Abstract: An improved magnetic read/write head actuator assembly for use within a storage disk system that reduces average access time. The actuator assembly includes an actuator arm mounted on pivotal hub. A read/write head is supported at a distal end of the actuator arm such that the head is positioned in close proximity to a rotating magnetic storage disk. An actuator motor cooperates with the actuator arm to provide pivotal motion to the actuator arm about a central pivot axis. The actuator motor includes an asymmetric rotor winding connected to the actuator arm at an end opposite the distal end and an asymmetrical stator magnet structure that is statically mounted in close proximity to the asymmetric rotor winding. The actuator motor, further includes a flux conductive member that forms a closed flux path through the rotor winding and the asymmetrical stator magnet structure.

Abstract: A voice coil motor (VCM) driver has four field effect transistors connected to a motor coil as an H-bridge. A sense resistor in series with the coil and the H-bridge senses coil current. A feedback amplifier provides a feedback signal from a voltage developed across the sense resistor. A summing junction sums current command signals with the feedback signal. A transconductance loop compensation amplifier has an inverting input connected to the summing junction, has a non-inverting input connected to a reference level, and has an output control signal node. The control level is connected to control linear transconductance differential driver amplifiers including the four field effect transistors during a linear drive mode.

Abstract: An analog-to-digital converter circuit in a sampling data detection channel of a disk drive synchronously samples user data in the data track areas at a first quantization resolution and samples servo bursts from the spoke areas at a second quantization resolution effectively greater than said first quantization resolution. An offset circuit provides a predetermined analog offset signal to a combining circuit which combines it with an incoming analog signal to provide a composite signal during a spoke servo burst sampling interval. An analog-to-digital converter samples the composite signal during the servo spoke burst sampling interval, and synchronously samples the analog signal during a user data sampling interval. A digital averaging circuit averages the servo spoke samples over a predetermined averaging interval to provide averaged burst samples having increased bit resolution.

Abstract: A magnetic tape head actuator assembly has a stepper motor having a threaded output shaft and a bracket for supporting a tape head assembly. The bracket includes a pair of outwardly extending flanges. The flanges each have a bore, whereby the bores are axially aligned and dimensioned to accept the output shaft therethrough. The bracket further has an integral platform portion oriented normal to the threaded output shaft for mounting a tape head assembly. A threaded split nut positioned intermediate the bores is rigidly attached to the bracket and engages the threaded output shaft for movement of the bracket back and forth along the shaft. The nut further has an annular groove encircling its outer perimeter, wherein a circular spring positioned therein provides an inwardly directed compressive force on the nut.