Systems and methods for repairable servo burst patterns
View Patent ↗The misplacement of a servo burst during a servowriting or self-servowriting process can be corrected by erasing and re-writing that burst. A servo pattern can be selected that has sufficient radial separation between bursts such that if a burst is re-written and trimmed there should be no damage to adjacent bursts. The radial separation can be selected to be greater than the width of the appropriate write element in order to allow for some misplacement of the element during the erasing and/or re-writing of the misplaced burst. Alternatively, a batch writing approach can be used to minimize the time needed to re-write misplaced bursts. In addition, WORF information of a track can be saved in memory for future servowriting and/or can be utilized to calculate a threshold for identifying servo bursts to be repaired. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.
1. A method to support repairable servowriting comprising:
servowriting a final servo pattern on one or more servo tracks on a surface of a medium, wherein the final servo pattern includes one or more servo bursts;
identifying at least one misplaced servo burst in the final servo pattern based on the final servo pattern;
repairing the at least one misplaced servo burst or its boundaries; and
adjusting a radial separation between any two adjacent bursts in the servo pattern by:
extending the servo pattern in the circumferential dimension via inserting at least one additional burst in the servo pattern; and
servowriting the at least one additional burst on a separate servo track in the one or more servo tracks.
2. The method according to claim 1 , wherein repairing the at least one misplaced servo burst includes not damaging an adjacent servo burst in the final servo pattern.
3. The method according to claim 1 , further comprising:
servowriting the final servo pattern via a read and/or write element of a read/write head.
4. The method according to claim 1 , further comprising:
servowriting the final servo pattern in the direction either from OD toward ID or from ID toward OD.
5. The method according to claim 1 , further comprising:
servowriting and/or repairing the final servo pattern based on a reference pattern.
6. The method according to claim 1 , further comprising:
identifying the at least one misplaced servo burst in the final servo pattern via at least one of servoing on and demodulating the final servo pattern.
7. The method according to claim 1 further comprising:
repairing the at least one misplaced servo burst by at least one of:
(1) trimming the at least one misplaced servo burst;
(2) erasing the at least one misplaced servo burst;
(3) writing a new servo burst in a position intended for the at least one misplaced servo burst on one of the servo tracks; and
(4) writing and trimming a new servo burst in a position intended for the at least one misplaced servo burst on one of the servo tracks.