| 摘要 |
The appts. has a circuit to generate a track jumping signal (SJJ), consisting of a driving impulse signal (SDD), followed by a braking impulse signal (SBB). Generation of this signal, which is delivered to a control signal generating circuit (22), so as to move the scanner rapidly to a desired position, depends on a tracking error signal (SE) delivered by a tracking error signal generator (11). The duration of the driving impulse signal and of the braking impulse signal are regulated by counters (26,27) connected to the input of the control signal generating circuit. Pref. a system control circuit (21) generates an initial instruction signal (SX) corresponding to the start of a search procedure, while one counter (26) generates a second instruction signal (Sy) corresponding to the end of the driving impulse signal. A signal (Sz) corresponding to the end of the braking impulse signal is generated by the second counter (27).
|
