Abstract: A head slider for use in a disc drive data storage system includes a slider body substrate having a cavity formed therein. A transducer is positioned in the head slider such that walls of the cavity in the slider body substrate protect the transducer from contact with asperities on a surface of a data storage disc.

Abstract: A writer portion of a recording head is disclosed. The writer portion includes a lower magnetic pole. An oxide gap is positioned on the lower magnetic pole. A first insulating layer is positioned on a first portion of the gap oxide, the first insulator layer having a planarized top surface. A plurality of intermediate insulating layers are positioned on top of the first insulating layer. Each intermediate insulating layer encapsulates a layer of conductive coils and has a planarized top surface. A last insulating layer is positioned on top of a portion of the plurality of intermediate insulating layers and on top of a second portion of the gap oxide. An upper magnetic pole is positioned on top of the last insulating layer and on top of a third portion of the gap oxide.

Abstract: A device for positively restraining data tape cassettes within a magazine of a cassette loading assembly to prevent the cassettes from becoming dislodged from the magazine when the cassettes are not engaged within the tape drive. The device includes a spring loaded cantilever having an end section which engages a detent conventionally formed in the edge portion of the data cassette tape. When the cantilever end section is engaged in the detent, the cassette tape is securely held against a rear interior wall of the magazine. The spring loaded cantilever is pivotally mounted by a shaft to an interior side wall of the magazine. In operation, a cassette transfer system engages the tape cassette to load the cassette into the tape drive. However, prior to such engagement, a bracket mounted on the cassette transfer system contacts a load-receiving end of the cantilever opposite the end section within the cassette tape detent.

Abstract: A hydrodynamic bearing is disclosed which includes a shaft and a rotor rotating relative to one another and defining a hydrodynamic bearing in the gap between the relatively rotating parts. Also disclosed is a method for identifying or signaling potential failure of the hydrodynamic bearing. The method for identifying or signaling potential failure includes a capacitance detector for generating a signal representing the capacitance across the gap defining the hydrodynamic bearing, a comparator for comparing the capacitance to an established threshold, and an indicator for providing a signal indicating that operation of the information storage device incorporating the hydrodynamic bearing should continue or that an interruption is likely.

Abstract: Data is detected from a disc in a disc drive and provided as a sampled read signal including data samples provided in a plurality of time intervals. A signal space detector is configured to detect the data, wherein the data is encoded according to a code having a time varying maximum transition run constraint which varies between a first and a second constraint over a plurality of time intervals. The detector is configured to receive an input sample including a first plurality of terms indicative of one of a plurality of possible data symbols. One of the plurality of possible data symbols is eliminated based on the first constraint when the input sample then being detected is constrained by the first constraint, to provide a second plurality of remaining possible data symbols. An estimated data value is determined which corresponds to the input sample then being detected, by determining which of the second plurality of remaining possible data symbols is within a predetermined range of the input symbol.

Abstract: A head-disk assembly contains an actuator that includes magnetoresistive heads and a preamplifier. The preamplifier is grounded to the actuator, and the actuator is grounded to a baseplate head-disk assembly via a ground conductor. A first inductive loop, which results in noise coupling on the pre-amplifier, exists based on the unequal potential between the actuator and the baseplate. The length of the ground conductor is minimized to reduce the area of the first inductive loop. A second inductive loop arises from a conductive path from the pre-amplifier leads to the baseplate via the actuator suspension, slider body assembly, magnetoresistive head, and magnetic disk media. A reduction of the unequal potential, which results in the second inductive loop, reduces noise coupling onto the inputs of the pre-amplifier. Conditioning of power, signal and control traces are also disclosed.

Abstract: Apparatus and method for detecting servo defects in a disc drive, the servo defects providing false indications of the position of a disc drive head with respect to a selected track. During use of a position error signal (PES) to position the head with respect to the selected track, the PES comprising a sequence of PES samples, the disc drive determines a first difference term as a selected combination of a first set of PES samples. A second, subsequent difference term is also generated as a selected combination of a second set of PES samples, the second set of PES samples including at least one PES sample which does not appear in the first set of PES samples. The magnitudes of the first and second difference terms are compared to a predetermined threshold, and a servo defect is detected at such time that both the first and second difference terms exceed the predetermined threshold and the first difference term exceeds the second difference term.

Abstract: A process for fabricating a magnetic data storage medium includes formation of a controlled texture, either over an annular transducing head contact area or the entire surface of a substrate. The texture layer is formed by vacuum deposition of a texturing material onto a smooth surface of a non-magnetic substrate. The texturing material has a surface energy greater than that of the substrate, and the texturing material and substrate material have different linear coefficients of thermal expansion. Just before deposition of the texture layer, the substrate is heated to a temperature of 200-600.degree. C., then allowed to cool during texture layer deposition. The substrate and texture layer contract at different rates as they cool, inducing mechanical stresses within the texture layer sufficient to plastically deform the texture layer, creating multiple dome-like bumps.

Abstract: An optical disc data storage system includes an optical disc for storing information in an optically readable format on a data surface. The slider is positioned proximate the data surface of the optical disc. An actuator coupled to the slider selectively positions the slider relative to the data surface. An optical waveguide having a radially graded index of refraction extends between a first end positioned proximate the light source and a second end coupled to the slider and positioned proximate the data surface. The optical fiber carries light therebetween.

Abstract: A flux sensitive device for creating electrical signals from magnetic flux produced by a magnetic piece has a first member defining a surface for sliding the magnetic piece. A conductive trace and a backiron are located proximate the first member such that the conductive trace is between the first member and the backiron. The position of the conductive loop is fixed relative to the backiron and the first member. The backiron forms a magnetic flux path with the magnetic piece and the conductive trace creates an electrical signal when magnetic flux crosses the conductive trace.

Abstract: A disc drive data storage system according to the present invention includes a housing, a central axis, a stationary member which is fixed with respect to the housing and coaxial with the central axis, and a rotatable member which is rotatable about the central axis with respect to the stationary member. A stator is fixed with respect to the housing. A rotor is supported by the rotatable member and is magnetically coupled to the stator. At least one data storage disc is attached to and is coaxial with the rotatable member. A hydro bearing interconnects the stationary member and the rotatable member and includes a blend of base fluids. The base fluids in the blend are selected such that one of the base fluids has a viscosity that is greater than a desired viscosity selected for the disc drive, another of the base fluids has a viscosity that is less than the desired viscosity and the blend of base fluids has a viscosity that is within a selected range of the desired viscosity.

Abstract: A method of forming a leading edge taper in a selected area on the bearing surface of a disc head slider includes directing an etching beam toward the bearing surface, with a first portion of the selected area being shaded from the etching beam and a second portion of the selected area being unshaded from the etching beam. The areas of the first and second portions are varied over time to form the taper.

Abstract: A disc drive spindle motor which has an increased resistance to operating and non-operating shock and vibration is provided, which improves the resistance to non-operating shock, is easy to manufacture and assemble, and which remains low in weight, low in height, and has low power consumption.

Abstract: A disc clamp assembly is provided for securing a plurality of information storage discs to a spindle hub on a disc drive spindle motor assembly. The disc clamp assembly includes a clamping ring and a resilient grip ring. The clamping ring has a raised Inner portion and rests on the information storage disc. The resilient grip ring has an inner diameter smaller than the diameter of the spindle hub, a middle portion to receive an axial force and a means for receiving radial force. The middle portion of the grip ring rests on the raised inner portion of the clamping ring. While the means for receiving radial force of the grip ring receives a radial force to radially expand the grip ring, the middle portion of the grip ring receives an axial force and applies the axial force to the clamping ring and the information storage discs. Upon removal of the radial force to the grip ring, the grip ring maintains the axial force applied to the information storage discs by gripping the spindle hub.

Abstract: A gimbal formed integral with a load beam by through etching a H pattern at the end of the beam to define a pair of tabs connected by a pair of beams; half etching from the head direction one tab with an defined area masked to form a load button; and half etching the beam from the other direction to provide the proper gimbal stiffness. In practice, the head is glued to the other tab and load is applied through the button.

Abstract: An amplifier especially suitable for use as a reading-head amplifier in a disc drive employing a magnetoresistive sensor. The amplifier is capable of injecting a fixed current into the magnetoresistive sensor and of providing an output signal dependent on the voltage developed across the magnetoresistive sensor as the resistance of the sensor varies in accordance with its magnetic environment.

Abstract: An air bearing slider for supporting a transducer proximate a rotating disc utilizes a raised air bearing surface that interacts with pressurized air to support the slider. The slider includes a slider body that has a leading edge and trailing edge relative to motion of the rotating disc. The air bearing surface has a leading edge portion proximate the leading edge of the slider body that is greater in width than a trailing edge portion positioned proximate and central with respect to the trailing edge of the slider body. The leading edge of the raised air bearing surface extends the entire width of the raised air bearing portion.

Abstract: An optical data storage system includes an optical disc which stores information in optically readable format on a data surface. A slider is provided proximate the data surface of the optical disc and is coupled to an actuator for selectively positioning the slider relative to the data surface. A Solid Immersion Lens couples to the slider and is arranged to couple light to the data surface of the optical disc. The Solid Immersion Lens is non-hemispherical.

Abstract: A data recording disk file includes rotatable disks with concentric data tracks thereon. The data disk file includes servo information recorded on at least one of the disks, at least one head for reading the servo information during rotation of the disk, and a voice coil motor (VCM) attached to the head for positioning the head relative to the data tracks. A servo is driven by signals read from the head to control the VCM. The servo includes a processor employing an estimator model for estimating the parameters of the VCM and for generating, from the estimated parameters and the servo information, a digital control signal. The digital control signal is converted to an analog control signal. The control signal is applied to a power amplifier which generates an input current for use by the VCM. The processor provides solely a single estimator model which operates in both saturated mode and linear mode depending on the magnitude of the digital PES.

Abstract: A vibration control device for controlling vibration of a disc drive supported in a compartment of a mass storage array. Disc drives stored in a compartment of a mass storage array may move within the compartment during operation of the mass storage array. Movement of a disc drive in a compartment may affect the performance of the disc drive to retrieve data from and write data to selected data tracks of a disc. In particular, vibration along an extent of the disc drive aligned with an operational stroke of the actuator mechanism may skew the operational stroke of the disc heads supported via the actuator mechanism. The vibration control device includes a spring which is adapted to exert a biasing force to a disc drive inserted into a compartment to restrict movement of the disc drive within the compartment.