Abstract: A method and apparatus are provided for improved position error signal (PES) demodulation in the presence of thermal baseline wander. A plurality of samples is obtained within each period of a burst signal for each servo burst in a servo sequence. A difference value is identified between a largest sample value and a smallest sample value of the plurality of samples within each period of the burst signal. The difference values for each period of the burst signal for each servo burst in the servo sequence are summed to produce a burst sum value for each servo burst. Then the burst sum values are used to identify a position error signal (PES) value. The identified PES value is independent of any transient baseline voltage offset disturbances, for example, resulting from the occurrence of baseline wander offset, such as caused by a thermal asperity (TA), in the servo sectors.

Abstract: A method and apparatus are provided for implementing a compact portable computer system. The compact portable computer system includes a keyboard and a computer display disposed above and generally parallel to the keyboard. A pivot mechanism and a pair of supporting arms are coupled between the pivot mechanism and a respective one of the keyboard and computer display for adjustably positioning the computer display above the keyboard.

Abstract: A position error signal indicative of the distance between an expected position of a magnetic head relative to the track centerline of a magnetic data storage and retrieval system and an actual position of the magnetic head relative to the track centerline is detected. An absolute value of the position error signal is determined and stored. The detection, determination, and storage is repeated over several revolutions of the magnetic data storage and retrieval system. A maximum of the absolute values of the position error signals is then determined and compared to a threshold value. If the maximum of the absolute values of the position error signals exceeds the threshold value, a warning signal is propagated. An alternative embodiment similarly predicts the possibility of head-disk crash on the basis of the maximum value of several samples of the squares of the position error signals.

Abstract: A computer hard disk drive has a drive controller that monitors the condition of the head-disk interface within the drive. In response to sensing a degradation of the head-disk interface, the drive prolongs the onset of failure by selectively altering performance parameters. In one embodiment, the internal pressure of the drive is increased to allow the air bearing surfaces of the heads to achieve a greater flying height above the surfaces of their respective disks, thereby delaying the onset of a catastrophic head-disk interface failure. In other embodiments, the spindle rotation rate and/or the slider head access rate are decreased to avoid hastening the imminent failure. Measurements of the condition and stability of the head-disk interface inside the drives are made by monitoring data error rates, head flying height, or other performance variables.

Abstract: A method and apparatus are provided for identifying spindle imbalance in a hard disk drive. Position error signal (PES) samples are received from a plurality of sectors of a predefined cylinder for a plurality of disk surfaces. The PES samples are measured and stored for a defined number of revolutions for each of the plurality of disk surfaces. For each of the plurality of disk surfaces, a repeatable runout (RRO) of the PES is computed for the defined number of revolutions. A first harmonic discrete Fourier transform (DFT) and a first harmonic phase of the RRO are computed. Then a mean repeatable runout (MRRO) is computed. A first harmonic DFT and a first harmonic overall phase of the MRRO are computed. For each of the plurality of disk surfaces, cross-correlation coefficients are computed and summed to identify a spindle imbalance factor. The identified spindle imbalance factor is compared with a predefined threshold value to identify spindle imbalance in the hard disk drive.

Abstract: A method for highlighting a desired portion in an audio sequence for use in a visual display challenged environment. The method includes storing the audio sequence in memory. Next, the user selects a desired portion of the audio sequence and the selected portion is distinguished from the remainder of the audio sequence by automatically varying an audio characteristic of the selected portion during playback, without permanently altering the selected portion. In a related embodiment, the audio characteristic that is varied is pitch of the selected portion.

Abstract: To optimize the life of a magnetic disk data storage device it is recognized that the accessing of data on the disk data surface should mimic the varying effective lubricant protection over the disk surface. The lubricant applied to the disk data surfaces migrates outward during drive operation. To match the disk surface protection to the frequency of data accesses at the storage locations, the stored data files are periodically examined to determine how recently access has occurred and the number of accesses during a most recent fixed period to determine whether the data file is to be stored in radially inner or radially outer portions of the band of concentric data tracks. By thus allocating the data file storage location, the data is accessed and intermittent contact between disk surface and transducer carrying slider occurs with greatest frequency where the lubricant coating is least depleted and most robust.

Abstract: A method and apparatus for estimating the value of a slider airbearing resonance frequency involves obtaining a readback signal from a data storage medium over a plurality of complete airbearing periods and estimating the value of an airbearing resonance frequency using the readback signal. In one embodiment, a discrete signal segment comprising a plurality of frequency transform components is produced using the readback signal information, and the value of the airbearing resonance frequency is estimated using spectral leakage in the discrete signal segment. A ratio of the magnitudes of a first DFT component to a second DFT component is computed at each of a plurality of sampling rates. Each of these sampling rates is defined by a number of samples per average airbearing cycle multiplied by a frequency falling within a range of expected airbearing frequencies associated with a given implementation.

Abstract: Embodiments of systems, methods and article of manufacture provide for readback signal detection and analysis. One embodiment provides an in-situ system to detect envelope traces of a readback signal. Using the envelope data, the presence of undesirable activity and/or storage medium surface conditions may be determined. For example, head modulation may be determined. Upon detection of a modulation event in a sector or a track, the compromised data may be recovered using a signal processing system. Another embodiment provides for detection of a thermal signal component in a readback signal. The thermal signal is processed for surface information indicative of the surface condition. Information indicating a defect may then be used to avoid storage areas having the defects.

Abstract: A hard disk drive actuator includes a plurality of arms for holding the heads over the disks. Each arm has one or more contaminant collectors for collecting contaminants, such as airborne particles, humidity, and/or organic gasses during operation. The contaminant collectors can take a variety of forms, including air porous filters mounted within existing cutouts within the plurality of arms. In this instance, the plurality of arms may be aerodynamically shaped to create a pressure differential between the top and bottom surfaces of the arms, causing an increased airflow through the filters. In another instance, the contaminant collector is a material applied to the top and bottom surfaces of the plurality of arms which attracts and/or captures airborne particles during normal operation.

Abstract: Embodiments of systems, methods and article of manufacture provide for readback signal detection and analysis. One embodiment provides an in-situ system to detect envelope traces of a readback signal. Using the envelope data, the presence of undesirable activity and/or storage medium surface conditions may be determined. For example, head modulation may be determined. Upon detection of a modulation event in a sector or a track, the compromised data may be recovered using a signal processing system. Another embodiment provides for detection of a thermal signal component in a readback signal. The thermal signal is processed for surface information indicative of the surface condition. Information indicating a defect may then be used to avoid storage areas having the defects.

Abstract: An apparatus and method reduce the transfer of vibration to and/or from a data a data transfer mechanism in a data storage device by coupling an adaptive mount responsive to an electrical stimulus to the data transfer mechanism. In one embodiment of the invention, a controller reads a signal that relates to the position error of a read/write component in a data transfer mechanism, applies an algorithm, and varies the damping of an adaptive mount coupled to the data transfer mechanism. The controller may be further configured to report an error to a host system that identifies a substandard data transfer mechanism so that such data transfer mechanism can be repaired or replaced.

Abstract: A method and apparatus for detecting lubricant depletion in a disk drive is provided. Disk operation performance parameters are monitored for each of a plurality of zones on the surface of the disk, and the performance parameters are stored in a data store. Examples of performance parameters monitored for each of the zones include dwell time, head flying height changes, and data recovery procedure measurements. The stored disk operation performance parameters are then compared against predetermined threshold values. If the values of the performance parameters exceed the predetermined threshold values for any of the zones, a potential lubricant depletion or other general degradation problem is flagged for the corresponding zone. Optionally, when a potential lubricant depletion problem is flagged for a particular zone, corrective action is taken.

Abstract: A method and apparatus for positioning a transducer relative to a storage medium in a storage device. The storage medium is moved relative to the transducer by a motor at a rated storage medium velocity. The storage medium has a plurality of tracks, each having a first edge and a second edge. The first edge and the second edge respectively comprise surface profile variations having a temporal frequency at the rated storage medium velocity. The surface profile variations of the first and second edges are phase modulated, i.e., have a phase difference relative to one another. First and second responses, e.g., thermal responses, are respectively induced in the transducer by the phase modulated surface profile variations of the first and second edges. The transducer may be positioned by a controller, for example, based on at least one of the first and second thermal responses. A storage medium having phase modulated surface profile variations is relatively easy to fabricate.

Abstract: A magnetic disk drive is provided with clamping rings that whenever nested will form an annular chamber to accommodate a toroidal ring which is deformable. As the clamping rings are progressively forcefully engaged by the clamping rings, the chamber is reduced in height and transmits the force of the top clamping ring to the bottom clamping ring in a uniform distribution and prevents the force of the bottom clamping ring from having non-uniformity of distribution. This action prevents magnetically recordable disks of the disk drive from being subjected to point loading and consequential warping. The uniform distribution exerted on glass disks also prevents cracking or shattering of the glass disk and prevents warping of non-glass disks.

Abstract: A method and apparatus for improving the reliability of hot spare disk drives in disk arrays and storage networks is provided. The invention analyzes commands issued to active disk drives in a disk array/storage network, and issues commands to the hot spare drives which attempt to emulate the track usage patterns of the active drives. The track usage patterns can be inferred from examining logical block addresses (LBA) of data stored to the active drives, and/or the ratio of read versus write commands issued to the disk drives. By emulating track usage patterns of the active drives, the spare drives have a roughly equivalent lubricant distribution to that of the active disk drives. This provides increased reliability when the hot spare drives are called into active service.

Abstract: A shrouded hard disk drive includes one or more contamination filter cavities embedded within the shroud for capturing airborne contaminants circulated within the drive during normal operation. The present invention takes advantage of naturally occurring radial and circumferential velocity differences between air at the edges of the disk pack and the air at the filter cavity entrance opening (i.e., the inner circumference of the shroud) to redirect airflow through a filter positioned within the one or more filter cavities. After air passes through the filter, it exits through a filter cavity exit opening positioned in proximity to either in the area between the disks, or the area above or below the disk pack.

Abstract: A magnetoresistive (MR) head of a hard disk drive provides a readback signal from a data storage disk. The readback signal is high pass filtered, amplified, sampled and digitized to obtain a digital readback signal. A thermal component of the digital readback signal is removed from the digital readback signal by an efficient nonlinear process in which an envelope of the digital readback signal is estimated to obtain upper and lower envelope sequences. The upper and lower envelope sequences are averaged to derive the estimated thermal component to be subtracted from the digital readback signal.

Abstract: A slider having leading and trailing edges is configured to fly on an airbearing above a data storage disk rotating from the leading edge to the trailing edge. Read and write heads are mounted on the slider proximate the trailing edge. An auxiliary thermal sensor is mounted on the slider, but preferably nearer the leading edge. Forward placement of the sensor allows it to sense mechanical defects before they reach the heads, thereby permitting a write inhibit operation, for example. The sensor may also be used to detect airbearing modulation. Appropriate action may be taken when unacceptable airbearing modulation is detected, such as notifying the user and/or scrubbing the slider. The sensor is preferably wider than the heads. This allows, for example, an in-situ glide test to be performed faster using the sensor. An arm electronics module is preferably configured to permit concurrent operation of the sensor and heads.

Abstract: A slider having leading and trailing edges is configured to fly on an airbearing adjacent a data storage disk rotating from the leading edge to the trailing edge. Read and write heads are mounted on the slider proximate the trailing edge. An auxiliary thermal sensor is mounted on the slider, but preferably nearer the leading edge. Forward placement of the sensor allows it to sense mechanical defects before they reach the heads, thereby permitting a write inhibit operation, for example. The sensor may also be used to detect airbearing modulation. Appropriate action may be taken when unacceptable airbearing modulation is detected, such as notifying the user and/or scrubbing the slider. The sensor is preferably wider than the heads. This allows, for example, an in-situ glide test to be performed faster using the sensor. An arm electronics module is preferably configured to permit concurrent operation of the sensor and heads.