Digital data modulation system for image scanner

摘要

The modulation system has each of at least 3 successive digital data bit combinations associated with a corresponding period and phase discriminating signal, with a series of period and phase discriminating signals representing a given digital data element. Pref. each of the period and phase discriminating signals for each of the 3 successive digital data bit combinations has a short medium or long period (Ts,Tm,Tl), corresponding to a bit cell width (tb) of 1, 1.5 and 2 respectively.