even if a reader capable of optically identifying the reference color of each module is used, if the contents of the encoding table are not known, the dedicated data can be decoded from the reference color of each module. Therefore, the confidentiality of the dedicated data recorded on the optical code can be improved.

  Further, in the above generation method, the encoding table is a one-to-many correspondence between the contents of the recording unit data and the color scheme of the module. In the third encoding step, based on the encoding table, It is proposed to extract a plurality of module color scheme candidates corresponding to the contents of the recording unit data and determine any one of the plurality of color scheme candidates.

  In such a configuration, it becomes difficult to guess the contents of the encoding table from the color arrangement pattern of each module, and therefore it is possible to reduce the possibility of decoding the dedicated data.

  In the above generation method, it is proposed that the first encoding step and the second encoding step encode the general-purpose data and the dedicated data in the same manner.

  In such a configuration, data can be encoded using a common algorithm in the first encoding step and the second encoding step, so that there is an advantage that the optical code generation program can be simplified. In addition, since a common algorithm can be used when decoding general-purpose data and dedicated data, there is an advantage that an optical code reading program can be simplified.

  Further, in the above generation method, in the third encoding step, one encoding table is selected from a plurality of encoding tables having different correspondences between the contents of the recording unit data and the color scheme of the module. It is proposed to determine the color scheme of each module based on the coding table.

  In order to decode the dedicated data recorded in the optical code, it is necessary to know the contents of the encoding table used at the time of encoding. If the encoding table used at the time of encoding is common, the optical code is decoded using the encoding table used by another optical code. In this configuration, at the time of encoding, Since the encoding table to be used is not constant, reading of the dedicated data of the optical code can be restricted even when the encoding table used by another optical code is known.

  Further, in the above generation method, in the first encoding step, the general data is converted into a data code word obtained by encoding the general data, and an error correction code word is generated from the data code word. In the second encoding step, the dedicated data is converted into a data code word for encoding the dedicated data, and an error correction code having a lower error correction rate than the first encoding step is converted from the data code word. It is proposed to generate words or not generate error correction codewords.

  As described above, it is possible to improve the confidentiality of the dedicated data by keeping the encoding table used for encoding the optical code secret. The person may sequentially apply possible encoding tables. In this case, since the error can be corrected within the range of the error correction rate of the error correction function, the attacker approximates the correct encoding table as well as the case where the encoding table used for encoding is selected. Even when an encoding table to be selected is selected, the dedicated data can be decoded using the error correction function. In response to such an attack, in such a configuration, the error correction rate of the error correction code word is lower than that of general-purpose data, or the error correction function is disabled without recording the error correction code word. Even when an encoding table similar to the encoding table is selected, there is an advantage that the dedicated data is difficult to decode.

  As described above, according to the optical code of the present invention, the conventional data standardized in the dedicated data portion while maintaining compatibility with the standardized monochrome optical code in the general-purpose data portion. The recording density can be increased as compared with the monochrome optical code.

(A) is the schematic of the optical code 1 of Example 1, (b) is explanatory drawing which shows each area | region of the optical code 1 of Example 1 according to the function according to the pattern. It is a chart which shows the contents of 16 kinds of standard colors. (A) is the optical code 1 of the first embodiment, and (b) is a two-dimensional code 11 having compatibility with the optical code 1 of the first embodiment. 3 is a flowchart showing a method for generating the optical code 1; It is a flowchart which shows the processing content of an encoding process. 6 is a chart illustrating an encoding table according to the first embodiment. 3 is a flowchart showing a method for decoding optical code 1. (A) is a chart showing the data arrangement of the optical code 1 of Example 1, and (b) is a chart showing the data arrangement of the optical code of Example 2. 6 is a schematic diagram of an optical cord 1a of Example 3. FIG. (A) is explanatory drawing showing the functional area of the module 2 which concerns on Example 3, (b) is the schematic of the light color module 2a which concerns on Example 3, (c) is Example 3. FIG. It is the schematic of the dark color module 2b which concerns on. 6 is a schematic diagram of an optical cord 1b of Example 4. FIG. (A) is the optical code 1b of Example 4, and (b) is the barcode 12 having compatibility with the optical code 1b of Example 4. 10 is a chart showing a data arrangement of an optical code 1b of Example 4. 10 is a schematic diagram of an optical cord 1c of Example 5. FIG.

  Embodiments of the present invention are described according to the following examples.

  The optical code 1 of this embodiment is compatible with the most popular QR code (registered trademark) among two-dimensional codes. Specifically, as shown in FIG. 1 (a), the optical code 1 of this embodiment is formed by arranging 21 square modules 2 in a matrix form vertically and horizontally. The module 2 of the optical code 1 is not composed of only white and black, but its basic structure conforms to the QR code. That is, as shown in FIG. 1B, the optical code 1 is composed of a functional pattern (fixed area) 3 and an encoding area 4 in the same manner as the QR code. The function pattern 3 is an area in the QR code where the module color pattern is predetermined, and is composed of a position detection pattern 5, a separation pattern 6, a timing pattern 7 and the like that assist optical reading of the optical code 1. The The encoding area 4 is an area in which data is recorded according to the color scheme of each module 2, and a data code area 8 in which data code words and error correction code words are recorded, and a format in which codes indicating format information are arranged. And an information code area 9. Since such a configuration basically conforms to the JIS standard (JIS X 0510: 2004) of the QR code, detailed description thereof is omitted.

  Although it is a monochrome image, it is not sufficiently represented in FIG. 1A, but each module 2 constituting the optical code 1 is arranged in one of a plurality of types of reference colors having different RGB values. As shown in FIG. 2, in this embodiment, there are 16 types of reference colors, and reference color codes from 0000 to 1111 are assigned to each reference color in binary notation. Of the 16 types of reference colors, 8 types are classified as light color reference colors, and the other 8 types are classified as dark color reference colors. All the bright reference colors have a luminance of 0.75 or more, and all the dark reference colors have a luminance of 0.25 or less. That is, the luminance 0.75 corresponds to the light color threshold according to the present invention, and the luminance 0.25 corresponds to the dark color threshold according to the present invention. The existing general QR code reader simply determines whether each module is white (light color) or black (dark color) based on the reflectance and luminance values when reading the QR code. Therefore, in the existing general reading apparatus, the module arranged with the high-brightness light color reference color becomes the light color module 2a identified as white (light color), and the module arranged with the low-brightness dark color reference color. Is a dark color module 2b identified as black (dark color). In this embodiment, the brightness difference between the light color module 2a and the dark color module 2b is set to a large value of 0.5 or more, so that the QR code reader can reliably identify the light color module 2a and the dark color module 2b. I can do it.

  As described above, the QR code reader recognizes only whether each module 2 is light or dark, but a dedicated reader having a reference color identification function (hereinafter referred to as a dedicated reader). ) Can be used to identify the color scheme of each module 2. In this embodiment, as shown in FIG. 2, 16 types of reference colors are selected so that the difference in RGB values between the reference colors is increased, and thus the dedicated reading device allows each module 2 to select which reference color. So that it can be accurately identified.

  Further, in this embodiment, as shown in FIG. 1B, the dedicated reading device is provided on the upper left of the position detection pattern 5 so as to easily identify which reference color each module 2 is. The sample area 5a is colored with 16 kinds of reference colors. More specifically, the sample area 5a is an area formed by arranging 16 modules 2 one by one with 16 kinds of reference colors, and the sample area 5a is disposed anywhere on the optical code 1 so that the sample area 5a is arranged. Which of the modules 2 is arranged with which reference color is determined in advance. In this way, since each module 2 included in the sample area 5a is always arranged in a standard color that is defined, the dedicated reading device performs encoding by comparing and contrasting with the color of the module 2 in the sample area 5a. It is possible to accurately identify which reference color the module 2 in the region 4 is. That is, when the reference color of each module 2 is identified from the RGB value of the image data obtained by imaging the optical code 1, there is a high possibility that the identification error of the reference color will occur due to the change of ink over time or the imaging environment. However, in such a configuration, the reference color can be identified by determining the reference color by comparing with the module 2 in the sample area 5a, thereby eliminating the influence of the change with time of the ink and the imaging environment. Errors can be reduced. In the sample area 5a, the light color module 2a is arranged at the position where the color is white and the dark module 2b is arranged at the position where the color is black in the position detection pattern 5 of the QR code. The function of the position detection pattern 5 is not hindered. The sample area 5a can also function as an identification code indicating that the optical code 1 is colored with 16 kinds of reference colors.

  As described above, in the optical code 1 of the present embodiment, each module 2 in the encoding area 4 is arranged with 16 kinds of reference colors, so that the monochrome optical code can record only 1 bit of information per module. In contrast, the optical code 1 of this embodiment can record 4-bit information per module. Here, in this embodiment, whether each module 2 is a bright color reference color or a dark color reference color can be identified by a QR code reader, and each module 2 can be identified as a light color reference color. Which reference color is the color or dark reference color cannot be identified by a QR code reader. For this reason, in this embodiment, each module 2 records general-purpose data that can be read by a QR code reading device according to information on whether the light color reference color or the dark color reference color. The module 2 records dedicated data that can be read only by a dedicated reading device according to information on which reference color is a bright color reference color or a dark color reference color.

  Specifically, the general-purpose data is recorded in the encoding area 4 of the optical code 1 as a light / dark binary pattern based on the light reference color and the dark reference color in accordance with the QR code standard. When the optical code 1 is read by a QR code reading device, the reading device recognizes the light color module 2a as white (light color) and the dark color module 2b without identifying the color of each module 2 in detail. Is identified as black (dark color), and the general-purpose data is decoded according to the QR code decoding process. FIG. 3A shows the optical code 1 of the present embodiment, and FIG. 3B shows the optical code 1 of FIG. 3A, in which all the light color reference colors are white and dark color reference colors. Is the QR code 11 obtained as a black paint. Since this QR code 11 records the same general-purpose data as the optical code 1 by the light / dark binary pattern of the module, when the optical code 1 and the QR code 11 in FIG. 3 are read by a QR code reader In both cases, the same general-purpose data is read. That is, the optical code 1 of this embodiment can function as an equivalent of the QR code to the QR code reader, and is compatible with the QR code.

  The general-purpose data is recorded as a light / dark binary pattern of each module 2, whereas the dedicated data is in the encoding area 4 and each module 2 has which reference color of the light color reference color and the dark color reference color. It is recorded by the information of whether or not. Since there are eight types of light color reference colors and dark color reference colors, 3 bits of dedicated data can be recorded for each module 2. That is, the optical code 1 of this embodiment can store dedicated data having a capacity three times that of general-purpose data. Since the storage capacity of the general-purpose data is the same as the storage capacity of the QR code 11 having the same number of modules, the optical code 1 of the present embodiment realizes a storage density four times that of the QR code.

  Further, since the reference color of each module 2 of the optical code 1 cannot be identified by a QR code reader, and cannot be identified unless it is a dedicated reader, the dedicated data recorded on the optical code 1 has a certain level of confidentiality. doing. For this reason, the optical code 1 of the present embodiment has an advantage that two types of information, that is, public information and confidential information can be recorded by recording public information as general-purpose data and recording confidential information as dedicated data. In particular, in the present embodiment, the confidential information (dedicated data) is recorded in a color arrangement pattern independent of the light / dark binary pattern of the module 2 that records the general-purpose data. Therefore, depending on the information amount of the confidential information (dedicated data), The amount of information of public information (general data) is not limited. In addition, since the dedicated data can record a larger amount of information than the general-purpose data, the optical code 1 of this embodiment has an advantage that a larger amount of confidential information can be recorded than public information.

  In this embodiment, three sets of dedicated data can be recorded on the optical code 1. The three sets of dedicated data are not recorded in different modules 2 in the encoding area 4 but are recorded so as to overlap each module 2 in the encoding area 4. Specifically, 3 bits of dedicated data can be recorded in each module 2 in the encoding area 4, but 1 bit of each set of dedicated data is recorded in each module 2. That is, when one set of dedicated data is recorded on the optical code 1, the encoded dedicated data is recorded on each module 2 by one bit. When three sets of dedicated data are recorded on the optical code 1, 1 set of dedicated data is recorded in each module 2 for three sets (3 bits). The recording mode of the dedicated data will be described in detail by a method for generating the optical code 1.

Hereinafter, a method for generating the optical code 1 will be described.
FIG. 4 is a flowchart for generating the optical code 1. First, in step S100, a data set to be recorded on the optical code 1 is prepared. The data set is one set of general-purpose data DS0 and one to three sets of dedicated data DS1, DS2, DS3.

  In the next step S110, the general-purpose data DS0 is two-dimensionally encoded in accordance with a normal QR code generation procedure, and a code A0 corresponding to the color arrangement pattern of the QR code is generated. That is, the code A0 is the code itself of the QR code 11 (see FIG. 3B) for recording the general-purpose data DS0. The code A0 includes the function pattern 3 and the modules 2 constituting the encoding area 4. The light / dark binary pattern is included. Since this procedure is a QR code procedure, a detailed description thereof will be omitted.

  In the next steps S120 and S130, the dedicated data DS1, DS2, and DS3 are two-dimensionally encoded in accordance with a normal QR code generation procedure, and codes A1, A2, and A3 corresponding to the QR code color pattern are generated. . That is, the codes A1, A2, and A3 are QR code data themselves that record the dedicated data DS1, DS2, and DS3. When the codes A1, A2 and A3 are generated, the QR code has the same version as the code A0 so that it can be combined with the code A0. In addition, an error correction code word conforming to the QR code standard is added to the codes A1 to A3. In this embodiment, in order to make it difficult to illegally decode the dedicated data, respectively. Is made lower than the code A0 so as to be the lowest level of the QR code. Since the encoding of the dedicated data DS1, DS2, DS3 is the same as the procedure of the QR code, detailed description is omitted.

  By the procedure up to step S130, QR codes A0, A1, A2, and A3 on the data that record one set of general-purpose data DS0 and one to three sets of dedicated data DS1, DS2, and DS3, respectively, are obtained. As described above, these QR codes A0 to A3 are generated in the same version so that the respective function patterns overlap with the coding areas. The coding process of step S200 is to synthesize the respective colors of these QR codes A0 to A3 for each overlapping module and convert them into the color arrangement pattern of the module 2 of the optical code 1. In the method of generating the optical code 1 shown in the flowchart of FIG. 4, the first encoding step according to the present invention is mainly realized by step S110. The second encoding step according to the present invention is mainly realized by step S120. The third encoding step according to the present invention is mainly realized by step S200.

In the encoding process S200, the color code of each module 2 of the optical code 1 is determined by combining the QR codes A0, A1, A2, and A3. Specifically, when the number of modules one side of the optical code 1 for generating a N, the whole optical code 1, there are ^{N 2} pieces of module 2, also QR code A0, A1, A2, A3, ^{N 2} There is a color scheme pattern of modules. The color scheme for all the N ² modules 2 is determined one by one. More specifically, assuming that the vertical module index of the QR code is I and the horizontal module index is J, all modules can be expressed by combinations of I = 1 to N and J = 1 to N. The color of the module indicated by I and J is expressed by C (I, J). If the codes A0, A1, A2, and A3 are represented by K, they can be represented by C (I, J, K). Here, K is 0 to 3.

  FIG. 5 is a flowchart showing the contents of the encoding process. In step S210, it is determined whether or not the module 2 designated by I and J is the module 2 constituting the function pattern 3. If it is determined that the module 2 constitutes the function pattern 3, the color arrangement is determined based on the position of the module 2 in step S220. On the other hand, if it is determined that the module 2 is included in the coding area 4, the color arrangement pattern of the QR codes A0 to A3 is read in the next step S230. Specifically, the color arrangement data of C (I, J, K) (K is 0 to 3) is read to identify whether each module is 0 or 1 (white or black). Next, in step S240, the color scheme patterns of the modules of the QR codes A0, A1, A2, and A3 are combined. Specifically, when four sets of QR codes A0, A1, A2, and A3 are recorded, a color combination of the module of each set is created, for example, white, white, white, and white (0010). The combination of these four colors becomes a recording unit for general-purpose data and dedicated data to be recorded in one module 2. Next, in step S250, a coding table for determining the color scheme of module 2 is selected. As shown in FIG. 6, the encoding table is a one-to-one correspondence between the data recorded in the module 2 and the reference color code of the module 2. The same encoding table can always be used, but by selectively using a plurality of types of encoding tables with different correspondences, by limiting the number of people who know the contents of the used encoding table, The confidentiality of the dedicated data can be improved. In step S260, using the selected encoding table, the color scheme of module 2 is determined from the combination of four colors serving as recording units. In step S270, it is determined whether or not the above processing has been completed for all modules 2. If the processing of all modules 2 has been completed, the encoding processing is terminated.

  As described above, in the method for generating the optical code 1 of the present embodiment, the general-purpose data DS0 and the dedicated data DS1, DS2, DS3 are respectively QR-coded, and the QR codes A0, A1, A2, A3 on the data are synthesized. The color arrangement of the optical code 1 is determined. In such a generation method, since both the general-purpose data and the dedicated data are encoded in accordance with the QR code encoding method, the optical code 1 is generated by using a common algorithm for encoding the general-purpose data and the dedicated data. There is an advantage that the program can be simplified. Further, since the optical code 1 generated by such a generation method can use a common algorithm when decoding general-purpose data and dedicated data, the reading program for the optical code 1 can be simplified.

  In such a generation method, data to be recorded in each module 2 is converted into one of 16 types of reference colors and recorded using an encoding table. The content of the encoding table is arbitrarily determined in advance, and the content differs depending on the system to be applied. Therefore, by concealing this encoding table, the dedicated data can be protected from a third party. Since general-purpose data must be compatible with the QR code, the QR code is used regardless of the content of the encoding table as to whether each module 2 is color-coded in the light color reference color or the dark color reference color. It is comprised so that it may be determined uniquely according to the production | generation procedure.

  In the encoding table shown in FIG. 6, 4-bit data to be recorded in one module 2 and 16 types of reference color codes are associated with each other on a one-to-one basis. When the set of general-purpose data DS0 and the three sets of dedicated data DS1 to DS3 are recorded in the optical code 1, the color scheme of the module 2 can be uniquely determined from the data recorded in the module 2. On the other hand, when only one set of general-purpose data and dedicated data (for example, DS0 and DS1) is recorded in the optical code 1, data (2 bits) to be recorded in one module 2 in the encoding table, 16 The types of reference color codes are associated with each other on a one-to-four basis, and the color scheme of the module 2 cannot be uniquely determined from the data recorded in the module 2. Therefore, in such a case, four types of reference colors corresponding to the combination of data to be recorded are extracted as color scheme candidates for the module 2, and the reference color of the module 2 is selected from the extracted color scheme candidates by lottery or the like. That's fine. Thus, in the encoding table, when the data to be recorded in one module 2 and the color scheme of the module 2 correspond one-to-many, the contents of the encoding table are estimated from the optical code 1. Since it becomes difficult, there is an advantage that the confidentiality of the dedicated data can be improved.

Next, a reading method when reading the optical code 1 of the first embodiment with a dedicated reading device will be described.
FIG. 7 is a flowchart showing an optical code reading process by the dedicated reading device. In the first step S300, the optical code 1 is imaged by an imaging device provided in the reading device. Next, in step S310, the optical code 1 is identified from the captured image according to the QR code image identification procedure, and the module 2 is cut out. Specifically, for each module 2, the corresponding pixel data is extracted from the image. Next, in step S320, it is determined whether or not the sample area 5a exists in the function pattern 3 of the optical code 1. As a result of the determination, when it is determined that the sample area 5a does not exist, that is, it is a normal QR code, the process proceeds to step S330, where a normal QR code reading process is performed, and the data recorded in the QR code is read. The reading process ends. Since this QR code reading process is known, a detailed description thereof will be omitted. On the other hand, if it is determined in step S320 that the sample area 5a exists, the process proceeds to step S340, where 16 types of reference colors included in the sample area 5a are extracted as comparison references, and RGB values are measured.

  In step S350, the reference color of the module 2 is identified from the extracted image data of each module 2. Specifically, the color of the module 2 is converted into an RGB value or the like, and the numerical value is compared with the numerical value of each reference color extracted from the sample area 5a. To be identified. In step S360, the reference color of the module 2 identified in S350 is decoded into 4-bit data recorded in the module 2 based on a previously stored decoding table. The decoding table has substantially the same contents as the encoding table (see FIG. 6) used when generating the optical code. With this decoding table, the reference color code of the module 2 is a module unit such as black, black and white. Is converted into a combination of the four colors recorded. Steps S350 and 360 are repeated one by one for each module 2 in the coding area 4. In step S370, it is determined whether the above processing is completed for all modules 2. If the processing for all modules 2 is completed, the process proceeds to step S380. In step S380, the 4-bit data decoded for each module 2 is combined for each data set to obtain QR codes A0 to A3 obtained by coding the data DS0 to DS3 of each data set. In step S390, the QR codes A1, A2, and A3 for recording the dedicated data are decoded into dedicated data DS1, DS2, and DS3 in accordance with a normal QR code decoding procedure. In the next step S400, the QR code A0 for recording the general-purpose data is decoded into the general-purpose data DS0 according to a normal QR code decoding procedure, and the optical code 1 reading process is terminated.

  As can be seen from the optical code 1 reading method described above, in the optical code 1 of this embodiment, general-purpose data is two-dimensionally encoded according to the QR code standard, and each module 2 can be either light or dark. Since it is recorded according to certain information, general-purpose data can be read by a QR code reader. On the other hand, the dedicated data is recorded by information on which reference color each module 2 is, and since it is encrypted by the encoding table, 16 kinds of reference colors can be optically identified, and the code Only the dedicated reader that stores the decoding table corresponding to the conversion table can be read.

Next, an error correction method for the optical code 1 of this embodiment will be described.
Since the error correction method of the optical code 1 of the present embodiment is based on the error correction method of the QR code, first, the error correction method of the QR code will be described. In the QR code, the data code word is stored in the encoding area. A data portion to be recorded and an error correction portion to record the error correction code word are provided. The error correction code word is generated after the data code by the Reed-Solomon code method. The Reed-Solomon code corrects a plurality of bits as error correction units (symbols), and the QR code generates an error correction code word using an 8-bit data code word as one symbol.

  In the first embodiment, as described above, the data sets DS0 to DS3 of general-purpose data and dedicated data are converted into codes A0 to A3 corresponding to the color arrangement pattern of the QR code and recorded. At this time, each of the data sets DS0 to DS3 is converted into a data code word according to a QR code generation method, and an error correction code word for correcting the data code word is added. Specifically, the general-purpose data set DS0 is converted into the data code word Ad0, and the error correction code word Ac0 is generated with the 8-bit data code word Ad0 as one symbol. Similarly, the data sets DS1 to DS3 of dedicated data are also converted into data code words Ad1, Ad2, Ad3, respectively, and the error correction code words Ac1, Ac2 are set with 8 bits of each data code word Ad1, Ad2, Ad3 as one symbol. , Ac3 is generated.

  FIG. 8A shows the data arrangement of the optical code 1 of the first embodiment. Here, the “surface layer” is a data area readable by a QR code reader, in which one bit is recorded in one module by the light / dark binary pattern of the module 2, and the “inner layer” is more detailed. This is a data area in which 3 bits are recorded in one module depending on the type of the reference color and cannot be read by a QR code reader. In the encoding area 4, the data code word Ad0 of general-purpose data is recorded in the data portion of the surface layer, and the error correction code word Ac0 of general-purpose data is recorded in the error correction portion of the surface layer. In the encoding area 4, the data code words Ad1, Ad2, Ad3 of the dedicated data are recorded in the inner layer data portion, and the error correction code words Ac1, Ac2, Ac3 are recorded in the inner layer error correction portion.

  As described above, in this embodiment, for each of the data sets DS0 to DS3 recorded in the optical code 1, the error correction code words Ac0 to Ac3 are generated according to the QR code generation procedure, and the data code words Ad0 to Ad3 are encoded. Is recorded in the recording area 4. The error correction code words Ac0 to Ac3 recorded in this way are used when decoding the codes A0 to A3 of each data set in the reading process of the optical code 1. Since error correction of each data set is performed in accordance with the error correction procedure of QR code, detailed description is omitted.

  In the present embodiment, the error correction method is changed from the first embodiment. Since the configuration other than the error correction method is the same as that of the first embodiment, the common parts of the configuration are denoted by the same reference numerals in the drawings and text, and the description thereof is omitted.

  The present embodiment is characterized in that an error correction code word is recorded with 8-bit data recorded in two modules 2 for recording data code words Ad0 to Ad3 as an error correction unit (symbol). More specifically, in the first embodiment, the error correction code word Ac0 is generated using the 8-bit data code word Ad0 as one symbol, and the error correction code word Ac1 is generated using the 8-bit data code word Ad1 as one symbol. In other words, error correction code words Ac0 to Ac3 are generated for each data set. On the other hand, in the present embodiment, an error correction code word Ac4 is generated with 8 bits of data recorded in two modules as one symbol, and an optical code is used instead of the error correction code words Ac1 to Ac3 related to dedicated data. Record. For the purpose of maintaining compatibility with the QR code, the error code word Ac0 related to general-purpose data is generated from the data code word Ad0 and recorded in the optical code as in the first embodiment.

  More specifically, when the optical code of the present embodiment is generated, the data sets DS0 to DS3 of general-purpose data and dedicated data are converted into codes A0 to A3 corresponding to the color arrangement pattern of the QR code as in the first embodiment. Convert and record. At this time, each of the data sets DS0 to DS3 is converted into data code words Ad0 to Ad3 according to a QR code generation method, and error correction data words Ac0 to Ac3 are generated from the data code words. At this time, with respect to the dedicated data, the generated error correction code words Ac1, Ac2 and Ac3 are not recorded, but separately, error correction code words having 8-bit data recorded in the two modules 2 of the data portion as one symbol. Ac4 is generated. In the present embodiment, in order to increase the error correction rate, the error correction code word Ac4 that is twice the amount of the data code words Ad0 to Ad3 is generated.

  FIG. 8B shows the data arrangement of the optical code of the present embodiment. As can be seen from comparison with the data arrangement of the first embodiment (see FIG. 8A), in both the present embodiment and the first embodiment, the data code word Ad0 is included in the surface layer of the error correction unit in the encoding area 4. The generated error correction code word Ac0 is recorded. On the other hand, in the first embodiment, the error correction codewords Ac1, Ac2, and Ac3 are recorded in the inner layer of the error correction unit, whereas in the present embodiment, the error correction codeword Ac4 is recorded in the inner layer of the error correction unit. Is done. That is, in such a configuration, the error correction code word Ac0 corresponds to the “first correction code word” according to the present invention, and the error correction code word Ac4 corresponds to the “second correction code word” according to the present invention. Equivalent to. In this embodiment, since the error correction code word Ac4 exceeds the storage capacity of the inner layer of the error correction unit, a part of the error correction code word Ac4 is also recorded in the inner layer of the module 2 constituting the function pattern 3. doing. The module 2 constituting the function pattern 3 does not have any problem even if the error correction code word Ac4 is recorded because there is no data recorded in the inner layer except for the sample area 5a.

  As described above, in this embodiment, the error correction code word Ac0 generated from the data code word Ad0 of general-purpose data and all the data code words Ad0, Ad1, Ad2, and Ad3 are generated in units of two modules. There are two types of error correction code word Ac4. For this reason, in the optical code reading process of this embodiment, two types of error correction based on the individual error correction code words Ac0 and Ac4 are performed in order. Here, in this embodiment, when error correction by one error correction code word Ac0, Ac4 fails, error correction by the other error correction code word Ac0, Ac4 is attempted and the error correction is successful. Try again to correct the error that failed. In the two types of error correction code words Ac0 and Ac4, the error correction target data partially overlaps. Therefore, even if one of the error corrections fails, the error correction of the duplicate data is reduced by the other error correction. This is because there is a possibility that the error correction of the failed one will be successful.

  In the present embodiment, the error correction function can be improved as compared with the first embodiment by generating and recording the error correction code word Ac4 using the 8-bit data recorded in the two modules as one symbol of the Reed-Solomon code. There are advantages. That is, in the optical code of the present embodiment, each module 2 is arranged with 16 kinds of reference colors, so that a color identification error is more likely to occur in units of modules than the monochrome optical code. In the error correction method according to the first embodiment, 4-bit data recorded in one module 2 is included in different error correction units (symbols). An error will occur in the symbol. On the other hand, in this embodiment, 8-bit data recorded in two modules 2 constitutes one error correction unit (symbol), so even when the color identification of one module is wrong. It is only necessary to generate an error with a maximum of two symbols. In general, in the Reed-Solomon code, whether or not an error can be corrected is determined depending on the proportion of symbols in which an error has occurred. It becomes easy to correct errors. Note that the error occurs in two symbols instead of one symbol because the error correction code word Ac0 is recorded on the surface layer in order to maintain compatibility.

  In this embodiment, 8-bit data recorded in two modules 2 constitutes one error correction unit. However, in the present invention, a plurality of bits recorded in one module 2 is used. Data can also be used as one error correction unit. Further, when a large number (16 bits) of data is recorded in one module 2 as in Example 3 described later, the large number of data is stored in two or more error correction units (for example, 8 bits × 2).

  The present embodiment is characterized in that the configuration of the second embodiment is changed and each module is divided into fine sub-modules so that more data can be recorded in each module. In addition, since it is the same structure as Example 1 except the characteristic part of this invention demonstrated below, the part which has a common structure makes a code | symbol common in a figure and the text, and abbreviate | omits description.

  Specifically, as shown in FIG. 9, in the optical code 1a of the present embodiment, the module 2 constituting the encoding region 4 is subdivided into submodules 20 smaller than the module 2, and the module 2 is At the level of the sub-module 20, colors are arranged with 16 reference colors (see FIG. 2). Specifically, the module 2 is divided into a total of 16 submodules 20 in 4 columns and 4 columns in a matrix. As shown in FIG. 10A, the module 2 subdivided into submodules 20 is divided into five regions ae, and the submodules 20 in the same regions ae are arranged in the same reference color. Composed. That is, each module 2 is arranged with a maximum of five types of reference colors. In addition, the 16 submodules 20 constituting each module 2 are arranged in a uniform color using the light color reference color or the dark color reference color. That is, as shown in FIG. 10B, in the module 2a in which the area a is colored with the light color reference color, all the remaining areas b to e are also colored with the light color reference color. The module 2a is identified as white (light color) when read by a QR code reader, and constitutes the light color module 2a. On the other hand, as shown in FIG. 10C, in the module 2b in which the area a is arranged with the dark reference color, all the remaining areas b to e are also arranged with the dark reference color. That is, the module 2b is a dark color module 2b that is identified as black (dark color) when read by a QR code reader.

As described above, even in this embodiment, each module 2 in the encoding area 4 is identified as either light or dark color by the QR code reader, and the optical code of this embodiment is used. In 1a, each module 2 records general-purpose data according to information on which of the light color reference color and the dark color reference color. In this embodiment, dedicated data is recorded based on information indicating which type of reference color is selected from the bright reference color or the dark reference color for each of the areas a to e of the module 2. Here, each of the light color module 2a and the dark color module 2b has 8 ⁵ (15 bits) color arrangement patterns because the ^five areas a to e can be individually arranged with 8 reference colors. . Therefore, the optical code 1c of this embodiment can record 1-bit general-purpose data and 15-bit dedicated data in one module 2.

  As described above, in this embodiment, each module 2 is subdivided into submodules 20 and is divided into a plurality of types of reference colors at the submodule 20 level. The recording density per module can be increased. In addition, each module 2 can be identified as a light color or a dark color by a QR code reader by unifying and arranging the modules 2 in a light color reference color or a dark color reference color. By recording data in the light / dark binary pattern using general-purpose data, compatibility with the QR code can be ensured.

  The optical code 1b of this embodiment is compatible with an EAN / JAN code that is a product barcode. Specifically, as shown in FIG. 11, the optical code 1b of the present embodiment is formed by arranging light or dark parallel bars 13 having four different widths in a line in the reading direction. In FIG. 11, decimal numbers written at the bottom of the EAN / JAN code are omitted. The parallel bar 13 of the optical code 1 is different from the EAN / JAN code in that it is colored with a color other than white and black, but its basic structure conforms to the EAN / JAN code. That is, as shown in FIG. 11 (b), the optical code 1b is provided with left and right guard bars 14, 14 and a central center bar 15 for control, like the EAN / JAN code. 6 characters are recorded between the left and right guard bars 14. Each character 16 includes two light parallel bars 13a and two dark parallel bars 13b. Each parallel bar 13 is formed by juxtaposing strip-shaped modules 2 having a unit width in the longitudinal direction. All the characters 16 are composed of seven modules 2, and each parallel bar 13 is composed of one to four modules 2, and can take four kinds of width dimensions according to the number of modules 2 to be configured. It is configured as follows. Since such a configuration basically conforms to the JIS standard (JIS X 0501: 1985), detailed description thereof is omitted.

  Since it is a monochrome image, it is not sufficiently represented in FIG. 11, but in this embodiment, as in the first embodiment, each module 2 that constitutes the optical code 1 b has a light color reference color and a dark color reference. The color is arranged in any of 16 kinds of reference colors (see FIG. 2) classified into colors. In such a configuration, the light color module 2a arranged with a light color reference color having a high luminance is identified as white (light color) by the reading device for the EAN / JAN code, and is arranged with a dark color reference color having a low luminance. The dark module 2b thus identified is identified as black (dark) by the EAN / JAN code reader. In the present embodiment, the light color parallel bar 13a is constituted by the light color module 2a, and the dark color parallel bar 13b is constituted by the dark color module 2b, whereby the width dimension of each light color and dark color parallel bar 13 is set to EAN. It is configured so that it can be identified by a reader for / JAN code. The optical code 1b of the present embodiment records general-purpose data according to the width dimensions of the light color parallel bar 13a and the dark color parallel bar 13b in accordance with the EAN / JAN code standard.

  FIG. 12A shows the optical code 1b of this embodiment, and FIG. 12B shows the optical code 1b of FIG. 12A, in which all the light color reference colors are white and dark color reference colors. Is a bar code (EAN / JAN code) 12 obtained as a black coating. This bar code 12 records the same general-purpose data as the optical code 1b according to the width dimension of the light and dark parallel bars. Therefore, the bar code 12 is a EAN / JAN code reader and the optical code 1b and bar code of FIG. 12 is read, the same general-purpose data is read in all cases. That is, the optical code 1b according to the present embodiment can function as an EAN / JAN code equivalent to a reader for EAN / JAN code, and is compatible with the EAN / JAN code. It has become.

  On the other hand, the optical code 1b according to the present embodiment records dedicated data that can be read only by a dedicated reading device depending on which type of reference color the light color reference color or dark color reference color is used by each module 2. To do. Since each module 2 can record 3-bit information in addition to representing the light / dark binary value of the parallel bar 13, it is possible to record 21-bit dedicated data on the character 16 composed of the seven modules 2. It has become.

  As described above, since the optical code 1b of this embodiment can record dedicated data of 21 bits per character, it can realize a recording density that is four times or more that of the existing EAN / JAN code. Further, since the general-purpose data can be read by the reading device for EAN / JAN code, the optical code 1b of this embodiment is also compatible with the EAN / JAN code.

  Existing EAN / JAN codes have an error detection function, but no error correction function. On the other hand, in the optical code 1b of the present embodiment, each module 2 records an error correction code word of general-purpose data according to information on which kind of reference color is a bright color reference color or a dark color reference color. it can. FIG. 13 shows an example of the data arrangement when an error correction code word of general-purpose data is recorded in the optical code 1b. Here, the “surface layer” is a data area that can be identified by a reader for EAN / JAN code, represented by the light / dark binary pattern of module 2, and the “inner layer” is a more detailed standard. This is a data area that is recorded according to the type of color and that cannot be read by a reader for EAN / JAN codes. In this example, a total of 28 bits of data can be recorded, 7 bits on the surface layer of each character 16 and 21 bits on the inner layer. The data code word (general data code word) of the general data recorded on the surface layer is Reed-Solomon. One symbol of the code. Since the Reed-Solomon code cannot have 7 symbols as 1 symbol, for convenience, a 7-bit general-purpose data code word with 1 bit of fixed data added to 8 bits is treated as 1 symbol. In this example, an error correction code word generated from the general-purpose data code word is recorded in the inner layer. Here, the error correction code word is recorded on the inner layer of one character 16 by 2 symbols (16 bits) at a time, and the data code word (dedicated data code word) of the dedicated data can be recorded in the remaining 5 bits. ing. In this way, when twice as many error correction code words are recorded with respect to symbols encoded with general-purpose data, the error is corrected if the error is 33% when read with a dedicated reader. Thus, general-purpose data can be read.

  In the present embodiment, the configuration of the optical cord 1b of the fourth embodiment is changed, and each module 2 is subdivided into a plurality of stages of submodules 20. In addition, since it is the same structure as Example 4 except the characteristic part of this invention demonstrated below, the part which has a common structure makes a code | symbol common in a figure and a text, and abbreviate | omits description.

  In the optical code 1c of this embodiment, as shown in FIG. 14, each module 2 is subdivided into four stages of submodules 20 in a direction orthogonal to the reading direction. Each module 2 is arranged with 16 types of reference colors (see FIG. 2) for each submodule 20. In this embodiment, all the four submodules 20 constituting the light color module 2a are arranged with the light reference color, and all the four submodules constituting the dark color module 2b are arranged with the dark color reference color. Thus, the EAN / JAN code reader can identify the light color module 2a as a light color and the dark color module 2b as a dark color. In this embodiment, as in the fourth embodiment, general-purpose data is recorded according to the width dimensions of the light parallel bars 13a and the dark parallel bars 13b in accordance with the EAN / JAN code standard.

  On the other hand, the optical code 1c according to the present embodiment has dedicated data that can be read only by a dedicated reading device depending on which type of reference color the light color reference color or the dark color reference color is used by each submodule 20. Record. Each sub-module 20 can record 3 bits of information in addition to representing the light / dark binary value of the parallel bar 13, and therefore can record 12 bits of information per module, and the character 16 composed of 7 modules 2. Can record 84-bit information.

  As described above, in this embodiment, each module 2 is subdivided into submodules 20 and is divided into a plurality of types of reference colors at the submodule 20 level. The recording density per module can be increased. In addition, since each module 2 is arranged in a uniform color reference color or dark reference color, each parallel bar 13 can be distinguished from a light color or a dark color by an EAN / JAN code reader. Compatibility with EAN / JAN codes can also be ensured.

  As mentioned above, although embodiment of this invention was described by the Example, this invention can add a various change in the range which is not restricted to the form of the said Example and does not deviate from the summary of this invention.

  For example, although the above embodiment exemplifies an optical code compatible with a QR code or an EAN / JAN code, the present invention is compatible with an optical code of a standard other than the QR code or the EAN / JAN code. Is also possible. In the above embodiment, the modules are arranged with 16 kinds of reference colors. However, in the present invention, the modules are arranged with at least two kinds of bright color reference colors and two or more kinds of dark color reference colors. If it is, it is enough. In addition, the reference color is not limited to one having a color, and gray of a plurality of gradations can be adopted. In the present invention, the color arrangement of the reference color is not limited to that expressed by solid coating of the ink of the reference color, and may be expressed by synthesis of fine halftone dots. The optical code of the present invention is not limited to the one printed on the printed material, but includes one displayed on the display screen.

1, 1a, 1b, 1c Optical code 2 Module 3 Function pattern 4 Coding area 5 Position detection pattern 5a Sample area 6 Separation pattern 7 Timing pattern 8 Data code area 9 Format information code area 11 QR code 12 Bar code 13 Parallel bar 14 Guard bar 15 Center bar 16 Character 20 Sub module

Claims (14)

An optical code comprising a module identified as light or dark,
Each module is arranged so that it can be distinguished from any of a plurality of types of reference colors having different RGB values.
The plurality of types of reference colors are composed of a plurality of bright color reference colors having a reflectance or luminance equal to or higher than a predetermined light color threshold, and a plurality of dark color reference colors having a reflectance or luminance equal to or lower than a predetermined dark color threshold,
Modules identified as light colors are colorably distinguishable from any of the light reference colors, modules identified as dark colors are colorably distinguishable from any of the dark color reference colors,
General-purpose data recorded based on whether each module is a light reference color or a dark reference color, and what type of reference color is a light reference color or a dark reference color An optical code comprising at least two types of data including dedicated data recorded by the above information.   The optical code according to claim 1, wherein the optical code is a two-dimensional code in which modules are arranged in a matrix. It is determined in advance whether the light color reference color or the dark color reference color is used, and includes a fixed region that forms a pattern that assists optical reading.
3. The optical code according to claim 2, wherein the fixed area includes a sample area in which all kinds of reference colors are arranged in modules at predetermined positions. A data part for recording data code words of general-purpose data and dedicated data; and an error correction part for recording error correction code words of general-purpose data and dedicated data;
Each module of the error correction unit records the first type of error correction code word according to information on whether it is a light color reference color or a dark color reference color, and which type of light color reference color or dark color reference color The second type error correction code word is recorded according to the information of whether it is the standard color of
The first type error correction code word is intended for correction only for general data, and the second type error correction code word is intended for correction for general data and dedicated data.
4. The optical code according to claim 2, wherein the second type of error correction code word includes a plurality of bits of data recorded in one module of the data portion in one error correction unit. . At least some of the modules are subdivided into a sub-module smaller than the module in a matrix,
In the module subdivided into the sub-modules, each sub-module is color-coded so that it can be distinguished from any of the plurality of types of reference colors, and in the modules identified as light colors, more than a predetermined proportion of the sub-modules are light-colored. In the module that is colored with the reference color and is identified as the dark color, the sub-modules of the predetermined ratio or more are colored with the dark color reference color,
5. The dedicated data is recorded according to information on which kind of reference color is selected from light color reference color or dark color reference color for each sub-module constituting the module. The optical code according to any one of the above.   Modules that are subdivided into sub-modules that are identified as light colors, all sub-modules are colored with a light reference color, and modules that are identified as dark are all sub-modules with a dark reference color The optical code according to claim 5, wherein the optical code is colored.   2. The optical code according to claim 1, wherein the optical code is a bar code formed by arranging parallel bars composed of modules identified as light colors and parallel bars composed of modules identified as dark colors in the reading direction.   8. The error correction code word of general-purpose data is recorded according to information on which type of reference color is selected from light color reference color or dark color reference color for each module. Optical code.   At least some of the modules are multi-staged into a plurality of stages of sub-modules in a direction perpendicular to the reading direction, and the sub-modules constituting each module are arranged in a plurality of types of light color reference colors or a plurality of types of dark color reference colors. The optical code according to claim 7, wherein the optical code is provided. An optical code generation method according to any one of claims 1 to 9,
A first encoding step for encoding generic data;
A second encoding step for encoding dedicated data;
The encoded general-purpose data and dedicated data are divided into recording unit data to be recorded for each module, and the color scheme of each module is determined based on an encoding table that associates the contents of the recording unit data with the module color scheme. And a third encoding step. An optical code generation method comprising:   The encoding table is a one-to-many correspondence between the contents of the recording unit data and the color scheme of the modules. In the third encoding step, the contents correspond to the contents of the recording unit data based on the encoding table. The method for generating an optical code according to claim 10, wherein a plurality of module color scheme candidates are extracted and determined as any one of the plurality of color scheme candidates.   The optical code generation method according to claim 10 or 11, wherein in the first encoding step and the second encoding step, the general-purpose data and the dedicated data are encoded by the same method.   In the third encoding step, one encoding table is selected from a plurality of encoding tables having different correspondences between the contents of the recording unit data and the color scheme of the modules, and each module is selected based on the selected encoding table. The optical code generation method according to claim 10, wherein a color arrangement is determined. In the first encoding step, the general-purpose data is converted into a data code word obtained by encoding the general-purpose data, and an error correction code word is generated from the data code word.
In the second encoding step, the dedicated data is converted into a data code word for encoding the dedicated data, and an error correction code having a lower error correction rate than the first encoding step is converted from the data code word. 14. The optical code generation method according to claim 10, wherein a word is generated or no error correction code word is generated.