Abstract
This paper reports on the measurement method of vibrations in Hard Disk Drives(HDD) by using Laser Doppler Vibrometers (LDV).In HDD,the flying height of a magnetic head needs to be reduced for high recording density.Flying stability is needed to prevent contact between the head and disk.Furthermore,the magnetic track width also needs to be narrow for high recording density.The Dual Stage Actuator(DSA) servo system is currently being used for high positioning accuracy.In the DSA servo system,a piezoelectric actuator on a suspension is used to actuate the head.In this study,the vibrations of the head and suspension were measured during the PZT actuation and voice coil motor(VCM) actuation. Based on the results,we considered the influences of vibrations for the flying height stability.