Dynamic stroke optimization in the self servo-write process
View Patent ↗Systems and data storage devices in accordance with embodiments of the present invention can execute instructions to determine a width of a data stroke along a rotatable medium. In one embodiment, the width can be determined by measuring a distance from a marker zone edge of a template pattern on the rotatable medium to a ramp positioned adjacent to the rotatable medium or near the inner diameter of the rotatable medium, and measuring a distance from the marker zone edge to a crash stop. A track layout can be determined based on the width of the data stroke.
1. A data storage device, comprising:
a housing;
a rotatable medium connected with the housing, said rotatable medium including a template pattern having a marker zone;
an actuator rotatably connected with the housing;
a head operably connected with the actuator, the head being adapted to access the rotatable medium;
a ramp associated with the housing, ramp being adapted to remove the head from accessing the rotatable medium;
a crash stop associated with the housing;
a machine readable medium having instructions to:
determine a location of a marker zone edge of the template pattern;
determine a location of the ramp relative to the marker zone edge;
determine a location of the crash stop relative to the marker zone edge;
calculate a width of a data stroke based on the location of the ramp and the location of the crash stop;
compare the width of the data stroke to one or more criteria; and
a processor adapted to execute the instructions.
2. The data storage device of claim 1 , wherein the instructions to determine a location of said ramp relative to said marker zone edge include instructions to:
position said head over said marker zone edge;
read said template pattern with said head;
measure a metric while reading said template pattern with said head;
adjust said actuator such that said head moves toward an outer edge of said rotatable medium; and
detect a severe change in the metric.
3. The data storage device of claim 1 , wherein the instructions to determine a location of said ramp relative to said marker zone edge include instructions to:
position said head over said marker zone edge;
read said template pattern with said head;
measure a metric while reading said template pattern with said head;
adjust said actuator such that said head moves toward an inner diameter of said rotatable medium;
detect a severe change in the metric.
4. The data storage device of claim 2 , wherein the metric is a bias force.
5. The data storage device of claim 2 , wherein the metric is an AGC level.
6. The data storage device of claim 4 , wherein the severe change is a severe drop.
7. The data storage device of claim 5 , wherein the severe change is a sharp rise.
8. The data storage device of claim 6 , wherein the severe change is a sharp rise.
9. the data storage device of claim 1 , wherein the instructions to determine a location of said crash stop relative to said marker zone edge include instructions to:
position said head river said marker zone edge;
read said template pattern with said head;
measure a metric while reading said template pattern with said head;
adjust said actuator such that said head moves toward an inner diameter of said rotatable medium; and
detect a severe change in the metric.
10. The data storage device of claim 1 , wherein the instructions to determine a location of said crash stop relative to said marker zone edge include instructions to:
position said head over said marker zone edge;
read said template pattern with said head;
measure a metric while reading said template pattern with said head;
adjust said actuator such that said head moves toward an outer edge of said rotatable medium; and
detect a severe change in the metric.
11. The data storage device of claim 9 , wherein the metric is a bias force.
12. The data storage device of claim 11 , wherein the severe change is a sharp rise.
13. The data storage device of claim 11 , wherein the severe change is a severe drop.
14. The data storage device of claim 1 , wherein the instructions to calculate the width of said data stroke based on the location of said ramp and the location of said crash stop include instructions to:
determine one or more portions of the data stroke within one or more radial zones;
weigh the one or more portions by circumferential density; and
sum the weighted one or more portions.
15. The data storage device of claim 1 , wherein the criterion is one of maximum track capacity and minimum track density.
16. A data storage device, comprising:
a housing;
a rotatable medium connected with the housing, said rotatable medium including a template pattern having a marker zone;
an actuator rotatably connected with the housing;
a head operably connected with the actuator the head being adapted to access the rotatable medium;
a ramp associated with the housing, the ramp being adapted to remove the head from accessing the rotatable medium;
a crash stop associated with the housing;
a machine readable medium having instructions to:
determine, a location of a marker zone edge of said template pattern;
determine a location of the ramp relative to the marker zone edge;
determine a location of the crash stop relative to the marker zone edge;
calculate a width of a data stroke based on the location of the ramp and the location of the crash stop;
write a final servo pattern on the rotatable medium based on the width; and
a processor adapted to execute the instructions.
17. The data storage device of claim 16 , wherein the instructions to determine a location of said crash stop relative to said marker zone edge include instructions to:
position said head over said marker zone edge;
read said template pattern with said head;
measure a metric while reading said template pattern with said head;
adjust said actuator such that said head moves toward an inner diameter of said rotatable medium; and
detect a severe change in the metric.
18. The data storage device of claim 16 , wherein the instructions to determine a location of said ramp relative to said marker zone edge include instructions to:
position said head over said marker zone edge;
read said template pattern with said head;
measure a metric while reading said template pattern with said head;
adjust said actuator such that said head moves toward an inner diameter of said rotatable medium; and
detect a severe change in the metric.
19. The data storage device of claim 17 , wherein the metric is a bias force.
20. The data storage device of claim 17 , wherein the metric is an AGC level.
21. The data storage device of claim 19 , wherein the severe change is a severe drop.
22. The data storage device of claim 19 , wherein the severe change is a sharp rise.
23. The data storage device of claim 20 , wherein the severe change is a sharp rise.
24. The data storage device of claim 16 , wherein the instructions to determine a location of said crash stop relative to said marker zone edge include instructions to:
position said head over said marker zone edge;
read said template pattern with said head;
measure a metric while reading said template pattern with said head;
adjust said actuator such that said head moves toward an outer edge of said rotatable medium; and
detect a severe change in the metric.
25. The data storage device of claim 16 , wherein the instructions to determine a location of said crash stop relative to said marker zone edge include instructions to:
position said head over said marker zone edge;
read said template pattern with said head;
measure a metric while reading said template pattern with said head;
adjust said actuator such that said head moves toward an inner diameter of said rotatable medium; and
detect a severe change in the metric.
26. The data storage device of claim 24 , wherein the metric is a bias force.
27. The data storage device of claim 26 , wherein the severe change is a sharp rise.
28. The data storage device of claim 26 , wherein the severe change is a severe drop.
29. The data storage device of claim 16 , wherein the instructions to calculate the width based on the location of said ramp and the location of the inner diameter include instructions to:
determine one or more portions of the data stroke within one or more radial zones;
weigh the one or more portions by circumferential density; and
sum the weighted one or more portions.
30. The data storage device of claim 16 , wherein the instructions to write the final servo pattern on said rotatable medium based on the width include instructions to:
select a track density;
select a capacity; and
determine a first user track and a final user track based on the track density and the capacity;
wherein a distance between said ramp and the first user track is at least a minimum outer guard band and a distance between said crash stop and the final user track is at least a minimum inner guard band.
31. The data storage device of claim 16 , wherein the instructions to write the final servo pattern on said rotatable medium based on the width includes instructions to:
select an outer guard band;
select an inner guard band;
select a capacity; and
determine a track density based on the capacity the outer guard band, the inner guard band, and the width.
32. The data storage device of claim 16 , wherein the instructions to write the final servo pattern on said rotatable medium based on the width includes instructions to:
select an outer guard band;
select an inner guard band;
select a track density; and
determine a capacity based on the track density, the outer guard band, the inner guard band, and the width.
33. The data storage device of claim 16 , wherein the instructions to determine a location of said ramp relative to said marker zone edge include instructions to:
locate said marker zone edge using said head;
move said actuator such that said head moves toward an outer edge of said rotatable medium;
measure a plurality of cycles as said head moves from the marker zone edge toward the outer edge of said rotatable medium; and
determine a position of said ramp by detecting a severe change in the metric.
34. The data storage device of claim 16 , wherein the instructions to determine a location of said crash stop relative to said marker zone edge include instructions to:
locate said marker zone edge using said head;
move said actuator such that said head moves toward an inner diameter of said rotatable medium;
measure a plurality of cycles as said head moves from said marker zone edge toward the inner diameter of said rotatable medium; and
determine a position of said crash stop by detecting a severe change in the metric.
35. The data storage device of claim 33 , wherein the metric is a bias force.
36. The data storage device of claim 33 , wherein the metric is an AGC level.
37. The data storage device of claim 35 , wherein the severe change is a severe drop.
38. The data storage device of claim 35 , Wherein the severe change is a sharp rise.
39. The data storage device of claim 36 , wherein the severe change is a sharp rise.
40. The data storage device of claim 16 , wherein said template pattern is one of a media written pattern and a printed media pattern.
41. The data storage device of claim 30 , wherein the instructions to write said final servo pattern on said rotatable medium based on the width further includes instructions to write a set of tracks from the first user track to the final user track.
42. The data storage device of claim 31 , wherein the instructions to write said final servo pattern on said rotatable medium based on the width further includes instructions to write a set of tracks between said inner guard band and said outer guard band.
43. The data storage device of claim 32 , wherein the instructions to write said final servo pattern on said rotatable medium based on the width further includes instructions to write a set of tracks between said inner guard band and said outer guard band.
44. A data storage device, comprising:
a rotatable medium having a template pattern;
a ramp;
a crash stop;
a machine readable medium having instructions to:
determine a location of a marker zone edge of said template pattern;
determine a location of said ramp relative to said marker zone edge;
determine a location of said crash stop relative to said marker zone edge; and
calculate a width of a data stroke based on the location of said ramp and the location of said crash stop; and
write a final servo pattern on the rotatable medium based on the width of the data stroke; and
a processor adapted to execute the instructions.
45. The data storage device of claim 44 , further comprising:
an actuator;
a head connected with said actuator;
wherein the instructions to determine a location of said ramp relative to said marker zone edge include instructions to:
position said head over said marker zone edge;
read said template pattern with said head;
measure a metric while reading said template pattern with said head;
adjust said actuator such that said head moves toward said ramp across said rotatable medium; and
detect a severe change in the metric.
46. The data storage device of claim 45 , wherein the metric is one of a bias force and an AGC level.
47. The data storage device of claim 44 , further comprising:
an actuator;
a head connected with said actuator;
wherein the instructions to determine a location of said crash stop relative to said marker zone edge include instructions to:
position said head over said marker zone edge;
read said template pattern with said head;
measure a metric while reading said template pattern with said head;
adjust said actuator such that said head moves toward said crash stop across said rotatable medium; and
detect a severe change in the metric.
48. The data storage device of claim 45 , wherein the metric is a bias force.
49. The data storage device of claim 44 , wherein the instructions to write a final servo pattern on the rotatable medium based on the width; include instructions to:
select a track density;
select a capacity; and
determine a first user track and a final user track based on the track density and the capacity;
wherein a distance between said ramp and the first user track is at least a minimum outer guard band and a distance between said crash stop and the final user track is at least a minimum inner guard band.
50. The data storage device of claim 44 , wherein the instructions to write a final servo pattern on the rotatable medium based on the width; include instructions to:
select an outer guard band;
select an inner guard band;
select a capacity; and
determine a track density based on the capacity, the outer guard band the inner guard band, and the width.
51. The data storage device of claim 44 , wherein the instructions to write a final servo pattern on the rotatable medium based on the width; include instructions to:
select an outer guard band;
select an inner guard band;
select a track density; and
determine a capacity based on the track density, the outer guard band, the inner guard band, and the width.
52. A system to write a final servo pattern on a rotatable medium of a data storage device, the data storage device having an actuator, a head connected with the actuator, a ramp and a crash stop, and the rotatable medium having a template pattern, the system comprising:
a machine readable medium having instructions to:
wherein the instructions to determine a width of a data stroke include instructions to:
determine a location of a marker zone edge of said template pattern;
determine a location of said ramp relative to said marker zone edge;
determine a location of said crash stop relative to said marker zone edge; and
calculate a width of a data stroke based on the location of said ramp and the location of said crash stop; and
write a final servo pattern on the rotatable medium based on the width of the data stroke.
53. The system of claim 52 , further comprising:
wherein the instructions to determine a location of said ramp relative to said marker zone edge include instructions to:
position said head over said marker zone edge;
read said template pattern with said head;
measure a metric while reading said template pattern with said head;
adjust said actuator such that said head moves toward said ramp across said rotatable medium; and
detect a severe change in the metric.
54. The system of claim 53 , wherein the metric is one of a bias force and an AGC level.
55. The system of claim 52 , further comprising:
wherein the instructions to determine a location of said crash stop relative to said marker zone edge include instructions to:
position said head over said marker zone edge;
read said template pattern with said head;
measure a metric while reading said template pattern with said head;
adjust said actuator such that said head moves toward said crash stop across said rotatable medium; and
detect a severe change in the metric.
56. The system of claim 53 , wherein the metric is a bias force.
57. The system of claim 52 , wherein the instructions to write a final servo pattern on the rotatable medium based on the width; include instructions to:
select a track density;
select a capacity; and
determine a first user track and a final user track based on the track density and the capacity;
wherein a distance between said ramp and the first user track is at least a minimum outer guard band and a distance between said crash stop and the final user track is at least a minimum inner guard band.
58. The system of claim 52 , wherein the instructions to write a final servo pattern on the rotatable medium based on the width; include instructions to:
select an outer guard band;
select an inner guard band;
select a capacity; and
determine a track density based on the capacity, the outer guard band, the inner guard band, and the width.
59. The system of claim 52 , wherein the instructions to write a final servo pattern on the rotatable medium based on the width; include instructions to:
select an outer guard band;
select an inner guard band;
select a track density; and
determine a capacity based on the track density, the outer guard band, the inner guard band, and the width.