Abstract: A method is provided for identifying an equalization target for a channel. The method includes measuring a goodness metric for first and second candidate equalization targets and selecting the candidate equalization target with the best measure of the goodness metric as the equalization target for the channel.

Abstract: A disk storage apparatus including a position detection section for producing position error information corresponding to the current position of a head from servo information which has been previously recorded on a disk and is detected by the head, a position control section for producing position control information corresponding to the position error information, a voltage detection section for detecting a voltage generated in driving an actuator for positioning the head with respect to the disk, and for outputting a voltage signal, a disturbance estimation section for estimating the magnitude of a disturbance exerted on the head from the voltage signal by the voltage detection section and from a drive signal by a drive section of the actuator, and producing disturbance estimation information, a correction section for correcting the position control information by the position control section with the disturbance estimation information and producing the drive signal, and a disturbance monitor section for m

Abstract: Detecting flaws in a disk drive includes sampling a read signal provided by reading a data pattern from a disk to obtain samples, obtaining significant samples from the samples, deriving a value from the significant samples, and reporting a flaw if a comparison between the derived value and a threshold value is unacceptable.

Abstract: A magnetic recording medium and a method of manufacturing the same which serve for stable head behavior and efficient recording of servo information. In each servo area, a magnetic layer is separated into a plurality of servo pattern unit parts for forming a predetermined servo pattern and a plurality of servo pattern gap filling parts patterned to fill gaps between the plurality of servo pattern unit parts partly. The servo pattern unit parts and the servo pattern gap filling parts are formed in different sizes so as to have different magnetic properties.

Abstract: A magnetic recording medium is made of a thin film medium that includes magnetic grains. At least one of a magnetization density of the magnetic grains, a crystalline anisotropy field of the magnetic grains, a thickness of the recording medium, an average diameter of the magnetic grains, and a surface packing fraction of the recording medium are selected so that resulting magneto-static fields both decrease thermal switching of individual magnetic grains and enhance collective switching of a group of magnetic grains in response to a switching magnetic field.

Abstract: In a magnetic recording system applied to a magnetic recording medium having a magnetic layer composed of a metal magnetic thin film, the error rate of the magnetic recording medium can be reduced by selecting an isolated reproducing waveform half-width less than the shortest recording wavelength to be used.

Abstract: A portable information processing apparatus in provided with a magnetic disk device switchable to a state providing increased resistance to physical shock upon prediction that such a shock is likely. Under predetermined conditions, a second prediction may be issued that such a shock is no longer likely, allowing the magnetic disk device to switch to a normal state of operations. The shock-resistant state of the magnetic disk device can prevent data access and thus inhibit the progress of important process(es). Upon recognition that an important process is being delayed, the condition for issuing the second prediction may be relaxed to more quickly return the magnetic disk device to a normal operating state.

Abstract: The present invention comprises an implementation of a variable data TPI hard drive system. In one embodiment, the system is implemented by configuring a group of servo tracks in a radial direction for a hard drive media. The group is comprised of an integral number of servo tracks that is constant throughout the drive device. The number of data tracks in a group is also an integer but will vary for each surface according to the head used for R/W operations for each media surface. Group boundaries coincide with media surface R/W zone boundaries. The groups are accessed in hard drives having multiple surfaces in a serpentine manner. Data tracks per group are reduced from what is achievable to produce desired target capacities.

Abstract: A method of determining and monitoring head polarity of data heads comprises performing a head polarity detection routine. The head polarity detection routine comprises the step of setting a read gate period duration to a first value. The routine also comprises searching for a good address mark signal during a first read gate period with a channel polarity set to a first polarity. The routine further comprises identifying a polarity of a data head based upon the channel polarity when the good address mark is detected.

Abstract: Servo tracks for magnetic tape storage are written using two opposite polarities, rather than the one polarity normally used in servo tracks. Timing continues to be performed using only pattern members of like polarity, due to physical restraints, but the use of two polarities allows additional information to be encoded in the pattern more efficiently.

Abstract: A data read channel for receiving a signal containing a data stream of different types of data and recovering data therefrom, the channel comprising a main data read channel operable to output a stream of recovered data and a branch from the main data read channel comprising a signal analyser to determine the type of data from the data stream of different data types flowing in the main data read channel and a controller operable to control at least one element of the main data read channel in response to the type of data identified by the signal analyser from the data stream.

Abstract: High rate writing of data recorded on a CD into a hard disk drive (HDD) is performed while reproducing data read out of the CD at the standard bit rate prescribed for the CD. PCM data corresponding to a playback time of 10 seconds, for example, is read out of a CD and stored in a memory for subsequent read out. In parallel, data for writing is read out of the CD and stored in the memory. The data read out of the memory is coded and compressed by an encoder and then stored back in the memory. When the data stored in the memory for playback has become smaller than a predetermined amount, an interrupt is generated during the writing process with the processing, which is given top priority, so that a next set of playback data is read out of the CD and stored in the memory.

Abstract: The present invention comprises an implementation of a variable data TPI hard drive system. In one embodiment, the system is implemented by configuring a group of servo tracks in a radial direction for a hard drive media. The group is comprised of an integral number of servo tracks that is constant throughout the drive device. The number of data tracks in a group is also an integer but will vary for each surface according to the head used for R/W operations for each media surface. Group boundaries coincide with media surface R/W zone boundaries. The groups are accessed in hard drives having multiple surfaces in a serpentine manner. Data tracks per group are reduced from what is achievable to produce desired target capacities.

Abstract: A disk drive is disclosed comprising a disk surface having a plurality of concentric, radially spaced tracks, wherein each track comprises a plurality of data sectors and a plurality of servo sectors. At least two different index marks are distributed around the circumference of the disk surface. A servo sector counter is initialized relative to which index mark is detected, wherein the servo sector counter identifies a circumferential location of the servo sectors.

Abstract: Upon data recording, a data recording unit inserts revise bytes as a predetermined specific code train into at least two or more portions including the head and last portions of data and records the data onto a medium. Upon data reproduction, a data reproducing unit separates a head reproduced signal by using clocks and, thereafter, executes a clock extraction and an amplitude correction by using a signal corresponding to the revise bytes as a specific code train. In principle, an RLL code for the clock extraction and gain tracking is eliminated and, in place of the RLL code, the revise bytes comprising the specific code train are inserted into the data and the data is recorded onto the medium.

Abstract: Encoded data read by the various and upgraded encoding methods can be decode easily and inexpensively. A tape reading unit 1 is provided to read encoded A/V data and program data from a magnetic tape. A program data extractor 5 is provided to extract the program data from the data read from the magnetic tape. A controller 4 is provided to install the program data to a DSP 3. The DSP decodes the encoded A/V data based on the program data.

Abstract: A master information carrier for magnetic transfer to an in-plane magnetic recording medium includes a base sheet having an irregularity pattern representing information to be transferred to an in-plane magnetic recording medium and a magnetic layer formed along the irregularity pattern. The thickness da1 of the magnetic layer on the upper surface of a protruding portion of the irregularity pattern and the thickness da2 of the magnetic layer on each of the side surfaces of the protruding portion satisfy the following condition, 0.05<da2/da1?1.3.

Abstract: A write driver output circuit having a programmable output impedance. A plurality of amplifiers are disposed in parallel between an input and an output of an impedance matching section of the write driver circuit and can be selectively enabled to correspondingly set the output impedance of the write driver circuit. The amplifiers may be Class AB amplifiers, each of which have a smaller size than an conventional AB used in a single amplifier write driver circuit. Each of the Class AB amplifiers has a corresponding matching resistor, and a current source, each being selectively enabled and disabled by enabling and disabling, respectively, the corresponding current sources, such as through the use of serial interface bits.

Abstract: An amplifier (70) has a differential input stage (84,86). An output transistor (102) is connected to receive a single ended output developed by transistor 86. First (74) and second (76) current sources are connected to establish respective first and second currents in the input differential transistors (84,86) according to a predetermined ratio. First and second voltages are subtracted from the differential inputs (VM,VP) in respective differential amplifiers (88,90), and the output is derived from the output transistor having a magnitude proportional to an inverse of a product of a square of the reference resistance, a carrier mobility, and an oxide capacitance.

Abstract: For use with a servowriter that includes a writer core having a plurality of transistors that route servowriting current in response to a servo write signal, a write transition controller, a method of operating the same and a magnetic disk drive incorporating the controller or the method. In one embodiment, the controller includes: (1) logic circuitry, coupled to the writer core, that selectively blocks the servo write signal based on a state of a write current control signal and (2) current shunt circuitry, coupled to the writer core, that operates concurrently with the logic circuitry selectively to shunt current around the writer core based on the state.