Abstract: The present disclosure provides a vibrator driving method, including steps of: obtaining a preset vibration frequency and a resonant frequency of a target vibration motor; obtaining total harmonic distortion of the target vibration motor; obtaining at least one low distortion point of the target vibration motor according to the total harmonic distortion; obtaining a target vibration frequency according to a low distortion frequency of at least one low distortion point and the preset vibration frequency; driving the target vibration motor to vibrate according to the target vibration frequency. The present disclosure further provides a vibration driving system and a vibration driving equipment.

Abstract: A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of tracks. An operating seek time profile is generated as a function of a base seek time profile, wherein the seek time profiles define a seek time to seek the head radially over the disk by a seek length. A seek operation is executed to seek the head by a target seek length by at least generating a target seek time based on the target seek length and the operating seek time profile, and seeking the head the target seek length based on the target seek time.

Abstract: A disk drive is disclosed comprising a voice coil motor (VCM) configured to actuate a head over a disk. The VCM is controlled to seek the head over the disk during a first seek, and a back electromotive force (BEMF) voltage generated by the VCM during the first seek is measured. Feed-forward compensation is generated based on the measured BEMF voltage, and the VCM is controlled to seek the head over the disk during a second seek using the feed-forward compensation while writing servo data to the disk.

Abstract: A disk drive is disclosed comprising a disk comprising a plurality of tracks, wherein each track comprises a plurality of data sectors and a plurality of servo sectors, and each servo sector comprises a plurality of servo bursts. The disk drive further comprises a head actuated radially over the disk, wherein the head comprises a dynamic fly height (DFH) actuator. A gain control circuit is operable to generate a gain control signal for adjusting an amplitude of a read signal emanating from the head. Control circuitry selects an operating control signal applied to the DFH actuator by positioning the head over one of the tracks, and measuring an amplitude signal in response to the read signal. An amplitude variance signal is computed in response to the amplitude signal, and whether the head has contacted the disk is detected in response to the amplitude variance signal.

Abstract: Method and apparatus for mutably associating logical block addresses to physical blocks. A physical storage space is apportioned into one or more bands. A logical block address (LBA) from a logical space is assigned to one of the bands, and the LBA is mutably associated with a particular physical block (sector) at an associated physical block address (PBA) within the assigned band. Such mutable association preferably includes the writing of user data associated with the LBA to the associated physical sector. During a subsequent operation, user data associated with the LBA can be stored in a second physical sector in the assigned band. The physical storage space preferably comprises a magnetic recording medium, and some or all of the bands preferably utilize overlapping tracks. The logical space is preferably divided into sets of sequential LBAs, with non-adjacent sets assigned to the same band. Map data are used to track sector allocation status in each band.

Abstract: A plurality of sensors are used to sense disturbances in a data storage system. An adaptive gain component is associated with each of the sensors and provides a gain for each of the sensor signals. The gain of each sensor signal is adapted, individually, based on a correlation of each given sensor signal to the position error signal. This adaptation produces a position correction signal. The position correction signal is applied to a position signal that is used to position the reading and writing components and the storage medium relative to one another. This compensates for both rotary and linear vibration disturbances at the same time.

Abstract: The directory information on a file system recorded on an optical disc is cached onto a hard disk as a directory table. When accessing a file on the optical disc, a processor references the directory table so as to obtain information related to a position, on the disc medium, where the file to be accessed is located, without accessing the directory information on the optical disc. A disc I/O controller moves a pickup unit to the location indicated by the positional information on the file to be accessed and reads the data on the file. The pickup unit is used to detect signals from the optical disc.

Abstract: A content reproducing apparatus is disclosed which includes: a sensor; a discrimination circuit configured to discriminate whether a movement of a user is a first movement or a second movement based on a detection output from the sensor; a storage configured to store contents; a reproduction circuit configured to reproduce the contents; and a control circuit configured to supply the reproduction circuit with contents retrieved from the storage in accordance with a discrimination output from the discrimination circuit.

Abstract: According to one embodiment, there is provided a magnetic recording apparatus including a bit-patterned medium having a data area including magnetic dot rows each of which includes magnetic dots, a magnetic head having a width covering a plurality of magnetic dot rows, and an actuator configured to actuate the magnetic head in a cross-track direction. The magnetic dots included in a n-th magnetic dot row have a higher coercivity than the magnetic dots included in a (n+1)-th magnetic dot row.

Abstract: A hard disk drive with a circuit that can perform a seek routine by providing a seek current to a voice coil motor. The voice coil motor is coupled to a head that is coupled to a disk. The seek current provides a predetermined number of harmonics. The number of harmonics is a function of a seek length of the seek routine. By way of example, the seek current may include only a first harmonic for seek lengths less than 20,000 tracks, or only the first and second harmonics for seeks less than 40,000 tracks. The harmonics can be determined by plotting PES settle versus seek length for a hard disk drive.

Abstract: A relative movement is induced between a head and first and second recording tracks along the boundary between the first recording track and the second recording track. The first recording track includes first magnetic dots arranged in the down-track direction at constant intervals. The second recording track includes second magnetic dots arranged in the down-track direction at constant intervals identical to the intervals of the first magnetic dots. The second magnetic dots are dislocated in the down-track direction relative to the first magnetic dots. The positional information is generated to specify the position of the head based on the difference between a first output of signals read from the first magnetic dots and a second output of signals read from the second magnetic dots.

Abstract: A method of and an apparatus for detecting an actuator vibration, and a hard disc drive write control method of avoiding an effect due to the actuator vibration. The method of detecting an actuator vibration includes: obtaining a specified number of position error signal (PES) samples while following a track; performing a time-frequency conversion on the specified number of PES samples; and detecting a magnitude of a conversion coefficient indicating a magnitude of an actuator vibration, in a specified frequency band.

Abstract: A recording method for a disk device includes the following steps. Sequential data is written into the medium along the track in a predetermined radial direction. Information indicating an end position along the track where the end of the sequential data is written into is stored. The information is read when additional sequential data is to be written into the medium. The additional data is written from a position along the track next to the end position indicated by the information in the predetermined radial direction. The information is updated so as to indicate an end position along the track where the end of the additional sequential data is written into.

Abstract: A method of and an apparatus for detecting an actuator vibration, and a hard disc drive write control method of avoiding an effect due to the actuator vibration. The method of detecting an actuator vibration includes: obtaining a specified number of position error signal (PES) samples while following a track; performing a time-frequency conversion on the specified number of PES samples; and detecting a magnitude of a conversion coefficient indicating a magnitude of an actuator vibration, in a specified frequency band.

Abstract: A movement controlling unit performs movement control of a head toward a target track on a magnetic disk medium driving a head actuator, and a position controlling unit performs position control of the head actuator in accordance with proportional integral calculations such that a deviation of a head position relative to a track center is eliminated when the moving head arrives at the target track. A gain retaining unit retains an integral gain of the proportional integral calculations in an increased state during a predetermined retention time from the start of the position control, and a gain switching unit switches the increased integral gain smoothly to the original integral gain when the retention time has elapsed.

Abstract: In a data handling system having a radially-dependent track incongruity between data surfaces, at least some tracks are logically mapped so that tracks on different data surfaces correspond with one another. The correspondence is defined by the mapping so as to shorten an average headswitch seek. For example, a logical track mapping of first and second non-coaxial track sets can be defined so as to optimize a headswitch seek within each of many intermediate logical cylinders identified in the mapping.

Abstract: A method and apparatus for reducing seek acoustics in a disk drive using a variable-bandwidth low-pass filter is provided. The variable-bandwidth low-pass filter is used to adaptively shape a control signal supplied to a VCM for moving a head relative to a disk surface during a seek operation. The bandwidth of the variable-bandwidth low-pass filter is dependent upon head position relative to a target track.

Abstract: Techniques are described for accurately processing playback signals of time-based servo patterns recorded on a data storage medium. In particular, techniques are described for determining values for signal peaks within a playback signal of a time-based servo pattern by applying interpolation to data points in proximity to each of the signal peaks. At least three data points are identified in proximity to a desired peak to be detected within the playback signal. A value is calculated for the desired peak based on interpolation of the at least three data points. A playback signal of a time-based servo pattern may include a sequence of signal peaks. A time-based servo pattern may be detected based on lengths of time measured between consecutive peaks in the sequence of peaks. A position error signal (PES) may be generated based on the values calculated for each of the sequence of peaks.

Abstract: A method of and an apparatus for recording data on a hard disk drive, and a storage medium containing a program for executing the method. Data is recorded on a track in a recording region and an address of a next track to be recorded with the data is determined so that the next track to be recorded with the data is located more than one track away from the previously recorded track so that the recorded data has robustness to adjacent track erasure and overwrite erasure.

Abstract: The operation of the changing mechanism is set to enhance the intensity of the urging force if the acceleration sensor detects an impact. The head slider is urged against the surface of the recording medium with the urging force of a larger intensity. Accordingly, the head slider is allowed to keep contacting the recording medium irrespective of the impact. The head slider is thus prevented from jumping up from the surface of the recording medium. A collision is surely avoided between the head slider and the recording medium. In addition, the head slider is urged against the surface of the recording medium when the recording medium stands still. The head slider is completely prevented from dropping onto the recording medium.

Abstract: In a method for generating a confidence level of a position error signal (PES) component that is indicative of a quality of the PES component, a PES component is generated using position signal samples of a read back signal corresponding to a servo burst pattern. Next, a noise level corresponding to noise in the read back signal is extracted using the position signal samples. A confidence level is then generated based on the PES component and the noise level. A system for performing the method includes a transformation block, a position error signal (PES) component extractor, a noise extractor, and a confidence level generator. The transformation block is configured to receive position signal samples of a read back signal corresponding to a servo burst pattern taken at a sampling frequency. A transformed domain representation of the position signal samples is then generated by the transformation block based on the sampling frequency and the servo burst pattern.

Abstract: Improved deceleration control for a disk drive is provided. A deceleration profile is selected based on a present velocity (vi), a present position (xi) and a BEMF constant associated with a voice coil motor (VCM). A control signal is supplied to a VCM driver in an attempt to have a read/write head follow the selected deceleration profile. As new present velocities and new present positions are obtained, these steps are repeated until the seek operation transitions from the deceleration phase to a settle phase. 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: A head position control method controls the speed of the head using the position and the speed detected from the servo information on the disk and directly detects the head speed. The speed detection pattern is assigned to the servo area of the disk, and the speed of the head is detected at the frequency of the regeneration signal. Therefore the speed of the head can be directly detected at the timing of the servo reading. By this, information on the head speed can be obtained with less error. Since there is no delay in the speed detection, the phase margin of the control system increases and stability improves.

Abstract: Position information PosN and PosQ are compared and position information Pos1 and Pos2 in which influences of an error of a position sensitivity gain appear oppositely are calculated. Subsequently, a weight gain G1=M and a weight gain G2=(1?M) are obtained from the position information Pos1. A multiplication value obtained by multiplying the third position information Pos1 by the weight gain G1 and a multiplication value obtained by multiplying the fourth position information Pos2 by the weight gain G2 are added and synthesized, thereby calculating a decoded position.

Abstract: A servo system is disclosed which is applied to a disk drive for detecting characteristic frequency components of a position error between a position of the head and the target position, and calculating a control correction value for correcting a control value. The servo system estimates the frequency components of target value variation from the characteristic frequency components of the position error, thereby modifying the characteristic frequency components to follow the target value variation. Thus, the servo system calculates the control correction value for suppressing the target value variation, and executes head positioning control, using a value obtained by adding the control value to the control correction value.

Abstract: An information handling system includes a processor and a disk drive coupled to receive information from the processor. The disk drive is configured to write the information to a first location on a platter. The disk drive is further configured to write the information to n locations on the platter such that a phase difference between successive locations is approximately (360 divided by n) degrees where n is an integer greater than or equal to two.

Abstract: A microactuator comprises a stator, a rotor and an operator coupling the rotor to the stator. The operator comprises a four-block magnet array supported by either the stator or rotor, and first and second coils supported by the other of the stator or rotor. Current in one coil alters magnetic flux linkage to move the rotor along a first axis. Current in the other coil alters magnetic flux linkage to move the rotor along a second axis orthogonal to the first axis. The microactuator is applied to the slider of a disc drive to position the head at a selected flying distance adjacent the disc medium, and to position the head relative to a track on the medium.

Abstract: A disk drive is disclosed comprising a voice coil motor (VCM) driver including an H-bridge driver having a first sense resistor connected in series with a supply voltage and a second sense resistor connected in series with ground. First and second amplifiers amplify the voltages across the first and second sense resistors, wherein the output of the amplifiers drive respective first and second oscillators. A counter processes the frequency signals output by the oscillators to generate a digital representation of the current flowing through the voice coil of the VCM.

Abstract: A disk drive is disclosed comprising a voice coil motor (VCM) for actuating a head radially over a disk. A VCM driver comprises first and second transistors forming a common collector amplifier for sensing a current flowing through a voice coil of the VCM. The common collector amplifier improves the accuracy of the current sense measurement when the VCM is driven in a pulse width modulated (PWM) mode.

Abstract: Apparatus and method for improving disc drive performance by compensating for head-to-head offsets when scheduling a plurality of pending access commands. A disc drive includes a plurality of recording surfaces on which a plurality of concentric data tracks are defined. A servo circuit performs seeks to move a plurality of heads from an initial track to a destination track. A positional offset between each of the plurality of heads is measured and applied to an estimated seek length to calculate a corrected seek length. A corrected seek time is calculated from a seek profile table in relation to corrected seek length. The corrected seek time is used by a control processor to schedule the access commands stored in the memory.

Abstract: A seek pattern formation circuit includes a seek pattern generation circuit for generating a seek pattern formed of a predetermined pulse train every time a step pulse is applied and a seek pattern shaping circuit for shaping the seek pattern and supplying the shaped seek pattern to a stepping motor driver. When the period for which the step pulse is supplied is shorter than the period for which the seek pattern is generated, and when at least one of pulses included in the seek pattern is very narrow, the seek pattern shaping circuit selectively eliminates the narrow pulse. As a result, narrow pulses which may induce noise are not supplied to the stepping motor driver, and hence a malfunction in the stepping motor driver does not occur.

Abstract: A method of writing to a disc in a disc drive includes receiving data to be written to a designated area of the disc wherein the designated area has a beginning, an end, and contains a defective portion. The data is written to the disc starting from the beginning of the designated area and proceeding toward the end of the designated area. The data is written to a temporary buffer, external to the disc, upon reaching the defective portion of the designated area. Writing is then resumed, writing data to the designated area of the disc, upon passing the defective portion of the designated area.

Abstract: The present invention relates to an information storage apparatus for storing information in a recording medium and to a data transfer method. A particular object of the present invention is to provide an information storage apparatus and a data transfer method, which realize a high-speed transfer of control parameters without deteriorating performance of a control operation. The present invention includes an automatic transfer processing part 102 which transfers control parameters stored in a memory 15 by DMA transfer to an RDC 9, a servo information demodulation circuit 10, a head IC 8, and a DSP 17. The memory 15 is connected to an MCU 101 which controls a read/write operation of a magnetic disk unit 100.

Abstract: When writing to a hard disk drive, an effective track skew is used which differs from the track skew used when reading from the disk. During reads from the disk, the disk controller uses a traditional logical track layout and logical block address (LBA) numbering having a track skew value related to read settle time. A different effective track skew value, optimized for write settle time, is used, however, when writing to the disk. Logical blocks are written to the disk out-of-sequence in order to accommodate this different effective track skew value.

Abstract: A power saving method and apparatus while maintaining an operational or near-operational state for computer memory disk drives. A microprocessor implements microcode instructions to determine if a disk drive is inactive. This is done by checking a control unit through an interface to see if any files are currently opened or data is being transferred by the disk device. If no files are opened and/or no data transfers are occurring, the drive is considered inactive. If the inactive period continues for a period of time which is greater than a predetermined reference activity level, then actions are taken to reduce the rotational velocity of the drive spindle motor to its lowest operational level, or just below the lowest operational level without stopping the disk. The spindle motor is accessed by the microprocessor through a spindle motor control unit.

Abstract: A disk drive with the capability to prevent off-track writing with reduced false triggering is described. An improved method of predicting the position of a head is used to determine whether the head is on or off-track. A position error signal at an nth servo position Pn and a velocity Vn at the nth servo position (Vn=Pn−Pn−1) are calculated using values read at the nth and n−1 head positions. Based on these Pn and Vn and on the output of the servo controller at the nth servo position Un, the predicted PESn+1 is calculated as: Predicted PESn+1=Pn+Vn+kUn where k is a constant.

Abstract: A disc drive includes a base and a disc rotatably attached to the base. The disc drive also includes an actuator assembly rotatably attached to said base and a device for moving the actuator assembly. The disc drive includes servo circuitry and a controller for controlling movement of the actuator and head switches during track seek operations. The disc drive determines the average seek time for each head and also measures the amount of time for a head switch from the transducer head having the shortest average seek time to all the other transducing heads in the disc drive. When a seek is performed, the controller in the disc drive determines if the shortest average seek time plus the seek time from the transducing head to the transducing head on the surface containing the target track and sector is less than the average seek time of the head on the surface having the target track and sector.

Abstract: This invention discloses a data access system for access data stored on a flat medium. The data access system includes a pickup head rotating over the flat medium. The data access system further includes at least one stepping motor for discretely moving the flat medium substantially along at least one lateral direction perpendicular to a rotational axis of the pickup head. The data access system further includes a closed loop control mechanism for controlling the stepping motor for allowing the pickup head to read data from a servo segment on the flat medium. The controller further includes an open loop control mechanism for rotating the pickup head for reading data from and writing data to a data segment disposed right next to the servo segment on the flat medium.

Abstract: A servo control system for a voice coil motor including a servo controller using position feedback to provide an acceleration current to the voice coil motor and voice coil brake providing a deceleration current based upon velocity feedback from the voice coil motor. In one embodiment, the velocity of the voice coil motor is derived from current feedback. A method for braking an actuator driven by a voice coil motor including the steps or receiving and processing current feedback from the voice coil motor and supplying a deceleration current to the voice coil motor derived from the current feedback from the voice coil motor.