Abstract: A document processing apparatus that detects magnetic characters on documents as they pass therethrough. The apparatus includes a transport path, pairs of wheels for driving the documents through the apparatus, a DC magnetic writing device and a magnetic reading device. The DC magnetic writing device orientates the magnetic dipoles of the characters on the documents; and the reading device detects the orientated dipoles of the characters. The writing device precedes the reading device and is provided by two magnets, one of which is located on each side of the transport path, with the magnets having like magnetic poles facing toward each other.

Abstract: An improved magnetic character recognition system employing a linearly operated dynamic or variable threshold voltage determination system and signal deterioration compensation circuits for expanding the range of dynamic information signals to which the dynamic threshold voltage determination system reliably responds to accommodate magnetically encoded characters that produce an unusually high or low strength magnetic flux for producing digital output pulses of uniform width throughout the expanded information signal range.

Abstract: A system for accurately controlling the position of documents as they are throughputted along a straight line path for purposes of MICR writing and reading thereon. Accurate control of document position along a linear path is obtained by minimizing speed variations of a throughputted document, by maintaining a throughputted document in good registration, and by holding closely proximate the throughputted document to the read or write head.

Abstract: A character recognition system utilizing precisely designed correlation network to match the voltage waveform of a character being read with the closest ideal waveform in a standard character font along with an extraneous peak detector that determines whether extraneous peaks are present in the voltage waveform and a required peak detector that determines whether a predetermined pattern of required peaks are missing from the voltage waveform for that voltage waveform to have been induced by the printed character with which it was preliminarily identified, under the control of a variable threshold controlled timing circuit for an extended dynamic range of voltage waveforms.