JPH11232377A - Bar code reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bar code reader that can surely read a bar code of shorter height. SOLUTION: A bar code reader has a scanning part 16, a character string detection part 18 and a synthesizing part 20. The character string detection part 18 detects the first character string having a start code, the second character string having an end code and an intermediate character string having both a character in the last column of the first character string and character of a leading column of the second character string. The synthesizing part 20 synthesizes a perfect character string by combining the first character string and the intermediate character string by way of a column common to the first character string and the intermediate character string and combining the intermediate character string and the second character string by way of the column common to the intermediate character string and the second character string.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bar code reader for reading information on an article by scanning a bar code label attached to the article with a laser beam or the like and detecting reflected light. The invention relates in particular to a bar code reader which makes it possible to reduce the height of the bar code (the length dimension of the bar).

[0002]

2. Description of the Related Art For example, in a sorting / shipping center for goods and goods, a scanning section of a barcode reader is fixed above a belt conveyor, and a barcode label attached to an article being conveyed by the belt conveyor is scanned with a laser beam. The bar code is decoded by scanning and detecting the reflected light. The orientation of the articles on the conveyor (and thus the orientation of the barcode labels) can vary from article to article. In order to ensure that the bar code is read with a small number of scanning lines regardless of the difference in the direction, in the related art, the oblique angle of the scanning line of the laser beam with respect to the conveying direction of the conveyor is, for example, 45 °. Scanning is performed in a scanning pattern.

When such an oblique scanning pattern is employed, one set of bar codes cannot be completely scanned by one scanning line. Therefore, in the related art, as shown in FIG. 4, a first character string including a start code is detected by one scanning line (scanning line A), and another scanning line (scanning line A) is detected. B) the second containing the end code
It is proposed that the first character string and the second character string be combined through a common digit included in both the first and second character strings to synthesize a complete character string. (Eg, JP-A-1-96683 and JP-A-5-165996)
issue).

[0004]

As can be seen from FIG. 4, in this system, each bar A and B has a total number of digits (a complete character including a start code, an end code and character data) in a bar code. 1/2 of the number of digits in the column) plus 1
A height (dimension in the length direction of the bar) that intersects the width of ((total number of digits / 2) +1) is essential. An object of the present invention is to provide a bar code reader capable of reliably reading a shorter bar code.

[0005]

The bar code reader according to the present invention is also called a three-part system, in which a set of bar codes is divided into three parts to detect three partial character strings.
A complete character string is synthesized by combining two character strings. That is, the bar code reader of the present invention scans a bar code label attached to an article with a light beam, detects reflected light, outputs a signal corresponding to the bar code, and outputs a signal according to the bar code. A first character string having a start code, a second character string having an end code, and an intermediate character having both the last character of the first character string and the first character of the second character string. A character string detecting unit for detecting a character string, and a combining unit for combining and outputting a complete character string from the first character string, the intermediate character string, and the second character string.

As described above, since the three-part system is used, each character string can be detected even if the height of the bar code is reduced, and the height of the bar code is reduced by about 25 as compared with the conventional system.
% Can be reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a bar code reader 10 according to the present invention includes a scanning unit 16 having a light projecting unit 12 and a light receiving unit 14, a character string detecting unit 18, and a synthesizing unit 20. It is composed of

[0010] The light projecting unit 12 reads a bar code of one bar code label attached to an article being transported by a belt conveyor or the like along three scanning lines A, B, and C as shown in FIG. Scan by laser beam. In FIG. 2,
The characters in each digit of the bar code are shown in different patterns instead of the actual black and white bars in order to facilitate the distinction between adjacent characters. The light receiving section 14 is provided for each of the scanning lines A, B,
The reflected light from the barcode is detected for each C, and an electric signal corresponding to the reflected light is output to the character string detecting unit 18.

In the example shown in FIG. 2, it is assumed that the bar code is composed of 5-digit character data, a start code, and an end code. The character string detector 18 scans each scanning line A,
For each of B and C, an output signal having at least three digits of information including a start code and an end code is adopted as a valid signal, and an output signal having two or less digits of information is excluded.

The character string detector 18 first checks whether an output signal obtained by scanning along the scanning line A contains a start code. If the start code is included, it is checked whether ASCII conversion can be performed on the character data of the first digit, the second digit, and the like after the start code.
Convert to a code, create and store a first character string with a start code.

Next, the character string detecting section 18 checks whether or not an output signal obtained by scanning along the scanning line B contains a start code. If a start code is included, a first character string having a start code is created and stored in the same manner as described above for the scanning line A. If the output signal of the scanning line B does not include a start code, it is next checked whether or not an end code is included. If the end code is not included, the output signal is stored as character data and ASCII conversion is performed. If the conversion is successful, the obtained character string is stored as an intermediate character string (a character string that does not include any of the start code and end code).

If ASCII conversion fails,
As shown in FIG. 3, the ASC is shifted by one black bar again.
Perform II conversion. If the ASCII conversion still cannot be performed, the ASCII conversion is performed again by shifting one black bar. In the same manner, the operation is repeated until the ASCII conversion can be performed, and the ASCII converted character string is stored as an intermediate character string.

Next, the character string detecting section 18 checks whether or not an output signal obtained by scanning along the scanning line C includes an end code. If the end code is included, check if the character data before the end code can be converted to ASCII,
If it can be converted, it is converted to ASCII code, and a second character string having an end code is created and stored.

Thus, the first character string, the intermediate character string,
When the first character string and the second character string are obtained, the synthesizing unit 20 transmits the first character string and the intermediate character string via the common digit of the first character string and the intermediate character string (the second digit of the character data in the example of FIG. 2). Combine with a string and save the resulting string as a combined string. Further, the synthesizing unit 20 combines the combined character string and the second character string via the common digit (the fourth digit of the character data in the example of FIG. 2) between the intermediate character string and the second character string, Composes a string.
The resulting string is output as a complete string.

Although the example in which the barcode is composed of five-digit character data has been described above, the barcode can be composed of character data of any desired number of digits.

[0016]

According to the present invention, a set of bar codes is
Since the complete character string is recognized by detecting the divided partial character strings and combining the three divided character strings, it is sufficient to scan one set of barcodes with three scanning lines. Therefore, the barcode can be read even if the height of the barcode is shortened. For example, if the total number of digits of the barcode is 7
In the case of digits (including a start code, an end code, and character data, and the character data is 5 digits), for example, in a conventional method, a bar code of only 4/7 of the total number of digits is scanned. In contrast to the need for height, according to the present invention, a signal of 3/7 digits of the total number of digits for each of the scanning lines A, B, and C is taken into the character string detection unit 18 to form one set. A complete character string of a barcode can be synthesized. Therefore, according to the present invention, the height of the barcode is reduced by about 25 as compared with the conventional method.
%. As a result, the height of the barcode label can be reduced, and the area of the article covered with the barcode label can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of a barcode reader according to the present invention.

FIG. 2 is a view showing that a bar code is read by being divided into three character strings by three scanning lines according to the present invention. Each digit of the bar code is replaced with an actual black and white bar instead of being shown by an actual black and white bar. It is shown in a different pattern.

FIG. 3 shows a state in which ASCII conversion is performed while shifting a black bar.

FIG. 4 shows a bar code read by two scanning lines according to a conventional method.

[Explanation of symbols]

 10: Barcode reading device 12: Light emitting unit 14: Light receiving unit 16: Scanning unit 18: Character string detecting unit 20: Synthesizing unit

Claims (1)

[Claims] 1. A scanning section for scanning a bar code label attached to an article with a light beam, detecting reflected light and outputting a signal corresponding to the bar code, and a start code based on an output signal from the scanning section. And a second character string having an end code, and an intermediate character string having both the last character of the first character string and the first character of the second character string. A bar code reading device comprising: a character string detecting unit; and a combining unit that combines and outputs a complete character string from the first character string, the intermediate character string, and the second character string.