Magnetic head and system having offset arrays

Patent metadata

Field	Value
Publication number	US-9754616-B2
Application number	US-201514860464-A
Country	US
Kind code	B2
Filing date	Sep 21, 2015
Priority date	May 1, 2013
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

A computer program product for orienting a head includes a computer readable storage medium having program instructions embodied therewith. The program instructions are readable and/or executable by a controller to cause the controller to: determine a desired pitch for transducers for reading and/or writing to a magnetic tape; and cause a mechanism to orient a head to achieve the desired pitch. The array of a first of the modules is offset from the array of a second of the modules in a first direction parallel to the axis of the array of the second module such that the transducers of the first module are about aligned with the transducers of the second module in the intended direction of tape travel thereacross when the axes are oriented at an angle greater than 0.2° relative to a line oriented perpendicular to the intended direction of tape travel.

First claim

What is claimed is:

1. A computer program product for orienting a head, the computer program product comprising a non-transitory computer readable storage medium having program instructions embodied therewith, the program instructions readable and/or executable by a controller to cause the controller to:
determine, by the controller, a desired pitch for transducers for reading and/or writing to a magnetic tape; and
cause, by the controller, a mechanism to orient a head to achieve the desired pitch, the head having at least two opposing modules generally aligned with each other in an intended direction of tape travel thereacross, positions of the two modules being fixed relative to each other, each module having an array of the transducers, wherein an axis of each array is defined between opposite ends thereof, wherein the array of a first of the modules is offset from the array of a second of the modules in a first direction parallel to the axis of the array of the second module such that the transducers of the first module are about aligned with the transducers of the second module in the intended direction of tape travel thereacross when the axes are oriented at an angle between greater than 0.2° and about 10° relative to a line oriented perpendicular to the intended direction of tape travel,
wherein determining the desired pitch for the transducers for reading and/or writing to the tape includes determining a state of expansion of the tape based on a readback signal from the tape, the readback signal being derived from the transducers of the modules of the parallel arrays when the axes of the arrays are oriented at an angle greater than 0.2° relative to the line oriented perpendicular to the intended direction of tape travel thereacross.

2. The computer program product as recited in claim 1 , comprising program instructions readable and/or executable by the controller to cause the controller to determine a state of the tape, the desired pitch being determined based on the state of the tape.

3. A computer program product as recited in claim 1 , wherein the head has only two modules.

4. A computer program product as recited in claim 1 , wherein the head has three modules, a third one of the modules being positioned between the first and second modules, wherein the array of the third module is offset from the array of the first module in the first direction, wherein an extent of the offset of the array of the third module relative to the array of the first module is less than an extent of the offset of the array of the second module relative to the array of the first module.

5. The computer program product as recited in claim 4 , wherein the first and second modules are configured for data reading and are not configured for data writing, wherein the third module is configured for data writing and is not configured for data reading.

6. The computer program product as recited in claim 4 , wherein the first and second modules are configured for data writing and are not configured for data reading, wherein the third module is configured for data reading and is not configured for data writing.

7. The computer program product as recited in claim 1 , wherein the angle is between 0.25° and about 5°.

8. The computer program product as recited in claim 1 , comprising program instructions readable and/or executable by the controller to cause the controller to control the mechanism for altering the angle at which the axes are oriented relative to the line oriented perpendicular to the intended direction of tape travel to achieve the desired pitch based on the state of expansion of the tape.

9. The computer program product as recited in claim 1 , comprising program instructions readable and/or executable by the controller to cause the controller to control the mechanism for altering the angle at which the axes are oriented relative to the line oriented perpendicular to the intended direction of tape travel to achieve the desired pitch based on a skew of the tape.

10. A computer program product for orienting a head, the computer program product comprising a non-transitory computer readable storage medium having program instructions embodied therewith, the program instructions readable and/or executable by a controller to cause the controller to:
determine, by the controller, a state of expansion of a magnetic tape based on a readback signal of the tape;
determine, by the controller, a desired pitch for transducers for reading and/or writing to the tape based on the expansion of the tape; and
control, by the controller, a mechanism for orienting a head having the transducers based on the state of expansion of the tape, the head having at least two opposing modules generally aligned with each other in an intended direction of tape travel thereacross, positions of the two modules being fixed relative to each other, each module having an array of the transducers, wherein an axis of each array is defined between opposite ends thereof, wherein the array of a first of the modules is offset from the array of a second of the modules in a first direction parallel to the axis of the array of the second module such that the transducers of the first module are about aligned with the transducers of the second module in the intended direction of tape travel thereacross when the axes are oriented at an angle between greater than 0.25° and about 5° relative to a line oriented perpendicular to the intended direction of tape travel,
wherein determining the state of expansion of the tape includes orienting the head to orient the axes at an angle greater than 0.2° relative to the line oriented perpendicular to the intended direction of tape travel during acquisition of the readback signal of the tape, the readback signal being derived from the transducers of the modules of the parallel arrays.

11. The computer program product as recited in claim 10 , wherein determining the desired pitch for transducers for reading and/or writing to the tape is also based on a skew of the tape.

12. A computer program product as recited in claim 10 , wherein the head has three modules, a third one of the modules being positioned between the first and second modules, wherein the array of the third module is offset from the array of the first module in the first direction, wherein an extent of the offset of the array of the third module relative to the array of the first module is less than an extent of the offset of the array of the second module relative to the array of the first module.

13. The computer program product as recited in claim 12 , wherein the first and second modules are configured for data reading and are not configured for data writing, wherein the third module is configured for data writing and is not configured for data reading.

14. The computer program product as recited in claim 12 , wherein the first and second modules are configured for data writing and are not configured for data reading, wherein the third module is configured for data reading and is not configured for data writing.

15. The computer program product as recited in claim 11 , wherein the head has only two modules.

Assignees

• IBM

Inventors

• Biskeborn Robert G
• Herget Philipp
• Lo Calvin S

Classifications

• G11B5/4893

  relative to moving tape · CPC title

• G11B5/584 Primary

  for track following on tapes · CPC title

• G11B5/00826

  comprising a plurality of single poles or gaps or groups thereof operative at the same time · CPC title

• G11B5/09

  Digital recording · CPC title

• G11B5/2652

  with more than one gap simultaneously operative (with controlled single gap G11B5/245) · CPC title