Asperity and head-media contact detection using multi-stage temperature coefficient of resistance sensor

Patent metadata

Field	Value
Publication number	US-9373361-B2
Application number	US-201514827584-A
Country	US
Kind code	B2
Filing date	Aug 17, 2015
Priority date	Nov 17, 2010
Publication date	Jun 21, 2016
Grant date	Jun 21, 2016

Abstract

A multi-stage sensor is situated on the head transducer and configured to interact with a magnetic recording medium. A first sensor stage of the multi-stage sensor has a temperature coefficient of resistance. A second sensor stage of the multi-stage sensor is coupled to the first sensor and has a temperature coefficient of resistance. The first sensor stage is configured to preferentially sense asperities of the media relative to the second sensor stage, and the second sensor stage configured to preferentially sense proximity to, and contact with, a surface of the media relative to the first sensor stage. The first and second sensor stages may be connected in series or in parallel.

First claim

What is claimed is:

1. An apparatus, comprising:
a slider supporting a read/write transducer configured to interact with a magnetic recording medium, the slider comprising an airbearing surface; and
a multi-element sensor situated on the transducer at or near the airbearing surface, the multi-element sensor comprising at least three sensor elements each having a temperature coefficient of resistance;
wherein at least two of the at least three sensor elements are arranged in a co-parallel relationship on the transducer and configured to sense for asperities of the medium, contact between the slider and the medium, slider-medium spacing changes, or topographical surface features of the medium, and one of the at least three sensor elements is configured as a dual-stage sensor comprising a first sensor stage configured to sense asperities of the medium and a second sensor stage configured to sense for contact and spacing changes between the slider and the medium.

2. The apparatus of claim 1 , wherein:
each of the at least three sensor elements has a length, a width, and a depth; and
at least one of the length, the width, and the depth is about 10 μm.

3. The apparatus of claim 1 , wherein each of the at least three sensor elements is situated at a close point of the transducer.

4. The apparatus of claim 1 , wherein the at least three sensor elements are coupled in series.

5. The apparatus of claim 1 , wherein at least some of the at least three sensor elements are coupled in parallel.

6. The apparatus of claim 1 , wherein the at least three sensor elements are configured to sense for asperities of the medium.

7. The apparatus of claim 1 , wherein the at least three sensor elements are configured to sense for contact between the slider and the medium.

8. The apparatus of claim 1 , wherein the at least three sensor elements are configured to sense for topographical surface features of the medium.

9. The apparatus of claim 1 , further comprising a detector coupled to the multi-element sensor and configured to detect the asperities of the medium, contact between the slider and the medium, and the slider-medium spacing changes.

10. An apparatus, comprising:
a slider supporting a read/write transducer configured to interact with a magnetic recording medium, the slider comprising an airbearing surface; and
a multi-element sensor situated on the transducer at or near the airbearing surface, the multi-element sensor comprising at least three sensor elements each having a temperature coefficient of resistance;
wherein at least two of the at least three sensor elements are arranged in a co-parallel relationship on the transducer, and one of the at least three sensor elements is configured as a dual-stage sensor comprising a first sensor stage configured to sense asperities of the medium and a second sensor stage configured to sense for contact and spacing changes between the slider and the medium.

11. The apparatus of claim 10 , wherein:
each of the at least three sensor elements has a length, a width, and a depth; and
at least one of the length, the width, and the depth is about 10 μm.

12. The apparatus of claim 10 , wherein each of the at least three sensor elements is situated at a close point of the transducer.

13. The apparatus of claim 10 , further comprising a detector coupled to the multi-element sensor and configured to detect the asperities of the medium, contact between the slider and the medium, and the spacing changes.

14. An apparatus, comprising:
a slider supporting a read/write transducer configured to interact with a magnetic recording medium, the slider comprising an airbearing surface; and
a multi-element sensor situated on the transducer at or near the airbearing surface, the multi-element sensor comprising at least three sensor elements each having a temperature coefficient of resistance;
wherein the at least three sensor elements are configured to sense for asperities of the medium, contact between the slider and the medium, slider-medium spacing changes, or topographical surface features of the medium, and one of the at least three sensor elements is configured as a dual-stage sensor comprising a first sensor stage configured to sense asperities of the medium and a second sensor stage configured to sense for contact and spacing changes between the slider and the medium.

15. The apparatus of claim 14 , wherein:
each of the at least three sensor elements has a length, a width, and a depth; and
at least one of the length, the width, and the depth is about 10 μm.

16. The apparatus of claim 14 , wherein each of the at least three sensor elements is situated at a close point of the transducer.

17. The apparatus of claim 14 , further comprising a detector coupled to the multi-element sensor and configured to detect the asperities of the medium, contact between the slider and the medium, the slider-medium spacing changes, and the topographical surface features of the medium.

Assignees

• Seagate Technology Llc

Inventors

• Kunkel Gary Joseph
• Brand John L

Classifications

• G11B5/3133

  including layers not usually being a part of the electromagnetic transducer structure and providing additional features, e.g. for improving heat radiation, reduction of power dissipation, adaptations for measurement or indication of gap depth or other properties of the structure (G11B5/3106 takes precedence) · CPC title

• G11B5/607 Primary

  using thermal means · CPC title

• G11B7/0948

  specially adapted for detection and avoidance or compensation of imperfections on the carrier, e.g. dust, scratches, dropouts (G11B7/095 takes precedence) · CPC title

• G11B27/36 Primary

  Monitoring, i.e. supervising the progress of recording or reproducing {(for digital recording G11B20/00 and s.gr.; for monitoring, testing or measuring of TV recorders of the type covered by H04N5/76 and subgroups, see H04N17/06)} · CPC title

• G11B7/121

  Protecting the head, e.g. against dust or impact with the record carrier · CPC title