International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Nippon Telegraph and Telephone Corporation

Canon Kabushiki Kaisha

Renesas Electronics Corporation

Hgst Netherlands, B.v.

Mikuni Corporation

Hitachi Global Storage Technologies

Hitachi Global Technologies Netherlands B.v.

Kenji Okada

Minoru Hashimoto

Hideo Asano

Satoshi Yamamoto

Hideki Ohzeki

Tetsuo Ueda

Fuminori Sai

Akira Kibashi

Makoto Takase

Koichi Arai

Sri Muthuthamby Sri-Jayantha

Hiroaki Suzuki

Hien Phu Dang

Arun Sharma

Naoyuki Kagami

Akira Tokizono

Keishi Takahashi

Tatsuya Endo

Chikako Sasaki

Gordon James Smith

Yasuhiro Suzuki

Hiroshi Uchida

Tetsuo Semba

Yushi Mikuriya

Kenji Kuroki

Isao Yoneda

Kazumi Yoshizaki

Toshiyuki Hakata

Kinya Ohtani

Masakazu Sasaki

Noriki Miki

Kiyomi Kumozaki

Takao Matsui

Mirei Hosono

Kazuhisa Shishida

Kohji Takasaki

Yasuhiro Nishimura

Nobuyuki Tokura

Yasuhiro Kotani

Koji Kurachi

Hiroshi Oshikawa

Hiromi Nishimiya

Kazushige Okutsu

Katsuhiko Ohta

Masaaki Fukugauchi

Chikako Sakagami

Akinori Yuba

Masayuki Takeuchi

Takahiro Saitoh

Katsumi Suda

Tatsuya Endoh

Hiroomi Kakihara

Noriaki Mukaide

Koichi Takeuchi

Kunihiro Kaneko

Fumio Mano

Hisashi Kakuta

A semiconductor device SD includes a substrate SUB, a plurality of gate electrodes GE, a gate pad GEP, and gate interconnects GINC. The plurality of gate electrodes GE are formed in the substrate SUB, and extend electrically in parallel to each other. The gate pad GEP is formed in a region different from that in which the plurality of gate electrodes GE are formed in the substrate SUB. Each of a plurality of gate interconnects GINC connects the plurality of gate electrodes GE to the gate pad GEP.

Semiconductor device having a plurality of transistors connected in parallel

A disk drive. The disk drive includes a head, an actuator, and a controller. The head accesses a disk. The actuator is configured to support the head and to move the head by action of a voice-coil motor in a substantially radial direction of the disk. The controller is also configured to perform servo control of the actuator by using servo data read out by the head. The controller includes at least one of a plurality of notch filters having a fixed center frequency inserted in a servo-control loop. The controller is configured to increase an attenuation rate by at least one of the plurality of notch filters having the fixed center frequency at a designated frequency, when a target position of the head is at a position selected from the group consisting of a position outside of a specified region and a position within the specified region.

Disk drive and servo-control method therefor

One end of a humidify elementwhich has a plurality of humidify segmentsconnected to be free to extend and contract is fixed to a first case portion. One end of another humidify elementhaving the same structure is fixed to a second case portion. Each other end of the two humidify elementsis connected by a connect member. An inner spaceas a water reservoir is formed at the first case portionand the second case portion. At the time of non-usage, the first case portionand the second case portionare closed, and the humidify elementsand the connect memberare stored in the inner space. At the time of usage, the first case portionand the second case portionare opened, and the humidify elementsare extended. By supplying water to the inner space, one end of the plurality of humidify segmentsis soaked in the water, and the whole humidify elementis moistened by capillary.

Natural evaporation humidifier, humidifying element of the humidifier, and case for the humidifier

A file is transferred directly between a parent magnetic-disk device and a child magnetic-disk device. In one embodiment, a parent magnetic-disk device has a host-mode execution program, whereas a child magnetic-disk device is capable operating in a device mode as is the case with an ordinary magnetic-disk device. The parent magnetic-disk device has an operating-mode-setting unit including a special-purpose jumper block. An MPU employed in the parent magnetic-disk device executes the host-mode execution program to put the parent magnetic-disk device in a host mode. At an activation time, the MPU refers to the logic of the special jumper block to start an operation in the host mode. The MPU controls the parent magnetic-disk device to directly transfer a file to the child magnetic-disk device. Thus, the file can be transferred between the parent and child magnetic-disk devices without intervention by a host computer.

Storage devices and method of transferring file between the devices

Embodiments of the invention relate to writing servo patterns onto a recording disk with a high degree of accuracy and with correct phases in a servo-pattern-writing process. An In-Drive SSW (TSSW) process is processing to write product servo patterns onto a recording disk on the basis of time aligned patterns. In the processing to write product servo patterns onto a recording disk, time intervals between time aligned patterns already written on an ID-side track are measured, and timings to write the product servo patterns onto the recording disk on the basis of the measured time intervals are determined. Product servo patterns are then written onto an OD-side track with the determined timings relative to detections of the time aligned patterns used as references. In this way, circumferential-direction positions of product servo patterns written on a track may be aligned to the corresponding circumferential-direction positions of product servo patterns written on an adjacent track.

Method of writing patterns using head with correct phases, and data storage device

Embodiments of the invention relate to measuring characteristics of a head with an actuator put in a state of being pushed against a crush stop. In one embodiment, with a head placed on an innermost ID side or with the current of a VCM sustained at a magnitude I_mid, a burst pattern is written onto a recording disk. At this stage, the gain of a VGA is equal to its maximum value Gmax. Then, while the current of the VCM is being changed gradually, the gain of the VCA is measured. As the current of the VCM becomes equal to a magnitude I_center, a read element of the head is positioned right above the burst pattern. At that time, the gain of a VGA is equal to its minimum value Gmin. As the read element is further moved to the OD side, the gain of the VGA again becomes equal to the maximum value Gmax. A read/write offset of the head is identified by the magnitudes I_center and I_mid.

Method of measuring head characteristics of a data storage device, and data storage device

Embodiments of the invention provide a disk drive that may perform part of a function assignment process without being connected to a special test apparatus. In one embodiment, servo data is written only into dedicated regions of a disk. A function assignment program is stored within the dedicated regions. When a processor is powered on, the processor refers to a state setter and judges whether the function assignment program is to be executed. The state setter is constituted by a nonvolatile memory or a jumper block. The function assignment program includes data relating to servo data writing based on a self-servo writing scheme, and data relating to parameter setup.

Magnetic disk drive with function assignment and manufacturing method therefor

Embodiments of the invention provide a hard disk drive that is capable of performing degaussing promptly and properly and a recording method for use with such a hard disk drive. A hard disk drive according to one embodiment of the present invention comprises a current source for supplying a first current, which flows to a write head for writing data onto a magnetic disk; a current source for supplying a second current, which flows to the write head when the polarity of the first current changes; transistors for reversing the polarity of a current flowing to the write head; and a control circuit for exercising control so that the second current Iwhich flows from the current source to the write head when the polarity of the first current Iis reversed, becomes approximately zero before the first current Iconverges to approximately zero during a degauss period.

Degauss waveform generator for perpendicular recording write head

Embodiments of the invention relate to writing servo patterns having aligned phases onto a recording disk in a process to write the servo patterns onto the disk. In one embodiment, time aligned patterns are written onto a magnetic disk on the basis of time intervals between base patterns with timings aligned to each other throughout tracks on the disk. The time aligned patterns are written onto typically servo tracks at time intervals Ts with aligned timings. Then, on the basis of these time aligned patterns, product servo patterns are written onto the disk. A time aligned pattern is written onto the disk after the lapse of a predetermined write time period since detection of a base pattern corresponding to the time aligned pattern. The write time period is determined on the basis of time intervals between base patterns on adjacent tracks.

Method of writing patterns onto a recording disk, and data storage device

Embodiments of the present invention relate to detecting a flying high state in which a head/slider is flying stably at a high flying position, and then to restore the head/slider to a normal flying position. The detection is made by detecting a read output of a head using a head output detector, and by detecting a gain of a VGA using a gain detector. A control unit uses a value measured in a normal flying state as a reference value to compare a detected value with the reference value. If the compared values differ from each other, the control unit judges that a flying high state has occurred. The control unit, therefore, moves the head/slider to the vicinity of the innermost circumferential track of the disk, or unloads the head/slider.

Bi staple flying height detection by BEMF control profile and data integrity problem protection

An apparatus and method of controlling an actuator of a data storage device detect and/or correct narrowband mechanical excitations such as due to spindle bearing defects through sensing and/or rejecting disturbance frequencies associated with such narrowband mechanical excitations in an actuator control signal generated by a data storage device controller. A narrowband filter may be used to reject, from an actuator control signal generated by a data storage device controller, a disturbance frequency associated with a spindle bearing defect in a data storage device, and disposed in proximity to a zero crossover frequency associated with the data storage device controller. In addition, a peak filter disposed in a control loop of a data storage device controller may be configured to detect a spindle bearing defect in a data storage device by detecting an amplitude of a control signal in the control loop in proximity to a disturbance frequency associated with the spindle bearing defect.

Self-monitoring and self-healing of frequency specific position errors in a data storage device

A control arrangement having a feedforward system and a feedback system, a control model for generating reference position data from a feedforward control signal is separated into an original control model and a compensation filter. Gain of the feedforward control signal is compensated by a gain compensation circuit to form a feedforward control signal after compensation. The reference position data is input to a feedback controller, and a feedback control signal and feedforward control signal are input to a control object. Coefficients of the compensation filter and the gain compensation circuit are compensated on the basis of a head position trajectory obtained by actual seek operation.

Rotary recording apparatus and method of controlling the apparatus

To provide a disk drive, a manufacturing method thereof, and a disk-drive controller which are capable of improving yield without increasing costs so significantly. When track-following control is performed, HDC detects the current position of a read/write head, based on the reproduced output of a servo sector from a channel unit, and makes a calculation of servo data by employing both an integral parameter corresponding to a target track to be read onto a RAM and the detected current position of the read/write head.

Method of using an integral parameter for correct placement of a read/write head

A disk drive seek control system device to reduce track pitch. When data is recorded, an offset value is added to the position of a read head element along the width of a track corresponding to an offset &Dgr;w between the read head element and a write head element. The value of the offset depends on the yaw angle &thgr; of the head. When data is read, the position of the read head element is chosen to be either the position of the write head element during write operations, or the midpoint between the position of the write head element and the read head element during write operations, or the center of a track.

Method and apparatus for disk drive seek control

A method and apparatus for adaptive resonance cancellation in a rotating storage system, includes designing a set of digitally selectable optimum resonance cancellation filters, generating a series of excitation signals for injection into the filters, generating a characteristic resonance frequency based on the excitation signals, and computing an address pointer corresponding to the resonance frequency, to select an optimum resonance cancellation filter.

Method and apparatus for adaptive resonance mode cancellation servo in a rotating storage system

Growing community of inventors

Kanagawa, Japan

Kenji Okada