JPS6437779A - Head access device - Google Patents

Abstract

PURPOSE:To execute a fine head access by using a displacement converting element to have a displacement converting characteristic to include a substantial dead band, inserting a piezoelectric actuator into a displacement transmitting route, driving and controlling this piezoelectric actuator according to the output of a first ground movement position detecting means. CONSTITUTION:The titled device is composed of a cam 52, as the displacement converting element, to have a converting characteristic to include the substantial dead band when the output displacement of a driving source 51 to give the displacement to a head carriage 54 is converted to the displacement suitable to the head carriage 54 and transmitted to a head 60, and a piezoelectric actua tor 58, which is inserted into the displacement transmitting route from the driving source 51 to the head 60 and obtains the displacement to execute opera tion with overlapping to the displacement of the head 60 by the driving source 51. Then, a first ground movement position to this piezoelectric actuator 58 is detected by a displacement detector 80. Thus, a fine tracking can be executed.