Template pattern for improving printed media self-servo writing
View Patent ↗Template patterns 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 template pattern, zig-bursts within a servo wedge describing radial positioning are replaced with 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. 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 template pattern for a reference surface of a disk for a hard disk drive having a head connected with a rotary actuator, the template pattern comprising:
a servo wedge having a first end and a second end disposed between the first end and an outer diameter of the disk, the servo wedge including:
a plurality of pulses extending from the first end to the second end;
a plurality of zig-bursts extending from the first end to the second end, the zig-bursts forming a zig angle relative to the plurality of pulses, the zig angle varying along at least a portion of the plurality of zig-bursts; and
a plurality of zag-bursts extending from the first end to the second end, the zag-bursts forming a zag angle relative to the plurality of pulses, the zag angle being a chevron angle; and
wherein the zig angle at the second end is a chevron angle and the zig angle at the first end is less than the chevron angle;
wherein the zig angle and the zag angle diverge from the plurality of pulses in opposite directions relative to the plurality of pulses.
2. The template pattern of claim 1 , wherein the plurality of pulses trace an arc from the first end to the second end such that the arc follows a motion of the head.
3. The template pattern of claim 1 , wherein the plurality of pulses can be continuous or discontinuous.
4. The template pattern of claim 1 , wherein the zig angle varies continuously between the first end and the second end.
5. The template pattern of claim 1 , wherein the zig angle abruptly changes from a variable angle to the chevron angle.
6. The template pattern of claim 1 , wherein the zig angle is equivalent to approximately a sum of the chevron angle and a skew of the head at the first end.
7. The template pattern of claim 6 , wherein the zig angle is constant relative to a radial line extending from the first end to the second end.
8. A template pattern for a reference surface of a disk for a hard disk drive having a head connected with a rotary actuator, the template pattern comprising:
a servo wedge having a first end and a second end disposed between the first end and an outer diameter of the disk, the servo wedge including:
a plurality of pulses extending from the first end to the second end;
a plurality of zig-bursts extending from the first end to the second end, the zig-bursts forming a zig angle relative to the plurality of pulses, the zig angle varying along at least a portion of the plurality of zig-bursts; and
a plurality of zag-bursts extending from the first end to the second end, the zag-bursts forming a zag angle relative to the plurality of pulses, the zag angle being a chevron angle; and
wherein the zig angle at the first end is zero and the zig angle at the second end is a chevron angle;
wherein the zig angle and the zag angle diverge from the plurality of pulses in opposite directions relative to the plurality of pulses.
9. The template pattern of claim 8 , wherein the plurality of pulses trace an arc from the first end to the second end such that the arc follows a motion of the head.
10. The template pattern of claim 9 , wherein the plurality of pulses can be continuous or discontinuous along the arc.
11. The template pattern of claim 8 , wherein the zig angle varies continuously between the first end and the second end.
12. The template pattern of claim 8 , wherein the zig angle abruptly changes from zero to the chevron angle.
13. A template pattern for a rotatable data storage medium, the template pattern comprising:
a servo wedge having a first end and a second end, each servo wedge including:
a plurality of pulses extending along a stroke from the first end to the second end, each pulse being continuous or discontinuous;
a plurality of zig-bursts disposed along the stroke, the zig-bursts forming a zig angle relative to the plurality of pulses, the zig angle varying along at least a portion of the plurality of zig-bursts; and
a plurality of zag-bursts disposed along the stroke, the zag-bursts forming a zag angle relative to the plurality of pulses, wherein the zag angle is a chevron angle;
wherein the zig angle at the first end is zero and the zig angle at the second end is a chevron angle;
wherein the zig angle and the zag angle diverge from the plurality of pulses in opposite directions relative to the plurality of pulses.
14. The template pattern of claim 13 , wherein the plurality of pulses trace an arc from the first end to the second end.
15. The template pattern of claim 13 , wherein the zig angle varies continuously between the first end and the second end.
16. The template pattern of claim 13 , wherein the zig angle abruptly changes from zero to the chevron angle.
17. A template pattern for a reference surface of a disk for a hard disk drive having a head connected with a rotary actuator, the template pattern comprising:
a servo wedge having a first end and a second end disposed between the first end and an outer diameter of the disk, the servo wedge including:
a plurality of pulses extending from the first end to the second end;
a plurality of zig-bursts extending from the first end to the second end, the zig-bursts forming a zig angle relative to the plurality of pulses, wherein the zig angle is a chevron angle; and
a plurality of zag-bursts extending from the first end to the second end, the zag-bursts forming a zag angle relative to the plurality of pulses, the zag angle varying along at least a portion of the plurality of zag-bursts;
wherein the zag angle at the first end is zero and the zag angle at the second end is a chevron angle;
wherein the zig angle and the zag angle diverge from the plurality of pulses in opposite directions relative to the plurality of pulses.
18. The template pattern of claim 17 , wherein the plurality of pulses trace an arc from the first end to the second end such that the arc follows a motion of the head.
19. The template pattern of claim 18 , wherein the plurality of pulses can be continuous or discontinuous along the arc.
20. The template pattern of claim 17 , wherein the zag angle varies continuously between the first end and the second end.
21. The template pattern of claim 17 , wherein the zag angle abruptly changes from zero to the chevron angle.
22. A template pattern , comprising:
a servo wedge having a first end and a second end, each servo wedge including:
a plurality of pulses extending from the first end to the second end, each pulse being continuous or discontinuous;
a plurality of zig-bursts extending from the first end to the second end, the zig-bursts forming a zig angle relative to the plurality of pulses, wherein the zig angle is a chevron angle; and
a plurality of zag-bursts extending from the first end to the second end, the zag-bursts forming a zag angle relative to the plurality of pulses;
wherein the zag angle at the first end is zero and the zag angle at the second end is a chevron angle;
wherein the zig angle and the zag angle diverge from the plurality of pulses in opposite directions relative to the plurality of pulses.
23. The template pattern of claim 22 , wherein the plurality of pulses trace an arc from the first end to the second end.
24. The template pattern of claim 22 , wherein the zag angle varies continuously between the first end and the second end.
25. The template pattern of claim 22 , wherein the zag angle abruptly changes from zero to the chevron angle.
26. A template pattern of a disk for a hard disk drive, the hard disk drive having a head connected with a rotary actuator, the template pattern comprising:
a servo wedge having a first end and a second end disposed between the first end and an outer diameter of the disk, the servo wedge including:
a pulse extending from the first end to the second end;
a plurality of zag-bursts extending from the first end to the second end, the zag-bursts forming a zag angle relative to the pulse, the zag angle varying along at least a portion of the zag-bursts; and
a plurality of zig-bursts extending from the first end to the second end, the zig-burst forming a zig angle relative to the pulse, the zig angle being a chevron angle; and
wherein the zag angle at the second end is the chevron angle and the zag angle at the first end is less than the chevron;
wherein the zig angle and the zag angle diverge from the pulse in opposite directions relative to the pulse.
27. The template pattern of claim 26 , wherein the pulse traces a path roughly corresponding to a path of the head when the head is moved from the first end to the second end.
28. The template pattern of claim 26 , wherein the zag angle varies continuously between the first end and the second end.
29. The template pattern of claim 26 , wherein the zag angle abruptly changes from zero to the chevron angle.
30. The template pattern of claim 26 , wherein the zag angle is equivalent to approximately a sum of the chevron angle and a skew of the head at the first end.