Bi-frequency servo pattern
AssigneeSeagate Technology LLC
InventorsHuaan Zhang, Alexei Sacks
Life of this patent
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Abstract
A data storage device for retrieving data includes a controllably positionable head and a storage medium having servo information comprising a phase pattern having a first frequency and a PES pattern having a second frequency, the second frequency being different from the first frequency.
Claims14
A storage medium having servo information comprising a phase pattern having a first frequency and an associated position pattern having a second frequency, the second frequency being different from the first frequency, the position pattern being one of a set of position patterns consisting of a null-type servo pattern and a split burst amplitude pattern, the storage medium further comprising a demodulator that uses a demodulator signal that has a frequency that is based on a relationship between the first frequency and the second frequency.
A method comprising:
- recording a phase pattern having a first frequency;
- recording an associated position pattern having a second frequency, the second frequency being different from the first frequency;
- reading the position pattern to produce a position signal;
- using a relationship between the first frequency and the second frequency to generate a demodulating signal;
- and
- demodulating the position signal using the demodulating signal to produce a position error value.
A device comprising:
- a positioning block coupled to a head for receiving a phase signal generated from a phase field having a first frequency and receiving an associated position signal generated from a position field having a second frequency, the second frequency being different from the first frequency, and for using the phase signal and a relationship between the first frequency and the second frequency to produce a demodulating signal and using the demodulating signal to demodulate the position signal to generate a position error value.
Dependencies are inferred from the claim text.