JP4207367B2 - Bar code reader - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a barcode reader that optically reads and recognizes barcodes.
[0002]
[Prior art]
A bar code displays numbers using white and black parallel bars of several widths, and various standards exist depending on the encoding method. For example, JAN (Japanease Article Number) 13 and JAN8 are defined in “Bar Code Symbol for Common Product Code” of JIS (Japanese Industrial Standard) -X0501.
[0003]
In JIS-X0501, the minimum width of a white bar and a black bar is defined as one module, and 7 modules are assigned to two white bars and a black bar to represent a one-digit data character. Therefore, the thinnest bar is 1 module and the thickest bar is 4 modules. The bar code includes a center bar in the center, data characters arranged on both sides of the center bar, and guard bars arranged outside the data character.
[0004]
The center bar is a module in which five white bars and black bars of one module are arranged in the order of white, black, white, black, and white. The guard bar is one in which three white bars and black bars of one module are arranged in the order of black, white, and black. Moreover, it is prescribed | regulated that the margin part of 7-11 modules may be provided in the outer side of a guard bar as a margin, respectively.
[0005]
JAN13 represents a standard version of 13 digits with 95 modules including guard bars, that is, 30 black bars and 29 white bars. Also, JAN8 represents an 8-digit abbreviated version number with 67 modules including guard bars, that is, 22 black bars and 21 white bars.
[0006]
FIG. 2 is a block diagram showing an example of a conventional barcode reader.
This bar code reading apparatus reads a bar code of JIS-X0501, and has a scanner 1 that reads image data of a certain area including a bar code printed on a form or a product. Further, the barcode reading apparatus includes an image memory 2 that stores the read image data, and a cutting unit 3 that cuts out image data in the barcode area as area data from the image data stored in the image memory 2. An area memory 4 that holds the area data, a recognition unit 10 that recognizes a barcode in the area data, and a control unit 5 that controls the entire apparatus.
[0007]
The recognition unit 10 controls a recognition process and outputs a recognition result, a JAN8 recognition unit 12 that recognizes a JAN8 format barcode based on area data in the area memory 4, and a JAN13 format bar It comprises a JAN 13 recognition unit 13 that recognizes codes.
[0008]
In such a barcode reader, for example, an image such as a form on which a barcode is printed is decomposed into pixels by the scanner 1 and read as image data, and stored in the image memory 2. Subsequently, the cutout unit 3 is activated, and the image data assumed to be a barcode portion is cut out from the image data stored in the image memory 2 and stored in the area memory 4 as area data.
[0009]
Next, the recognition unit 10 is activated, the area data stored in the area memory 4 is read, and a JAN8 format barcode recognition process is performed by the JAN8 recognition unit 12. When the area data is correctly recognized as JAN8, the recognition control unit 11 outputs the recognition result. If it is not recognized as JAN8, the JAN13 recognition unit 13 performs barcode recognition processing in JAN13 format. Then, the recognition result of the JAN 13 recognition unit 13 is output from the recognition control unit 11. Such processing is performed on the area data of all barcode areas in the image data stored in the image memory 2.
[0010]
[Problems to be solved by the invention]
However, the conventional barcode reader has the following problems.
That is, when a barcode is printed on a form or the like, it may be read erroneously due to a void in which a part of the black bar is missing, or a spot generated by dirt or the like adhering to the white bar or margin of the barcode.
[0011]
The present invention solves the problems of the prior art and can reduce the possibility of misreading by determining the authenticity of the barcode read based on the width of each bar constituting the barcode. A bar code reader is provided.
[0012]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides a barcode on which a bar code displaying a predetermined number of codes by arranging a predetermined number of black bars and white bars alternately in parallel is displayed. In the bar code reader for reading and recognizing the area, there is provided determination means for determining the presence or absence of misreading based on the variation in the width of the read black bar and white bar.
[0013]
Further, the determination means compares the difference between the maximum value and the minimum value for each module of the black bar and the white bar with the width per module calculated from the width of the entire barcode, and determines the presence or absence of misreading. It is configured.
[0015]
According to the present invention, since the barcode reader is configured as described above, the following operation is performed.
For the read barcode, the width of the black bar and the white bar constituting the barcode is calculated, and the presence or absence of misreading is determined by the determination means based on the size of the variation.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1 is a block diagram of a bar code reader showing a first embodiment of the present invention. Elements common to those in FIG. 2 are given common reference numerals.
Similar to FIG. 2, this bar code reader reads a bar code of JIS-X0501, and optically scans image data in a certain area including a bar code printed on a form or product. It has a scanner 1 for reading. The bar code reader also includes an image memory 2 for storing the read image data, a cutout unit 3 for cutting out the image data in the bar code area as area data from the image data stored in the image memory 2, and a cutout An area memory 4 is provided for holding the area data.
[0017]
Further, the barcode reading apparatus includes a recognition unit 10A that recognizes a barcode in area data and a control unit 5 that controls the entire apparatus. The recognition unit 10A performs recognition processing control based on an instruction from the control unit 5 and outputs a recognition result OUT. JAN8 recognition recognizes a JAN8 format barcode based on area data in the area memory 4. In addition to the unit 12 and the JAN13 recognition unit 13 for recognizing a JAN13 format barcode, a determination unit (for example, a recognition confirmation unit) 14 is provided. The recognition confirmation unit 14 evaluates the credibility of the recognition result based on the width of each bar of the barcode.
[0018]
FIG. 3 is a flowchart showing the operation of FIG. 1, and FIG. 4 is an explanatory diagram of the processing of the recognition confirmation unit 14 in FIG. Hereinafter, the operation of FIG. 1 will be described with reference to FIGS. 3 and 4.
[0019]
First, the image of the form is read by the scanner 1 of FIG. 1 (step S1), and the read image data is stored in the image memory 2. Subsequently, the cutout unit 3 is activated, and the area data of the barcode area in the image data stored in the image memory 2 is cut out (step S2). The area data cut out by the cutting unit 3 is stored in the area memory 4.
[0020]
Next, the recognition unit 10A is activated, and the JAN8 recognition unit 12 performs recognition processing as a JAN8 format barcode (step S3). If it is not recognized as a correct JAN8 format barcode by the recognition result determination (step S4), the JAN13 recognition unit 13 performs recognition processing as a JAN13 format barcode (step S5). If the barcode is correctly recognized as a JAN8 or JAN13 format barcode, the recognition confirmation unit 14 is activated to determine the authenticity of the recognition result (step S7).
[0021]
As shown in FIG. 4, the recognition confirmation unit 14 aggregates the widths of white bars and black bars for each character in the area data, that is, the number of dots. Next, the maximum value and the minimum value are obtained from the total result of the widths of 1 to 4 modules of the white bar and the black bar, and the difference between the maximum value and the minimum value is calculated. Since the white bar and the black bar each have four types of widths d to 4d from 1 module to 4 modules, a total of 8 differences are obtained.
[0022]
Subsequently, the width d per module is calculated using the width D of the entire barcode. In the case of JAN8 format, since the entire barcode is composed of 67 modules, d = D / 67. Then, it is checked whether or not a difference exceeding the width d exists among the difference between the eight maximum values and the minimum value obtained previously. If it exists, it is determined that there is a possibility of misreading, and the recognition result is discarded. If all the eight differences are less than or equal to the width d, it is determined that the eight characters are correctly recognized, and the recognized data character is output as the recognition result OUT.
Such JAN8 recognition processing, JAN13 recognition processing, and recognition confirmation processing are performed for all barcode areas (steps S8 and S9).
[0023]
As described above, the bar code reader according to the first embodiment has a variation in the width of each bar constituting the bar code (that is, the difference between the maximum value and the minimum value of the width of the white bar and the black bar). ) Based on the recognition confirmation unit 14 for determining the authenticity of the recognition result. Thereby, the possibility of outputting an incorrect recognition result can be reduced.
[0024]
(Second Embodiment)
FIG. 5 is a configuration diagram of a recognition unit showing the second embodiment of the present invention.
This recognition unit 10B is provided in place of the recognition unit 10A in FIG. 1, and has a JAN8 recognition unit 12 and a JAN13 recognition unit 13 similar to the recognition unit 10A. In addition, a determination unit (for example, a module determination unit) 15 is provided instead of the recognition confirmation unit 14, and a recognition control unit 11B having a control content different from that of the recognition control unit 11A is provided correspondingly.
[0025]
The module determination unit 15 determines whether or not the bar code is a legitimate one satisfying the standard, based on the minimum and maximum widths of the center bar and the left and right guard bars in the bar code. . That is, the maximum value Mmax and the minimum value Mmin are obtained within the width d of 11 center bars and guard bars including the white and black bars, and Mmin / Mmax is equal to or greater than a certain value A (where 0 <A ≦ 1). If there is, it is determined that the barcode is valid.
[0026]
FIG. 6 is a flowchart showing the operation of FIG. 5, and FIG. 7 is an explanatory diagram of processing of the module determination unit 15 in FIG. Hereinafter, the operation of FIG. 5 will be described with reference to FIGS. 6 and 7.
[0027]
First, the image of the form is read by the scanner 1 (step S11), and the read image data is stored in the image memory 2. Subsequently, the cutting unit 3 is activated, and area data is cut out from the image data stored in the image memory 2 (step S12). The area data cut out by the cutting unit 3 is stored in the area memory 4.
[0028]
Next, the recognition unit 10B of FIG. 5 is activated, and the module determination unit 15 determines the validity of the center bar and the left and right guard bars in the barcode. As shown in FIG. 7, the module determination unit 15 obtains the width d of the center bar and the left and right guard bars, and obtains the maximum value Mmax and the minimum value Mmin of these 11 widths.
[0029]
Further, it is determined whether or not Mmin / Mmax is equal to or greater than a certain value A (where 0 <A ≦ 1). If this condition is not satisfied, it is considered that the barcode is not correct and the next area is recognized. Processing is performed (steps S17 and S18). If the condition is satisfied, the JAN8 recognition unit 12 performs recognition processing as a JAN8 format barcode (step S14). If it is not recognized as a correct JAN8 format barcode by the determination of the recognition result (step S15), the JAN13 recognition unit 13 performs recognition processing as a JAN13 format barcode (step S16). If it is correctly recognized as a JAN8 or JAN13 format barcode, the data character is output as a recognition result OUT.
Such module determination processing, JAN8 recognition processing, and JAN13 recognition processing are performed for all barcode areas (steps S17 and S18).
[0030]
As described above, the recognition unit 10B according to the second embodiment includes the module determination unit 15 that determines the credibility of the recognition result based on the variation in the width of the center bar and the left and right guard bars constituting the barcode. Have. As a result, it is possible to determine whether or not the barcode is proper by simpler processing than in the first embodiment, and it is possible to reduce the possibility of outputting an erroneous recognition result.
[0031]
In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. Examples of this modification include the following (a) to (c).
(A) Although JAN8 and JAN13 format barcodes defined in JIS-X0501 have been described, the invention can be similarly applied to barcodes of other standards.
[0032]
(B) Although the recognition units 10A and 10B have two recognition units JAN8 and JAN13, the types of barcode standards to be recognized are not limited to two types, and one type or three or more types are recognized. It can be configured as possible.
[0033]
(C) The cutout unit 3, the control unit 5, and the recognition units 10A and 10B may be configured to perform processing by a program using a microprocessor or the like.
[0034]
【The invention's effect】
As described above in detail, according to the present invention , there is provided determination means for determining the presence or absence of misreading based on the variation in the width of the read black bar and white bar. This makes it possible to eliminate bar codes that do not conform to the standard, and reduce the risk of misreading.
[0035]
In particular, the determination means compares the difference between the maximum value and the minimum value for each module of the black bar and the white bar with the width per module calculated from the width of the entire barcode, and determines the presence or absence of misreading. It is configured. As a result, barcodes that do not conform to the standards are surely eliminated, and the possibility of misreading can be reduced.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a barcode reader showing a first embodiment of the present invention.
FIG. 2 is a configuration diagram illustrating an example of a conventional barcode reader.
FIG. 3 is a flowchart showing the operation of FIG. 1;
FIG. 4 is an explanatory diagram of processing of the recognition confirmation unit 14 in FIG. 1;
FIG. 5 is a configuration diagram of a recognition unit showing a second embodiment of the present invention.
6 is a flowchart showing the operation of FIG.
7 is an explanatory diagram of processing of the module determination unit 15 in FIG. 5;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Scanner 2 Image memory 3 Cutout part 4 Area memory 5 Control part 10A, 10B Recognition part 11A, 11B Recognition control part 12 JAN8 recognition part 13 JAN13 recognition part 14 Recognition confirmation part 15 Module determination part

Claims (1)

In a bar code reader that reads and recognizes a bar code area on which a bar code displaying a code with a certain number of digits is arranged in parallel with a predetermined number of black bars and white bars having several different widths.
A determination means for determining the presence or absence of misreading based on variations in the width of the read black bar and white bar ;
The determination means compares the difference between the maximum value and the minimum value for each module of the black bar and the white bar with the width per module calculated from the width of the entire barcode, and determines whether there is a misread. A bar code reader.

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