Abstract: An actuator arm with suppressed arm fluttering is provided. On a main surface of each actuator arm in an actuator arm unit there are formed a rigid area which extends centrally in the longitudinal direction and flow uniformizing areas which are each formed in a substantially flat shape extending longitudinally in adjacency to the rigid area and which are thinner than the rigid area. A balance aperture is not formed in the portion where the flow uniformizing areas and the rigid area are formed, to diminish arm fluttering. Instead of a balance aperture, the flow uniformizing areas also exhibit the effect of reducing the weight of the actuator arm.

Abstract: One feature of the invention is to support a wiring structure on a side surface of an actuator arm used in a magnetic disk device so as not to allow fluttering to occur. In one embodiment, a wire support member 102a used in a magnetic disk device includes a protruding wall 108a provided with an opposing surface facing a wiring structure 90a and protruding in a width direction, and a protruding wall 110a provided with an opposing surface facing the wiring structure 90a and protruding in a width direction. The wire support member 102a is provided with a fixing area for accommodating the wiring structure between the opposing surface of the protruding wall 108a and the opposing surface of the protruding wall 110a. The wire support member 102a is further provided with an open area adjoining the fixing area at a longitudinal end portion of the protruding wall and includes protruding walls 328, 330, 332 each having an opposing surface facing the wiring structure.

Abstract: An active control mechanism and method for stabilizing a servo-controlled actuator system such as an actuator system in a data recording disk drive by compensating the vibrational modes of the actuator's arm assembly. The control mechanism has a sensing arrangement which can include one or more individual sensors attached to the actuator at locations where they generate signals in phase with the vibrational modes, and especially with all the low-frequency major vibrational modes, of the arm assembly. A control mechanism derives from the signals an adjustment signal consisting of three corrective terms—a stiffening correction, an active damping correction, and an inertia correction by a phase correction. Furthermore, high-frequency out-of-phase modes can be stabilized by appropriately shifting the phase of the signals. The adjustment signal is used in the feedback control loop to stabilize the actuator system.

Abstract: To provide a piezoelectric sensor that never sacrifices work properties such as when a lead wire is to be soldered to one of a pair of electrodes of a piezoelectric sensor, and the other electrode is to be bonded and fixed to a predetermined member with an adhesive, and to bond the ground electrode of the piezoelectric sensor to the conductive portion of the object member with an adhesive so as to be fixed and connected electrically, thereby preventing a short-circuit that might occur between the two electrodes due to extruded and stuck adhesive, and to provide an easier method for testing whether or not the ground electrode is connected electrically to the conductive portion of the object member. A piezoelectric sensor has two electrodes that are formed with different materials appropriate for soldering and bonding by an adhesive. The ground electrode of the piezoelectric sensor is bonded to the object member with a non-conductive adhesive so as to be connected electrically.

Abstract: A stator magnet according to a first embodiment of the present invention forms a voice coil motor with a closed coil. The closed coil is supported by an actuator arm in a rotatable manner and at a predetermined rotation angle. The closed coil has first and second side edges that extend along different lines in radial directions whose center is a center of rotation of the actuator arm. It also has an outer edge that connects edges of outer sides of the first and second side edges with viewed from the radial direction, and extends along an arc whose center is the center of rotation. A first magnetic pole region is located within a moving area of the first side edge to act on the first side edge. A second magnetic pole region is located within a moving area of the second side edge to act on the second side edge. The polarity of the second magnetic pole region is opposite to the polarity of the first magnetic pole region.