Contact start/stop disk drive with minimized head-disk wear in textured landing zone

摘要

A contact start/stop (CSS) magnetic recording disk drive has a highly textured head easier landing zone on the disk and uses a start/stop precedure that minimize both the time the carrier is in contact with the landing zone and the disk rotational speed during contact. The disk landing zone is textured with a pattern of laser-induced bumps that define a surface higher than the surface of the disk data region. At disk drive start-up and power-down, the head carrier exits and enters the landing zone at a predetermined disk rotational speed selected such that the air-bearing surface of the head carrier is still in contact with the surface of the landing zone but is flying in the data region. This limits the amount of time the carrier spends in contact with the textured surface and minimizes the disk speed when it is in contact. The reduced time and speed of carrier-disk contact in the landing zone improves the landing zone durability for any given texture level, which allows a larger level of texturing (and therefore lower stiction) to be used while maintaining adequate landing zone durability (number of CSS cycles without failure). Disk drive actuator control circuitry for start-up and actuator retract circuitry for power-down permit the head carrier to enter the disk data region while flying, even though the disk is not rotating at full speed and thus head servo positioning information is unavailable, and to exit the disk data region only when the disk has decreased to a speed at which the carrier is just capable of flying.