Servo write timing generation in a multi-actuator disk drive

• US 6,735,032 B2
• Filed: 04/16/2001
• Issued: 05/11/2004
• Est. Priority Date: 04/16/2001
• Status: Expired due to Fees

• Current Assignee: Hitachi Global Storage Technologies Netherlands BV (Western Digital Corporation)
• Original Assignee: International Business Machines Incorporated (International Business Machines Corporation)
• Inventors: Dunn, George Anthony, Thomas, Scott Arthur
• Primary Examiner(s): Hudspeth, David
• Assistant Examiner(s): Figueroa, Natalia
• Application Number:
  US09/835,675
• Publication Number:
  US 20020149867A1
• Time in Patent Office: 1,121 Days
• Field of Search: 360/75, 360/51, 360/48, 360/78.12, 360/78.04, 360/78.14, 360/77.08, 360/31, 360/77.02, 360/77.07, 360/77.05
• US Class Current: 360/51
• CPC Class Codes: G11B 20/1403 characterised by the use of two levels
• CPC Class Codes: G11B 5/59633 Servo formatting G11B5/59627, G11B5/59677, G11B5/59683, G11B5/59688 take precedence

Abstract

A multi-actuator disk storage device has at least two actuators respectively mounting plural product heads. Servo writing is performed using the product heads themselves. A first servo write operation is performed that includes operating a product head of the first actuator as a first clock head to generate first clock reference information for the product heads of the second actuator, which are operated as servo write heads to perform servo writing of disk areas associated with the second actuator using the first clock reference information. To servo write disk areas associated with the first actuator, a second servo write operation is performed. This operation includes operating a product head of the second actuator as a second clock head to generate second clock reference information for the product heads of the first actuator, which are operated as a servo write heads to perform servo writing using the second clock reference information.

Claims

1. A method for performing servo writing in a multi-actuator disk storage device having at least two actuators respectively mounting plural product heads, comprising the steps of:

performing a first servo write operation that includes;

operating a product head of a first one of said actuators as a first clock head to generate first clock reference information;

operating the product heads of a second one of said actuators as servo write heads to perform servo writing of all disk areas associated with said second actuator using said first clock reference information and actuator self-positioning; and

performing a second servo write operation that includes;

operating a product head of said second actuator as a second clock head to generate second clock reference information;

operating the product heads of said first actuator as servo write heads to perform servo writing of all disk areas associated with said first actuator using said second clock reference information and actuator self-positioning.

2. A method in accordance with claim 1 wherein said clock reference information generating steps respectively include positioning said first and second clock heads at disk data area edges.

3. A method in accordance with claim 2 wherein said first and second clock heads are positioned by biasing the actuators which carry said clock heads against actuator crash stops or other positioning members.

4. A method in accordance with claim 2 wherein said first and second clock heads are positioned by servoing.

5. A method in accordance with claim 4 wherein said servoing is performed using pre-written timing information.

6. A method in accordance with claim 1 wherein said clock reference information generating steps respectively include controlling said first and second clock heads to write timing information to a disk area and thereafter read said timing information.

7. A method in accordance with claim 6 wherein said first servo write operation includes controlling said first clock head to write first timing information and said second servo write operation includes controlling said second clock head to write second timing information using said first timing information.

8. A method in accordance with claim 7 wherein said second clock head writes said second timing information in a predetermined tangential orientation relative to said first timing information to provide timing alignment between said actuators.

9. A method in accordance with claim 1 wherein said clock reference information generating steps respectively include controlling said first and second clock heads to read pre-written timing information.

10. A method in accordance with claim 1 wherein said disk drive includes more than two actuators and wherein:

said first servo write operation includes operating a product head of said first actuator as said first clock head while product heads of one or more remaining actuators perform servo writing; and

said second servo write operation includes operating a product head already used for servo writing as said second clock head while product heads of said first actuator and any remaining actuators perform servo writing.

11. A disk drive having multiple actuators respectively mounting plural product heads that read and write information on associated disk areas, at least two of said disk areas having first and second timing information respectively recorded thereon and other of said disk areas having servo sectors recorded thereon according to a servo writing method that comprises the steps of:

performing a first servo write operation that includes;

operating a product head of one of said actuators as a first clock head to generate first clock reference information;

operating the product heads of a second one of the actuators as servo write heads to perform servo writing of all disk areas associated with said second actuator using said first clock reference information and actuator self-positioning; and

performing a second servo write operation that includes;

operating a product head of said second actuator as a second clock head to generate second clock reference information;

operating the product heads of said first actuator as a servo write head to perform servo writing of all disk areas associated with said first actuator using said second clock reference information and actuator self-positioning.

12. A disk drive in accordance with claim 11 wherein said clock reference information generating steps respectively include positioning said first and second clock heads at disk data area edges.

13. A disk drive in accordance with claim 11 wherein said clock reference information generating steps respectively include controlling said first and second clock heads to write timing information to a disk area and thereafter read said timing information.

14. A disk drive in accordance with claim 13 wherein said first servo write operation includes controlling said first clock head to write first timing information and said second servo write operation includes controlling said second clock head to write second timing information using said first timing information.

15. A disk drive in accordance with claim 14 wherein said second clock head writes said second timing information in a predetermined tangential orientation relative to said first timing information to provide timing alignment between said actuators.

16. A disk drive in accordance with claim 11 wherein said clock reference information generating steps respectively include controlling said first and second clock heads to read pre-written timing information.

17. A disk drive in accordance with claim 11 wherein said disk drive includes more than two actuators and wherein:

said first servo write operation includes operating a product head of said first actuator as said first clock head while product heads of one or more remaining actuators perform servo writing; and

said second servo write operation includes operating a product head already used for servo writing as said second clock head while product heads or said first actuator and any remaining actuators perform servo writing.

18. A disk drive in accordance with claim 11 wherein said first and second clock heads are positioned by biasing the actuators which carry said clock heads against actuator crash stop members or other positioning members.

19. A disk drive in accordance with claim 11 wherein said first and second clock heads are positioned by servoing.

20. A disk drive in accordance with claim 19 wherein said servoing is performed using pre-written timing information.

21. A system for servo writing a multiple actuator disk file, comprising:

a storage disk assembly in said disk file;

a first actuator in said disk file mounting plural product heads to access a first portion of said storage disk assembly;

a second actuator in said disk file mounting plural product heads to access a second portion of said storage disk assembly;

a controller in said disk file;

a programmable data processor external to said disk file and in communication with said controller;

a servo write control program;

a first set of control program instructions for performing a first servowrite operation that includes;

operating a product head of said actuator as a first clock head to generate first clock reference information;

operating the second product heads of said second actuator as servo write heads to perform servo writing of all of said second disk portion using said first clock reference information and actuator self-positioning; and

a second set of control program instructions for performing a second servo write operation that includes;

operating a product head of said second actuator as a second clock head to generate second clock reference information;

operating the product heads of said first actuator as servo write heads to perform servo writing of all of said first disk portion using said second clock reference information and actuator self-positioning.