Magnetic recording and reproducing device having magnetic head with first and second reproducing element portions and magnetic reproducing method

Patent metadata

Field	Value
Publication number	US-9824703-B2
Application number	US-201615258509-A
Country	US
Kind code	B2
Filing date	Sep 7, 2016
Priority date	Feb 18, 2016
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

According to one embodiment, a magnetic recording and reproducing device includes a magnetic recording medium, a magnetic head, and a processor. The magnetic head includes a first reproducing element portion and a second reproducing element portion. The processor is configured to acquire a first signal and a second signal, and to output an output signal according to either one of the first signal and the second signal. The first signal is obtained by reproducing information recorded on a first recording region by the first reproducing element portion. The second signal is obtained by reproducing the information recorded on the first recording region by the second reproducing element portion.

First claim

What is claimed is:

1. A magnetic recording and reproducing device, comprising:
a magnetic recording medium;
a magnetic head including a first reproducing element portion and a second reproducing element portion; and
a processor configured to acquire a first signal and a second signal, and to output an output signal according to either one of the first signal and the second signal, the first signal being obtained by reproducing information recorded on a first recording region by the first reproducing element portion, the second signal being obtained by reproducing the information recorded on the first recording region by the second reproducing element portion,
wherein
the first reproducing element portion includes:
a first electrode,
a second electrode apart from the first electrode in a first direction,
a first signal detecting portion provided between the first electrode and the second electrode, and
a first side shield, at least a part of the first side shield overlapping the first signal detecting portion in a second direction crossing the first direction,

the second reproducing element portion includes:
a third electrode,
a fourth electrode apart from the third electrode in the first direction,
a second signal detecting portion provided between the third electrode and the fourth electrode, and
a second side shield, at least a part of the second side shield overlapping the second signal detecting portion in the second direction, a direction connecting the first electrode and the third electrode being along the first direction,

the second electrode includes a first non-magnetic metal layer, and
the fourth electrode includes a second non-magnetic metal layer.

2. The device according to claim 1 , wherein
the processor processes the first signal, and derives a first soft-decision information, and processes the second signal, and derives a second soft-decision information,
the processor derives a first difference between the first soft-decision information and a decision level, and a second difference between the second soft-decision information and the decision level, and
when an absolute value of the first difference is not less than an absolute value of the second difference, the either one of the first signal and the second signal is the first signal Sig 1 ,
when the absolute value of the first difference is smaller than the absolute value of the second difference, the either one of the first signal and the second signal is the second signal.

3. The device according to claim 1 , wherein
the processor acquires a third signal and a fourth signal,
the third signal is obtained by reproducing information recorded on a second recording region of the magnetic recording medium by the first reproducing element portion,
the fourth signal is obtained by reproducing the information recorded on the second recording region by the second reproducing element portion,
the processor further outputs another output signal according to either one of the third signal and the fourth signal.

4. The device according to claim 1 , wherein the first electrode includes a magnetic body.

5. The device according to claim 1 , wherein a direction connecting the first reproducing element portion and the second reproducing element portion is along the first direction.

6. The device according to claim 1 , wherein the magnetic head further includes an insulating layer provided between the first reproducing element portion and the second reproducing element portion.

7. The device according to claim 1 , wherein
a number of the first non-magnetic metal layer included in the second electrode is either one of odd number and even number, and
a number of the second non-magnetic metal layer included in the fourth electrode is other one of odd number and even number.

8. The device according to claim 7 , wherein a difference between the number of the first non-magnetic metal layer and the number of the second non-magnetic metal layer is 1.

9. The device according to claim 1 , wherein the second electrode further includes a plurality of magnetic layers, and
the first non-magnetic metal layer is provided between the plurality of magnetic layers.

10. The device according to claim 1 , wherein the second electrode includes a first antiferromagnetic layer.

11. The device according to claim 10 , wherein the fourth electrode includes a second antiferromagnetic layer.

12. The device according to claim 1 , wherein
a thickness of the first non-magnetic metal layer is not less than 0.2 nm and not more than 2 nm, and
a thickness of the second non-magnetic metal layer is not less than 0.2 nm and not more than 2 nm.

13. The device according to claim 1 , wherein
the first non-magnetic metal layer includes at least one selected from the group consisting Ru, Cu, Au, W, and Mo, and
the second non-magnetic metal layer includes at least one selected from the group consisting Ru, Cu, Au, W, and Mo.

14. The device according to claim 1 , wherein
the first reproducing element portion further includes an first insulating portion provided between the first signal detecting portion and the first side shield and between the first side shield and the first electrode, and
the second reproducing element portion further includes a second insulating portion provided between the second signal detecting portion and the second side shield and between the second side shield and the third electrode.

15. The device according to claim 1 , wherein
the second electrode includes
a CoFe layer, and
a Ru layer,

a direction connecting the CoFe layer and the Ru layer is along the first direction.

16. The device according to claim 1 , wherein
the fourth electrode includes
a CoFe layer, and
a Ru layer,

a direction connecting the CoFe layer and the Ru layer is along the first direction.

17. The device according to claim 1 , wherein
the first side shield includes a first region contacting the second electrode,
the second side shield includes a second region contacting the fourth electrode,
an orientation of a magnetization in the first region is anti-parallel to an orientation of a magnetization in the second region.

18. The device according to claim 1 , wherein a distance between the first reproducing element portion and the second reproducing element portion is not less than 10 nm and mot more than 170 nm.

19. A magnetic reproducing method, comprising outputting an output signal according to either one of a first signal and a second signal, the first signal being obtained by reproducing information recorded on a first recording region of a magnetic recording medium by a first reproducing element portion, the second signal being obtained by reproducing the information recorded on the first recording region by a second reproducing element portion
wherein
the first reproducing element portion and the second reproducing element portion are included in a magnetic head,
the first reproducing element portion includes:
a first electrode,
a second electrode apart from the first electrode in a first direction,
a first signal detecting portion provided between the first electrode and the second electrode, and
a first side shield, at least a part of the first side shield overlapping the first signal detecting portion in a second direction crossing the first direction,

the second reproducing element portion includes:
a third electrode,
a fourth electrode apart from the third electrode in the first direction,
a second signal detecting portion provided

Assignees

• Toshiba Kk

Inventors

• Sugawara Katsuya
• Maeda Tomoyuki
• Yamada Kenichiro

Classifications

• G11B5/3912 Primary

  Arrangements in which the active read-out elements are transducing in association with active magnetic shields, e.g. magnetically coupled shields (G11B5/3916 takes precedence) · CPC title

• G11B5/486

  with provision for mounting or arranging electrical conducting means or circuits on or along the arm assembly · CPC title

• G11B15/12

  Masking of heads; {circuits for} Selecting or switching of heads between operative and inoperative functions {or between different operative functions or for selection between operative heads}; Masking of beams, e.g. of light beams {(track selection by moving the magnetic head G11B5/54)} · CPC title

• G11B19/02

  Control of operating function, e.g. switching from recording to reproducing · CPC title

• G11B15/02

  Control of operating function, e.g. switching from recording to reproducing · CPC title