Abstract: An apparatus and method for detecting low flying read/write heads provides for the detection of contact between an air bearing slider/transducer assembly and a surface feature developed on a surface of a data storage disk. The apparatus includes a transducer disposed on an air bearing slider. An actuator is coupled to the slider/transducer assembly typically by employment of a head suspension assembly. The processor, in response to position error signals developed from servo information provided on the disk surface, moves the actuator and slider/transducer assembly to prescribed disk surface locations. The processor further processes non-repeatable position error signal values developed at a plurality of disk surface locations to detect an occurrence of contact between the slider/transducer assembly and a surface feature arising from the disk surface.

Abstract: A shock-resistant actuator assembly for use in a data storage system is disclosed. The actuator assembly includes an actuator body, fabricated from a first type of metal, having a central aperture for pivoting on an actuator shaft. The actuator body includes at least one composite actuator arm extending outwardly from the actuator body. The composite actuator arm includes a primary arm member, also fabricated from the first type of metal, and a plating of a second type of metal having a thickness of at least 20 microns disposed on an upper and lower surface of the primary arm member. In one embodiment, the primary arm member is fabricated from aluminum and subjected to an electroless nickel plating process to deposit a sufficient thickness of nickel thereon to appreciably increase the stiffness of the primary arm member. In another embodiment, an actuator comb assembly includes a plurality of integral composite actuator arms for supporting a plurality of head suspension assemblies.

Abstract: An apparatus and method for reading an information signal from a magnetic storage medium using a magnetoresistive (MR) head, and separating a thermal signal component and, if present, a magnetic signal component from the information signal. A signal separation/restoration module eliminates distortion in the magnetic signal component of a readback signal induced by a thermal signal component of the readback signal. A finite impulse response (FIR) filter may be employed in the signal separation/restoration module to eliminate the distortion in the magnetic signal. The signal separation/restoration module may be employed to extract the thermal signal component from the readback signal. In one configuration, an MR head is coupled to an arm electronics (AE) module, having a highpass filtering behavior, and a signal separation/restoration module that includes an inverse filter having a transfer function inverse to that of the effective highpass filter of the AE module.

Abstract: The present invention is a method and apparatus for positioning a magnetoresistive (MR) head relative to a storage medium in a storage device. The storage medium is mounted in the storage device to allow relative movement between the MR head and the storage medium. The storage medium includes servo information provided to induce a thermal response in the MR head. A controller controls the relative movement between the MR head and the storage medium using the thermal response induced in the MR head.

Abstract: The present invention generally provides a method and system for correcting for offset in a position error signal. In accordance with one embodiment of the invention, the readback signals dependent upon a read sensitivity profile of a read head are generated by moving the read head over a correction track. Using the readback signals, a characteristic value of the read sensitivity profile is determined. The characteristic value of the read sensitivity profile is used to adjust raw position error signals generated using the read head. The characteristic value may, for example, be determined from one or more data points from a cumulative sum data set. In accordance with another embodiment of the invention, a storage device is provided. The storage device includes a read head and a storage medium which includes a correction track and which is mounted to allow relative movement between the read head and the storage medium. The storage device further includes a servo control system.

Abstract: A head suspension assembly 10 wherein a tube 5, through which pass a plurality of covered wires 4, is clamped with a securing unit 6, a space between the covered wires 4 and the tube 5 is filled with a filler 7. The part of the tube 5 that is filled with filler 7 is clamped with securing unit 6. The securing unit 6 preferably is a claw section on the head suspension assembly. It is preferable that the tube 5is able to transmit light and the filler 7 can be cured by light.

Abstract: A disk substrate fabricated front an inner substrate having a specific stiffness greater than about 7.6 Mpsi/gm/cc and an encapsulating layer deposited over the inner substrate. The inner substrate may include materials such as alumina, silicon carbide, beryllium, boron carbide, aluminum, and mixtures thereof. The encapsulating layer may be made from aluminum, magnesium, copper, zinc, and mixtures thereof. The disk substrate may additionally comprise a finishing layer deposited on the encapsulating layer fabricate from a material such as nickel or an alloy thereof.

Abstract: A disk storage device in which two or more discrete disk velocities are used is disclosed. The disk velocity is selected using operating environmental conditions. Various types of sensors may be used to detect the environmental conditions or the environmental conditions may be input by a user. The allocation of track locations on a disk into zones reduces the number of zone bit frequencies the storage device must handle when multiple frequency zones are used in connection with the various spindle speeds.

Abstract: An apparatus and method for correcting asymmetry in the duty cycle of a differential signal is disclosed. The differential receiver circuit includes a first converter including a positive input coupled to a first direct current (DC) blocking capacitor, a negative input coupled to a second DC blocking capacitor, and an output resistively coupled to the positive input of the first converter. The differential receiver circuit further includes a second converter including a positive input coupled to the negative input of the first converter, a negative input coupled to the positive input of the first converter, and an output resistively coupled to the negative input of the first converter. The respective outputs of the first and second converters are preferably inverting outputs.

Abstract: An apparatus and method for delaying a signal using a variable delay line circuit. A variable delay line circuit includes first and second delay lines, each including a plurality of delay elements. A multiplexer is coupled to respective outputs of the first and second delay lines and selectively couples the output of one of the first or second delay lines to an output of the multiplexer. A control circuit is coupled to the multiplexer and the first and second delay lines, and controls the multiplexer so as to produce a delayed signal at the multiplexer output using one of the first or second delay lines, and changes a delay factor of the other one of the first or second delay lines by varying a resistance and a current of one or more delay elements of the other one of the first or second delay lines.

Abstract: A disk drive system has a servo pattern with bursts that are recorded without multiple passes per burst and without trimming, so that the servo pattern bursts have the same width as the data tracks. The servo write steps occur in partial data track pitch (DTP) increments. A magneto-resistive (M-R) head is used to both record the servo pattern and transduce it. In a two-frequency system, relative gain calibration is performed using AGC circuitry to first calibrate one frequency and then the other. The resulting servo position error sensing (PES) signal has improved linearity and is simpler to write.

Abstract: A data storage system is adapted for performing a plurality of data recovery procedures and data recovery routines. A selection switch is provided for manually selecting the plurality of data recovery procedures and routines preferably stored in, and performed by, a controller disposed in the data storage system. Alternatively, a host computer system, coupled to the data storage system, preferably produces a selection code instructing the data storage system to perform selected data recovery procedures and routines. Automatic execution of selected data recovery procedures and routines is facilitated by a controller in the data storage system which determines the type of data stored on the data disk, and executes selected data recovery procedures and routines upon detection of a read error in accordance with the determined type of the affected data.

Abstract: The present invention is a method and apparatus for positioning a dual element magnetoresistive (MR) head relative to a storage medium in a storage device. The MR head has first and second MR elements. The storage medium is mounted in the storage device to allow relative movement between the MR head and the storage medium. The storage medium includes servo information provided to induce first and second thermal responses in the MR elements. A controller is coupled to the MR head and controls the relative movement between the MR head and the storage medium using the first and second thermal responses in the MR elements.

Abstract: A global wire management apparatus and method for a multiple port random access memory (RAM) is disclosed. The RAM includes an array of stacked dual memory cell structures each including a common row/column decoder disposed between an upper memory cell and lower memory cell. The upper memory cell is situated adjacent upper transfer gate circuitry, and the lower memory cell is situated adjacent lower transfer gate circuitry. The decoder circuit is oriented vertically in the middle of the dual memory cell structure so that the true and complement decoder outputs may be fed upwards and downwards to the upper and lower transfer gate circuits. Wiring of the upper and lower transfer gate circuits may be effected completely at the local interconnect layer. Each of the write ports of the common decoder includes a NAND gate, an inverter, and a transfer gate for each of the upper and lower memory cells for controlling the transfer of data to the upper and lower memory cells.

Abstract: An improved apparatus and method for facilitating multiple write port access to a programmable memory apparatus is disclosed. A memory array, such as a random access memory array, includes a plurality of memory cells. A number of write ports are coupled to the memory array, each of which provides write access to individual memory cells of the memory array. Each of the write ports includes a NAND gate, an inverter, and a transfer gate. The NAND gate includes first and second inputs respectively coupled to a write row select line and a write column select line, and an output coupled to the input of the inverter and a first control input of the transfer gate. The output of the inverter is coupled to a second control input of the transfer gate. The input of the transfer gate is coupled to a data line, and the output of the transfer gate is coupled to a memory cell of the memory array.

Abstract: Raised irregularities in a magnetic data storage disk are removed by contacting an MR head with the relatively softer irregularity to abrasively erode the irregularity. The MR head may be brought into contact with the irregularity, for example, by selectively increasing read bias current of the head to expand the head toward the disk. Advantageously, removal of such imperfections helps eliminate thermal asperities created when the head inadvertently contacts raised irregularities during reading of data.

Abstract: A electronic apparatus and a process for its manufacture are disclosed. The apparatus includes a planar card for accommodating an electronics module package having protruding solder columns and solder joints to mechanically mount and electrically connect the solder columns of the module to the planar card. The planar card includes a first side and a second side, a plurality of wiring lines forming a wiring pattern, and a plurality of vias extending at least partially through the card. Each of the vias includes at least one recessed area extending from one or both sides of the card. The recessed areas extending to a depth within the planar card sufficient to wick the solder joints, and the each of the recessed areas are shaped to provide surface tension to mechanically retain the solder joints.

Abstract: A method and apparatus for calibrating a thermal response of an MR element spaced apart from a surface of a data storage disk is disclosed. A calibration feature, such as a depression, is provided on a surface of the disk. Signals are read from the calibration depression and a location on the disk surface other than the calibration depression using the MR element. Magnetic and thermal spacing signals are produced using the readback signals. A calibrated thermal spacing signal is produced using the magnetic spacing signals and the thermal spacing signals, such that the calibrated thermal spacing signal varies proportionally or, alternatively, linearly with respect to variations in spacing between the MR element and the disk surface. The calibration methodology is preferably performed in-situ a data storage system.

Abstract: A method for fabricating an air bearing slider for a data storage system including a deflection apparatus disposed on the air bearing surface of the slider. The air bearing surface of the slider is fabricated to include a transducer element mounting location biased toward a trailing edge of the slider, and a deflection apparatus disposed proximate the transducer element mounting location and biased toward a leading edge of the slider. Contact between the deflection apparatus and an asperity or disk obstruction prevents damage to a transducer element mounted at the transducer element mounting location. In accordance with one embodiment, the deflection protrusion is fabricated to include a sloping leading edge or, alternatively, comprises a plurality of deflection ridges that generally define a sloping leading edge.

Abstract: A multiple frequency zoned disk storage device in which data is read from and/or written to the disk at two or more discrete disk velocities is disclosed. The disk storage device includes a low power mode where information is read/written from/to the disk while the disk velocity is reduced to conserve power. The allocation track locations into zones on the drive reduces the number of zone bit frequencies the storage device must handle.