Method and apparatus for improving the performance of a disk drive

• US 7,430,091 B2
• Filed: 10/21/2005
• Issued: 09/30/2008
• Est. Priority Date: 10/21/2005
• Status: Expired due to Fees

• Current Assignee: Microsoft Corporation
• Original Assignee: Microsoft Corporation
• Inventors: Manasse, Mark Steven
• Primary Examiner(s): Olson; Jason C
• Application Number:
  US11/256,042
• Publication Number:
  US 20070091500A1
• Time in Patent Office: 1,075 Days
• Field of Search: 360/78.12
• US Class Current: 360/77.01
• CPC Class Codes: G11B 5/48 Disposition or mounting of heads or head supports relative to record carriers mounting of head within housing G11B5/105; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed driving of both record carriers and head G11B15/18; guiding record carriers G11B15/60; head selecting circuits G11B15/12
• CPC Class Codes: G11B 5/5578 Multiple actuators addressing the same disk, e.g. to improve data rate or access rate

Abstract

An implementation of a disk drive with improved efficiency where a read head supported by a first positioning component is provided and a write head supported by a second positioning component is also provided. By positioning the write head behind the read head at a predetermined angle, the disk drive can execute a “read-before-write” or “read-modify-by-XOR-write” operation by before the platter has rotated a full revolution.

Claims

1. A disk drive comprising:

one or more platters having a plurality of tracks;

a first head associated with associated with a surface of a platter;

a first subsystem that positions said first head;

a second head associated with said surface of said platter for writing on a data sector on said side of said platter;

a second subsystem that positions said second head on the same track as the first head and phased at an angle from the first head based upon a determination of an optimal angular separation as measured from the center of the platter;

wherein the optimal angle of separation is determined based upon a rotational speed of said one or more platters and a time that it takes to reduce oscillations during a settle phase to effectively transfer data from said track, whereby the second head is able to write on the same data sector read by said first head before the platter has completed a full revolution.

2. The disk drive of claim 1 wherein said first subsystem that positions said first head comprises an actuator arm assembly to position said first head.

3. The disk drive of claim 1 wherein said second subsystem that positions said second head comprises an actuator arm that pivots around a pivot point.

4. The disk drive of claim 1 where said first subsystem that positions the first head comprises a sliding mechanism.

5. The disk drive of claim 1 wherein said first head and second head are capable of reading and writing on said platter.

6. The disk drive of claim 1 further comprising a controller responsive to a read-before-write instruction, said controller causing the first subsystem that positions the first head to move the first head to the sector where a datum to be read is positioned and causing the second subsystem to position the second head to write a datum in accordance with the read-before-write instruction.

7. The disk drive of claim 1 further comprising a controller responsive to a read-modify-by- XOR-write instruction, said controller causing the first subsystem to move the first head to the sector where a datum to be read is positioned and causing the second head to write a datum in accordance with the read-modify-by- XOR-write instruction.

8. The disk drive of claim 1 further comprising a controller responsive to an XOR-read-before write instruction, said controller causing the first subsystem to move the first head to the sector where a datum to be read is positioned and causing the second head to write the XOR of the datum to be read, a specified value, or a computed value.

9. A disk drive comprising:

a spindle;

at least one platter rotatably mounted on said spindle, said planer having a plurality of tracks;

a first subsystem that reads information on a sector in a track on said platter

a second subsystem that writes information on said sector, wherein said second subsystem is disposed along the same radius as the first subsystem at an angle based upon a determination of an optimal angular separation, wherein said optimal angular separation is determined based upon a rotational speed of said at least one platter and a time it takes to reduce oscillations during a settle phase to effectively transfer data from said track.

10. The disk drive of claim 9 wherein said first subsystem that reads information comprises a positioning component;

a reading head mounted on said positioning component and a controller that controls the movement of the positioning component.

11. The disk drive of claim 9 wherein said second subsystem that writes comprises a positioning component;

a writing head mounted on said positioning component and a controller that controls the movement of the positioning component.

12. The disk drive of claim 11 wherein said positioning component comprises a pivotable arm.

13. The disk drive of claim 11 wherein said positioning component comprises a sliding assembly.

14. A method of reading a first datum and writing second datum in a sector on a track on a platter comprising:

reading the first datum using a first head;

moving a second head to the same track on which the sector containing the first datum is located, said second head being positioned at an angle based upon a determination of an optimal angular separation , wherein said optimal angle of separation is determined from a rotational speed of said one or more platters and time that it takes to reduce oscillations during a settle phase to effectively transfer data from said track , wherein the determination comprises a product of the rotational speed and the time that it takes to reduce oscillations; and

causing the write head to write the second datum on the same sector as the first datum.

15. The method of claim 14 further comprising performing a calculation on said first datum to derive the second datum.

16. The method of claim 14 further comprising:

providing a read-before-write instruction to a disk drive controller;

providing a read instruction to a positioning mechanism for the first head; and

moving said first head to a location proximate to the sector where the first datum is to be read.

17. The method of claim 16 further comprising moving said second head to a location on the same track as the sector where the first datum to be read is located, and providing a write instruction to said second head.