Abstract: A rotation disturbance compensation control unit applies a compensation signal to a positioning control unit so as to cancel out rotation disturbance vibration components detected by using acceleration velocity sensors. At predetermined timing, a position error detection unit detects respective position errors of the case in which the rotation disturbance compensation control unit is turned on and the case in which it is turned off. A compensation control switching unit switches the rotation disturbance compensation control unit to be on if the position error of the case in which the compensation control of rotation disturbance is turned on is small and switches the compensation control switching unit to be off if the position error of the case in which the compensation control of rotation disturbance is turned off is small.

Abstract: A retraction control unit controls a retraction of a head of a storage device to a retraction position apart from a ramp by a predetermined distance. When the head is retracted from the retraction position to the ramp, a speed control unit controls a speed of the head to ascend the ramp to be constant by outputting a preset control signal.

Abstract: A control device that controls a storage device having an auto-gain-control function for controlling strength of an output signal from a head that reads data from a storage medium, which includes a determining unit that determines whether the strength of the output signal controlled by the auto-gain-control function is within a predetermined range, an abnormal-float detecting unit that detects an abnormal float of the head based on a result from the determining unit, an abnormal-float-number counting unit that counts a number of times of the detected abnormal floats of the head, and an abnormal-float-count storing unit that stores the counted number of times of the abnormal floats into a storage area of the storage device.

Abstract: An amplitude measurement unit measures an amplitude of a read signal from a preamble unit in a servo area of a predetermined frame number m per one rotation of the recording medium for a predetermined cycle number n while increasing an electric power amount distributed to the heater in the state in which the head is positioned to a track on the recording medium, and a mean amplitude calculating unit calculates a mean amplitude from an amplitude measurement value which is measured by the number which is the frame number m multiplied by the cycle number n.

Abstract: A controller controls movement of a head mounted in a storage apparatus based on a signal output from an acceleration sensor. A head movement control section which controls movement of the head to a target position on a storage medium and a head unload control section unloads the head to an unload position based on (1) the time at which a drop or initial impact is first detected based on a signal output from the acceleration sensor and (2) threshold information, which includes a first threshold representing a standard strength of the signal output from the acceleration sensor at the time of drop and a second threshold representing a standard strength of the signal output from the acceleration sensor at the time of initially receiving impact.

Abstract: A control apparatus detects positional information of a head performing writing processing every predetermined time interval, and computes next-sample projected positional information of the head based on the difference between the positional information detected the previous time and the positional information detected the current time, and the current detected positional information for every position information detected. The control apparatus determines whether the computed next-sample projected positional information is greater than a next-sample projected position threshold which is a predetermined threshold. Following this, in the case that determination is made that the next-sample projected positional information is greater than the projected position threshold, the disk control apparatus controls a storage device to stop the writing processing after the writing processing is performed through the end of the sector wherein the writing processing is currently being performed.

Abstract: A data storage device executes sector guarantee processing at an unexpected power supply disconnection. The sector guarantee processing can be accurately performed even if the fluctuation of power supply voltage during normal operation is high. The voltage of the power supply is monitored via an A/D converter. The control unit calculates a voltage change value, which is a relative value of the detected voltage of the power supply, and judges power supply disconnection by the level of the voltage change value, to perform sector guarantee processing. The voltage fluctuation during normal operation and the voltage fluctuation at power supply disconnection can be distinguished, power supply disconnection can be accurately detected, and write disable status can be judged.

Abstract: A heater for changing a projection distance protrusion value by thermal expansion accompanying electric-power-distributed heating is embedded in a head having a reading element and a recording element. A clearance control information measurement unit measures and saves, at desired correction timing, clearance control information including a clearance required for controlling the clearance between the reading element and the recording medium, heater projection sensitivity protrusion sensitivity, projection distance protrusion value transition time, recording current projection distance protrusion value, and a temperature correction coefficient. The clearance control unit varies the electric power distributed to the heater and changes the projection distance protrusion value of the head, thereby controlling the clearance to a target clearance upon reproduction and recording.

Abstract: A head control device for controlling, through thermal expansion of a heater, a position of a head for reading and writing data from and to a storage medium, includes a heater control unit that increases a current supplied to the heater stepwise; and an external-force sample retrieving unit that retrieves sampling values of signals each indicating a magnitude of an external force acting on the head in a moving direction of a head support mechanism. The head control device also includes an external-force evaluating unit that calculates a representative value of the sampling values retrieved by the external-force sample retrieving unit to evaluate the magnitude of the external force every time the heater control unit increases the current; and a contact detecting unit that detects contact between the head and the storage medium by comparing each evaluation result by the external-force evaluating unit with a predetermined threshold value.

Abstract: A falling-time measuring unit measures time for which a fall of a storage device is consecutively detected by a fall detecting sensor. A head-position detecting unit detects a position of the head on a storage medium at a time of starting measuring the time. A moving-time calculating unit calculates necessary time for moving the head from the detected position to a destination position. A first-threshold determining unit determines whether the measured time exceeds a threshold calculated by a threshold calculating unit. A head-movement processing unit moves the head to the destination position when it is determined that the measured time exceeds the first threshold.

Abstract: A head-slap detecting device detects a head slap. The head slap causes a storage medium to be slapped by at least one storage-medium driving unit that performs at least one of reproduction and recording of data from and to the storage medium. The head-slap detecting device includes a detecting unit that detects the head slap by determining whether a first variable gain obtained from a variable gain amplifier that amplifies an output of data reproduced by the storage-medium driving unit exceeds a predetermined threshold.

Abstract: A falling-time measuring unit acquires information indicating whether a magnetic disk drive is falling, from a fall sensor at a predetermined sampling cycle, and measures a falling time based on the acquired information. A threshold changing unit counts number of times the measured falling time exceeds a predetermined fall-determination threshold within a predetermined time, and extends the fall-determination threshold when the counted number of times exceeds a predetermined maximum number of times. A head retracting unit retracts the head to the retraction position when the measured falling time exceeds the extended fall-determination threshold.

Abstract: A sample-information extracting unit acquires a fall signal indicating whether a storage device is falling, conducts a sampling in response to the fall signal, and sequentially extracts sample information including either one of first information indicating a falling state and second information indicating a non-falling state. A retraction determining unit determines whether to retract the head, based on features of an array of the extracted sample information.

Abstract: A storage apparatus rotates an optical recording medium at two or more kinds of rotational speeds. The rotational speed is decreased when a read or write margin becomes less than or equal to a first predetermined value or, when a frequency of generation of a servo abnormality of a tracking servo and/or a focus servo is greater than or equal to a first predetermined frequency. On the other hand, the rotational speed is increased when the read or write margin becomes greater than or equal to a second predetermined value or, when the frequency of generation of the servo abnormality of the tracking servo and/or the focus servo is less than or equal to a second predetermined frequency.

Abstract: An amplitude measurement unit measures an amplitude of a read signal from a preamble unit in a servo area of a predetermined frame number m per one rotation of the recording medium for a predetermined cycle number n while increasing an electric power amount distributed to the heater in the state in which the head is positioned to a track on the recording medium, and a mean amplitude calculating unit calculates a mean amplitude from an amplitude measurement value which is measured by the number which is the frame number m multiplied by the cycle number n.

Abstract: The present invention aims at providing an inexpensive optical information storing device that produces reduced cross talk. An optical information storing device has a cyclic data output circuit 14—1 that outputs cyclic data in which values are repeated every 5 bytes, and an EXOR circuit 14—2 that calculates the exclusive-OR (EXOR) of recording data input thereto via a buffer 14—5 and the cyclic data and inputs the calculation result to an RLL modulation circuit 14—3 as data to be recorded.

Abstract: A disk control apparatus controls a disk driving unit that performs read/write of data with a head. A vibration detecting unit detects a vibration of the disk driving unit. A disk control unit controls the disk driving unit based on the detected vibration.

Abstract: A falling-time measuring unit measures time for which a fall of a storage device is consecutively detected by a fall detecting sensor. A head-position detecting unit detects a position of the head on a storage medium at a time of starting measuring the time. A moving-time calculating unit calculates necessary time for moving the head from the detected position to a destination position. A first-threshold determining unit determines whether the measured time exceeds a threshold calculated by a threshold calculating unit. A head-movement processing unit moves the head to the destination position when it is determined that the measured time exceeds the first threshold.

Abstract: A control apparatus performs, when reading predetermined data stored in a storage medium, a correction of a signal read by a head during a Viterbi decoding process of the signal. A signal-quality-value calculating unit calculates a signal quality value of the signal based on a status of the correction during the Viterbi decoding process. A signal-quality-value storing unit stores the calculated signal quality value in a storage area.

Abstract: A retraction control unit controls a retraction of a head of a storage device to a retraction position apart from a ramp by a predetermined distance. When the head is retracted from the retraction position to the ramp, a speed control unit controls a speed of the head to ascend the ramp to be constant by outputting a preset control signal.