TECHNIQUES TO REDUCE ADJACENT TRACK ERASURE

• US 20080024912A1
• Filed: 08/14/2007
• Published: 01/31/2008
• Est. Priority Date: 12/04/2003
• Status: Active Grant

• Current Assignee: Maxtor Corporation (Seagate Technology Holdings Plc)
• Original Assignee: Maxtor Corporation (Seagate Technology Holdings Plc)
• Inventors: Mallary, Michael, Benakli, Mourad
• Granted Patent: US 7,511,921 B2
• Time in Patent Office: Days
• US Class Current: 360/110
• CPC Class Codes: G11B 5/1278 specially adapted for magnetisations perpendicular to the surface of the record carrier
• CPC Class Codes: G11B 5/17 Construction or disposition of windings
• CPC Class Codes: G11B 5/1871 Shaping or contouring of the transducing or guiding surface
• CPC Class Codes: G11B 5/3116 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 Class Codes: G11B 5/3123 by using special coil configurations or conductors

Abstract

Techniques for reducing adjacent track erasure include: a bucking coil having a lower number of turns than the write coil for bucking out a portion of the field induced by the write coil; a hybrid solenoid coil that includes turns that are in a pancake arrangement and turns that are in a solenoid arrangement; a P2 write pole tip with an increasing amount of flare as the distance from the ABS increases; a notch along an edge of the ABS surface of the P1 write pole adjacent to a tooth that extends closest to the P2 write pole; a back notch adjacent to the tooth on the P1 write pole that has a width generally corresponding to the width of the tooth; and a layered structure on the pole tip of the P1 write pole adjacent to the tooth, the layers having at least one of decreasing amounts of saturation magnetization, decreasing amounts of permeability, or alternating layers of magnetic and nonmagnetic material, where the width of the magnetic and nonmagnetic layers is controlled or the characteristics of the magnetic layers are controlled with regard to saturation magnetization or magnetic permeability to effectively decrease the overall saturation magnetization or permeability.

Claims

1. A read/write head for a disk drive system, comprising:

a read transducer; and

a write transducer that is configured for longitudinal magnetic recording, the write transducer including;

a pair of write poles;

a write coil disposed between the pair of write poles, the write coil having n turns; and

a compensation coil disposed on an opposite side of the write poles from the read transducer, the compensation coil having m turns, the compensation coil inducing a magnetic field that opposes a magnetic field induced by the write coil;

wherein n is greater than m.

2. A read/write head as defined in claim 1, wherein n is at least two turns greater than m.

3. A read/write head as defined in claim 1, wherein n is at least three turns greater than m.

4. A read/write head as defined in claim 1, wherein n is greater than or equal to 5 and m is less than or equal to 2.

5. A read/write head as defined in claim 1, wherein the write coil and compensation coil are electrically connected together in series so that the identical current flows in each.

6. A read/write head for a disk drive system, comprising:

a read transducer; and

a write transducer including;

a pair of write poles, there being two and only two write poles;

a write coil disposed between the pair of write poles, the write coil having n turns; and

a compensation coil disposed on an opposite side of the write poles from the read transducer, the compensation coil having m turns, the compensation coil inducing a magnetic field that opposes a magnetic field induced by the write coil;

wherein n is greater than m.

7. A read/write head as defined in claim 6, wherein n is at least two turns greater than m.

8. A read/write head as defined in claim 6, wherein n is at least three turns greater than m.

9. A read/write head as defined in claim 6, wherein n is greater than or equal to 5 and m is less than or equal to 2.

10. A read/write head as defined in claim 6, wherein the write coil and compensation coil are electrically connected together in series so that the identical current flows in each.

11. A read/write head for a disk drive system, comprising:

a read transducer; and

a write transducer including;

a pair of write poles, and

a write coil having portions of turns disposed between the pair of write poles, a portion of the turns of the write coil being configured in a pancake arrangement and a portion of the turns of the write coil being configured in a solenoidal arrangement.

12. A read/write head as defined in claim 11, wherein the turns of the pancake portion generally lie in a single plane.

13. A read/write head as defined in claim 11, wherein the turns of the solenoid portion generally have the same diameter.

14. A read/write head as defined in claim 11, wherein the turns of the pancake portion generally lie in a single plane and the turns of the solenoid portion generally have the same diameter.

15. A read/write head as defined in claim 11, wherein a portion of each turn is disposed between the write poles.

16. A read/write head as defined in claim 15, wherein the read/write head has an air-bearing surface (ABS) facing toward an adjacent magnetic storage disk in the disk drive system, wherein the write transducer further includes a write yoke that magnetically connects the pair of write poles, wherein the turns that are configured in a pancake arrangement and that have portions of the turns that are disposed between the pair of write poles have these portions located further from the ABS than the portions disposed between the write poles of the turns that are configured in a solenoid arrangement.

17. A read/write head as defined in claim 11, wherein at least three turns of the write coil are configured in the pancake arrangement.

18. A read/write head as defined in claim 11, wherein at least three turns of the write coil are configured in the solenoidal arrangement.

19. A read/write head as defined in claim 11, wherein a first turn of the write coil that is configured in the pancake arrangement has a smaller diameter than a diameter of a second turn of the write coil that is configured in the pancake arrangement.

20. A read/write head as defined in claim 11, wherein the turns of the write coil that are configured in the solenoidal arrangement do not lie in a single plane.