Abstract: A node-and-strut structure is made so as to include a “hyperstrut spine” of at least 6 to 10 similar “vertebrae.” Each such vertebra includes one “left-hand strut,” one “right-hand strut,” and one “primary” node rigidly engaging a proximal portion of the left hand strut and of the right hand strut. These vertebrae are arranged so that the primary nodes each intersect a primary axis, so that the left-hand struts are all (nominally) parallel with one another, and so that the right-hand struts are similarly all parallel with one another.

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: A system for loading a transducing head (22) to a flying elevation proximate a rotating surface of a disc (16) is disclosed. The system includes a piezoelectric device (40) that is selectively expanded and contracted to control a height of the head (22) on a flexure spring (14) from the surface of the disc (16). The system preferably includes control circuitry (50) for generating electrical control signals to manage the expansion and contraction of the piezoelectric device (40) according to operating characteristics of the disc (16).

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 system and method is disclosed for correcting gain and offset errors in a signal amplifier for a position sensitive detector. The present invention eliminates the need to perform division for normalization by holding constant a signal proportional to the sum of the two signals generated by the position sensitive detector. First the two signals generated by the position sensitive detector are pulse-width modulated with a common variable duty cycle clock, and then the resulting modulated signals are low-pass filtered to extract the DC component. The duty cycle is varied so that the sum of the two DC components is held constant. In the preferred embodiment, the means for varying the duty cycle are closed-loop feedback and open-loop feed forward. The closed-loop feedback gives long term accuracy and the open-loop feed forward gives rapid settling time.

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.

Abstract: A read/write preamplifier circuit is provided that includes a fault detecting circuit that detects when two or more read/write preamplifiers are concurrently selected for communicating with their associated data heads and means for notifying the drive controller of that condition. In one embodiment of the invention, the means for notifying the drive controller that two or more preamplifiers are concurrently selected includes a data storage register that is readable by the drive controller and that has a fault flag which is set when two or more preamplifiers are concurrently selected. Also, in one embodiment, the fault detecting circuit includes a fault-detect transistor that drives a predetermined current if the preamplifier is elected. The collectors of the fault-detect transistors of each preamplifier are electronically coupled to each other and to a sensing circuit that senses if the fault-detect transistors of two or more preamplifiers are concurrently driving the predetermined current.

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: A spacing between a transducer head and disk surface in a disk drive's head-disk interface is monitored. The transducer head includes a magneto resistive element. The surface of the disk includes a region containing at least one asperity extending from the surface to have a height. The transducer head is placed over the region containing the at least one asperity, and the disk is rotated. A determination is then made as to whether the transducer head contacts the at least one asperity.

Abstract: A method and apparatus for releasing an actuator from a latched position. A voice coil motor is operably coupled to the actuator which is held by a latch in a latched position. The voice coil motor is provided with a first current signal of increasing magnitude alternating with a second current signal out of phase with the first current signal. The first current signal causes the voice coil motor to urge the actuator away from the latched position, and the second current signal causes the voice coil motor to urge the actuator towards the latched position.

Abstract: A disk drive manufacturing system and process which includes head to disk interference equipment, servo writing equipment, formatting and controlling firmware. The system servo writes a varying number of data tracks per disk surface while sensing when the head is positioned over the transition and/or landing zones of the magnetic disk surface. The servo writing of tracks continues as far as possible on each disk surface, and stops just before the transition zone region of the landing-zone is encountered. Each disk processed has a varying number of data-tracks per surface, which variable data-track information is factored and utilized in a further step of formatting the disk in accordance with the changed boundaries of the data zone and in accordance with instructions received from a disk drive's formatting and controlling firmware.

Abstract: A method of determining the subtrack within zone P on a recording medium is provided. The recording medium has a plurality of zones 1 through Q. Each zone has a plurality of subtracks 0 through M. Each subtrack has a plurality of sectors 0 through N. Each sector has a position identifier field. Each position identifier field has a plurality of information units for recording a position identifier. The position identifier for Jth sector of subtrack I is identified as S(I,J). A preferred method comprises obtaining the local subtrack value as S(I,0), a space-efficient way to store and extract subtrack location information.

Abstract: Servo-pattern information is magnetically recorded on a product disc by magnetic print-through from a master medium. The master servo-writing medium is brought into close proximity with the product “slave” disc, and the two are subjected to an external magnetic field which assists in transferring magnetic servo-patterns to the slave disc in a print-through process. The preferred external magnetic field alternates and rotates with respect to the master/slave combination. In an alternative product disc structure, the magnetic layer is magnetically altered in a servo-pattern configuration. Non-magnetic portions of the servo pattern are created which define both gray code and servo burst information for the product disc.

Abstract: An improved locking system for securing the actuator of a disc drive at a park position. The locking system includes a rotatable lock mechanism that is normally biased to a lock position. When the actuator is moved to the park position, a cooperative lock feature on the moving portion of the actuator interacts with a pawl feature on the rotatable lock mechanism to momentarily overcome the biasing force. When the lock feature on the moving portion of the actuator moves beyond the pawl feature, the bias force acts to return the rotatable lock mechanism to its locked position with the pawl feature engaging a cooperative surface on the lock feature to lock the actuator at the park position against a lightly compressed compliant limit stop and to maintain the actuator at the park position in the presence of applied mechanical shocks.

Abstract: In a peak detection system having a variable gain amplifier (VGA), a counter is initialized and a countdown is triggered. Each time a qualified peak is detected, the counter is re-initialized. If the countdown is completed, the VGA gain is updated. This method can be used to boost amplifier gain that is too low to generate a qualifying threshold, even while overlooking short periods of very low output.

Abstract: A narrow read head and a wider write head are used to store and retrieve data from a storage medium, such as a magnetic disk or tape. The wider write head is selectively positioned to record overlapping data tracks. The read head is subsequently positioned to read the non-overlapping portions of the data tracks. In one format, a read seldom data block is recorded by sequentially recording a plurality of data tracks such that each subsequent data track partially overlaps a previously written data track. In another format, pairs of data tracks are recorded by side-by-side, wherein within each pair of data tracks there is an overlapping region. In either format, the narrower read head is positioned to read the non-overlapping portions of the data tracks. Consequently, the storage capacity of the storage medium is optimized to take advantage of the narrow read head.

Abstract: Servo-pattern information is magnetically recorded on a product disc by magnetic print-through from a master medium. The master servo-writing medium is brought into close proximity with the product “slave” disc, and the two are subjected to an external magnetic field which assists in transferring magnetic servo-patterns to the slave disc in a print-through process. The preferred external magnetic field alternates and rotates with respect to the master/slave combination. In an alternative product disc structure, the magnetic layer is magnetically altered in a servo-pattern configuration. Non-magnetic portions of the servo pattern are created which define both gray code and servo burst information for the product disc.