Interleaved servo patterns in a data storage device
AssigneeWestern Digital Technologies, Inc.
InventorsGuoxiao Guo, Scott A. Ottele, Richard Conway, Joey M. Poss, Gary Herbst
Life of this patent
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Abstract
Example control circuitry, data storage devices, and methods for parallel self-servo writing of interleaved servo patterns in a data storage device are described. The data storage device may include multiple heads actuated over different surfaces of a data storage device and receive read signals from two different heads over two different surfaces in parallel. The servo wedges of the two surfaces may be offset to enable independent determination of phase while writing servo patterns in parallel to the two surfaces using their respective heads.
Claims20
A data storage device, comprising:
- a first storage medium surface comprising a first servo pattern;
- and
- a second storage medium surface comprising a second servo pattern, wherein:
- the first servo pattern and the second servo pattern were written in parallel to define corresponding portions of the first servo pattern and the second servo pattern;
- a first servo pattern phase of a portion of the first servo pattern is different than a second servo pattern phase of the corresponding portion of the second servo pattern;
- the first servo pattern phase corresponds to a first data frequency offset within servo wedges in the first servo pattern;
- and
- the second servo pattern phase corresponds to a second data frequency offset within servo wedges in the second servo pattern.
A method comprising:
- positioning, in a data storage device, a first head over a first storage medium surface using a first servo pattern;
- executing, at a first target position based on the first servo pattern, a first storage operation using the first head and the first storage medium surface;
- positioning, in the data storage device, a second head over a second storage medium surface using a second servo pattern, wherein:
- the first servo pattern and the second servo pattern were written in parallel to define corresponding portions of the first servo pattern and the second servo pattern;
- a first servo pattern phase of a portion of the first servo pattern is different than a second servo pattern phase of the corresponding portion of the second servo pattern;
- the first servo pattern phase corresponds to a first data frequency offset within servo wedges in the first servo pattern;
- and
- the second servo pattern phase corresponds to a second data frequency offset within servo wedges in the second servo pattern;
- and
- executing, at a second target position based on the second servo pattern, a second storage operation using the second head and the second storage medium surface.
A data storage device comprising:
- a first head actuated over a first storage medium surface;
- a second head actuated over a second storage medium surface;
- means for determining a first servo pattern phase;
- means for writing, using the first head and to the first storage medium surface, a servo pattern segment for a servo wedge of a first servo pattern using the first servo pattern phase;
- means for determining a second servo pattern phase;
- and
- means for writing, using the second head and to the second storage medium surface, a servo pattern segment for a servo wedge of a second servo pattern using the second servo pattern phase and responsive to waiting an offset time from the first servo pattern, wherein:
- the first servo pattern and the second servo pattern are written in parallel to define corresponding portions of the first servo pattern and the second servo pattern;
- and
- the first servo pattern phase of a portion of the first servo pattern is different than the second servo pattern phase of the corresponding portion of the second servo pattern.
Dependencies are inferred from the claim text.