Abstract: A method for assembling a mechanical system is disclosed. A magnet is installed into the system. An actuator having a magnetic element is also assembled into the system such that the actuator is movable between two extremes. At one of the extremes, the actuator is latched in place by way of the magnetic element, which forms a magnetic circuit with the magnet.

Abstract: Data integrity is increased on mass-storage devices through a scheme whereby, a frame-based cyclic redundancy code (CRC) for each sector is recorded. A frame-based CRC is generated from the CRCs of the frames that compose a sector of data. In recording data, a CRC is generated from each frame, later, a master CRC is generated from the frame CRCs, then sector and master CRC are recorded on the mass-storage device medium. In retrieving data, the sector composed of frames and a master CRC are read, a plurality of CRCs are generated from each of the frames, a second master CRC is generated from the frame CRCs, and the master CRCs are compared to determine data integrity. In another embodiment, an input/output error detection and correction checksum (IOEDC), an error correction code (ECC) and a CRC are generated from a sector of data, and the IOEDC, ECC and CRC are stored on disc with the data sector.

Abstract: An improved latch system for use in a disc drive is provided including an improved means for eliminating tolerances in the parked position of the actuator arm in the landing zone on the disc. According to this system, the latch system includes latch arm having a rotary engaging portion which engages a portion of the transducer support arm or actuator arm in the disc drive to prevent movement of the transducer when the shock appears; this latch arm is directly coupled to an air vane which extends parallel to the edge of the disc in a region nearly adjacent to the actuator arm and at a distance at a center of the disc which is just greater than the radius of the disc so that the vane extends partially along an arc or a line near to the edge of the disc. The latch arm and vane are arranged so that in the presence of disc rotation, wind generated by the disc presses against the vane, and the vane moves away from the disc.

Abstract: Information handling systems, disc drives, and methods for digitizing a readback waveform for testing a hard disc drive are disclosed. An information. handling system, such as a disc drive, includes a base, a disc stack rotatably attached to the base, and an actuator assembly movably attached to the base. Attached to one end of the actuator assembly is one or more transducers. Attached to the other end of the actuator is a voice coil that forms a portion of a voice coil motor. Magnets attached to the base form the other portion of the voice coil motor. An analog readback signal is reconstructed for use in testing a disc drive by digitizing a waveform generated within a read channel arrangement to produce digitized waveform data. The analog readback signal is then determined as a function of the digitized waveform data.

Abstract: An actuator and a method for using an actuator in a disc drive having a limited range of rotation wherein an actuator arm for providing motion for reading or writing data to or from media engages a shaft or post fixed within the actuator arm for communicating with the actuator arm by means of clips affixed to the shaft. The clips have flexible wings affixed to the actuator arm whereby the shaft and the actuator arm are held in a fixed relationship allowing the arm to rotate with respect to the shaft while movement between the actuator arm and the shaft other than by rotation is prevented by the shape of the flexible wings.

Abstract: A data storage communication channel includes a transmission medium, an initiator interface and a frequency selective multiplexer. The initiator interface includes first and second serial transmit ports. The frequency selective multiplexer includes first and second modulators and a circulator. The first and second modulators have first and second frequency bands and are coupled to the first and second serial transmit ports, respectively. The circulator is coupled between the first and second modulators and one end of the transmission medium.

Abstract: An improved system for mounting the head suspensions to the actuator mounting arms of a disc drive actuator. The mounting system of the invention includes novel features on both the head suspension mounting plates and on the actuator head mounting arms that facilitate head suspension mounting without the introduction of plastic deformation in any of the mounting elements. The mounting plate of the invention includes a boss and a hole. The boss and hole are dimensioned for interference fit with complementary elements on a second mounting plate located on the opposite side of the actuator head mounting arm, to provide the retention force of the mounting system. The bosses of the mounting plates also form an interference fit with cooperative holes in the actuator head mounting arm. Compliance features are included with the holes on the actuator head mounting arm to prevent plastic deformation of the material of the head mounting arm.

Abstract: A disk drive system is described for forming and reading precise optically detectable patterns on rotating members of a disk and spindle assembly used in data storage system. In particular the invention describes a magnetic disk drive employing a laser system to form and sense optical clock patterns placed on the rotating members of the disk drive. These optically detectable patterns are used to create an accurate clock track. The clock may be used to create multiple accurate magnetic patterns on one or more disks attached to a disk and spindle assembly in a magnetic data storage system. By successively changing the radius at which the magnetic patterns are created it is then possible to create multiple magnetic patterns at successive radii with all such magnetic patterns having a precise geometric relationship to each other. Alternatively, the accurate clock pattern may stand alone as an encoder.

Abstract: A disc drive, includes a base, a disc stack rotatably attached to the base, and an actuator assembly movably attached to the base. The actuator assembly includes arms on one end for holding the one or more transducers and a portion of a voice coil motor on the other end of the actuator assembly. A bearing cartridge is attached to an opening in the actuator assembly. A tolerance ring is used to attach the bearing cartridge to the opening in the actuator assembly. The tolerance ring includes a dampening material therein. The tolerance ring includes a layer of viscoelastic material which can be a viscoelastic damping adhesive material. The viscoelastic material is sandwiched between the first layer of metallic material and the second layer of metallic material. The tolerance ring includes a plurality of ridges formed about the periphery of the tolerance ring.

Abstract: A method of correcting track misregistration in a servo system for a disc drive including one or more discs includes positioning a head over a track located on a disc and maintaining the head centered over the track. The process for maintaining the head centered may include measuring the radial position of the head relative to the disc and determining correction factors for a zero acceleration path. Correction factors are determined by modeling an actuator transfer function to produce an estimated position signal. Subsequently, an estimated disturbance signal is determined by subtracting the measured position and the estimated position signal and filtering it with an adaptation filter. Thereafter, the estimated disturbance signal is subtracted from the measured radial position to produce a modified position measurement signal. The head is repositioned in accordance with the modified position measurement signal.

Abstract: A pivot mechanism is disclosed for mounting a rotatable actuator on a base of a disc drive. The pivot mechanism is made up of a shaft on which a housing is rotatably mounted by a lower ball bearing set and an upper bearing provided by co-acting surfaces of the shaft and the housing.

Abstract: One aspect of the invention relates to an apparatus and method for retaining a disc drive head disk assembly (HDA) during a servo track writing procedure. The HDA includes a base, a disc stack coupled to a spindle rotatably attached to the base by a spindle shaft, and an actuator assembly pivotally attached to the base at a pivot shaft. Attached to one end of the actuator assembly proximal the disc stack is one or more transducers for reading/writing information from/to the discs. In one embodiment, the method includes restraining the ends of the spindle shaft and pivot shaft during servo track writing so that relative deflection therebetween is minimized. That is, all but rotational motion of the components is substantially eliminated. An apparatus for restraining the ends of the spindle shaft and pivot shaft is also provided.

Abstract: There is provided an inertial latching system which includes a first latch member configured to engage a second latch member at a junction point. The first latch member includes a latch pivot mounted to the base. One side of the latch pivot extends to form a first arm whilst a balancing mass is found at another side of the latch pivot. Joined to the first arm is a finger which provides a contact line ending in a proximal point. The second latch member has a contact surface which provides a contact point. The inertial latching system is configured such that the ratio of a first length to a second length is smaller than the ratio of a third length to a fourth length.

Abstract: A disc drive includes a base and a disc rotatably attached to the base. The disc drive also includes an actuator assembly rotatably attached to said base and a device for moving the actuator assembly. The disc drive includes servo circuitry and a controller for controlling movement of the actuator and head switches during track seek operations. The disc drive determines the average seek time for each head and also measures the amount of time for a head switch from the transducer head having the shortest average seek time to all the other transducing heads in the disc drive. When a seek is performed, the controller in the disc drive determines if the shortest average seek time plus the seek time from the transducing head to the transducing head on the surface containing the target track and sector is less than the average seek time of the head on the surface having the target track and sector.

Abstract: A head and gimbal assembly (“HGA”) for supporting a pair of read/write heads at a desired fly height above a pair of adjacent discs. The HGA includes a rigid support arm, and a pair of thin, sheet metal suspensions mounted on opposed surfaces of the support arm. An end of each of the suspensions extends beyond an end of the support arm. These overhanging end portions include cutout sections defining a pair of back-to-back gimbals on which the read/write heads may be mounted. The suspensions may additionally include electrical connectors etched into the surface for transferring electrical signals between the read/write heads and the control electronics of the disc drive. In operation, a single HGA may be located between two adjacent discs, so that one of the heads on the HGA performs read/write operations on one of the two adjacent discs, and the other of the heads performs read/write operations on the other of the two adjacent discs.

Abstract: A slider assembly for selectively altering a position of a transducing head with respect to a track of a rotatable disc having a plurality of concentric tracks includes a slider body having a main portion and a head portion separated by a gap. The head portion carries the transducing head. The slider body is arranged to be supported by a support structure over a surface of the rotatable disc. A pair of structural elements are disposed on opposite side surfaces of the slider body between the main portion and the head portion across the gap. At least one of the structural elements is a microactuator responsive to electrical control signals to selectively bend to alter the position of the head portion with respect to the main portion of the slider body. The structural elements may be complementary microactuators.

Abstract: The present invention is used to form precise, optically detectable patterns on rotating members of a disk and spindle assembly of a disk drive used in data storage system. In particular, the invention employs an optical source to form optically detectable patterns on the rotating members of the disk drive. These optically detectable patterns are used to create an accurate clock track. The clock track may be used to create multiple accurate magnetic patterns on one or more disks attached to a disk and spindle assembly in a magnetic data storage system. By successively changing the radius at which the magnetic patterns are created it is then possible to create multiple magnetic patterns at successive radii with all such magnetic patterns having a precise geometric relationship to each other. Alternatively, the accurate clock pattern may stand alone as an encoder.

Abstract: A magnetic parking device for retaining an actuator in a disk drive over a landing zone. A magnetically permeable capture member is provided on the drive actuator and a magnetic parking member for capturing and magnetically retaining the capture member to park the transducer is provided adjacent the drive actuator. The magnetic parking member includes a permanent magnet and a magnetic field containing member having a slot (or air gap) formed therein. The magnetic field containing member and permanent magnet form a magnetic circuit with a magnetic flux with the slot in the magnetic field containing member allowing a portion of the magnetic flux to extend beyond the physical confines of the magnetic field containing member to provide a capture region for the capture member.

Abstract: The present invention provides for an improved printed circuit board assembly. The connector is straddle mounted to an edge of a printed circuit board with first connector leads configured for abutment with a primary surface of the printed circuit board (PCB) and second connector leads configured for abutment with a secondary surface of the PCB. Holes are provided in the PCB between the first connector leads. The second connector leads are arranged to abut the PCB directly where the holes open on the secondary surface. Solder is deposited on only the primary surface of the PCB directly on the locations where bond formation is desired between the first connector leads and the PCB, that is, on first contact pads. Solder is deposited in the same process on the primary surface, directly above the locations where bond formation is desired between the second connector leads and the PCB, that is, directly above the second contact pads on the other surface of the PCB.

Abstract: A disk drive having a novel actuator assembly. The actuator assembly comprises a voice coil motor assembly, a pivotable actuator arm, and a head gimbal assembly including a read/write head. The voice coil motor assembly is attached at a back end of the actuator arm, and the head gimbal assembly is mounted on the actuator arm on a front end opposite of the back end. The voice coil motor assembly includes a voice coil interposed between two magnets and a top plate and a bottom plate. The voice coil motor assembly is secured to the base of the disk drive by posts. The actuator arm includes the back end, a pivot point and impeding apertures. The impeding apertures include two holes located near the back end of the actuator arm between the pivot point and the voice coil motor assembly and extend entirely through the actuator arm. The actuator arm may also include plugging members. The plugging members are inserted into the impeding apertures and extend entirely through the impeding apertures.