Abstract: An approach to a reduced-head hard disk drive (HDD) involves an actuator elevator subsystem that includes a ball screw cam assembly with an axial flux permanent magnet (AFPM) motor affixed to a cam screw to drive rotation of the screw, which drives translation of an actuator arm assembly so that a corresponding pair of read-write heads can access different magnetic-recording disks of a multiple-disk stack.

Abstract: Rotational latency is reduced in a standard conventional form factor HDD system by replacing, for example—the prior art rotary arm actuator of a conventional HDD, with one or more belts and pulleys and one or more read/write heads mounted on, or otherwise associated with the belts. Multiple scaled iterations facilitate energy savings and power optimized systems, without compromise to data access performance.

Abstract: Approaches to reducing the natural frequency of a voice coil motor (VCM) in a hard disk drive include configuring one or both of the yokes with at least one mating structure that comprises a step feature that partitions the mating structure into a contact surface and a recessed surface, where the contact surface is toward the outer area of the mating structure and contacts a corresponding mating structure of the other yoke and the recessed surface is toward the inner area of the mating structure and does not contact with the corresponding mating structure of the other yoke. Consequently, the distance between the fixed points is increased, which reduces the natural frequency and thus the resonance of the VCM assembly.

Abstract: The invention provides a position control system comprising a moving portion that is movable, a position-detection portion that detects a position of the moving portion, a drive portion that applies driving force to the moving portion thereby moving the moving portion, a control portion that controls the driving force of the drive portion, and an input portion for inputting a drive target position for the moving portion, characterized in that the control portion is operable to determine the driving force to be applied to the drive portion based on a correction coefficient acquired based on a first deviation that is a difference between the drive target position inputted into the input portion and the reference position, and a second deviation that is a difference between a position detected by the position-detection portion and the drive target position inputted into said input portion.

Abstract: A method of assembling a head stack assembly (HSA) includes securing a flex cable to an actuator including an actuator arm having a side slot with a slot end. A first head gimbal assembly (HGA) is attached to the actuator arm. The first HGA includes a first laminated flexure having a first flexure tail with a first raised region that includes an out-of-plane bend. The first raised region is squeezed while inserting the first flexure tail partially within the side slot with the first raised region adjacent the slot end. The first raised region is allowed to expand into contact with the side slot adjacent the slot end. The first flexure tail is electrically connected to the flex cable.

Abstract: This application discloses a hard disk drive using a self-resonant frequency band of a Voice Coil Motor far above its operational frequency band to predict Rapid Off Track events before its head stack assembly can deliver the disruption to the slider writing a track. A circuit board and/or an integrated circuit are disclosed in various embodiments to predict the ROT events using the self-resonant frequency band and/or to respond to the prediction to suppress the slider writing.

Abstract: A system for implementing current shaping for retract of a voice coil motor (VCM) includes drive circuitry coupled to drive the VCM according to a logic state of the system. Current shaping circuitry is configured to temporarily decrease the bandwidth of a VCM transconductance loop in response to a control signal. The transconductance loop includes at least the VCM, the current shaping circuitry and the drive circuitry. The system also includes logic configured to provide the control signal at an end portion a drive logic state to enter a current shaping logic state as a transition from the drive logic state to a floating logic state to reduce current through the VCM such that acoustic emissions from the VCM are mitigated during the retract.

Abstract: This application discloses a hard disk drive using a self-resonant frequency band of a Voice Coil Motor far above its operational frequency band to predict Rapid Off Track events before its head stack assembly can deliver the disruption to the slider writing a track. A circuit board and/or an integrated circuit are disclosed in various embodiments to predict the ROT events using the self-resonant frequency band and/or to respond to the prediction to suppress the slider writing.

Abstract: A disk for a hard disk drive. The disk includes a first magnetic layer supported by a substrate and an intermediate layer adjacent to the first magnetic layer. The disk also includes a second magnetic layer that is adjacent to the intermediate layer and includes barium. The barium second magnetic layer has a mechanical hardness so that a protective layer such as COC is not required for the disk.

Abstract: A system for implementing current shaping for retract of a voice coil motor (VCM) includes drive circuitry coupled to drive the VCM according to a logic state of the system. Current shaping circuitry is configured to temporarily decrease the bandwidth of a VCM transconductance loop in response to a control signal. The transconductance loop includes at least the VCM, the current shaping circuitry and the drive circuitry. The system also includes logic configured to provide the control signal at an end portion a drive logic state to enter a current shaping logic state as a transition from the drive logic state to a floating logic state to reduce current through the VCM such that acoustic emissions from the VCM are mitigated during the retract.

Abstract: A method of coupling a voice coil motor to a bowl-type base plate of a hard disk drive is described for a hard disk drive including a voice coil motor having a coil coupled to a rear end portion of an actuator arm, an upper yoke and a lower yoke provided at upper and lower portions of the coil respectively, a bowl-type base plate having a plurality of flattened structures for fastening the lower yoke in a position relative to the bowl-type base plate and a countersink formed in the lower yoke.

Abstract: A data storage device is made by molding a portion of a motor into a first enclosure member, and then coupling the first enclosure member to a second enclosure member to define an interior environment for other data storage device components.

Abstract: The present invention provides a VCM driver realizing low power consumption and high accuracy and a PWM amplifier compensating a dead time distortion. A phase compensator, a ?S modulator receiving an output signal of the phase compensator and converting the output signal to a control code of predetermined bits, a PWM modulator receiving the control code to produce a PWM signal, and an output circuit receiving the PWM signal to drive a voice coil constitute a forward path. A sense amplifier sensing a current of the voice coil, an ADC receiving an output signal of the sense amplifier, a low-pass filter receiving an output signal of the ADC, and a decimation filter receiving an output signal of the low-pass filter constitute a feedback path. An output signal of the decimation filter is fed back to the input side of the phase compensator to form a major feedback loop having a first-order characteristic loop gain.

Abstract: Embodiments of the invention relate to techniques to remove a defective head gimbal assembly (HGA) from a head stack assembly and replace the defective HGA with a good one without allowing any good HGAs to be damaged. In one embodiment, a volatile alcohol solvent is moved by gravity from a holder included in a reworking tool provided for a reworking jig to a shearing edge of a cartridge type edge mounted in the holder. The alcohol solvent is thereby deposited on the shearing edge in a drop-like shape through surface tension. The cartridge type edge is made to slide on a surface of an actuator arm and is inserted in a gap between contacting surfaces of a mount plate and the actuator arm. This assigns the drop-like alcohol solvent a function as a lubricant. Possible vibration can therefore be prevented from being transmitted through a carriage to other HGAs.

Abstract: Embodiments of the present invention provide a rotating disk storage device adopting a thin yoke structure. In one embodiment, the yoke structure of a voice coil motor includes a base of a casing formed from a ferromagnetic material; an auxiliary yoke disposed so as to be magnetically coupled to the base; a magnet disposed so as to be magnetically coupled to a front surface of the auxiliary yoke; and a main yoke provided with yoke legs magnetically coupled to the auxiliary yoke and an opposing surface that confronts a front surface of the magnet. In addition, a yoke gap is defined between the opposing surface and the front surface of the magnet. The base and the auxiliary yoke form a magnetic path, which allows a dedicated yoke on a lower portion to be eliminated.

Abstract: The upper voice coil motor magnet assembly (64a?) of a disk drive (10?) is magnetically aligned with the lower voice coil motor magnet assembly (64b?) using an alignment fixture (126). The alignment fixture (126) engages the upper voice coil motor magnet assembly (64a?) and lifts the same into a suspended position above the lower voice coil motor magnet assembly (64b?). In this suspended condition, the alignment fixture (126) allows the magnetic field to move the upper voice coil motor magnet assembly (64a?) within the horizontal dimension to a magnetically aligned position with the lower voice coil motor magnet assembly (64b?). Thereafter, the alignment fixture (126) lowers the upper voice coil motor magnet assembly (64a?) to a position where the same is again supported above the lower voice coil motor magnet assembly (64b?).

Abstract: A system for positioning a read/write head having a voice coil suitable for coarse control and a piezoelectric transducer (PZT) suitable for fine control. A voice coil control signal and a PZT control signal are generated from a position-indicative signal, both receiving power via a shared supply having a nominal rectified voltage V1. In a preferred method, control signals are both applied to the voice coil and PZT when amplified so that each has a saturation voltage smaller than |V1|.

Abstract: A method is disclosed for controlling the voltage applied to a voice coil motor coil during the retract operations of a mass storage device, comprising a combination of three different voltage regulator stages. This method includes providing a first circuitry stage adapted to source current to a voice coil motor apparatus, raising the voltage across the voice coil motor to a desired level, providing a second circuitry stage adapted to draw current from the voice coil motor effecting a desired voltage across the voice coil motor, and providing a third circuitry stage adapted to raise the voltage of the voice coil motor to ground by effectively shorting the voice coil motor to ground.

Abstract: An improved disk drive includes an improved operating system, an improved eject system, an improved head retract system and an improved motor loading system. In a preferred embodiment of the operating system it includes a motor, an eject crank, a head crank and an actuator. The output of the motor can be selectively controlled by the actuator to power either the eject crank or the head crank. Powering the head crank, causes the disk drive heads to move, and powering the eject crank causes a disk cartridge to be ejected from the disk drive. The motor loading system may have a disk drive motor having a threaded exterior and a member extending from the exterior to interface with the eject system. Additionally, this motor loading system may include an aperture in the chassis of the disk drive that has a threaded ring running around the circumference of the aperture and a spring extending from the threaded ring.

Abstract: The reaction force decoupling system, as implemented in a tape drive, reduces the motion that is coupled back into the tape cartridge from the reaction force that is generated by the operation of the read/write head actuator. The read/write head actuator consists of a magnet assembly which produces a large magnetic field in an annular gap and a coil of wire which operates freely in the magnetic field of the gap. The magnet assembly is mounted to the base of the drive and the coil is attached to the read/write head carriage. When current is applied to the coil, a force is produced between the coil and the magnet assembly to move the read/write head carriage. The magnet assembly is disconnected from the base of the drive and mounted on dual flexures arranged in a four bar linkage parallel guide arrangement. The reaction forces that are generated by the operation of the read/write head actuator must deflect the flexures to apply a load to the base of the drive.

Abstract: An improved micro-actuator position sensor which provides an accurate position signal for higher bandwidth control of a micro-actuator. The position sensor allows closed loop control of the micro-actuator position. Preferred embodiment micro-actuator sensors include a piezo-resistive stress sensor integrated within the springs, a capacitance sensor and magnetic reluctance sensor. Embodiments of the present invention are described in detail as integrated sensors for a micro-actuator used in hard disk drives. The sensor is integrated with a micro-actuator at the tip of the conventional actuator arm to improve the precision seeking capability of the actuator arm.