Bar code symbol reading apparatus with double-reading preventing function

摘要

A comparing section compares the coordinates of the four corners of a bar code symbol newly detected by a bar code symbol detecting section and stored in a primary buffer, with the coordinates of the four corners of a bar code symbol having been detected and stored in a secondary buffer. If the coordinates of the newly detected bar code symbol differ from those of the detected bar code symbol, a control section causes a decoding section to decode the bar code symbol on the basis of image data stored in a frame memory. On the other hand, if not so, it is determined that the newly detected bar code symbol is invalid, thereby inhibiting decoding of the same to prevent double-reading.