Head with multiple readers configured for reading interlaced magnetic recording tracks

• US 10,068,597 B1
• Filed: 01/17/2018
• Issued: 09/04/2018
• Est. Priority Date: 01/17/2018
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Jury, Jason Charles, Granz, Steven Douglas
• Primary Examiner(s): Hindi, Nabil
• Application Number:
  US15/873,160
• Time in Patent Office: 230 Days
• Field of Search: 360 7706, 360 7808, 360 50, 360 64
• CPC Class Codes: G11B 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence
• CPC Class Codes: G11B 5/3948 the sensitive elements being active read-out elements
• CPC Class Codes: G11B 5/3967 Composite structural arrangements of transducers, e.g. inductive write and magnetoresistive read G11B5/3906 takes precedence
• CPC Class Codes: G11B 5/4886 relative to rotating disc
• CPC Class Codes: G11B 5/5526 Control therefor; circuits, track configurations or relative disposition of servo-information transducers and servo-information tracks for control thereof G11B5/556 takes precedence
• CPC Class Codes: G11B 5/59688 Servo signal format patterns or signal processing thereof, e.g. dual, tri, quad, burst signal patterns

Abstract

First tracks of a disk are read via a first read transducer. The first read transducer has a first crosstrack width and a first shield-to-shield spacing that are optimized to read a first track width and a first linear bit density of the first tracks. Second tracks interlaced between the first tracks are read via a second read transducer. The second read transducer has a second crosstrack width different from the first crosstrack width and second shield-to-shield spacing different than the first shield-to-shield spacing. The second crosstrack width and the second shield-to-shield spacing are optimized to read a second track width different from the first track width and a second linear bit density different from the first linear bit density.

Claims

1. An apparatus, comprising:

a read head, comprising;

a first read transducer comprising a first crosstrack width and a first shield-to-shield spacing that are optimized to read a first track width and a first linear bit density;

a second read transducer comprising a second crosstrack width different from the first crosstrack width and second shield-to-shield spacing different than the first shield-to-shield spacing, the second crosstrack width and the second shield-to-shield spacing optimized to read a second track width different from the first track width and a second linear bit density different from the first linear bit density; and

a controller coupled to the read head and operable to perform;

selecting the first read transducer for reading a first set of tracks having the first track width and the first linear bit density; and

selecting the second read transducer for reading a second set of tracks interlaced between the first set of tracks, the second set of tracks having the second track width and the second linear bit density.

2. The apparatus of claim 1, wherein the first and second tracks are respective top and bottom tracks in an interlaced magnetic recording arrangement.

3. The apparatus of claim 2, wherein the first and second read transducers have respective first and second widths that are respective first and second percentages of magnetic widths of the top and bottom tracks, the first percentage being less than the second percentage.

4. The apparatus of claim 3, wherein the first percentage improves bit transition times when reading the top tracks due to rounding of bit transitions that are written using heat-assisted magnetic recording.

5. The apparatus of claim 2, further comprising a third read transducer coupled to read the bottom tracks simultaneously with the second transducer, signals from the second and third transducers being combined using multiple signal/sensor magnetic recording read channel to read the bottom tracks.

6. The apparatus of claim 5, wherein one of the second and third read transducers is aligned in a downtrack direction with the first read transducer.

7. The apparatus of claim 1, wherein the first and second read transducers are aligned in a downtrack direction on the read head, and separated a cross-track distance that is greater than a track pitch of a recoding medium upon which the first and second tracks are recorded.

8. The apparatus of claim 1, wherein the first and second read transducers are separated by a cross track distance that allows the first and second read transducers to read adjacent ones of the first and second tracks.

9. The apparatus of claim 1, wherein the first and second read transducers have first and second sensor heights in a direction perpendicular to an air-bearing surface of the readers, the first and second sensor heights optimized to read the respective first and second track widths and the respective first and second linear bit densities.

10. The apparatus of claim 1, wherein the first and second read transducers have first and second sensor layer thicknesses, the first and second sensor layer thicknesses optimized to read the respective first and second track widths and the respective first and second linear bit densities.

11. The apparatus of claim 1, wherein the first and second read transducers have first and second side shield widths, the first and second sensor layer widths optimized to read the respective first and second track widths and the respective first and second linear bit densities.

12. A method, comprising:

reading first tracks via a first read transducer, the first read transducer comprising a first crosstrack width and a first shield-to-shield spacing that are optimized to read a first track width and a first linear bit density of the first tracks; and

reading second tracks interlaced between the first tracks via a second read transducer, the second read transducer comprising a second crosstrack width different from the first crosstrack width and second shield-to-shield spacing different than the first shield-to-shield spacing, the second cross-track width and the second shield-to-shield spacing optimized to read a second track width different from the first track width and a second linear bit density different from the first linear bit density.

13. The method of claim 12, wherein the first and second tracks are respective top and bottom tracks in an interlaced magnetic recording arrangement.

14. The method of claim 13, wherein the first and second read transducers have respective first and second widths that are respective first and second percentages of magnetic widths of the top and bottom tracks, the first percentage being less than the second percentage, and wherein the first percentage improves bit transition times when reading the top tracks due to rounding of bit transitions that are written using heat-assisted magnetic recording.

15. The method of claim 13, further comprising:

reading the bottom tracks via a third read transducer coupled to read the bottom tracks simultaneously with the second transducer; and

combining the signals from the second and third transducers via a multiple signal/sensor magnetic recording read channel to read the bottom tracks.

16. An apparatus, comprising:

a head comprising at least one write transducer and first and second read transducers;

the first read transducer comprising a first crosstrack width and a first shield-to-shield spacing that are optimized to read a first track width and a first linear bit density, the second read transducer comprising a second crosstrack width different from the first crosstrack width and second shield-to-shield spacing different than the first shield-to-shield spacing, the second crosstrack width and the second shield-to-shield spacing optimized to read a second track width different from the first track width and a second linear bit density different from the first linear bit density; and

a controller coupled to the head and configured to;

record top and bottom interlaced magnetic recording tracks, the top tracks recorded at the first track width and the first linear bit density, the bottom tracks recorded at the second track width and the second linear bit density; and

read the top tracks via the first reader and read the bottom tracks via the second reader.

17. The apparatus of claim 16, wherein the first and second read transducers have respective first and second widths that are respective first and second percentages of magnetic widths of the top and bottom tracks, the first percentage being less than the second percentage.

18. The apparatus of claim 17, wherein the first percentage improves bit transition times when reading the top tracks due to rounding of bit transitions that are written using heat-assisted magnetic recording.

19. The apparatus of claim 16, further comprising a third read transducer coupled to read the bottom tracks simultaneously with the second transducer, signals from the second and third transducers being combined using multiple signal/sensor magnetic recording read channel to read the bottom tracks.

20. The apparatus of claim 19, wherein one of the second and third read transducers is aligned in a downtrack direction with the first read transducer.