JPH09128469A - Two-dimensional code verification device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To verify whether a two-dimensional code such as a matrix code is correctly printed or not to a print medium. SOLUTION: Each reference item is provided with a reference item area 14-1 storing data of a reference item to verify and judging numerical data in the reference item. Then, with respect to a two-dimensional picture read by a two-dimensional code scanner 1, an evaluating numerical value is calculated concerning each reference item stored in the reference item area 14-1 to execute synthetic judgement based on this evaluating numerial value.

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 verification device for verifying whether a two-dimensional code printed on a print medium is printed correctly.

[0002]

2. Description of the Related Art Two-dimensional codes such as various bar codes, multi-step bar codes and matrix codes shown in FIG. 9 are used in industries such as distribution. By the way, in most cases, these codes are automatically read by a reading device such as a scanner to decode the information that the code means, and various processes such as settlement and inventory management are performed based on this information.

By the way, various bar codes and two-dimensional codes are usually printed on a label or the like by a printer or the like, and the printing quality thereof varies depending on the performance of each printer. However, when the print quality is extremely poor, a reading error occurs when reading the code with the above reading device,
There is a problem that various operations such as settlement and inventory management are delayed.

Therefore, conventionally, regarding various barcodes, there is a barcode verifier that verifies whether or not the printed barcode is correctly printed. This bar code verifier is to check whether the bar code conforms to a predetermined specification (standard) .For example, the bar code composing the bar code can be inspected for variations in thickness, and the variations can be allowed. If it is within the range, it is judged as conforming, and if it exceeds the allowable range, it is judged as non-conforming, and it is displayed by a display device such as a display. Even in the case of a two-dimensional code, in particular, the multi-stage bar code has a structure in which the bar codes are vertically stacked. Therefore, in principle, the multi-stage bar code can be correctly printed by a verification device almost similar to the above bar code detector. Can be verified.

[0005]

However, a two-dimensional code such as a matrix code excluding a multi-stage bar code cannot be simply verified from the variation in the bar thickness, unlike a bar code verifier. , Those two
An apparatus for verifying whether the two-dimensional code is printed correctly has not been generally developed, and it has not been possible to verify whether the two-dimensional code is printed correctly.

Therefore, an object of the present invention is to provide a two-dimensional code verification device which verifies whether various two-dimensional codes such as a matrix code are correctly printed on a print medium.

[0007]

The invention corresponding to claim 1 is:
Reading means for reading the image of the two-dimensional code printed on the print medium, reference item setting means for setting reference items to be verified with respect to the two-dimensional code image read by the reading means, and the reference item. An evaluation unit that sequentially evaluates the two-dimensional code image based on the reference item set by the setting unit, and a verification unit that verifies whether the printing state of the two-dimensional code on the print medium is correct based on the evaluation result by the evaluation unit. Is provided.

The invention according to claim 2 is the invention according to claim 1, wherein the reference item set by the reference item setting means includes a variation in the size of the basic pattern forming the two-dimensional code.

According to a third aspect of the present invention, in the first aspect of the invention, the reference item set by the reference item setting means includes distortion in the vertical and horizontal directions of the two-dimensional code.

According to a fourth aspect of the present invention, in the first aspect of the invention, the reading means corrects a reading error in a basic pattern unit forming a two-dimensional code for a read image of the two-dimensional code. The reference item set by the reference item setting means includes the number corrected by the error correction function when the two-dimensional code is read by the reading means.

According to a fifth aspect of the invention, in the first aspect of the invention, the reference item set by the reference item setting means includes a contrast in printing / non-printing of the basic pattern forming the two-dimensional code. .

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a second embodiment of the present invention.
It is a figure which shows the whole structure of a dimension code verification apparatus. As an example of this embodiment, a two-dimensional code verification device provided with software for verifying a matrix code will be described here.

Reference numeral 1 denotes a two-dimensional code scanner as a reading means for reading an image of a two-dimensional code such as a matrix code printed on a print medium. The two-dimensional code scanner 1 has a function of correcting an error in reading one module at the time of reading, and transmits the image data on which this error correction is performed to the host computer 3 via the cable 2.

FIG. 2 is a block diagram showing a circuit configuration of a main part of the host computer 3. Reference numeral 11 denotes a CPU (central processing unit) constituting the control unit body.
A ROM (read only memory) 12 in which program data for processing performed by the CPU 11 is stored, a RAM (random access memory) 13 in which areas of various memories used when the CPU 11 performs processing are formed, a hard disk device or a floppy disk device. I / O (input / output) connected to various peripheral devices such as memory unit 14
Each of the ports 15 is connected to the CPU 11 via a system bus 16.

The CPU 11 also controls a keyboard interface 18 for controlling data transmission with a keyboard 17 via the system bus 16, a display controller 20 for controlling a display device 19, the two-dimensional code scanner 1 and the cable 2. It is connected to the scanner interface 21 that controls data transmission via the.

The memory unit 14 stores the total number of reference items.
A reference item area 14-1 is formed as reference item setting means for storing the data of the reference item to be verified with respect to the matrix code and the judgment numerical value data for the reference item (here, n).

FIG. 3 is a diagram showing a flow of verification processing performed by the CPU 11 of the host computer 3. First, 1 is set in the storage area x formed in the RAM 13, and the storage area x is set as the processing of step 1 (ST1).
Based on the numerical value x set in, the reference item area 14-1
Read the x-th reference item data and the judgment numerical value data of the reference item. Next, the read two-dimensional code image is evaluated based on the x-th reference item data,
Calculate the evaluation value (evaluation method).

For example, as a first example of the standard items, each module (basic pattern
) 21 was read due to variation in width (length and width) of 2
Evaluate the dimension code image. One line of the matrix code shown in FIG. 4A has no variation in the width of each module 21. Further, in one line of the matrix code shown in FIG. 4B, the width W3 of the unprinted white module 21 which is the sixth from the left and the width B4 of the black module 21 which is the seventh printed from the left are different from each other. It is smaller than the module, and the width of each module 21 varies. As a method of calculating the evaluation numerical value, it is possible to express the numerical value by calculating the average value and the variance of the thickness.

In practice, white modules W1 to W
5 and the black modules B1 to B5 may have different widths due to the thick and thin modules generated due to printing problems. Therefore, by individually calculating the average value and variance of the module thicknesses of the white module and the black module, it is possible to represent the variation due to the thinness of the white and black modules as a numerical value. When the difference between the average values calculated individually from the white and black modules is obtained, this difference becomes a numerical value that quantitatively expresses the overweight and thinness of the white and black modules, and the matrix code evaluation based on the printing accuracy of the printer It will represent a numerical value.

As a second example of the reference item, the read two-dimensional code image is evaluated by the distortion of the matrix code. FIG. 5 is a diagram in which the structure of the matrix code is simplified geometrically, and the matrix code shown in FIG. 5 (a) has no distortion. In the matrix code shown in FIG. 5B, the entire matrix code (each module) is not a square quadrangle but a substantially parallelogram, and distortion occurs. As the calculation method of the evaluation value, the length of the outline of the whole matrix code (each module) and the angle at which the outline intersects are calculated (calculated)
By doing so, it can be expressed as a numerical value.

FIG. 6 is a diagram showing another example of the distortion of the matrix code. In this matrix code, the matrix code as a whole is a quadrilateral, but some or all of the modules of this matrix code are distorted. However, this is the first of the criteria items mentioned above.
As described in the above example, it can be evaluated by the variation in the width of each module.

As a third example of the reference item, the read two-dimensional code image is evaluated according to the number of modules in the two-dimensional code scanner 1 in which the error correction is performed.
For example, as shown in FIG. 7, the print-defective module 21 is not recognized as a black module by simple processing.
It is corrected as a black module by the error correction function of the two-dimensional code scanner. Therefore, evaluation is performed by the number of modules (black modules and white modules) corrected by this error correction function. That is, the reliability of the two-dimensional code image can be represented as an evaluation numerical value by this number.

As a fourth example of the reference item, the read two-dimensional image is obtained by the contrast between the part corresponding to the black module and the part corresponding to the white module in the signal waveform of the read image output from the two-dimensional code scanner 1. Evaluate the code image. FIG. 8 is a diagram showing one line of the matrix code and a waveform read by the two-dimensional code scanner 1 (in one scan) corresponding to the one line. First from the left
In the th black module (width b1), at the time point t1, the read level is automatically and properly adjusted.
For example, the black module (width b1 is changed) depending on the high frequency component and the low frequency component of the read waveform.
) Is recognized. Then at time t2,
It is recognized that when the read waveform exceeds the judgment level, it comes out of the black module and enters the white module (width W1).

Similarly, when the read waveform falls below the determination level, each white module (width W1 to W5,
It is recognized that each black module (widths B2 to B5, ...) Has exited and the read waveform exceeds the judgment level, and each black module (B2 to B5, ...) It is recognized that the white module (width W2 to W5) has been entered.

Therefore, in the black module portion of the read waveform, the overall level becomes lower by falling below the determination level, and in the white module portion of the read waveform, the overall level becomes higher by exceeding the determination level. . Therefore, contrast occurs between the black module portion and the white module portion of this read waveform.

For this contrast, the height (lowness) of each module portion is obtained from a preset level (level line) H, and the height between the black module portion and the white module portion of the read waveform ( It can be calculated as the difference of (). The calculated contrast can be expressed as an evaluation value indicating the reliability in identifying the black module and the white module, that is, the reliability of the read two-dimensional code image.

There are various other methods for evaluating the matrix code, and the reference items corresponding to these methods are set in order in the reference item area 14-1. Based on the xth reference item data called as described above, the read two-dimensional code image is evaluated,
When the evaluation numerical value is calculated, the evaluation numerical value is compared with the judgment numerical value data of the xth reference item to determine whether the read two-dimensional code image conforms to the Xth reference item. Here, if it is determined that the result is conforming, the data of the conformity and its evaluation numerical value are RA for the x-th criterion item.
Store (set) in a predetermined area of M13. When it is determined that the nonconformity is found, the nonconformity is stored in a predetermined area of the RAM 13.
( set.

Next, the addition / update processing of +1 is performed on the numerical value x set in the storage area x, and whether or not the numerical value x of the storage area x subjected to the additional update is larger than the total number n of reference items. To judge. Here, the numerical value x of the storage area x
When it is determined that the total number is less than or equal to n, the process returns to the above-mentioned step 1 again.

When it is judged that the numerical value x is larger than the total number n, the two-dimensional code read this time is determined based on the data of conformity / nonconformity and evaluation numerical values for each reference item stored in a predetermined area of the RAM 13. Comprehensively evaluate whether or not it is printed correctly (verification means). In addition,
In this comprehensive evaluation, for example, if even one of the reference items is evaluated as non-conforming, it may be evaluated that the two-dimensional code is not printed correctly, or, for example, a common negative value is calculated from the evaluation values. However, when the total of the negative values is less than the predetermined lower limit value, it may be evaluated that the two-dimensional code is not printed correctly.

When the comprehensive evaluation is completed, the evaluation result is displayed on the display unit 19 and the verification process is completed.

In the present embodiment having such a configuration, the reference item area 14-1 relates to all reference item data necessary for verifying a two-dimensional code such as a matrix code in advance and the reference item. Judgment numerical value data is stored. A two-dimensional code such as a matrix code to be verified is read by the two-dimensional code scanner 1 and transmitted to the host computer 3 as two-dimensional code image data (analog data before binarization).

The host computer 3 reads the reference item data and the judgment numerical data of the reference items in order from the reference item area 14-1 to the 1st to nth items. For example, as reference items, there are variations in the width of each module forming the matrix code, distortion of the matrix code, the number of modules for which error correction has been performed, a portion corresponding to a black module and a portion corresponding to a white module. There is a contrast of the read waveform of.

Every time the reference items are read in this way,
The read two-dimensional code image data is evaluated for each reference item to calculate an evaluation value. It is determined whether the read two-dimensional code image data conforms to the corresponding reference item based on the determination numerical value data for the calculated evaluation numerical value. When it is judged as conforming, the data of conformity and evaluation numerical values for the corresponding standard items are stored in RAM.
If it is set to 13, and if it is determined that it is non-conforming, the evaluation of non-conformity for the corresponding reference item is set in the RAM 13. As described above, the RAM 13 stores the evaluation results for each reference item, that is, the data of conformity and evaluation numerical values or the data of nonconformity in order. When the evaluation result for the last reference item is stored in the RAM 13, a comprehensive evaluation is performed, and the comprehensive evaluation causes the display 19 to display the evaluation result as to whether or not the two-dimensional code is correctly printed. .

As described above, according to this embodiment, the reference item area 1 in which the data of the reference item to be verified for each reference item and the numerical value data for determination in the reference item are stored.
4-1 is provided for the reference item area 14 for the matrix code image read by the two-dimensional code scanner 1.
It is possible to verify whether the matrix code (two-dimensional code) is printed correctly by calculating the evaluation value for each reference item stored in -1 and making a comprehensive judgment based on this evaluation value. it can.

Further, according to this embodiment, since the variation in the width of the module of the matrix code is evaluated, at least the same level of reliability as that for verifying the conventional bar code is secured. Then, the matrix code can be verified.

Further, according to this embodiment, the overall distortion of the matrix code (distortion in the vertical and horizontal directions is
) Is included, the necessary verification can be performed in the two-dimensional code. this is,
This is a point that conventional barcode verification cannot handle.

Further, according to this embodiment, since the evaluation of the number of modules in which the error correction is performed in the two-dimensional code scanner 1 is included,
The reliability of the image data of the read two-dimensional code can be evaluated, and the actually printed two-dimensional code can be verified more directly rather than from the read image data.

Further, according to this embodiment, the contrast of the portion corresponding to the black module and the portion corresponding to the white module in the signal waveform of the read image output from the two-dimensional code scanner 1 can be evaluated. Since it is included, the reliability in distinguishing between the black module and the white module can be verified.

It is possible to verify whether or not the two-dimensional code is correctly printed more accurately and highly accurately by evaluating each of the above criteria items and comprehensively evaluating the evaluation results. it can.

Although the present embodiment has been described with respect to the evaluation of all the above criteria items, the present invention is not limited to this, and some of them are selected and selected. It is also possible to evaluate the reference items, and then comprehensively evaluate and verify the results.

[0041]

As described in detail above, according to the present invention,
A two-dimensional code verification device for verifying whether a two-dimensional code such as a matrix code is correctly printed on a print medium can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of a two-dimensional code verification device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of a main part of a host computer of the two-dimensional code verification device according to the first embodiment.

FIG. 3 is a view showing a flow of verification processing performed by the host computer of the two-dimensional code verification device of the embodiment.

FIG. 4 is a diagram showing an example in which there is no variation in the width of each module in one line of a matrix code, and a certain example.

FIG. 5 is a simplified diagram showing an example in which there is no distortion in the geometric structure of the matrix code and one example.

FIG. 6 is a simplified diagram showing another example of distortion in the geometric structure of a matrix code.

FIG. 7 is a diagram showing an example of a print defect module in a matrix code.

FIG. 8 is a diagram showing one line of a matrix code and a waveform read by the two-dimensional code scanner in this one line.

FIG. 9 is a diagram showing an example of a matrix code.

[Explanation of symbols]

 1 ... Two-dimensional code scanner, 3 ... Host computer, 11 ... CPU, 14-1 ... Reference item area.

Claims (5)

[Claims] 1. A reading unit for reading an image of a two-dimensional code printed on a print medium, and a reference item setting unit for setting a reference item to be verified with respect to the two-dimensional code image read by the reading unit. And an evaluation unit that sequentially evaluates the two-dimensional code image based on the reference item set by the reference item setting unit, and a printing state of the two-dimensional code on the print medium based on the evaluation result by the evaluation unit. A two-dimensional code verifying device, which is provided with a verifying means for verifying the correctness of. 2. The two-dimensional code verification device according to claim 1, wherein the reference item set by the reference item setting means includes a variation in the size of a basic pattern forming the two-dimensional code. Two-dimensional code verification device. 3. The two-dimensional code verification device according to claim 1, wherein the reference item set by the reference item setting means includes distortion in the vertical and horizontal directions of the two-dimensional code. apparatus. 4. The two-dimensional code verification device according to claim 1, wherein the reading unit corrects a read error in the read image of the two-dimensional code in units of basic patterns forming a two-dimensional code. A two-dimensional code verification device, characterized in that the reference item set by the reference item setting means includes the number corrected by the error correction function when the two-dimensional code is read by the reading means. 5. The two-dimensional code verification apparatus according to claim 1, wherein the reference item set by the reference item setting unit includes a contrast between printing and non-printing of a basic pattern forming the two-dimensional code. A characteristic two-dimensional code verification device.