Method and apparatus for currency discrimination and counting

An improved method for discriminating between currency bills of different denominations, each currency bill having printed indicia enclosed within a borderline defined thereupon so that the bill surface outside the borderline is substantially blank, comprising the steps of:

• illuminating a predetermined section of a currency bill by focusing at least one strip of coherent light thereupon;
• detecting the light reflected off said illuminated section of said bill to generate an analog reflectance signal;
• generating relative lateral displacement between said strip of coherent light and said currency bill so as to illuminate or optically scan successive sections of said bill along a predetermined dimension thereof and enclosed within said borderline;
• obtaining a series of analog reflectance signals corresponding to light reflected from each of said successive bill sections using a first relatively narrow strip of coherent light to detect said borderline as the, currency bill moves across said strip by detecting the difference in magnitude of the reflectance signal obtained from the bill surface outside said borderline and the reflectance signal obtained about said borderline itself, and using a second relatively wide strip of coherent light to obtain said reflectance signals representing said characteristic patterns after said borderline has been detected;
• digitizing and processing said series of analog reflectance signals to yield a set of digital data samples which, in combination, represent a data pattern characteristic of the currency denomination of said bill;
• generating and storing a set of master characteristic patterns corresponding to optical scanning of original bills of each of the different currency denominations to be discriminated;
• and
• comparing the characteristic pattern for a scanned currency bill to each of said stored master patterns to determine the degree of correlation therebetween, and thereby to identify the denomination of said currency bill

An improved method for discriminating between currency bills of different denominations comprising the steps of:

• illuminating a predetermined section of a currency bill by focusing at least one strip of coherent light thereupon;
• detecting the light reflected off said illuminated section of said bill to generate an analog reflectance signal;
• generating relative lateral displacement between said strip of coherent light and said currency bill so as to illuminate or optically scan successive sections of said bill along a predetermined dimension thereof;
• obtaining a series of analog reflectance signals corresponding to light reflected from each of said successive bill sections;
• digitizing and processing said series of analog reflectance signals to yield a set of digital data samples which, in combination, represent a data pattern characteristic of the currency denomination of said bill;
• generating and storing a set of master characteristic patterns corresponding to optical scanning of original bills of each of the different currency denominations to be discriminated;
• comparing the characteristic pattern for a scanned currency bill to each of said stored master patterns to determine the degree of correlation therebetween, and thereby to identify the denomination of said currency bill;
• and
• positively identifying said scanned bill as having the denomination corresponding to the stored master pattern for which the degree of correlation is found to be the highest and at least equal to a predefined correlation threshold.

Improved apparatus for discriminating and counting currency bills of different denominations comprising:

• an input path for receiving currency bills to be discriminated and along which bills may be moved along a first direction;
• an output path along which bills may be moved along a second direction;
• a curved guideway disposed between said input and output paths and for accepting bills from said input path and guiding them along said second direction onto said output path;
• and
• currency discrimination means located downstream of said curved guideway along said output path where said bills are guided in a substantially straight manner.