Systems for variable multi-pass servowriting and self-servowriting
View Patent ↗The amount of position error written into a servo burst pattern can be reduced by using additional media revolutions to write the pattern. Where the edges of two servo bursts are used to define a position on the media, trimming the first burst and writing the second burst on separate revolutions will result in a different amount of position error being written into each burst. The end result will be a reduction in the overall error in position information. In order to further reduce the position error given by a burst pair, each burst also can be trimmed and/or written in multiple passes. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.
1. A system for writing position information to a rotating medium, comprising:
a rotatable medium capable of storing information written to the rotatable medium, the rotatable medium having an inner diameter and an outer diameter;
a write element capable of writing information to the rotatable medium; and
a control mechanism adapted to rotate the rotatable medium and position the write element relative to the rotatable medium, such that the write element can:
write at least a portion of a first servo burst during a first pass of a write element over a rotating medium;
trim at least a portion of a first servo burst during a second pass of the write element; and
write at least a portion of a second servo burst during one of the second pass and a third pass of the write element, wherein one of the second and the third pass used to write at least a portion of the second servo burst being determined by the location of the second servo burst relative to at least one of the inner diameter and outer diameter.
2. A system according to claim 1 , wherein:
at least a portion of a second servo burst is written on the third pass only if the second burst defines a data track centerline.
3. A system according to claim 1 , wherein:
the number of portions used to write the second burst increases toward the outer diameter.
4. A system according to claim 1 , wherein:
the rotatable medium is selected from the group consisting of magnetic disks, optical disks, and laser-recordable disks.
5. A system according to claim 1 , wherein:
each of the first portion and second portion comprises a servo burst.
6. A system according to claim 1 , further comprising:
a read element adapted to read the first servo burst and second servo burst on a subsequent pass over the rotatable medium.
7. A system according to claim 6 , further comprising:
a read/write head containing the read element and the write element.
8. A system according to claim 7 , further comprising:
read circuitry adapted to accept information from the read element and determine the position of the read/write head.
9. A system according to claim 1 , wherein:
the write element is further capable of trimming a portion of the first servo burst such that the first servo burst has a width approximately equal to the width of a track of servo data.
10. A system according to claim 1 , wherein:
the write element is further capable of writing the first and second servo bursts in a servo wedge on the rotatable storage medium.
11. A system according to claim 1 , wherein:
the write element is further capable of trimming a edge of the first servo burst and writing an adjacent edge of the second servo burst in order to define the position of a centerline of a data track on the rotatable storage medium.
12. A system according to claim 1 , wherein:
the write element writes at least a portion of the second servo burst before trimming at least a portion of the first servo burst.
13. A system for writing position information to a rotating medium, comprising:
a rotatable medium capable of storing information written to the rotatable medium, the rotatable medium having an inner diameter and an outer diameter;
a write element capable of writing information to the rotatable medium; and
a control mechanism adapted to rotate the rotatable medium and position the write element relative to the rotatable medium, such that the write element can:
write a plurality of servo tracks to a rotatable storage medium, wherein the position of each servo track is defined by an edge of a first servo burst and a complimentary edge of a second burst, and wherein the first servo burst is written in a first revolution of the rotatable storage medium, and the first burst is trimmed on a second revolution, the second servo burst also being written on the second revolution; and
write a plurality of data tracks to a rotatable storage medium, wherein the position of each data track is defined by an edge of a third servo burst and a complimentary edge of a fourth servo burst, and wherein the third servo burst is written in a third revolution of the rotatable storage medium, the third servo burst is trimmed in a fourth revolution, and at least a portion of the fourth servo burst is written in one of the fourth revolution or a subsequent revolution, the pass used to write at least a portion of the fourth servo burst being determined by the location of the fourth servo burst relative to at least one of the inner diameter and outer diameter.
14. A system for writing position information to a rotating medium, comprising:
a rotatable medium capable of storing information written to the rotatable medium, the rotatable medium having an inner diameter and an outer diameter;
a write element capable of writing information to the rotatable medium; and
a control mechanism adapted to rotate the rotatable medium and position the write element relative to the rotatable medium, such that the write element can:
write a plurality of servo tracks to a rotatable storage medium, wherein the position of each servo track is defined by an edge of a first servo burst and a complimentary edge of a second burst, and wherein the first servo burst is written in a first revolution of the rotatable storage medium, and at least a portion of the first burst is trimmed on a second revolution, the second servo burst being written in one of the second revolution or a subsequent revolution, the pass used to write at least a portion of the second servo burst being determined by the location of the second servo burst relative to at least one of the inner diameter and outer diameter; and
write a plurality of data tracks to a rotatable storage medium, wherein the position of each data track is defined by an edge of a third servo burst and a complimentary edge of a fourth servo burst, and wherein the third servo burst is written in a third revolution of the rotatable storage medium, the third servo burst is trimmed in a fourth revolution, and at least a portion of the fourth servo burst is written in one of the fourth revolution or a subsequent revolution, the pass used to write at least a portion of the fourth servo burst being determined by the location of the fourth servo burst relative to at least one of the inner diameter and outer diameter.
15. A system for writing position information to a magnetic hard disk, comprising:
means for writing at least a portion of a first servo burst during a first pass of a write element over a rotating medium;
means for trimming at least a portion of a first servo burst during a second pass of the write element; and
means for writing at least a portion of a second servo burst during one of the second pass and a third pass of the write element, wherein one of the second and the third pass used to write at least a portion of the second servo burst being determined by the location of the second servo burst relative to at least one of the inner diameter and outer diameter.