JP2000057250A - Reading method for two-dimensional code - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reading method for a two-dimensional code which prevents the two-dimensional code from being misread owing to a stain nearby the two-dimensional code. SOLUTION: A reference line decision means 8 which has cells arranged in matrix is placed over image information IP expanded in an image memory and then rotated to estimate a row ny where more than a specific number of black cells are successive on the reference line decision means 8 as an X- axial reference line. Lines ny-1 to ny-4 and ny+1 to ny+4 above and below the estimated X-axial reference line ny are scanned respectively and the estimated X-axial reference line ny is determined as an X-axial reference line Lx on condition that while more than a specific number of black cells are present on the rows ny+1 to ny+4 on one side of the scanning, more than a specific number of black cells are not present on the rows ny-1 to ny-4 on the other side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reading a two-dimensional code, and more particularly to a method for preventing a two-dimensional code reading error caused by dirt near a two-dimensional code to be read. And a method for reading a two-dimensional code.

[0002]

2. Description of the Related Art Recently, in the technical field of automatic recognition codes,
Interest in two-dimensional codes is rapidly increasing, and according to this, a data density several tens to hundreds of times higher than that of bar codes (one-dimensional codes), which has conventionally been the mainstream of automatic recognition codes, has been found. Can have. For example, if the two-dimensional code is printed directly on a product or the like, or a label on which the two-dimensional code is printed is attached, it can be used for various purposes such as process management, inventory management, and quality management.

FIG. 19 is an explanatory diagram schematically showing a configuration of a matrix type code (two-dimensional matrix code) as an example of a two-dimensional code. This two-dimensional code c
p is a matrix type CP code (Computer P
urpose Code) (registered trademark of Japan ID Tech Co., Ltd.)
Is shown. The CP code cp has a configuration in which there are 144 cells of 12 rows × 12 columns, which are called cells. Further, the code cp is provided with an X-axis reference line Lx and a Y-axis reference line Ly.

Further, the X-axis reference line Lx includes:
Tx,..., Tx are provided at regular intervals. Also, timing marks Ty,. , Ty. An auxiliary mark (also called a corner mark) Mc is provided at a predetermined position in a region sandwiched between the X-axis reference line Lx and the Y-axis reference line Ly.

[0005] Various information that has been two-dimensionally coded is written in an area between the X-axis reference line Lx and the Y-axis reference line Ly on the side where the auxiliary mark Mc is provided. Furthermore, this C
The P code cp is provided along timing marks Tx,..., Tx provided at regular intervals (here, every other cell) along the X-axis reference line Lx, and along the Y-axis reference line Ly. At regular intervals (here 1
Timing mark T added to every other cell)
By using y,..., and Ty, the coordinate position of each cell (excluding the auxiliary mark Mc) formed by each row and each column is expressed by:
Since it is specified, even if the two-dimensional code cp is distorted, the coordinate position can be specified accurately.

In the CP code cp, the auxiliary mark Mc is provided, so that the two-dimensional code cp is supposed to be pasted upside down, left or right reversed, or upside down. Can read the information described in the CP code cp. In this example, each cell includes a plurality of pixels (for example, 4 pixels).
If the number of black pixels is equal to or more than a predetermined number, it is determined to be a black cell, and if the number of black pixels is less than a predetermined number, it is determined to be a white cell, and each cell forms bit information (binary data). Have been.

[0007] The bit information can be used to represent not only alphanumeric characters, kanji, and kana, but also various languages around the world. For example, when a hexadecimal number is represented by four cells and a JIS kanji code is represented by 16 cells, the kanji character “1” is represented by the code “306C”, the kanji character “2” is represented by the code “4673”, and the code “ "3B30" indicates the kanji character "3".

In addition, the bit information can include error correction data at a predetermined rate in addition to the user data, so that, for example, the two-dimensional code cp becomes dirty, Even if it is damaged, data (user data) can be automatically restored. Further, even if the amount of user data changes, the ratio of the data for error correction only has to be changed, so that there is an excellent advantage that the size of the two-dimensional code cp can be kept constant. For example,
JP-A-64-86289, JP-B-8-21054
Reference).

[0009]

However, in the CP code cp, at least the X-axis reference line L
If the x- or Y-axis reference line Ly cannot be specified, the two-dimensional code cannot be decoded. If the X-axis reference line Lx or the Y-axis reference line Ly cannot be specified, it is processed as a reading error. In this case, there is a problem that the product or the like is treated as a defective product due to a two-dimensional code reading error even though the product or the like has no problem at all.

FIG. 20 is an explanatory diagram schematically showing an example of a two-dimensional code to which dirt is treated as such a reading error. In the CP code cp, on the side of the X-axis reference line Lx opposite to the side where the timing marks Tx,..., Tx are provided, so that the X-axis reference line Lx or the Y-axis reference line Ly is easily specified. A so-called all-white line region Rxw is provided along the X-axis reference line Lx.

Similarly, for the Y-axis reference line Ly,
On the side opposite to the side where the timing marks Ty,..., Ty are provided, a so-called all-white line area Ryw is provided along the Y-axis reference line Ly. However, as shown in FIG. 20, when the dirt Sp is attached so as to overlap the all white line region Rxw, the dirt Sp is imaged as a black pixel by solid-state imaging means such as a CCD camera. Then, the X-axis reference line Lx cannot be specified. In this case,
It will be processed as a reading error.

Similarly, when the stain Sp is attached so as to overlap the all white line area Ryw, this stain S
If p is imaged as a black pixel by solid-state imaging means such as a CCD camera, the Y-axis reference line Ly
Cannot be specified, and in this case, it is also processed as a reading error. Conventionally, the decoding of the CP code cp is performed by analyzing the entire image information captured by a solid-state imaging unit such as a CCD camera.
As described above, when an image is captured by a solid-state imaging device such as a CCD camera, the image captured by the solid-state imaging device must be analyzed at a location other than the location where the two-dimensional code cp is captured. There is a problem that the amount is large and it takes time to decode the two-dimensional code cp.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and prevents a reading error of a two-dimensional code caused by a stain existing near a two-dimensional code to be read. The present invention provides a method for reading a two-dimensional code as described above, and can prevent a two-dimensional code reading error caused by dirt existing near a two-dimensional code to be read, and can prevent the two-dimensional code from being read. An object of the present invention is to provide a method of reading a two-dimensional code, which can read at a high speed.

[0014]

According to a first aspect of the present invention, there is provided a method of reading a two-dimensional code, wherein an X-axis reference line and a Y-axis reference line are provided in an L-shape, and wherein the X-axis reference line and the Y-axis reference line are provided. This is a method of reading a two-dimensional code in which predetermined information is converted into a two-dimensional code and recorded in an area sandwiched between the axis reference lines, and a predetermined area including the two-dimensional code is imaged by solid-state imaging means. An imaging step, an expansion step of expanding image information captured by the solid-state imaging means in an image memory, and a reference line determination scale means in which a plurality of cells are arranged in a matrix in the image information expanded in the image memory. After overlapping, this is rotated so that a predetermined predetermined number of cells continuously When the black line appears as a black cell, the rotation of the reference line discrimination scale means is stopped, and a row in which black cells appearing on any line of the reference line discrimination scale means are connected to the X axis reference line or the Y axis reference line. A reference line estimating step of estimating one of the X-axis reference line and a predetermined number of lines on one side around the estimated reference line estimated to be one of the X-axis reference line and the Y-axis reference line A predetermined number of lines on the other side are scanned, and the number of black cells or the number of white cells for each of the plurality of lines on one side and each of the plurality of lines on the other side are summed up in cell units provided in the reference line determination scale means. A predetermined number of lines on one side around the estimated reference line and the estimated reference When the number of black cells or white cells is equal to or greater than a predetermined number on one of the predetermined number of lines on the other side around the sense line, and the number of black cells or white cells is not equal to or greater than a predetermined number on the other side. And a reference line determining step of determining the estimated reference line as the X-axis reference line or the Y-axis reference line.

The term “black” or “white” used in the present specification defines a case where “black” or “white” is determined after binarization. It is not limited to “black” or “white”. For example, if the two-dimensional code is represented by blue on a white background,
Defined as "black".

If the two-dimensional code is represented by black on a white background, black stains become a problem, so the two-dimensional code is read with black and black cells and black pixels. Conversely, 2
When the dimensional code is represented by white on a black background, white stains become a problem, so the two-dimensional code is read with white cells and white pixels. When the two-dimensional code is represented by black on a white background, in the two-dimensional code reading method, the reference line is estimated by the reference line estimation step, and the estimated reference line estimated by this step is further estimated. With respect to the center, scanning is performed for each of a predetermined number of lines on one side and a predetermined number of lines on the other side, and thus a predetermined number of lines on one side and a predetermined number of lines on the other side are scanned. The number of black cells is summed for each of the cells provided in the reference line discriminating means, and the number of black cells is equal to or more than a predetermined number in a predetermined number of lines on one side of the estimated reference line, and When the number of black cells does not exceed a predetermined number in the number of lines, the estimated reference line is set to the X-axis reference line or the Y-axis reference line. It is provided a reference line determination step of determining.

Accordingly, even if the dirt is superimposed on the area of the all white line provided along the opposite side of the X-axis reference line on which the timing mark is provided, the X-axis reference line is specified. can do. Similarly, the Y-axis reference line is specified even if the stain adheres to the area of the all white line provided along the side opposite to the side on which the timing mark is provided of the Y-axis reference line. be able to.

As a result, even if dirt exists near the two-dimensional code to be read, no two-dimensional code reading error occurs. In the case where the two-dimensional code is represented by white on a black background, in the two-dimensional code reading method, a reference line is estimated by a reference line estimation step. With the line as a center, each of a predetermined number of lines on one side and a predetermined number of lines on the other side is scanned, and a predetermined number of lines on one side and a predetermined number of lines on the other side are scanned as described above. The number of white cells for each of the lines is summed up in cell units provided in the reference line discriminating means, and a predetermined number of lines on one side of the estimated reference line has a predetermined number of white cells or more, and the other side has When the number of white cells does not exist in the predetermined number of lines, the estimated reference line is set to the X-axis reference line or the Y-axis reference line. Is provided with a reference line determining step of determining the in-.

Thus, even if dirt adheres to the area of the all black lines provided along the opposite side of the X-axis reference line on which the timing mark is provided, the X-axis reference line is specified. can do. Similarly, the Y-axis reference line is specified even if the stain adheres to the area of the all black line provided along the side opposite to the side where the timing mark is provided on the Y-axis reference line. be able to.

Thus, even if dirt exists near the two-dimensional code to be read, no two-dimensional code reading error occurs. In the method for reading a two-dimensional code according to claim 2, the X-axis reference line and the Y-axis reference line are provided in an L-shape, and are arranged in a region sandwiched between the X-axis reference line and the Y-axis reference line.
A method of reading a two-dimensional code in which predetermined information is converted into a two-dimensional code and recorded, wherein a predetermined area including the two-dimensional code is imaged by solid-state imaging means in which a plurality of photoelectric conversion elements are arranged in a matrix. An image capturing step, and an expanding step of expanding the image information captured by the solid-state image capturing means into an image memory; and a row unit in units of photoelectric conversion elements arranged in a matrix of the solid-state image capturing means. In each case, the number of black pixels or white pixels is summed, and black pixel information or white pixel information is determined from the first row and the last row of the row including the predetermined number of black pixels or white pixels. The number of black pixels or the number of white pixels is determined for each column, in units of photoelectric conversion elements arranged in a matrix of solid-state imaging means, by determining a row serving as a center line of an area including the number of pixels or more. The number of black pixels or white From the first column and the last column of the column in which the prime number is equal to or more than a predetermined number, a column serving as the center line of the region including the black pixel information is equal to or more than the predetermined number is determined. 2 to be read in advance from the image information developed in the image memory, centering on the intersection of the columns
After superimposing a reference line discrimination scale means in which a plurality of cells are arranged in a matrix on the image information extraction step of extracting an area slightly larger than the area of the dimensional code and the image information extracted by the image information extraction step ,
When the predetermined number of cells continuously appear as black cells on one of the lines of the reference line discrimination scale means, the rotation of the reference line discrimination scale means is stopped. A reference line estimating step of estimating a continuous line of black cells or white cells appearing on any line of the discrimination scale means as an X-axis reference line or a Y-axis reference line; Scanning each of a predetermined number of lines on one side and a predetermined number of lines on the other side around the estimated reference line estimated to be one of the axis reference lines, and a plurality of lines on one side And the number of black or white cells for each of the multiple lines on the other side The sum is calculated in units of cells provided in the in-determination scale means, and a black cell is placed on one of a predetermined number of lines on one side around the estimated reference line and a predetermined number of lines on the other side around the estimated reference line. A reference line determining step of determining the estimated reference line as an X-axis reference line or a Y-axis reference line when the number is equal to or more than a predetermined number and the other side does not have the predetermined number of black cells or white cells. Prepare.

According to the two-dimensional code reading method of the present invention, as a pre-processing step of the reference line estimating step, an area estimated to include the two-dimensional code from image information taken by the solid-state imaging means is provided. Since the two-dimensional code is read from the extracted small information, the two-dimensional code can be decoded at a high speed by the amount of data used for decoding.

In the image information extracting step, 2
The area estimated to contain the dimensional code is obtained by converting the image information expanded in the image memory into photoelectric conversion elements arranged in a matrix of the solid-state imaging means, and for each row, the number of black pixels or white pixels. From the first row and the last row of the row in which the number of black pixels or white pixels is equal to or more than a predetermined number, a row serving as a center line of an area including a predetermined number or more of black pixel information or white pixel information is determined. Then, the image information developed in the image memory is summed up for the number of black pixels or white pixels for each column unit for each photoelectric conversion element arranged in a matrix of the solid-state imaging means, and the number of black pixels or white pixels is calculated. From the first column and the last column of the columns included in the predetermined number or more, a column serving as a center line of an area including black pixel information or white pixel information in a predetermined number or more is determined. Is the image information developed in the image memory centered on the intersection of the line columns , So that cut out slightly larger area than the area of the two-dimensional code to be read in advance.

As a result, the two-dimensional code is included in the cut-out area with a high probability, so that the two-dimensional code is not included in the cut-out area, or only a part thereof is included. It is unlikely that such inconveniences occur.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for reading a two-dimensional code according to the present invention will be described in more detail with reference to the drawings. In the following description, a case where a two-dimensional code is attached in black on a white background will be described as an example. (First Embodiment of the Invention) FIG. 1 is an overall configuration diagram schematically illustrating a two-dimensional code reading apparatus for implementing a two-dimensional code reading method according to the present invention.

In the following description, in order to facilitate the explanation, the two-dimensional code reader 1 is attached to a container containing a product such as a medicine by attaching a label with a two-dimensional code to the container. An example in which containers are sorted based on information of a two-dimensional code will be described. More specifically, for example, time information such as a manufacturing date, an expiration date, etc. is included in a two-dimensional code attached to a label attached to a container containing a product such as a drug, and Sorting such as discarding products that have passed a predetermined time from the date or discarding products that have already expired,
Product information such as product number and lot number is included in a two-dimensional code attached to a label attached to a container containing a product such as a drug, and a product determined to be defective is included in the manufacturing information. An example will be described in which the present invention is applied to a case where sorting based on discarding is performed.

The two-dimensional code reader 1 includes an arithmetic processing unit 2, a solid-state imaging unit 3 such as a CCD camera connected to the arithmetic processing unit 2 via a signal line, and a signal line to the arithmetic processing unit 2 via a signal line. And a decoder 4 connected thereto. still,
In this example, as the arithmetic processing means 2, a general-purpose arithmetic processing means having a screen display means (CRT) 2a, an external input means (keyboard or mouse) 2b, etc., which is called a personal computer, is used. , The arithmetic processing means 2 includes:
The printer 5 is connected.

A predetermined operation program for sorting containers is stored in advance in the storage section of the arithmetic processing means 2. The two-dimensional code reader 1 sorts containers according to the operation program. I have. When the basic program software Fa is incorporated in the arithmetic processing means 2, the arithmetic processing means 2 can be used as a control unit for controlling the whole of the two-dimensional code reader 1. When the dictionary software Fb is incorporated in the arithmetic processing means 2, characters and symbols input from the external input means 2b of the arithmetic processing means 2 can be converted into two-dimensional codes, which can be recorded by the printer 5 and printed out. I have.

FIG. 2 is an enlarged perspective view schematically showing one of the containers to be sorted. A label P having a two-dimensional code cp is attached to a predetermined position on the container V. Have been. In this example, each of the plurality of containers V,..., V to which each of the labels P to which the two-dimensional code cp is attached is placed on a conveying means 6 such as a belt conveyor, and the imaging point Rp , And the two-dimensional code cp attached to each of the containers V,..., V is imaged by the solid-state imaging means 3 at the imaging point Rp.

More specifically, the imaging point Rp
A container detecting means 7 including an infrared light emitting element 7a and an infrared light receiving element 7b is provided at a position on the upstream side of. When the power of the two-dimensional code reader 1 is turned on, the infrared light emitting element 7a emits infrared light toward the infrared light receiving element 7b. The infrared light receiving element 7b is connected to the arithmetic processing unit 2, and while receiving infrared light emitted from the infrared light emitting element 7a,
The transmission of the received light signal to the processing unit 2 is stopped when the infrared light emitted from the infrared light emitting element 7a is no longer received. ing.

The solid-state image pickup means 3 includes a flash means 3a. When a command signal to release a shutter is received from the arithmetic processing unit 2, the flash means 3a is turned on and, at the same time, the shutter is released. Image information captured by the solid-state imaging means 3 is sent to the arithmetic processing device 2 and temporarily stored in a storage unit of the arithmetic processing device 2. The image information sent to the arithmetic processing device 2 further includes , To the decoder 4, where the two-dimensional code is, for example, J
Information converted into an IS code or the like and converted into a JIS code or the like by the decoder 4 is transmitted to the arithmetic processing unit 2.

Hereinafter, the operation of the two-dimensional code reader 1 will be described. First, the two-dimensional code reader 1
When the power is turned on, the transport means 6 starts to move, and the containers V,..., V placed on the transport means 6 are transported to the imaging point Rp side. Also, the infrared light emitting element 7a
Irradiation of infrared light to the infrared light receiving element 7b is started.

The infrared light receiving element 7b is
While receiving the infrared rays emitted from a, the light receiving signal is continuously transmitted to the arithmetic processing means 2 at all times. The arithmetic processing unit 2 determines that there is no object (the container V in this example) to be imaged by the solid-state imaging unit 3 on the transporting unit 6 while receiving the light receiving signal from the infrared light receiving element 7b. On the other hand, when the light receiving signal from the infrared light receiving element 7b stops, it is determined that the object (in this example, the container V) to be imaged by the solid-state imaging means 3 has been conveyed to the imaging point Rp side, and the light receiving signal stops. After a lapse of a predetermined time from the time, the conveying means 6
When the container V conveyed above reaches the imaging point Rp, a command signal for releasing the shutter of the solid-state imaging means 3 is given by:
The data is transmitted to the solid-state imaging means 3.

The solid-state image pickup means 3 is provided from the arithmetic processing means 2
Upon receiving a command signal to release the shutter, the flash is fired and the shutter is released, so that the imaging point Rp
The image of the label P of the container V located at the position. FIGS. 3 and 4 show the operation processing means 2 of the two-dimensional code reader 1.
FIG. 7 is a processing procedure diagram schematically illustrating an example of a two-dimensional code reading operation performed by the decoder 4.

First, in the step shown in FIG. 3A, image information IP picked up by the solid-state image pickup means 3 is developed in an image memory of a storage unit (not shown) of the arithmetic processing means 2. Here, in order to facilitate the explanation, the solid-state imaging means 3
However, a case where the image information IP as shown in FIG. 5 is imaged will be described as an example. In this example, the image information IP captured by the solid-state imaging unit 3 is converted into an electric signal by setting a black pixel as a high potential and a white pixel as a low potential,
The coordinates of a plurality of photoelectric conversion elements arranged in a matrix of the solid-state imaging means 3 are temporarily stored in an image memory of a storage unit of the arithmetic processing means 2.

The image information IP developed in the image memory of the storage unit of the arithmetic processing means 2 is further transmitted to the decoder 4. The image information IP transmitted to the decoder 4 is temporarily stored in an image memory of a storage unit of the decoder 4. Decoder 4
In the step shown in FIG. 3B, reference is made to a reference in which a plurality of electrically created cells are arranged in a matrix as shown in FIG. 6 in the image information IP temporarily stored in the storage unit. The line discrimination scale means 8 is overlaid (see FIG. 7).

In this example, a plurality of cells ce,...
The resolution of ce is lower than that of the solid-state imaging means 3. More specifically, in this example, the X-axis reference line Lx captured by the solid-state imaging unit 3 is approximately two rows, and the Y-axis reference line Ly is approximately two columns. , A black pixel (high-potential region) indicating information is determined by four cells.

The resolution of the reference line discrimination scale means 8 is appropriately selected based on the size of the two-dimensional code imaged by the solid-state imaging means 3. Next, in the step shown in FIG. 3C, the decoder 4 replaces the reference line discrimination scale means 8 with the cells ce,.
Rotate until a predetermined number of predetermined cells continuously appear as black cells on the line formed by ce.

In this example, the X-axis reference line Lx can be specified by approximately 28 cells of one line formed by the cells ce,..., Ce of the reference line discrimination scale means 8. The reference line determination scale unit 8 is rotated until about 28 black cells are arranged on one line in units of cell ce of the reference line determination scale unit 8.

FIG. 8 schematically shows a state where about 28 black cells are arranged on one line in units of cells ce of the reference line discrimination scale means 8. In this example, the cell c of the reference line discrimination scale means 8 is used.
In this example, the rotation operation of the reference line determination scale means 8 is stopped in a state where about 28 black cells are arranged on one line in units of e. Cell c of reference line discrimination scale means 8, which is used to determine that the operation is to be stopped
The predetermined number of cells in which black cells are arranged in one line in e units is appropriately selected based on the size of the two-dimensional code imaged by the solid-state imaging means 3.

When a predetermined number of black cells are arranged on one line in units of cell ce of the reference line discrimination scale means 8, the decoder 4 stops the rotation of the reference line discrimination scale means 8, and turns off the reference line discrimination scale means 8. For each cell ce, a line in which a predetermined number of black cells are arranged on one line (line ny shown in FIG. 9) is estimated as an X-axis reference line Lx.

Next, after estimating the X-axis reference line Lx in this way, in the step shown in FIG. 4A, the decoder 4 has a predetermined angle with respect to the estimated X-axis reference line Lx. .., 9 are sequentially superimposed, and a line in which a predetermined number of black cells continuously appear along a line having a predetermined angle is specified as a Y-axis reference line Ly. .

The estimated X-axis reference line Lx of the image information temporarily stored in the storage unit of the decoder 4
The angle θ between the estimated X-axis reference line Lx and the specified Y-axis reference line Ly, with the intersection of the specified Y-axis reference line Ly as the origin,
The correction is made so that tan θ = ∞. Next, the decoder 4 sums up the number of black cells for each of several rows above and below the estimated X-axis reference line Lx (in this example, the line ny shown in FIG. 9).

Here, in order to facilitate the description, four lines are arranged in a row by four lines above and below the line ny.
An example in which the number of black cells is totaled will be described. In this example, as shown in FIG.
There are eight, and there is a total of one black cell in the ny-1 row,
The ny-2 row has a total of one black cell, the ny-3 row has a total of 0 black cells, and the ny-4 row has a total of 0 black cells. ing. In the ny + 1 row, there are a total of 28 black cells (corresponding to the number of cells of the X-axis reference line Lx), and in the ny + 2 row, there are a total of 14 black cells (cells of the Y-axis reference line Ly). Number and the number of cells of the timing mark Tx), and a total of 14 black cells (Y
(Corresponding to the sum of the number of cells of the axis reference line Ly and the number of cells of the timing mark Tx), and ny +
In the fourth row, 14 black cells (Y-axis reference line L
(equivalent to the sum of the number of cells of y and the number of cells indicating information)
An example is shown.

Here, the two-dimensional code cp is composed of an X-axis reference line Lx, a Y-axis reference line Ly, timing marks Tx,.
, Ty, black pixels serving as information, and auxiliary marks Mc, are sandwiched between the X-axis reference line Lx and the Y-axis reference line Ly, and on the side where the auxiliary marks Mc are provided. There is always a predetermined number or more of black cells in the area.

Therefore, if the minimum number of black cells existing for each row passing through the area of the code cp is set as the threshold value Yth, the estimated reference line ny estimated to be the X-axis reference line Lx will be A predetermined number of lines on one side of the periphery and a predetermined number of lines on the other side are scanned, and the number of black cells for each of the plurality of lines on one side and the plurality of lines on the other side is sent to the reference line determination scale means. The total number of black cells is determined in one of a predetermined number of lines on one side around the estimated reference line ny and a predetermined number of lines on the other side around the estimated reference line ny. If the number of black cells is equal to or greater than (the number of black cells / row ≧ threshold Yth) and the number of black cells is less than the predetermined number (the number of black cells / row <threshold Yth) on the other side, the estimation is performed. The reference line ny may determine the X-axis reference line Lx.

For easy understanding, this will be specifically described based on an example shown in FIG. In the example shown in FIG.
Since the axis reference line Ly is identified in two columns,
There are always two or more black cells in the area of the two-dimensional code cp. Therefore, the threshold value Yth of the minimum number of black cells that is
(Yth = 2), the X-axis reference line Lx
, A predetermined number of lines on the other side around the estimated reference line ny (in this example, ny-1, row ny-2, ny-3, and ny-4)
Row) and a predetermined number of lines on the other side (ny + 1 in this example)
When scanning is performed for each of the rows, ny + 2 rows, ny + 3 rows, and ny + 4 rows, in this example, a total of 4 rows of a plurality of rows on the other side (ny-1, row ny-2, ny-3, and ny-4 rows) ), The number of black cells in each line is
It is smaller than the threshold Yth (in this example, Yth <2).

Further, a plurality of lines (ny + 1) on one side
Row, ny + 2 row, ny + 3 row and ny + 4 row, total 4
When scanning is performed for each of the rows, the number of black cells in each of the multiple lines on one side (ny + 1 row, ny + 2 row, ny + 3 row, and ny + 4 row in total of 4 rows) is as follows.
Since the threshold value is equal to or more than the threshold value Yth (Yth ≧ 2 in this example), the estimated reference line ny estimated to be the X-axis reference line Lx can be determined to be the X-axis reference line Lx.

Next, in the step shown in FIG. 4B, the decoder 4 exists on the other side where the number of black cells is less than the predetermined number (in this example, each of the ny-1 row and the ny-2 row). Each of the black cells cb and cb) is determined to be dirty, and FIG.
In the step shown in (c), each of the black cells cb, cb determined to be dirty is converted into a white cell, and an image information correction step of correcting image information developed in the image memory of the decoder 4 is performed. Based on the image information corrected by the information correction step, the two-dimensional code information recorded in the area sandwiched between the X-axis reference line Lx and the Y-axis reference line Ly is converted into, for example, JIS.
Decode into code.

As described above, the decoder 4
The information decoded from the dimensional code information is sent to the arithmetic processing means 2
, And based on information decoded from the two-dimensional code information by the operation program stored in advance in the storage unit of the arithmetic processing means 2, the containers V,.
V is sorted. In this two-dimensional code reading method,
A reference line ny is estimated by a reference line estimation step, and a predetermined number of lines (ny + 1 rows, ny + 1 rows, ny + 1 rows in this example) on one side of the estimated reference line ny estimated in this step are centered on the estimated reference line ny.
+2 rows, ny + 3 rows, and ny + 4 rows, for a total of 4 rows) and a predetermined number of lines on the other side (in this example, ny−1 rows, ny
And a predetermined number of lines on one side (in this example, ny + 1 rows, ny + 2 rows, n
y + 3 rows, ny + 4 rows, a total of 4 rows) and a predetermined number of lines on the other side (in this example, ny-1 rows, ny-2 rows, ny- rows)
The number of black cells for each of the three rows and the ny-4 rows (total of four rows) is summed for each cell provided in the reference line discriminating means, and a predetermined number of lines on one side of the estimated reference line ny (in this example, in this example) , Ny + 1 row, ny + 2 row, n
The number of black cells is equal to or more than a predetermined number (the number of black cells / row ≧ threshold Yth (in this example, the number of black cells / row ≧ 2)) in y + 3 rows and ny + 4 rows (total of 4 rows), and the predetermined number on the other side is (In this example, ny-1 row, ny-2 row, ny-3 row, ny
-4 rows, the total number of black cells is less than a predetermined number (the number of black cells / row <threshold Yth (in this example, the number of black cells / row <2))
If there is, the estimated reference line ny is determined as the X-axis reference line Lx.

Thus, for example, the dirt Sp adheres to the region Rxw of the all-white line provided along the X-axis reference line Lx along the side opposite to the side where the timing marks Tx,..., Tx are provided. Even so, the X-axis reference line Lx can be specified. Although the method of determining the X-axis reference line Lx has been described above, the method of determining the Y-axis reference line Ly can also be determined by replacing the rows with the columns and the columns with the rows. Can be determined by a method similar to the method of determining

Accordingly, of the Y-axis reference line Ly,
The Y-axis reference line Ly can be specified even when the stain Sp is attached so as to overlap the region Ryw of the all white line provided along the side opposite to the side where the timing marks Ty,. . As a result, even if dirt exists near the two-dimensional code cp to be read, no two-dimensional code reading error occurs. (Embodiment 2) FIGS. 10 and 11 schematically show another example of a two-dimensional code reading operation performed by the arithmetic processing means 2 and the decoder 4 of the two-dimensional code reader 1 shown in FIG. It is a processing procedure figure shown.

First, in the step shown in FIG. 10A, image information picked up by the solid-state imaging means 3 is developed in an image memory of a storage unit (not shown) of the arithmetic processing means 2.
Here, for ease of explanation, the solid-state imaging means 3
An example in which image information as shown in FIG. 12 is captured will be described. In this example, the image information captured by the solid-state imaging unit 3 is converted into an electric signal with the black pixel as a high potential and the white pixel as a low potential and arranged in a matrix of the solid-state imaging unit 3. The coordinates of the plurality of photoelectric conversion elements are temporarily stored in the image memory of the storage unit of the arithmetic processing unit 2.

The image information developed in the image memory of the storage unit of the arithmetic processing means 2 is further transmitted to the decoder 4.
The image information transmitted to the decoder 4 is temporarily stored in an image memory of a storage unit of the decoder 4. The steps up to the steps described above are the same as those shown in FIG.
The process is the same as the process up to the step shown in (a), but in the second embodiment of the invention, the following steps are different from the steps shown in the first embodiment of the invention.

That is, in the step shown in FIG. 10B, the decoder 4 uses the image information IP temporarily stored in the storage unit to store the area Ra that will contain the two-dimensional code cp.
Is to be cut out. This image information extracting step will be described in more detail with reference to FIG. First, an image is taken by the solid-state imaging means 3 and the
The image information developed in the image memory of
For each photoelectric conversion element arranged in a matrix of
Sum the number of black pixels.

Next, based on the arithmetic mean ((nys + nye) / 2) of the first row nys and the last row nye of the row containing the black pixel number of a predetermined number or more, the area containing the predetermined number of black pixel information is obtained. Is determined. Also, the first column nx of a row in which the number of black pixels is equal to or more than a predetermined number
s and the arithmetic mean of the last column nxe ((nxs + nx
e) / 2), a column nxc which is a center line of an area including a predetermined number or more of black pixel information is determined.

Next, an intersection cg1 of the row nyc serving as the center line and the column nxc serving as the center line is obtained. Next, the intersection cg1
As a means for cutting out a predetermined two-dimensional code area centered on the image, an image cut-out means 10 for cutting out an area slightly larger than the two-dimensional code area formed by electrical means as shown in FIG. Is the center of gravity cg2
Are superimposed so as to coincide with the intersection cg1, and the image cutout unit 10 cuts out a region Ra that will contain the two-dimensional code cp (see FIG. 14).

Next, as shown in FIG. 15, a plurality of electrically created cells arranged in a matrix having a size large enough to analyze a region Ra that will contain the two-dimensional code cp are arranged. Reference line discrimination scale means 8A
Is superimposed on the cut-out region Ra that will contain the two-dimensional code cp such that the center cg3 of the reference line discrimination scale means 8A coincides with the center cg1 of the region Ra (see FIG. 16).

Also in this example, a plurality of cells ce,... Arranged in a matrix of the reference line determination scale means 8A.
The resolution of ce is lower than that of the solid-state imaging means 3. More specifically, also in this example, the X-axis reference line Lx captured by the solid-state imaging unit 3 is approximately two rows, and the Y-axis reference line Ly is approximately two columns. , A black pixel (high-potential region) indicating information is determined by four cells.

The resolution of the reference line discrimination scale means 8A is appropriately selected based on the size of the two-dimensional code imaged by the solid-state imaging means 3. Then, in the step shown in FIG. 11A, the decoder 4 converts the reference line discrimination scale means 8A into a line formed by the cells ce,..., Ce arranged in the matrix of the reference line discrimination scale means 8A. , Until a predetermined number of predetermined cells continuously appear as black cells.

Also in this example, the X-axis reference line Lx can be specified by about 28 cells in one line formed by the cells ce,..., Ce of the reference line discrimination scale means 8A. About 28 units per cell ce of the reference line determination scale means 8A.
The reference line discrimination scale means 8A is rotated until the black cells are aligned on one line.

FIG. 17 schematically shows a state in which about 28 black cells are arranged on one line for each cell ce of the reference line determination scale means 8A. In this example, the rotation operation of the reference line determination scale means 8A is stopped in a state where about 28 black cells are arranged on one line in units of cell ce of the reference line determination scale means 8A. However, the predetermined number of cells in which black cells are arranged in one line per cell ce of the reference line determination scale means 8A, which is a determination to stop the rotation operation of the reference line determination scale means 8A, is solid. The selection is appropriately made based on the size of the two-dimensional code captured by the imaging unit 3.

The decoder 4 has a predetermined number of black cells of 1 per cell ce of the reference line discrimination scale means 8A.
When aligned on the line, the rotation of the reference line discrimination scale means 8A is stopped, and a line ny in which a predetermined number of black cells are arranged on one line per cell ce of the reference line discrimination scale means 8A is converted to an X-axis reference line. L
x.

Next, after estimating the X-axis reference line Lx in this way, in the step shown in FIG. 11B, the decoder 4 has a predetermined angle with respect to the estimated X-axis reference line Lx. An operation of superposing a plurality of lines is performed, and a line in which a predetermined number of black cells continuously appear along a line having a predetermined angle is referred to as a Y-axis reference line L.
Specify y.

Then, the estimated X-axis reference line Lx of the image information temporarily stored in the image memory of the storage unit of the decoder 4 is set at the intersection between the estimated X-axis reference line Lx and the specified Y-axis reference line Ly. The angle θ between Lx and the specified Y-axis reference line Ly is corrected such that tan θ = ∞.

Next, the decoder 4 sums the number of black cells for each of several rows above and below the estimated X-axis reference line Lx (line ny in this example) in units of rows. Again, for ease of explanation, line n
An example in which the number of black cells is summed for each of four rows above and below y with respect to y will be described.

Also in this example, as shown in FIG. 18, there are a total of 28 black cells in the ny-th row, one black cell in the ny-l row, and a ny-2 row. Has a total of one black cell, a total of 0 black cells in the ny-3th row, and a total of 0 black cells in the ny-4th row. In the ny + 1th row, the total number of black cells is 28.
(Corresponding to the number of cells of the X-axis reference line Lx)
In the ny + 2th row, a total of 14 black cells (the number of cells of the Y-axis reference line Ly and the timing mark Tx
And the ny + 3 line has a total of 14 black cells (corresponding to the sum of the number of cells of the Y-axis reference line Ly and the number of cells of the timing mark Tx). , Ny + 4th row shows an example in which there are 14 black cells (corresponding to the sum of the number of cells of the Y-axis reference line Ly and the number of cells indicating information).

Here, the two-dimensional code cp is composed of an X-axis reference line Lx, a Y-axis reference line Ly, timing marks Tx,.
, Ty, black pixels serving as information, and auxiliary marks Mc, are sandwiched between the X-axis reference line Lx and the Y-axis reference line Ly, and on the side where the auxiliary marks Mc are provided. There is always a predetermined number or more of black cells in the area.

Therefore, if the minimum number of black cells existing for each row passing through the area of the code cp is set as the threshold value Yth, the estimated reference line ny estimated to be the X-axis reference line Lx is set at the center. A predetermined number of lines on one side of the periphery and a predetermined number of lines on the other side are scanned, and the number of black cells for each of the plurality of lines on one side and the plurality of lines on the other side is sent to the reference line determination scale means. The total number of black cells is determined in one of a predetermined number of lines on one side around the estimated reference line ny and a predetermined number of lines on the other side around the estimated reference line ny. If the number of black cells is equal to or greater than (the number of black cells / row ≧ threshold Yth) and the number of black cells is less than the predetermined number (the number of black cells / row <threshold Yth) on the other side, the estimation is performed. The reference line ny may determine the X-axis reference line Lx.

For easy understanding, this will be specifically described based on an example shown in FIG. Also in the example shown in FIG. 18, since the Y-axis reference line Ly is identified by two columns, two or more black cells always exist in the area of the two-dimensional code cp. Therefore, for each row passing through the area of the code cp, the threshold value Yt
If h is 2 (Yth = 2), the estimated reference line ny estimated to be the X-axis reference line Lx
, And a predetermined number of lines on the other side (in this example, ny-1 row, ny-2 row, ny-3 row, and n
y-4 rows) and a predetermined number of lines on one side (in this example, n
When scanning is performed for each of the y + 1 row, the ny + 2 row, the ny + 3 row, and the ny + 4 row, in this example, a plurality of lines (ny-1, row ny-2, ny-3, and ny−) on the other side are obtained.
4), the number of black cells in each line is equal to the threshold Y
less than th (in this example, Yth <2).

Further, a plurality of lines (ny + 1) on one side
Row, ny + 2 row, ny + 3 row, and ny + 4 row), a plurality of lines (ny + 1 row,
Since the number of black cells in each of the ny + 2 rows, the ny + 3 rows, and the ny + 4 rows) is equal to or greater than the threshold Yth (in this example, black cells / row ≧ 2), the number of black cells is the X-axis reference line Lx. Can be determined as the X-axis reference line Lx.

Next, in the step shown in FIG. 11 (c), the decoder 4 has the other side where the number of black cells is less than the predetermined number (in this example, it exists on each of the ny-1 and ny-2 rows). Each of the black cells cb and cb) is determined to be dirty, and FIG.
In the step shown in FIG. 1 (d), each of the black cells cb, cb determined to be dirty is converted into a white cell, and an image information correcting step of correcting image information developed in the image memory of the decoder 4 is performed. Based on the image information corrected in the image information correction step, the two-dimensional code information recorded in the area sandwiched between the X-axis reference line Lx and the Y-axis reference line Ly is, for example, JI
Decode to S code.

As described above, the decoder 4 outputs 2
The information decoded from the dimensional code information is sent to the arithmetic processing means 2
, And based on information decoded from the two-dimensional code information by the operation program stored in advance in the storage unit of the arithmetic processing means 2, the containers V,.
V is sorted. In this two-dimensional code reading method,
As is clear from the comparison between FIG. 9 and FIG. 18, as a pre-processing step of the reference line estimation step, an area Ra estimated to contain the two-dimensional code cp from image information captured by the solid-state imaging unit 3 is obtained. The two-dimensional code cp is read out from the cut out small information by a reference line estimation step, an image information correction step, and a decoding step, so that the amount of data used for decoding is reduced. Therefore, the two-dimensional code cp can be decoded at high speed.

In the image information extracting step, 2
Region Ra estimated to contain dimensional code cp
Is obtained by summing the number of black pixels for each row of the image information developed in the image memory of the storage unit of the decoder 4 for each photoelectric conversion element arranged in a matrix of the solid-state imaging means 3. From the first row nys and the last row nye of the rows including the predetermined number or more, a row nyc which is the center line of the area including the predetermined number or more of the black pixel information is determined, and The image information developed in the memory is transferred to the solid-state imaging unit 3.
For each photoelectric conversion element arranged in a matrix of
The number of black pixels is totaled, and a column nxc which is a center line of a region including a predetermined number or more of black pixel information is determined from a first column nxs and a last column nxe of columns including a predetermined number or more of black pixels. An area Ra slightly larger than the area of the two-dimensional code cp to be read in advance is determined from the image information developed in the image memory around the intersection cg1 of the row nyc serving as the center line and the column nxc serving as the center line. Since the clipping is performed, the two-dimensional code cp is included in the clipped region Ra with a high probability. Thereby, the cut-out region Ra
Inconveniences such as not including the two-dimensional code cp or only a part thereof are unlikely to occur.

In the above description, an example in which a black two-dimensional code is provided on a white background has been described. However, when a white two-dimensional code is provided on a black background, black cells and black pixels are provided. By inverting the relationship between the white cell and the white pixel in black and white, even if there is a stain near the two-dimensional code, it becomes possible to read it.

[0075]

As described in detail above, claim 1 is as follows.
According to the two-dimensional code reading method described in the above, for example, when a two-dimensional code is represented in black on a white background, a reference line is estimated in a reference line estimation step, and further the estimation estimated in this step is performed. Each of a predetermined number of lines on one side and a predetermined number of lines on the other side is scanned with the reference line as a center, and the predetermined number of lines on one side and the predetermined number on the other side are scanned as described above. The number of black cells for each of the lines
A predetermined number of lines on one side of the estimated reference line are equal to or more than a predetermined number, and the black cells are included in a predetermined number of lines on the other side. A reference line determining step is provided for determining the estimated reference line as the X-axis reference line or the Y-axis reference line when the number does not exceed the predetermined number.

Thus, even if the stain adheres to the area of the all white line provided along the opposite side of the X-axis reference line from the side where the timing mark is provided, the X-axis reference line is specified. can do. Similarly, the Y-axis reference line is specified even if the stain adheres to the area of the all white line provided along the side opposite to the side on which the timing mark is provided of the Y-axis reference line. be able to.

Thus, even if dirt exists near the two-dimensional code to be read, no two-dimensional code reading error occurs. Conversely, when a two-dimensional code is represented in white on a black background, a reference line is estimated in a reference line estimation step.
With the estimated reference line estimated in this step as a center, each of a predetermined number of lines on one side and a predetermined number of lines on the other side is scanned, and a predetermined number of lines on one side are scanned as described above. For each of the line and the predetermined number of lines on the other side, the number of white cells is totaled for each cell provided in the reference line determination means, and a predetermined number of lines on either side of the estimated reference line is calculated.
A reference line determination for determining an estimated reference line as an X-axis reference line or a Y-axis reference line when the number of white cells is equal to or more than a predetermined number and the number of white cells is not equal to or more than the predetermined number of lines on the other side. Steps are provided.

Thus, even if dirt adheres to the area of the black line provided along the opposite side of the X-axis reference line on which the timing mark is provided, the X-axis reference line is specified. can do. Similarly, the Y-axis reference line is specified even if the stain adheres to the area of the all black line provided along the side opposite to the side where the timing mark is provided on the Y-axis reference line. be able to.

Thus, even if dirt exists near the two-dimensional code to be read, no two-dimensional code reading error occurs. In the two-dimensional code reading method according to the second aspect, the X-axis reference line or the Y-axis reference line is specified by the same method as the two-dimensional code reading method according to the first aspect. Similar to the method of reading a two-dimensional code according to claim 1, when the two-dimensional code is represented in black on a white background, the two-dimensional code is normally located on the side opposite to the side where the timing mark of the X-axis reference line is provided. , Even if the area that must be an all-white line contains black pixel information due to dirt or the like,
A two-dimensional code can be read, and similarly, a black pixel caused by dirt or the like is located in an area on the opposite side to the side where the timing mark of the Y-axis reference line is provided, which should be an all white line. Even if the information is included,
Two-dimensional codes can be read.

When a two-dimensional code is represented in white on a black background, it must be an all black line on the opposite side of the X-axis reference line on which the timing mark is provided, for example. Even if the area includes white pixel information due to dirt or the like, the two-dimensional code can be read, and similarly, the entire area on the side opposite to the side on which the timing mark of the Y-axis reference line is provided, The two-dimensional code can be read even if the area that must be a black line contains white pixel information due to dirt or the like.

Further, in this two-dimensional code reading method,
As a preprocessing step of the reference line estimation step, a region estimated to contain a two-dimensional code is cut out from image information taken by the solid-state imaging means, and a two-dimensional code is read from this cut-out little information. Therefore, the two-dimensional code can be decoded at high speed by the amount of data used for decoding is reduced.

In the image information extracting step, 2
The area estimated to contain the dimensional code is obtained by converting the image information expanded in the image memory into photoelectric conversion elements arranged in a matrix of the solid-state imaging means, and for each row, the number of black pixels or white pixels. In total, the first row of the row in which the number of black pixels or white pixels is equal to or more than a predetermined number, and the last row, the row serving as the center line of the area including the predetermined number of black pixel information or white pixel information is determined. The image information expanded and stored in the image memory is determined for each photoelectric conversion element arranged in a matrix of solid-state imaging means, and for each column, the number of black pixels or white pixels is summed, and the number of black pixels or white pixels is calculated. The first column of the column that contains a predetermined number or more, and from the last column, determine the column that is the center line of the region that includes the predetermined number or more of black pixel information or white pixel information, and a row that becomes the center line, Image information developed in the image memory, centered on the intersection of the column serving as the center line Et al, so that cut out slightly larger area than the area of the two-dimensional code to be read in advance.

As a result, since the two-dimensional code is included in the cut-out area with a high probability, the two-dimensional code is not included in the cut-out area, or only a part thereof is included. It is unlikely that such inconveniences occur.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram schematically illustrating a two-dimensional code reader that implements a two-dimensional code reading method according to the present invention.

FIG. 2 is an enlarged perspective view schematically showing one of containers sorted by the two-dimensional code reader shown in FIG. 1;

FIG. 3 is a processing procedure diagram schematically illustrating an example of a two-dimensional code reading operation performed by an arithmetic processing unit and a decoder of the two-dimensional code reading device illustrated in FIG. 1;

FIG. 4 is a processing procedure diagram schematically showing an example of a two-dimensional code reading operation performed by the arithmetic processing means and the decoder of the two-dimensional code reading device shown in FIG. 1;

FIG. 5 is a diagram schematically illustrating image information captured by a solid-state imaging unit.

FIG. 6 is a diagram schematically showing reference line discrimination scale means, which is used in the decoder of the two-dimensional code reader according to the present invention and is electrically created, in which a plurality of cells are arranged in a matrix.

FIG. 7 is a reference line discrimination scale means in which a plurality of cells are arranged in a matrix and electrically created in image information temporarily stored in a storage unit of a decoder used in the two-dimensional code reader according to the present invention. It is a figure which shows typically the state which superimposed.

FIG. 8 is a diagram schematically showing a state in which black cells are arranged on one line in cell units of the reference line discrimination scale means.

FIG. 9 is an explanatory diagram schematically illustrating a step of determining an estimated reference line as an X-axis reference line or a Y-axis reference line.

FIG. 10 is a processing procedure diagram schematically showing another example of the two-dimensional code reading operation performed by the arithmetic processing means and the decoder of the two-dimensional code reading device shown in FIG. 1;

11 is a processing procedure diagram schematically showing another example of the two-dimensional code reading operation performed by the arithmetic processing means and the decoder of the two-dimensional code reading device shown in FIG. 1;

FIG. 12 is a diagram schematically illustrating an image information extracting step.

FIG. 13 is a diagram schematically illustrating an image clipping unit configured to cut out a region slightly larger than a region of a two-dimensional code, configured by an electrical unit.

FIG. 14 is a diagram schematically showing a state in which an area that will include a two-dimensional code is cut out by an image cutting unit.

FIG. 15 schematically illustrates an electrically created reference line discrimination scale means having a plurality of cells arranged in a matrix having a size sufficient to analyze a region that will contain a two-dimensional code. FIG.

FIG. 16 is a diagram schematically illustrating a state in which a reference line discrimination scale unit is superimposed on an area that will include a two-dimensional code.

FIG. 17 is a diagram schematically showing a state in which black cells are arranged on one line for each cell of the reference line determination scale means.

FIG. 18 is an explanatory diagram schematically illustrating a step of determining an estimated reference line as an X-axis reference line or a Y-axis reference line.

FIG. 19 is an explanatory diagram schematically showing a configuration of a matrix type code (two-dimensional matrix code) as an example of a two-dimensional code.

FIG. 20 is an explanatory diagram schematically showing an example of a two-dimensional code to which dirt to be treated as a reading error is attached.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 2D code reader 2 Arithmetic processing means 3 Solid-state imaging means 4 Decoder 6 Transport means 7 Container detection means 7a Infrared light emitting element 7b Infrared light receiving element 8, 8A Reference line discrimination scale means 9, 9A It has a line which has a predetermined angle. Data cp Two-dimensional code Lx X-axis reference line Ly Y-axis reference line Mc Auxiliary mark Tx, Ty Timing mark cb Black cell due to dirt Sp Dirt

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ryo Dayta 43-1 Takehara, Nagaizumi-cho, Sunto-gun, Shizuoka Prefecture 402 Diamond Palace Takehara 402 (72) Inventor Hirokazu Yoshida 4-36-32, Senriyamanishi, Suita-shi, Osaka-shi (72 ) Inventor Susumu Okura 2-82-21-107 Fuku term (reference) 2-chome Yakumo Higashicho, Moriguchi City, Osaka 5B072 AA01 AA02 BB04 BB06 BB10 CC13 CC17 CC21 DD15 DD22 EE12

Claims (2)

[Claims] An X-axis reference line and a Y-axis reference line are provided in an L-shape, and predetermined information is stored in a region sandwiched between the X-axis reference line and the Y-axis reference line by a two-dimensional code. A method of reading a two-dimensional code recorded in an encrypted form, comprising: an image capturing step of capturing an image of a predetermined area including the two-dimensional code by a solid-state image capturing means; And a reference line discriminating scale means in which a plurality of cells are arranged in a matrix on the image information developed in the image memory. When a predetermined number of predetermined cells continuously appear as black cells on any of the lines, the reference The rotation of the in-determination scale means is stopped, and a line in which black cells or white cells appearing in any one of the lines of the reference line determination scale means are estimated to be either the X-axis reference line or the Y-axis reference line. A reference line estimating step, and a predetermined number of lines on one side and a predetermined number on the other side around the estimated reference line estimated to be either the X-axis reference line or the Y-axis reference line Scanning for each of the lines, the number of black cells or the number of white cells for each of the plurality of lines on the one side and the plurality of lines on the other side are summed for each cell provided in the reference line determination scale means, and the estimation is performed. A predetermined number of lines on one side around the reference line and the estimated reference line; If the number of black cells or white cells is greater than or equal to a predetermined number on one side of a predetermined number of lines on the other side around the other side, and the number of black or white cells is not greater than or equal to a predetermined number on the other side. A reference line determining step of determining the estimated reference line as an X-axis reference line or a Y-axis reference line. 2. An X-axis reference line and a Y-axis reference line are provided in an L-shape, and predetermined information is stored in a region sandwiched between the X-axis reference line and the Y-axis reference line by a two-dimensional code. A method for reading a two-dimensional code that has been converted and recorded, wherein: an imaging step of imaging a predetermined area including the two-dimensional code by solid-state imaging means in which a plurality of photoelectric conversion elements are arranged in a matrix; A developing step of developing image information captured by the image capturing means into an image memory; and a black pixel for each row unit for each photoelectric conversion element arranged in a matrix of the solid-state image capturing means for the image information developed for the image memory. The number of black pixels or the number of white pixels is summed, and from the first row and the last row of the row in which the number of black pixels or white pixels is equal to or more than a predetermined number, an area including a predetermined number or more of black pixel information is determined. Determine the row that will be the core wire, the image information developed in the image memory in photoelectric conversion element units arranged in a matrix of solid-state imaging means, for each column unit, the total number of black pixels or white pixels, From the first column and the last column of the column in which the number of black pixels or the number of white pixels are included in a predetermined number or more, determine a column to be the center line of an area including the predetermined number or more of black pixel information or white pixel information, An image information extracting step of extracting an area slightly larger than an area of a two-dimensional code to be read in advance from the image information developed in the image memory around an intersection of a row serving as a center line and a column serving as a center line. And, after superimposing reference line discrimination scale means in which a plurality of cells are arranged in a matrix on the image information cut out in the image information cutting step, rotate the reference line discrimination scale. At a point where a predetermined number of predetermined cells continuously appear as black cells or white cells on any of the lines of the row, the rotation of the reference line determination scale means is stopped, and any of the reference line determination scale means is stopped. A reference line estimating step of estimating that a line in which black cells or white cells appearing in the line are continuous is either the X-axis reference line or the Y-axis reference line; Scanning each of a predetermined number of lines on one side and a predetermined number of lines on the other side around the estimated reference line estimated to be any one of the plurality of lines on the one side and the other side The number of black cells or the number of white cells for each of the The number of black cells or the number of white cells are added to one of a predetermined number of lines on one side around the estimated reference line and a predetermined number of lines on the other side around the estimated reference line. A reference line determining step of determining the estimated reference line as an X-axis reference line or a Y-axis reference line when the number of cells is equal to or more than a predetermined number and the number of black cells or white cells is not equal to or more than the predetermined number on the other side; A method for reading a two-dimensional code, comprising: