JP5341951B2 - Code reader and program - Google Patents

Description

  Embodiments described herein relate generally to a code reader and a program.

  Conventionally, a code reader such as a handy scanner that optically reads a barcode such as an EAN (European Article Number) code or a JAN (Japanese Article Number) code is known. This code reader is connected to a POS (Point Of Sale) terminal used in a supermarket or the like via a communication cable or the like, and is used to read a barcode including a product code attached to a product.

  In the conventional code reader described above, when the same reading result is obtained a plurality of times, the reading result is output to the POS terminal, thereby maintaining the reliability of the reading result. However, since the wrong reading result may be obtained a plurality of times, it has been desired to further improve the reliability of the reading result.

In order to solve the above-described problem, a code reading apparatus according to an embodiment includes a reading unit that reads a barcode, a decoding unit that decodes a code included in the barcode, and a barcode corresponding to the decoded code. Based on the amount of deviation between the gap and bar width and the gap and bar width in the read barcode , the decoded code when the code included in the barcode to be read is read. comprising a calculating means for calculating reliability, and an output means for outputting the decoded code depending on the calculated reliability.

The program of the embodiment includes a decoding unit that decodes a code included in a barcode read by a reading unit that reads a barcode, a barcode gap and a bar width corresponding to the decoded code , Calculation to calculate the reliability of the decoded code when reading the code included in the barcode to be read based on the deviation amount between the gap and the width of the bar in the read barcode means, and output means for outputting the decoded code depending on the calculated reliability, it is to function.

FIG. 1 is a perspective view illustrating an overview of a code reading apparatus according to an embodiment. FIG. 2 is a block diagram illustrating a hardware configuration of the code reading apparatus according to the embodiment. FIG. 3 is a block diagram illustrating a functional configuration realized by the CPU. FIG. 4 is a conceptual diagram showing an example of a barcode. FIG. 5 is a table showing the relationship between the widths of the four elements of each character and the assigned numerical values. FIG. 6 is a table showing that a single-digit numerical value is derived by a combination of numerical sets. FIG. 7 is a schematic diagram showing the measurement of each character in the barcode. FIG. 8 is a table showing the correspondence of decoding in the barcode. FIG. 9 is a graph showing a correspondence relationship between the average deviation amount and the reliability. FIG. 10 is a flowchart illustrating an example of the operation of the code reading apparatus according to the embodiment. FIG. 11 is a conceptual diagram illustrating output of a read code based on reliability in the case of a full segment. FIG. 12 is a conceptual diagram illustrating output of a read code based on reliability in the case of a half segment. FIG. 13 is a conceptual diagram illustrating output of a read code based on reliability in the case of a full segment.

  Hereinafter, a code reading apparatus and a program according to an embodiment will be described with reference to the drawings. The code reading device may be a handy scanner or the like that reads a barcode attached to a product when registering and paying for the product related to one transaction. In the embodiment, a code reading device used by connecting to a POS terminal installed in a restaurant or a store such as a supermarket will be described as an example.

  FIG. 1 is a perspective view illustrating an overview of a code reading device 100 according to an embodiment. As shown in FIG. 1, a code reading apparatus 100 according to an embodiment includes a casing 101 having a barcode reading unit 204 (see FIG. 2) that reads a barcode therein, a grasping unit 102, an operation switch 103, and a communication cable 104. It is configured with. The grasping unit 102 is a part that is provided in the housing 101 and grasps with one hand when the operator operates the code reading device 100. The operation switch 103 receives an operation input from the operator. The operator grasps and operates the grasping unit 102 with one hand, thereby reading a barcode or the like by the code reading device 100 and performing an operation input via the operation switch 103. The communication cable 104 is connected to a terminal device 300 (see FIG. 2) such as a POS terminal. Information such as a barcode read by the code reading device 100 is output to the terminal device 300 via the communication cable 104.

  FIG. 2 is a block diagram illustrating a hardware configuration of the code reading apparatus 100 according to the present embodiment. As shown in FIG. 2, the code reading apparatus 100 includes a CPU 201 (Central Processing Unit), a ROM 202 (Read Only Memory), a RAM 203 (Random Access Memory), a barcode reading unit 204, a communication unit 205, and an operation unit 206. Composed. Each component included in the code reading device 100 is connected to be communicable with each other via a bus 208.

  The CPU 201 centrally controls the operation of the code reading device 100. Specifically, the CPU 201 develops a program stored in the ROM 202 in the work area of the RAM 203 and sequentially executes the program, thereby outputting a control signal to each part of the code reading device 100 to control the operation of the code reading device 100. To do. The ROM 202 stores data such as programs and setting information read and executed by the CPU 201. The RAM 203 provides a work area for the CPU 201.

  The barcode reading unit 204 is a scanner for optically reading a barcode in which gaps and bars are arranged under the control of the CPU 201. Specifically, the barcode reading unit 204 may be LED (Light Emitting Diode) illumination, a CCD (Charge Coupled Device) image sensor, a laser scanner, or the like. Note that the barcode of this embodiment may be an EAN code, a JAN code, or the like, in which gaps and bars are arranged with a width corresponding to a code such as a product code. In the code reader 100, the gap and bar width arranged as a barcode are read by the barcode reader 204, and decoded by the code decoder 2011 (see FIG. 3) based on the read gap and bar width. The code is read from the barcode.

  The communication unit 205 performs data communication with a terminal device 300 such as a POS terminal connected via the communication cable 104 (see FIG. 1) under the control of the CPU 201. Specifically, the communication unit 205 communicates with the terminal device 300 via a USB (Universal Serial Bus) or the like. The operation unit 206 receives an operation input from the operator via the operation switch 103 (see FIG. 1) and outputs it to the CPU 201.

  Next, functional units of the code reading apparatus 100 realized by the CPU 201 executing the program sequentially will be described with reference to FIG. FIG. 3 is a block diagram illustrating a functional configuration realized by the CPU 201. As illustrated in FIG. 3, the CPU 201 has functions as a code decoding unit 2011, a reliability calculation unit 2012, and an output unit 2013 by sequentially executing programs.

  The code decoding unit 2011 acquires the code by decoding the barcode read by the barcode reading unit 204. Specifically, the code decoding unit 2011 performs conversion into a code corresponding to the gap and the bar width according to a preset conversion formula based on the read bar code gap and bar width.

  Here, details of barcode decoding in the code decoding unit 2011 will be described. In the following description relating to decoding, JISX0501-1985 (barcode symbol for common product code) and JISX0507-2004 (barcode symbol-EAN / UPC-basic specification) which are JIS standards relating to JAN code (EAN code) In particular, JISX0501 is referred to the chart on page 2, and JISX0507 is referred to on pages 3, 5, 14, and 15. FIG. 4 is a conceptual diagram showing an example of the barcode BC.

  As shown in FIG. 4, the barcode BC is, for example, a 13-digit JAN code (EAN code), and is composed of a total of 113 modules with one module as a basic unit. The width of one module is basically 0.33 mm, and 0.8 to 2.0 times (0.264 to 0.660 mm) is accepted as the standard of JAN code. The barcode BC is composed of a left margin, a left guard bar, a data character (left side), a center bar, a data character (right side), a modular check character, a right guard bar, and a right margin from the left. The central center bar is composed of five modules of black (bar), white (gap), black, white, and black. The left data character is composed of 6 characters, the right data character is composed of 5 characters, the modular check character is composed of 1 character, and each character is composed of 7 modules.

  In the bar code BC, the data character on the left side is composed of four elements of white, black, white and black. The right data character and the modular check character are composed of four elements of black, white, black, and white. Each element has a width of 1-4 modules. However, the total of 4 elements is 7 modules. In the barcode BC, the country code C1 and the product manufacturer code C2 are described in the left data character, that is, the left half segment of the barcode BC. In the right data character and the modular check character (right half segment), a product item code C3 and a modular check character C4 are described.

  FIG. 5 is a table showing the relationship between the widths of the four elements of each character and the assigned numerical values. In the table shown in FIG. 5, S means white (gap) and B means black (bar). The numerical value in S or B means the width of the element (gap or bar). Further, the width of the elements of the number set A or the number set B is assigned to the left data character, and the width of the elements of the number set C is assigned to the right data character and the modular check character.

  FIG. 6 is a table showing that a one-digit numerical value is derived by a combination of numerical sets. As shown in FIG. 6, a one-digit numerical value is derived based on the combination of the number set types in the left data character (six characters). For example, when the type of the number set of 1 to 6 characters in the left data character is A, A, B, A, B, B, “1” is derived as a one-digit numerical value.

FIG. 7 is a schematic diagram showing the measurement of each character in the barcode BC. The upper side of FIG. 7 shows the measurement of one character (four elements from the left, bar BR1, gap SP1, bar BR2, and gap SP2) in the number set C. Further, the lower side of FIG. 7 shows measurement of one character (four elements from the right, bar BR1, gap SP1, bar BR2, and gap SP2) in the number set A and the number set B. If the width S from the top edge to the next character and 7 modules, bar BR1 and form a width _{e 1} and forming the width _{e 2} gap SP1 and bar BR2 gap SP1 will width of 2-5 modules. The value of each character is decoded and obtained by a combination of determinants E ₁ and E ₂ based on the width e ₁ and the width e ₂ .

FIG. 8 is a table showing the correspondence of decoding in the barcode BC. As shown in FIG. 8, the combinations of determinants E ₁ and E ₂ that are integer values based on the width e ₁ and the width e ₂ that are the number of pixels in the number sets A, B, and C are the _first . As a determining factor, the numerical value of the character is decoded. However, if the combination has the same value, the numerical value cannot be decoded by the first determining factor, so the width b _{1 of the} bar BR1 (see FIG. 7) and the width b _{2 of the} bar BR2 (see FIG. 7) are used. Discrimination is performed using the second determination factor. For example, in the case of the number set A, since the numerical values of the characters “1” and “7” and “2” and “8” are the same value, the numerical values cannot be decoded by the first determining factor. Therefore, the numerical value of the character is decoded by the second determinant that compares the total value (b ₁ + b ₂ ) of the width b ₁ and the width b ₂ with a predetermined threshold.

In the decoding in the code decoding unit 2011, a numerical value to be decoded with a certain degree of allowance is assigned. Specifically, the width e ₁ and the width e ₂ are obtained as real values, but the numbers after the decimal point are rounded to an integer to obtain a value of 2 to 5.

More specifically, the reference threshold values RT1, RT2, RT3, RT4 and RT5 are determined as follows.
RT1 = (1.5 / 7) S
RT2 = (2.5 / 7) S
RT3 = (3.5 / 7) S
RT4 = (4.5 / 7) S
RT5 = (5.5 / 7) S
In each character, the width e ₁ and the width e ₂ (real values) and the above-described reference threshold are compared as follows to make an integer.
If RT1 ≦ e _i <RT2, set E _i = 2. (I = 1, 2)
If RT2 ≦ e _i <RT3, then E _i = 3. (I = 1, 2)
If RT3 ≦ e _i <RT4, then E _i = 4. (I = 1, 2)
If RT4 ≦ e _i <RT5, E _i = 5. (I = 1, 2)
Thus, the width e ₁ and the width e ₂ (real values) are set to integer values of 2, 3, 4, or 5.

  Returning to FIG. 3, the reliability calculation unit 2012 calculates the reliability of the code decoded by the code decoding unit 2011 with respect to the code included in the read barcode. Here, the reliability is a numerical value indicating the reliability of the read code (decoded code) when the code included in the barcode to be read is read. Specifically, when the code included in the barcode to be read is a true value, the code decoded by the code decoding unit 2011 due to the effects of barcode printing quality, illumination at the time of reading, noise mixing, and the like. May deviate from the true value. For example, when the code included in the barcode to be read is “491234678904”, the decoded code may be decoded as “492123678902”. The reliability calculation unit 2012 calculates the reliability indicated by a numerical value between 0 and 1 indicating whether or not a decoded code is obtained without deviating from the true value described above in one reading. In addition, about the reliability calculated, not only the numerical value between 0-1, but the numerical value of percent notation may be sufficient.

Specifically, the reliability calculation unit 2012 compares the gap and the width of the bar corresponding to the barcode corresponding to the decoded code with the gap and the width of the bar in the read barcode. Based on the above, the reliability is calculated. For example, assuming that each character is printed with an ideal width in the bar code BC, the determination factors E ₁ and E ₂ are any of 2.0, 3.0, 4.0, and 5.0. Value. However, in actuality, the value deviates from the true value due to the influence of print quality, noise, and the like. The shift amount d _i is obtained by the following equation 1.

  Further, the average shift amount D of each character is obtained by the following equation 2.

  Here, the average shift amount D can take a value of -0.5 to 0.5. Based on this average deviation amount D, the reliability c of each character is obtained by the following equation (3).

  In addition, you may obtain | require the reliability c of each character by the following formula | equation 4.

  FIG. 9 is a graph showing a correspondence relationship between the average deviation amount D and the reliability. As shown in FIG. 9, the reliability decreases as the average shift amount D departs from zero. It should be noted that, rather than calculating the reliability using equation 3, the reliability decreases according to the average deviation amount D moving away from 0 when the reliability is calculated using equation 4. For this reason, the reliability can be estimated more severely by switching the calculation method of the reliability from Expression 3 to Expression 4.

  Next, based on the reliability c of each character, the reliability C of the segment constituting the barcode BC is obtained by the following equation (5).

  Returning to FIG. 3, the output unit 2013 outputs the code decoded by the code decoding unit 2011 to the terminal device 300 via the communication unit 205 as a code read according to the reliability calculated by the reliability calculation unit 2012. To do. Specifically, when the calculated reliability exceeds a predetermined threshold, the output unit 2013 outputs a code with the calculated reliability to the terminal device 300. Therefore, in the terminal device 300, when the operator causes the code reading device 100 to read the barcode BC to be read, a highly reliable code of the reading result can be obtained.

  Next, the operation of the code reading apparatus 100 will be described in detail. FIG. 10 is a flowchart illustrating an example of the operation of the code reading device 100 according to the embodiment.

  As shown in FIG. 10, when processing is started according to an operation input by the operation switch 103 or the like, the CPU 201 sets the reliability calculation method when the reliability calculation unit 2012 calculates the reliability, that is, as described above. A setting is made as to which of the calculation formulas of Formula 3 or Formula 4 is used to calculate the reliability (S10). Specifically, an operation input such as an operator's selection operation is accepted by the operation unit 206 as setting means, and a reliability calculation method is set. The setting of the reliability calculation method may be performed in advance by the operation unit 206 and may be performed by reading setting information stored in advance in the ROM 202 or the like. In this way, by making it possible to set the reliability calculation method, the tolerance for reading barcodes can be changed according to the operation.

  Next, the CPU 201 starts reading the barcode by the barcode reading unit 204 (S11). When barcode reading by the barcode reading unit 204 is started, the code decoding unit 2011 acquires the code by decoding the barcode read by the barcode reading unit 204 (S12). Next, the reliability calculation unit 2012 calculates the reliability of the code decoded by the code decoding unit 2011 (S13).

  The reliability calculated in S13 is temporarily stored in the RAM 203 together with the decoded code. When the barcode reading unit 204 sequentially reads barcodes, the calculated reliability is accumulated in the RAM 203 and stored for each decoded code. For example, it is assumed that the barcode is read three times by the barcode reading unit 204, and “4921345678904” is obtained twice and “4921345678902” is obtained once as decoded codes. In this case, the reliability for two times “492123678904” is accumulated and stored in the RAM 203, and the reliability for one time “492123678902” is stored in the RAM 203.

  Next, the output unit 2013 determines whether or not the reliability calculated by the reliability calculation unit 2012 exceeds a predetermined threshold set in advance in the ROM 202 or the like (S14). If the calculated reliability exceeds a predetermined threshold (S14: YES), the code decoded by reading is sufficiently reliable, and the output unit 2013 outputs the decoded code to the terminal device 300 (S15). , The process proceeds to S16. If the calculated reliability does not exceed the predetermined threshold (S14: NO), the code decoded by reading is not sufficiently reliable, and the output unit 2013 performs the process to S16 without outputting the decoded code. To proceed.

  In S16, the CPU 201 determines whether or not to end the process in accordance with an operation input such as the end of reading by the operation switch 103 (S16). When continuing without terminating the process (S16: NO), the CPU 201 returns the process to S12. When the process is to be ended (S16: YES), the CPU 201 ends the reading of the barcode by the barcode reading unit 204 and ends the process.

  The code reader 100 calculates the reliability for each segment constituting the read barcode, and if the reliability of all the segments exceeds a predetermined threshold, the decoded code is sent to the terminal device 300. It may be output. As described above, it is possible to improve the reliability of the reading result by checking the misreading for each segment. Specifically, in S13, the reliability calculation unit 2012 calculates the reliability of the code included in the segment for each segment constituting the barcode read by the barcode reading unit 204, and determines the reliability of each segment. The degree is temporarily stored in the RAM 203. Next, in S14, the output unit 2013 outputs the decoded code to the terminal device 300 when the reliability of all the segments (for full segments) constituting the read barcode exceeds a predetermined threshold.

  FIG. 11 is a conceptual diagram illustrating output of a read code based on reliability in the case of a full segment. As shown in FIG. 11, by reading the barcode several times, the RAM 203 stores the decoded read code (full segment) such as “4921345678904” and “4921345678902” and the integrated value of the reliability for the read code. Remembered. The output unit 2013 validates a segment whose reliability stored in the RAM 203 exceeds a threshold value of about 1.8, for example. In the illustrated example, “492123678904” having a reliability of “2.2” is valid. Next, the output unit 2013 reads the validated code from the RAM 203 and determines whether or not the read code is for the full segment. When there are valid segments for the full segment, the output unit 2013 outputs the code to the terminal device 300. In the illustrated example, since “49123456789904” that has been validated exists for the full segment, it is output to the terminal device 300 as it is.

  FIG. 12 is a conceptual diagram illustrating output of a read code based on reliability in the case of a half segment. As shown in FIG. 12, by reading the barcode several times, the RAM 203 reads “492345” which is the reading code for the left half segment, and “678902” and “672904” which are the reading codes for the right half segment. And the integrated value of reliability for the read code is stored. It is assumed that the left half segment “492345” and the right half segment “672904” are valid. The output unit 2013 reads the respective codes that are valid in the left and right half segments, and checks the matching of the check character for the read full segment codes. Next, when the matching of the check character is confirmed, the output unit 2013 outputs to the terminal device 300 codes for the full segments that are valid in the left and right half segments. In the illustrated example, “492123672904”, which is a combination of “492345” of the left half segment and “672904” of the right half segment, is output to the terminal device 300.

  Further, the output unit 2013 outputs, to the terminal device 300, a code for which a large reliability is calculated when the difference in reliability exceeds a predetermined threshold among a plurality of codes stored in the RAM 203. May be. Specifically, the output unit 2013 sorts the reading codes stored in the RAM 203 in descending order of reliability, and the difference in reliability between the code with the highest reliability and the next largest code is predetermined. It is determined whether or not the threshold value is exceeded. Then, the output unit 2013 outputs a code having the highest reliability to the terminal device 300 when the difference in reliability exceeds a predetermined threshold.

  If the conditions at the time of reading (the angle of the code reading device 100 with respect to the barcode, illumination, etc.) are favorable, the reliability of the code that has been correctly read increases, and there is a sufficient difference from the reliability of the code that has not been read correctly. growing. Therefore, when the difference in reliability between the code with the highest reliability and the next largest code is sufficiently large, the code with the highest reliability is output to the terminal device 300, so that the read result Reliability can be improved.

  FIG. 13 is a conceptual diagram illustrating output of a read code based on reliability in the case of a full segment. As shown in FIG. 13, decoded read codes (full segments) such as “492123678904” and “491234678902” are sorted in descending order of reliability, and the values of reliability are compared with each other. Then, when there is a difference of 1.5 or more as the predetermined threshold, for example, “492123678904” having a high reliability is validated, and “49123456789904” validated is output to the terminal device 300.

  The code reading device 100 of the embodiment includes a control device such as a CPU, a storage device such as a ROM (Read Only Memory) and a RAM, an external storage device such as an HDD and a CD drive device, a display device such as a display device, It has an input device such as a keyboard and a mouse, and has a hardware configuration using a normal computer.

  The program executed by the code reading apparatus 100 according to the embodiment is a file in an installable format or an executable format, and is a computer such as a CD-ROM, a flexible disk (FD), a CD-R, a DVD (Digital Versatile Disk). It is recorded on a readable recording medium and provided.

  The program executed by the code reading apparatus 100 according to the embodiment may be configured to be provided by being stored on a computer connected to a network such as the Internet and downloaded via the network. The program executed by the code reading apparatus 100 according to the embodiment may be provided or distributed via a network such as the Internet. Further, the program of this embodiment may be configured to be provided by being incorporated in advance in a ROM or the like.

  The program executed by the code reading apparatus 100 according to the embodiment has a module configuration including the above-described units (code decoding unit 2011, reliability calculation unit 2012, and output unit 2013). As actual hardware, a CPU ( The processor) reads out the program from the storage medium and executes the program, so that each unit is loaded onto the main storage device and generated on the main storage device.

  In the above-described embodiment, the configuration in which the CPU 201 of the code reading apparatus 100 provides functions as the code decoding unit 2011, the reliability calculation unit 2012, and the output unit 2013 by executing a program has been exemplified. However, the code decoding unit 2011, the reliability calculation unit 2012, and the output unit 2013 may be realized by the CPU on the terminal device 300 side executing the program.

    DESCRIPTION OF SYMBOLS 100 ... Code reading apparatus 101 ... Housing | casing 102 ... Grasping part 103 ... Operation switch 104 ... Communication cable 201 ... CPU, 202 ... ROM, 203 ... RAM, 204 ... Bar code reading part, 205 ... Communication part, 206 ... Operation unit 208 ... Bus 300 ... Terminal device 2011 ... Code decoding unit 2012 ... Reliability calculation unit 2013 ... Output unit BC ... Bar code BR1, BR2 ... Bar C1 ... Country code C2 ... Product manufacturer code, C3 ... Product item code, C4 ... Modular check character, SP1, SP2 ... Gap

JP 2001-175805 A

Claims (6)

Reading means for reading a barcode;
Decoding means for decoding a code included in the barcode;
A gap and the width of the bars of the bar code corresponding to the decoded code, on the basis of the shift amount between the gap and the width of the bars in the read barcode, the code contained in the bar code of the read target A calculation means for calculating the reliability of the decrypted code at the time of reading ;
Output means for outputting the decoded code in accordance with the calculated reliability;
A code reader comprising: The output means outputs the decoded code when the calculated reliability exceeds a predetermined threshold;
The code reader according to claim 1. Storage means for storing the code decoded by the decoding means and the reliability calculated for the decoded code;
The output means outputs a code having a greater reliability when the difference in reliability exceeds a predetermined threshold among the plurality of codes stored in the storage means.
The code reader according to claim 1. Setting means for setting a calculation method for calculating the reliability based on the deviation amount;
The calculation means calculates the reliability according to a calculation method set by the setting means;
The code reading device according to any one of claims 1 to 3. The calculation means calculates, for each segment constituting the read barcode, a reliability of a decoded code with respect to a code included in the segment,
The output means outputs the decoded code when the calculated reliability concerning all the segments constituting the read barcode exceeds a predetermined threshold,
The code reader according to any one of claims 1 to 4. Computer
Decoding means for decoding the code included in the barcode read by the reading means for reading the barcode;
A gap and the width of the bars of the bar code corresponding to the decoded code, on the basis of the shift amount between the gap and the width of the bars in the read barcode, the code contained in the bar code of the read target A calculation means for calculating the reliability of the decrypted code at the time of reading ;
Output means for outputting the decoded code in accordance with the calculated reliability;
Program to make it function.

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