Write delay to de-skew data in read while write function for tape storage devices

Patent metadata

Field	Value
Publication number	US-9318138-B2
Application number	US-201414574278-A
Country	US
Kind code	B2
Filing date	Dec 17, 2014
Priority date	Jul 17, 2014
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

A controller, according to one embodiment, has at least some hardware components, and is configured to determine an offset between adjacent arrays of transducers in a direction perpendicular to an intended direction of media travel when a magnetic head having the arrays is positioned at a first position, cause the magnetic head to tilt to a second position, and delay write operations performed by at least some of the transducers in a first of the arrays such that data written by the transducers in the first array is readable by a second array of read transducers aligned in the direction orthogonal to the intended direction of media travel without implementing readback delays corresponding to the write delays.

First claim

What is claimed is:

1. A controller having at least some hardware components, the controller configured to:
determine, by the controller, an offset between adjacent arrays of transducers in a direction perpendicular to an intended direction of media travel when a magnetic head having the arrays is positioned at a first position;
cause, by the controller, the magnetic head to tilt to a second position; and
delay, by the controller, write operations performed by at least some of the transducers in a first of the arrays such that data written by the transducers in the first array is readable by a second array of read transducers aligned in the direction orthogonal to the intended direction of media travel without implementing readback delays corresponding to the write delays,
wherein the delay is based at least in part on the offset.

2. The controller as recited in claim 1 , wherein the delayed write operations are performed while the magnetic head is in the second position.

3. The controller as recited in claim 1 , wherein the controller is further configured to:
tilt the magnetic head to a position in the direction perpendicular to the intended direction of media travel; and
read magnetic transitions on a magnetic medium.

4. The controller as recited in claim 1 , wherein the first position is perpendicular to the intended direction of media travel.

5. The controller as recited in claim 1 , wherein the controller is further configured to:
selectively adjust the position of the magnetic head to compensate for at least one of tape lateral expansion/contraction and tape skew.

6. An apparatus having the controller as recited in claim 1 , and further comprising:
the magnetic head; and
a drive mechanism for passing a magnetic medium over the head.

7. The apparatus as recited in claim 6 , wherein one of the arrays includes read transducers, the array having a longitudinal axis aligned about parallel to the longitudinal axis of the first array.

8. The apparatus as recited in claim 6 , wherein the magnetic head includes three modules.

9. A controller-implemented method, comprising:
determining, by a controller, an offset between adjacent arrays of transducers in a direction perpendicular to an intended direction of media travel when a magnetic head having the arrays is positioned at a first position;
causing, by the controller, tilting the magnetic head to a second position; and
delaying, by the controller, write operations performed by at least some of the transducers in a first of the arrays such that data written by the transducers in the first array is readable by a second array of read transducers aligned in the direction orthogonal to the intended direction of media travel without implementing readback delays corresponding to the write delays, wherein the delay is based at least in part on the offset.

10. The method as recited in claim 9 , wherein the write operations are performed while the magnetic head is in the second position.

11. The method as recited in claim 9 , comprising:
tilting the magnetic head to a position in the direction perpendicular to the intended direction of media travel; and
reading magnetic transitions on a magnetic medium.

12. The method as recited in claim 9 , wherein the first position is perpendicular to the intended direction of media travel.

13. The method as recited in claim 9 , comprising selectively adjusting the position of the magnetic head to compensate for at least one of tape lateral expansion/contraction and tape skew.

14. A controller having at least some hardware components, the controller configured to:
determine, by the controller, an offset between first and second arrays of transducers on a magnetic head in a direction perpendicular to an intended direction of media travel when the magnetic head is positioned at a first position;
cause, by the controller, the magnetic head to tilt a second position;
wherein at least one of the arrays of transducers includes write transducers;
wherein the arrays of transducers have longitudinal axes aligned at the second position greater or less than 0 degrees from the longitudinal axes of the arrays of transducers aligned at the first position;
cause, by the controller, writing by the write transducers while the magnetic head is in the second position; and
cause, by the controller, a delay in writing by at least some of the write transducers to provide magnetic transitions on a magnetic medium as if the longitudinal axis of the array was aligned in the direction perpendicular to the intended direction of media travel,
wherein the writing delays are based at least in part on the offset.

15. The controller as recited in claim 14 , wherein the magnetic transitions are readable by an array of read transducers aligned in the direction orthogonal to the intended direction of media travel without implementing readback delays corresponding to the writing delays.

16. The controller as recited in claim 14 , wherein one of the arrays includes read transducers, the array having a longitudinal axis aligned about parallel to the longitudinal axis of the array of write transducers.

17. The controller as recited in claim 14 , wherein the controller is further configured to:
tilt the magnetic head to a position in the direction perpendicular to the intended direction of media travel; and
read magnetic transitions on a magnetic medium.

18. The controller as recited in claim 14 , wherein the first position is perpendicular to the intended direction of media travel.

19. An apparatus having the controller as recited in claim 14 , and further comprising:
the magnetic head; and
a drive mechanism for passing a magnetic medium over the head.

Assignees

• IBM

Inventors

• Bui Nhan X
• Taketomi Tomoko
• Tanaka Keisuke
• Tsuruta Kazuhiro

Classifications

• G11B27/10

  Indexing; Addressing; Timing or synchronising; Measuring tape travel · CPC title

• G11B5/02

  Recording, reproducing, or erasing methods; Read, write or erase circuits therefor · CPC title

• G11B5/584 Primary

  for track following on tapes · CPC title

• G11B5/56

  with provision for moving the head {support} for the purpose of adjusting the position of the head relative to the record carrier, e.g. manual adjustment for azimuth correction or track centering ({G11B5/52,} G11B5/54, G11B5/58 take precedence) · CPC title

• G11B5/00813

  magnetic tapes · CPC title