| 摘要 |
PURPOSE:To provide a printed matter inspection apparatus dispensing with the positional adjustment of a detector and capable of coping with the printing elongation of printing paper, by comparing the same parts of the same patterns printed on the same paper surface in series in a feed direction by one self- scanning type photoelectric converter. CONSTITUTION:The light from a light source 1 is reflected by a printed matter 2 and the reflected light is received by a self-scanning type photoelectric con verter 3 and converted to a digital value by an A/D converter 4. This digital value is stored in image memories 5a, 5b, 5c, 5d by an address controller 10 determining a memory address on the basis of the drive pulse of the self- scanning type photoelectric converter 3 and the feed position information of the printed matter 2. Pieces of image information selected by switches 6a, 6b are compared by a comparator 7 and the max. value of comparing output is held to a peak value holding circuit 8. This comparison is performed with respect not only to the same parts of the same patterns but also to the peripher ies thereof to make it possible to minimize an error signal due to the printing elongation of the printed matter and feed position information. |
