Patent ID: 7131539

Claim:
A paper sheets corner fold detection method implemented by a paper sheets processor, the method using: a carrying-in sensor part for being started by input operation from outside to a transaction start switch part and detecting insertion of a paper sheet inserted from outside for transaction; a light sensor part for detecting light reflective characteristics or light transmissive characteristics of the paper sheet, which passes the carrying-in sensor part and is carried; and a thickness sensor part for detecting a thickness change of the paper sheet, which passes the carrying-in sensor part and is carried, the method comprising: an image processing step for image-processing a detection output value from the light sensor part by an image processing part; an image corner fold determination step for determining whether a corner fold exists or not in the front end part or the back end part of the paper sheet in the carrying direction based on image data processed by the image processing step; a thickness corner fold determination step for determining whether a corner fold exists or not in the front end part or the back end part of the paper sheet in the carrying direction based on a detection output value from the thickness sensor part; and a paper sheet corner fold determination step for determining whether a corner fold exists or not in the front end part or the back end part of the paper sheet in the carrying direction based on the image corner fold determination step and the thickness corner fold determination step; and a control step for controlling ejection carrying of the paper sheet so that the paper sheet is separately accommodated in a reusable paper sheets accommodation part, a pre-accommodation inversion part, or an unusable paper sheets accommodation part according to a region where a corner fold exists when it is confirmed that the corner fold exists in the paper sheet in the paper sheets corner fold determination step.