PAPER CONVEYING MANAGEMENT DEVICE OF IMAGE FORMING DEVICE AND DUPLICATE FEED DISCRIMINATION METHOD

摘要

PROBLEM TO BE SOLVED: To securely discriminate presence of paper and accurately detect duplicate feed of the paper even when a gap between the papers (paper absent area) is narrowed and especially data sampling in the paper absent area is impossible due to continuous feed of the paper caused by high speed processing. SOLUTION: This device discriminates duplicate feed on the basis of previously stored paper absent position data when the paper is fed continuously one by one for image forming process. Variation in output value of a duplicate feed sensor on the basis of a gradual temperature increase of the image forming device is reflected on the previously stored paper absent position data on the basis of variation in paper present position data, and thereby gradual variation between the paper absent position data and the paper present position data can be offset for accurately discriminating the duplicate feed.