Apparatus and method for correcting bar width, bar code reader, and method for decoding bar code

Abstract

An apparatus for correcting a bar width comprises a detecting section calculating a reference bar width serving as a reference of bar widths, a first calculation section calculating an average value of a plurality of reference bar widths, a second calculation section calculating an error value between a bar width of a bar to be corrected and the reference bar width calculated by the detecting section, and a correcting section correcting the bar width of the bar to be corrected by using the calculated average value when the calculated error value is not less than a predetermined value.

Description

[0001] This is a continuation of Application PCT / JP 99 / 00483 filed on Feb. 4, 1999, now abandonedBACKGROUND OF THE INVENTION[0002] 1. Field of the Invention[0003] The present invention relates to an apparatus and method for correcting a bar width, a bar code reader, and a method for decoding a bar code.[0004] 2. Description of the Related Art[0005] In recent years, as represented by POS systems in distributors, the management of goods or the like is generally performed by bar codes. For example, in a POS system of shops, information such as the type and a price of goods is coded into the format of a bar code, and the bar code is printed on the goods. Thereafter, checkout is performed by reading the bar code on a cash disk, and the number of sold goods are counted on real time. The number of sold goods is used in stock management and buying management.[0006] In order to correctly read a read bar code, the bar width of each of bars constituting the bar code must be correctly recognize...

AI Technical Summary

Benefits of technology

[0026] It is an object of the present invention to provide an apparatus and method for correcting a bar width can appropriately correct a bar width even though thickening and thinning of the bar width of a bar code are not uniform.

[0027] It is another object of the present invention to provide a bar code reader which suppresses a decoding mistake of a character in a correction decoding process and, thereby, can prevent a bar code from being erroneously read, and a method for decoding a bar code therefor.

[0031] According to the second aspect, when the precision difference between the reference bar width and the width of the bar to be corrected is not less than the predetermined value, a correction process for the bar to be corrected is performed by using the average value. For this reason, the precision of correction decoding can be made to be larger than that of a conventional technique, and a bar code can be prevented from being erroneously prevented by a decoding mistake of a character.

Problems solved by technology

As one of the problems in the bar width correction, a problem that the bars of the bar code are thickened or thinned by the degradation of print quality of the bar code is known.

However, when the bar widths of a bar code are locally thickened or thinned by bending or the like when the bar code is pasted on a curved surface, the bar widths are not effectively corrected, and the bar code may be erroneously read.

For this reason, when the number of modules of the black bar is directly calculated, the number of modules may be erroneously calculated.

In this manner, in the conventional bar width correction, a bar width may not be able to be corrected when the bar width is not uniformly thickened or thinned.

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