Systems and methods for reducing crosstalk between adjacent writers

• US 8,310,777 B2
• Filed: 09/09/2009
• Issued: 11/13/2012
• Est. Priority Date: 09/09/2009
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Biskeborn, Robert G., Herget, Philipp, Jubert, Pierre-Olivier
• Primary Examiner(s): Mercedes, Dismery
• Application Number:
  US12/556,452
• Publication Number:
  US 20110058271A1
• Time in Patent Office: 1,161 Days
• Field of Search: None
• US Class Current: 360/61
• CPC Class Codes: G11B 20/10009 Improvement or modification of read or write signals
• CPC Class Codes: G11B 5/00813 magnetic tapes
• CPC Class Codes: G11B 5/00826 comprising a plurality of single poles or gaps or groups thereof operative at the same time

Abstract

In one general embodiment, a recording system controller includes a controller controlling a timing of flux switching of adjacent pairs of writers such that the writers in a given pair do not switch substantially concurrently, and reducing a current of one of the writers in the pair while the adjacent writer is writing a transition. In another general embodiment, a recording system controller includes a controller controlling a timing of pulse writing of adjacent pairs of writers such that the writers in a given pair do not pulse substantially concurrently. In yet another general embodiment, a method includes controlling a timing of pulse writing or flux switching of adjacent pairs of writers such that the writers in a given pair do not pulse or switch substantially concurrently.

Claims

1. A recording system controller, comprising:

a controller configured to control a timing of flux switching of adjacent pairs of writers such that the writers in a given pair do not switch substantially concurrently when the writers in the pair are concurrently writing parallel data tracks, and to reduce a current of one of the writers in the pair while the adjacent writer is writing a transition in the data track being written thereby,

wherein the current is reduced at regular intervals.

2. A recording system controller as recited in claim 1, wherein the controller controls the timing of the switching to create transitions on simultaneously-written data tracks on a magnetic medium that are out of phase with each other.

3. A recording system controller as recited in claim 1, wherein the current is reduced to about zero while the adjacent writer is writing a transition.

4. A recording system controller as recited in claim 1, wherein the controller is further configured to receive a servo signal from a servo reader reading a servo track, the controller being configured to align the writers with the data tracks based on the servo signal from the servo reader.

5. A recording system controller as recited in claim 1, wherein the current of the one of the writers is reduced to a point that the one of the writers is no longer writing while the adjacent writer is writing a transition.

6. A recording system comprising the controller as recited in claim 1 and the writers, wherein the writers are formed on a common substrate.

7. A recording system controller as recited in claim 6, wherein writers in an odd position switch concurrently, wherein writers in an even position switch concurrently, wherein the current is reduced but not completely turned off thereby continuing to write with the reduced current.

8. A recording system controller as recited in claim 1, wherein writers in an odd position switch concurrently, wherein writers in an even position switch concurrently.

9. A recording system controller as recited in claim 1, wherein writers in first predefined positions switch concurrently, wherein writers in second predefined positions switch concurrently.

10. A recording system controller as recited in claim 9, wherein writers in third predefined positions switch concurrently.

11. A magnetic recording system, comprising:

a magnetic head comprising a plurality of writers;

a drive mechanism for passing a magnetic recording medium over the head;

a controller as recited in claim 1.

12. A recording system controller, comprising:

a controller configured to control a timing of flux switching of adjacent pairs of writers such that the writers in a given pair do not switch substantially concurrently when the writers are concurrently writing data tracks, and to reduce a current of one of the writers in the pair while the adjacent writer is writing a transition,

wherein a time period that the current is reduced is characterized in that a continuous pattern is written on a medium even when the current is reduced.

13. A recording system controller as recited in claim 12, wherein the current is reduced but not completely turned off, wherein the adjacent writers are arranged to write parallel data tracks.

14. A recording system comprising the controller as recited in claim 12, and further comprising the writers arranged to write parallel data tracks, wherein the writers are formed on a common substrate, wherein the writers in the given pair are never powered simultaneously.

15. A recording system, comprising:

a controller configured to control a timing of flux switching of adjacent pairs of writers such that the writers in a given pair do not switch substantially concurrently when the writers are concurrently writing parallel data tracks, and to reduce a current of one of the writers in the pair at regular intervals corresponding to times when the adjacent writer is writing a transition.

16. A method, comprising:

controlling a timing of pulse writing or flux switching of pairs of adjacent writers such that the writers in a given pair do not pulse or switch substantially concurrently, wherein the current of one of the writers in the given pair is reduced to a point that the one of the writers is no longer writing while the adjacent writer is writing a transition,

wherein a time period that the current is reduced is characterized in that a continuous pattern is written on a medium even when the current is reduced.

17. A method as recited in claim 16, wherein the current of the one of the writers in the given pair is reduced to about zero while the adjacent writer is writing a transition, wherein the pair of adjacent writers are arranged to write parallel data tracks.

18. A method as recited in claim 16, wherein the current is reduced on regular intervals.

19. A method as recited in claim 16, wherein the writers are formed on a common substrate, wherein the current is reduced but not completely turned off.

20. A method as recited in claim 16, further comprising receiving a servo signal from a servo reader reading a servo track, the controller being configured to align the writers with the data tracks based on the servo signal from the servo reader.