Hitachi Global Storage Technologies Netherlands B.v.

International Business Machines Corporation

Hgst Netherlands, B.v.

Makoto Takase

Minoru Hashimoto

Kenji Okada

Hiroaki Suzuki

Kei Yasuna

Keishi Takahashi

Akira Kibashi

Kohji Takasaki

Yasuhiro Kotani

Tomoo Ozaki

Hideo Asano

Satoshi Yamamoto

Kenji Kuroki

Toru Aida

Fuminori Sai

Hiroshi Yanagisawa

Masaki Yoshioka

Takao Matsui

Toshiroh Unoki

Tatsuya Endo

Hiroshi Oshikawa

Keiji Kobayashi

Koji Kurachi

Ryohheita Hattori

Hiromi Nishimiya

Mariko Kado

Katsumi Suda

Takao Horiguchi

Xuchu Zhu

Wee Hei

A system and method of writing servo write tracks to a rotating disk using a head having a read/write offset is disclosed. One embodiment utilizes a write element on the head to write the servo write tracks. A read element on the head is then positioned over the servo write tracks. The phase of a specific frequency component of the track shape error in the servo write track is measured during the positioning of the read element over the servo write track. A sine wave having a specific frequency and a phase is selected based on the measurement results. The sine wave is then applied to a servo system as a correction signal. A new servo write track is then written with the write element.

Disk drive and method of writing servo write tracks to a disk

A method for forming servo patterns on a magnetic-recording disk. The method includes moving a magnetic-recording head in an opposite direction to a pattern development direction, when there is a faulty servo pattern. The method also includes positioning a write element of the magnetic recording head on a track of the faulty servo pattern and forming a reserve servo pattern at a different circumferential location from that of the faulty servo pattern. The method includes moving the magnetic-recording head in the pattern development direction. The method further includes positioning the read element on the track of the faulty servo pattern and forming a new servo pattern in the pattern development direction at the circumferential location of the faulty servo pattern on a track disposed between the track of the faulty servo pattern and an outside diameter of the magnetic-recording disk, based on data read from the reserve servo pattern.

Method and apparatus for forming servo patterns on a magnetic-recording disk

A method for writing servo sector sets that include a plurality of separate servo sectors on a disk so that servo sectors are present at same circumferential positions but different radial positions. The method includes reading a first servo sector set in a track with a read element such that the track includes first, second and third servo sector sets. The method also includes writing the third servo sector set with a write element at a different radial position from the read element with positional control and timing control using the first servo sector set while skipping the second servo sector set if all servo sectors of the first servo sector set are non-defective. Moreover, the method includes using positional control and timing control using the second servo sector set in the writing of the third servo sector set if the first servo sector set includes a defective servo sector.

Method for writing servo data to a disk and disk drive configured to write servo data utilizing the method

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 provide a method of testing/adjusting magnetic disk devices, in which the method allows the tests/adjustments to be conducted by solving problems due to the data sizes and characteristics of test/adjustment programs. After assembly of a magnetic disk device, setup of various parameters, magnetic disk defect registration, and other test/adjustment steps are executed. Execution of the test/adjustment programs does not require a special test apparatus since they are executed in the magnetic disk device to be tested. In addition, the test/adjustment programs are formed up of multiple phases, and each phase is sequentially executed. Adoption of this program structure keeps the tests/adjustments clear from restrictions due to the data sizes and characteristics of the test/adjustment programs.

Testing/adjusting method and test control apparatus for rotating disk storage devices

Embodiments in accordance with the present invention relate to suppressing effects of the rotational jitter of a rotating medium during self-writing of patterns on the medium. In one embodiment, patterns are written on a track TE first. While a clock frequency is modulated using the difference between the readout time and target time of each pattern PE on the track TE, patterns PF are written on a track TF after a calculated delay time from the readout of each pattern PE. During pattern writing on the track TF, any timing errors of the patterns PE are stored into memory. While the target time for each pattern PF on the track TF is being corrected using the stored timing errors of the patterns PE and the clock frequency is being modulated using the difference between the readout time and corrected target time of each pattern PF, patterns PG are written on a track TG after a calculated delay time from the readout of each pattern PF.

Magnetic disk drive and method for registering defective sector using timing control of pattern writing

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

When a host apparatus transfers/swaps stored information between user sectors in a storage device for the purpose of defragmentation or the like, the storage device is allowed to perform the data transfer or swap without transmission between the host apparatus and the storage device after the command is received by the storage device; and consistency in stored information identification is maintained between the host apparatus and the storage device even if the operation is interrupted. In one embodiment, information stored in the destination user sector LBA(Y) is copied to the dummy sector LBA(D), its entry is written in the mapping table RDM, information stored in the source user sector LBA(X) is copied to LBA(Y), and then the RDM entry is erased.

Fragmentation executing method and storage device

If the number of retries made before data is read successfully reaches or exceeds a predetermined number, the data is saved in spare sectors SS and then data sectors DS which originally stored the data are overwritten. Furthermore, both when data is saved in spare sectors SS and when data is written over data sectors DS, appropriate pointer information in RDM table stored in a reserved area RA including a nonvolatile memory is updated as required.

Recording and playing back device with error correction

A method and apparatus for recovering from operation errors arising in an information recording and reproducing unit using a head with a GMR sensor is described. The read and write operations of the unit comprise executing a first error recovery procedure for recovering the operation error, executing a first GMR evaluation procedure for evaluating the performance of the GMR sensor when the operation error cannot be recovered by the first error recovery procedure, and applying a resetting pulse to the GMR sensor in accordance with the first GMR evaluation procedure.

Error recovery in unit using GMR sensor

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Kanagawa, Japan

Makoto Takase