Abstract: An apparatus and associated method is provided for observing a positional misplacement of a control object at a first commanded position, defining a fault threshold as a function of the observed positional misplacement, and signaling a write unsafe command to the control object in relation to comparing an instantaneous positional misplacement of the control object to the defined fault threshold during self servo writing with the control object.

Abstract: Various embodiments of the present invention are generally directed to detecting a fixed mechanical reference adjacent a storage medium using a v-shaped pattern written to the medium.

Abstract: A shock absorbing device for protecting a hard disk drive housing found primarily in portable electronic devices. The shock absorbers include protuberances that emanate from the body of the shock absorber and that extend through apertures provided in the enclosure. Thus, the physical shock is taken up by the body of the shock absorber as well as the protuberances, which increase the compression height of the shock absorber and increase the shock damping characteristics of the shock absorber. This permits decreasing the size of the enclosure, which is often desirable to consumers.

Abstract: A read/write head for a disk drive having a shorting conductor from a shield of the read element to a conductor that runs from the write element to an external electrical contact pad. This allows for the measurement of the electrical isolation between the read sensor and the read shield via the external contact pads. Such a capability allows the electrical isolation to be measured both during the lapping process and subsequent to the heads being diced into separate sliders. This shorting conductor may be in the form of an internal shorting stud or in the form of an interim conductor that passes through the parting zone between adjacent heads. In the latter case, the shorting conductor is broken when the heads are diced so that a head of this embodiment can only be measured for electrical isolation prior to dicing.

Abstract: Disturbances to actuator control caused by external vibrations are corrected using feed-forward techniques that are selectively enabled or disabled based on signal values within a track follow loop. An increase in data integrity and reliability may be achieved by reducing off-track reads and writes caused by physical disturbances to disk drives during operation. Accelerometers detect external forces imparted on a disk and an acceleration feed-forward (AFF) signal is generated to compensate for disturbances to the location of a head caused by such external forces. Application of the AFF signal to an actuator may be based on whether signal values along the track follow loop exceed a certain threshold.

Abstract: Determining timing for bits in sampled data includes determining a bit error in the sampled data, determining a phase error in the sampled data, determining a frequency error of the sampled data based on the bit error and based on the phase error, and determining the timing for bits in the sampled data based on the determined frequency error.

Abstract: A disk drive includes a rotatable disk, a transducer, an actuator, and a controller. The disk includes a first servo burst pattern in a first radial spoke of the disk, and a second servo burst pattern in a second radial spoke of the disk. The first and second servo burst patterns are radially offset from each other and are associated with a plurality of data tracks extending through the first and second radial spokes. The transducer is configured to read the first and second servo burst patterns on the disk to generate a servo burst signal. The actuator is configured to position the transducer relative to the disk. The controller is configured to control positioning of the transducer relative to the tracks on the disk based on the servo burst signal.

Abstract: Automatically optimizing and programming features of a disk drive read channel for a selected partial response (PR) target. This enables flexible PR targets to be used in the read channel. The flexible PR targets can have arbitrary coefficients, and the channel features (parameters, functions and algorithms) that are dependent on the flexible PR targets are automatically adapted and programmed in hardware or firmware. With flexible PR targets, the read channel can support longitudinal and perpendicular recording without compromising performance.

Abstract: A disk drive stores overhead information corresponding to multiple servo sectors within a dedicated data sector in a customer data region of a data storage disk. The overhead information includes servo data for which the information content does not depend upon the physical location of the data on the disk surface. During a data storage operation, the overhead data is read from the dedicated data sector and stored in a buffer memory within the disk drive. A portion of the overhead data is then retrieved from the buffer memory for each servo sector subsequently traversed by the transducer for use in performing a data processing task related to the servo sector.

Abstract: A method for detecting signals affected by intersymbol interference provides for a path memory in the form of a trellis admitting survivor paths comprising a first and a second stage. The first stage includes a shift register exchange with a given number of states and a given length ?. The first stage outputs a first state SAkk-? on the survivor path for the best state Ak, and a second state SBkk-? on the survivor path for another state Bk. The second stage is configured as a two-state shift register exchange having a respective memory length ?, including respective first and second registers. In the respective first and second registers the survivor paths are stored leading to a respective first ?0k and second ?1k state, whereby the respective first register contains the backend of the best survivor path, while the respective second register contains the backend of an alternative survivor path.

Abstract: A method and apparatus are disclosed for restricting electrical connection to an electrical contact in a hard disk drive. A hard disk drive is provided which includes an electrical interface having a plurality of electrical contacts, and a restricting member. Access to at least one of the electrical contacts is restricted through the restricting member such that an electrical connection between the restricted contact and another electrical contact is avoided. The restricting member may be a shroud associated with the restricted electrical contact. The shroud includes an access passage which allows for an electrical connection between the restricted electrical contact and a contact on a self test rack. The shroud also prevents a shorting jumper from being placed on the restricted electrical contact, thus reducing the possibility of an inadvertent electrical connection between the restricted electrical contact and another electrical contact.

Abstract: A write pole for a read/write head of a disk drive system has a tapered surface on a leading edge thereof. Preferably, the tapered surface has a taper angle of between 0 and 20 degrees from a plane normal to the ABS. By having a write pole with a taper in this manner, sufficient write fields can be achieved even with thinner write pole tips on the ABS surface. By decreasing the thickness of the write pole tip in this manner while maintaining sufficiently high write fields, the skew profile of a write head can be decreased and areal density increased.

Abstract: Real-time correction of repeatable runout for multiple harmonic frequencies is provided by using convolution of a position error signal, or similar real-time signal, with an impulse response of a specific transfer function, such as the inverse of the disturbance transfer function. Multiple harmonic frequencies can be followed substantially simultaneously to achieve small position error and good tracking misregistration (TMR) performance. The impulse response can be obtained, calculated and stored off-line. The impulse response can be configured to substantially eliminate correction of one or more frequency or frequency ranges. Convolution can be done relatively quickly with proper arrangement of memory.

Abstract: A manufacturing apparatus and associated method for handling disks disposed in merged pairs in a carrier is provided, wherein spacings between adjacent pairs of the disks are greater than spacings between disks forming each pair. The apparatus includes a first disk contacting surface defining a first cavity that is sized to receivingly engage a selected one of the pairs of disks. A second disk contacting surface defines second and third cavities that are sized to receivingly engage individual disks of the selected pair of disks, wherein disks that are operably engaged in the cavities are spatially separated more adjacent the second disk contacting surface than at the first disk contacting surface.

Abstract: A clamping system includes a stack of storage media discs that includes an annular outer disc surface. A clamp includes a clamp surface that faces the outer disc surface. A ring is disposed between the clamp surface and the outer disc surface. The ring has a crested ring face with a circular crest line that contacts the clamp surface.

Abstract: In accordance with various embodiments, initial servo data are written to a storage medium as a series of radially overlapped spiral segments. Final servo data are thereafter written to the medium while concurrently servoing on said overlapped segments.

Abstract: A method for monitoring the operability of a slider of a disk drive includes the steps of providing a slider that includes a read/write head that magnetically interacts with a storage disk, and a slider mover that adjusts a head-to-disk spacing, controlling an electrical stimulus to the slider mover with a drive circuitry, measuring an actual electrical response from the slider mover with the drive circuitry, and comparing the actual electrical response to an expected electrical response to determine an operability status of the slider mover. Further, changes in the actual electrical response can be monitored and used to predict future failure of the slider mover.

Abstract: A method and apparatus for dealing with undesired deviations of servo burst component magnitudes, as compared with nominal magnitudes, is provided. Inaccurate servo burst magnitudes can arise from components which are misplaced, often from an inaccuracy in a trimming operation. In one aspect, a value indicative of the shift of a component null point is measured and used to calculate a burst amplitude correction factor. Knowledge of system dynamics can be used to calculate a track shape that can be used in calculating the correction factor. Values indicative of track shape can be related to transfer functions of the disk drive controller and plant. In one embodiment, information indicative of repeatable runout is convolved with a function of the transfer function of the controller and plant, and the result is used for calculating a burst component amplitude correction value.

Abstract: A method of providing a control output by selecting a controller to an actuator is discussed. A first controller having an estimator-compensator architecture is selected if the actuator is in a settle stage. A second controller having an architecture other than that of the first controller is selected when the actuator is in a track follow stage. The control output is provided from the selected controller to the actuator. The control output is indicative of the control signal.

Abstract: A disk drive flexure (115?) includes both a support layer (116) and an electrical insulator layer (122). A flex cable (101?) is disposed on the electrical insulator layer (122), and includes a plurality of slider bond pads (106?). The support layer (116) includes a bond pad support (119) for each slider bond pad (106?). Each bond pad support (119) is aligned with only a portion of its corresponding slider bond pad (106?), such that it supports less than an entirety of its corresponding slider bond pad (106?).