JP7167553B2 - Two-dimensional code - Google Patents

Description

The present invention relates to a two-dimensional code having a plurality of cells arranged in a matrix.

Conventionally, various types of two-dimensional codes having a plurality of cells arranged in a matrix have been provided. A reading device (two-dimensional code reader) that reads this type of two-dimensional code acquires image data containing the two-dimensional code, and then detects the area of the two-dimensional code (code area) from the image data. analysis processing is performed, the coordinates of each cell are determined based on the image content from the detected code area, the color of the cell is determined from the image information of each coordinate position, and decoding processing is performed. target. For example, the data matrix disclosed in Patent Document 1 is known as a technology related to such two-dimensional codes.

JP-A-07-152885

When reading a captured two-dimensional code, it is necessary to accurately detect the code area of the two-dimensional code and the coordinates of each cell in the captured image. However, like the data matrix disclosed in Patent Document 1, the L-shaped line is arranged so that the edge where the dark cells are arranged in a row in an L-shape and the light-colored cells and the dark-colored cells are alternately arranged. The following problem may occur in the configuration that detects a rectangular code area by using the edges arranged in parallel. For example, when detecting a code region from a captured image, even if the data matrix is not captured, if a solid line portion corresponding to a linear region in which dark cells are arranged in a line is captured, the data matrix will be captured. Assuming that there is a possibility that the code region is

That is, when a two-dimensional code that uses a linear region in which dark cells are arranged in a line as a pattern for detecting the code region is read, only the solid line portion unrelated to the two-dimensional code is captured. There is a problem that the detection processing for detecting the code area is wasted. Further, even if the two-dimensional code as described above is captured, if the captured image includes an irrelevant solid line portion, the detection process for detecting the code area is performed based on the solid line portion. Sometimes. In particular, even if the solid line portion is L-shaped, there is a possibility that it will be included in the captured image because it is composed of the edge portion of the display surface where the two-dimensional code is displayed, the frame line of the table provided on the display surface, and the like. Because of the high cost, the above problems are likely to occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object thereof is to provide a two-dimensional code that can suppress unnecessary code detection processing for code region detection.

In order to achieve the above object, the invention described in claim 1 of the scope of claims includes:
A two-dimensional code (30, 30a to 30e) in which a plurality of types of cells are arranged in a matrix in a rectangular code area (31),
Among the outer edges (34) of the code region, a first edge (34a) formed by arranging the plurality of types of cells in a row has a specific pattern (a) formed by arranging two or more different cells at least in an intermediate portion. 40, 40a) are repeated, and the second edge (34b) formed by arranging the plurality of types of cells in a row so as to face the first edge has the specific pattern at least at an intermediate portion. consists of repeated
A first position detection pattern used for detecting the code region is arranged at one of the corners of the code region,
the first edge is configured such that the specific pattern is repeated until the first locating pattern is reached;
At the corner of the code area diagonal to the first position detection pattern, a second position detection pattern used for detecting the code area is arranged in a different arrangement from the first position detection pattern. placed and
The second edge is characterized in that the specific pattern is repeated until the second position detection pattern is reached .
It should be noted that the symbols in parentheses above indicate the corresponding relationship with specific means described in the embodiments to be described later.

In the invention of claim 1, among the outer edges of the rectangular code region, the first edge formed by arranging a plurality of types of cells in a row is specified by arranging two or more different cells at least in the intermediate portion. The pattern is repeated, and the second edge, in which a plurality of types of cells are arranged in a row so as to face the first edge, is configured by repeating the specific pattern at least in the intermediate portion.

In this way, since at least the intermediate portion of the first edge and the second edge that face each other is formed by repeating the specific pattern, two parallel parts in which the specific pattern is repeated are detected from the captured image. If possible, the coding region can be detected with the two parallel portions as the opposing outer edges. In particular, a periodic pattern such as a repetition of the above specific pattern is difficult to be composed of frame lines, characters, etc. displayed on the display surface together with the two-dimensional code, and unlike the solid line portion, it is unlikely to be included in the captured image. Therefore, when the code region is not imaged, unnecessary code detection processing can be suppressed for detection of the code region.

In the invention of claim 1 , the first position detection pattern used for detecting the code region is arranged at one of the corners of the code region, and the first edge reaches the first position detection pattern. A specific pattern is configured to be repeated until Therefore, the first edge can be easily detected using the detected first position detection pattern as a reference.

According to the first aspect of the invention, the second position detection pattern used for detecting the code region is provided at the corner of the code region diagonal to the first position detection pattern. Arranged in a different arrangement, the second edge is configured such that the particular pattern is repeated until the second locating pattern is reached. Therefore, the second edge can be easily detected using the detected second position detection pattern as a reference.

In particular, since the arrangement is different between the first position detection pattern and the second position detection pattern, the positional relationship between the first position detection pattern, the second position detection pattern, the first edge, and the second edge , it is possible to easily determine whether or not the image is captured with the code area reversed. As a result, only one of the processes of decoding the code area detected from the captured image in a reversed state and decoding in a non-reversed state can be performed without performing the two processes. Therefore, it is possible to shorten the processing time for the reading process of reading the two-dimensional code.

In the second aspect of the invention, the first edge is configured such that at least one of the starting edge and the trailing edge has a pattern for the edge different from the specific pattern. The end of one edge, ie the outer edge of the coding region orthogonal to the first edge, can be easily detected.

According to the third aspect of the invention, the second edge is configured such that at least one of the starting end and the terminating end has a pattern for the end that is different from the specific pattern. The end of the two edges, ie the outer edge of the coding region orthogonal to the second edge, can be easily detected.

In the invention according to claim 4 , in the code region, the division pattern in which the cell arrangement is the same from the first edge to the second edge in the opposing direction perpendicular to the first edge and the second edge. 1 or more are arranged. This makes it easier to accurately determine the position (cell coordinates) of each cell in the code region in the direction along the first edge and the second edge (the direction orthogonal to the facing direction), based on the division pattern, The decoding success rate can be increased.

In the invention of claim 5 , among the outer edges of the code region, the third edge and the fourth edge that face each other so as to be orthogonal to the first edge and the second edge are at least the cells constituting the intermediate portion. The type is configured to be the same type as the cells of the segmentation pattern at opposing positions in the direction along the first edge and the second edge. As a result, it becomes easier to accurately obtain the cell coordinates of each cell with respect to the direction along the first edge and the second edge, based not only on the division pattern but also on the intermediate portions of the third edge and the fourth edge, The decoding success rate can be further increased.

In the sixth aspect of the invention, since the size of the code region is determined by the position where the division pattern contacts the first edge, the size of the code region can be immediately specified by obtaining the position where the division pattern contacts the first edge. can be done. That is, when detecting the code region, the code region can be detected only by obtaining the number of cells arranged in one direction from the cell at a predetermined position such as the cell forming the end of the first edge to the cell in contact with the division pattern. Since the size is specified, the size of the code region can be specified at an early stage without obtaining a two-dimensional array of cells. Since the size of the code area can be specified in this way, even if there is a part that looks like an aggregate of cells near the code area, processing for detecting the code area is not performed on that part, so it is unnecessary. Therefore, it is possible to shorten the processing time for the reading processing.

In the invention of claim 7 , the portion where the specific pattern is repeated on the first edge and the portion where the specific pattern is repeated on the second edge are opposed in the facing direction orthogonal to the first edge and the second edge. are of the same type. As a result, it becomes easier to accurately obtain the cell coordinates of each cell in the facing direction with reference to each specific pattern, and the decoding success rate can be increased.

In particular , the first edge and the second edge are configured such that one or more second specific patterns differing in arrangement from the specific pattern appear during repetition of the specific pattern, and the second edge of the first edge Cells at positions facing each other in the facing direction between the specific pattern and the second specific pattern of the second edge are of the same type. This makes it easier to accurately obtain the cell coordinates of each cell with respect to the facing direction based on not only each specific pattern but also the second specific pattern, thereby further increasing the decoding success rate.

In the eighth aspect of the invention, each of the first edge and the second edge is configured such that one or more second specific patterns appear, and from the second specific pattern of the first edge in the facing direction Dividing patterns each having the same arrangement of cells are arranged over the second specific pattern on the opposing second edge. Thereby, the cell coordinates of each cell in the facing direction are obtained with each specific pattern and the second specific pattern as a reference, and the cell coordinates of each cell in directions along the first edge and the second edge are obtained by dividing the dividing pattern. can be obtained as a criterion, and the decoding success rate can be further increased.

In the ninth aspect of the invention, the second specific pattern is configured by arranging three cells of the same type, and the division pattern is such that the end cells in contact with the central cell of the second specific pattern are the second specific pattern. The second specific pattern is composed of cells of a different type, and the cells surrounding this end cell are composed of cells of the same type as the cells that constitute the second specific pattern. As a result, the end cells of the divided pattern are not only surrounded by different types of cells, but also the cells surrounding the end of the divided pattern are all of the same type. can be easily detected, and as a result, the division pattern and the second specific pattern can be easily detected.

In the invention of claim 10 , among the outer edges of the code region, the third edge and the fourth edge that face each other so as to be orthogonal to the first edge and the second edge are at least the cells constituting the intermediate portion. The type is configured to be the same type as the cells of the segmentation pattern at opposing positions in the direction along the first edge and the second edge. As a result, it becomes easier to accurately obtain the cell coordinates of each cell with respect to the direction along the first edge and the second edge, based not only on the division pattern but also on the intermediate portions of the third edge and the fourth edge, The decoding success rate can be further increased.

In the eleventh aspect of the invention, since the size of the code region is determined by the position where the division pattern contacts the first edge, the size of the code region can be immediately specified by obtaining the position where the division pattern contacts the first edge. can be done. That is, when detecting the code region, the code region can be detected only by obtaining the number of cells arranged in one direction from the cell at a predetermined position such as the cell forming the end of the first edge to the cell in contact with the division pattern. Since the size is specified, the size of the code region can be specified at an early stage without obtaining a two-dimensional array of cells. Since the size of the code area can be specified in this way, even if there is a part that looks like an aggregate of cells near the code area, processing for detecting the code area is not performed on that part, so it is unnecessary. Therefore, it is possible to shorten the processing time for the reading processing.

In the twelfth aspect of the invention, the specific pattern consists of a set of bright color cells and dark color cells. In this way, even if the first edge and the second edge are configured to have a periodic pattern in which bright cells and dark cells are alternately repeated, they can be displayed on the display surface together with the two-dimensional code. Unlike the solid line portion, it is less likely to be included in the captured image. Therefore, when the code region is not captured, unnecessary code detection processing is suppressed regarding detection of the code region. can do.

In the thirteenth aspect of the invention, the first edge and the second edge are configured to be the long sides of the rectangular code area. As a result, compared to the case where the first edge and the second edge are the short sides of the code region, the frequency of repeated appearance of the specific pattern increases. edges can be easily detected.

FIG. 3 is an explanatory diagram showing a two-dimensional code according to the first embodiment; FIG. 1 is a block diagram schematically illustrating an electrical configuration of an information code reader that reads a two-dimensional code according to the first embodiment; FIG. It is a flowchart which illustrates the flow of the reading process performed in the control part of an information code reader. FIG. 2 is an explanatory diagram illustrating a state in which the two-dimensional code of FIG. 1 is reversed; FIG. 11 is an explanatory diagram showing a two-dimensional code according to the first modified example of the first embodiment; FIG. 11 is an explanatory diagram showing a two-dimensional code according to a second modified example of the first embodiment; FIG. 11 is an explanatory diagram showing a two-dimensional code according to the second embodiment; FIG. 11 is an explanatory diagram showing a two-dimensional code according to the first modified example of the second embodiment; FIG. 11 is an explanatory diagram showing a two-dimensional code according to a second modified example of the second embodiment; FIG. 11 is an explanatory diagram showing a two-dimensional code according to the third embodiment; FIG. 11(A) is an explanatory diagram for explaining a state in which the code size and the number of size-specifying cells correspond one-to-one. is an explanatory diagram for explaining a state in which are in one-to-many correspondence.

[First embodiment]
A first embodiment embodying a two-dimensional code of the present invention will be described below with reference to the drawings.
First, the structure of the two-dimensional code according to this embodiment will be described with reference to FIG.
The two-dimensional code 30 according to the present embodiment, as shown in FIG. ) are arranged in a matrix. The code area 31 is divided into a fixed pattern area in which a pattern of a predetermined shape is arranged and a data recording area 32 in which data is recorded using a plurality of types of cells. As a result, the code area 31 occupying the captured image can be detected using the fixed pattern area, and the data recorded in the two-dimensional code 30 can be read using the data recording area 32 of the detected code area 31 . The data recording area 32 can include an error correction code recording area for recording an error correction code. In addition, in FIG. 1 and the like, the data recording area 32 is hatched.

The fixed pattern areas are a first position detection pattern 33a arranged at one corner of the code area 31 and a corner of the code area 31 diagonal to the first position detection pattern 33a. and an outer edge 34 of the code area 31 excluding the first position detection pattern 33a and the second position detection pattern 33b.

In this embodiment, as shown in FIG. 1, the two-dimensional code 30 is configured by arranging two types of cells, bright cells and dark cells, in a matrix. The first position detection pattern 33a includes nine dark cells arranged in a square shape in the center, a bright cell group surrounding these nine dark cells in a line, and this bright cell group in a line. and an L-shaped bright cell group separating the dark cell group from the data recording area 32 . For this reason, the first position detection pattern 33a has a continuous ratio of 1:1:3:1 in the order of dark, light, dark, light, and dark, similar to the position detection pattern of the QR code (registered trademark). It can be detected based on the area of 1.

The second position detection pattern 33b is composed of one central dark cell, a bright cell group surrounding the dark cell in a row, and a dark cell group surrounding the bright cell group in a row. be. Therefore, the second position detection pattern 33b can be detected based on an area in which the continuous ratio is 1:1:1:1:1 in the order of dark, bright, dark, bright, and dark.

The outer edge 34 of the code area 31 is formed by arranging each cell in a row, and includes a first edge 34a forming a long side on the first position detection pattern 33a side and a second position detection pattern 33b. a second edge 34b forming the long side of the first position detection pattern 33a; a third edge 34c forming the short side of the first position detection pattern 33a; 4 edges 34d.

The first edge 34a has one end connected to the first position detection pattern 33a, and the other end consisting of three dark cells as an end pattern 35a. is composed of alternately arranged light cells and dark cells. That is, the first edge 34a is formed by repeating the specific pattern 40, which is formed by arranging a set of bright-colored cells and dark-colored cells, at least at the intermediate portion until it reaches the first position detection pattern 33a.

The second edge 34b has one end composed of three dark cells as an end pattern 35b, and the other end connected to the second position detection pattern 33b, excluding the end pattern 35b. is composed of alternately arranged light cells and dark cells. That is, the second edge 34b is configured by repeating the specific pattern 40 configured in the same manner as the first edge 34a at least at the intermediate portion until it reaches the second position detection pattern 33b.

In particular, the second edge 34b has a portion where the specific pattern 40 is repeated on the first edge 34a (see L1 in FIG. 1) and a portion where the specific pattern 40 is repeated on the second edge 34b (see L2 in FIG. 1). , so that the cells facing each other in the facing direction (the Y direction in FIG. 1) orthogonal to the first edge 34a and the second edge 34b are of the same type. Therefore, for example, the cell of the first edge 34a and the cell of the second edge 34b through which the one-dot chain line S1 extending in the opposite direction in FIG. 1 passes become the same dark color cells.

One end of the third edge 34c is connected to the first position detection pattern 33a, and the other end is a pattern 35c for the edge, which is the same dark color cell as the pattern 35b for the edge of the second edge 34b. It is configured to consist of An intermediate portion between one end and the other end is configured such that the specific pattern 40 is repeated. The edge pattern 35c is connected to the edge pattern 35b of the second edge 34b in an L-shape to form one edge between the edge pattern 35c and the edge pattern 35b. The corner pattern 33c is configured together with the light-colored cells.

One end of the fourth edge 34d is a pattern 35d for the edge, which is the same dark color cell as the pattern 35a for the edge of the first edge 34a, and the other end is the second position detection pattern 33b. is configured to be connected to An intermediate portion between one end and the other end is configured such that the specific pattern 40 is repeated. The edge pattern 35d is connected to the edge pattern 35a of the first edge 34a in an L-shape to form one edge between the edge pattern 35d and the edge pattern 35a. The corner pattern 33d is configured together with the bright color cells.

In the two-dimensional code 30 configured as described above, the first edge 34a and the second edge 34b facing each other are configured by repeating the specific pattern 40 at least in the intermediate portion. If it is possible to detect two parallel portions in which 40 is repeated, it is possible to detect the code region 31 having the two parallel portions as opposed outer edges. In particular, a periodic pattern in which the specific pattern 40 is repeated is less likely to be included in the same captured image unless such a pattern is intentionally arranged.

Next, the information code reader 1 functioning as a two-dimensional code reader capable of optically reading the two-dimensional code 30 according to this embodiment will be described with reference to FIG.
The information code reader 1 according to the present embodiment is a portable reader that optically reads a two-dimensional code 30, bar code, or the like. As shown in FIG. 2, the information code reader 1 has a circuit portion housed inside a case (not shown). etc., and a microcomputer (hereinafter referred to as "microcomputer") system such as a memory 16 and a control unit 20 . The information code reader 1 may be configured as a stationary reader.

The optical system is divided into a projecting optical system and a receiving optical system. The illumination light source 11 constituting the projection optical system functions as an illumination light source capable of emitting the illumination light Lf, and is composed of, for example, a red LED and a lens provided on the emission side of the LED. Note that FIG. 2 conceptually shows an example of irradiating the illumination light Lf toward the reading object R to which the two-dimensional code 30 is attached.

The light-receiving optical system includes a light-receiving sensor 13, an imaging lens 12, a reflecting mirror (not shown), and the like. The light-receiving sensor 13 is configured as an area sensor in which light-receiving elements, which are solid-state imaging elements such as C-MOS and CCD, are arranged two-dimensionally, and each cell (pattern) of the received information code is reflected. It is configured to output an electrical signal corresponding to the intensity of the light Lr. The light-receiving sensor 13 is mounted on a printed wiring board (not shown) so as to be able to receive incident light that enters through the imaging lens 12 .

The image-forming lens 12 functions as an image-forming optical system capable of condensing incident light incident from the outside through a reading port (not shown) and forming an image on the light-receiving surface 13a of the light-receiving sensor 13. . In this embodiment, after the illumination light Lf or the like emitted from the illumination light source 11 is reflected by the information code or the like, the reflected light Lr is condensed by the imaging lens 12, and the code image is formed on the light receiving surface 13a of the light receiving sensor 13. is imaged.

The microcomputer system includes an amplifier circuit 14, an A/D conversion circuit 15, a memory 16, an address generation circuit 17, a synchronization signal generation circuit 18, a control section 20, an operation section 21, a liquid crystal display 22, a buzzer 23, a vibrator 24, and a light emitting section. 25, a communication interface 26, and the like. As the name suggests, this microcomputer system is mainly composed of a control unit 20 and a memory 16 that can function as a microcomputer (information processing device), and includes the two-dimensional code 30 imaged by the optical system described above. The image signal of the information code can be signal-processed by hardware and software. The control unit 20 also controls the overall system of the information code reader 1 .

An image signal (analog signal) output from the light-receiving sensor 13 of the optical system is input to the amplifier circuit 14 to be amplified by a predetermined gain, and then input to the A/D conversion circuit 15 to convert the analog signal into converted to a digital signal. When the digitized image signal, that is, image data (image information) is input to the memory 16, it is stored in the image data storage area. The synchronizing signal generating circuit 18 is configured to be able to generate a synchronizing signal for the light receiving sensor 13 and the address generating circuit 17. The address generating circuit 17 operates based on the synchronizing signal supplied from the synchronizing signal generating circuit 18. , the storage address of the image data stored in the memory 16 can be generated.

The memory 16 is a semiconductor memory device such as a RAM (DRAM, SRAM, etc.) or a ROM (EPROM, EEPROM, etc.). In the RAM of the memory 16, in addition to the above-described image data storage area, a work area and a reading condition table used by the control unit 20 during each processing such as arithmetic operation and logical operation can be secured. . Further, the ROM stores in advance a system program and the like capable of controlling each hardware such as the illumination light source 11 and the light receiving sensor 13 . The memory 16 also stores specific patterns 40 forming the first edge 34a and the second edge 34b of the two-dimensional code 30 to be read, edge patterns, position detection patterns 33a and 33b, and corner patterns 33c. , 33d and the like (hereinafter also referred to as specific pattern information) and a program for executing the reading process of optically reading the two-dimensional code 30 using the specific pattern information. ing.

The control unit 20 is a microcomputer capable of controlling the entire information code reader 1, and includes a CPU, a system bus, an input/output interface, and the like. The control unit 20 is configured to be connectable to various input/output devices (peripheral devices) via a built-in input/output interface. , a vibrator 24, a light emitting unit 25, a communication interface 26, and the like are connected.

The operation unit 21 is composed of a plurality of keys, and is configured to give an operation signal to the control unit 20 according to the key operation of the user. is configured to perform an operation corresponding to the operation signal. The liquid crystal display 22 is composed of a known liquid crystal display panel, and the display contents are controlled by the control section 20 . The buzzer 23 is a known buzzer and is configured to generate a predetermined sound in response to an operation signal from the control section 20 . The vibrator 24 is composed of a known vibrator mounted on a portable device, and is configured to generate vibration according to a drive signal from the control section 20 . The light emitting unit 25 is, for example, an LED, and is configured to light up according to a signal from the control unit 20 . The communication interface 26 is configured as an interface for performing data communication with an external device (for example, a host device), and cooperates with the control unit 20 to perform communication processing.

Next, reading processing executed by the control unit 20 of the information code reading device 1 when reading the two-dimensional code 30 will be described with reference to the flowchart of FIG.
When a predetermined operation is performed on the operation unit 21 while the reading opening of the information code reading device 1 is directed toward the two-dimensional code 30, reading processing by the control unit 20 is started. First, an imaging process shown in step S101 is performed, and image data of a captured image including the two-dimensional code 30 is generated based on a signal output from the light receiving sensor 13 that has received the reflected light Lr from the two-dimensional code 30. be.

Next, an outer edge detection process shown in step S103 is performed. In this process, based on specific pattern information or the like stored in advance in the memory 16, two parallel portions where the specific pattern 40 is repeated from the captured image captured as described above, that is, the first edge 34a and the Processing is performed to detect the second edge 34b. In this process, the first edge 34a and the second edge 34b may be directly detected from the captured image using the specific pattern 40, the edge patterns 35a and 35b, or the like, or may be detected from the captured image. The first edge 34a and the second edge 34b may be detected based on the positions of the position detection patterns 33a and 33b and the corner patterns 33c and 33d.

Then, since the two-dimensional code 30 is captured, when the first edge 34a and the second edge 34b are detected from the captured image (Yes in S105), the code area detection process shown in step S107 is performed. is done. In this process, the code region 31 is detected based on the first edge 34a and the second edge 34b detected as described above, the first position detection pattern 33a and the second position detection pattern 33b, and the like. .

Then, the decoding process shown in step S109 is performed to decode (decode) the predetermined data recorded in the data recording area 32 based on the array of cells in the code area 31 detected as described above. is done. If the decoding process succeeds (Yes in S111), the process for outputting the predetermined data obtained by the decoding process is performed (S113), and the reading process ends. On the other hand, if the decoding process fails (No in S111), it is determined that the two-dimensional code 30 has not been imaged in a decodable manner, and the processes from step S101 are performed.

Further, when the first edge 34a and the second edge 34b are not detected from the imaged image (No in S105), it is determined that the two-dimensional code 30 is not imaged, and the code area 31 is detected. The processing from step S101 is performed without performing the detection processing (S107).

As described above, in the two-dimensional code 30 according to the present embodiment, among the outer edges 34 of the rectangular code region 31, the first edge 34a formed by arranging a plurality of types of cells in a line is at least the intermediate portion. In the above, the specific pattern 40 formed by arranging two or more different cells is repeated, and the second edge 34b is formed by arranging a plurality of types of cells in a row so as to face the first edge 34a, The specific pattern 40 is repeated at least in the intermediate portion.

In this manner, the first edge 34a and the second edge 34b facing each other are formed by repeating the same specific pattern 40 at least in the intermediate portion, so that two parallel edges in which the specific pattern 40 is repeated from the captured image are formed. If the portion can be detected, the code region 31 can be detected with the two parallel portions being the first edge 34a and the second edge 34b of the outer edge 34 facing each other. In particular, a periodic pattern such as the repeating specific pattern 40 is difficult to be composed of frame lines, characters, etc. displayed on the display surface together with the two-dimensional code 30, and may be included in the captured image unlike the solid line portion. is low, unnecessary code detection processing for detecting the code region 31 can be suppressed when the code region 31 is not imaged. As a result, the processing time for the reading process in the information code reader 1 can be shortened.

A first position detection pattern 33a used for detecting the code region 31 is arranged at one of the corners of the code region 31, and the first edge 34a reaches the first position detection pattern 33a. The specific pattern 40 is configured to be repeated until the specified pattern 40 is reached. Therefore, when detecting the first edge 34a based on the detected first position detection pattern 33a, the detection process can be easily performed.

At the corner of the code area 31 diagonal to the first position detection pattern 33a, a second position detection pattern 33b used for detection of the code area 31 is positioned as the first position detection pattern 33a. Arranged in a different arrangement, the second edge 34b is configured such that the particular pattern 40 is repeated until the second locating pattern 33b is reached. Therefore, when detecting the second edge 34b with the detected second position detection pattern 33b as a reference, the detection process can be easily performed. Further, when one of the first position detection pattern 33a and the second position detection pattern 33b is detected, by searching for the other with reference to the location, two corners located diagonally of the code region 31 can be detected. can be detected, and the outer shape of the code area 31 can be easily detected.

In particular, since the arrangement is different between the first position detection pattern 33a and the second position detection pattern 33b, the first position detection pattern 33a and the second position detection pattern 33b and the first edge 34a and the second edge From the positional relationship with 34b, it can be easily determined whether or not the image of the code area 31 is reversed. As a result, two processes are performed on the code area 31 detected from the captured image: decoding in a reversed state (see FIG. 4) and decoding in a non-reversed state (see FIG. 1). Therefore, it is possible to shorten the processing time for the reading process of reading the two-dimensional code 30 .

Furthermore, the first edge 34a is configured such that the end opposite to the first position detection pattern 33a is the end pattern 35a different from the specific pattern 40. Using the pattern 35a as a reference, the end of the first edge 34a, that is, the fourth edge 34d, which is the outer edge of the code region 31 perpendicular to the first edge 34a, can be easily detected.

In addition, the second edge 34b is configured such that the end opposite to the second position detection pattern 33b is the end pattern 35b different from the specific pattern 40. Using the pattern 35b as a reference, the end of the second edge 34b, that is, the third edge 34c, which is the outer edge of the code region 31 perpendicular to the second edge 34b, can be easily detected.

In particular, the portion where the specific pattern 40 is repeated on the first edge 34a (see L1 in FIG. 1) and the portion where the specific pattern 40 is repeated on the second edge 34b (see L2 in FIG. 1) Cells at positions facing each other in the facing direction (Y direction in FIG. 1) orthogonal to 34a and second edge 34b are of the same type (see S1 in FIG. 1). As a result, it becomes easier to accurately obtain the cell coordinates of each cell in the facing direction with reference to each specific pattern 40, and the decoding success rate can be increased.

Since the specific pattern 40 consists of a set of bright cells and dark cells, the first pattern 40 has a periodic pattern in which bright cells and dark cells are alternately repeated. Even if the edge 34a and the second edge 34b are formed, they are unlikely to be formed from frame lines or characters displayed on the display surface together with the two-dimensional code 30. When the code region 31 is not imaged, unnecessary code detection processing can be suppressed for detection of the code region 31 .

It should be noted that the specific pattern 40 is not limited to being composed of a set of bright and dark cells, and may be composed of a combination of other cells so that the outer edge has periodicity by being continuous. For example, as a first modified example of the present embodiment, a specific pattern 40a in a two-dimensional code 30a illustrated in FIG. 5 may be composed of one light-colored cell and three dark-colored cells.

Further, since the first edge 34a and the second edge 34b are configured to be the long sides of the rectangular code region 31, the first edge 34a and the second edge 34b are the short sides of the code region 31. Since the frequency of repeated appearance of the specific pattern 40 is increased compared to the case where it is configured to be sides, the first edge 34a and the second edge 34b can be easily detected.

Depending on the environment in which the two-dimensional code 30 is used, the code area 31 may be configured in a square shape, or the first edge 34a and the second edge 34a configured by repeating the specific pattern 40 described above. The edge 34b may be configured to be the short side.

Moreover, the fixed pattern area is not limited to being configured to include both the two first position detection patterns 33a and the second position detection patterns 33b, and may be configured to include either one. . Also, the two first position detection patterns 33a and second position detection patterns 33b may be eliminated. In this case, as a second modification of the present embodiment, the first edge 34a has a specific pattern 40 at the beginning and the end like the end patterns 35a and 36a of the two-dimensional code 30b illustrated in FIG. By configuring so as to have a pattern for the ends (for example, a pattern consisting of three dark cells) different from that of the first edge 34a, with the patterns 35a and 36a for the ends as a reference, That is, it is possible to easily detect the third edge 34c and the fourth edge 34d, which are the outer edges of the code region 31 orthogonal to the first edge 34a. Similarly, the second edge 34b may be configured such that the start and end of the second edge 34b are different from the specific pattern 40, such as the end patterns 35b and 36b illustrated in FIG. Based on the patterns 35b and 36b for the ends, both ends of the second edge 34b, that is, the third edge 34c and the fourth edge 34c which are the outer edges of the code region 31 perpendicular to the second edge 34b. Edge 34d can be easily detected.

Also, as illustrated in FIG. 6, a corner formed by a pattern 36a for the end of the first edge 34a, a pattern 36c for the end of the third edge 34c, and a bright cell between the two patterns. By using the pattern, the first edge 34a and the third edge 34c can be detected. Further, by using a corner pattern composed of the pattern 36b for the end of the second edge 34b, the pattern 36d for the end of the fourth edge 34d, and the bright color cells between the two patterns, the The second edge 34b and the fourth edge 34d can be detected.

[Second embodiment]
Next, a two-dimensional code according to the second embodiment will be described with reference to FIG.
In the second embodiment, as a part of the fixed pattern area, a division pattern for dividing the data recording area 32 in the facing direction is newly arranged in the code area 31, which is the main difference from the first embodiment. different. Therefore, the same reference numerals are assigned to substantially the same components as those of the two-dimensional code of the first embodiment, and the description thereof will be omitted.

As shown in FIG. 7, the first edge 34a and the second edge 34b of the two-dimensional code 30c according to the present embodiment have a second specific pattern 41 different in arrangement from the specific pattern 40, while the specific pattern 40 is being repeated. It is configured so that two appear in . The second specific pattern 41 is composed of, for example, three dark cells so as to disturb the periodicity using the specific pattern 40, and the second specific pattern 41 on the first edge 34a and the second specific pattern 41 on the second edge 34b. Cells at positions opposed to the second specific pattern 41 in the opposing direction are of the same type.

Then, in the facing direction, from the dark cell at the center of the second specific pattern 41 on the first edge 34a to the dark cell at the center of the second specific pattern 41 on the opposing second edge 34b. Division patterns 37 having the same arrangement are arranged. Similar to the first edge 34a and the second edge 34b, the divided pattern 37 has bright cells and dark cells alternately arranged in a line, and the end portion contacting the central dark cell of the second specific pattern 41 The cells 37a are configured to be bright color cells of a different type from the cells forming the second specific pattern 41. FIG.

As a result, the dividing pattern 37 can be made to function as an alignment pattern and used to correct distortion of cell coordinates. In particular, in the present embodiment, the cells adjacent to the cells 37a at the ends of the divided pattern 37 are also included in the fixed pattern region, and the cells surrounding the cells 37a at the ends are the cells forming the second specific pattern 41. It consists of cells of the same type (dark cells).

The third edge 34c and the fourth edge 34d face each other in the direction along the first edge 34a and the second edge 34b (the X direction in FIG. 7) at least in the type of cells that constitute the intermediate portion. It is constructed so as to be of the same type as the cell of the division pattern 37 at the position. For this reason, for example, with respect to the types of cells that the one-dot chain line S2 extending in the X direction in FIG. becomes a cell.

As described above, in the two-dimensional code 30c according to the present embodiment, the first edge 34a and the second edge 34b have the second specific pattern 41 different in arrangement from the specific pattern 40, and the specific pattern 40 is repeated. The second specific pattern 41 of the first edge 34a and the second specific pattern 41 of the second edge 34b are of the same type at positions facing each other in the opposing direction. be. As a result, it becomes easier to accurately obtain the cell coordinates of each cell with respect to the facing direction, using not only each specific pattern 40 but also the second specific pattern 41 as a reference, and the decoding success rate can be further increased.

The first edge 34a and the second edge 34b are each configured so that two second specific patterns 41 appear, and the second specific pattern 41 from the first edge 34a in the facing direction Dividing patterns 37 each having the same cell arrangement are arranged over the second specific pattern 41 of the opposing second edge 34b. As a result, the cell coordinates of each cell in the facing direction (the Y direction in FIG. 7) are determined with reference to each specific pattern 40 and the second specific pattern 41, and along the first edge 34a and the second edge 34b The cell coordinates of each cell with respect to the direction (the X direction in FIG. 7) can be obtained using the dividing pattern 37 as a reference, and the decoding success rate can be further increased.

In particular, the second specific pattern 41 is configured by arranging three dark cells, and the dividing pattern 37 has an end cell 37a in contact with the central dark cell of the second specific pattern 41, which is the second specific pattern. The pattern 41 is composed of bright cells of a different type, and the cells surrounding this end cell 37a are composed of dark cells of the same type as the cells composing the second specific pattern 41 . As a result, not only are the cells 37a at the ends of the dividing pattern 37 surrounded by cells of different types, but the cells surrounding the cells 37a at the ends of the dividing pattern 37 are all of the same type. As a result, the division pattern 37 and the second specific pattern 41 can be easily detected.

Furthermore, the third edge 34c and the fourth edge 34d are opposed in the direction along the first edge 34a and the second edge 34b (the X direction in FIG. 7) at least for the types of cells that constitute the intermediate portion. It is constructed so as to be of the same type as the cell of the division pattern 37 at the position. As a result, the cell coordinates of each cell can be accurately determined with respect to the directions along the first edge 34a and the second edge 34b, using not only the dividing pattern 37 but also the intermediate portions of the third edge 34c and the fourth edge 34d as references. can be easily obtained, and the decoding success rate can be further increased.

Note that the first edge 34a and the second edge 34b are not limited to being configured such that two second specific patterns 41 appear during repetition of the specific pattern 40, and the second specific pattern 41 is not limited to It may be configured so that one appears during repetition of the specific pattern 40, or it may be configured so that three or more appear. For example, as a first modified example of the present embodiment, three second specific patterns 41 may appear during repetition of the specific pattern 40, like a two-dimensional code 30d illustrated in FIG. . In addition, as illustrated in FIG. 8, the division pattern 37 is divided from the second specific pattern 41 of the first edge 34a to the second specific pattern 41 of the opposing second edge 34b for all the second specific patterns 41. 41, and for a portion of each second specific pattern 41, 1 from the second specific pattern 41 on the first edge 34a to the second specific pattern 41 on the opposing second edge 34b. or more may be arranged.

Further, as a second modification of the present embodiment, even if the second specific pattern 41 is not arranged like the two-dimensional code 30e illustrated in FIG. A dividing pattern 37 may be placed across the cells of the second edge 34b. In this configuration, one dividing pattern 37 may be arranged from one cell of the first edge 34a to a cell of the opposing second edge 34b, or two or more dividing patterns 37 may be arranged. Even in this case, the third edge 34c and the fourth edge 34d are arranged so that at least the types of cells forming the intermediate portion are aligned in the direction along the first edge 34a and the second edge 34b (the X direction in FIG. 9). can be configured to be of the same type as the cells of the dividing pattern 37 at the positions facing each other. As a result, the cell coordinates of each cell can be accurately determined with respect to the directions along the first edge 34a and the second edge 34b, using not only the dividing pattern 37 but also the intermediate portions of the third edge 34c and the fourth edge 34d as references. can be easily obtained, and the decoding success rate can be further increased.

[Third embodiment]
Next, a two-dimensional code according to the third embodiment will be described with reference to FIGS. 10 and 11. FIG.
The third embodiment is mainly different from the second embodiment in that the size of the code region is specified according to the position where the division pattern contacts the first edge. Therefore, the same reference numerals are assigned to substantially the same components as those of the two-dimensional code of the second embodiment, and the description thereof will be omitted.

In the present embodiment, in order to identify the size of the code area 31 (hereinafter also referred to as code size) at an early stage, the end forming one end on the first position detection pattern 33a side of the first edge 34a is The position of the dividing pattern 37 that is in contact with the first edge 34a is used with the partial cell (the dark cell in FIG. 10) Cs as a reference. Specifically, the number of cells lined up in one direction from the end cell Cs to the cell (dark cell in the center of the second specific pattern 41) with which the end cell 37a of the nearest segmented pattern 37 contacts is determined as the size identification cell. The code size is specified according to the number of cells for size specification.

In order to make it possible to specify the code size in this way, in the present embodiment, the two-dimensional code is generated so that the code size and the number of size specifying cells are in one-to-one correspondence. Specifically, as illustrated in FIG. 11A, the relationship between the code size and the number of size-specifying cells is predetermined, and the two-dimensional code according to the present embodiment can be obtained by determining the code size. When the number of size-specifying cells is uniquely determined from the code size, the division pattern 37 is generated so that the positions of the division patterns 37 in the code region 31 are determined according to the number of size-specifying cells. Note that the code size is not limited to changing only the horizontal size (the size in the direction along the first edge 34a) according to the number of size identifying cells, as illustrated in FIG. Only the size along the third edge 34c) may change according to the number of size identifying cells, or both the horizontal size and the vertical size may change according to the number of size identifying cells.

Since the two-dimensional code is generated in this way, when the two-dimensional code 30c shown in FIG. 10 is imaged, the number of size specifying cells is obtained as 20 when the code area 31 is detected, and the number of cells for size identification is obtained as shown in FIG. From the relationship shown in A), the code size is identified as 15×71. Similarly, when the number of size identification cells is obtained as 22 from the imaged two-dimensional code, the code size is identified as 15×43, and the number of size identification cells is determined from the imaged two-dimensional code to be 24. , the code size is specified as 15×99.

As described above, in the present embodiment, the code size of the code region 31 is determined by the position where the divided pattern 37 contacts the first edge 34a. By finding the position, the code size can be immediately specified. That is, when detecting the code region 31, one direction from a cell at a predetermined position such as the end cell Cs forming the end of the first edge 34a to a cell in contact with the end cell 37a of the dividing pattern 37 is detected. Since the code size of the code area 31 can be identified only by obtaining the number of cells arranged in the same line, the code size of the code area 31 can be identified at an early stage without obtaining a two-dimensional cell arrangement. Since the code size of the code area 31 can be identified in this way, even if there is a part that seems to be an aggregate of cells near the code area 31, processing for detecting the code area 31 can be performed on that part. Therefore, unnecessary processing is reduced, and processing time for reading processing can be shortened.

Note that the two-dimensional code according to the present embodiment is not limited to being generated so that the code size and the number of size-identifying cells correspond one-to-one. Many may be generated to correspond. That is, the code size should be uniquely specified from the number of size-specifying cells. For example, as exemplified in FIG. 11B, when the number of size identifying cells is obtained as 19 or 20 from the imaged two-dimensional code, the code size is identified as 15×71. Similarly, when the number of size-identifying cells is obtained as 21 or 22 from the imaged two-dimensional code, the code size is identified as 15×43, and the number of size-identifying cells is determined from the imaged two-dimensional code. is determined as 24, the code size is specified as 15×99.

In addition, the number of size-identifying cells is not limited to being obtained as the number of cells arranged in one direction from the end cell Cs of the first edge 34a to the cell in contact with the nearest end cell 37a of the dividing pattern 37. For example, it is obtained as the number of cells arranged in one direction from a predetermined cell such as a cell forming a corner of the code region 31 in the first position detection pattern 33a to a cell in contact with the end cell 37a of the division pattern 37. may

Further, the entire code size (vertical x horizontal) of the code region 31 is not limited to being associated with the number of size identifying cells. size) may be associated with the number of size identifying cells.

In addition, the code size of the code area 31 is not limited to being determined by the number of size-specifying cells as described above. The position of contact with the first edge 34a may be determined based on a predetermined position of the first position detection pattern 33a or the like and determined according to the position.

It should be noted that the present invention is not limited to the above embodiments and modifications, and may be embodied as follows, for example.
(1) The present invention is not limited to two-dimensional codes configured by arranging two types of cells, light-colored cells and dark-colored cells, in a matrix. It may be applied to a two-dimensional code arranged in a matrix.

(2) In the second edge 34b, cells at opposing positions of the portion where the specific pattern 40 is repeated on the first edge 34a and the portion where the specific pattern 40 is repeated on the second edge 34b are of the same type. It is not limited to such a configuration, and may be configured so that the cell types at opposing positions always have a predetermined relationship. For example, when two types of cells, a light cell and a dark cell, are employed, as a predetermined relationship, the dark cell is arranged as the cell on the second edge 34b facing the light cell on the first edge 34a. and light cells may be arranged as cells on the second edge 34b at positions opposite dark cells on the first edge 34a.

30, 30a to 30e Two-dimensional code 31 Code area 33a First position detection pattern 33b Second position detection pattern 34 Outer edge 34a First edge 34b Second edge 34c Third edge 34d... Fourth edge 35a, 35b, 35c, 35d... Pattern for edge 36a, 36b, 36c, 36d... Pattern for edge 37... Dividing pattern 40, 40a... Specific pattern 41... Second specific pattern

Claims (13)

A two-dimensional code in which a plurality of types of cells are arranged in a matrix within a rectangular code area,
Among the outer edges of the code region, a first edge formed by arranging the plurality of types of cells in a row is configured by repeating a specific pattern formed by arranging two or more different cells at least in an intermediate portion, A second edge formed by arranging the plurality of types of cells in a row so as to face the first edge is configured by repeating the specific pattern at least in an intermediate portion ,
A first position detection pattern used for detecting the code region is arranged at one of the corners of the code region,
the first edge is configured such that the specific pattern is repeated until the first locating pattern is reached;
At the corner of the code area diagonal to the first position detection pattern, a second position detection pattern used for detecting the code area is arranged in a different arrangement from the first position detection pattern. placed and
The two-dimensional code , wherein the second edge is configured such that the specific pattern is repeated until the second position detection pattern is reached . 2. The two-dimensional code according to claim 1, wherein at least one of the leading edge and the trailing edge of the first edge is configured to have an edge pattern different from the specific pattern. 3. The two-dimensional code according to claim 1, wherein at least one of a start end and an end end of said second edge is configured to have a pattern for an end different from said specific pattern. In the code region, there is one dividing pattern in which the cell arrangement is the same from the first edge to the second edge in the opposing direction orthogonal to the first edge and the second edge. 4. The two-dimensional code according to any one of claims 1 to 3, wherein the two-dimensional code is arranged as above. Of the outer edges of the code region, a third edge and a fourth edge that face each other so as to be orthogonal to the first edge and the second edge are at least the type of cells that constitute the intermediate portion. 5. The two-dimensional code according to claim 4, wherein the two-dimensional code is configured to be of the same type as the cells of the divided pattern located opposite each other in the direction along the first edge and the second edge. 6. The two-dimensional code according to claim 4, wherein the size of said code region is determined by the position where said dividing pattern contacts said first edge. A two-dimensional code in which a plurality of types of cells are arranged in a matrix within a rectangular code area,
Among the outer edges of the code region, a first edge formed by arranging the plurality of types of cells in a row is configured by repeating a specific pattern formed by arranging two or more different cells at least in an intermediate portion, A second edge formed by arranging the plurality of types of cells in a row so as to face the first edge is configured by repeating the specific pattern at least in an intermediate portion,
A portion where the specific pattern is repeated on the first edge and a portion where the specific pattern is repeated on the second edge are opposed in a facing direction orthogonal to the first edge and the second edge. The cells at the positions are of the same type, and
The first edge and the second edge are configured such that one or more second specific patterns different in arrangement from the specific pattern appear during repetition of the specific pattern,
The two -dimensional pattern is characterized in that the second specific pattern of the first edge and the second specific pattern of the second edge are of the same type at positions facing each other in the facing direction. code. The first edge and the second edge are each configured such that one or more of the second specific patterns appear,
dividing patterns having the same cell arrangement are arranged from the second specific pattern of the first edge to the second specific pattern of the opposing second edge in the facing direction; A two-dimensional code according to claim 7. The second specific pattern is configured by arranging three cells of the same type,
In the dividing pattern, the end cells in contact with the center cell of the second specific pattern are composed of cells of a different type from the cells constituting the second specific pattern,
9. The two-dimensional code according to claim 8, wherein the cells surrounding the end cells are of the same type as the cells forming the second specific pattern. Of the outer edges of the code region, a third edge and a fourth edge that face each other so as to be orthogonal to the first edge and the second edge are at least the type of cells that constitute the intermediate portion. 10. The two-dimensional code according to claim 8 or 9, wherein the two-dimensional code is configured to be of the same type as the cells of the dividing pattern located at opposing positions along the first edge and the second edge. . 11. The two-dimensional code according to any one of claims 8 to 10, wherein the size of said code region is determined by the position where said dividing pattern contacts said first edge. The plurality of types of cells are composed of bright cells and dark cells,
The two-dimensional code according to any one of claims 1 to 11, characterized in that said specific pattern consists of a set of said bright cells and said dark cells. The code region is rectangular,
The two-dimensional code according to any one of claims 1 to 12, wherein the first edge and the second edge constitute long sides of the code region.

Images