Automatic pattern reading appts. - has image pick=up element and object pattern leading and trailing edge detectors

摘要

The automatic pattern reading appts. 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 the object pattern or the imaging unit. The appts. also includes circuits for detecting the leading edge position of the object pattern by means of the output picture signal from the imaging unit, and for detecting the trailing edge position of the object pattern. An area detector is provided for detecting an area including the area defined by the leading and trailing edge positions and the area surrounding the defined area. A characteristic extract circuit is also provided for extracting the characteristic amount of the object pattern by means of picture signal derived from the detected area.