Patent ID: 7106545

Claim:
A method of writing servo pattern data in a disk drive having a disk medium on which timing pattern data for determining writing timing is recorded, and a head with read/write head elements, the method comprising the steps of: moving the head to an initial position on the disk medium; writing, with the write head element, initial servo pattern data to the initial position based on the timing pattern data read by the read head element; performing additive servowriting operation in which additive servo pattern data is sequentially written in such a manner that first additive servo pattern data is written with the write head element that has been positioned based on the initial servo pattern data read by the read head element, and second additive servo pattern data is written based on the first additive servo pattern data that has been written; determining whether it is impossible to continue the additive servowriting operation; interrupting the additive servowriting operation when it has been determined that it is impossible to continue the additive servowriting operation; resuming the additive servowriting operation after moving the head to the position of the additive servo pattern data that has been written before the interruption; and deleting all or part of the additive servo pattern data that was being written at the time of the determination that it is impossible to continue the additive servowriting operation, wherein the resumption step changes writing timing of the write head element based on the timing pattern data after writing operation of the additive servo pattern data corresponding to one circuit of the disk medium has been interrupted in the middle of the operation and resumes writing operation of the additive servo pattern data from a position different from the interruption position in the disk circumferential direction.