READING AND DISCRIMINATING METHOD FOR BAR CODE

PURPOSE:To improve read and decision accuracy in the presence of a bar code by judging that an input image is not a bar code when the length of a window reduced so that only the input image is put therein is smaller than set minimum length in the extension direction of a single bar code. CONSTITUTION:A comparator 9 compares the window width (length in the extension direction of the single bar code) as the window length of a new window with the set minimum width to judge whether or not the new window width is larger than the set minimum width, thereby outputting data on it. The output data of the comparator 9 is inputted to a central arithmetic processor (CPU)10. The CPU10 judges that there is no bar code when the new window width is smaller than the set minimum width and outputs a signal indicating that the number of bar codes is 0. Further, when the new window width is larger than the set minimum width, it is judged that there is a bar code and a signal expressing its contents is outputted.