A MICR waveform analyzer for reading E-13B magnetic ink characters including a digital phase lock loop to locate the character, a Normalizer to compress data and equalize ink strength dynamic range, and a waveform amplitude analyzer to identify the magnetically read character is described....http://www.google.co.uk/patents/US4245211?utm_source=gb-gplus-sharePatent US4245211 - MICR Waveform analyzer
