High density timing based servo format

• US 8,902,537 B1
• Filed: 08/12/2013
• Issued: 12/02/2014
• Est. Priority Date: 08/12/2013
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Biskeborn, Robert G., Lantz, Mark A.
• Primary Examiner(s): HINDI, NABIL Z
• Application Number:
  US13/964,614
• Time in Patent Office: 477 Days
• Field of Search: 360/77.12, 360/75, 360/78.02, 360/48, 360/49, 360/71, 360/53, 360/77.08, 360/78.14, 360/78.15, 360/77.05
• US Class Current: 360/77.12
• CPC Class Codes: G11B 15/18 Driving; Starting; Stopping; Arrangements for control or regulation thereof G11B15/56 takes precedence
• CPC Class Codes: G11B 20/1202 with longitudinal tracks only
• CPC Class Codes: G11B 5/00817 on longitudinal tracks only, e.g. for serpentine format recording
• CPC Class Codes: G11B 5/584 for track following on tapes

Abstract

A product having a magnetic recording tape with at least one servo track, the at least one servo track having a plurality of first magnetic bars and a plurality of second magnetic bars. The first magnetic bars each have a longitudinal axis oriented between 2 and 88 degrees from the longitudinal axis of the magnetic recording tape. 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 ends of the first magnetic bars. Lengths of the second magnetic bars along the longitudinal axes thereof are less than the width of the associated servo track.

Claims

1. A product, comprising:

a magnetic recording tape having opposite ends, a longitudinal axis of the magnetic recording tape being defined between the ends;

the magnetic recording tape having at least one servo track,

the at least one servo track having a plurality of first magnetic bars and a plurality of second magnetic bars,

the first magnetic bars each having a longitudinal axis oriented between 2 and 88 degrees from the longitudinal axis of the magnetic recording tape,

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 ends of the first magnetic bars,

wherein lengths of the second magnetic bars along, the longitudinal axes thereof are less than 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.

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 2, wherein the second magnetic bars are positioned away from points of closest approach of the first and third magnetic bars closest thereto.

4. The product as recited in claim 3, 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.

5. The product as recited in claim 1, 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.

6. 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.

7. 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.

8. The product as recited in claim 1, wherein the lengths of at least sonic of the second magnetic bars are one half a width of the servo band plus 0.25 to 3 microns.

9. 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 servo band minus 0.25 to 3 microns.

10. 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.

11. 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.

12. A method, comprising:

writing 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,

the first magnetic bars each having a longitudinal axis oriented between 2 and 88 degrees from the longitudinal axis of the magnetic recording tape,

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 the longitudinal axis of the magnetic recording tape,

the sides of each servo track extending along ends of the first magnetic bars,

wherein lengths of at least some of the second magnetic bars along the longitudinal axes thereof are greater than one half the width of the associated servo track and less than the width of the associated servo track.

13. The method as recited in claim 12, 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.

14. The method as recited in claim 13, wherein the second magnetic bars are positioned away from points of closest approach of the first and third magnetic bars closest thereto.

15. The method as recited in claim 14, 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.

16. The method as recited in claim 12, 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.

17. The method as recited in claim 12, 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.

18. The method as recited in claim 12, 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.

19. An apparatus, comprising:

a magnetic head having at least one servo writer p perform the method of claim 12;

a drive mechanism for passing the magnetic recording tape over the magnetic head; and

a controller electrically coupled to the magnetic head.

20. An apparatus, comprising:

a magnetic head;

a drive mechanism for passing a magnetic recording tape over the magnetic head; and

a controller electrically coupled to the magnetic head, the controller being configured to perform the method of claim 12.