Abstract: United States paper currency can be denomination sensed by a system for scanning a predetermined path along one surface and comparing the resultant scan against a standard for a particular denomination. Subsequently, it is determined whether the scanned currency is of a particular denomination or is questionable. The one surface can be an obverse surface of paper currency, the predetermined path of the obverse surface can be magnetically scanned; the scanning direction occurs along a major axis of the currency; and the scanned currency can be sorted in accordance with the determination. Various denominations can be determined at one time either in seriatim or in parallel.

Abstract: A bill to be verified is scanned lengthwise by a two track optical sensor. For each bill the resulting analog signals are divided into eight segments or windows each segment producing a binary coded pattern produced by delta modulation. This is compared to a stored reference and a number is produced representing the dissimilarity between the bill being scanned and the average bill of that denomination with which it is being compared. Thereafter, a processor compares the foregoing numbers with additional quantitative functions which have previously been stored relating the corresponding segments of the bill denomination being scanned to other bill denominations. With the use of limit and weighting functions they are summed over the eight different effective windows and a decision is made as to whether the proper denomination is present.