Two-dimensional code and code reading system
The two-dimensional code design with a detection pattern and corner markers addresses the challenge of encoding more information without reducing readability, ensuring accurate reading and efficient handling of multiple codes in a single capture.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- ASTERISK INC
- Filing Date
- 2024-12-26
- Publication Date
- 2026-07-02
AI Technical Summary
Conventional two-dimensional codes like QR Codes face challenges in encoding more information without compromising reading accuracy or expanding the display area, due to the presence of position detection patterns that compress the code area and reduce readability.
A two-dimensional code design with a detection pattern frame and markers at its corners, allowing modules to be arranged sequentially from a starting point within the code section, maintaining the code inside the detection pattern and enhancing reading accuracy.
The new code design enables accurate reading without expanding the display area, supporting multiple codes in a single image capture and maintaining high reading precision.
Smart Images
Figure JP2024046299_02072026_PF_FP_ABST
Abstract
Description
Two-dimensional code, and code reading system
[0001] The present invention relates to a two-dimensional code and a code reading system for reading information from the two-dimensional code.
[0002] Conventionally, QR Code (registered trademark) has been widely used as a two-dimensional code. Since the QR Code is excellent in that it can record more information than a one-dimensional code (barcode), it is used in various fields.
[0003] For example, a QR Code is used to authenticate the admission qualifications of visitors at an event such as an exhibition. The QR Code encodes the identification information of the visitor and is printed on the reception ticket or admission ticket. The visitor holds the QR Code up to a code reading device installed at the entrance gate of the event venue. The code reading device detects the QR Code from the reception ticket or the like presented by the visitor and reads the identification information of the visitor from the detected QR Code. The identification information read by the code reading device is compared with the identification information registered in the visitor list.
[0004] Japanese Patent Laid-Open No. 10-214317
[0005] The QR Code has a position detection pattern in order to clearly recognize the size, position, and rotation direction of the symbol within the visual field. The position detection pattern is largely arranged in the symbol portion inside the quiet zone, which is a blank portion provided in a frame shape at the outermost part of the QR Code. Therefore, it can be said that the code area in the symbol portion of the QR Code is compressed by the position detection pattern. Therefore, in order to encode more information, it is necessary to form the QR Code itself larger and include more modules (also referred to as "cells") in the symbol portion, or to form the size of each module smaller and include more modules in the symbol portion.
[0006] When the QR Code itself is enlarged as described above, the display portion on the printing medium of the QR Code is restricted, and when the cells of the QR Code are made smaller, there is a possibility that the reading accuracy of the QR Code will decrease.
[0007] Therefore, the present invention aims to provide a two-dimensional code and a code reading system that do not interfere with other display areas and have excellent reading accuracy.
[0008] To solve the above problems, the two-dimensional code according to the present invention comprises a detection pattern formed in the shape of a frame with a marker provided, and a code section provided in the part whose position is determined by the detection pattern, wherein a plurality of binarizable modules are arranged in two dimensions, and the plurality of modules are arranged sequentially from a predetermined position determined with respect to the marker as the starting point.
[0009] The code portion is characterized by being provided inside the detection pattern.
[0010] In the above-described two-dimensional code, the detection pattern is polygonal in shape, and the markers are provided at the corners of the detection pattern.
[0011] In the above two-dimensional code, the plurality of modules are characterized in that each character of the string converted into a bit sequence is modularized, and the string is encrypted.
[0012] The code reading system according to the present invention is a code reading system for reading a string from a two-dimensional code, and is characterized by comprising: an imaging unit that captures the two-dimensional code and generates an image; a detection unit that detects the two-dimensional code contained in the image; and an analysis unit that analyzes the data module contained in the detected two-dimensional code and obtains the string.
[0013] The above code reading system is characterized in that, when the image generated by the imaging unit contains multiple two-dimensional codes, the detection unit individually detects each two-dimensional code, and the analysis unit analyzes each of the detected two-dimensional codes to obtain the string of characters for each two-dimensional code.
[0014] The above code reading system is characterized by comprising a display unit that displays the acquired string and / or information corresponding to the string together with the captured two-dimensional code.
[0015] The above code reading system is characterized by comprising: a storage unit that stores the coordinates of the detected two-dimensional code in association with the acquired string; and a determination unit that determines whether or not the code has been read based on the stored coordinates.
[0016] The above code reading system is characterized by being a mobile terminal having the imaging unit, the detection unit, and the analysis unit.
[0017] In the above code reading system, the imaging unit is characterized by being a fixed-point camera.
[0018] According to the two-dimensional code and code reader of the present invention, excellent reading accuracy is achieved without compromising other display areas.
[0019] (a) A diagram showing a two-dimensional code according to an embodiment of the present invention, (b) A diagram showing another two-dimensional code according to an embodiment of the present invention. (a) A block diagram of a code reading device according to an embodiment of the present invention, (b) A functional block diagram of the code reading device. An operation flow diagram of the above code reading device. A diagram showing an example of using the two-dimensional code of this embodiment. A diagram showing an example of using the two-dimensional code of this embodiment. A diagram showing an example of using the two-dimensional code of this embodiment. (a) A diagram showing a modified two-dimensional code, (b) A diagram showing a two-dimensional code according to another modified example.
[0020] Hereinafter, an embodiment of the two-dimensional code and code reader of the present invention will be described based on the drawings.
[0021] As shown in Figure 1(a), the two-dimensional code 100 according to this embodiment is printed on the surface of a blank sheet of paper and has a rectangular shape with 11 cells x 7 cells in total. Here, a cell 110 is a grid that makes up the two-dimensional code 100, as shown by the dashed line in the figure, and is also the smallest unit of data in the code section described later. The cell 110 is square in shape, and the cell 100 is displayed in white or black. A cell 110a (data) displayed in white is a white module 110a and functions as "0". Similarly, a cell 110b (data) displayed in black is a black module 110b and functions as "1". In this way, the two-dimensional code 100 is composed of binarizable modules 110a and 110b arranged in a two-dimensional shape. Note that the two-dimensional code of the present invention is not limited to a rectangular shape with 11 cells x 7 cells, and may have a rectangular shape with more cells or fewer cells. Also, as shown in Figure 1(b), the two-dimensional code 200 may be square in shape. Furthermore, the size of the cell is not particularly limited and will be scaled according to the display size of the QR code.
[0022] The two-dimensional code 100 described above comprises a detection pattern 111 and a code section 112. The detection pattern 111 is a pattern that forms the outline of the two-dimensional code 100 and is formed in the shape of a rectangular frame with one corner (the lower right corner) recessed inward. The detection pattern 111 has a top edge length of 11 cells, a left edge length of 7 cells, a bottom edge length of 10 cells, and a right edge length of 6 cells. Because the bottom and right edges are formed with one less cell than the top and left edges, the detection pattern 111 is formed asymmetrically, and the recess 113 formed in the lower right corner functions as a marker for determining the rotation direction of the two-dimensional code 100.
[0023] The code section 112 includes a bit sequence module. In this bit sequence module, each bit of the bit sequence is represented by either a white module 110a or a black module 110b. The bit sequence module includes a modularized string formed by bit sequence conversion of information. The conversion rules for the bit sequence conversion are not particularly limited, and various conversion rules can be used. The bit sequence module comprises a module 110c corresponding to the start bit (hereinafter referred to as "start module 110c") and a module in which the bit sequence converted string is modularized (hereinafter referred to as "data module"). The start module 110c is located in the upper left cell 110 of the code section. The data modules are arranged sequentially to the right from the start module 110c, and when the rightmost cell is reached, they are arranged sequentially to the right from the cell located at the leftmost end of the next row (down row). Based on the arrangement rules of the bit sequence module, the code reader described later analyzes the bit sequence module.
[0024] The two-dimensional code 100, configured as described above, can be displayed, for example, on shelf labels in retail stores (Figure 4). The two-dimensional code 100 displayed on the shelf label contains the product's JAN code and price, which have been coded (converted to a bit string and modularized). Another example is its display on the packaging (shoe box) of products such as shoes (Figure 6). The two-dimensional code 100 displayed on the packaging contains the product's JAN code and shoe size. Furthermore, another example is its display on visitor name tags or registration slips at events such as trade shows. The two-dimensional code 100 displayed on name tags or registration slips contains coded identification information assigned to the visitor.
[0025] The above-mentioned two-dimensional code 100 is read by the code reader 300 shown in Figure 2. The code reader 300 is a device that optically reads the two-dimensional code 100 and is an information processing device such as a smartphone or tablet. Here, a smart device, which is a mobile terminal, is used for the code reader 300 that reads the two-dimensional code 100 from shelf tags on display shelves in a retail store. A code reader 300 that reads the two-dimensional code 100 from a visitor's name tag at the entrance of an event venue comprises a smart device and a stand that holds the smart device at a predetermined height, so that the smart device is upright and its camera module (described later) functions as a fixed-point camera.
[0026] As shown in Figure 2, the code reader 300 comprises a camera module 301, a touch panel display 302, a CPU 303, and a memory 304. The camera module 301 functions as an imaging unit 31 that captures images of the two-dimensional code 100 and generates images (hereinafter referred to as "captured images"). The touch panel display 302 functions as an input receiving unit that accepts touch input from the user, and also functions as a display unit 32 that displays images and information. The memory 304 functions as a storage unit 34 that stores a reading program that executes the reading of the two-dimensional code 100 and the captured images. The CPU 303, by executing the reading program, functions as a detection unit 35 that analyzes the captured images and detects the two-dimensional code 100 contained in the captured images, a specification unit 36 that identifies the marker position of the detected two-dimensional code 100, and an analysis unit 37 that analyzes the detected two-dimensional code and obtains the string of characters of the two-dimensional code. The camera module 301, the touch panel display 302, and the memory 304 are electrically connected to the CPU 303.
[0027] The operation flow of the code reading device 300 described above will now be explained with reference to Figure 3. As shown in Figure 3, the operation flow includes image acquisition processing s10, two-dimensional code detection processing s20, marker position identification processing s30, bit sequence module analysis processing s40, and display processing s50.
[0028] Image acquisition process s10 is the process of capturing an image of the two-dimensional code 100. Specifically, the CPU 303 inputs an imaging command to the camera module 301. Based on the imaging command, the camera module 301 takes images at a predetermined imaging cycle and generates an image. The camera module 301 then inputs the generated image to the CPU 303. The CPU 303 stores the image acquired from the camera module 301 in the memory 304 and executes the two-dimensional code detection process s20.
[0029] The two-dimensional code detection process s20 is a process that binarizes the captured image and detects the two-dimensional code 100 from the binarized captured image (hereinafter referred to as the "binarized image"). Specifically, the size (number of cells in the vertical and horizontal directions) of the detection pattern 111 to be read is set in advance, and the CPU 303 detects a frame-shaped character corresponding to that size in the binarized image and extracts the detected character (the image corresponding to the detection pattern 111) and the image inside it (the image corresponding to the code part 112). Hereinafter, the extracted image will be referred to as the extracted image. Here, the character corresponding to the size is, for example, a character that approximates the ratio of the number of cells on each side of the detection pattern 100 (in Figure 1(a), the top side:bottom side:left side:right side is 11:10:7:6). Furthermore, the extracted image is not limited to one; if multiple characters are detected in the binarized image, the image corresponding to each character is extracted. The CPU 303 stores the coordinates of the extracted image in the binarized image in the memory 304.
[0030] The marker position identification process s30 identifies the position of the marker 113 in the extracted image extracted in the two-dimensional code detection process s20. Marker position identification is performed, for example, by calculating the ratio of each side of the character in the extracted image and identifying the marker position based on that ratio. In this embodiment, the extracted image is then rotated so that the identified marker position is located in the lower right.
[0031] The bit sequence module analysis process s40 is a process of analyzing the bit sequence module to obtain a string. Specifically, in the extracted image, the module located diagonally opposite the marker position is designated as the start module 110c, and each module 110 is extracted based on the module arrangement rule to generate a bit sequence. Then, the bit sequence is reverse-transformed to obtain a string. The string obtained in this way is stored in memory 304. In this embodiment, the obtained string is stored in association with the coordinates of the extracted image.
[0032] The display process s50 is the process of displaying the acquired string on the touch panel display 302. Specifically, the CPU 303 displays the captured image stored in the memory 304 on the touch panel display 302. Then, it extracts the string and coordinates from the memory 304 and displays the string at the position corresponding to those coordinates. As a result, the string is displayed near the two-dimensional code 100 in the captured image. If there are multiple two-dimensional codes 100 in the captured image, the strings of multiple two-dimensional codes 100 are acquired through the two-dimensional code detection process s20, the marker position identification process s30, and the bit sequence module analysis process s40, so that multiple strings are displayed in association with the two-dimensional codes 100 in the image.
[0033] As described above, the two-dimensional code 100 of this embodiment has a detection pattern 111, and by detecting the frame-shaped character and its marker 113 corresponding to the detection pattern 111, it is possible to detect the two-dimensional code 100 and determine the direction of rotation. Furthermore, since the code portion 112 can be placed in the entire area inside the detection pattern 100 (outline), there is no compression of the data area inside the symbol portion, as is the case with conventional QR codes. Therefore, there is no need to print the two-dimensional code 100 larger than necessary, and the problem of compressing other display areas on the print medium does not occur. In addition, since there is no need to form the module smaller than necessary, there is no decrease in reading accuracy.
[0034] Furthermore, because the detection pattern 111 has a simple, roughly rectangular shape, the detection load on the detection pattern 111 is low. Therefore, even if multiple two-dimensional codes 100 exist in a single captured image, all two-dimensional codes 100 can be detected immediately. Also, because the arrangement of the bit sequence modules in the code section 112 is simple, the scanning load on the bit sequence modules is low. Therefore, the strings of multiple two-dimensional codes 100 can be acquired quickly. Accordingly, this embodiment is suitable for use in applications where multiple two-dimensional codes 100 are read at once.
[0035] For example, in the usage example where a two-dimensional code 100 is displayed on the shelf labels of the product shelves, the user does not have to read each two-dimensional code 100 on the shelf labels one by one, but can read the two-dimensional codes 100 on multiple shelf labels at once, as shown in Figure 4. In such usage examples, the code reader 300 obtains a list in advance from the POS server that associates the JAN code of a product with the price of that product, and compares the JAN code and price read from the shelf label with this list. This allows the user to confirm whether the content displayed on the shelf label is correct. The two-dimensional code 100 may also be a code that combines the JAN code and the expiration date. The code reader 300 that reads the two-dimensional code 100 displays the expiration dates of all the products that were read on the screen. This allows the user to check the expiration dates of multiple displayed products at once. The code reader 300 may also compare the current date with the read expiration date to determine if the product has expired, and may display a marker on products that have been determined to be expired. Furthermore, the code reader 300 may identify products that have a predetermined number of days remaining until their expiration date, based on the number of days remaining until the expiration date, and display a marker on those products.
[0036] Furthermore, in the example of displaying a two-dimensional code 100 on the name tags of attendees at the above event, the camera module 301 of the code reader 300 functions as a fixed-point camera that images attendees, so that the identification information of attendees can be obtained from the name tags of attendees as they arrive one after another. In such an example, the code reader 300 transmits the read identification information to a server, where the identification information is verified. This makes it possible to confirm the attendee's eligibility to attend.
[0037] Furthermore, as shown in Figure 5, a two-dimensional code 100 can be displayed on multiple test tubes. The two-dimensional code 100 encodes identification information for identifying each test tube, as well as information such as the type of liquid or other substance contained in the test tube (for example, blood type if blood is contained), and is attached to the lid of each test tube. The code reader 300 can read the two-dimensional codes 100 of these multiple test tubes all at once and display the identification information and the type of substance contained in each test tube. In this embodiment, the code reader 300 can identify types other than those specified in advance and display a mark on the test tube of the identified type.
[0038] Furthermore, as shown in Figure 6, a two-dimensional code 100 can be displayed on the product packaging. The product packaging is, for example, a box for storing shoes. In this embodiment, the two-dimensional code 100 contains coded shoe identification information and shoe size. The code reader 300 reads the two-dimensional codes 100 attached to multiple shoe boxes all at once and displays the read size near the two-dimensional code 100.
[0039] Although embodiments of the present invention have been described, the present invention is not limited to the above embodiments, and may also be modified in the following ways, for example.
[0040] [Modification 1] In the above embodiment, the start module 110c is placed in the upper left cell 110 of the code section 112, that is, the cell diagonally opposite to the marker 113, but the embodiment is not limited to this. (1) For example, the start module may be placed in the upper right cell 110 of the code section 112. In this case, the bit sequence modules are arranged sequentially to the left from the start module, and when the leftmost cell is reached, they are arranged sequentially to the left from the rightmost cell of the next row (down row). (2) Alternatively, the start module may be placed in the lower left cell 110 of the code section 112. In this case, the bit sequence modules are arranged sequentially to the right from the start module, and when the rightmost cell is reached, they are arranged sequentially to the right from the leftmost cell of the next row (up row). (3) Alternatively, the start module may be placed in the cell 110 adjacent to the marker 113 (the lower right cell in the code section). In this case, the bit sequence modules are arranged sequentially to the left from the start module, and when the leftmost cell is reached, they are arranged sequentially to the left from the rightmost cell of the next row (up row). As described above, the start module can be placed at a predetermined position with respect to the marker 113, and the bit sequence modules are arranged based on a predetermined arrangement rule with respect to the start module. The code reader 300 performs bit sequence analysis processing based on the placement position of the start module and the arrangement rule of the bit sequence modules.
[0041] [Modification 2] In the above embodiment, a marker 113 is provided in the lower right corner of the detection pattern 111. However, the position of the marker is not limited to the lower right corner and may be provided in other corners. In this case, the start module in the bit sequence module is positioned at a predetermined location with the marker provided in another corner as the base point.
[0042] [Modification Example 3] In the above embodiment, the recess of the detection pattern 111 functions as the marker 113, but the shape of the marker is not limited to a concave shape. For example, as shown in Fig. 7(a), the shape of the marker 113a may be convex. Also, as shown in Fig. 7(b), the shape of the marker 113b may be a rounded corner. That is, the shape of the marker may be any shape that can be differentiated from other multiple corners.
[0043] [Modification Example 4] The marker 113 of the above embodiment is provided at the corner of the detection pattern 111, but it is not limited to the corner and may be provided on one of the sides of the detection pattern 111. That is, the marker may be provided at a position where the rotation angle of the two-dimensional code can be determined.
[0044] [Modification Example 5] The detection pattern of the above embodiment may be a polygonal shape such as a triangular shape or a pentagonal shape, but a quadrilateral shape is preferred because the detection of the detection pattern 111 and the analysis of the bit string module are simple.
[0045] [Modification Example 6] The bit string module of the above embodiment includes a start module 110c and a plurality of data modules, but may further include a module (check module) indicating a check digit for confirming the propriety of the read bit string.
[0046] [Modification Example 7] In the above embodiment, the code reader 300 executes the two-dimensional code detection process s20, the marker position identification process s30, and the bit string module analysis process s40, but is not limited to this mode. For example, the mobile terminal includes the network communication module shown in Fig. 2, and may transmit the captured image to the server via the network communication module. In this mode, the server executes the two-dimensional code detection process, the marker position identification process, and the bit string module analysis process based on the received captured image, and transmits the acquired character string to the mobile terminal. The mobile terminal displays the character string received from the server on the display unit.
[0047] [Modification Example 8] In the above embodiment, the character string read from the two-dimensional code is stored in association with the coordinates of the two-dimensional code 100 in the captured image. However, the present invention is not limited to this aspect, and it may be stored in association with the world coordinates of the two-dimensional code 100. The world coordinates are coordinates that are developed in a plurality of captured images captured at a predetermined cycle by the camera module 301 of the code reader 300. When the CPU of the code reader 300 detects a two-dimensional code in the above two-dimensional code detection process s20, it compares the coordinates of the detected two-dimensional code with the coordinates stored in the memory. If they match, it determines that the two-dimensional code has been read. Thus, the CPU of the code reader 300 functions as a determination unit that determines whether a two-dimensional code has been read based on the coordinates stored in the memory. Also, as described above, instead of the coordinates of the two-dimensional code 100 in the captured image or the world coordinates linked to the movement of the code reader 300, the character string may be stored in association with the 3D coordinates of the two-dimensional code 100.
[0048] [Modification Example 9] The medium on which the two-dimensional code is displayed is not limited to a mount, shelf label, product package, or name tag, and can be displayed on various media. Also, the display method of the two-dimensional code is not limited to printing, and various display methods such as engraving and display on a screen can be adopted.
[0049] [Modification Example 10] In the above embodiment, the code reader scans the bit string module based on one scanning direction. However, it may scan the bit string module based on a plurality of scanning directions. For example, in the above embodiment, scanning is performed in the right direction starting from the start module (first scanning). In addition to this, scanning is performed downward starting from the start module, and when the lower end cell is reached, scanning is performed downward from the upper end cell of the next row (second scanning). Then, based on the above arrangement rule, the bits of the bit string module obtained by the second scanning are rearranged to confirm the alignment with the bit string module obtained by the first scanning. Thereby, the analysis accuracy of the bit string module can be improved.
[0050] [Modification 11] In the above embodiment, for example as shown in Figure 4, one two-dimensional code 100 is attached to one product, but multiple two-dimensional codes may be attached to one product. For example, one product may be attached to a first two-dimensional code that encodes the JAN code, a second two-dimensional code that encodes the product price, and a third two-dimensional code that encodes the expiration date. The code reader 300 can read these multiple two-dimensional codes all at once and display the read information (JAN code, product price, expiration date) or transmit the read information to a server.
[0051] [Modification 12] In addition to the usage of the above embodiment, the two-dimensional code 100 and code reader 300 can be used for receiving checks when receiving goods and for shipping checks when shipping goods. In this embodiment, the two-dimensional code 100 is a coded representation of the JAN code or invoice number. The code reader performs receiving and shipping processes based on the JAN code or invoice number read from the two-dimensional code 100 attached to the goods being received / shipped. Alternatively, inventory can be taken using the two-dimensional code 100 and code reader 300. In this embodiment, the two-dimensional code 100 is a coded representation of the JAN code of the goods. The code reader 300 performs inventory processing based on the read JAN code.
[0052] 100 Two-dimensional code 110a White module 110b Black module 111 Detection pattern 112 Code section 113 Marker 200 Two-dimensional code 300 Code reader
Claims
1. A two-dimensional code comprising: a detection pattern formed in the shape of a frame with a marker provided; and a code section provided in the part whose position is determined by the detection pattern, wherein a plurality of binarizable modules are arranged in a two-dimensional manner, and the plurality of modules are arranged sequentially from a predetermined position determined with respect to the marker as the starting point.
2. The two-dimensional code according to claim 1, characterized in that the code portion is provided inside the detection pattern.
3. The two-dimensional code according to claim 1, wherein the detection pattern is polygonal in shape, and the markers are provided at the corners of the detection pattern.
4. The two-dimensional code according to claim 1, wherein each of the plurality of modules is a modularized character of a string converted into a bit string, and the string is encrypted.
5. A code reading system for reading a character string from a two-dimensional code as described in claim 1, comprising: an imaging unit that captures the two-dimensional code and generates an image; a detection unit that detects the two-dimensional code contained in the image; and an analysis unit that analyzes the data module contained in the detected two-dimensional code and obtains the character string.
6. The code reading system according to claim 5, characterized in that, if the image generated by the imaging unit contains multiple two-dimensional codes, the detection unit individually detects each two-dimensional code, and the analysis unit analyzes each of the detected two-dimensional codes to obtain the string of characters for each two-dimensional code.
7. The code reading system according to claim 5, further comprising a display unit that displays the acquired string and / or information corresponding to the string together with the captured two-dimensional code.
8. The code reading system according to claim 5, comprising: a storage unit that stores the coordinates of the detected two-dimensional code in association with the acquired string; and a determination unit that determines whether or not the code has been read based on the stored coordinates.
9. The code reading system according to claim 5, wherein the mobile terminal has the imaging unit, the detection unit, and the analysis unit.
10. The code reading system according to claim 5, characterized in that the imaging unit is a fixed-point camera.