Samsung Electronics Co., Ltd.

Sang-hoon Chu

Cheol-hoon Park

Nam-guk Kim

Yong-gwon Lee

Chul Wan Park

Kyoung-whan Oh

Sung-Won Park

Kwang-jo Jung

Jong-yun Yun

Sung-won Park

Provided is an apparatus and method of adjusting reference clock frequency in a disk drive. The reference clock frequency adjustment method includes; measuring each servo sector detection time interval, generating an error signal by subtracting initially set reference time interval information between servo sectors from the measured servo sector detection time interval information, and adjusting the reference clock frequency using the error signal such that a constant number of reference clock pulses are generated in each servo sector detection time interval regardless of variation in each servo sector detection time interval.

Method and apparatus adjusting reference clock frequency and disk drive using same

A disturbance compensation determination apparatus, a related method, a computer readable medium storing a computer program related to the method, and a disk drive comprising the apparatus are provided. The disturbance compensation determination apparatus includes a disturbance observer (DOB) receiving a control input signal and a servo output signal of a plant, wherein the DOB calculates and outputs a current estimated disturbance value. The apparatus also includes a disturbance evaluation unit selectively changing a current disturbance compensation (DC) mode, wherein selectively changing the current DC mode comprises evaluating an accumulated estimated disturbance value in accordance with a condition corresponding to the current DC mode. In addition, the apparatus includes a switching unit selectively providing the current estimated disturbance value to a control loop of the plant in accordance with the current DC mode as selectively changed by the disturbance evaluation unit.

Disturbance compensation determination apparatus, a related method, a computer-readable medium storing a computer program related to the method, and a disk drive comprising the apparatus

A method of determining a size of an error generated in a servo sector, a write control method of controlling whether to write data to data sectors successive to a servo sector according to the size of the error generated in the servo sector therein, a HDD using the write control method, and a recording media storing computer programs for executing the methods. A method of determining a size of an error generated in a servo sector of a HDD includes: reading servo information from the servo sector in which the error was generated; and determining the size of the error by the number of corresponding bits that differ from each other between the read servo information and a normal servo information.

Method of determining size of error and write control method for hard disc drive, hard disc drive using the write control method, and media storing computer programs for executing the methods

Provided are an apparatus and method of controlling a motor by compensating for recurring false speed errors generated in a direct current (DC) motor. The apparatus includes a learning control unit adapted to calculate recurring false speed errors related to a mechanical tolerance associated with the motor in each one of a plurality of controlling sections associated with a single rotation of the motor, and generate a corresponding reference speed for each controlling section, and a motor control unit adapted to control the rotational speed of the motor in relation to a speed error defined by a difference between the reference speed for each controlling section and an actual measured speed of the motor for each controlling section.

Apparatus and method compensating recurring false speed errors in DC motor and disk drive adopting same

A hard disc drive (HDD) data read control apparatus, medium, and method reading data from a disc having non-uniform track-to-track spacing. The data read control method of the HDD, in which data is read from a disc including non-uniform track-to-track spacing, includes seeking a target track by adopting an off track amount applied to a previously followed track, and reading the data while following the sought target track. Accordingly, production yield can be increased by making failure processing unnecessary even if a track-to-track spacing of a HDD is non-uniform.

HDD data read control apparatus, medium, and method

A method and apparatus to safely repress disturbances from being applied to a system from the surroundings in which the system is used. The method of adaptively repressing disturbances includes estimating frequency components of a disturbance applied to a system in a user environment; and optimizing parameter values determining characteristics of a disturbance compensating servo control loop including a disturbance observer, based on the estimated frequency components of the disturbance.

Adaptive disturbance repressing method and apparatus, and disk drive apparatus using the same

A method, medium, and apparatus for controlling a spindle motor of a disk drive. Particularly provided is a method, medium, and apparatus changing a current gain of a spindle motor driver according to the operating environment of the spindle motor. The method of controlling the spindle motor, using the current gain change of the spindle motor driver, includes monitoring a spindle drive control signal indicating the operating environment of the spindle motor and changing a current gain of the spindle motor driver based on the indicated operating environment.

Method, medium, and apparatus controlling current gain change of a spindle motor driver

An apparatus, medium, and method to control a disk drive, and in particular, an apparatus, medium, and method controlling a disk drive to perform a seek mode at an optimum state with respect to an operational temperature. A seek servo control method considering temperature change in controlling a disk drive may includes determining a seek time considering a given seek length and operational temperature change in a seek mode, and generating position, velocity, and acceleration trajectories to move a transducer according to the determined seek time.

Apparatus, medium, and method with seek servo control considering temperature change

A method, medium, and apparatus controlling a hard disk drive, and particularly, embodiments include methods, media, and apparatuses compensating for torque variations with respect to temperature variations in a seek servo operation, compensating for differences between modeling torque constants, used for servo designing, and actual torque constants. The method includes controlling gain of a seek control loop to vary depending on a torque constant temperature compensation value corresponding to a measured temperature of the hard disk drive, the seek control loop generating a seek driving current to be applied to a voice coil in the seek mode.

Method, medium, and apparatus compensating for torque variations based on temperature

The present invention relates to a write control method of a hard disk drive, a hard disk drive adapting the method, and a recording medium storing a program for executing the method. The write control method of a hard disk drive having a disk where servo bursts are written radially comprises: generating a primary position error signals (PESs) with respect to a target offtrack based on a difference between servo burst signals read from two adjacent servo bursts; generating a secondary PES with respect to the target offtrack based on a sum of the primary PESs or a difference there between; determining whether both the primary PESs and the secondary PES are within a predetermined write bump limit; and performing a write operation at the target offtrack if both the primary PESs and the secondary PES are within the predetermined write bump limit, otherwise prohibiting the write operation.

Write control method of hard disk drive, hard disk drive adapting the method and recording medium thereof

A seek servo control method and device for a disk drive device for performing seek servo control according to a variation in a power supply voltage for the disk drive. The seek servo control method includes: detecting a supply voltage for the disk drive; and adjusting a seek time according to a track seek length based on the detected supply voltage.

Seek servo control method for adapting to supply voltage variation and disk drive using the same

A method, medium, and apparatus controlling a hard disk drive, and more particularly, a method, medium, and apparatus controlling a track seek of a hard disk drive, where the hard disk drive compensates for a gain distortion and a phase delay caused by a notch filter and a VCM driver using a sinewave acceleration trajectory. According to the method of controlling a track seek of a hard disk drive, an ideal sinewave for obtaining a position y*(n), a velocity v*(n), and an acceleration a*(n), according to a sinewave acceleration trajectory, and a sinewave indicating a gain distortion and a phase delay may be integrated and a VCM driving current u(n) can be generated by the integrated sinewave for compensating for gain distortion and phase delay, compensating for a value C(j2&#x3c0;f) of the gain distortion and the phase delay caused by the notch filter and the VCM driver.

Method, medium, and apparatus controlling track seek in a recording and/or reproducing apparatus

A method of testing quality of a servo burst signal recorded on a hard disk drive and a recording medium adapted therefor, the hard disk drive including a plurality of sectors within one track and the burst signals for servo control recorded radially on each sector. The method includes: detecting peak positions at a radial position in which amplitudes of the recorded burst signals peak respectively on each track; comparing the detected peak positions of the burst signals on each track; detecting peak position error count, the peak position error count being a number of tracks in which offset of the detected peak positions exceed an offset limit within a predetermined number of tracks; and if the peak position error count exceeds the offset limit, determining a write quality of the servo burst signal to be low. A servo burst signal recorded with uniform intensity and a servo burst signal recorded with shift from normal position can be detected. Therefore, the quality of a servo burst signal can be managed efficiently.

Method of testing servo burst signals of hard disk drive and recording medium adapted therefor

For unlatching a head within a data storage device, such as a HDD (hard disc drive), a VCM (voice coil motor) amplifier with a switch is used for applying at least one cycle of an acceleration current pulse to a voice coil motor (VCM) for unlatching the head during an acceleration time zone. An analog to digital converter samples a characteristic of the VCM for indicating a speed of the head during the acceleration time zone. An unlatch controller terminates the acceleration time zone when the speed of the head is higher than a threshold speed, for more stable operation of the head but with guarantee of unlatching, regardless of the latch force within the HDD.

Apparatus and method for unlatching a head within a data storage device

A method and apparatus to compensate for a difference between an actual torque constant and a modeling torque constant used for servo design in a disc drive. The method has operations of: performing predetermined test seeks with respect to test seek positions into which a disc is divided; obtaining torque compensation constants from the test seeks; storing the torque compensation constants in a torque compensation constant table; and compensating for a gain of a seek control loop at a position where a seek is performed in a seek mode, using the torque compensation constants stored in the torque compensation constant table.

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Yongin-si, South Korea

Sang-hoon Chu