Patent ID: 7203019
Filing Date: 2007-04-10
Classification: G11B

Abstract:
1. A latch apparatus for latching an actuator arm assembly that positions a read/write head relative to a data storage disk of a disk drive, the latch apparatus comprising: a latch arm that is configured to be moved between a closed position that inhibits movement of the actuator arm assembly in a landing zone and an open position that does not inhibit movement of the actuator arm assembly in the landing zone; a coil that is configured to generate an electromagnetic force on the latch arm responsive to a coil current; a permanent magnet that is configured to generate a magnetic force on the latch arm that is substantially opposed to the electromagnetic force from the coil; and a latch control circuit that is configured to increase over a defined opening time period the coil current to at least an upper defined level to cause the coil to move the latch arm from the closed position to the open position, and to decrease over a defined closing time period the coil current to no more than a lower defined level to cause the permanent magnet to move the latch arm from the open position to the closed position, wherein the latch control circuit is further configured to reduce the coil current to no less than a defined minimum level until after the latch arm is expected to have reached the closed position after which the latch control circuit further reduces the coil current below the defined minimum level.