| 摘要 |
PURPOSE:To simplify the structure of an automatic sensing discharger as well as improve the speed and accuracy of inspection by a method in which the histogram of each picture face is compared with the histogram of good picture face and when a difference more than a given value is detected, the printing of the picture face is judged as defective, and the defective printing is discharged from the printing line. CONSTITUTION:During the running period of printing 1, the video signal of each paper face (picture face) obtained by the image pickup of an image sensor 2 is converted into digital signal of a form to show the tonal levels of each stage for the picture face in the A/D converter of A/D-D/A converter unit 3 and the stored in a picture memory unit 4. In a histogram arithmetic unit 5, a histogram or data to show the degree (dot number) distribution for tonal level groups for each picture data are prepared from data on picture faces to be stored in order and data on stored reference pictures. In a CPU unit 7, the histogram S of picture data to be renewed and stored in order is compared with the histogram R of the reference picture data. When there appears histogram S beyond a given allowable value as compared with the histogram S, command E and warning signal A to discharge the paper from the printing line are sent out through a parallel input and output unit 9. |
