Abstract: A microfabricated wobble motor with a positioning arm attached to the wobble motor rotor acts as a fine positioner with bidirectional movement. The primary application is a rotary actuator for the read/write head in a very small magnetic recording disk drive. An integrated head-arm assembly is attached at one end to the rotor of the wobble motor. The other end of the head-arm assembly has a head carrier that is maintained in contact with the disk. Head position error information is read from the disk and used to provide control signals to each of the stator elements. The stator elements are sequentially addressed by applying a voltage from a driver circuit. This causes the rotor to be electrostatically attracted to the activated stators, so that the rotor is movable bidirectionally. The read/write head can thus be moved bidirectionally to any of the data tracks on the disk and maintained on a desired data track for reading or writing data.

Abstract: A magnetic recording disk drive with a magnetoresistive (MR) read sensor or head has a shock and vibration detection circuitry responsive to a thermoresistive signal contained in the signal from the head. The MR head is heated by an electrical bias current and is supported on the head carrier near the surface of the disk. External shock or vibration to the disk drive alters the spacing between the carrier and the disk, which causes fluctuations in the head temperature due to cooling of the heated head by the disk. These temperature fluctuations are reflected in the signal from the head as a thermoresistive signal comprising modulation of a baseline voltage level. The shock detection circuitry compares positive and negative excursions of this thermoresistive signal with a predetermined threshold voltage level. When the threshold is exceeded, indicating an external shock or vibration in excess of an allowable limit, writing of data is inhibited.

Abstract: A contact recording disk file uses an integrated head-suspension assembly having a head carrier with a dual-layer wear pad for contacting the disk during read and write operations. The outer wear layer of the pad is relatively soft and wear prone compared to a harder and more wear-resistant inner layer. The outer wear layer wears away at a relatively rapid rate during initial wear-in of the head carrier. In this manner the head pole pieces, which extend into the wear pad, are rapidly put into contact with the disk, thereby compensating for initial misalignment of the wear pad with the surface of the disk. The inner wear layer then provides wear resistance over the life of the disk file. In the preferred embodiment, both the outer and inner wear layers are formed of essentially amorphous carbon doped with different amounts of hydrogen.