Multiplexing servo tracking signals in a disk drive

• US 6,384,998 B1
• Filed: 08/17/1999
• Issued: 05/07/2002
• Est. Priority Date: 08/17/1999
• Status: Expired due to Fees

• Current Assignee: Hitachi Global Storage Technologies Netherlands BV (Western Digital Corporation)
• Original Assignee: International Business Machines Corporation
• Inventors: Price, Kirk Barrows, Yu, Mantle Man-Hon
• Primary Examiner(s): FABER, ALAN
• Application Number:
  US09/376,263
• Time in Patent Office: 994 Days
• Field of Search: 360/51, 360/31, 360/78, 360/14, 360/75, 360/61, 360/63, 360/77.05, 360/77.02, 360/77.07, 360/77.08
• US Class Current: 360/51
• CPC Class Codes: G11B 21/106 on disks

Abstract

A method, apparatus, and article of manufacture for controlling a disk drive with multiple VCMs is disclosed. The apparatus comprises a first disk storage surface and a second disk storage surface. The first disk storage surface has a plurality of first data segments and a plurality of first servo track segments interspersed therebetween, and is readable and writeable by a first head controllable according to a first servo track signal read from at least one of the first servo track segments. The second disk storage surface has a plurality of second data segments and a plurality of second servo track segments interspersed therebetween, and is readable and writeable a second head separately controllable from the first head according to a second servo track signal read from at least one of the plurality of second servo track segments. The first and second servo track signals are distinguishable by a servo signal characteristic, which allows a single signal transmittable on a single wire to convey the required servo track information to all of the heads.

Claims

1. A method of providing a track signal for each of a plurality of separately-controllable disk drive heads, each servicing an associated disk storage surface having a plurality of data segments and servo track segments storing a servo track signal interspersed therebetween, the method comprising the steps of:

reading the disk storage surfaces with each disk drive head in parallel to generate a servo track signal for each head, wherein the servo track signal from each head is distinguishable from the servo track signal for other heads by a servo signal characteristic; and

combining the servo track signals from each head into a single servo track signal.

2. The method of claim 1, further comprising the step of separating the servo track signals according to the servo signal characteristic.

3. The method of claim 2, further comprising the step of providing the each separated servo track signal to a servo motor associated with each respective head.

4. The method of claim 1, wherein the servo signal characteristic is a servo burst pattern.

5. The method of claim 1, wherein each servo signal is a servo timing pattern such that each servo signal is temporally displaced from other servo signals.

6. The method of claim 1, further comprising the steps of:

accepting a command comprising a head selection and an operation selection selected from a group comprising a write operation and a read operation;

writing input data to one of the disk storage surfaces according to the head selection when the operation is a write operation; and

reading output data from one of the disk storage surfaces according to the head selection, and providing the output data to an output data port when the operation is a write operation.

7. A program storage device, readable by a computer, tangibly embodying at least one program of instructions executable by the computer to perform method steps of providing a track signal for each of a plurality of separately-controllable disk drive heads, each servicing an associated disk storage surface having a plurality of data segments and servo track segments storing a servo track signal interspersed therebetween, the method steps comprising the steps of:

reading the disk storage surfaces with each disk drive head in parallel to generate a servo track signal for each head, wherein the servo track signal from each head is distinguishable from the servo track signal for other heads by a servo signal characteristic; and

combining the servo track signals from each head into a single servo track signal.

8. The program storage device of claim 7, wherein the method steps further comprise the method step of separating the servo track signals according to the servo signal characteristic.

9. The program storage device of claim 8, wherein the method steps further comprise the step of providing the each separated servo track signal to a servo motor associated with each respective head.

10. The program storage device of claim 7, wherein the servo signal characteristic is a servo burst pattern.

11. The program storage device of claim 7, wherein each servo signal is a servo timing pattern such that each servo signal is temporally displaced from other servo signals.

12. The program storage device of claim 7, wherein the method steps further comprise the steps of:

accepting a command comprising a head selection and an operation selection selected from a group comprising a write operation and a read operation;

writing input data to one of the disk storage surfaces according to the head selection when the operation is a write operation; and

reading output data from one of the disk storage surfaces according to the head selection, and providing the output data to an output data port when the operation is a write operation.