Abstract: The invention is generally directed to a disk drive head resetting system. The system has a slider with a disk drive head associated therewith. The disk drive head may be on the slider and affixed thereto. A heater is also associated with a slider and spaced apart from the disk drive head. A controller is communicatively coupled to the heater and to the head to transfer a first control signal to the heater and a second control signal to the disk drive head at substantially the same time. The first control signal may be used to generate heat past a blocking temperature of the head to substantially free a magnetic orientation of the head. While the first control signal is being transferred to the heater, a second control signal is transferred to the disk drive head to align a magnetic orientation of the head to a desired magnetic orientation.

Abstract: A disk-shaped magnetic recording medium having a reference track and a plurality of data tracks is rotated by a motor which generates an index signal at a predetermined position. A magnetic head is slightly moved in the radial direction of the medium for each predetermined unit distance smaller than the data track width, and a reproduction output amplitude measuring circuit measures the reproduction output amplitude of a signal read from the data track for each index signal. A CPU obtains a position where the amplitude has the maximum value based on the number of head movements and the amplitude at that time so as to control data track positioning. Further, the CPU calculates a relative position between the data track position and the reference track position to perform reference track positioning. The data or reference track positioning of the magnetic head can be performed accurately in a short time.

Abstract: A transducer is controlled during seeking based on an acceleration-phase state error. While seeking, the transducer is moved from an initial track to a target track on the disk based on a current command. At least one transducer state relative to the disk is estimated while seeking. At least one transducer state relative to the disk is measured while seeking. An acceleration-phase state error is determined that is indicative of an error between the estimated at least one transducer state and the measured at least one transducer state as the transducer is accelerated toward the target track during the seeking. The current command is generated based on the acceleration-phase state error.

Abstract: A storage device employing the ramp load/unload technique for an actuator is disclosed that has high shock-resistance, high vibration-resistance, and is capable of rapid and stable ramp load/unload operations. A position detection unit integrates the speed of the actuator, obtained by detecting a back electromotive force generated in a VCM, to calculate the present position of the magnetic head. A position determination unit compares the present position of the magnetic head with a series of position thresholds, and based on the comparison results, a bandwidth switching unit switches the bandwidth of a PI controller for feedback control of the actuator, from a narrow bandwidth to a wide bandwidth and vice versa. At positions where the speed starts to change or the speed change becomes small, the position determination is performed and the bandwidth is appropriately switched.

Abstract: Compensation for disk mode disturbances during self-writing of servo data is provided in a manner that accounts for differences in orientation between the disk surface from which position information is derived and the disk surface on which servo data is written. Microactuators corresponding to upper surfaces of disks may have a wiring polarity that is out of phase with the wiring polarity of microactuators corresponding to upper surfaces of disks so that disk mode compensation signals supplied to the microactuators produce motion in opposite directions. The servo control system may supply signals to microactuators individually and select the polarities of those signals to account for differences in orientation between the disk surface from which position information is derived and the disk surface on which servo data is written.

Abstract: A method and apparatus for efficiently calculating notch filter coefficients for a disc drive actuator arm control system is disclosed. In a preferred embodiment, filter coefficients for a z-domain notch-filter transfer function are calculated in fixed-point arithmetic from polynomial interpolations of the non-linear functions that define the coefficients in terms of the notch frequency. These non-linear functions may be derived and interpolated a priori by applying the bilinear transform to an s-domain notch transfer function. Since, in a preferred embodiment, the z-domain transfer function can be expressed as a fraction, the numerator and denominator of the transfer function can be scaled so as to allow the coefficients to be expressed as integers, thus making it possible to calculate the filter coefficients from the aforementioned polynomial interpolations using fixed-point math.

Abstract: A transducer is moved in a seek operation from an initial track to a target track on a disk based on a current command. The current command is regulated based on a location of the transducer and a location of an addressed data block on the disk. The current command may be regulated so that the transducer settles on the target track a predetermined time before the addressed data block reaches the transducer.

Abstract: Modern tape drives can adjust their tape drive velocity between two or more read/write data rates to better match the data rate demands of the host. This velocity changing may provide improvements in drive performance and total backhitch counts. The transition from one tape velocity to another may involve a rate change backhitch which itself could impact performance. It is desirable to optimize these transitions. In one approach, a backhitch involves a backvelocity having a magnitude that is intermediate between the initial tape velocity and the final tape velocity. In another approach, a backhitch involves an intermediate forward velocity to quicken the approach toward the start R/W reposition point.

Abstract: Embodiments of the present invention relate to systems, methods, and computer readable media for storing data on a rotatable storage medium. A hard drive having a rotatable storage medium is configured with different environmental tolerance characteristics for different sides of the rotatable storage medium. A first side is configured to have a higher tolerance to environmental factors such as shock and temperature by modifying features of the first side of the media and the read/write mechanism configured to interact with the first side. A second side of the storage medium is configured with lower environmental tolerances, thus allowing for higher performance. This configuration enables the hard drive to perform at a higher level of performance when facing less adverse environmental conditions while still remaining functional when facing more adverse environmental conditions.

Abstract: The present invention provides a tape drive apparatus enabled to directly and accurately detect dew condensation on a rotary head drum. Tape serving as a recording medium is drawn out of a cartridge. The drawn tape runs in such a way as to be wound on a tape takeup reel provided in a tape drive apparatus body. Signals are recorded on and reproduced from the tape by winding the drawn tape around the rotary head drum. This tape drive apparatus has a prethreading mechanism that brings the tape into slight contact with the rotary head drum before the tape is completely wound therearound. Dew condensation on the rotary head drum is detected by rotating the rotary head drum during a status in which the tape is brought by the prethreading mechanism into contact with the rotary head drum.

Abstract: Tape drive systems and methods for operating tape drive systems are provided. The system includes a head assembly having a head element for reading or writing data to a magnetic tape medium, and a pressure sensor coupled to the head element, the pressure sensor configured to generate a pressure signal representative of a pressure applied by the head element onto the pressure sensor. In some embodiments, an accelerometer is provided for sensing an acceleration of the head assembly and for generating a acceleration signal representative of an acceleration experienced by the head assembly. The method includes passing a tape medium between a take-up reel and a supply reel such that a tension in the tape medium causes the tape medium to apply a pressure onto a head element, and using a pressure sensor to detect a pressure applied by the head element onto the pressure sensor.

Abstract: An apparatus and method for removing mechanical resonance in a disc drive using an adaptive notch filter. Mechanical resonance harmful to a system is removed by a notch filter that adaptively varies the frequency characteristics of the filter with respect to the mechanical resonance frequency existing in the system.

Abstract: The present invention is relative to a recording and/or reproducing apparatus having a cassette tape exchanging function of selectively taking out a cassette tape (1) accommodated in a cassette holder (130) for recording or reproducing information signals. A cassette tape driving device (150) is arranged in an inner area of a toroidally-shaped rotational plate (121) passing through the proximity of a cassette insertion/ejection opening (112) formed in a front panel (111) of a cabinet (110). The cassette tape accommodated in the cassette holder is pushed towards the cassette tape driving device by grip arms (162A), (162B) of a cassette holding mechanism (160) mounted on the opposite side of the cassette insertion/ejection opening (112) or is pulled out so as to be accommodated in the cassette tape holder.

Abstract: A method for computing position error signal information of a transducer in a data storage system provides for different readback signals between adjacent tracks. The method involves a computation to obtain coarse position information from the servo bursts signals for track seeking and a computation to obtain a position indicator from the user data sector for more precise track following within the user data sector.

Abstract: The results of a calibration can be stored in a hard disk drive along with a hard disk condition indication. After the hard disk is re-started, it can be checked to see whether the stored hard disk condition indication is sufficiently close to a current hard disk condition indication. If the condition indication is sufficiently close, the stored calibration results can be used.

Abstract: A printed media self-servowriting process can be utilized whereby each wedge in the printed media pattern can have more than two servo bursts in order to effectively eliminate the high PES noise. A final pattern can be written based on the printed media pattern and eliminate the timing eccentricity suffered by the printed media pattern due to disk mis-centering. A radius can be determined such that more than two servo bursts can be can be used to determine the PES for radii between the radius and the OD, while only one or two servo bursts can be used between the radius and the ID. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.

Abstract: The results of a calibration can be stored in a hard disk drive along with a hard disk condition indication. After the hard disk is re-started, it can be checked to see whether the stored hard disk condition indication is sufficiently close to a current hard disk condition indication. If the condition indication is sufficiently close, the stored calibration results can be used.

Abstract: Tilt between a head stack and its associated disk stack in a hard disk drive (HDD) is measured by determining the deviation of a target head from its expected position (based on the position of the current head) each time electrical contact is switched from the current head to a target head. A running average tilt value is stored and used to modify the logical seek distance used in a Rotational Position Optimization (RPO) algorithm to better order I/O requests in a queue. Also, the running average tilt value can be used by the servo to pre-position the target head before electrical contact is made with the target head, to improve speed of operation.

Abstract: The invention operates two control paths. The micro-actuator control stimulates the micro-actuator. The voice coil motor control path includes the voice coil motor control generating a voice coil control signal, notch filtered to remove at least one significant excitation resonance for a notch filtered voice coil control signal. Amplifying the notch filtered voice coil control signal by a tuning gain stimulates the voice coil motor. A decoupling feedback filter uses the micro-actuator control signal to create a decoupling feedback signal used to decouple the two control paths. A track following command, with PES removed, directs the micro-actuator control. The voice coil motor control is directed by the track following command, with both PES and decoupling feedback signal removed. Preferably, the servo-controller digitally supports the elements of the invention. Implementing the method may preferably include the servo-controller program system residing in an accessibly coupled memory.

Abstract: In general, the invention relates to a data storage tape including servo information on both sides of the tape. Techniques for writing servo information to both sides of the data storage tape are also described. For example, a mechanical arrangement of two servo write heads positioned with respect to the data storage tape can enable two-sided servo recording. In addition, a single servo write head may be used to write servo information to both sides of the data storage tape with the aid of a flux conductor. In that case, the magnetic field of the servo write head passes through the data storage tape to record servo information on both sides of the tape.