Abstract: A character recognition apparatus uses a magnetic head to read magnetic printed coded characters from a passing cheque 10. A head 24 using a circuit including a delay line 58 drives a controller 76 which, should a character not instantly be recognized by matching against templates, first varies the presumed speed by plus or minus 10% to see if a match can be found, then suppresses each detected edge in the character, in turn, to determine whether or not a match can be found. Each edge is used to create subsequent timing windows wherein a subsequent edge may be detected. The use of timing windows suppresses erroneous edge detection.

Abstract: An apparatus for recognizing characters 20 on a document 10 comprises a scanning head 24 and decoding circuits 78, 72, 86, 92, 80, feeding a controller 84. The controller 84 detects the identity of the characters 20A-20N by calculating the ratio found by dividing the time between a first positive pulse 32 and a second positive pulse 34 by the time between the first positive pulse 32 and a last negative pulse 36 and comparing it against a stored table of ratios.