Hitachi, Ltd.

Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Takayuki Kinoshita

Takato Ogiwara

Hiroshi Uchida

Naganori Koshimizu

Tetsuya Tamura

Tomonori Mouri

Hiroshi Oshikawa

Hiroshi Deki

Storing data in a hard disk drive may include determining a percentage of storage usage (SU %) of the data tracks. If the SU % is less than a first threshold percentage (TP1), the method may include storing data to Nth data tracks. If the SU % is greater than or equal to TP1, but less than a second threshold percentage (TP2), the method may include storing data to about N/2 data tracks between said Nth data tracks. If the SU % is greater than or equal to TP2, the method may include storing data to data tracks between said N/2 data tracks and said Nth data tracks.

System, method and apparatus for data track usage sequence to reduce adjacent track interference effect

A master cylinder includes a bottomed cylindrical cylinder body, a piston formed into a bottomed cylindrical shape by a forging method and slidably disposed in the cylinder body, and a spring assembly including a spring urging the piston toward an opening side of the cylinder body. A length of a spring of the spring assembly is determined by a retainer which can abut against an inner bottom portion of the piston. An annular groove is formed on the outermost side of the inner bottom portion of the piston by the forging method.

Master cylinder

In a master cylinder, a supply passage for supplying operating liquid from a reservoir () to a pressure chamber () is provided in a cylinder body () coupled with the reservoir. A bypass passage () for bypassing the supply passage and connecting the reservoir and the pressure chamber is further provided, and a check valve () adapted to open when a pressure in the pressure chamber is lower than that in the reservoir is disposed in the bypass passage. A valve case () containing a valve body () of the check valve includes a valve seat () and a cylindrical wall () for slidably guiding the valve body which are integrally formed as a single member.

A head position estimator estimates the present position of a head relative to a recording medium, an LBA calculator for calculating positions of a data block to be read next and other data blocks existing before and after the data block, and a moving destination determiner for determining a data block at which the time required to move the head is the shortest, as a data block to be read next, on the basis of the present position of the head, which has been estimated by the head position estimator, and the positions of the respective data blocks, which have been calculated by the LBA calculator.

Recording and reproducing apparatus, content reproducing apparatus, magnetic disk device, and control method thereof

A master cylinder designed to facilitate an operation of assembling and adjusting a check valve is provided. A supply passage for supplying operating fluid from a reservoirto a pressure chamberis formed in a cylinder bodyconnected to the reservoir. A bypassfor bypassing the supply passage connecting the reservoirand the pressure chamberis formed and provided with a check valve systemadapted to open when a pressure in the pressure chamberis lower than that in the reservoir. A valve caseand a covering memberconstitute a cartridge, which accommodates a valve bodyand an urging spring, so as to form a check valve system. The cartridgeis placed in a valve chamberof the bypass

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Kanagawa, Japan

Takayuki Kinoshita