| 摘要 |
<p>PURPOSE:To eliminate an analog filter for a servo control signal processing by restoring digiatally pilot signals superposed in a digital modulation signal. CONSTITUTION:A modulation signal reproduced with a head is inputted to an A/D converter 109 via an integration equalizer 107 and an AGC 108 to be quantized into the signal, for example, having 6 bits and the quantized signal is outputted to a terminal 115 as video data having 24 bit per a word via a viterbi decoder 110 and a digital reproducing signal processing circuit 114. An ATF detection circuit 130 is provided with detection circuits 112, 113 corresponding respectively to the first and second pilot signals f1, f2 superposed in the digital modulation signal and detects and extracts pilot signals f1, f2 from the reproducing modulation signal quantized into as 6 bits from the A/D converter 109 to transmit them to an MPU 140 as signals of a tracking control and a capstan control. Further, detection circuits 112, 113 are constituted of digital circuits such as a digital band-pass filter and a decimate circuit, etc.</p> |
