Patent ID: 8493070
Filing Date: 2013-07-23
Classification: G01M,G11B

Abstract:
1. A vibration characteristics measurement apparatus comprising: a signal source configured to generate a signal of a frequency higher than a vibration frequency of a slider of a hard disk drive, said signal being supplied to one of the slider and a disk of the hard disk drive; a detector configured to detect a signal output from the other of the slider and the disk and output a change in a capacitance between the slider and the disk as a voltage when the hard disk drive receives an impact, wherein the detector is a phase detector that conducts detection based on the signal output from the signal source and the signal output from the other of the slider and the disk; a band-pass filter connected to the signal source; a phase adjustment circuit that receives the signal output from the other of the slider and the disk; and an amplifier connected to the band-pass filter; wherein the phase detector detects a phase difference between an output signal of the amplifier and an output signal of the phase adjustment circuit.