Abstract: A magnetic disk system utilizes both of voice coil motor and a piezoelectric element provided on a head supporting arm to precisely position a head to a predetermined position on a disk. The piezoelectric element is built in the distal end portion of the head supporting arm and is restricted in respect of its movement by a resilient mechanism which has low rigidity in the driving direction of the piezoelectric element and high rigidity in the other directions. The resilient mechanism is formed by pairs of doubled parallel leaf springs so arranged that each pair is disposed on either side of the piezoelectric element.

Abstract: A vibrating-type driving unit employing a piezo-electric device is provided for conveying an object such as a sheet material. A follower roller is provided to be opposed to the vibrating-type driving unit, and A.C. power is supplied thereto so as to convey the object. In addition, a friction coefficient of surface of the follower roller is selected to be greater than friction coefficient of a driving head of the vibrating-type driving unit. With this selection, it is possible to convey the object efficiently and stably.