Abstract: According to one embodiment, a control device includes a writer, a setting module, a reader, and an Iw sensitivity acquiring module. The writer writes a signal by the magnetic head. The setting module sets an electric parameter to the magnetic head. The reader reads the signal by the magnetic head. The Iw sensitivity acquiring module acquires Iw sensitivity of the magnetic head. The Iw sensitivity acquiring module includes a first acquiring module, a second acquiring module, and an Iw sensitivity calculator. The first acquiring module acquires a predetermined output value related to control of a signal having a predetermined frequency. The second acquiring module acquires a predetermined output value related to control of the signal having the predetermined frequency. The Iw sensitivity calculator calculates the Iw sensitivity of the magnetic head based on the predetermined output values acquired by the first and second acquiring modules.

Abstract: According to one embodiment, a head slider, includes: a slider main body; an insulating nonmagnetic film laminated on an end surface of the slider main body at an air outflow side; a head element embedded in the nonmagnetic film; a heater embedded in the nonmagnetic film in association with the head element; a conductive terminal formed on an end surface of the nonmagnetic film at the air outflow side; a conductive pattern configured to electrically connect the heater and the conductive terminal with each other; and a radiator configured to contact the conductive pattern and dissipate heat transmitted from the conductive pattern.

Abstract: According to one embodiment, a magnetic disk of a patterned media type, has a plurality of zones divided in radial direction on a magnetic recording surface. A plurality of segments which are included in each of the zones includes a data recording area composed of data recording unit of magnetic material and a first resync area in which a reference signal pattern for setting the timing of writing data in the data recording area has been recorded. The number of segments included in each of the zones is an integer and has a common divisor.

Abstract: According to one embodiment, a magnetic disk device includes a magnetic disk, a slider opposed to the magnetic disk, and a magnetic head on the slider. The magnetic head includes a head element configured to carry out recording or reproduction, a heating element configured to thermally protrude the element, and a groove configured to partition a peripheral area of the head element in a direction in which the head element are to protrude.

Abstract: According to one embodiment, a touch-down determining device, includes: an alternating current perturbation module configured to periodically perturb power of a heater by an alternating current, the heater adjusting protrusion amounts of a write magnetic pole and a read element of a magnetic head in a direction towards a recording medium; a change detector configured to detect a change in a spectrum level of a portion of a spectrum of a read signal read from the recording medium by the magnetic head receiving the power perturbed by the alternating current, the portion of the spectrum corresponding to the alternating current; and a touch-down determining module configured to determine whether touch-down is made, based on the change in the spectrum level detected by the change detector.

Abstract: A signal processing circuit performs processing for an analog signal output from a head. The signal processing circuit includes: a conversion section that generates a digital signal based on the analog signal; a first filter that equalizes the output of the conversion section; a demodulation section that demodulates data from the output of the first filter; a modulation section that modulates a waveform based on the data demodulated by the demodulation section; a second filter that equalizes the output of the modulation section; and an adaptation section that adapts the response of the second filter such that the output of the second filter becomes equal to the output of the conversion section.

Abstract: According to one embodiment, a magnetic storage medium, includes a magnetic recording layer that includes: a servo area including predetermined servo information; a user data area including predetermined user information; two preamble areas including a plurality of magnetic bodies made of magnetic particles, the magnetic bodies being arranged in a staggered pattern so that the staggered pattern is inverted with respect to an axis of symmetry at a track center; and a re-sync mark area positioned at a head of the preamble areas and indicates a start of the preamble areas.

Abstract: According to one embodiment, a slider support mechanism includes a flexure includes a distal end portion on a front side mounted with a slider includes a magnetic head configured to record/reproduce data on/from a recording medium, a hinge plate configured to produce spring force urging the slider toward the recording medium, a load beam joined to a front portion of the hinge plate, and a base plate joined to a rear portion of the hinge plate. The flexure comprises a front portion on a back side joined to the load beam, a rear portion on the back side joined to at least one of the rear portion of the hinge plate and the base plate, and a control mechanism configured to control the spring force.

Abstract: It is related to a head control method. The head control method controls a protruding flying height of a head in which an energization amount applied to a heater element in the head to thermally expands the head. The head control method includes a resistance-value measuring step of measuring a resistance value of the storage element, an energization-amount calculating step of calculating an energization amount applied to the heater element such that the resistance value measured in the resistance-value measuring step reaches a reference resistance value, and a heater control step of performing control to apply the energization amount calculated in the energization-amount calculating step to the heater element.

Abstract: A master-disk producing device produces a master disk with master-disk identification information added. A disk producing device produces a first disk with the master-disk identification information added, using the master disk with the master-disk identification information added. A first disk device obtains, after the first disk with the master-disk identification information added is mounted, first correction information from a correction-information storing device based on the master-disk identification information of the first disk.

Abstract: According to one embodiment, a storage device includes: a control circuit configured to perform a write retry when data writing fails, wherein the control circuit recognizes that read commands are issued at regular intervals for reproducing continuous pieces of data, and upon detecting an error requiring the write retry to be performed in the data writing by a write command received during the reproduction, the control circuit interrupts the data writing, perform data reading to store the data in the buffer memory after allocating a storage area for the data in the buffer memory, and then resumes the data writing.

Abstract: According to one embodiment, a write detector detects a predetermined state where a flash memory contains an area to which write data subject to a write request from a host is to be written and from which data has been erased. A data reception controller allows a data buffer to receive the requested write data in accordance with the detection of the predetermined state.

Abstract: According to one embodiment, a recording medium drive includes a housing, a recording medium, a head actuator member stored in the housing reciprocatably about a shaft, and facing the recording medium at one end, a load tab on the end of the head actuator member, a ramp member fixed in the housing at an outer side of the recording medium, and defining a sliding surface that receives sliding of the load tab, a heater increasing a temperature of the ramp member based on a supplied driving current, a temperature sensor detecting a temperature inside the housing and outputting temperature information, a memory storing profiles of the driving current each set for a predetermined temperature range, and a control circuit supplying a predetermined value of driving current to the heater based on one of the profiles corresponding to the temperature information.

Abstract: A magnetic disk device testing method includes obtaining index values indicating the signal quality of an adjacent track at different positions scattered in the width direction in the adjacent track located in the vicinity of a target track on a magnetic disk after repeatedly writing data onto the target track, and determining a representative value of the index values indicating the signal quality of the adjacent track based on the obtained results, while incrementing the number of data write times; and estimating an index value indicating the signal quality of the adjacent track to be obtained where data is written onto the target track a larger number of times than the total number of data write times the data has been actually written in obtaining the index values, the index value being estimated with the use of the representative values decided in the representative value deciding.

Abstract: According to one embodiment, a storage device includes a spindle assembly including a spindle motor configured to rotate a disk, and a clamp ring configured to fix the disk to the spindle motor, and a slider with a head configured to read/write data on/from the disk, and configured to fly over a surface of the rotating disk. The slider includes a trailing edge on a floating surface of the slider opposed to the disk, and the trailing edge is an end part through which an airflow exits. The spindle assembly and the slider are configured to satisfy a relationship of 0.95f?F?1.05f at a temperature of 23° C., where f is an anti-resonance frequency of the trailing edge, and F is a resonance frequency of the spindle assembly.

Abstract: According to one embodiment, an encryption device uses N extended keys (N: a natural number not less than 2) obtained by extending one encryption key, and includes a first memory, a comparison circuit, a second memory, a selector, and an extension calculator. The first memory stores a flag corresponding to an initial value of a key. The comparison circuit outputs a signal indicating comparison matching when a command and the key are related to encryption. The selector loads the key in the first memory into the second memory upon receiving the signal. The extension calculator calculates the extended keys based on the key in the second memory and inputs them to the selector. Except when loading the initial value of the key into the second memory, the selector loads the extended keys into the second memory to extend the encryption key to from the first to N-th extended keys.

Abstract: According to one embodiment, a medium recording device includes a reading/writing module configured to read/write data from/to a recording medium, a buffer memory configured to temporarily store the read data and data from a host, and a controlling circuit configured to, in response to a read command, read data from the buffer memory or the recording medium to transfer the data to the host, and in response to a write command, to store data from the host in the buffer memory, to write the data onto the recording medium, and to execute a write retry when writing fails. The controller circuit recognizes a read command issued by the host at a fixed interval for replaying continuous data, and determines whether write in response to a write command received during the replaying is likely to fail, and when the write is likely to fail, permits a reception of the read command issued at the fixed interval.

Abstract: According to one embodiment, an arbiter transmits its own arbitration signal from a port to a fibre channel loop in order to acquire a possessory right for the fibre channel loop when a data transmission request has occurred at the port. A detector detects a latency time from when its own arbitration signal is transmitted until the possessory right is acquired. A frame transmitter transmits a frame with a burst length corresponding to the detected latency time from the port to a destination via the fibre channel loop.

Abstract: According to one embodiment, a voltage measuring device that measures an input voltage signal includes a divider, a filter, an adder, and an analog-to-digital converter. The divider divides the input voltage signal into a first signal and a second signal. The filter filters the first signal and attenuates a direct current component of the first signal less than a predetermined frequency component of an alternating current component of the first signal. The adder adds an output signal of the filter to the second signal. The analog-to-digital converter converts an output signal of the adder into a digital signal. The divider adjusts the amplitude of at least one of the first signal and the second signal such that the level of a direct current component of the output signal of the adder is in the input range of the analog-to-digital converter.

Abstract: A carriage for a disc device, which has a top arm, bottom arm, and mid arm, has a main mode, end arm mode, and mid arm mode as a frequency response obtained when subjected to a vertical shake. In the main mode, all of the top, bottom, and mid arms swing at a first frequency within the same phase in a primary bending mode. In an end arm mode, the top and bottom arms swing at a second frequency higher than the first frequency within opposite phases and with an amplitude larger than that of the mid arm. In the mid arm mode, the mid arm swings at a third frequency having a difference of 50 Hz or less from the second frequency within the same phase as in the main mode, and the top and bottom arms swing within the phase opposite from that in the main mode.