Abstract: A magnetic disk device performs test write before storing system information to check the state of each head. The magnetic disk device then stores test write results in a test-write-result table of a RAM. The magnetic disk device then determines whether the number of defective heads is equal to or greater than a predetermined number. When the number of defective heads is equal to or greater than the predetermined number, the magnetic disk device suspends the process of storing the system information. When the number of defective heads is less than the predetermined number, the magnetic disk device refers to the test write results stored in the test-write-result table and performs write only with a head determined as normal.

Abstract: A magnetic disk device performs test write on a test cylinder to check the state of each head before system information is stored in disks. The magnetic disk device then determines the state of each head based on the test write results stored in a test-write-result table. When a head is defective, the magnetic disk device notifies a host of the possibility of the occurrence of a timeout as a fault prediction.

Abstract: A magnetic disk device performs test write to check the state of each of heads before system information is stored in a disk and, based on the result of the test write, stores the system information sequentially with the heads from one in good state. After a predetermined time has elapsed, the magnetic disk device suspends the process of storing the system information.

Abstract: An optical data carrier is presented being configured to provide protection for data recordable therein from environmental effects. The optical data carrier comprises recordable media having an outer surface and an inner data volume in which data is to be recorded, said data volume being spaced from said outer surface a certain minimal distance D, a region of the recordable media surrounding the data volume providing at least optical protection for said data volume.

Abstract: An optical disc apparatus includes an optical pickup for outputting an output signal according to reflected light from an optical disc medium, measures a level of a reflected signal corresponding to reflected light from a medium surface prior to reading of information recorded on the medium, predicts, based on the measured level of the reflected signal, whether or not the reflected signal from the medium surface will satisfy a predetermined detection condition when a focus state is to be detected, and uses a result of the predicting to detect a state where the output signal satisfies the predetermined detection condition as a state where a focus of an objective lens included in the optical pickup is on a signal surface of the medium while relatively moving the objective lens with respect to the medium surface when the information recorded on the medium is to be read therefrom.

Abstract: The characteristics of thin-film magnetic heads are evaluated by measuring, in a step and repeat method and apparatus, the magnetic field generated by the respective heads in a bar including multiple heads.

Abstract: According to an aspect of the embodiment, in a magnetic recording apparatus having a magnetic recording medium of a patterned media system, a voltage generated between both terminals of a magnetic field generating coil in a case that a DC current is supplied to a recording element of a magnetic head is measured by a voltage measuring circuit in order to perform accurate recording at the center of each of magnetic body regions sectioned with non-magnetic body regions. Based on the measured voltage, a change in coil inductance in passage of the magnetic head over a magnetic body region and a non-magnetic body region in a patterned media is detected by a voltage change detecting circuit. A write clock signal which synchronizes with the change in coil inductance is generated by a clock signal generating circuit.

Abstract: A disk operation protection method and a disk controller are disclosed herein. The method includes: receiving a request for a disk operation; obtaining, by a disk controller, operation control parameters corresponding to the current disk area to be operated, and determining whether to allow operation of the current disk area according to the operation control parameters; if determining that the current disk area is allowed to be operated according to the operation control parameters, performing the disk operation. By implementing the embodiments of the present disclosure, the operation of the data stored in a disk is protected, illegal disk operations such as maliciously intended modification are prevented, the disk is protected in the process of generating data, and the defects of the disk protection mechanism in the prior art are overcome.

Abstract: A pattern transfer apparatus includes a storage-medium-surface detecting unit that detects a foreign substance or defect on a surface of a storage medium and specifies a position and a size of the foreign substance or defect; a relative-position adjusting unit that adjusts a relative position on a contact surface between the surface of the storage medium and a transfer pattern surface of a transfer master, and a relative-position-adjustment instructing unit that calculates an adjusted value of the relative position according to a detection result, and instructs the relative-position adjusting unit to adjust the relative position based on the adjusted value.

Abstract: A servo signal recording apparatus of the present invention is provided with a tape motion measurement unit 5 that measures the lateral motion of a magnetic tape 3, and outputs tape motion information, a signal processing unit 20 that generates a servo signal that includes the tape motion information output from the tape motion measurement unit 5, and a servo signal recording head 4 that records the servo signal generated by the signal processing unit 20 to the magnetic tape 3. The tape motion measurement unit 5 measures the tape motion prior to the timing at which a servo signal is recorded to the magnetic tape 3 by the servo signal recording head 4, and records a servo signal that includes the tape motion information. This configuration enables a servo signal that can be used to perform tracking servo at high speed and with high accuracy to be written to a magnetic tape.

Abstract: An optical disk writing apparatus enhances writing accuracy by writing first data (e.g., test data) that encodes a first writing strategy within first patterns on an optical disk, in response to a first writing signal. A reproducing signal is generated in response to reading the first data from the optical disk. Variations between leading and trailing edges of the first writing signal and leading and trailing edges of the reproducing signal are detected. A correction value is determined using a jitter evaluation function to evaluate the detected variations. From these operations, a second writing strategy is determined using the correction value to modify the first writing strategy. Thereafter, second data (e.g., actual data) is written, which encodes the second writing strategy within second patterns on the optical disk.

Abstract: A method for obtaining a refractive index (n) and extinction coefficient (k) map of a slider surface, the method comprising the steps of processing an image of the slider surface to obtain spatially resolved normalized intensity data of the slider surface; measuring n and k values of the slider surface at different areas of the slider surface to obtain reflectivity data of the slider surface; mapping a distribution of the normalized intensity data to a distribution of the reflectivity data for deriving the n and k map of the slider surface.

Abstract: A method of examining a storage disk is proposed. The method repeats steps of: executing a writing operation and a reading operation in sequence to recording tracks at first intervals so as to check a defect in the recording tracks based on the quality of a read signal; and selecting a recording track at a position spaced by a second interval larger than the first interval from a last recording track of the sequence, the recording track being a first recording track of the recording tracks at the first intervals. The method realizes detection of a defect for recording tracks at the first intervals in a concentrated manner. A recording track is then selected at a position spaced by the second interval from the sequence. A defect can reliably be detected without increasing the total number of recording tracks selected as sample tracks.

Abstract: A method and apparatus for controlling flying height for the read/write head of a HDD. The method uses the flying status of the head immediately before the head touches down on the disk to provide such control.

Abstract: A slider tester includes a disk, movable table, table drive mechanism, guide member, etc. A plurality of suspensions are mounted on the movable table. A slider is mounted on each suspension. A guide member can support respective lift tabs of the suspensions. The guide member includes a first guide surface, second guide surface, and opening arranged in a track width direction of the disk. When any of the lift tabs gets into the opening as the movable table moves in the track width direction of the disk, the slider is dropped toward a recording surface of the disk.

Abstract: An apparatus for inspecting a pattern shape of a magnetic record medium or its stamper includes: a moving mechanism, on which an object to be inspected where a pattern is formed is placed and which moves the object to be inspected in a radial direction while rotating the object; an irradiating optical system that applies illuminating light of a wide band including far ultraviolet light to the object to be inspected moved in the radial direction while rotating the object by the moving mechanism in a polarized state suitable for the object to be inspected from an oblique direction; a detecting optical system that detects zero-order reflected light generated from the object to be inspected irradiated by the irradiating optical system; and a shape inspection unit that inspects a pattern shape formed on the object to be inspected based on a spectral reflectance waveform obtained by dispersing the detected zero-order reflected light, thereby inspecting the pattern shape at a high speed and with high sensitivity.

Abstract: An information recording device is provided, which is capable of performing physical reformatting at a high speed while avoiding unnecessary substitution processing after the physical reformatting. A disc recording and reproduction drive 1020 records information on an information recording medium including a volume space for recording user data, a spare area containing a substitute area that can be used instead of a defective area, and a defect management information area for recording defect management information. The defect management information includes defect location information indicating the location of defective areas and defect status information indicating the attributes of the defective area.

Abstract: A defect inspection method and device for a perpendicular magnetic recording medium that has discrete recording tracks and grooves between recording tracks, including DC demagnetizing the perpendicular magnetic recording medium, detecting a reproduced signal from the perpendicular magnetic recording medium after the DC demagnetizing, removing output fluctuation components caused by the grooves from the reproduced signal using a filter with a prescribed cutoff frequency and separating a peak output of the reproduced signal, comparing the peak output with a prescribed reference signal, and identifying a location where the peak output exceeds the reference signal as a defect location.

Abstract: A method for measuring a write width and/or a read width of a composite magnetic head in which a read characteristics profile having a peak as a read voltage characteristics for a moving distance is obtained by writing a test data in a designated track of eccentric tracks of such as a DTM by the composite magnetic head (write head), reading the test data from the designated track by moving the composite magnetic head (read head) in a radial direction and crossing the designated track and a write sensitive width or a read sensitive width is calculated on the basis of the read characteristics profile.

Abstract: In a data storage device, a head writes data so as to protect data from off track writing to adjust tracks. A control unit acquires large ring buffer during sequential writing and performs a retry to return adjacent tracks, according to data of a return sector area of the ring buffer when a write error occurs. A write error due to a detection mistake of an off track error can be prevented.

Abstract: An apparatus includes a controller for enabling replicating of media content from encoded content received, and a recorder responsive to the controller for recording content on media readable by a device other than said recorder.

Abstract: A data storage apparatus includes: a medium for storing data having synchronization marks and data blocks, the synchronization mark and the data block being allocated alternately in the circumference direction of the medium; a head writing data into or reading out data from the medium; and a processor for executing a process including: reading out synchronization marks, measuring time for the head to pass through each of the data blocks based on signals read out from each of the synchronization marks in the circumference direction, generating write/read clock for each of the data blocks, which is continuously changing in speed, by calculating difference in time for the head to pass through the each one of the data blocks and its adjacent one of the blocks on the basis of the time measured, and writing data into or reading out data from the medium in synchronization with the write/read clock.

Abstract: A pattern writing system includes a plurality of control units configured to use different communication standards; a pattern writing unit configured to be controlled by the plurality of control units and write a pattern on a target object by using a charged particle beam; a storage unit configured to receive parameter information from an external slave computer and stores the parameter information; a first interface information circuit group configured to output a received parameter information to at least one of the plurality of control units in conformity with a communication standard on the at least one of plurality of control units; a main computer; and a second interface circuit group configured to receive a request from the main computer, input parameter information been setting in the plurality of control units without passing through the storage unit, convert communication standards of the parameter information input into a communication standard used by the main computer, and output the parameter in

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: A recording/reproducing apparatus is disclosed that includes a spindle motor unit including a spindle on which a flexible recording disk is placed, a stabilizer plate disposed so as to face the recording disk, a torque detection unit configured to detect a drive torque applied to the spindle motor unit, an adjustment unit configured to adjust a gap between the recording disk and the stabilizer plate, and a determination unit configured to determine an optimal gap to be set to the gap based on the drive torque detected by the torque detection unit, in which the adjustment unit sets the optimum gap determined by the determination unit to the gap.

Abstract: The invention provides a magnetic tape device including a magnetic head; a drive unit; an abnormality detector for detecting an abnormality in operation of the magnetic tape; and a release unit for releasing the contact between the magnetic tape and the magnetic head when the abnormality detector detects any abnormality during the running of the magnetic tape.

Abstract: A device for storing data includes: a medium for storing data, the medium having a plurality of areas in a circumferential direction; a head including a read element for reading data from the medium along the circumferential direction, a write element for writing data into the medium along the circumferential direction, and a heater for controlling a distance between the head and the medium; a memory for storing information of a parameter of the heater for controlling the distance between the head and the medium; and a controller for controlling the heater to control the distance between the head and the medium separately among the areas when reading data from or writing data into any one of the areas of the medium.

Abstract: If the amount of information recorded on a user data area of a recording medium is less than a predetermined value when a finalize process is performed on the information recorded in the user data area, dummy information is recorded in the recorded area such that the amount of the information is equal to or greater than the predetermined value, and management information for managing the dummy information as a file is recorded in the user data area, thereby realizing interruption of the finalize process in the recording medium and enabling determination of whether or not a disk is a disk on which a finalize process has been interrupted based on only information recorded on the disk.

Abstract: Embodiments of the present invention precisely measure clearance variation by temperature change using a value in a RW channel. In an embodiment of the present invention, an HDD measures resolution by signals in a RW channel. The measured resolution shows variations depending on temperature according to two factors. One factor is the clearance variation depending on the temperature and the other is the variation in operational property of the RW channel depending on the temperature. The HDD compensates for the temperature variation of the resolution according to the two factors. The HDD uses two kinds of sensed temperature. One corresponds to the temperature inside an enclosure in which head sliders are provided and the other corresponds to the temperature of the chip in which the RW channel is implemented. Sensing the drive temperature and the channel temperature independently achieves precise compensation for the variation in the measured resolution caused by clearance variation and channel property.

Abstract: The method is capable of perfectly detecting unstably magnetized magnetoresistive heads. The method of evaluating a magnetoresistive head comprises the steps of: applying a magnetic field to the magnetoresistive head, in the direction parallel to an air bearing surface of the magnetoresistive head, at a prescribed temperature; obtaining an image of the air bearing surface in a first magnetized state by using the Kerr effect; applying an external stress to the magnetoresistive head; obtaining an image of the air bearing surface in a second magnetized state by using the Kerr effect; and evaluating characteristics of the magnetoresistive head on the basis of the images of the first magnetized state and the second magnetized state or by comparing the images of the first magnetized state and the second magnetized state.

Abstract: A method of detecting a bad servo track of an HDD includes measuring servo AGC of each of servo sectors of a servo track requiring determination of badness, calculating statistic data with respect to the measured servo AGC of each servo sector, and determining whether the servo track is bad based on the calculated statistic data. Since the badness of a servo track is determined based on the statistic data of the servo AGC, a bad servo track generated due to a change in the overall magnitude of a servo signal is easily detected so that reliability in the detection of a detective servo track can be improved.

Abstract: A waveform shaping portion receives a digital reproduced signal generated from an analog reproduced signal reproduced from an information recording medium and shapes the waveform of the digital reproduced signal. A maximum likelihood decoding portion applies maximum likelihood decoding to the digital reproduced signal in the shaped waveform and generates a binarized signal indicating the result of the maximum likelihood decoding. A phase detection portion extracts, during the maximum likelihood decoding, a phase error using state transition patterns having only a single zero cross point among differential metrics at a plurality of merging points at which a set of paths branched from a given state merges. A synchronization detection portion generates a reproduction clock signal using the phase error that has been detected and brings the digital reproduced signal into synchronization with the reproduction clock signal that has been generated.

Abstract: The present invention relates to a method for controlling the quality of storage media, and more specifically to a method for determining if the quality of a storage medium decreases. A method according to the invention has the steps of: determining one or more quality parameters of the storage medium; and comparing one or more of the determined quality parameters with previously determined quality parameters of the storage medium stored in a memory in case the quality of the storage medium has been determined before.

Abstract: A data recording/reproducing method and apparatus which are capable of accurately and stably controlling a gap between a recording medium and a head of the data recording/reproducing apparatus are disclosed. The data recording/reproducing method includes: outputting at least one signal based on a light beam reflected from a recording medium; detecting a minimum value and a maximum value of the output signal; and adjusting a gap between a head of a data recording/reproducing apparatus and the recording medium according to the minimum value and the maximum value.

Abstract: Embodiments include methods, apparatus, and systems for monitoring disk drives to predict failure. One embodiment includes a disk drive having a plurality of different types of sensors that sense events over a lifetime of the disk drive. Data from the events is aggregated to predict when the disk drive will fail.

Abstract: The present invention relates to a magnetic disk substrate, in which an amplitude Wa of a waviness on a surface measured by using an interferometer for a versatile disk at a measuring wave-length of 5.0 mm is within the range of 0.1 nm to 0.5 nm, an average amplitude Wb of a microwaviness generated on the waviness measured by using a microscopy for three-dimensional surface-structural analysis at a measuring wave-length of 30 ?m to 200 ?m is 0.3 nm or less, and a value calculated by dividing the average amplitude Wb of the microwaviness by the amplitude Wa of the waviness is 0.6 or more.

Abstract: A method of operating a hard disk drive (HDD) on the basis of a predicted new defect in a disk associated with the HDD is disclosed. The method includes detecting defects in a magnetic surface of the disk, defining a plurality of clusters by grouping the detected defects using a hierarchical clustering algorithm, calculating a curve fit for each one of the plurality of clusters, predicting a new defect likely to occur in the magnetic surface of the disk on the basis of the calculated curve fit; and writing data to the disk on the basis of the new defect prediction.

Abstract: A data storage and retrieval system that comprises a data storage device is disclosed. The data storage and retrieval system further comprises a first LED, a second LED, a third LED, and a fourth LED, interconnected with the data storage device. The data storage device causes the first LED and the second LED to emit first light comprising a first color if the data storage device detects an internal failure. Alternatively, the storage device causes the third LED and the fourth LED to emit second light comprising a second color if the data storage device remains operative.

Abstract: The generation of a pseudo-lock is prevented in a JFB offset compensator whose use has been conventionally limited due to a tendency to generate the pseudo-lock, and performance degradation of a PLL and a Viterbi decoder is suppressed. A means for monitoring an offset of a read signal is provided independently from the JFB offset compensator. With this configuration, the generation or a possibility of the generation of the pseudo-lock can be detected to reset an integrator. In order to reduce the influence of a large sporadic offset triggering the pseudo-lock, there may also be provided a limitter for limiting the absolute value of an offset signal inputted to the integrator or a limitter for limiting the absolute value of an offset compensation signal.

Abstract: An optical disc apparatus in which a ? method using a ? value showing asymmetry of an amplitude of a reproduction signal or a ? method using a modulation degree of the reproduction signal is executed as an evaluation method of evaluating recording quality of data in an optical disc, wherein: the data recorded by a recording power of a different intensity is reproduced; a ? value and a jitter value are obtained on the basis of the reproduced data, respectively; the ? method is selected as an evaluation method of evaluating the recording quality of the data in the optical disc under such a condition that the obtained ? value satisfies a predetermined requirement for the recording power of the different intensity; and a target ? value is set on the basis of the obtained jitter value when the ? method has been selected.

Abstract: A system and method for measuring the modulation between a magnetic head and a magnetic storage medium, such as a disk, is disclosed. A magnetic read/write head is positioned above a magnetic storage medium at a given flying height. The magnetic read/write head reads a signal from the magnetic storage medium. A tester measures an alternating electric current between the magnetic read/write head through the slider and the magnetic storage medium. A computer may then calculate the modulation by the magnetic read/write head based on the alternating electric current. A DC voltage to the head may be applied to lower the flying height of the magnetic head.

Abstract: The invention is to provide a method for distinguishing optical discs, which first locks a focus on a data layer of an optical disc to cross the grooves and the lands of the optical disc, then starts testing and counting the time for testing, records a detected RF signal, checks if the time for testing reaches a predetermined time, continues locking the focus on the data layer to test if it has not, finds out the maximum intensity of the detected RF signal among the recorded RF signals, and compares the maximum intensity of the detected RF signal with the parameters regarding formats of optical discs previously stored in order to correctly distinguish the optical disc.

Abstract: Embodiments of the present invention help to improve test processes for hard disk drives (HDDs) and increase the manufacturing efficiency of HDDs. According to one embodiment, a test process performs a test on an HDD with respect to a plurality of items and stores one or a plurality of test results. Moreover, it determines the optimum specification category to which the HDD is to belong based on the stored test results. One factor of the specifications—storage capacity—has been determined before the test process or is determined during the test process. The test process classifies HDDs with the same storage capacity into different specification categories, and this classification may be performed in a single test process. This achieves efficient manufacture of HDDs with different specifications corresponding to the diversified usage of HDDs.

Abstract: A record carrier of rewritable type, such as a BD-RE, is operable to perform multiple write operations. Optionally, such a record carrier can nevertheless be treated as a one time recordable record carrier, opening new opportunities for the users, like for example offering a level of protection of user-data therein recorded against unintentional subsequent erasure. The apparatus and method according to the invention enable the logical formatting of the BD-RE disc as a BD Write Once disc.

Abstract: A burst interval measuring apparatus includes: a detector that outputs detection signals that can to measure a burst interval of servo patterns for a tracking servo; and a measuring unit that measures the burst interval based on the detection signals. The detector is constructed so as to be capable of outputting the detection signals that can measure the burst interval at plural positions that are separated in a width direction of the magnetic tape inside one of the servo patterns. The measuring unit uses measurement values for the burst interval at at least two positions out of the plural positions that have been measured based on the detection signals to specify velocity fluctuations in a movement velocity of the magnetic tape in the length direction and corrects the measurement values based on the velocity fluctuations.

Abstract: A waveform equalization control device includes a waveform equalizer that has a filter provided with a plurality of taps, updates the tap coefficient of each of the plurality of taps in accordance with a tap coefficient signal inputted thereto, causes the plurality of taps to respectively receive a plurality of values sampled at different time points from an input signal, performs waveform equalization with respect to the input signal, and outputs the signal after the waveform equalization, an equalization target value generation unit for determining an equalization target value, an error estimation unit for obtaining the error between the equalization target value and the signal after the waveform equalization, and a coefficient update unit for determining an amount of updating the coefficient of each of the taps of the filter of the waveform equalizer based on the error signal and on the input value to each of the taps and outputting the amount of updating the tap coefficient as the tap coefficient signal.

Abstract: There is provided a type judgment device capable of rapidly and safely identifying the type of an optical disc while preventing unexpected information recording or information erase. An optical beam as parallel light is applied in a circular polarized state to an optical disc having recording tracks and the polarization characteristic in the reflected light is detected. According to the detected polarization characteristic, the type of the disc is judged in accordance with the interval of the adjacent recording tracks.

Abstract: Even in the case of copying contents data on a recording medium not compliant with copyright protection, in order to enable the data to be moved to a recording medium compliant with copyright protection, key data to encrypt the contents data is generated per contents data and held in a contents encrypting key memory section 106 in the recording/reproducing device. The contents data is encrypted by the key data in a contents encrypting section 103, while at the same time the key data is encrypted in a key encrypting section 107, both data being recorded together on the HDD 111 not complying with copyright protection. When the contents data is moved to a DVD-RAM 112 of the copyright protection non-compliant recording medium, the key data held in the contents encrypting key memory section 106 is deleted and the contents data cannot be reproduced even by the HDD-DVD recorder 102.

Abstract: A storage media housing device includes a housing means (1) for housing storage media; a position detecting section (2) detecting a position of the housing means (1); a transfer means (3) for transferring the housing means (1) to a desired position on command; a control means (4) for outputting a transfer control signal to the transfer means (3) so as to transfer the housing means (1) to the desired position; a compare means (5) for comparing the desired position of the housing means (1) based on the transfer control signal controlled by the control means (4) and the detected position of the housing means (1) detected by a position detecting means (6); and the position changing means (6) for changing the transfer control signal of the control means (4) based on the compared result of the compare means (5) and for changing the transfer position of the housing means (1).

Abstract: Embodiments of the present invention help to increase the capacity and the reliability of a disk drive device to improve the manufacturing yield thereof. An embodiment of the present invention sets a data track pitch for each head slider (recording surface) in accordance with head characteristics. This method for specifying the data track pitch is based on the distance between erase band ends (EBEs) of the both adjacent data tracks. The erase band of a data track is a band defined as the area where the already written data are erased in writing the data track. The distance between the erase band ends of the both adjacent data tracks corresponds to the width SW of the area which is not erased by the adjacent data tracks. Specifying the data track pitch based on this leads to increase in the data capacity of each recording surface and secure prevention of occurrence of a squeeze error.