International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Hitachi Global Technologies Netherlands B.v.

Yutaka Ozawa

Masashi Kisaka

Kenji Toga

Satoshi Yamamoto

Isao Yoneda

Fuminori Sai

Kenji Ogasawara

Nobuyuki Kitazaki

Hiroshi Yanagisawa

Kohji Takasaki

Kazunari Tsuchimoto

Masahide Yamasaki

An information recording method in a rotating storage apparatus comprising a rotating recording medium for recording information, a head for performing at least a write operation onto the rotating recording medium, and an acceleration sensor for detecting a shock. The method comprises outputting a shock out signal if an output from the acceleration sensor exceeds a predetermined threshold. A signal is output at a first level for a write inhibit period in response to the input of the shock out signal, where the write inhibit period is selected based at least in part on a time span in which the output of the acceleration sensor exceeds the predetermined threshold. Writing to the rotating recording medium is prohibited during the write inhibit period.

Shock resistant, high reliability rotating magnetic storage device and method

Embodiments of the invention efficiently conduct servo corrections for preventing error propagation during SSW. In an example of the present invention, a servo position signal generator generates a servo position signal indicative of the current position of a read element on the basis of a servo signal from a servo channel. A target position generator generates correction data from multiply and add operations between the PES generated when the track that the read element is following is written, and pre-registered correction coefficients. A correction target position is generated from the correction data and a reference target position, and then output to a position error calculator. The position error calculator generates a position error signal (PES) from the servo position signal and the target position signal, and outputs PES to a servo controller. The servo controller generates a control signal (DACOUT) in accordance with PES, and a motor driver unit supplies an electric current of a required value to a VCM in accordance with the control signal.

Method and data storage device for writing patterns onto recording disk

A rotating storage apparatus is provided for high recording reliability in an environment in which a shock or vibration exists. Provided are means for outputting a shock out signal (SO) if an output from an acceleration sensor exceeds a predetermined threshold, a latch circuitfor outputting a latch signal at high level during a predetermined write inhibit period after the shock out signal (SO) is input, and a write gate signal (WG) which goes high when a write is enabled. A write enable signal is generated by an AND circuithaving a NOT output of the latch signal as well as the write gate signal WO as its inputs.

Shock resistant, high reliability rotating magnetic storage device

A method and apparatus for resolving a 'continuity' problem that occurs when modes are switched in the head positioning control process, and a contradiction exists between a short seek and a long seek.

Data storage device, head positioning apparatus and head positioning method

A data storage device that can perform a track following process even when vibrations are produced by a wide range of frequencies.

A rotating storage apparatus is provided for high recording reliability in an environment in which a shock or vibration exists. Provided are means for outputting a shock out signal (SO) if an output from an acceleration sensor exceeds a predetermined threshold, a latch circuit for outputting a latch signal at high level during a predetermined write inhibit period after the shock out signal (SO) is input, and a write gate signal (WG) which goes high when a write is enabled. A write enable signal is generated by an AND circuit having a NOT output of the latch signal as well as the write gate signal WG as its inputs.

A disk drive has a data recording medium such as a disk, a spindle motor for rotating the disk, disk rotation speed controlling logics for supplying a spindle current to the above described spindle motor to rotate the disk at a constant speed, a head unit for accessing the disk, an actuator for moving the head unit, and head position controlling logics for driving the actuator and controlling the position of the head unit. The head position controlling logic obtains the value of the spindle current and controls the position of the head unit on the basis of the above described spindle current value by using the fact that the spindle current varies according to variations in the position of the head unit.

Disk apparatus and head position control method

A method to enable servo information to be detected surely and stably even when a time interval between servo sectors is changed due to disk shifting. A time interval TS(i) is calculated according to an internal variable value, which is in proportion to a displacement &Dgr;r(i) of a servo area SF(i) in a radial direction of a subject disk (step S6). The displacement &Dgr;r(i) is calculated from already detected servo information&lsqb;, thereby&rsqb;. Thereby, a time interval for detecting servo information is adjusted according to the above described time interval TS(i) (steps S7 and S4). The time interval TS(i) is the time interval between passing of a servo sector in the servo area SF(i) under the head H and passing of a servo sector in the servo area SF(i&plus;1) under the head H.

Method for controlling servo information detection timing and rotational speed of disk, and disk drive

A disk drive and a disk drive control method is described which reduces the number of one track seeks a drive performs. The one track seeks can operate the actuator bearing in a non-linear mode or can increase in the friction of the actuator bearing which leads to servo positioning inaccuracies. In the disk drive the logical block address (LBA) assignments are made so that when sequential addresses are allocated to two different tracks, the tracks are physically non-adjacent. Thus, when a sequential LBAs are read across a track boundary, the actuator is moved farther than would be required if the LBAs were assigned the adjacent tracks.

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Fujisawa, Japan

Yutaka Ozawa