Multi-track reader for improved signal to noise ratio

Patent metadata

Field	Value
Publication number	US-10127933-B2
Application number	US-201715674952-A
Country	US
Kind code	B2
Filing date	Aug 11, 2017
Priority date	Feb 28, 2014
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

A system according to one embodiment includes a magnetic head having a plurality of sensors arranged to simultaneously read at least three immediately adjacent data tracks on a magnetic medium, wherein none of the sensors share more than one lead with any other of the sensors. Such embodiment may be implemented in a magnetic data storage system such as a disk drive system, which may include a magnetic head, a drive mechanism for passing a magnetic medium (e.g., hard disk) over the magnetic head, and a controller electrically coupled to the magnetic head.

First claim

What is claimed is:

1. A magnetic head comprising:
a plurality of read sensors positioned along a track direction and spaced apart in a cross track direction that is perpendicular to the track direction;
a plurality of independent leads, wherein each of the plurality of read sensors is coupled to one of the plurality of independent leads;
at least one shared lead, wherein the at least one shared lead is coupled to at least two of the plurality of read sensors; and
a biasing layer associated with each of the plurality of read sensors in the cross track direction to provide magnetic stability to the plurality of read sensors,
wherein a width of the biasing layer is forty percent to fifty percent of a center to center track pitch of a magnetic medium.

2. The magnetic head of claim 1 , wherein the plurality of read sensors comprises a first read sensor, a second read sensor, and a third read sensor, and wherein a portion of the second read sensor overlaps with a portion of the first read sensor and a portion of the third read sensor in the cross track direction.

3. The magnetic head of claim 2 , wherein the second read sensor has a width in the cross track direction that is larger than a width of the first read sensor and a width of the third read sensor in the cross track direction.

4. The magnetic head of claim 2 , wherein a width of the first read sensor, the second read sensor, and the third read sensor is at least seventy percent of the center to center track pitch of the magnetic medium.

5. The magnetic head of claim 2 , wherein the first read sensor and the third read sensor are oriented along a common line in the cross track direction.

6. The magnetic head of claim 2 , wherein each of the first read sensor, the second read sensor, and the third read sensor are offset from one another in the track direction.

7. The magnetic head of claim 2 , wherein a spacing between the first read sensor and the second read sensor in the track direction, and between the third read sensor and the second read sensor in the track direction is less than about one hundred nanometers.

8. The magnetic head of claim 2 , wherein a spacing between the plurality of read sensors that are positioned along a common line in the cross track direction is less than one hundred percent of the center to center track pitch of the magnetic medium.

9. The magnetic head of claim 2 , wherein the plurality of independent leads comprises three independent leads, and wherein each of the first read sensor, the second read sensor, and the third read sensor is coupled to one of the three independent leads.

10. The magnetic head of claim 2 , wherein the first read sensor and the third read sensor are coupled to the at least one shared lead.

11. The magnetic head of claim 2 , wherein the first read sensor, the second read sensor, and the third read sensor are all coupled to the at least one shared lead.

12. The magnetic head of claim 1 , wherein the biasing layer is on either side of each of the plurality of read sensors in the cross track direction.

13. A system comprising:
a magnetic medium having a center to center track pitch; and
a magnetic head configured to simultaneously read at least three adjacent data tracks of the magnetic medium, the magnetic head comprising:
a plurality of read sensors positioned along a track direction and spaced apart in a cross track direction that is perpendicular to the track direction;
a plurality of independent leads, wherein each of the plurality of read sensors is coupled to one of the plurality of independent leads;
at least one shared lead, wherein the at least one shared lead is coupled to at least two of the plurality of read sensors; and
a biasing layer associated with each of the plurality of read sensors in the cross track direction to provide magnetic stability to the plurality of read sensors,
wherein a width of the biasing layer is forty percent to fifty percent of the center to center track pitch of the magnetic medium.

14. The system of claim 13 , further comprising a signal processing unit coupled to the plurality of independent leads and the at least one shared lead, wherein the signal processing unit is configured to at least one of apply waveform shaping, detect signals from the plurality of read sensors, differentiate between data read from the adjacent data tracks of the magnetic medium, and apply a timing offset to the signals from the plurality of read sensors.

15. The system of claim 13 , wherein the biasing layer is on either side of each of the plurality of read sensors.

16. The system of claim 13 , wherein each of the plurality of independent leads comprises at least one of W, Ta, Rh, Ru, and Cu.

17. The system of claim 13 , wherein a width of each of the plurality of read sensors is at least seventy percent of the center to center track pitch of the magnetic medium.

18. A magnetic head comprising:
a first read sensor configured to read data from a first data track of a magnetic medium associated with the magnetic head;
a second read sensor configured to read data from a second data track of the magnetic medium;
a third read sensor configured to read data from a third data track of the magnetic medium, wherein the first data track, the second data track, and the third data track are adjacent data tracks of the magnetic medium, and wherein the second read sensor is further configured to read the data from the first data track and the third data track;
a shared lead coupled to the first read sensor and the third read sensor;
a plurality of independent leads, wherein the first read sensor, the second read sensor, and the third read sensor are coupled to one of the plurality of independent leads; and
a biasing layer associated with the first read sensor, the second read sensor, and the third read sensor in the cross track direction to provide magnetic stability,
wherein a width of the biasing layer is forty percent to fifty percent of a center to center track pitch of the magnetic medium.

19. The magnetic head of claim 18 , further comprising a fourth read sensor coupled to the shared lead along with the first read sensor and the third read sensor.

20. The magnetic head of claim 19 , further comprising a fifth read sensor oriented along a first common line with the second read sensor in a cross track direction, and wherein the first read sensor, the third read sensor, and the fourth read sensor are oriented along a second common line in the cross-track direction.

Assignees

• Western Digital Tech Inc

Inventors

• Batra Sharat
• Coker Jonathan D
• Oenning Travis R

Classifications

• G11B20/10009 Primary

  Improvement or modification of read or write signals · CPC title

• G11B5/33

  Structure or manufacture of flux-sensitive heads, {i.e. for reproduction only; Combination of such heads with means for recording or erasing only}({Single head using magnetic domains for scanning G11B5/4946; multiple head for scanning G11B5/4907 and subgroups } ; general details therefor G11B5/133 - G11B5/255) · CPC title

• G11B5/3977

  from different information tracks · CPC title

• G11B5/3951 Primary

  the active elements being arranged on several parallel planes · CPC title

• G11B5/09

  Digital recording · CPC title