Method and apparatus for registering overlapping printed images

摘要

Method and apparatus are disclosed for indicating and correcting misregister of plural overlapping images produced by a multicolor press. A register indicia (FIG. 3) is used comprising two overlapping sets of parallel lines (R and C), each set being formed in a known position relative to a corresponding one of the images whereby the positional relationship between the sets of lines varies with the positional relationship of the images. The extent of overlap of the sets of lines is dependent upon displacement of the sets of lines in a direction transverse to the lines, whereby the percentage of nonprint area in the register indicia is dependent upon register of the overlapping images in that transverse direction. The percentage of nonprint area is detected by illuminating the register indicia area and measuring the extent to which the area reflects the light. The resulting signal is used to control the register adjustment mechanisms of the multicolor press.