JP2754440B2 - Barcode judgment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bar code judging method for reading a bar code and judging the code. The bar code represents a number or the like by a combination of black and white bars, and is, for example, JAN (Japanese Article Numer).
Is commonly used. This barcode is printed or affixed to a product or the like, and is read at the time of sale of the product, thereby being applied to a receipt issuing process, a product sales statistical process, and the like. Therefore, it is necessary to accurately determine the read barcode.

[0002]

2. Description of the Related Art FIG. 9 is an explanatory view of a bar code. The width of a white bar and a black bar is any one, twice, three or four times as large as 0.33 mm as one module. One character is composed of four bars in the order of a white bar, a black bar, a white bar, and a black bar or the reverse order, and the length of one character is constant at 2.31 mm. With this dimension as a standard, the dimension can be enlarged or reduced in relation to printing accuracy or the like. For the white bar and the black bar, a combination of colors that can obtain a predetermined contrast other than white and black can be used. A left character for six characters and a left guard bar are arranged on the left side of the center bar, and a left margin of 3.63 mm is defined on the left side of the left guard bar. A right character for five characters, a check character, and a light guard bar are arranged on the right side of the center bar, and a light margin of 2.31 mm is defined on the right side of the light guard bar.

FIG. 10 is an explanatory diagram of a character. A left character is composed of one character in the order of a white bar, a black bar, a white bar, and a black bar, has odd parity and even parity, and has a right character. , A black bar, a white bar, a black bar, and a white bar, one character is composed in this order, and only the even parity is included. For example, "0" indicates that the odd parity of the left character is white 3 (0.99 mm), black 2 when the multiple and width of one module are written together with white and black bars.
(0.66 mm), white 1 (0.33 mm), black 1 (0.
33 mm), and the even parity is white 1 (0.33 m
m), black 1 (0.33 mm), white 2 (0.66 mm),
Black 3 (0.99 mm). In the case of the right character, black 3 (0.99 mm), white 2 (0.66 mm), black 1 (0.33 mm), and white 1 (0.33 mm). The odd parity of the left character of “1” is white 2 (0.
69 mm), black 2 (0.63 mm), white 2 (0.69 m
m) and black 1 (0.30 mm). In this case, black 1
Is different from the size of one module, but this is specified to reduce the misreading rate. The numbers 0 to 9 can be represented by such various patterns.

[0004]

When a bar code is optically read and determined, each character is divided based on a left guard bar, a right guard bar or a center bar, and the bar width is measured for each character. Is determined, and based on the result, the determination according to the pattern shown in FIG. 10 is performed. Therefore, there is a drawback that the determination process is complicated because the determination is made on the combination of the bars having four types of widths. Also, when a barcode is read by a card type barcode reader or a pen type barcode reader, it is manually operated.
The reading speed will not be constant, and errors will occur in the measurement of the bar width. Therefore, there is a disadvantage that the misreading rate is increased. An object of the present invention is to reduce the misreading rate by relatively simple processing.

[0005]

The bar code determination method of the present invention will be described with reference to FIG.
A bar code consisting of a combination of a white bar and a black bar of any of double, double, triple and quadruple widths is read by the scanner 1 or the like, and the read signal binarized by the binarization circuit 2 or the like is read. The character separation unit 4 of the code determination unit 3 separates each character consisting of two white bars and two black bars, and then the thick / thin pattern classification unit 5 sets the length of one character to 3/3. The value of 14 times and the width of the read white bar and black bar are compared and classified into two types of thick and thin. Then, the thick and thin pattern regularity determination unit 6 determines the left character and the right character for the center bar. To determine the code based on the regularity of the bold pattern, and for duplicate patterns,
The overlap pattern determination unit 7 determines the code by comparing the widths of the wide widths.

[0006]

A read signal obtained by reading a barcode by the scanner 1 or the like indicates the width of each bar of the barcode. The code judging section 3 is constituted by a processor under program control, etc., and has a character dividing section 4, a thick and thin pattern classifying section 5, a thick and thin pattern regularity judging section 6, an overlapping pattern judging section 7 by a comparison operation function. Etc. can be realized. Since the character is composed of two white bars and two black bars, the character can be easily separated for each character by the character separating section 4. When the length of one character is reduced to 1/7 by the thick and thin pattern classifying unit 5, the size of one module is indicated. It is classified into two types, thick and thin. That is, the length obtained by multiplying the length of one character by 3/14 is used as a criterion. Each bar has a width of one, two, three, or four times the size of one module, so a one-time bar is a thin bar, and a two-, three-, or four-fold bar is a thick bar. Classify as a bar. The code is determined by the thick and thin pattern regularity determination unit 6 based on the regularity of the thick and thin pattern. For example, since the odd parity of the left character of "1" in FIG. 10 is white 2, black 2, white 2, and black 1, the pattern becomes thick, thick, thick, and thin. Since there is no identical pattern, it can be immediately determined to be odd parity "1".

However, in FIG. 10, for example, the even parity "7" of the left character is white 2, black 1, white 3, and black 1, so that the pattern is thick, thin, thick, and thin, and "8" is white. 3, black 1, white 2, and black 1, the pattern is thick, thin, thick, and thin. That is, an overlapping pattern is obtained. In this case, the determination is made by the overlapping pattern determination unit 7,
For the thick bar, “7” is the order of white 2 and white 3 and “8” is the order of white 3 and white 2, so the white bar (A), black bar (B), and white bar (C) and black bar (D), by determining whether (A) <(C),
It can be determined whether “7” or “8”. That is, with respect to the overlapping pattern, the code can be determined by comparing the widths of the wide widths.

[0008]

FIGS. 2 to 6 are flowcharts of an embodiment of the present invention. First, as shown in FIG. 2, a bar code is read (1), and a guard bar and a center bar of the bar code are detected (2). ). Then, the character is separated for each character (3). For example, a bar code is read by the scanner 1 of FIG.
To the left character based on the guard bar or center bar.
Four bars in the order of white, black, white, and black are separated as one character, and in the case of the right character, four bars in the order of black, white, black, and white are separated as one character.

Next, in the thick and thin pattern classifying section 5, the width of each bar is measured based on the signal length of the read signal, and one character length divided for each character is measured. This one
The width of one module is determined by setting the character length to 1/7 (4). If the length of one character is 2.31 mm,
One module is 0.33 mm. Then, the width of one module is multiplied by 1.5. Each bar is compared with the width of each bar, and each bar is classified into thick and thin (5). Therefore, a width of 1.5 times or more of the width of one module is defined as a wide bar, and a narrower bar is defined as a narrow bar. That is, bars of four different widths are classified into bars of two different widths.

Next, as shown in FIG. 3, it is determined whether the character is on the left or right side of the center bar (6).
In the case of the character on the left side (7), a thick pattern is determined (8). For the character shown in FIG. 10, the result of the thick and thin determination is as shown in FIG. A, B, C, D of odd parity of the left character and a, of even parity a,
b, c, d denote a white bar, a black bar, a white bar, and a black bar, and the even parity W, X, Y, Z of the right character.
Indicates a black bar, a white bar, a black bar, and a white bar. For example,
The odd parity "1" of the left character is thick, thick,
Since the patterns are thick and thin, the odd parity 1 is determined by the determination in step (9). As described above, the odd parities 1, 2, 3, 6 and the even parities 1, 2 can be determined by steps (9) to (14).

Further, as shown in FIG.
By (16), the even parities 3 and 6 can be determined. If it is determined in step (17) that the pattern is a thick pattern, a thick pattern, a thin pattern, or a thin pattern, this pattern is determined to have an odd parity of 0.
And an even parity 4. Therefore, in this case, it is determined whether or not A> B (18). That is, as shown in FIG. 10, the odd parity 0 is white 3, black 2, white 1, and black 1, and the even parity 4 is white 2, black 3, white 1, and black 1. In the case of (A)> the relationship of the width of the wide bar of black 2 (B), odd parity 0 is indicated. Even parity 4 will be indicated. Therefore, in step (18), odd parity 0 or even parity 4
Can be determined.

If it is determined in step (19) that the pattern is a thin, thick, thin, or thick pattern, this pattern has an odd parity 7 (white 1, black 3, white 1, black 2) as shown in FIG. And an odd parity 8 (white 1, black 2, white 1, black 3). The odd parity 7 is black 3 (B)> black 2 (D), and the odd parity 8 is black 2 (B). <Black 3 (D)
Therefore, it is possible to determine whether the odd parity 7 or the odd parity 8 by determining whether or not B> D in step (20).

If it is determined in step (21) that the pattern is thick, thin, thin, or thick, the pattern is odd parity 9 (white 3, black 1, white 1, black 2) as shown in FIG. And an even parity 9 (white 2, black 1, white 1, black 3). The odd parity 9 is white 3 (A)> black 2 (D), and the even parity 9 is white 2 (A). <Black 3 (D)
Therefore, it can be determined whether odd parity 9 or even parity 9 in step (22) by determining whether A> D.

As shown in FIG. 5, when it is determined in step (23) that the pattern is thin, thick, thick, or thin,
This pattern is an overlap pattern of odd parity 5 (white 1, black 2, white 3, black 1) and even parity 5 (white 1, black 3, white 2, black 1) as shown in FIG. Parity 5 has a relationship of black 2 (B) <white 3 (C), and even parity 5 has a relationship of black 3 (B)> white 2 (C).
By determining whether B> C in 4), it is possible to determine whether odd parity 5 or even parity 5.

In step (25), fine, thin, thick,
If it is determined that the pattern is thick, this pattern is
0, odd parity 4 (white 1, black 1, white 3,
This is an overlapping pattern of black 2) and even parity 0 (white 1, black 1, white 2, black 3), and odd parity 4 is white 3 (C)
> Black 2 (D) and even parity 0 are white 2 (C) <Black 3
Because of the relationship of (D), in step (26), C
By determining whether or not> D, it is possible to determine whether the odd parity is 4 or the even parity is 0.

Steps (9) to (17), (19),
If the judgment patterns are different from those of (21), (23), and (25), as shown in FIG. 10, even parity 7 (white 2, black 1, white 3, black 1) and even parity 8 (white 3, black 3) are used. Black 1, white 2, black 1), and the even parity 7 is white 2 (A) <white 3 (C) and even parity 8
Has a relationship of white 3 (A)> white 2 (C), so that it is possible to determine even parity 7 or even parity 8 by determining whether A <C in step (27). .

When it is determined in step (7) of FIG. 3 that the character is not the left character, a thick pattern is determined and, as shown in FIG. 6, steps (30) to (36).
To determine even parity 0 to 6. For example, even parity 0 is black 3, white 2, black 1, white 1, thick, thick, thin,
Since the pattern becomes a fine pattern, it can be determined that even parity is 0 in step (30). Similarly, even parity 1 is a black, white 2, black 2, and white 1 thick, thick, thick, and thin pattern, and thus can be determined to be even parity 1 in step (31).

In step (37), it is determined whether or not the pattern is a thin, thick, thin, or thick pattern by determining whether the pattern is an even parity 7 (black 1, white 3, black 1, white 2) as shown in FIG. )
And even parity 8 (black 1, white 2, black 1, white 3), and even parity 7 is white 3 (X)> white 2
(Z) and even parity 8 have a relationship of white 2 (X) <white 3 (Z). Therefore, in step (38), it is determined whether X> Z or not, so that even parity 7 or even parity 8 is determined. Can be determined. Steps (30) to (37)
For patterns other than the judgment pattern by
It can be determined as an even parity 9 (black 3, white 1, black 1, white 2) of a thin or thick pattern.

FIG. 8 shows the above-mentioned overlapping patterns collectively. In the overlapping pattern, there is regularity in the magnitude relation of the thick bars, and therefore the overlapping pattern can be determined by the overlapping pattern determining unit 7 in FIG. 1 based on the regularity of the overlapping pattern. .

The above-described determination step using the thick and thin pattern can be performed in an order other than the above-described embodiment.
It is also possible to execute them in parallel. Further, in the determination by the program control in the code determination unit 3, the determination processing can be performed using a collation table such as a read-only memory.

[0021]

As described above, according to the present invention, a bar code composed of a combination of a white bar and a black bar having a width of one, two, three or four times as large as one module is used for the scanner 1. And the like, and this is binarized by a binarization circuit 2 and the like.
The character separation unit 4 of the code determination unit 3 separates each character consisting of two white bars and two black bars, and then the thick and thin pattern classification unit 5 sets the length of one character to three. By comparing the width of the white bar and the width of the black bar with the value of １４14 times as a criterion, the data is classified into two types, that is, a wide bar and a narrow bar. The determination process is performed by using a combination of bars having widths of two types as a combination of bars having two widths. This has an advantage that the determination process is simplified and the erroneous reading rate can be reduced. In addition, when a combination of two types of bars is used, an overlapping pattern occurs. In this case, since there is a regularity in the magnitude relationship of the actual widths of the classified wide bars, it is easy to use the magnitude relationship based on the magnitude relationship. There is an advantage that can be determined.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a flowchart of an embodiment of the present invention.

FIG. 3 is a flowchart of an embodiment of the present invention.

FIG. 4 is a flowchart of an embodiment of the present invention.

FIG. 5 is a flowchart of an embodiment of the present invention.

FIG. 6 is a flowchart of an embodiment of the present invention.

FIG. 7 is an explanatory diagram of a result of determining the thickness.

FIG. 8 is an explanatory diagram of regularity of an overlapping pattern.

FIG. 9 is an explanatory diagram of a barcode.

FIG. 10 is an explanatory diagram of a character.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Scanner 2 Binarization circuit 3 Code judgment part 4 Character division part 5 Thick and thin pattern classification part 6 Thick and thin pattern regularity judgment part 7 Duplication pattern judgment part

Claims (1)

(57) [Claims] 1. A bar code read signal composed of a combination of a white bar and a black bar having a width of one, two, three or four times as large as one module is read by two white bars and two Next, a value of 3/14 times the length of the one character is compared with the width of the read white bar and the black bar, respectively.
Then, the code is determined for the left character and the right character with respect to the center bar based on the regularity of the thick and thin pattern. For the overlapping pattern of the thick and thin pattern, A bar code determination method comprising comparing the widths of the wide widths to determine the code of the overlapping pattern.