Print substrate e.g. paper sheet, side edge recognition method for digital printing machine, has differentiator unit and high pass filter provided for amplification or illustration of signal deviation caused by shadowing of edge

摘要

The device has light transmitter (4) in form of a light barrier, and light receiver (3) designed as a CCD line sensor. A differentiator unit and a high pass filter are provided for electronic amplification or illustration of a signal deviation caused by shadowing of an edge to be recognized. The high pass filter and a low pass filter is combined to a band pass filter. The low pass filter is provided for suppressing the noise.