Magnetic writer having multiple gaps with more uniform magnetic fields across the gaps

Patent metadata

Field	Value
Publication number	US-9257137-B2
Application number	US-201414151494-A
Country	US
Kind code	B2
Filing date	Jan 9, 2014
Priority date	Nov 3, 2009
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

A magnetic device according to one embodiment includes a source of flux; a magnetic pole having two or more gaps; and a low reluctance path positioned towards at least one of the gaps and riot positioned towards at least one other of the gaps for affecting a magnetic field formed at the at least one of the gaps when the source of flux is generating flux. Other disclosed embodiments include devices having coil turns with a non-uniform placement in the magnetic yoke for altering a magnetic field formed at the at least one of the gaps during writing. In further embodiments, a geometry of the magnetic pole near or at one of the gaps is different than a geometry of the magnetic pole near or at another of the gaps to help equalize fields formed at the gaps when the source of flux is generating flux.

First claim

What is claimed is:

1. A magnetic device, comprising:
a source of flux comprising a thin film coil having multiple turns;
a magnetic yoke coupled to the source of flux, the magnetic yoke having a pole with two or more gaps, wherein the coil turns have a non-uniform placement in the magnetic yoke for creating a higher magnetic field at one of the gaps than another of the gaps during writing,
wherein the gaps are positioned and configured to each write an individual transition to a magnetic medium upon energization of the coil.

2. A device as recited in claim 1 , wherein the device is constructed to operate with the magnetic medium running along the plane of deposition of the magnetic yoke.

3. A device as recited in claim 1 , wherein the gaps are configured to write servo patterns on a magnetic medium.

4. A device as recited in claim 1 , wherein a geometry of the magnetic yoke near or at one of the gaps is different than a geometry of the magnetic yoke near or at another of the gaps to help equalize fields formed at the gaps when the source of flux is generating flux.

5. A device as recited in claim 1 , wherein the coil turns are positioned more towards one of the gaps than another of the gaps.

6. A magnetic device, comprising:
a source of flux;
a magnetic pole coupled to the source of flux, the magnetic pole having two or more gaps, wherein the gaps are positioned and configured to each write an individual transition to a magnetic medium upon energization of the coil; and
wherein a geometry of the magnetic pole near or at one of the gaps is different than a geometry of the magnetic pole near or at another of the gaps to help equalize fields formed at the gaps when the source of flux is generating flux.

7. A device as recited in claim 6 , wherein the geometry of the magnetic pole includes a side portion of the pole being close to the one of the gaps for effectively adding a parallel flux path.

8. A device as recited in claim 6 , wherein the geometry of the magnetic pole includes at least two of the gaps having different throat heights.

9. A device as recited in claim 6 , wherein at least one of the gaps has a stepped geometry.

10. A device as recited in claim 6 , wherein the device is constructed to operate with the magnetic medium running along the plane of deposition of the magnetic pole.

11. A device as recited in claim 6 , wherein the device is constructed to operate with the magnetic medium running orthogonal to a plane of deposition of the pole.

12. A device as recited in claim 6 , wherein the gaps are configured to write servo patterns on a magnetic medium.

13. A device as recited in claim 6 , wherein the geometry equalizes magnetic fields formed at one of the gaps with a magnetic field formed at another of the gaps so that the magnetic fields are substantially equivalent.

14. A device as recited in claim 6 , wherein the source of flux comprises a thin film coil having multiple turns.

Assignees

• IBM

Inventors

• Biskeborn Robert G
• Herget Philipp
• Webb Bucknell C

Classifications

• G11B5/23 Primary

  Gap features {(G11B5/1871, G11B5/1875, G11B5/265, G11B5/29, G11B5/488 and subgroups, G11B5/4907 and subgroups, G11B5/4969 and subgroups take precedence)} · CPC title

• G11B5/2652

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

• G11B5/265 Primary

  Structure or manufacture of a head with more than one gap for erasing, recording or reproducing on the same track (G11B5/33 takes precedence {in thin film structures G11B5/31}) · CPC title

• G11B5/59638

  Servo formatting apparatuses, e.g. servo-writers · CPC title

• G11B5/3116 Primary

  Shaping of layers, poles or gaps for improving the form of the electrical signal transduced, e.g. for shielding, contour effect, equalizing, side flux fringing, cross talk reduction between heads or between heads and information tracks (G11B5/3113, G11B5/245 take precedence) · CPC title