JP3887947B2 - Two-dimensional code reading method and recording medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for reading a two-dimensional code.
[0002]
[Prior art]
Conventionally proposed two-dimensional codes include those described in JP-A-7-254037, for example. In this two-dimensional code, as shown in FIG. 15B, the information has a two-dimensional spread, and a much larger amount of information can be recorded as compared with the barcode shown in FIG. It is complicated.
[0003]
That is, as shown in FIG. 16, in order to facilitate the determination of the location of the two-dimensional code 500, for example, three positioning symbols 510a, 510b, and 510c combined with squares having a specific dimension ratio are used. Wait Yes. Between the three positioning symbols 510a, 510b, and 510c, there are timing cells 520a and 520b, which are reference patterns serving as indices of data cell positions in which white and black are alternately combined.
[0004]
The interior of the two-dimensional code 500 is divided into n × n square cells (hereinafter referred to as cells), and the positioning symbols 510a, 510b, and 510c have, for example, a length of one side corresponding to 7 cells. The black square 512, the white square 514 whose side is equivalent to 5 cells, and the black square 516 whose side is equivalent to 3 cells are concentrically superimposed.
[0005]
When the vicinity of the center of the positioning symbols 510a, 510b and 510c is linearly crossed, black, white, black, white and black patterns are detected at a ratio of 1: 1: 3: 1: 1. When black and white are detected alternately at the above ratio, the pattern is determined to be a strong candidate for the positioning symbols 510a, 510b, 510c, and the existence position of the two-dimensional code 500 is determined. Priority inspection.
[0006]
The shape of the two-dimensional code 500 can be estimated to be a parallelogram range uniquely determined by the three positioning symbols 510a, 510b, and 510c. The data is represented by cells (namely, data cells) in the region 530 excluding the positioning symbols and reference patterns, and each data cell is color-coded into white or black, whereby each data cell is 1-bit data. It corresponds to. However, in FIG. 16, the black and white pattern of the data cell is omitted for easy understanding.
[0007]
The position of each data cell can be obtained by simple calculation using the centers of the three positioning symbols 510a, 510b, and 510c and the two timing cells 520a and 520b as indices of the vertical and horizontal coordinates, respectively. .
By determining whether the position near the center of each data cell is black or white and determining the position in this way, black can be recognized as binary data by, for example, 1 and white corresponding to, for example, 0, Can be deciphered.
[0008]
In FIG. 16, the black and white pattern of the data cell 330 is omitted, but the cell size in the data cell 330 is the same as the cell size of the positioning symbols 310a, 310b, 310c.
[0009]
[Problems to be solved by the invention]
The size of one cell in such a two-dimensional code is required to be changed as appropriate according to the application. For example, if a label printed with a two-dimensional code is attached to an article, the cell size must be increased to some extent if it is necessary to read the two-dimensional code from the label while the article is moving at high speed. However, the cell size may be relatively small if the two-dimensional code is read from the label while the article is stopped or moving at a low speed.
[0010]
For example, it is preferable to read a two-dimensional code while moving at a high speed in order to sort a large number of articles at the article sorting stage. On the other hand, when the worker manually performs some processing on the sorted articles, for example, the two-dimensional code is read by a hand-held reader, but in this case, the cell size is smaller than that which can be read. The two-dimensional code is preferable because the two-dimensional code itself can be reduced.
[0011]
However, in order to realize this, for example, a label printed with a two-dimensional code having a relatively large cell size for reading during high-speed movement, and a two-dimensional code having a relatively small cell size for a hand-held reader. Two types of labels, such as a label printed with, must be prepared and each must be attached to an article. This leads to an increase in label creation and label attachment work.
[0012]
Of course, a two-dimensional code including data to be read during high-speed movement and data to be read by a hand-held reader can be formed in one label. However, since the cell size in this case has to be a cell size for reading during high-speed movement, the data to be read by a hand-held reading device need not be such a large cell size. Nevertheless, the cell size is larger than necessary. That is, the two-dimensional code itself becomes large. In the reading process, since only a predetermined range is read, if the two-dimensional code becomes large, the hardware and software configuration of the reading device must be adapted to cope with the large two-dimensional code. There is.
[0013]
From such a point of view, the present invention invents a two-dimensional code that can form a code with an appropriate cell size according to the application and can mix the codes according to the plurality of applications. An object is to provide a method of reading a code.
[0014]
[Means for Solving the Problems and Effects of the Invention]
The two-dimensional code reading method according to claim 1 is premised on reading the following two-dimensional code. That is, a positioning symbol that is arranged at a predetermined position in a two-dimensional code that expresses information by a cell distribution pattern and specifies the position of the two-dimensional code A timing cell that is a reference pattern serving as an index of each data cell position; First information expressed using a cell having the same cell size as a cell constituting the positioning symbol, and a first information expressed using a cell having a smaller cell size than the cell constituting the positioning symbol. Each of the two pieces of information is a two-dimensional code arranged at a predetermined position in the two-dimensional code. According to this two-dimensional code, a code can be formed with an appropriate cell size according to the application, and codes corresponding to the plurality of applications can be mixed.
[0015]
In the two-dimensional code reading method according to the present invention, first, a two-dimensional code image is obtained by scanning the two-dimensional code, and a two-dimensional code positioning process for detecting the position of the positioning symbol in the image is performed. . Next, cell positioning processing is performed to detect the position of at least one of the first information and second information in the two-dimensional code based on the position of the positioning symbol and the cell size of each information. . Next, based on the data cell from which the position has been detected, a decoding process for reading at least one of the first information and the second information is performed.
[0016]
In this way, with respect to a plurality of pieces of code information included in the two-dimensional code, one of them can be distinguished and either one can be read or both can be read. Therefore, for example, when an article with a label printed with this two-dimensional code is read at a high speed, the first cell expressed using a cell having the same cell size as the cell constituting the positioning symbol is used. When reading only information and reading the article while moving or stopped at low speed, only the second information expressed using a cell having a smaller cell size than the cells constituting the positioning symbol may be read. it can.
[0017]
When the second information in the two-dimensional code to be read is a plurality of types of information expressed using cells having different cell sizes, the following two-dimensional code is used. A reading method may be adopted.
That is, as shown in claim 3, in the cell positioning process, the position of at least one data cell of each information of a plurality of cell sizes constituting the first information or the second information in the two-dimensional code is determined. The detection is performed based on the position of the positioning symbol and the cell size of each information. In the decoding process, based on the data cell in which the position is detected, at least one of the pieces of information of the plurality of cell sizes constituting the first information and the second information is read. is there.
[0018]
For example, the second information is represented by information A expressed using a cell size smaller than the cell size of the first information and information B expressed using a cell size smaller than the cell size of the information A. When configured, the first information can be read at high speed, the information A of the second information can be read at a medium speed, and the information B can be read at a low speed or when stopped. Of course, there are three or more types, such as information C expressed using a cell size smaller than the cell size of information B, information D expressed using a cell size smaller than the cell size of information C, and so on. The same applies to the case where the second information is composed of the information. That is, only arbitrary information can be read out of three or more types of information.
[0019]
The cell size corresponding to the second information may be set at a ratio based on the cell size corresponding to the positioning symbol. For example, it is conceivable to set 1 / n (n is a natural number) such as 1/2, 1/3, 1/4,. Of course, a ratio such as n / m (m and n are natural numbers, where m> n) may be used. Further, it may be a fractional multiple instead of a fractional multiple. Since the position and shape of the positioning symbol are first determined, the cell size of the first information and the second information can be quickly and easily determined by the ratio in the cell positioning process based on the shape of the positioning symbol. Can be identified.
[0020]
If the positioning symbol is a pattern that obtains a specific frequency component ratio when scanned in a plurality of different directions or a plurality of different positions, the positioning symbol can be detected quickly by scanning, so that the two-dimensional code positioning is performed. As a result, the two-dimensional code can be read quickly.
[0021]
Further, the first information in the two-dimensional code to be read is expressed by a code using a code type corresponding to the positioning symbol, and the second information uses a code type different from the first information. If it is expressed in a code, the following two-dimensional code reading method may be adopted.
[0022]
That is, as shown in claim 4, in the decoding process, the code information is read using a decoding algorithm corresponding to the code type used for the information to be decoded. For example, even if the same matrix type two-dimensional code is used, “QR code”, “CP code”, “Carla code” or “Veri code” (These are registered trademarks) There are multiple code types, and the algorithms for decoding each are naturally different. Accordingly, each code information can be read by using a decoding algorithm corresponding to the code type used for each of the first information and the second information.
[0023]
The second information is composed of a plurality of types of information using cells having different cell sizes, and each information constituting the second information is different from a code using a code type different from the first information. The present invention can be similarly applied to a case where a two-dimensional code is expressed by a code using a code type, and each information is expressed by a code using a different code type. That is, in the decoding process, the code information is read using a decoding algorithm corresponding to the code type used for the information to be decoded among the information constituting the first information and the second information.
[0024]
Further, when the two-dimensional code to be read is further arranged at a predetermined position with respect to the positioning symbol and has a format code that can specify the existence area and the cell size for each piece of information in the two-dimensional code The following two-dimensional code reading method may be employed.
[0025]
That is, as shown in claim 6, after performing the two-dimensional code positioning process, the format code is detected based on the detected position of the positioning symbol, and the format of the two-dimensional code represented by the format code is acquired. Perform format acquisition processing. In the cell positioning process, the position of the data cell is detected based on the acquired two-dimensional code format. That is, since the format code can specify the existence area and the cell size for each piece of information in the two-dimensional code, the position of the data cell constituting the first information and the data cell constituting the second information Can be detected individually. Therefore, first, only information can be decoded, only second information can be decoded, and of course both can be decoded.
[0026]
Note that this format code may be represented by, for example, a cell distribution pattern in the same manner as a data cell representing information of a two-dimensional code. If expressed in this way, the format code can be easily detected.
By the way, such a two-dimensional code format is not necessarily required when only a two-dimensional code having the same format is to be read. That is, it is sufficient to prepare only a dedicated decoding algorithm for reading the two-dimensional code of the specific format. However, when a two-dimensional code expressed in a plurality of formats is to be read, it is preferable to directly acquire the format of the two-dimensional code to be read from the two-dimensional code at that time. Therefore, in this reading method, when reading the two-dimensional code, the format code is read from the two-dimensional code, and the first information and the second information existing area and the cell size are grasped in the two-dimensional code to be decoded. And decipher based on it.
[0027]
Further, the code type used for the first information is different from the code type used for the second information, and the format code is used code in addition to the existence area and the cell size for each of the information. When a two-dimensional code whose type can be specified is to be read, the following two-dimensional code reading method may be employed.
[0028]
That is, as shown in claim 7, after performing the two-dimensional code positioning process, the format code is detected based on the detected position of the positioning symbol, and the format of the two-dimensional code represented by the format code is acquired. A format acquisition process is performed, and as a cell positioning process, the position of the data cell is detected based on the acquired two-dimensional code format. In the decoding process, a decoding algorithm corresponding to the code type is specified based on the acquired two-dimensional code format, and the code information is read using the specified decoding algorithm.
[0029]
The format code may directly indicate the existence area, cell size, or used code type of the first and second information, or may indicate indirectly. In other words, for example, data type classification is performed according to differences in the existence area, cell size, use code type, etc., and only the information indicating the classification is used as a format code, and the correspondence between the classification information and the existence area, use code type, cell size The reader itself that realizes the reading method itself holds it.
[0030]
Further, the two-dimensional code is arranged at a position different from the positioning symbol in the two-dimensional code, and includes an auxiliary symbol whose position is detected based on the position of the positioning symbol and its own pattern. In such a case, a reading method as shown in claim 8 may be adopted. That is, after performing the two-dimensional code positioning process, the auxiliary symbol positioning process for detecting the position of the auxiliary symbol in the image is performed based on the detected position of the positioning symbol and the pattern of the auxiliary symbol. In the cell positioning process, the position of the data cell is detected based on the auxiliary symbol.
[0031]
As described above, in the cell positioning process, not only the positioning symbols but also the auxiliary symbols are used, and the positioning symbols or the positions of the auxiliary symbols in the vicinity of the data cell are used. Therefore, even if the two-dimensional code is distorted, the positioning is performed. As compared with the case where the data cell is positioned based only on the reference symbol, the data cell is positioned accurately. For example, in the cell positioning process, if the position of a positioning cell or a data cell around the auxiliary symbol is detected based on the shape of each positioning symbol and each auxiliary symbol, the distortion of the two-dimensional code is Since it is reflected in the shapes of the positioning symbol and the auxiliary symbol, the distortion of the two-dimensional code is reflected in the positioning of the data cell, and the positioning of the data cell can be performed accurately.
[0032]
In addition, since the auxiliary symbol is not used as a reference for positioning the two-dimensional code first like the positioning symbol, the two-dimensional code positioning process itself can be performed quickly without increasing the processing amount. It can be carried out. Note that it is preferable that the auxiliary symbol be formed smaller than the positioning symbol because the area of the data cell can be secured as much as that. Even if the auxiliary symbol does not use a pattern as large as the positioning symbol for positioning the two-dimensional code, the position of the two-dimensional code is already determined by the positioning symbol. The position can be determined.
[0033]
Furthermore, although it has been described above that the positioning symbol is a pattern that can obtain a specific frequency component ratio when scanned in a plurality of different directions or in a plurality of different positions, the auxiliary symbol is also a plurality of different symbols. It may be a pattern in which a specific frequency component ratio is obtained when scanning in a direction or a plurality of different positions, and after detecting a positioning symbol, an auxiliary symbol detection process can be performed quickly, so that a two-dimensional code can be quickly Preferred for reading.
[0034]
By the way, in the description so far, it was assumed that the cell size used for expressing the information is different, but both the first information and the second information are two-dimensional codes that express the information by the cell distribution pattern. Met. On the other hand, a positioning symbol for specifying the position of the two-dimensional code is provided at a predetermined position in the two-dimensional code that expresses information by the cell distribution pattern, and the code type corresponding to the positioning symbol is used When the first information expressed by the two-dimensional code and the second information expressed by the barcode are each read as a two-dimensional code arranged at a predetermined position in the two-dimensional code The following two-dimensional code reading method may be employed.
[0035]
That is, as shown in claim 9, first, an image of a two-dimensional code is obtained, and a two-dimensional code positioning process for detecting the position of the positioning symbol in the image is performed. Next, the position of at least one of the data cell for expressing the first information and the bar for expressing the second information in the two-dimensional code is detected based on the position of the positioning symbol. Performs cell positioning processing. Next, at least one of the decoding process of the code information of the first information based on the data cell where the position is detected or the reading of the code information of the second information based on the bar where the position is detected is performed.
[0036]
In this way, the first information consisting of “two-dimensional code” in which cells are arranged two-dimensionally and the second information consisting of “barcode” in which bars are arranged one-dimensionally are mixed. However, it is possible to freely read only the first information, only the second information, or both. Of course, firstly, the decryption algorithm differs between the information and the second information.
[0037]
In this case as well, when only the two-dimensional code of the same format is to be read, it is sufficient to prepare only a dedicated decoding algorithm for reading the two-dimensional code of the specific format. When the two-dimensional code to be expressed is a reading target, it is preferable that the format of the two-dimensional code to be read is directly acquired from the two-dimensional code at that time. Therefore, as shown in claim 10, the two-dimensional code is further arranged at a predetermined position with respect to the positioning symbol, and the format code that can specify the existence area and the used code type for each piece of information in the two-dimensional code. If it is equipped with, the following reading method should be adopted
That is, after the two-dimensional code positioning process is performed, a format code is detected based on the detected position of the positioning symbol, and a format acquisition process for acquiring the format of the two-dimensional code represented by the format code is performed. As the cell positioning process, at least one of a data cell for expressing the first information and a bar for expressing the second information based on the acquired two-dimensional code format. Detect position. In the decoding process, a decoding algorithm corresponding to the code type is specified based on the acquired two-dimensional code format, and code information is read using the specified decoding algorithm.
[0038]
Note that the function of executing such a two-dimensional code reading method is provided as a program activated on the digital circuit or computer system side, for example. When it is realized by a program, for example, flexible It can be stored in a machine-readable recording medium such as a disk, a magneto-optical disk, a CD-ROM, or a hard disk, and can be used by being loaded into a computer system and started up as necessary. In addition, the ROM or backup RAM may be stored as a machine-readable recording medium, and the program may be stored, and the ROM or backup RAM may be incorporated into a computer system.
[0039]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments to which the present invention is applied will be described below with reference to the drawings. Needless to say, the embodiments of the present invention are not limited to the following examples, and can take various forms as long as they belong to the technical scope of the present invention.
[0040]
The block diagram of FIG. 1 shows a schematic configuration of a two-dimensional code reader 2 to which the above-described invention is applied.
The two-dimensional code reader 2 includes a CCD 4, a binarization circuit 6, an image memory 8, a clock signal output circuit 14, an address generation circuit 16, a change point detection circuit 18, a ratio detection circuit 20, an address storage memory 22, and a control circuit 28. It is composed of
[0041]
The control circuit 28 is configured as a computer system including a CPU, a ROM, a RAM, an I / O, and the like, and executes a two-dimensional code reading process, which will be described later, according to a program stored in the ROM. 2 is controlled.
[0042]
Here, a schematic diagram of an example of a two-dimensional code detected by the two-dimensional code reader 2 is shown in FIG. The two-dimensional code 52 is printed on a white mount 53, and includes three positioning symbols 54A, 54B and 54C, a data area 56, one auxiliary symbol 60, timing cells 20a and 20b, and a format code. 70 or the like.
[0043]
In this embodiment, the data area 56 is divided into a first data area Aa and a second data area Ab, and the cell sizes of the data cells used in both the data areas Aa and Ab are different. Specifically, the cell size of the data cell used in the first data area Aa is a so-called “quadrature cell” that is twice as long as the cell size of the data cell used in the second data area Ab. Has been. In FIG. 2, each of the first data area Aa and the second data area Ab is divided into cell groups each composed of a total of 8 cells of 2 cells × 4 cells. This is because when one cell is considered to be 1 bit, one byte can be indicated by one cell group, and setting in such a unit is convenient for data processing after reading.
[0044]
Accordingly, in practice, one square cell in FIG. 2B showing one cell group of the first data area Aa indicates the cell size of the data cell used in the first data area Aa. Yes. Similarly, one square cell in FIG. 2C showing one cell group of the second data area Ab indicates the cell size of the data cell used in the second data area Ab. And what is expressed by the data cell of the first data area Aa is “first information”, and the second data area Ab. of What is expressed by a data cell is “second information”.
[0045]
The size of the entire two-dimensional code 52 is a square shape of 29 cells × 29 cells with reference to the data cells used in the first data area Aa. Of course, if the data cell used in the second data area Ab is used as a reference, it is expressed as 58 cells × 58 cells, but in this embodiment, it is used in the first data area Aa unless otherwise required. A description will be given with reference to a data cell.
[0046]
Each cell in the data area 56 is selected from two types of optically different cells, and are distinguished from each other by white (bright) and black (dark) in the drawings and description. In FIG. 2, the black and white pattern of the data cell in the data area 56 is omitted for convenience. Of course, in each of the first data area Aa and the second data area Ab, light and dark are distinguished by the unit of the data cell used in each data area Aa, Ab (see FIGS. 2B and 2C). ing.
[0047]
Three positioning symbols 54A, 54B, and 54C are arranged at three of the four vertices of the two-dimensional code 52, and the data cells have the same cell size as that used in the first data area Aa. Configured. From a technical point of view, it is appropriate to consider that data cells having the same cell size as the cells constituting the positioning symbols 54A, 54B, 54C are used in the first data area Aa. Therefore, in the second data area Ab, data cells having a cell size that is a quarter of the cells constituting the positioning symbols 54A, 54B, and 54C are used.
[0048]
As shown in FIG. 3 (A), the light and dark arrangement of the cells of the positioning symbols 54A, 54B, and 54C is composed of a white portion having a width of 1 cell at a central portion in a frame-shaped square 55a composed of a black portion having a width of 1 cell. This is a pattern in which a reduced frame-like square 55b is formed, and a square 55c having a size of 3 cells × 3 cells consisting of a black portion is formed in the central portion inside.
[0049]
As can be seen from FIG. 2, the first data area Aa is arranged between the positioning symbols 54A, 54B, 54C, while the second data area Ab is the other part (right in FIG. 2A). (Lower part).
Further, as shown in FIG. 2, the auxiliary symbol 60 is arranged in the second data area Ab, but is composed of data cells having the same cell size as that used in the first data area Aa. ing. As shown in FIG. 3 (C), the light and dark arrangement of the cells of the auxiliary symbol 60 is a reduced frame-shaped square made up of a white portion with a width of 1 cell at the center of the frame-like square 61a made up of a black portion with a width of 1 cell. 61b is formed, and a square 61c composed of a black portion of one cell is formed in the central portion inside thereof.
[0050]
On the other hand, the timing cells 20a and 20b are arranged between the positioning symbols 54A, 54B and 54C, and are composed of data cells having the same cell size as that used in the first data area Aa. The timing cells 20a and 20b are used as a reference pattern serving as an index of each data cell position in which white and black are alternately combined.
[0051]
The format code 70 is arranged in the vicinity of the positioning symbol 54A, and is composed of data cells having the same cell size as that used in the first data area Aa. The format code 70 has contents that can specify at least one of the existence area, the code type used, and the cell size for each of the first and second information.
[0052]
In this case, the format code 70 may directly indicate the existence area, the used code type, and the cell size for each of the first and second information, or may indicate indirectly. . That is, for example, the data type classification may be performed according to the difference in the existence area, the use code type, the cell size, and the like, and only the information (for example, numbers) indicating the classification may be included as the format code. In this case, for example, the correspondence between the classification information and the existing area, the used code type, the cell size, etc. is stored in a table, for example, in the RAM or the like in the control circuit 28 of the two-dimensional code reader 2. I can deal with it.
[0053]
The control circuit 28 performs reading control as described below.
First, in accordance with an instruction from the control circuit 28, a two-dimensional image of a place where the two-dimensional code 52 passes is detected by the CCD 4. When the CCD 4 detects a two-dimensional image, the CCD 4 outputs two-dimensional image data with a signal composed of multiple levels as shown in FIG. The two-dimensional image data is binarized by the binarization circuit 6 at the threshold value designated by the control circuit 28, and two levels of 1 (high) / 0 (low) as shown in FIG. Convert to a signal consisting of
[0054]
On the other hand, the clock signal output circuit 14 outputs a clock pulse sufficiently finer than the pulse of the two-dimensional image data output from the CCD 4 according to the synchronization pulse output from the CCD 4. The address generation circuit 16 counts the clock pulses and generates an address for the image memory 8. The binarized two-dimensional image data is written in units of 8 bits for each address.
[0055]
On the other hand, the change point detection circuit 18 outputs a pulse signal to the ratio detection circuit 20 when the signal from the binarization circuit 6 changes from “1” to “0” or from “0” to “1”. To do. The ratio detection circuit 20 counts the clock pulses output from the clock signal output circuit 14 from the input of the pulse signal from the change point detection circuit 18 to the input of the next pulse signal, thereby bright (1) in the two-dimensional image. ) And the continuous length of dark (0). A pattern corresponding to the positioning symbols 54A, 54B, 54C of the two-dimensional code 52 is detected from this length ratio.
[0056]
As shown in FIG. 3A, the light and dark patterns on the scanning lines (a), (b), and (c) of the CCD 4 crossing substantially the centers of the positioning symbols 54A, 54B, and 54C at typical angles are shown in FIG. As shown in FIG. 3B, all have the same light / dark component ratio. That is, the light / dark component ratio of each scanning line (a), (b), (c) crossing the center of the positioning symbols 54A, 54B, 54C is dark: bright: dark: light: dark = 1: 1: 3: 1: 1. Of course, the ratio is 1: 1: 3: 1: 1 even in the scanning line having an intermediate angle between the scanning lines (a), (b), and (c). 3A is arranged on an oblique surface when viewed from the CCD 4 side, the light / dark component ratio of the scanning lines (a), (b), and (c) is dark: bright: Dark: light: dark = 1: 1: 3: 1: 1. FIG. 3B corresponds to the binarized signal from the binarization circuit 6.
As a result, the ratio detection circuit 20 detects the light / dark component ratio of “1: 1: 3: 1: 1”, and if detected, the image memory generated by the address generation circuit 16 at that timing. 8 addresses are stored in the address storage memory 22.
[0057]
Therefore, when the CCD 4 detects two-dimensional image data for one frame, the image memory 8 stores the binarized two-dimensional image data, and the address storage memory 22 stores the detected positioning symbols. The addresses 54A, 54B and 54C are stored.
[0058]
When an image for one frame of the first two-dimensional image is obtained, the control circuit 28 performs a two-dimensional code reading process, which will be described later, based on the data in the image memory 8 and the address storage memory 22, and this process is completed. Then, the control circuit 28 instructs the CCD 4 to detect the next one-frame two-dimensional image. Therefore, the two-dimensional image is output from the CCD 4 to the binarization circuit 6 again, and the processing as described above is repeated.
[0059]
Next, the image of the two-dimensional code 52 for one frame and the addresses of the positioning symbols 54A, 54B, 54C are stored in the image memory 8 and the address storage memory 22, respectively. Execute code reading process. This two-dimensional code reading process is shown in the flowcharts of FIGS.
[0060]
When the processing is started, first, detection processing of the positioning symbols 54A, 54B, 54C is performed (S100).
In this process, the image memory 8 and the address storage memory 22 are accessed, and from the stored contents, it is determined whether or not three positioning symbols 54A, 54B, 54C are present at appropriate positions, and the positioning symbols. An accurate shape and center position on the images of 54A, 54B, and 54C are determined.
[0061]
In this processing, first, whether the addresses of the positioning symbols 54A, 54B, 54C detected in the address memory 22 are divided into three groups in position is referred to the address value and the image in the image memory 8. While judging. Further, the shape and center position of each positioning symbol 54A, 54B, 54C are determined from the 1 (white) / 0 (black) pattern of the image in the image memory 8, and three of them are 3 as shown in FIG. It is determined whether or not the arrangement state exists at one vertex.
[0062]
Next, in step S100, it is determined whether or not three appropriate positioning symbols 54A, 54B, 54C have been detected (S120). If not detected (“NO” in S110), the next image is detected. Is instructed to the CCD 4 (S280 in FIG. 6), and the process ends.
[0063]
When appropriate three positioning symbols 54A, 54B, and 54C are detected (“YES” in S110), it is next determined whether or not the new two-dimensional code 52 is used (S120). This process is to prevent the two-dimensional code 52 detected before the previous time from being decoded as another two-dimensional code when it is still being detected by the CCD 4. For example, if the appropriate three positioning symbols 54A, 54B, 54C have been detected in the previous processing or the previous processing a predetermined number of times, and the code contents have already been properly read, the same two-dimensional code 52 is detected (“NO” in S120), the CCD 4 is instructed to detect the next image (S280), and the process ends.
[0064]
If it is determined that the code is the new two-dimensional code 52 (“YES” in S120), the shape of each cell constituting each of the positioning symbols 54A, 54B, 54C is then determined according to the shape of the positioning symbols 54A, 54B, 54C. The center position is calculated (S130).
[0065]
That is, for the positioning symbols 54A, 54B, and 54C, as shown in FIGS. 2 and 3A, the width of the black frame-shaped square 55a is one cell, and the width of the white frame-shaped square 55b is one cell. Since the width of one cell and the black square 55c is three cells, the height and width of the positioning symbols 54A, 54B and 54C in the image memory 8 are determined from the height and width. By dividing by 7 respectively, three cell height and width values at the positions of the positioning symbols 54A, 54B, 54C, that is, three cell shapes are obtained.
[0066]
Next, based on the cell heights and widths of the positioning symbols 54A, 54B, and 54C determined in this way, the cell positions of the positioning symbols 54A, 54B, and 54C are determined.
Next, the format code 70 is detected based on the positioning symbol 54A (S140). This format code 70 corresponds to one cell with respect to the side facing the positioning symbol 54B out of the four sides constituting the outermost frame square 55a (see FIG. 3A) of the positioning symbol 54A. They are spaced apart in parallel. Therefore, based on this relationship, the position of the format code 70 can be known and the code can be detected.
[0067]
Next, it is determined whether or not the first information is to be decoded (S150), and if it is to be decoded (“YES” in S150), the code of the first information is decoded (S160).
Details of the decoding process of the first information code in S160 will be described with reference to the flowchart of FIG.
[0068]
When this processing routine starts, first, based on the format code 70 detected in S140 of FIG. 5, the location of the first data area Aa in the two-dimensional code 52 and the cell size of the data cell contained therein Is specified (S161). The format code 70 in this case is information indicating the classification when the data type is classified according to the difference in the location (existing area) of each data area and the cell size of the data cell included in the data area. (For example, a number) is encoded. That is, in this case, the correspondence relationship between the classification information and the existing area / cell size is stored in a table in, for example, the RAM in the control circuit 28 of the two-dimensional code reader 2. Therefore, in S161, the existence area and the cell size are specified with reference to the correspondence table.
[0069]
Next, based on the existence area and cell size specified in S161 and the shapes and center positions of the positioning symbols 54A, 54B, and 54C detected in S130 of FIG. The center position of the cell is determined (S162).
Then, binary values are read from the pixel at the center position of each data cell, the type of each cell is determined, and the code contents are obtained (S163). That is, a decoding process is performed. At the time of decoding in S163, processing based on the format information obtained from the format code 70 is executed as necessary. For example, in the first data area Aa, the arrangement pattern of the cell groups indicated by being divided into 2 cells × 4 cells is not necessarily aligned. For example, the cell group between the positioning symbols 54A and 54B is vertically long. Are horizontally long, and the cell group between the positioning symbols 54A and 54C is only vertically long. Therefore, format information for specifying such a cell group arrangement pattern or the like is obtained from the format code 70 and decoded based on the format information.
[0070]
In this way, the information represented by the code of the first information is obtained, this processing routine is terminated, the process returns to the main routine, and the process proceeds to S170 in FIG.
In S170, it is determined whether or not the code content is normal. For example, whether or not the number of white and black cells is a predetermined number, or the result of calculating the data represented by a predetermined calculation method is within a predetermined range in the two-dimensional code 52 Whether or not the code is normally read is determined based on whether or not it matches the displayed check data.
[0071]
If it is a normal code (“YES” in S170), it is determined whether or not the first information is output (S180). If it is output (“YES” in S180), the code contents are stored in the host computer. Processing to output to other devices such as, store the code content in a specific memory, execute processing corresponding to the code content, or output an instruction corresponding to the code content (hereinafter referred to as the code content) The process is called “code content output process” (S260). Thereafter, the CCD 4 is instructed to detect the next image (S280), and the process ends.
[0072]
On the other hand, as a result of decoding the first information, if the code is not normal (“NO” in S170), the process proceeds to S190. Note that if the determination in S150 is negative, that is, if it is determined not to decode the first information, the process also proceeds to S190. In S190, it is determined whether or not the second information is to be decoded. If the second information is not decoded (“NO” in S190), the CCD 4 is instructed to detect the next image (S280), and the process is performed. finish.
[0073]
On the other hand, when the second information is decoded (“YES” in S190), the process proceeds to S200, and the code of the second information is decoded. Note that if it is determined negative in S180, that is, if it is determined not to output the first information, the process proceeds to S200, and the code of the second information is decoded.
[0074]
Details of the decoding process of the second information code in S200 will be described with reference to the flowchart of FIG.
When this processing routine starts, first, based on the format code 70 detected in S140 of FIG. 5, the location of the second data area Ab in the two-dimensional code 52 and the cell size of the data cell contained therein Is identified (S201). Since this content is the same as that of S161 in FIG. 7 described above, it will not be repeated.
[0075]
Next, as described above (S130 of FIG. 5), the positioning symbols 54A, 54B, and 54B are obtained as described above (S130 in FIG. 5) by using the center positions of the auxiliary symbols 60 arranged at predetermined positions with respect to the positioning symbols 54A, 54B, and 54C. It is obtained by calculation based on the shape and center position of the cells constituting 54C, and further, the shape and position are accurately determined by examining the image around the calculation position (S202).
[0076]
As shown in FIG. 3D, the light / dark component ratio of each straight line (a), (b), (c) crossing the center of the auxiliary symbol 60 is dark: bright: dark: bright: dark = 1: 1. The property of 1: 1: 1: 1 is essentially the same as the positioning symbols 54A, 54B, and 54C shown in FIGS.
[0077]
Then, the shape and center position of each cell constituting the auxiliary symbol 60 are determined for the auxiliary symbol 60 for which the accurate shape and the accurate center position are determined in this way (S203).
Next, based on the existence area and cell size specified in S201, the shapes and center positions of the positioning symbols 54A, 54B, and 54C detected in S130 of FIG. The center position of each data cell in the data area Ab is determined (S204).
[0078]
Then, binary values are read from the pixel at the center position of each data cell, the type of each cell is determined, and the code contents are obtained (S205). In this way, information represented by the code of the second information is obtained, this processing routine is terminated, the process returns to the main routine, and the process proceeds to S210 in FIG.
[0079]
In S210, it is determined whether or not the code content is normal. This is the same as the determination in S170 described above.
If it is a normal code (“YES” in S210), it is determined whether there is decoded first information data (S220), and if there is first information data (“YES” in S220). Further, it is determined whether only the second information is decoded and output (S230). If only the second information is not decoded and output (“NO” in S230), processing such as code content output is performed on the decoded first and second information (S240). On the other hand, when a negative determination is made in S220, that is, when the first information is not decoded, or when a negative determination is made in S230, that is, when only the second information is output, the process proceeds to S270 and the decoded second information Only the code content output process is performed.
[0080]
If the negative determination is made in S210, that is, if the decoded code content of the second information is not normal, it is determined whether there is data of the first information (S250). If there is data of the first information (“YES” in S250), processing such as code content output is performed only for the decoded first information (S260), while there is no data of the first information (S260). If “NO” in S250), the process proceeds to S280 without performing the code content output process or the like.
[0081]
Thus, in the two-dimensional code reader 2 of the present embodiment, the “first information” and the second data area Ab included in the first data area Aa constituting the data area 56 of the two-dimensional code 52. One of the “second information” included therein can be distinguished and read, or both can be read. Therefore, for example, when an article with a label printed with the two-dimensional code 52 is read at a high speed, a cell having the same cell size as the cells constituting the positioning symbols 54A, 54B, and 54C is used. When only the first information in the expressed first data area Aa is read and the article is read in a state where the article is moving at low speed or stopped, the second data expressed using a cell having a quarter cell size. It is also possible to read only the second information in the area Ab.
[0082]
By realizing such a two-dimensional code reading device 2, the two-dimensional code 52 to be read can be formed with an appropriate cell size according to the application, and the codes corresponding to the plurality of applications can be formed. Can be mixed. Therefore, as in the prior art, a label printed with a two-dimensional code having a relatively large cell size for reading during high-speed movement, and a label printed with a two-dimensional code having a relatively small cell size for a hand-held reader Thus, it is not necessary to prepare two types of labels and attach them to the articles, and only one label is sufficient. And even if the data to be read at the time of high-speed movement and the data to be read by a hand-held reader are mixed in the same code, it is possible to prevent the two-dimensional code from becoming larger than necessary as in the prior art. . This is because the cell size when reading data for high-speed movement should be the minimum size that can be read during high-speed movement, while the cell size for reading data with a hand-held reading device. This is because the size can be set to a minimum size that can be read in a stopped state. That is, it is not necessary to match the larger cell size, and the code can be formed with a cell size as small as possible according to the application, so that the two-dimensional code 52 itself can be made as small as possible.
[0083]
The auxiliary symbol 60 is also used for decoding the code in the second data area Ab. As a result, even if the image of the two-dimensional code 52 is distorted, the data cell is positioned more accurately than when only the positioning symbols 54A, 54B, and 54C are used. Therefore, the information represented by the data cell can be read accurately. Further, the auxiliary symbol 60 is not used as a reference for positioning the two-dimensional code 52 first, like the positioning symbols 54A, 54B, and 54C. It can be done quickly without increasing.
[0084]
As the two-dimensional code 52 to be read, as shown in FIG. 2A, the two-dimensional code 52 having a size of 29 cells × 29 cells when the data cell used for the first data area Aa is used as a reference. As described above, the two-dimensional code 52 having a different overall cell size can be realized as a target. For example, the two-dimensional code shown in FIG. 9A is 21 cells × 21 cells (42 cells × 42 cells when the data cell used for the second data area Ab is used as a reference). The two-dimensional code shown is 25 cells × 25 cells (50 cells × 50 cells when the data cell used for the second data area Ab is used as a reference). In either case, the first data area Aa is arranged between the positioning symbols 54A, 54B, 54C, and the second data area Ab is arranged in the other part (lower right part in FIG. 9). Is the same. Therefore, the total number of data cells in the first data area Aa for expressing “first information” and the total number of data cells in the second data area Ab for expressing “second information” are shown in FIG. In the case shown in a), the case shown in FIG. 9B decreases in the order shown in FIG. 9A.
[0085]
In the case shown in FIG. 9B, the auxiliary symbol 60 is added, but in the case shown in FIG. 9A, the auxiliary symbol 60 is not added. With this size, reading error due to the influence of distortion is small, so that reading can be performed accurately even without adding the auxiliary symbol 60. Of course, the auxiliary symbol 60 may not be provided in the case shown in FIG. 9B or the case shown in FIG. Although FIG. 9 shows a case where the overall size is smaller than the case shown in FIG. 2A, a large size can also be realized. When the overall sizes are different as described above, the arrangement of the cell groups shown by being divided into 2 cells × 4 cells in the first data area Aa is also slightly different. Therefore, in order to distinguish between these differences, version information 80 indicating which version is present is arranged adjacent to the data cell in the first data area Aa between the positioning symbols 54A and 54B. Therefore, in the decoding process of the first information code executed in S160 of FIG. 6, the version information 80 is first decoded, and the decoding is performed after knowing the arrangement pattern of the cell group in the first data area Aa. Can be done.
[0086]
In this embodiment, the CCD 4, the binarization circuit 6, the clock signal output circuit 14, the processing performed by the address generation circuit 16, the change point detection circuit 18 and the ratio detection circuit 20 at the timing, and steps S100 and S121 performed by the control circuit 28, Corresponds to the two-dimensional code positioning process, and step S140 corresponds to the format acquisition process. Step S202 corresponds to the auxiliary symbol positioning process. In the case of FIG. 7, step S162 corresponds to the cell positioning process. In the case of FIG. 8, steps S203 and S204 correspond to the cell positioning process. In the case of FIG. 7, step S163 corresponds to the decoding process, and in the case of FIG. 8, step S205 corresponds to the decoding process.
[0087]
[Another embodiment]
In the two-dimensional code 52 to be read in the above embodiment, as shown in FIG. 2, the first data area Aa is arranged between the positioning symbols 54A, 54B, 54C, while the second data area Ab is It was arranged in the part other than. That is, the data area 56 is divided and each area is set as a two-dimensionally continuous area. On the other hand, for example, as shown in FIG. 10, the two-dimensional code 152 in which the first data area Aa is arranged in a scattered manner throughout the data area 156 and the other areas are set as the second data area Ab. Can be read. For example, in the decoding process of the first information code shown in S160 of FIG. 5, a binary value (0 or 1) at the center position of the data cell corresponding to the first data area Aa arranged in a scattered manner. Therefore, the same data processing is possible even with such a scattered arrangement.
[0088]
Further, even in the case where the areas are divided and set as in the case of FIG. 2, the first data area Aa is not necessarily arranged between the positioning symbols 54A, 54B, and 54C. For example, the first data area Aa may be set only between the positioning symbol 54A and the positioning symbol 54B, or the second data area Ab may be disposed between the positioning symbols 54A, 54B, and 54C. Good.
[0089]
In the description so far, the “second information” is expressed using data cells having a cell size that is a quarter of the cell size of the positioning symbols 54A, 54B, and 54C. That is, it is assumed that the sizes of the data cells for indicating the “second information” are all equal, but this “second information” is a collection of a plurality of types of information and cells having different cell sizes. It may be expressed using. For example, as shown in FIG. 11, four types of information may be configured in the “second information”, and a two-dimensional code 252 that has a total of five types of cell sizes may be read.
[0090]
In the example of FIG. 11, positioning symbols 254A, 254B, 254C, and 254D are arranged at four vertices of the two-dimensional code 252, and the first data area Aa between the positioning symbols 254A and 254B is the same as the above example. Data cells having the same cell size as positioning symbols 254A, 254B, 254C, and 254D, that is, (1/1) are arranged. Further, in the second data area Ab between the positioning symbols 254A and 254C, data cells having a cell size (1/2) of the positioning symbols 254A, 254B, 254C, and 254D are arranged, and the positioning symbols 254C, 254C, In the third data area Ac between 254D, data cells having a cell size (1/3) of the positioning symbols 254A, 254B, 254C, and 254D are arranged. In the fourth data area Ad between the positioning symbols 254B and 254D, data cells having a cell size (1/4) of the positioning symbols 254A, 254B, 254C, and 254D are arranged, and the other fifth data areas Ad are arranged. In the data area Ae (a predetermined area at the center of the two-dimensional code 252), data cells having a cell size (1/5) of the positioning symbols 254A, 254B, 254C, and 254D are arranged.
[0091]
In the case of FIG. 11, 1 / n (where n is 1 / n, such as 1/2, 1/3, 1/4,..., With reference to cell sizes corresponding to the positioning symbols 254A, 254B, 254C, 254D. Natural number) is set, but of course, a ratio such as n / m (m and n are natural numbers, where m> n) may be used. However, n is a natural number (1/2 ⁿ ) Is preferable for processing the read data in the computer system. Note that it may be a fractional multiple instead of a fractional multiple.
[0092]
Even when such a two-dimensional code 252 is read, the basic processing contents are the same as those shown in FIGS. In the case of FIGS. 5 to 8, the two-dimensional code 52 having only two types of data areas is premised. However, since there are five types of the two-dimensional code 252 shown in FIG. 11, it is determined whether or not to decode each of them. When decoding, the cell position corresponding to the data area is similarly taken into consideration, the center position of each data cell in the data area is determined, and the binary value is read from the pixel at the center position to read the cell. The code content can be obtained by determining the type of.
[0093]
As described above, various area settings and data arrangements can be considered. If information that can identify these is set in the above-described format code 70 (see FIG. 2), the format code 70 is read in S140 of FIG. By executing the decoding process based on the format code 70, various variations can be dealt with. However, this format code 70 is not necessarily required in certain limited situations. That is, it is not necessary when only two-dimensional codes having the same format are used. This is because it is sufficient to prepare a dedicated program for reading the two-dimensional code of the specific format. However, when reading a two-dimensional code expressed in a plurality of formats, it is preferable that the format itself of the two-dimensional code to be read can be directly acquired from the two-dimensional code at that time. Therefore, it is preferable to include a format code 70 in the two-dimensional code 52 as shown in FIG.
[0094]
The version information 80 described above may be considered as a part of the format code 70 in a certain sense. That is, the cell group arrangement pattern of the data cells in the first data area Aa is different in the above-described example due to the difference in size between the first data area Aa and the second data area Ab. Therefore, although it is version information used to distinguish only this point, it is information related to the format in a large sense.
[0095]
By the way, in the above description, the case where the two-dimensional code is read on the premise that the first information and the second information are of the same code type has been described. That is, in the case of FIG. 2, the code type is a two-dimensional code of a so-called “QR code”. However, you must use the same code type. For example, as shown in FIG. 12, in the first data area Aa, “first information” is expressed by a QR code, and in the second data area Ab, for example, even if the same matrix type two-dimensional code is used, “ CP code, Carla code or Veri code (These are registered trademarks) The “second information” may be expressed by a code using a code type different from the QR code. In addition, as shown in FIG. 11, if there are five areas Aa to Ae, it is possible to arrange five different code types.
[0096]
In this case, for example, by referring to the format code 70, it is possible to know which code type contains code information in which data area. On the other hand, the two-dimensional code reader 2 is provided with a program for decoding processing by a decoding algorithm corresponding to the code type included in the two-dimensional code to be read. And when decoding the code | cord | chord of each data area, a decoding process should just be performed using a corresponding decoding algorithm.
[0097]
By the way, in the explanation so far, on the premise that the cell size used for the expression is different, both the first information and the second information are two-dimensional codes that express information by a cell distribution pattern. . On the other hand, for example, as shown in FIG. 13, in the first data area Aa, “first information” is expressed by a QR code, and in the second data area Ab, for example, “first information” is expressed by a barcode. 2 information "may be expressed. In FIG. 13, a bar code is arranged in the second data area Ab between the positioning symbols 54A and 54B. In this case, for example, the bar code can be decoded by making a light / dark judgment at a portion included in the second data area Ab within a straight line connecting the centers of the positioning symbols 54A to 54B. Of course, other methods may be used.
[0098]
In this case, for example, it is conceivable that the second information indicated by the barcode is used for store (storefront) management, and the first information indicated by the QR code is used for backyard management. In addition, when the code systems used in the first information and the second information are different, information that can be distinguished in the format code 70 described above may be inserted.
[0099]
[Others]
In the two-dimensional codes 52, 152, 252, 352, and 452 described as the reading target in each of the embodiments, for example, as shown in FIG. 2, the positioning symbols 54A to 54C are double squares, and the frequencies crossing the center. The component ratio is represented by a graphic of black: white: black: white: black = 1: 1: 3: 1: 1, and the auxiliary symbol 60 is represented by a similar graphic smaller in size than the positioning symbols 54A to 54C. As shown in FIG. 14A, it may be circular, as shown in FIG. 14B, hexagonal, or other regular polygon. That is, it is only necessary that the similar figures are concentrically overlapped, and the contents of the positioning symbol detection process performed in S100 of FIG. 5 are not changed. Furthermore, as long as the frequency component ratio across the center is the same at all angles, as shown in FIG. In this case, the processing for detecting the corresponding frequency component ratio is only the positioning symbol detection processing performed in S100 of FIG.
[0100]
Further, in each of the above embodiments, for example, as shown in FIG. 2, the outer shape of the two-dimensional code 52 to be read is shown as a square, but may be a rectangle. For example, as shown in FIG. 1, the positioning symbols 54 </ b> A to 54 </ b> C are arranged at three of the four vertices of the two-dimensional code 52, but the arrangement within the two-dimensional code 52 is arbitrary. . One two-dimensional code 52 may be provided with four or more positioning symbols.
[0101]
There may be two positioning symbols. In this case, if the positioning symbols are arranged at the two vertices on the diagonal, the arrangement of the two-dimensional code 52 is determined. Even when positioning symbols are arranged at two vertices other than the diagonal or other than the vertices, the arrangement of the data area 56 can be detected by detecting the pattern of the auxiliary symbol 60. If the detection of the pattern of the auxiliary symbol 60 is used in this way, the number of positioning symbols may be one. For example, one positioning symbol exists at the center of the two-dimensional code 52, and auxiliary symbols are arranged around it. The position of the data cell can be obtained even if the positioning symbol is arranged at any position in the two-dimensional code 52.
[0102]
In the above embodiment, the positioning symbols 54A to 54C are detected by the ratio detection circuit 20 in hardware and the auxiliary symbol 60 is detected in software. However, the auxiliary symbol 60 is also provided with a ratio detection circuit. It may be detected by hardware, and the processing becomes quicker. Of course, both the positioning symbols 54 </ b> A to 54 </ b> C and the auxiliary symbol 60 can be detected by software.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a schematic configuration of a two-dimensional code reader according to an embodiment.
FIG. 2 is a schematic configuration explanatory diagram of a two-dimensional code in the embodiment.
FIG. 3 is an explanatory diagram of light and dark detection when a positioning symbol and auxiliary symbols are scanned in an embodiment.
FIG. 4 is an explanatory diagram of output signals from a CCD and a binarization circuit in the embodiment.
FIG. 5 is a flowchart illustrating the first half of a two-dimensional code reading process in the embodiment.
FIG. 6 is a flowchart showing the second half of the two-dimensional code reading process in the embodiment.
FIG. 7 is a flowchart showing a first information code decoding process routine executed in the two-dimensional code reading process in the embodiment;
FIG. 8 is a flowchart illustrating a second information code decoding processing routine executed in the two-dimensional code reading processing in the embodiment;
FIG. 9 is an explanatory diagram of a schematic configuration of another version of a two-dimensional code in an embodiment.
FIG. 10 is an explanatory diagram of a schematic configuration of a two-dimensional code in another embodiment.
FIG. 11 is an explanatory diagram of a schematic configuration of a two-dimensional code in another embodiment.
FIG. 12 is a schematic configuration explanatory diagram of a two-dimensional code in another embodiment.
FIG. 13 is an explanatory diagram of a schematic configuration of a two-dimensional code in another embodiment.
FIG. 14 is an explanatory diagram illustrating an example of another shape of a positioning symbol.
FIG. 15 is an explanatory diagram of a conventional barcode and a two-dimensional code.
FIG. 16 is a schematic configuration explanatory diagram of a conventional two-dimensional code.
[Explanation of symbols]
2 ... Two-dimensional code reader 4 ... CCD
6 ... binarization circuit 8 ... image memory
14 ... Clock signal output circuit 16 ... Address generation circuit
18 ... change point detection circuit 20 ... ratio detection circuit
20a, 20b, 120a, 120b, 220a, 220b, 320a, 320b, 420a, 420b, 520a, 520b ... timing cells
22 ... Address storage memory 28 ... Control circuit
52,152,252,352,452,500 ... two-dimensional code
54A, 54B, 54C, 154A, 154B, 154C, 254A, 254B, 254C, 254D, 354A, 354B, 354C, 454A, 454B, 454C, 510a, 510b, 510c ... positioning symbols
56, 156, 256, 356, 456, 530 ... data area
60 ... auxiliary symbol
70 ... Format code 80 ... Version information

Claims (11)

A positioning symbol for specifying the position of the two-dimensional code, which is arranged at a predetermined position in the two-dimensional code expressing information by a cell distribution pattern , and a timing cell which is a reference pattern serving as an index of each data cell position , A first information expressed using a cell having the same cell size as a cell constituting the positioning symbol, and a second information expressed using a cell having a smaller cell size than the cell constituting the positioning symbol. Are two-dimensional code reading methods arranged at predetermined positions in the two-dimensional code, respectively.
Obtaining an image of the two-dimensional code and performing a two-dimensional code positioning process for detecting a position of the positioning symbol in the image;
Next, a cell that detects the position of the data cell of at least one of the first information and the second information in the two-dimensional code based on the position of the positioning symbol and the cell size of each information Perform positioning processing,
Next, based on the data cell in which the position is detected, a decoding process for reading at least one of the first information and the second information is performed. Reading method. The method for reading a two-dimensional code according to claim 1,
The decoding process selects and reads code information of only one of the first information and the second information,
A method for reading a two-dimensional code characterized by the above. The method for reading a two-dimensional code according to claim 1,
In the second information, a plurality of types of information are expressed using cells having different cell sizes,
In the cell positioning process, the position of at least one of the data cells of the plurality of cell sizes constituting the first information or the second information in the two-dimensional code is set in the positioning symbol. Detect based on location and cell size of each information,
The decoding process reads at least one code information of each information of a plurality of cell sizes constituting the first information and the second information based on the data cell in which the position is detected. ,
A method for reading a two-dimensional code characterized by the above. In the reading method of the two-dimensional code in any one of Claims 1-3,
The first information in the two-dimensional code to be read is expressed by a code using a code type corresponding to the positioning symbol, and the second information has a code type different from the first information. It is expressed in the code used,
The decoding process reads the code information using a decoding algorithm corresponding to the code type used for the information to be decoded,
A method for reading a two-dimensional code characterized by the above. The method for reading a two-dimensional code according to claim 4,
The second information in the two-dimensional code to be read is composed of a plurality of types of information using cells having different cell sizes, and each piece of information constituting the second information is different from the first information. It is expressed by a code using a code type different from the code using a code type, and is expressed by a code using a code type different from each other,
The decoding process reads the code information using a decoding algorithm corresponding to the code type used for the information to be decoded,
A method for reading a two-dimensional code characterized by the above. In the reading method of the two-dimensional code in any one of Claims 1-5,
The two-dimensional code is further provided with a format code that is arranged at a predetermined position with respect to the positioning symbol and that can specify an existing area and a cell size for each of the information in the two-dimensional code,
After performing the two-dimensional code positioning process, the format code is detected based on the detected position of the positioning symbol, and the format acquisition process for acquiring the format of the two-dimensional code represented by the format code is performed.
The cell positioning process detects the position of the data cell based on the acquired format of the two-dimensional code;
A method for reading a two-dimensional code characterized by the above. The two-dimensional code reading method according to claim 4 or 5,
The two-dimensional code is further provided with a format code that is arranged at a predetermined position with respect to the positioning symbol and that can specify an existing area, a cell size, and a use code type for each of the pieces of information in the two-dimensional code. And
After performing the two-dimensional code positioning process, the format code is detected based on the detected position of the positioning symbol, and the format acquisition process for acquiring the format of the two-dimensional code represented by the format code is performed.
The cell positioning process detects the position of the data cell based on the acquired two-dimensional code format,
The decoding process specifies a decoding algorithm corresponding to a code type based on the acquired two-dimensional code format, and reads code information using the specified decoding algorithm;
A method for reading a two-dimensional code characterized by the above. In the reading method of the two-dimensional code in any one of Claims 1-7,
The two-dimensional code includes an auxiliary symbol that is arranged at a position different from the positioning symbol in the two-dimensional code and is detected based on the position of the positioning symbol and its own pattern. Yes,
After performing the two-dimensional code positioning process, an auxiliary symbol positioning process for detecting the position of the auxiliary symbol in the image is performed based on the detected position of the positioning symbol and the pattern of the auxiliary symbol. ,
The cell positioning process detects the position of the data cell based on the auxiliary symbol;
A method for reading a two-dimensional code characterized by the above. A positioning symbol for specifying the position of the two-dimensional code, which is arranged at a predetermined position in the two-dimensional code expressing information by a cell distribution pattern , and a timing cell which is a reference pattern serving as an index of each data cell position , And the first information expressed by the two-dimensional code reading method using the code type corresponding to the positioning symbol and the second information expressed by the bar code are respectively in the two-dimensional code. A method for reading a two-dimensional code arranged at a predetermined position of
Obtaining an image of the two-dimensional code and performing a two-dimensional code positioning process for detecting a position of the positioning symbol in the image;
Next, the position of at least one of the data cell for expressing the first information or the bar for expressing the second information in the two-dimensional code is based on the position of the positioning symbol. Perform positioning processing for the cells to be detected,
Next, decoding processing of at least one of reading of the code information of the first information based on the data cell where the position is detected or reading of the code information of the second information based on the bar where the position is detected A method for reading a two-dimensional code, comprising: The method for reading a two-dimensional code according to claim 9,
The two-dimensional code is further provided with a format code that is arranged at a predetermined position with respect to the positioning symbol and that can specify a presence area and a use code type for each of the pieces of information in the two-dimensional code,
After performing the two-dimensional code positioning process, the format code is detected based on the detected position of the positioning symbol, and the format acquisition process for acquiring the format of the two-dimensional code represented by the format code is performed.
The positioning process for the cells and the like is based on the acquired two-dimensional code format, and at least one position of a data cell for expressing the first information or a bar for expressing the second information Detect
The decoding process specifies a decoding algorithm corresponding to a code type based on the acquired two-dimensional code format, and reads code information using the specified decoding algorithm;
A method for reading a two-dimensional code characterized by the above. 11. A recording medium in which the two-dimensional code reading method according to claim 1 is recorded as a program executed by a computer system.

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