Abstract: A head retracting apparatus retracts a head on a storage medium upon detecting a fall. A counter-value calculating unit calculates a counter value that changes with an increase of a falling time and an increase of a non-falling time. A retraction determining unit determines whether to retract the head, based on the calculated counter value.

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 time measuring unit measures a duration time of a state relating to the detection of the abnormality when the head is retracted. A head-return determining unit determines whether to return the head onto the storage medium based on the measured duration time.

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: 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 fall sensor detects a fall of a storage device. A first moving unit moves the head to a predetermined position on a storage medium when a falling time exceeds a first threshold. A second moving unit retracts the head from the predetermined position to a ramp when the falling time exceeds a second threshold.

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 heater for changing a projection distance protrusion value by thermal expansion accompanying electric-power-distributed heating is provided in a head having at least a reading element. At desired correction timing, a changed distance detection unit measures a clearance changed distance in a state in which the head is positioned to a track on the recording medium while increasing the amount of electric power distributed to the heater. A contact determination unit determines that the head is brought into contact with the recording medium when a derivative value of the clearance changed distance is below a predetermined threshold value. A measurement output unit outputs the clearance changed distance detected by the changed distance detection unit at the time of contact determination of the contact determination unit as a measurement result of the clearance between the reading element and the recording medium.

Abstract: A magneto-optical recording medium device of the present invention optimizes a magnetic field forming the front mask and a magnetic field forming the rear mask by use of a single bias magnetic field generator, by shifting the peak position of the bias magnetic field in the magneto-optical recording medium device so as to deviate from the center of the laser beam spot in a tangential direction of the magneto-optical recording medium, enabling extended recording and reproduction margins.

Abstract: A disk testing apparatus that sets a predetermined condition of a recording density for a disk apparatus, and conducts a test relating to at least readout of data stored in the disk apparatus includes a condition relaxing unit that relaxes, when a result of the test is unsatisfactory, a condition of the recording density currently set for the disk apparatus to set a new condition of the recording density; and a re-testing unit that re-conducts the test on the disk apparatus to which the new condition is set.

Abstract: A rewrite verify processing unit rewrites read data on a sector requiring the number of times of retry equal to or more than a predetermined number of times during a process of reading a medium, and then perform a verify read. A rewrite verify managing unit records the sector processed by the rewrite verify processing unit and the number of times of processing on a rewrite verify management table, and assigns, and assigns the sector where the number of times of processing has reached a predetermined number of times to an alternative area for exclusion from a process target for a rewrite verify processing process.

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 storage medium includes tracks extending in a circumferential direction, user data areas formed on the tracks for storing user data, and servo frames corresponding to the user data areas and extending in a radial direction for storing servo data. Data correcting areas corresponding to the servo frames and extending in the radial direction adjacent the servo frames are provided for storing correcting data for correcting positional deviation of a read/write head resulting from an error in the servo data stored in the servo frames. The correcting data stored in the data correcting areas on the same track are separated by at least one correcting data area.

Abstract: A medium storage device writes or read data on a storage medium synchronizing the rotation of the storage medium with the DSW method for decreasing the gap length considering the rotation jitter. The medium storage device has a controller for generating synchronization timing signals during reading/writing from a clock, and a processing unit for calculating the correction value of the frequency from the measurement result of the servo synchronization mark space of the storage medium. The processing unit judges whether or not the detected interval of the servo synchronization marks is within a predetermined range which is not occurred a frequency compensation to influent an error rate when reading, and corrects the synchronization timing of the controller based on the interval of the servo synchronization marks when the detected interval is judged within the predetermined range.

Abstract: A medium storage device writes or read data on a storage medium synchronizing the rotation of the storage medium with the DSW method for decreasing the gap length considering the rotation jitter. The medium storage device has a controller for generating synchronization timing signals during reading/writing from a clock, and a processing unit for calculating the correction value of the frequency from the measurement result of the servo synchronization mark space of the storage medium. The processing unit judges whether the servo synchronization mark has been correctly detected and calculates the frequency correction value. Therefore changing the synchronization timing using the SSM interval detected in error can be prevented, and the danger of data corruption can be avoided.

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 write and/or erase method is adapted to a storage apparatus having a function of changing a write and/or erase power of a light beam with respect to a recording medium. The write and/or erase method sets a write and/or erase slice level for detecting an off-track of the light beam with respect to a track on the recording medium depending on the write and/or erase power.

Abstract: A recording medium and an information storage apparatus having high formatting efficiency are provided. The recording medium and the information storage apparatus give IDs for data to be stored. In one embodiment, one ID is provided for two data areas, and no two IDs are situated in line with each other on two adjacent tracks.

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.