Abstract: A memory device, includes a non-volatile semiconductor memory including a plurality of first areas, each corresponding to an erasing unit, each of the first areas including a plurality of second areas, each corresponding to a writing unit; and a controller circuitry configured to erase data stored in a first area of the non-volatile semiconductor memory, track amount of time elapsed since the erasing data from the first area, write first data into one or more unwritten second areas of the first area before the tracked amount of time reaches a particular time period, and write second data into one or more unwritten second areas of the first area in response to the tracked amount of time reaching the particular time period, each of the writing of the first data and the writing of the second data being carried out independently of an instruction from a host.

Abstract: A memory device, includes a non-volatile semiconductor memory including a plurality of first areas, each corresponding to an erasing unit, each of the first areas including a plurality of second areas, each corresponding to a writing unit; and a controller circuitry configured to erase data stored in a first area of the non-volatile semiconductor memory, track amount of time elapsed since the erasing data from the first area, write first data into one or more unwritten second areas of the first area before the tracked amount of time reaches a particular time period, and write second data into one or more unwritten second areas of the first area in response to the tracked amount of time reaching the particular time period, each of the writing of the first data and the writing of the second data being carried out independently of an instruction from a host.

Abstract: A memory device includes a non-volatile semiconductor memory including a plurality of first areas, each corresponding to an erasing unit, each of the first areas including a plurality of second areas, each corresponding to a writing unit and a controller configured to erase data stored in a first area of the non-volatile semiconductor memory, track amount of time elapsed since the erasure of data from the first area, and write data into one or more unwritten second areas of the first area in accordance with the elapsed time, independent of a command to write data into the unwritten second areas.

Abstract: A memory device includes a non-volatile semiconductor memory including a plurality of first areas, each corresponding to an erasing unit, each of the first areas including a plurality of second areas, each corresponding to a writing unit and a controller configured to erase data stored in a first area of the non-volatile semiconductor memory, track amount of time elapsed since the erasure of data from the first area, and write data into one or more unwritten second areas of the first area in accordance with the elapsed time, independent of a command to write data into the unwritten second areas.

Abstract: A memory device includes a nonvolatile memory unit including a plurality of blocks, and a memory controller. The memory controller is configured to determine target blocks for garbage collection, and transfer valid data in the target blocks to another block during the garbage collection. The target blocks includes a first block that has a valid data ratio greater than zero and equal to or smaller than a predetermined value and a second block that has a valid data ratio greater than the predetermined value.

Abstract: A head slider includes a base surface extending in a first direction and a second direction orthogonal to the first direction, a pair of side pads that are spaced apart from each other in the second direction on the base surface and have air bearing faces of a predetermined height from the base surface, a pair of rib portions that extend from the side pads to an end of the base surface in the first direction and have faces of a height between the base surface and the air bearing faces, and a joint portion that connects opposing ends of the pair of rib portions in the first direction and has a face of a height between the base surface and the air bearing faces.

Abstract: A magnetic disk apparatus includes a magnetic recording medium that records information, a magnetic head slider flying over a surface of the magnetic recording medium to read or write information from or to the magnetic recording medium, a rear rail having a rear ABS and a rear stepped bearing surface on an air outflow side from which air flows out from the magnetic head slider, the rear stepped bearing surface being deeper than the rear ABS, and at least one closed vibration attenuation groove that is formed on the rear ABS of the rear rail with a depth greater than the rear ABS and has the rear stepped bearing surface on an air inflow side.

Abstract: A disk device comprises a disk having predetermined information sectors recorded at a constant interval; a head scanning the disk; and a disturbance-compensation unit obtaining an amount of a disturbance based on a time-interval measurement in reading the predetermined information sectors so as to compensate a position of the head according to the amount of the disturbance.

Abstract: A disk drive unit includes acceleration sensors mounted thereon. A sequence for calculating an amount by which a head actuator is adjusted during recording and readout operations is changed based on an output from the acceleration sensors.

Abstract: A magnetic disk unit has two actuators each rotating on a common rotary shaft. The two actuators are driven by a voice coil motor. The voice coil motor comprises: a magnetic circuit comprising a magnet provided for the two actuators on a common basis and two yokes, which are associated with the two actuators, respectively, said two yokes being disposed at both sides between which the magnet intervenes; and two coils provided for the two actuators, respectively.

Abstract: A small-sized rotational vibration testing apparatus having a wide band of measuring frequencies and capable of directly driving a rotary table (1) to oscillate or vibrate in a rotational direction under the action of torque generated by a vibration applying mechanism. The rotary table (1) is rotatably mounted on a base (2), and a plurality of coil frames (14) each having a coil (13) attached thereto are mounted on a flange (1c) of the rotary table (1) at an equal circumferential pitch or interval about its axis of rotation. A plurality of magnetic circuits (12) are fixedly secured to the base (2) in such a manner that the center of each coil (13) is positioned at the center of an associated magnetic circuit (12).

Abstract: A disk drive unit mounts an acceleration sensor. A sequence for calculating an amount by which a head actuator is adjusted during recording and readout operations is changed based on an output from the acceleration sensor.

Abstract: A disk device comprises a disk having predetermined information sectors recorded at a constant interval; a head scanning the disk; and a disturbance-compensation unit obtaining an amount of a disturbance based on a time-interval measurement in reading the predetermined information sectors so as to compensate a position of the head according to the amount of the disturbance.

Abstract: Disclosed is a calibration method for an acceleration sensor in a storage device for calibrating and a storage device, an enclosure for calibrating the acceleration sensor for compensating a vibration of an enclosure in a state of its being mounted in a storage drive. The calibration method and mode comprises a step of exciting a actuator of the drive by flowing a drive current having a predetermined current value, a step of calculating the acceleration of the enclosure of the drive from the predetermined current value and a mechanical transfer function of the storage device, a step of detecting a measured value of the acceleration sensor, and a step of calculating a sensitivity of the acceleration sensor from the calculated acceleration and from the detected measured value. The acceleration sensor is calibrated in the state of its being mounted in the disk drive, and hence the sensitivity can be precisely calibrated.