High density timing based servo format

Patent metadata

Field	Value
Publication number	US-9443540-B2
Application number	US-201514849525-A
Country	US
Kind code	B2
Filing date	Sep 9, 2015
Priority date	Aug 12, 2013
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

A product according to one embodiment includes a magnetic recording tape having opposite ends and at least one servo track, a longitudinal axis of the magnetic recording tape being defined between the ends. The at least one servo track has a plurality of straight first magnetic bars, and a plurality of straight second magnetic bars spaced from the first magnetic bars. A width of each of the at least one servo track is defined in a direction perpendicular to the longitudinal axis of the magnetic recording tape between sides of the servo track, the sides of each servo track extending along opposite ends of the each of the first magnetic bars. Lengths of the second magnetic bars between outermost ends thereof are less than the width of the associated servo track.

First claim

What is claimed is:

1. A product, comprising:
a magnetic recording tape having opposite ends and at least one servo track, a longitudinal axis of the magnetic recording tape being defined between the ends;
the at least one servo track having a plurality of straight first magnetic bars and a plurality of straight second magnetic bars spaced from the first magnetic bars,
wherein a width of each of the at least one servo track is defined in a direction perpendicular to the longitudinal axis of the magnetic recording tape between sides of the servo track, the sides of each servo track extending along opposite ends of each of the first magnetic bars,
wherein lengths of the second magnetic bars between outermost ends thereof are less than the width of the associated servo track,
wherein the at least one servo track has a plurality of fourth magnetic bars, wherein the fourth magnetic bars are positioned closer to one side of the associated servo track than are the second magnetic bars.

2. The product as recited in claim 1 , wherein the at least one servo track has a plurality of third magnetic bars oriented to form chevron-like patterns with the first magnetic bars, the second magnetic bars being positioned between sets of the first and third magnetic bars in a servo frame.

3. The product as recited in claim 1 , wherein the first magnetic bars each have a longitudinal axis oriented between 2 and 88 degrees from the longitudinal axis of the magnetic recording tape.

4. The product as recited in claim 1 , wherein the lengths of the second magnetic bars are less than 80% of the width of the associated servo track, the second magnetic bars each having a longitudinal axis oriented substantially 90 degrees from the longitudinal axis of the magnetic recording tape.

5. The product as recited in claim 1 , wherein sets of the magnetic bars are grouped into servo frames, wherein a position of at least one of the first magnetic bars in one of the frames is different than in other frames thereby defining encoded information in the servo track.

6. A product, comprising:
a magnetic recording tape having opposite ends and at least one servo track, a longitudinal axis of the magnetic recording tape being defined between the ends;
the at least one servo track having a plurality of straight first magnetic bars and a plurality of straight second magnetic bars spaced from the first magnetic bars,
wherein a width of each of the at least one servo track is defined in a direction perpendicular to the longitudinal axis of the magnetic recording tape between sides of the servo track, the sides of each servo track extending along opposite ends of each of the first magnetic bars,
wherein lengths of the second magnetic bars between outermost ends thereof are less than the width of the associated servo track,
wherein the lengths of at least some of the second magnetic bars are one half a width of the associated servo track plus or minus 0.25 to 3 microns.

7. The product as recited in claim 1 , wherein the lengths of at least some of the second magnetic bars are one half a width of the associated servo track plus or minus 0.25 to 3 microns.

8. An apparatus, comprising:
a magnetic head;
a drive mechanism for passing the magnetic recording tape of claim 1 over the magnetic head; and
a controller electrically coupled to the magnetic head, the controller being configured to decode the servo track(s) of the magnetic recording tape.

9. An apparatus, comprising:
a magnetic head having at least one servo writer for writing the magnetic bars to the magnetic recording tape of claim 1 ;
a drive mechanism for passing the magnetic recording tape over the magnetic head; and
a controller electrically coupled to the magnetic head.

10. A computer program product for writing servo tracks on a magnetic recording tape, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory signal per se, the program instructions executable by a controller to cause the controller to perform a method comprising:
cause, by the controller, writing of at least one servo track on a magnetic recording tape,
the at least one servo track having a plurality of first magnetic bars and a plurality of second magnetic bars,
wherein a width of each of the at least one servo track is defined between sides of the servo track in a direction perpendicular to a longitudinal axis of the magnetic recording tape, the sides of each servo track extending along ends of the first magnetic bars,
wherein lengths of the second magnetic bars between outermost ends thereof are less than the width of the associated servo track,
straight portions of the second magnetic bars each having a longitudinal axis oriented substantially 90 degrees from the longitudinal axis of the magnetic recording tape.

11. The computer program product as recited in claim 10 , wherein the at least one servo track has a plurality of third magnetic bars oriented to form chevron-like patterns with the first magnetic bars, the second magnetic bars being positioned between sets of the first and third magnetic bars in a servo frame.

12. The computer program product as recited in claim 10 , wherein the first magnetic bars each have a longitudinal axis oriented between 2 and 88 degrees from the longitudinal axis of the magnetic recording tape.

13. The computer program product as recited in claim 10 , wherein the at least one servo track has a plurality of fourth magnetic bars, wherein the fourth magnetic bars are positioned closer to one side of the associated servo track than are the second magnetic bars.

14. The computer program product as recited in claim 10 , wherein the lengths of the second magnetic bars are less than 80% of the width of the associated servo track.

15. The computer program product as recited in claim 10 , wherein sets of the magnetic bars are grouped into servo frames, wherein a position of at least one of the first magnetic bars in one of the frames is different than in other frames thereby defining encoded information in the servo track.

16. An apparatus, comprising:
the computer program product as recited in claim 10 ;
a magnetic head;
a drive mechanism for passing a magnetic recording tape over the magnetic head; and
the controller electrically coupled to the magnetic head.

Assignees

• IBM

Inventors

• Biskeborn Robert G
• Lantz Mark A

Classifications

• G11B5/584 Primary

  for track following on tapes · CPC title

• G11B5/00817 Primary

  on longitudinal tracks only, e.g. for serpentine format recording · CPC title

• G11B20/1202

  with longitudinal tracks only · CPC title

• G11B15/18

  Driving; Starting; Stopping; Arrangements for control or regulation thereof {(G11B15/56 takes precedence)} · CPC title