Method of measuring linear velocity of disk

摘要

A method of measuring a linear velocity of a rotating disk (12) on a disk drive system (11) wherein a rotation of a spindle motor (14) is controlled in accordance with a predetermined linear velocity, includes steps of: generating the predetermined linear velocity based on a signal reproduced from the disk (12) to control an initial rotation of the spindle motor (14); setting a pickup (16) in a position at a predetermined radius of the disk (12); measuring a one-revolution time required for one revolution of the disk (12) when the pickup (16) is set in the position and a subsequent rotation of the spindle motor (14) is controlled to keep the linear velocity of the disk (12) in accordance with the predetermined linear velocity; and determining the linear velocity of the disk (12) based on the measured one-revolution time and the predetermined radius.