Apparatus for reading patterns

摘要

The present invention is directed to improvements in an automatic pattern reading apparatus of the type which comprises a light source for illuminating an object pattern, an imaging unit for receiving the illumination light reflected by or transmitted through the object pattern and a drive unit for one- or two-dimensionally moving said object pattern or said imaging unit. The improvement comprises means for detecting the leading edge position of said object pattern by means of the output picture signal from said imaging unit, means for detecting the trailing edge position of said object pattern, area detection means for detecting an area including the area defined by the leading and trailing edge positions and the area surrounding said defined area and characteristic extract means for extracting the characteristic amount of said object pattern by means of picture signal derived from the detected area.