JP2000268122A - Two-dimensional code reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To read a two-dimensional code present at a specified position in the case that the two-dimensional codes are crowded in a narrow area. SOLUTION: This reader is provided with an image sensor 11 for reading the two-dimensional code, an image memory 13 for storing the image data of the two-dimensional code read by the image sensor 11, a judgment means 14 for judging whether or not the image data of the two-dimensional code are present in a specified read range in the image data stored in the image memory 13 and a decoding means 14 for decoding the data in the case of judging that the image data of the two-dimensional code are present inside the specified read range by the judgment means 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-dimensional code reader for reading a two-dimensional code.

[0002]

2. Description of the Related Art Since a two-dimensional code has a larger amount of information than a bar code, it is frequently used when one code needs to store a large amount of information. Such a two-dimensional code is read by, for example, a handy type two-dimensional code reader.

The two-dimensional code read by the two-dimensional code reader is stored in an image memory, decoded, and output.

[0004] When a large number of two-dimensional codes are densely packed in a narrow area, there is a problem that it is difficult to know which two-dimensional code is read.

[0005] This situation will be described with reference to FIG. FIG.
, 1 is an input image read into an image memory by a two-dimensional barcode reader. The input image 1 includes nine two-dimensional codes 2.

As described above, when a plurality of two-dimensional codes 2 exist in the input image 1, the reading process is to read all the symbols or one of the symbols.

In the reading process, in the case of reading one of the symbols, there is a problem that it is impossible to know which symbol the read symbol is.

If the symbols are arranged so that a plurality of symbols are not included in one image, the above-mentioned problem is eliminated. However, if the space for arranging the symbols is limited, the interval between the symbols becomes narrow. In many cases, one image includes a plurality of symbols.

Also, by changing the resolution of the reading device to match the size of the symbol and the size of the captured image to an appropriate size, a plurality of symbols can be prevented from being included in one image. .

However, this method requires a hardware change, which is disadvantageous in terms of cost.

[0011]

Next, FIG. 10 and FIG.
The two-dimensional code reading process will be described with reference to FIG. As shown in FIG. 8, an input image 1 includes nine two-dimensional codes 2. Then, there are five scan lines for detecting the position of the two-dimensional code 2. These five scan lines are labeled 3a to 3e.

Then, in order to detect the position of the two-dimensional code 2, scanning is performed from end to end on the scan lines 3a to 3e, and it is determined whether or not the outline of the two-dimensional code 2 exists on the scan lines 3a to 3e. Searching.

In the case of FIG. 10, all the outlines of the nine two-dimensional codes 2 as the input image 1 are the scan lines 3a.
3e, all the two-dimensional codes 2 or any one of the two-dimensional codes 2 at an undefined position
Is detected.

Next, a process of reading a two-dimensional code from the input image 1 of FIG. 10 will be described with reference to a flowchart of FIG.

First, the Y coordinates of the scan lines 3a to 3e are determined (step S1). Then, a scan is performed on one of the determined scan lines 3a to 3e (step S2).

Then, while scanning the determined scan line, it is detected whether or not there is an outline of the two-dimensional code 2 (step S3).

If "YES" is determined in step S3, that is, if it is determined that the outline of the two-dimensional code 2 has been found, the two-dimensional code 2 is cut out (step S4).

Then, decoding processing of the extracted two-dimensional code is performed (step S5).

It is determined whether the result of the decoding in step S5 is successful (step S6).

If the determination in step S6 is "YES", that is, if it is determined that decoding has been successful, the decoding process ends at that point.

If the determination in step S6 is "NO", the process returns to step S3.

If "NO" is determined in step S3, it is determined whether the scan of the scan line determined in step S1 has been completed (step S3).
7).

If the determination in step S7 is "NO", the processing from step S3 is repeated.

By the way, in the determination of step S7, "YE
S ”, all scan lines 3a
It is determined whether all of the scans to 3e have been completed (step S8).

If the determination in step S8 is "NO", the next scan line among the scan lines 3a to 3e is determined in step S1 described above.

Then, all the scan lines 3a to 3e
When the scan for is completed, all the processing ends.

In such a two-dimensional code reading method,
If the decoding process is successful, the reading process is terminated, so that the result of the first detected two-dimensional code is output.

For this reason, when a plurality of two-dimensional codes exist on a scan line, there is a problem that it is not known which two-dimensional code has been decoded.

The present invention has been made in view of the above points, and has as its object to provide a two-dimensional code capable of reading a two-dimensional code at a specific position when two-dimensional codes are densely packed in a narrow area. To provide a reader.

[0030]

A two-dimensional code reader according to claim 1 comprises: reading means for reading a two-dimensional code;
An image memory for storing the image data of the two-dimensional code read by the reading means, and determining whether the image data of the two-dimensional code exists in a specific reading range among the image data stored in the image memory. Determining means;
When the determination means determines that the image data of the two-dimensional code exists within the specific reading range, the image processing apparatus further comprises decoding means for decoding the image data.

A two-dimensional code reader according to a second aspect is characterized in that the specific reading range according to the first aspect can be changed.

In the two-dimensional code reader according to the present invention, when the determination means determines that the image data of the two-dimensional code does not exist in a specific reading range among the image data stored in the image memory, , And the subsequent reading process is terminated.

According to a fourth aspect of the present invention, there is provided a two-dimensional code reader, comprising: means for designating the number and length of the scan lines according to the first aspect, wherein the specific reading range is designated by the designating means. It is characterized by.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a two-dimensional code reader. In FIG. 1, reference numeral 1 denotes a two-dimensional code reader. The two-dimensional code reader 1 has a main body 1a and a grip 1b.

A reading port 2 is provided on the front surface of the main body 1a. An image sensor 1 is provided inside the reading opening 2.
The circuit shown in the block diagram of FIG.

A communication cable 3 connected to the communication interface shown in FIG. 2 is connected to the lower end of the grip 1b. The communication cable 3 is connected to a host computer (not shown).

The trigger switch 4 is provided on the grip 1b. The reading operation is started by operating the trigger switch 4.

Next, the system configuration of the two-dimensional code reader will be described with reference to FIG. In FIG. 2, 1
0 is a CPU that controls and controls the two-dimensional code reader
(Central processing unit). The system bus 10a from the CPU 10 includes a DMA (direct memory access) 12, an image memory 13, a ROM (read only memory) 14, an I / O port 15, a communication interface 16, and a RAM (random access memory). Memory) 17,
An input unit (designating means) 18 is connected.

The input section 18 has a function of inputting the number of scan lines and the length of the read range. Also,
The ROM 14 stores a program shown in the flowchart of FIG.

The image sensor 11 is connected to the DMA 12. The image sensor 11 is, for example, a CCD.
It is composed of an area sensor. The image data of the two-dimensional code imaged by the image sensor 11 is DMA
The image data is transferred to the image memory 13 by DMA.

The I / O port 15 is connected to the trigger switch 4 described with reference to FIG.

Next, the first embodiment of the present invention configured as described above will be described. First, when the two-dimensional code is read by the two-dimensional code reader 1, the image data of the two-dimensional code read by the
The image data is stored in the image memory 13 under the control of S12. The state of the image data of the two-dimensional code stored in the image memory 13 is shown in FIG.

Hereinafter, description will be given with reference to the flowchart of FIG. In this embodiment, the scan lines are limited to the positions shown in FIG. That is, the scan lines have the same Y coordinate as shown by SL1 and SL2, and are arranged so as to be separated by a predetermined interval. This means that only the central two-dimensional code of the two-dimensional code image data stored in the image memory 13 is to be read.

First, Y of the scan lines SL1 and SL2
The coordinates are determined (step S11).

The determination of the Y coordinate is performed by the input unit 18.

As described above, the scan lines SL1 and SL2
Is determined, the specific reading range can be changed.

Then, scanning is started (step S12).

Then, it is determined whether the scan has reached the scan target position (step S13). This step S1
In the determination of 3, the scan is performed on the scan lines SL1 and SL2.
Is determined, it is determined whether the outline of the two-dimensional code has been found (determination means) (step S14). It is determined whether the outline of the two-dimensional code, that is, what is likely to be a two-dimensional code is found.

If "YES" is determined in step S14, a two-dimensional code cutout process is performed (step S15).

Further, decoding processing of the extracted two-dimensional code is performed (decoding means) (step S1).
6).

Then, it is determined whether the decoding process performed in step S16 is successful (step S1).
7).

If "NO" is determined in the determination in step S17, the processes in step S13 and thereafter are repeatedly performed.

By the way, in the determination of step S17, "YE
If it is determined to be "S", a series of processing ends.

By the way, in the determination of step S14, "N
If it is determined to be "O", it is determined whether the line scan has been completed (step S15).

If the determination in step S15 is "YES", a series of processing ends.

That is, when it is determined that there is no two-dimensional code in the specific reading range, the reading process is terminated, so that it is possible to prevent the reading process from being unnecessarily lengthened.

On the other hand, if "NO" is determined in the determination in step S15, the processing in step S13 and thereafter is performed.

Next, a second embodiment of the present invention will be described with reference to FIGS. In the first embodiment described above, the number of scan lines is one. However, a plurality of scan lines may be set as in the second embodiment.

First, as shown in FIG.
Are set at the top and bottom with respect to the scan line SL11 at the center of the visual field.

The number of scan lines to be used can be set from the input unit 18.

For example, when the number of scan lines “3” is input from the input unit 18, three scan lines SL11 to SL13 are selected as shown in FIG.

Then, the scan lines SL11 to SL1
3, the setting of an area to be scanned in the X direction is also set by the input unit 18. Specifically, a start point and an end point for scanning in the X direction are set.

In this manner, a specific reading range can be specified by the number and length of the scan lines. Since the two-dimensional code within the designated reading range is read, the user can select and read the two-dimensional code desired to be read. For example, taking the scan line SL11 as an example, a region to be scanned in the Y direction will be described. On the scan line SL11, two scan areas SL11a and SL11b are provided. Thus, the two scan areas SL11
By providing a and SL11b, one of the two scan areas SL11a and SL11b can be made to cover the two-dimensional code.

For example, as shown in FIG. 8, when the number of horizontal pixels in the visual field is "100", and the user sets the code size to "40" and the allowable range to "10", When the code is arranged at the correct center position, the outline of the code exists at the position of 30 dots and the position of 70 dots. An allowable range of “10” means that between 25 dots and 35 dots from the left and 6 dots on the right.
What is necessary is just to set the scan area between 5 dots and 75 dots.

By doing in this way, the outline of the code in the right scan area is always a transition point (edge point) from white to black, and the outline of the code in the left scan area is always black to white. Since the feature that is the transition point (edge point) is used, the transition point (edge point) with the reverse attribute is not detected.

In the above-described embodiment, when a two-dimensional code is read, even if the two-dimensional code is densely packed in a narrow area, the code to be read is not limited to the two-dimensional code but may be another two-dimensional code. There may be.

[0067]

According to the present invention, when two-dimensional codes are densely packed in a narrow area,
A two-dimensional code at a specific position can be read.

[Brief description of the drawings]

FIG. 1 is a perspective view of a two-dimensional code reader according to first and second embodiments of the present invention.

FIG. 2 is a system configuration diagram of a two-dimensional code reader according to the embodiment;

FIG. 3 is a view showing a two-dimensional code stored in an image memory according to the embodiment;

FIG. 4 is a flowchart for explaining the operation of the first embodiment.

FIG. 5 is a diagram showing scan line positions in an image memory according to a second embodiment of the present invention.

FIG. 6 is a view showing a selected scan line among scan lines in an image memory according to the second embodiment.

FIG. 7 is a view for explaining the length of a scan line according to the second embodiment.

FIG. 8 is a diagram showing a positional relationship between scan lines and image data according to the second embodiment.

FIG. 9 is a diagram showing an example of a two-dimensional code stored in a conventional image memory.

FIG. 10 is a view showing a relationship between a two-dimensional code stored in a conventional image memory and a scan line.

FIG. 11 is a flowchart for explaining a conventional two-dimensional code reading process.

[Explanation of symbols]

 10 CPU, 11 image sensor, 12 DMA, 13 image memory, 14 ROM, 15 I / O port, 16 communication interface, 17 RAM, 18 input unit.

Claims (4)

[Claims] 1. A reading means for reading a two-dimensional code, an image memory for storing image data of the two-dimensional code read by the reading means, and a specific reading range of image data stored in the image memory Determining means for determining whether or not image data of a two-dimensional code exists in the image data. If the determination means determines that image data of the two-dimensional code exists within the specific reading range, the image data is decoded. A two-dimensional code reader, comprising: 2. The two-dimensional code reader according to claim 1, wherein the specific reading range is changeable. 3. When the determination means determines that the image data of the two-dimensional code does not exist in a specific reading range among the image data stored in the image memory, the subsequent reading processing is ended. The two-dimensional code reader according to claim 1, wherein: 4. The two-dimensional code reader according to claim 1, further comprising designating means for designating the number and length of the scan lines, wherein the designating means designates the specific reading range. .