Harmonic measurement for head-disk spacing control using user data

A hard disk drive that determines a flying height from a ratio of a first harmonic transfer function and a third harmonic transfer function. The transfer functions can be determined from a response to an impulse function. The impulse function (also known as an impulse response) can be a playback wav...

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Bibliographic Details
Main Authors Che, Carl Xiaodong, Tang, Yawshing, Lee, Haejung
Format Patent
LanguageEnglish
Published 10.08.2010
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Summary:A hard disk drive that determines a flying height from a ratio of a first harmonic transfer function and a third harmonic transfer function. The transfer functions can be determined from a response to an impulse function. The impulse function (also known as an impulse response) can be a playback waveform de-convolved by channel data sequence. Any change in the ratio of the first and third harmonic transfer functions corresponds to a change in the flying height. The disk drive may utilize the transfer function ratios in a feedback routine to control the flying height.