Patent ID: 8381983

Claim:
A barcode reading apparatus comprising: a reading section for creating data of a barcode by optically reading a surface of a medium; an image memory for saving the data; a scanning line setup section for setting a plurality of scanning lines for the data saved in the image memory; a decoding section for decoding the barcode with respect to a part of the data corresponding to each of the scanning lines; and a judgment section for calculating a reading reliability that represents a degree of proof against decoding error occurrence in decoding the barcode, by using the data corresponding to the scanning lines, and for selecting a scanning line having a best reliability by making use of the reading reliability; wherein the judgment section comprises: a reading reliability calculation section for calculating the reading reliability of each of the plurality of scanning lines set by the scanning line setup section; a reading reliability judgment section for making a judgment on a best reliability value among the reading reliability values that the reading reliability calculation section calculates; and a scanning line selecting section for making the selection of the scanning line having to the best reading reliability; and wherein the reading reliability calculation section comprises: a marginal difference calculation section for calculating a marginal difference that represents a degree of proof against reading error occurrence with respect to each element datum calculated according to element width values of the barcode, for each of the plurality of scanning lines; and a reading reliability determination section for determination of the reading reliability of each of the scanning lines by selecting a smallest one among the marginal difference values corresponding to the scanning line.