Methods for improving printed media self-servo writing
View Patent ↗Methods in accordance with the present invention can be applied to improve printed media self-servo writing by reducing PES noise and SAM error-rate at an outer diameter of a reference surface of a disk. In one such method, a template pattern having zig-bursts within a servo wedge describing radial positioning that are replaced by pulses at an inner diameter of the reference surface such that head skew at the inner diameter is a limiting factor for pattern frequency at the inner diameter, can be printed or otherwise written to a reference surface of the disk. A hard disk drive can then be assembled with the disk and a servo pattern can be written based on the template pattern for each surface of the disk. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.
1. A method to self-servo write one or more surfaces in a data storage device having a rotatable medium, comprising:
creating a template pattern on a reference surface of said rotatable medium;
connecting said rotatable medium with a spindle;
connecting the spindle with said data storage device;
connecting an actuator having one or more heads with the hard disk drive so that each of the one or more heads is positioned over a corresponding surface of said rotatable medium;
reading the template pattern with at least one of the one or more heads; and
writing a servo pattern on at least one of the surfaces of said rotatable medium based on the template pattern;
wherein the template pattern includes at least one servo wedge having a first end and a second end, each servo wedge having:
a plurality of pulses extending from the first end to the second end; and
a plurality of zig-bursts, each zig-burst forming an angle relative to the plurality of pulses; and
wherein the angle at the first end is zero and the angle at the second end is a chevron angle.
2. The method of claim 1 , wherein the at least one servo wedge extends along at least a portion of a stroke of the one or more heads; and
wherein the angle varies along at least a portion of the stroke.
3. The method of claim 1 , wherein the at least one servo wedge extends along at least a portion of a stroke of the one or more heads; and
wherein the angle abruptly changes from zero to the chevron angle at a position along the stroke.
4. The method of claim 1 , wherein each servo wedge further comprises a plurality of zag-bursts, each zag-burst forming a negative chevron angle relative to the plurality of pulses.
5. The method of claim 1 , wherein said rotatable medium is a disk.
6. The method of claim 5 , wherein the first end of the at least one servo wedge is at an inner diameter of the disk.
7. The method of claim 5 , wherein the second end of the at least one servo wedge is at an outer diameter of the disk.
8. The method of claim 1 , further comprising:
connecting one or more additional rotatable media with the spindle, each of the one or more additional rotatable media having one or more surfaces; and
writing a servo pattern on each surface of the one or more additional rotatable media based on the template pattern.
9. A method to self-servo write one or more surfaces in a data storage device having a rotatable medium, comprising:
creating a template pattern on a reference surface of said rotatable medium;
connecting said rotatable medium with a spindle;
connecting the spindle with said data storage device;
connecting an actuator having one or more heads with the hard disk drive so that each of the one or more heads is positioned over a corresponding surface of said rotatable medium;
reading the template pattern with at least one of the one or more heads; and
writing a servo pattern on at least one of the surfaces of said rotatable medium based on the template pattern;
wherein the template pattern includes at least one servo wedge having a first end and a second end, each servo wedge having:
a plurality of pulses extending from the first end to the second end; and
a plurality of zag-bursts, each zag-burst forming an angle relative to the plurality of pulses; and
wherein the angle at the first end is zero and the angle at the second end is a chevron angle.
10. The method of claim 9 , wherein the at least one servo wedge extends along at least a portion of a stroke of the one or more heads; and
wherein the angle can vary along at least a portion of the stroke.
11. The method of claim 9 , wherein the at least one servo wedge extends along at least a portion of a stroke of the one or more heads; and
wherein the angle abruptly changes from zero to the chevron angle at a position along the stroke.
12. The method of claim 9 , wherein the template pattern further comprises a plurality of zig-bursts, each zig-burst forming a negative chevron angle relative to the plurality of pulses.
13. The method of claim 9 , wherein said rotatable medium is a disk.
14. The method of claim 13 , wherein the first end of the at least one servo wedge is at an inner diameter of the disk.
15. The method of claim 13 , wherein the second end of the at least one servo wedge is at an outer diameter of the disk.
16. The method of claim 9 , further comprising:
connecting one or more additional rotatable media with the spindle, each of the one or more additional rotatable media having one or more surfaces; and
writing a servo pattern on each surface of the one or more additional rotatable media based on the template pattern.
17. A method to self-servo write one or more surfaces of a disk for storing data in a hard disk drive, comprising:
printing a template pattern on a reference surface of said disk;
connecting said disk with a spindle;
connecting the spindle with said hard disk drive;
connecting a rotary actuator having one or more heads with said hard disk drive such that each of the one or more heads is positioned over a corresponding surface of the disk;
reading the template pattern with at least one of the one or more heads; and
writing a servo pattern on at least one of the surfaces of the disk based on the template pattern;
wherein the template pattern includes at least one servo wedge having a first end and a second end, each servo wedge having:
a plurality of pulses extending from the first end to the second end; and
a plurality of zig-bursts, each zig-burst forming an angle relative to the plurality of pulses; and
wherein the angle at the first end is zero and the angle at the second end is a chevron angle.
18. The method of claim 17 , wherein the at least one servo wedge extends along at least a portion of a stroke of the one or more heads; and
wherein the angle can vary along at least a portion of the stroke.
19. The method of claim 17 , wherein the at least one servo wedge extends along at least a portion of a stroke of the one or more heads; and
wherein the angle abruptly changes from zero to the chevron angle at a position along the stroke.
20. The method of claim 17 , wherein each servo wedge further comprises a plurality of zag-bursts, each zag-burst forming a negative chevron angle relative to the plurality of pulses.
21. The method of claim 17 , wherein the first end of the at least one servo wedge is at an inner diameter of the disk.
22. The method of claim 17 , wherein the second end of the at least one servo wedge is at an outer diameter of the disk.
23. The method of claim 17 , further comprising:
connecting one or more blank disks with the spindle, each of the one or more blank disks having one or more surfaces; and
writing a servo pattern on each surface of the one or more blank disks based on the template pattern.
24. A method to self-servo write one or more surfaces of a disk for storing data in a hard disk drive, comprising:
printing a template pattern on a reference surface of said disk;
connecting said disk with a spindle;
connecting the spindle with said hard disk drive;
connecting a rotary actuator having one or more heads with said hard disk drive such that each of the one or more heads is positioned over a corresponding surface of the disk;
reading the template pattern with at least one of the one or more heads; and
writing a servo pattern on at least one of the surfaces of the disk based on the template pattern;
wherein the template pattern includes at least one servo wedge having a first end and a second end, each servo wedge having:
a plurality of pulses extending from the first end to the second end; and
a plurality of zag-bursts, each zag-burst forming an angle relative to the plurality of pulses; and
wherein the angle at the first end is zero and the angle at the second end is a chevron angle.
25. The method of claim 24 , wherein the at least one servo wedge extends along at least a portion of a stroke of the one or more heads; and
wherein the angle can vary along at least a portion of the stroke.
26. The method of claim 24 , wherein the template pattern further comprises a plurality of zig-bursts, each zig-burst forming a negative chevron angle relative to the plurality of pulses.
27. The method of claim 24 , wherein the first end of the at least one servo wedge is at an inner diameter of the disk.
28. The method of claim 24 , wherein the second end of the at least one servo wedge is at an outer diameter of the disk.
29. The method of claim 24 , further comprising:
connecting one or more blank disks with the spindle, each of the one or more blank disks having one or more surfaces; and
writing a servo pattern on each surface of the one or more blank disks based on the template pattern.
30. A method to self-servo write one or more surfaces of a disk for storing data in a hard disk drive, comprising:
printing a template pattern on a reference surface of said disk;
connecting said disk with a spindle;
connecting the spindle with said hard disk drive;
connecting a rotary actuator having one or more heads with said hard disk drive such that each of the one or more heads is positioned over a corresponding surface of the disk, the one or more heads having a range of motion of a stroke;
reading the template pattern with at least one of the one or more heads; and
writing a servo pattern on at least one of the surfaces of the disk based on the template pattern;
wherein the template pattern includes at least one servo wedge, each servo wedge having:
a plurality of pulses, each pulse extending from an inner diameter of said disk along at least a portion of the stroke; and
a plurality of zig-bursts;
a plurality of zag-bursts;
wherein each of one of the plurality of zig-bursts and the plurality of zag-bursts forms a variable angle relative to the plurality of pulses; and
wherein the variable angle at the inner diameter is zero; and
wherein the variable angle varies across at least a portion of the stroke.
31. The method of claim 30 , wherein the variable angle increases across at least a portion of the stroke starting from an inner diameter of said disk.
32. The method of claim 30 , wherein the variable angle increases from an inner diameter according to the equation
θ
x
=
cos
-
1
[
R
ID
R
x
cos
(
θ
s
)
]
-
θ
s
.
33. A method to manufacture a reference surface for self-servo writing one or more surfaces of one or more rotatable media in a data storage device, comprising:
selecting a transfer medium having a template pattern, the template pattern including at least one servo wedge having a first end and a second end, each servo wedge having:
a plurality of pulses extending from the first end to the second end; and
a plurality of zig-bursts, each zig-burst forming an angle relative to the plurality of pulses; and
wherein the angle is zero at the first end and a chevron angle at the second end; and
selecting a master disk having one or more surfaces;
transferring the template pattern to one of the one or more surfaces of the master disk.
34. The method of claim 33 , wherein the angle varies between the first end and the second end.
35. The method of claim 33 , wherein the transfer medium is a reticle.
36. The method of claim 33 , wherein the transfer medium is a die.
37. The method of claim 33 , wherein the transfer medium is a disk.
38. A method to manufacture a reference surface for self-servo writing one or more surfaces of one or more rotatable media in a data storage device, comprising:
selecting a transfer medium having a template pattern, the template pattern including at least one servo wedge having a first end and a second end, each servo wedge having:
a plurality of pulses extending from the first end to the second end; and
a plurality of zag-bursts, each zag-burst forming an angle relative to the plurality of pulses; and
wherein the angle is zero at the first end and a chevron angle at the second end; and
selecting a master disk having one or more surfaces;
transferring the template pattern to one of the one or more surfaces of the master disk.
39. The method of claim 38 , wherein the angle varies between the first end and the second end.
40. The method of claim 38 , wherein the transfer medium is a reticle.
41. The method of claim 38 , wherein the transfer medium is a die.
42. The method of claim 38 , wherein the transfer medium is a disk.
43. A method to manufacture a template pattern, comprising:
forming at least one servo wedge having a first end and a second end, each servo wedge having:
a plurality of pulses extending from the first end to the second end; and
one or both of a plurality of zig-bursts and a plurality of zag-bursts;
wherein each of one of the zig-bursts and the zag-bursts forms an angle relative to the plurality of pulses; and
wherein the angle is zero at the first end and a chevron angle at the second end.
44. The method of claim 43 , wherein the angle varies between the first end and the second end.