| 摘要 |
PURPOSE:To eliminate the need for a switching gate at a normal rotating time and a start rotating time, by a method wherein an output pulse with a pulse width of not more than a channel bit is fetched by a monostable multivibrator only at a time when a maximum inversion spacing of a reproduction signal is inputted. CONSTITUTION:A reproduction EFM signal (a) is supplied to an input terminal 10 from a compact disc 1. The signal (a) is supplied to one input terminal of an exclusive-OR 11, and meanwhile, it is fed to the other terminal of the exclusive-OR 11 via a delay circuit 12. An edge detecting pulse (b) is outputted from the exclusive-OR 11, and is inputted to a retriggerable monostable multivibrator 13. A pulse (d) with a given width appears at a Q output terminal of the retriggerable monostable multivibrator 13 only at a time when a maximum inversion spacing is inputted. After the pulse (d) is fed to a pulse - voltage converter 14 for conversion, it is fed to a differential amplifier 15, and meanwhile, it is returned to the retriggerable monostable multivibrator. |
