Abnormal flow detecting circuit in paper sheet counting machine

Claim 1

A circuit for detecting abnormal flows in a paper sheet counting machine wherein sheets of paper which are temporarily stacked in an inlet section are drawn out through a paper sheet passage, one at a time, and are counted, which comprises; length detecting means for detecting the length of each paper sheet when said each paper sheet passes through a predetermined position of said paper sheet passage and issuing a respective length signal for the passage of said each paper sheet; memory means operatively connected to said length detecting means for storing length data obtained from each length signal; computing means operatively connected to said memory means for calculating average data of lengths of paper sheets from length data stored in said memory means, said average length data being stored in said memory means; renewal means operatively connected to said memory means and said computing means for renewing said average length data stored in said memory means by providing the newest length data from said memory means to said computing means corresponding to the passage of said each paper sheet; comparing means operatively connected to said memory means for comparing said newest length data and said average length data to generate a difference signal representative of the difference between said newest length data and said average length data; and judging means operatively connected to said comparing means for determining whether an abnormal flow of the paper sheets occurs, in response to said difference signal from said comparing means.