Method and apparatus for providing positional information on a disk

• US 6,982,849 B2
• Filed: 09/13/2001
• Issued: 01/03/2006
• Est. Priority Date: 09/14/2000
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Chu, Sang Hoon, Choi, Soo Il, Nguyen, Tung, Shim, Jun Seok, Yu, Seong Hwan, Lee, Kang Seok
• Primary Examiner(s): Hudspeth, David
• Assistant Examiner(s): TZENG, FRED
• Application Number:
  US09/952,684
• Publication Number:
  US 20030048567A1
• Time in Patent Office: 1,573 Days
• Field of Search: 360/50, 360/77.08, 360/51, 360/54, 360/77.06, 360/75, 360/48, 360/78.07
• US Class Current: 360/77.08
• CPC Class Codes: G11B 27/3027 used signal is digitally coded
• CPC Class Codes: G11B 5/59633 Servo formatting G11B5/59627, G11B5/59677, G11B5/59683, G11B5/59688 take precedence
• CPC Class Codes: G11B 5/59688 Servo signal format patterns or signal processing thereof, e.g. dual, tri, quad, burst signal patterns

Abstract

The present invention is a method and apparatus for positioning a read/write head in a hard disk drive. The method comprises providing a disk having a at least one side with a plurality of tracks, where each of the tracks has a servo field with servo bits. The servo bits are read to provide a position signal for positioning a read/write head. The method determines a difference in position between an initial and a subsequent position of the read/write head on a track, where the subsequent location occurs after the read/write head has moved one revolution from the initial position on the track. The initial and subsequent positions are offset laterally. The method generates a compensation signal based on the initial position, the subsequent position and the difference. The position signal and the compensation signal are combined to provide a compensated position signal for positioning the read/write head. Various embodiments are described.

Claims

1. A method for positioning a read/write head in a hard disk drive, comprising:

a) providing a disk having at least one side with a plurality of tracks, each of said tracks having a servo field, said servo field having servo bits;

b) reading said servo bits to provide a position signal for positioning a read/write head;

c) determining a magnitude of a difference in position between an initial and a subsequent position of the read/write head on a track, said subsequent location to occur after said read/write head has moved one revolution from said initial position on said track, said initial and subsequent position being offset laterally; and

d) generating a compensation signal based on said initial position, said subsequent position and said difference;

e) combining said position signal and said compensation signal to provide acompensated position signal for positioning said read/write head.

2. The method as recited in claim 1, wherein c) further comprises:

determining a sector for initiating gap compensation based on said initial and subsequent positions.

3. The method as recited in claim 2, wherein c) further comprises determining if a difference between said initial position and half of a length of said gap compensation is greater or equal to zero;

if so, said sector for initiating gap compensation is equal to a difference between said initial position and half of a length of said gap compensation;

otherwise, said sector for initiating gap compensation is equal to a sum of said difference between said initial position and half of a length of said gap compensation, and a total number of sectors on said track.

4. The method am recited in claim 3, wherein in d) said compensation signal is further based on a current position of said read/write head and said length of said gap compensation.