| 摘要 |
PURPOSE:To accurately inspect a printed face by equally dividing an image pickup range into plural dots, binarizing respective dots by a prescribed threshold and checking whether the numbers of dots in respective intermediate points of the width of a bright part of a code and the width of its dark part are included in an allowable range or not. CONSTITUTION:The image pickup range (code window) of the printed face is picked up by a TV camera and equally divided into vertical and horizontal dots by the horizontal scanning line of a video signal and a prescribed clock signal and binarized to bright and dark parts by the prescribed threshold. Whether the numbers of dots in the intermediate points of the widths of the bright and dark parts and the total number of dots in the bright or dark part are included in the allowable range or not is inspected. In addition, the ratio of the reference value of the total number of dots of the dark part on the printed face to the measuring value of the total number of dots of the dark part is set up as a correction coefficiency, the correction coefficiency is multiplied by the number of dots of the dark part of each code and w hether the multiplied result is included in an allowable range or not is checked to inspect code lacking or code clogging. On the other hand, the position of the printed face is found out by a binary signal and compared with a reference position and the width of each signal in the horizontal/vertical scanning direction is found out from the binary signal to check whether the width is included within an allowable range or not. In this constitution, a code can be detailedly and accurately detected and the continuity of the code, the density of ink, a printing shear, and the size of the code can also be inspected. |
