| 摘要 |
PURPOSE:To shorten remarkably a follow-up time of a servo-system by increasing an unbalanced quantity of positive and negative maximum output voltage or currents for driving an actuator in proportion to a moving speed in the direction vertical to a signal track of an optical pickup. CONSTITUTION:Actuator driving force F is varied like a curve 23, and is obtained by amplifying an error signal 22. A potential phi is derived by integrating the F with respect to its relative position (x), and a crest trough 25 of potential is formed. In case when an optical pickup moves to the right, when an unbalance a state of the positive maximum value < the negative maximum value is given to the positive and negative maximum values of the driving force F, the potential phi makes a wall of potential as 26 of a broken line. The potential phi increases successively as the relative position (x) increases, therefore, the kinetic energy of the optical pickup cannot break the wall of the potential. In case when the optical pickup moves to the left, the optical pickup is led into a stable state quickly in the same way by making a wall 27 of potential as a one point chain line to the left. |
