| 摘要 |
PURPOSE:To attain positioning with high speed and high accuracy by arranging at least two head support mechanisms in opposite direction and using an arithmetic mean of its position error signal as a control deviation so as to position the magnetic head. CONSTITUTION:Servo magnetic heads 4, 4' and head support mechanisms 6, 6' are arranged oppositely to servo faces 1b, 1c. In position error signals E1, E2 detected by the magnetic heads 4, 4', solid lines Ex1, Ex2 and chained lines Ez1, Ez2 represent a position signal component produced by the radial displacement of servo tracks 2b, 2c and outer face displacement of the arm 7. In this case, the arithmetic means of the signals E1, E2 does not include the position error signal component due to the outer face displacement of the arm 7. In utilizing the property, the signals E1, E2 are inputted to an operating section 14 conducting the algebraic mean processing, the outputted arithmetic means is inputted to a control system 12 as the control deviation of the closed loop servo control system, and is output is inputted to an actuator 9. Through the constitution above, since the control deviation is not effected by the resonance of the outer face direction of the arm 7, no nonlinear transfer element is included in the control system. |
