| 摘要 |
PURPOSE:To realize highly accurate high speed positioning by setting the parameters of trapezoidal driving current individually according to the difference between a target speed and an actual moving speed of each head. CONSTITUTION:Upon receiving a trapezoidal signal 7 corresponding to the seek length from a microprocessor(MPU) 1, a trapezoidal driving current generating circuit 2 generates a driving current 8 which is then fed to a power amplifier 3. A voice coil motor driving current 9 is fed to a motor 7 and a magnetic head 16 is sought at a target track. A position signal modulation circuit 5 then modulates a position signal 11 from position information 10 and a track traverse pulse generating circuit 6 creates a track traverse pulse 12. The variation time is then measured and an actual head moving speed is determined and then the difference from a target head moving speed is detected. Parameters are set individually so that the duration of flat part of the driving current 8, inclination thereof and the time required to reach the flat part are varied and the difference of head moving speed is eliminated thus removing influence of external force. |
