Abstract: A head position control method controls the position of a head by correcting components synchronizing rotation of a disk based on the head control amount. A correction signal for components synchronizing rotation is generated by using a filter function. The filter function that integrates the sine and cosine terms of DFT and inverse DFT and forms multiply of the complex values a(m) and b(m) and sine and cosine for frequency conversion, is measured in advance. The complex values are the m degree of RRO frequencies having frequency characteristics to be multiplied (1+C(z)P(z)) or ?(1+C(z)P(z)/P(z)).

Abstract: According to an aspect of an embodiment, a storage apparatus has a storage for storing a plurality of compensation values in association with a plurality of bit sequence patterns, a head for writing data into a medium and a controller for controlling the apparatus and driving the head, the controller determining whether to use one of the compensation values to drive the head to write an instantaneous data bit in dependence upon the immediate preceding data bits in reference to the bit sequence patterns.

Abstract: A head IC adjusts an amplitude level of a read signal of a head to adjust dispersion of the output characteristic of the head and to adjust the read signal within the input dynamic range of the AGC of a read channel. An AGC amplifier is installed in a head IC connected to a read channel and a feedback response speed of an AGC circuit of the head IC is set to be sufficiently slower than a feedback response speed of an AGC circuit of the read channel. Also a peak hold circuit and an amplitude limiting circuit are installed in the head IC, and gain is adjusted with a holding value of the peak hold circuit. An initial gain can therefore be stably adjusted at high-speed without being influenced by signals having a small amplitude on the medium.

Abstract: In a position control device having a disturbance suppression function, loop gain is calibrated without stopping disturbance suppression control. The position control device has, for disturbance suppression control, a feedback controller for changing the loop characteristic, a table for storing a target gain according to a disturbance frequency, and a gain calibration section for calibrating open loop gain. The gain is calibrated using a target gain in the table according to the change of the loop characteristic of the feedback controller. Open loop gain can be calibrated without interrupting the disturbance suppression control, so the open loop gain can be accurately calibrated without being affected by disturbance, and accurate position control is possible.

Abstract: According to an embodiment, a magnetic storage medium includes a data area in and from which a magnetic head on a magnetic head slider records and reproduces data, the data area including an innermost peripheral radius Rid [m] and an outermost peripheral radius Rod [m]. If a rotational speed during recording and reproduction of the data is RPS [rps], waviness of the storage medium with a wavelength in a range between ?1 (=2×?×Rid×RPS/300,000) and ?2 (=2×?×Rod×RPS/100,000) is set to at most 0.05 nm in terms of a standard deviation value (sigma value).

Abstract: According to one embodiment, a storage device includes a clamp ring on a disc, configured to fix the disc to a spindle motor configured to rotate the disc, and a screw configured to fix the clamp ring to the spindle motor, and includes a screw-head and a recess in the screw-head, a center of the recess being decentered from a center of the screw-head.

Abstract: According to one embodiment, a magnetic recording head includes a flying surface and an exposed surface exposed on the flying surface. The exposed surface is defined by oblique sides and a lower side of a trapezoid having an upper side on the trailing side, and a contour line. The lower side on the leading side extends in parallel to the upper side and is shorter than the upper side. The contour line extends from one end to the other end of the upper side and rises from the upper side towards the trailing side between extended lines of the oblique sides.

Abstract: Firmware FW1 and FW2 is separately stored in a non-volatile memory, in which a boot code for start-up and a restoration code are stored, and a first magnetic disk. A copy of the firmware FW1 stored in the non-volatile memory is stored in the first magnetic disk, and a copy of the entire firmware FW1 and FW2 stored in the first disk medium is stored in the second magnetic disk. When an error occurs during firmware update, upon next power-on, whether the volatile memory, the first magnetic disk, and the second magnetic disk are normal or abnormal is determined, and valid firmware is read and allocated to the volatile memory so as to perform start-up by a start-up mode corresponding to the determination contents.

Abstract: A head flying height control method includes the steps of: detecting contact of a head having a heater with a corresponding storage medium, and associating the amount of heat generated by the heater when the contact is detected with a situation where the flying height of the head is zero; measuring at least one type of characteristics that are the saturation characteristics of the read margin of data written on the storage medium with the head, and the saturation characteristics of the electromagnetic conversion characteristics of the head, the measuring step being carried out every time the flying height of the head is varied, with a reference being the situation where the flying height of the head is zero, the current used for writing the data being a parameter in the saturation characteristics; and adjusting the flying height of the head, based on the measurement result of the measuring step.

Abstract: A storage device includes a storage medium, a nonvolatile memory, a head, a driving unit, and a processor. The driving unit drives the storage medium. The processor controls the storage device according to a process. The process includes receiving the data transmitted from the host, storing the data received into the nonvolatile memory, estimating a period of time from a time point of the reception of the data to a time point at which a usage rate of the nonvolatile memory becomes 100%, controlling the driving unit on the basis of comparison of the estimated period of time with a period of time before the storage medium is accessible, and writing the data stored in the nonvolatile memory to the storage medium by controlling the head in accordance with the control of the driving unit.

Abstract: A device interface circuit unit transfers a command and data in packet format between the unit and the host. A transport layer is provided with a receive FIFO, a command detection circuit and a send FIFO, and an application layer is provided with a receive task file register and a send task control file register. An available time is generated for each break point of a packet during data transfer in order to receive another command packet from the host. When the command packet is received from the host in the available time during data transfer, the data transfer is suspended and the received command is decoded to execute a process for continuing or canceling the data transfer, after which the data transfer is resumed.

Abstract: According to one embodiment, there is provided a head flying height control method for controlling a flying height of a magnetic head from a magnetic storage medium. The magnetic head includes an element portion and a heater that effects a change in a protrusion amount of the element portion due to thermal expansion accompanying heat generation. The head flying height control method includes: causing the element portion to protrude a maximum protrusion amount by increasing a heater power of the heater; first-reducing the heater power based on a relation between the protrusion amount and the heater power until the protrusion amount becomes a predetermined protrusion amount; and second-reducing, if a head-medium property is better than a target value after the first-reducing, the heater power based on a relation between the head-medium property and the heater power so that the head-medium property matches the target value.

Abstract: According to one embodiment, a storage device includes a recording medium, a head slider, a head suspension, an actuator, and an alternating current component generator. The head slider faces a surface of the recording medium. The head suspension supports the head slider. The actuator is incorporated in the head slider and increases the protruding length of a protrusion formed on the head slider toward the surface of the recording medium based on an increase in a supplied electrical signal. The alternating current component generator superimposes an alternating current component having a frequency equal to the natural frequency of the head suspension over the electrical signal while increasing or decreasing the protruding length of the protrusion at a predetermined amplitude.

Abstract: According to one embodiment, an information processing system includes a plurality of information processing devices connected to one another and capable of transmitting/receiving data to/from one another. One information processing device includes a determiner configured to determine whether an address level included in a transmission signal transmitted from another information processing device is for specifying the one information processing device based on information on the address level, and a data receiver configured to receive real data included in the received transmission signal when the determiner determines that the address level is for specifying the one information processing device.

Abstract: Data in a storage medium is scanned while a storage device is in an idle state. A proportion of scanned data in entire data in the storage medium is compared with a threshold value. If the proportion of the scanned data is less than the threshold value, an unscanned data in the storage medium is scanned during a time interval between commands received by the storage device from outside. The process is repeated until the proportion of the scanned data is equal to or more than the threshold value.

Abstract: A storage apparatus including a motor for rotating a medium and a head that has a heater. The clearance between the medium and the head is controlled by expansion of the head by the heater. Some embodiments could include a monitor configured to monitor atmospheric pressure, and a controller configured to control the heater in accordance with the atmospheric pressure so as to control the clearance. Some embodiments could include a monitor configured to monitor a driving current flowing through the motor, and a controller configured to control the heater in accordance with the driving current so as to control the clearance.

Abstract: According to one embodiment, a head slider includes an element unit formed by lamination on a substrate, a cut surface formed by cutting the substrate, an air-bearing surface configured to face a recording medium when in flight, a protective layer configured to protect at least the air-bearing surface of the element unit, and a coating layer configured to cover at least the cut surface exclusive of the air-bearing surface of the element unit. An outermost surface of the air-bearing surface is formed of the protective layer in the element unit at the least.

Abstract: According to one embodiment, a piezoelectric element is provided by forming a first electrode film on a major surface of a substrate, forming a modified film by modifying at least a portion of the major surface of the substrate by heating the substrate in an ambient containing oxygen, and forming a piezoelectric film by depositing a piezoelectric material on the first electrode film, forming a second electrode film on the piezoelectric film, adhering a support on the second electrode film, and peeling off a multilayered structure including at least the first electrode film, the piezoelectric film, the second electrode film, and the support from the substrate.

Abstract: According to one embodiment, a storage device includes a base, a drive section on the base, configured to rotate a disk storage medium, an actuator mounted with a head for processing data in the storage medium and configured to move the head along a surface of the storage medium, a cover laid over the base, and a plate opposed to the surface of the storage medium in a position outside a range of movement of the actuator. The plate includes a distal end portion located adjacent to the actuator and downstream with respect to a direction of rotation of the storage medium, a block extending from the distal end portion, located outside the outer periphery of the storage medium, and supported on the base side, and an elastically deformable plate arm extending from the block toward the cover and configured to abut an inner surface of the cover.

Abstract: According to one embodiment, a storage device has a head configured to read or write data with respect to a storage medium above the storage medium; a head suspension configured to support the head; a lift tab extending from an end on a head side of the head suspension; and a ramp mechanism configured to hold the lift tab at a retracted position spaced apart from the recording medium. The ramp mechanism has: a rotating shaft; and a disk rotatably supported by the rotating shaft and configured to rotate in a retracting direction by coming into contact with the lift tab that is retracting with the head from above the recording medium, and to guide and retract the lift tab to the retracted position.