Patterns for pre-formatted information on magnetic hard disk media
A magnetic disk media is physically preformatted to have a non-user data area providing any of a servo pattern, a gray code pattern and a timing line pattern. The non-user data area patterns are preformatted to have non-recordable regions with a radial width that is always less than the track pitch of the data area. In exemplary implementations, servo patterns, gray code patterns and timing line patterns are physically preformatted to have a recordable:non-recordable radial width ratio substantially equal to that of a user data area. In certain embodiments, non-magnetic or magnetically suppressed regions having cross-track dimension substantially equal to that of spaces between tracks in the user data area are consecutively offset in a cross-track direction from the discrete track recording pattern of the user data area.
1. A magnetic recording media, comprising:
a user data area with a track pitch and a non-recordable track space;
a non-user data area including non-recordable regions, wherein each non-recordable region has a radial width that is no greater than a radial width of the non-recordable track space.
2. The magnetic recording media of claim 1 , wherein the non-recordable regions comprise at least one of a servo pattern, a gray code pattern, and a timing line pattern.
3. A magnetic recording media, comprising:
a user data area with a track pitch and a non-recordable track space;
a non-user data area including non-recordable regions, wherein each non-recordable region has a radial width that is no greater than a radial width of the non-recordable track space, wherein the each non-recordable region in the non-user data area has a radial width substantially equal to the radial width of the track space; and wherein the non-user data area further comprises:
a first non-recordable region having a first radial offset from the user data area, the first radial offset being less than the track pitch.
4. The magnetic recording media of claim 3 , wherein the first non-recordable region has a radial offset from the user data area equal to the radial width of the track space.
5. The magnetic recording media of claim 4 , further comprising:
a second non-recordable region having a radial width equal to the first non-recordable region and having a second radial offset from the user data area that is less than the track pitch and greater than the first radial offset.
6. The magnetic recording media of claim 5 , wherein the first non-recordable region spans a different circumferential distance than the second non-recordable region, the first region has a radial offset of 25% of the track pitch, the second region has a radial offset of 50% of the track pitch and wherein each region has a radial width between 25% and 50% of the track pitch.
7. The magnetic recording media of claim 6 , further comprising a third and a fourth non-recordable region, the third non-recordable region having a radial offset of 75% of the track pitch and the fourth non-recordable region having no radial offset, wherein the third and fourth region each have a radial width between 25% and 50% of the track pitch.
8. The magnetic recording media of claim 3 , wherein the first non-recordable region spans a first circumferential distance in a gray code area, and is offset, in a radial direction, by 50% of the track pitch of the user data area and having a radial width of between 25% and 50% of the track pitch.
9. The magnetic recording media of claim 8 , wherein the first non-recordable region defines a transition representing a “1” within a bit cell for a first track of the user data area.
10. The magnetic recording media of claim 8 , wherein the first non-recordable region represents a boundary between bit cells.
11. A method of fabricating a magnetic recording media, comprising:
physically pre-formatting the magnetic recording media with a user data area with a track pitch and a non-recordable track space; and
physically pre-formatting the magnetic recording media with a non-user data area including non-recordable regions, wherein each non-recordable region has a radial width that is no greater than a radial width of the non-recordable track space and wherein a first non-recordable region has a first radial offset from the user data area that is less than the track pitch.
12. The method of fabricating a magnetic recording media of claim 11 , wherein the first non-recordable region is physically pre-formatted to have a radial width between 25% and 50% of the track pitch of the user data area.
13. The method of fabricating a magnetic recording media of claim 12 , wherein the first non-recordable region is physically-preformatted to have a radial width equal to a radial width of the non-recordable track space.
14. The method of fabricating a magnetic recording media of claim 11 , further comprising:
physically pre-formatting a second non-recordable region to have a radial width equal to the first non-recordable region and having a second radial offset from the user data area that is less than the track pitch and greater than the first radial offset.
15. The method of fabricating a magnetic recording media of claim 11 , wherein physically pre-formatting the first non-recordable region further comprises:
providing a masked magnetic media;
forming the first non-recordable region by selectively etching the masked magnetic media.
16. The method of fabricating a magnetic recording media of claim 11 , wherein physically pre-formatting the first non-recordable region further comprises:
embossing a masked substrate with a stamper, the stamper further including a negative replica of the user data area.
17. A stamper, comprising:
a substrate having a stamper pattern comprising:
a discrete track pattern with a track pitch and a track space; and
a control sector pattern including recessed regions, the recessed regions wherein each recessed region has a radial width that is no greater than a radial width of the track space and wherein a first recessed region is offset in the radial direction from the discrete track pattern by less than the track pitch.
18. The stamper of claim 17 , wherein the first recessed region has a radial width equal to a radial width of the track space.
19. A method of fabricating a stamper, comprising
providing a substrate having a surface;
forming a masking layer on the substrate; and
forming in the masking layer a stamper pattern comprising:
a discrete track pattern with a track pitch and a track space; and
a control sector pattern including recessed regions, each recessed region having a radial width that is no greater than a radial width of the track space and wherein a first recessed region is offset in the radial direction from the discrete track pattern by less than the track pitch.
20. The method of claim 19 , wherein the stamper pattern is formed using an electron beam.
21. The method of claim 20 , further comprising:
affixing the substrate to a stage operatively coupled to the electron beam;
defining a circumferential length of the track space by mechanically moving the stage while the electron beam is held in a first beam position incident to the substrate, the width of the electron beam defining a radial width of the track space;
offsetting the first recessed region by no greater than the track pitch by electromagnetically deflecting the electron beam from the first beam position to a second beam position while defining a circumferential length of the first recessed region by mechanically moving the stage.
22. A disk drive, comprising:
a magnetic recording disk, comprising:
a user data area having a track pitch and a non-recordable track space;
a non-user data area including non-recordable regions, wherein each non-recordable region has a radial width that is no greater than a radial width of the non-recordable track space; and
a head having a magneto-resistance read element operatively coupled to the magnetic recording disk.
23. A disk drive, comprising:
a magnetic recording disk, comprising:
a user data area having a track pitch and a non-recordable track space;
a non-user data area including non-recordable regions, wherein each non-recordable region has a radial width that is no greater than a radial width of the non-recordable track space, wherein a first non-recordable region has a first radial offset from the user data area that is equal to the track space; and
a head having a magneto-resistance read element operatively coupled to the magnetic recording disk.
24. A disk drive, comprising:
a magnetic recording disk, comprising:
a user data area having a track pitch and a non-recordable track space;
a non-user data area including non-recordable regions, wherein each non-recordable region has a radial width that is no greater than a radial width of the non-recordable track space, wherein each non-recordable region has a radial width substantially equal to the non-recordable track space in the user data area; and
a head having a magneto-resistance read element operatively coupled to the magnetic recording disk.
25. The disk drive of claim 24 , wherein the head has a leading edge and, when the leading edge is over a non-recordable region, the fraction of the leading edge over the non-recordable region is substantially independent of whether the non-recordable region is located in the user data area or the non-user data area.