Fujitsu Corporation

Toshiba Storage Device Corporation

Nippon Telegraph and Telephone Corporation

Nippon Telegraph & Telephone Co.

Shigenori Yanagi

Takashi Masaki

Toru Ikeda

Takeshi Hara

Yukio Abe

Takahiro Aoki

Satoshi Furuta

Akira Minami

Tomonori Yamashita

Toru Fujiwara

Wataru Tsukahara

Shigeyoshi Tanaka

Satoshi Yamashita

Shinya Kobayashi

Atsushi Suzuki

Masaharu Moritsugu

Mitsuo Kamimura

Takao Abe

Yuji Karakawa

Toshio Kuriuzawa

Tadashi Sagawa

Osamu Yoshida

Manabu Yamamoto

Shigeru Arai

Masateru Sasaki

Hiroshi Tani

Toshitaka Iwamoto

Yoshifumi Obara

Masatsugu Nishida

Fumiya Kudo

Hiroshi Kumita

Kikuji Katoh

Hideshi Mochizuki

Shunji Saitou

Shunsuke Aoki

Masaaki Iwasaki

Yoshiaki Ikai

Kenichi Hamada

Miyozo Maeda

Teruji Yamakawa

Yoshiyuki Nanba

Takehiko Numata

Kiyomi Imamura

Yoshinari Higashino

Shunji Saitoh

Masaki Makifuchi

Makoto Takayanagi

Nobuyuki Nankumo

Tomoki Yokoyama

Hidenori Saitoh

Kazuki Kudo

Tetsuya Tabuchi

Tetsuya Tsuji

Syunji Saitou

Shigeko Kobayashi

Hidekazu Takata

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.

Storage device, control method, control device, and program

In a storage device, before activating a spindle motor (SPM) or continuously from activation until the SPM is stabilized at a target number of rotations, a voltage and temperature monitoring unit monitors the temperature in a disk enclosure unit and the voltage to be applied to an SPM driver. A current limit value calculating unit calculates an optimum current limit value not exceeding a rated current of the SPM driver, and a motor controlling unit controls the SPM driver and changes the current to be applied to the SPM so that the current does not exceed this optimum current limit value.

Storage device and method of controlling spindle motor of storage device

According to an aspect of an embodiment, an apparatus, includes: a medium having inner and outer edges and including first and second servo regions extending radially, and containing first and second servo information written thereon, respectively, the first servo region extending outwardly from the inner edge to cover tracks, the first and second servo region having positioned adjacently across a circular boundary; a head for reading out said first servo information and said second servo information; and a processor for executing a process comprising: reading out the first or second servo information; and when controlling the track position across the boundary, adjusting the relation of the first and second servo information across the boundary in control the track position.

Data storage device

A storage device receives and holds a storage medium that is subjected to first servo writing processing for writing servo information, a Gray code of which is offset, from an inner cylinder or an outer cylinder to a predetermined cylinder and, after the first servo writing processing, subjected to second servo writing processing for writing servo information from an opposite direction to the predetermined cylinder and in which Gray codes are written to be offset not to overlap in the first or second servo writing processing and the pieces of servo information having different mark patterns are written in the first servo writing processing and the second servo writing processing. The storage device acquires cylinder information and mark patterns from the servo information written in the held storage medium and controls a position of a head based on the acquired cylinder information and mark patterns.

Storage device and servo information writing method

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.

Storage apparatus, control method, and control device which enable or disable compensation control

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.

Controller, storage apparatus and control method

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.

Storage device, head returning method, and head returning apparatus

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.

Head control device, storage device, and contact detection method

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.

Control apparatus and storage device

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.

Control apparatus, storage apparatus, and writing control method

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.

Storage media having areas for storing data for correcting servo information errors

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.

Control apparatus, storage device, and head retracting method

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.

Head retracting apparatus, storage device, and head retracting method

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.

Medium storage device and medium rotation synchronization processing method for medium storage device

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.

Growing community of inventors

Kawasaki, Japan

Shigenori Yanagi