Hitachi, Ltd.

Hitachi Software Engineering Company, Ltd.

Hitachi Global Storage Technologies Japan, Ltd.

Akira Kojima

Tsuneo Hirose

Motoyasu Tsunoda

Hitoshi Ogawa

Yukari Katayama

Katsuhiro Tsuneta

Eisaku Saiki

Yasunori Kaneda

Terumi Takashi

Shoichi Miyazawa

Soichi Isono

Toshiyuki Haruna

Takashi Oeda

Masahiko Sato

Syoichi Miyazawa

Noriyuki Karasawa

Tetsuzo Kobashi

Fukashi Ohi

Akihito Ogino

Norikazu Takayama

Keiichiro Hirata

Minoru Ikeda

Yuichiro Kota

Mitsuru Kubo

Atsushi Takayasu

Yuji Yoshida

Kazunari Kose

Akio Shioya

Kunihiro Nunomura

Embodiments of the present invention reduce noise and residual vibration during random access operation of a magnetic disk drive. The magnetic disk drive which executes each instruction from an upper device to move a magnetic head from a start track to an end track on a magnetic disk. In one embodiment, the magnetic disk comprises a processor configured, if a seek span from the start track to the end track, according to a seeking instruction from the upper device, is equal to a preset specific length, to store the seeking instruction for the specific length in memory, and to seek an alternative position from the start track for moving the magnetic head and then seek the end track specified in the stored seeking instruction from the alternative position for moving the magnetic head.

Magnetic disk drive

A video camera is disclosed which can make photographing without any compulsion. A rotary grip is provided on a side face of a camera body so as to be rotatable relative to the camera body, the camera body having an image pickup device, a camera lens and a circuit board of various circuits. A hand strap is attached to the rotary grip. For carrying the video camera, the fingers other than the thumb of one hand are inserted between the rotary grip and the hand strap so that the tips thereof are caught on a peripheral surface of the rotary grip. A liquid crystal display monitor and an operating unit are integral with the peripheral surface of the rotary grip, and when the rotary grip is rotated relative to the camera body unit, the hand strap, as well as the liquid crystal display monitor and the operating unit, also rotate. Thus, the direction of the liquid crystal display monitor and that of the operating unit can be changed with respect to a photographing direction, and it is also possible to change the way of carrying the video camera.

Video camera with a rotatable grip unit

Heretofore, when an error occurs during data reproduction, a retry is repeated until the error is corrected, which leaves a possibility of data transfer being not completed within a specified time. Only one piece of error information on uncorrected errors is informed to a host system even if the errors have occurred in a plurality of unit data. To solve the problem, a magnetic disk drive is provided which can transfer data within a specified time because the number of retries executed when errors occur is limited to a range that data transfer can be finished within a specified time. The disk drive generates error information regarding all errors caused in reproduction and communicates error information along with reproduced data to a host system. The disk drive is capable of concurrent execution of data processing that allows of errors and data processing that does not allow of errors without demanding that the disk drive be furnished with high performance.

Management method for reproduction error and a disk drive making use of the management method

Retrying processing in access of data having different properties required such as reliability and real time property of the access is optimized. In a magnetic disk apparatus connected to a host computerthrough a connection interface and including a magnetic disk controller and a magnetic disk, the magnetic disk controller includes a retrying table in which an area address, an area size, a retrying limit value and the like are set for each of a plurality of storage areas A, B and the like of the magnetic disk and the retrying limit value set in the retrying table from the host computer is used to optimize the retrying processing for data having different reliability or real time property of access such as management data and image/audio data stored in each of the storage areas A, B and the like individually.

Storage apparatus and control method thereof

Retrying processing in access of data having different properties required such as reliability and real time property of the access is optimized. In a magnetic disk apparatus connected to a host computer through a connection interface and including a magnetic disk controller and a magnetic disk, the magnetic disk controller includes a retrying table in which an area address, an area size, a retrying limit value and the like are set for each of a plurality of storage areas A, B and the like of the magnetic disk and the retrying limit value set in the retrying table from the host computer is used to optimize the retrying processing for data having different reliability or real time property of access such as management data and image/audio data stored in each of the storage areas A, B and the like individually.

A magnetic disk recording and reproducing apparatus comprising a unit for inserting an error correcting code related to control information into said control information on data; a recording control unit for recording in a plurality of sectors formed by dividing the recording area of a magnetic disk, each sector having an ID area for recording said control information and a data area, provided adjacent to and behind said ID area, for recording said data; and a error correcting unit for correcting said control information of said ID area by said error correcting code before data is read from said data area corresponding to said ID area or data is recorded in said data area corresponding to said ID area.

Method and apparatus for recording and reproducing disk-type recording medium with dual head including reading head and writing head having offset cores

A disk storage device includes a data transfer control device for transferring data from a higher rank device to a storage medium and transferring data from the storage medium to the higher rank device, an identification device having identification information for determining whether it should be permitted or inhibited to write data into a predetermined recording area of the storage medium, and a data transfer command device, responsive to a data recording command given by the higher rank device, to order the data transfer control device to write data into the storage medium according to the identification information of the identification device. In response to a data write command given to the storage medium by the higher rank device, the data transfer command device collates a state of the data write command with the identification information possessed by a predetermined sector of the storage medium. When the identification information indicates data write inhibition, the data transfer command device does not order the data transfer control device to transfer data to the storage medium.

Disk storage device having identification information for protecting stored data

A recording apparatus includes a plurality of ECC units operating selectively and independently. A medium access unit reads data from a recording medium in a read mode, and writes data from a host device to the recording medium in a write mode. The data read out from the recording medium contains a reproduction data and a medium reproduction check symbol added to the reproduction data, and data written contains a recording data and a medium recording check symbol added to the recording data. The reproduction data or the recording data is stored in a buffer. In a read mode, the reproduction data from the medium access unit is transferred to the host device through the buffer and in the write mode, the recording data from the host device is transferred to the medium access unit through the buffer. Each ECC units detects any error of the data stored based on the check symbol added to the data stored in the buffer during the transfer operation, corrects the data stored when the error is detected, and generates a check symbol from the data transferred. The check symbol generated is transferred to a destination of transfer after the data to be transferred.

Recording apparatus

A disk type recording and reproducing apparatus includes a disk type recording medium having a plurality of tracks and having stored on each of the plurality of tracks a position signal indicating positions on the tracks; a drive section for rotating the disk type recording medium; a dual head separately incorporating a reading head for reading from the disk type recording medium and a writing head for writing into the disk type recording medium; a head drive section for moving the dual head; means for controlling the head drive section by a controlled variable in compliance with a position signal read from the disk type recording medium using an object track and the reading head; and memory means for storing quantity information used to correct the controlled variable of the means for controlling the head drive section. The means for controlling the head drive section, at least in a writing operation, obtains the controlled variable of the head drive section according to the position signal read from the disk type recording medium using the object track and the reading head and the quantity information stored in the memory means.

A disk type recording and reproducing apparatus includes a disk type recording medium, and a dual head including a reading head and a writing head. A center of the core of the reading head is shifted in the radial direction of the disk type recording medium relative to a center of the core of the writing head. The disk type recording medium has a plurality of recording tracks each having a plurality of sectors. Each of the sectors has an ID division provided ahead of a data division disposed in the circumferential direction of the disk type recording medium. The ID division has recorded therein identification information identifying the sector. A center line of the ID division is shifted in the radial direction of the disk type recording medium relative to a center line of the data division by a distance equal to a distance by which the center of the core of the reading head is shifted in the radial direction of the disk type recording medium relative to the center of the core of the writing head. The data division has identification information identifying the sector stored in a position ahead of data to be recorded and reproduced.

Method and apparatus for recording and reproducing disk-type recording

A disk drive has two channels of upper interfaces, and one channel is connected to a disk array controller, and the other channel is connected between a plurality of disk drives. A data disk drive reads the old data on the recording medium, calculates the exclusive OR of the old data and the corresponding data from the disk array controller, and transfers it to a parity disk as pseudo-parity data from the other channel. The parity disk drive reads the old parity data on the recording medium, calculates the exclusive OR of the old parity data and the pseudo-parity data, and writes it as new parity data.

Disk array subsystem and data generation method therefor

A rotary storage device includes a plurality of disk units, an upper-level interface circuit, a cache controller, a cache memory, and a control processor. In each disk unit, the storage area of each disk is subdivided into an ordinary user data area and a secondary cache data storage area including a group of consecutive cylinders. Data overflowed from the cache memory is sequentially written in the secondary cache data storage area so as to be later transferred therefrom to areas of the user data area according to addresses inherent thereto when traffic of upper-level input/output processing is relatively low. In the case of when data is sought to be accessed in the cache memory during a data read operation, access operations are performed first to the secondary cache data storage area and then to the user data area.

Rotary memory storage device with cache control method and apparatus

A magnetic disk recording and reproducing apparatus including a unit for inserting an error correcting code relating to control information in the control information, the control information relating to data, a recording control unit for recording the control information and the data in a recording area of a magnetic disk, the recording area having a plurality of sectors, each of the sectors having an ID area for recording the control information and a data area for recording the data, the data area corresponding to the ID area and being provided adjacent to and behind the ID area in the same sector as the ID area, and an error correcting unit for correcting errors in the control information in the ID area using the error correcting code before the data in the data area corresponding to the ID area and provided in the same sector as the ID area is read or recorded.

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Odawara, Japan

Akira Kojima