| 摘要 |
PURPOSE:To obtain a stable transient response regardless of the numbers of moving tracks, by changing the acceleration and deceleration in response to the accelerating and decelerating region of a moving position model, corresponding to the number of moved tracks. CONSTITUTION:The number of tracks from the track where a transducer head (e.g., magnetic head) is positioned at present to a track desired to be moved in future, is inputted to an acceleration and deceleration selecting loop 2 and a moving position model calculating loop 3. The optimum acceleration determined depending on the track number is calculated at the acceleration and deceleration selection loop 2, and it is fed to the moving position model calculating loop 3. A feedforward signal determined on the signal value applied to a feedforward signal calculating loop 4 is applied from the calculating loop 3, and a signal corresponding to the sum of the feedforward signal is applied from a power amplifier 12 to a voice coil motor 8 to drive it. Since this driving signal includes the optimum acceleration determined depending on the number of moved tracks, the transient response from the movement with less number of moved tracks to that with many moved tracks is made stable, and the positioning is attained in the possible shortest time regardless of the number of moved tracks. |
