| 摘要 |
A capstan servo device comprises a frequency generator (2) for detecting the rotation rate of a capstan motor (1) and generating two-phase FG signals mutually having a 90 DEG phase difference; a selector (5) for selecting one of input four-phase signals produced from the two-phase FG signals and having a mutual 90 DEG phase difference; and a sync signal generator (6) including an N-bit counter (8) (where N >/= 2) to receive a reference frequency signal inputted thereto and generating a sync signal by phase-comparing the two high-order bits of the frequency-divided output of the counter (8) with the two-phase FG signals. In this device, the rotation speed of the capstan motor (1) is controlled in accordance with an error voltage signal selected by the selector (5) in response to the sync signal. <IMAGE> |
