To provide a paper crease detection device and method capable of recognizing paper crease and missing of a corner of the paper with high accuracy.

A light emission part is arranged above a passing part of a left end of the paper, a light-receiving part is arranged below the passing part of the left end of the paper, a light emission part is arranged above a passing part of a right end of the paper, and a light-receiving part is arranged below the passing part of the right end of the paper. The light emitted from the left end light emission part is received by the left end light-receiving part, and the left end light-receiving part outputs a received light amount to a paper crease detection part. Similarly, the light emitted from the right end light emission part is received by the right end light-receiving part, and the right end light-receiving part outputs a received light amount to the paper crease detection part. The paper crease detection part detects the paper crease based on the light amount input from the left end light-receiving part and the light amount input from the right end light-receiving part.

COPYRIGHT: (C)2008,JPO&INPIT