| 摘要 |
PURPOSE:To improve inspection accuracy by checking the spatial and time isolation of a picture element which is judged to be abnormal in consideration of features of printing. CONSTITUTION:The analog signal of a pattern which is inputted from a detection part 11 is transferred to a frame memory 14 through an A-D converter 13. A reference signal is fetched from the frame memory 14 to a reference memory 15. Then when inspection is performed, the reference signal and inspection signal are sent to a comparing circuit 16 to perform difference arithmetic and a discriminating circuit 17 decides abnormality of printed matter according to a set value. If a picture element exceeding the set value is detected, position information on the point is stored in an abnormality memory 21. The dot stored in the abnormality memory 21 is supplied to an isolation point circuit 18 to check its spatial isolation on the entire printed matter. When there is not any picture element which is decided to be abnormal at the periphery of said defective picture element, it is regarded as a misdecided candidate and its time isolation is checked by using past decision results in the abnormality memory 21. |
