Abstract: A disk drive for storing data includes a drive housing, a storage disk that is rotatably coupled to the drive housing, a slider assembly positioned near the storage disk, and a drive circuitry. The slider assembly includes a head that interacts with the storage disk during a data transfer operation and a slider mover. The drive circuitry directs a first power level to slider mover to maintain the head at a first HtD spacing, and a second power level to the slider mover to maintain the head at a second HtD spacing, and a variable, transition power to the slider mover during a transition between the first power level being directed to the slider mover and the second power level being directed to the slider mover. The transition power is tailored to rapidly move the head between the HtD spacings.

Abstract: A disk drive is disclosed for connecting to a host, the host comprising loopback circuitry operable to loop a pattern received from the disk drive back to the disk drive. The disk drive comprises interface circuitry including a transmitter driver operable to transmit transmission signals at a transmission amplitude, and a receiver driver operable to receive reception signals. The transmitter driver is configured to transmit at an initial transmission amplitude, and a calibration pattern is transmitted to the host through the transmitter driver. The reception signals received by the receiver driver are monitored to detect a loopback pattern representing a loopback of the calibration pattern. The loopback pattern is processed to detect an error, and the transmission amplitude is adjusted in response to the error.

Abstract: A storage device, which comprises a storage media, a spindle motor which spins the storage media, a head unit which records and reads the data to the storage media, an actuator which carries out the positioning operation to the head unit on the storage media, a loading and unloading system which controls the actuator and carries out the unload operation that withdraws the head unit from the storage media and the loading operation that shifts the head unit onto the storage media, and a measurement means which measures the unloading energy required for the unload operation.

Abstract: Embodiments of the invention eliminate noise from burst signals by use of a reliable and simple method. In one embodiment, the read processor of the HDD has a noise elimination circuit. The noise elimination circuit retains multiple integral values of the waveform absolute values for each period in the burst signals read out from the head, then removes a maximum value and/or a minimum value from the multiple integral values, and transmits the remainder as noise-eliminated signal data. The noise elimination circuit is a circuit for eliminating noise from an N number of periods of burst signal data, and this circuit integrates the absolute values of the waveforms for each period in the N number of periods of burst signal data, compares the integral values of each period with one another, and outputs the remainder obtained by removing the maximum and minimum integral values, to the servo data decoder of the following stage.

Abstract: A method and apparatus for controlling a track seek servo of a disk drive. The method of controlling the track seek servo of the disk drive having a transducer and a disk with a plurality of tracks, includes moving a transducer to a space over a target track of the plurality of tracks according to a track seek controlling process in which an asymmetrical sine wave acceleration trajectory a(t) is used in a track seek mode.

Abstract: Disclosed is a self-heating disk drive that comprises a voice coil motor (VCM), a spindle motor, and a temperature sensor. The VCM includes a VCM coil and the VCM is configured to move an actuator having a head attached to a distal end of the actuator. The spindle motor includes a plurality of spindle coils to spin a disk of the disk drive. The temperature sensor is used to read an internal temperature of the disk drive. Circuitry is configured to: command the application of current to the VCM coil without loading the head onto the disk and to the spindle coils of the spindle motor in a manner so as not to spin the disk; and, if the internal temperature reading reaches a pre-determined spindle temperature, the spindle motor is allowed to spin-up the disk.

Abstract: A method for writing servo information onto a disk of a hard disk drive. The method includes writing a reference servo pattern onto a track of a disk with an off-line servo track writer. The reference servo pattern has less servo bits than the final pattern allowing the off-line writer to write in a single pass. The disk is then assembled into a hard disk drive assembly and a final servo pattern is written onto the track. The final pattern can also be written with two passes. The single pass writing process reduces the time required to write the servo information. Additionally, the off-line servo track writer can write servo on a plurality of disk at the same time, further reducing the process time for writing servo and mass producing hard disk drives.

Abstract: A method of managing power used by a recording medium is disclosed. The recording medium receives a maximum current value and limits its operation to consume up to the maximum current value during a given storage operation. The recording medium may comprise a storage module coupled to a controller. The controller in the recording medium may receive the maximum current value and limit the operation of the recording medium to the maximum current value.

Abstract: A magnetic recording disk drive with rotational vibration (RV) cancellation uses the position error signal (PES) and the signal from a RV sensor to determine when to enable and disable RV cancellation. An RV feedforward compensation signal to be summed with the VCM control signal is “switchable”, meaning that it can be enabled or disabled by the disk drive servo control processor. The determination to enable or disable is made from a comparison of the PES with a threshold PES, which may be an estimate of the off-track position of the head calculated from the RV sensor signal. The estimated off-track is compared to the absolute value of the actual or measured PES. If the estimated off-track is smaller than the actual PES, then the state of the RV cancellation is switched, i.e., if it is enabled it is disabled and if it is disabled it is enabled.

Abstract: In one embodiment, a magnetic disk apparatus comprises a magnetic disk for recording information; a magnetic head that reads information from, or writes information to, the magnetic disk; an actuator device that drives the magnetic head; and a control system that controls the driving of the actuator device. The actuator device is configured by a dual stage actuator comprising a fine actuator that drives the head and a coarse actuator that drives the magnetic head together with the fine actuator. The control system includes a fine controller that generates an operational value for driving the fine actuator and a coarse controller that generates an operational amount for driving the coarse actuator. The control system includes a mechanism for smoothly changing the operational amount generated by the fine controller immediately before saturation resulting from an applied voltage limit of the fine actuator or at the time the fine actuator returns to a control range from the saturation.

Abstract: Disk drives in a storage system are spun up in sequential stages. During each sequential stage a number of disk drives is spun up based on parameters related to the power requirements of the system. The parameters include the maximum current for the storage system, the number of disk drives currently in steady state, the steady state current required for a disk drive, and the spin up current required for a disk drive. High availability features are provided as further aspects of the spin up mechanism.

Abstract: In one embodiment, a magnetic write/read device comprising a magnetic read element and a magnetic write element is formed in a thin film magnetic head portion of a magnetic head slider. A heat generating resistor is formed between a substrate portion and the magnetic reproducing device for heating thereby thermally expanding and protruding a portion of the magnetic head slider to control the flying height. The heat generating resistor is positioned between the substrate portion and the magnetic reproducing device being apart from the magnetic reproducing device for making the response speed for the flying height control of the magnetic head slider as high as possible and decreasing the effect caused by the heat generation of the heat generating resistor on the magnetic reproducing device as little as possible.

Abstract: First, data is read from tracks formed on a tape-shaped recording medium by heads disposed on a rotary drum, to measure error rates. Next, of the tracks formed on the tape-shaped recording medium, a worst track suffering the highest error rate is detected based on the error rates thus measured. Then, a pair of reproducing heads that can reproduce the worst track thus detected at the lowest error rates is detected from the measured error rates. Thereafter, tracking servo control is performed such that the worst track can be scanned by the pair of reproducing heads. As a result, a reproducing apparatus capable of proper reproduction even when recorded tracks undergo variations in width and reproducing heads are erroneously mounted.

Abstract: A hard disk drive that redefines a notch filter of the drive. The update process may include initially disabling all notch filters and inducing a seek operation of the disk drive heads. A position error signal is read during a settling time of the seek operation and processed to determine the frequency of the signal. The frequency is selected as a resonant frequency if the error signal magnitude exceeds a threshold value. The notch filter is then redefined in accordance with the selected resonant frequency. The controller may also perform a routine to determine whether the resonant frequency is above or below a Nyquist frequency. Unlike prior art techniques, the method disclosed can obtain the resonant frequency without sweeping the excitation signal of the disk drive voice coil motor.

Abstract: A method for writing servo information onto a disk of a hard disk drive with a servo writer. The method includes writing a plurality of spiral servo signals with a head. The spiral servo signals are used to write servo patterns using at least one timing window. The timing window is adjusted using a position error signal generated from the spiral servo signals. The adjusted timing window is then used to write servo patterns onto the disk. Adjusting the timing window compensates for irregularities in the spiral servo signals.

Abstract: An optical tracking system is presented which aligns a recording head with a magnetic tape. The system relies on an optically detectable servo track on the back of the tape. The servo track is formed by repeatedly engraving, at spaced intervals, three co-linear marks perpendicular to the length of the tape. Laser light reflects off the marks, and passes through a ball lens that directs the reflected light on to separate light detectors, one for each mark. By recording characteristics of the reflected light, the detectors transmit information to the system that permits the recording head to be properly aligned with the tape.

Abstract: Disclosed is a method for reducing spiral write time and clock reference drift while writing spiral reference patterns on a disk of a disk drive. The method includes: controlling a radial location of a head for writing a first band of tracks near one of an outer diameter (OD) circumference of the disk or an inner diameter (ID) circumference of the disk and for writing a second band of tracks near the other of the OD circumference of the disk or the ID circumference of the disk, respectively, wherein a substantial majority of the tracks each include a plurality of servo sectors including a track number and a sync mark; measuring a distance between first and second reference center positions of reference center tracks of the first and second bands of tracks; and writing a spiral reference pattern therebetween.

Abstract: A disk drive, such as a magnetic recording hard disk drive, has a head positioning servo control system that includes an improved repetitive controller included with the conventional feedback controller for suppressing periodic disturbances. The repetitive controller includes a low-pass filter (LPF) and a time-delay memory with a time delay matched to the period of the periodic disturbance. In a digital implementation, where the head position error signal (PES) is sampled, the time delay is the time for N samples. A subsequent PES sample is summed with the time-delay input sample from N samples earlier and this summed value is input to the LPF. The output of the LPF is added to the subsequent PES sample and the added value is input to the feedback controller. The value of N is adjustable, so the repetitive controller is adaptable to changes in frequency of the periodic disturbance.

Abstract: A method is applied to reduce a range in variation of a target spin speed for a rotatable medium in a data storage device. The method includes rotating the rotatable medium at the target spin speed, determining an initial position of a head relative to a surface of the rotatable medium, determining a target position of the head relative to the surface of the rotatable medium, calculating an adjusted spin speed based on the initial position and the target position, sending a signal to rotate the rotatable medium at the adjusted spin speed, repositioning the head from the initial position to the target position, and sending a signal to rotate the rotatable medium at the target spin speed.

Abstract: An apparatus for providing sector location pulses to a controller of a rotating disk data storage device having a counter clocked in proportion to the disk rotation rate and an accumulator for accumulating times to sectors on the disk. A comparator connected to the counter and the accumulator enables an accumulator clock for repetitive clocking of the accumulator at such times the contents of the accumulator do not exceed the contents of the counter. A sector location pulse generator connected to the comparator generates the controller pulses, when enabled, concurrently with the accumulator clock signals. A master reset generator resets the first counter and the accumulator each time an index location on the disk passes a transducer head used to read and write data to and from the disk and a partial reset generator resets the accumulator each time the transducer head is moved between tracks on the disk.