Abstract: A magnetic disk device according to one embodiment includes a magnetic disk on which multiple tracks are provided, a magnetic head, and a controller. At least one of the multiple tracks includes first sectors and a second sector. Each of the first sectors stores data segments. The second sector stores a parity for error correction. The magnetic head executes writing/reading to/from the magnetic disk. The controller executes processing of adjusting a guaranteed number of times by using a second sector being invalid. The guaranteed number of times indicates a number of times of writing for guaranteeing reading from an adjacent track.

Abstract: A method according to one embodiment includes reading and/or writing data to a magnetic medium using a head having an array of transducers. An axis of the array is defined between opposite ends thereof, and is tilted at an angle greater than 0° from a line oriented perpendicular to an intended direction of tape travel thereacross during the reading and/or writing. The method further includes at least one of: introducing, by a controller, a timing offset to at least one servo channel to compensate for offset in servo readback signals introduced by the tilt of the head, introducing, by the controller, a timing offset to at least some read channels to compensate for offset in readback signals introduced by a tilt of the head, and introducing, by the controller, a timing offset to at least some write channels to enable writing of transitions that are readable by a non-tilted head.

Abstract: A position detection encoder includes a scale and a detection head and has position detection circuits which are capable of outputting respective pieces of position information on Xf, Xs two tracks. The displacement detection encoder includes: a speed detection circuit which is provided in the detection head and detects a relative speed Xf, Xs relative to the scale; and a delay generation circuit which provides a time difference between two output request signals, the time difference being provided on the basis of a fine adjustment time tadj based on the relative speed Xf, Xs and the respective pieces of position information Xf, Xs on the two tracks, the output request signals St1, St2 urging the first and second position detection circuits to output the pieces of position information on Xf, Xs the two tracks.

Abstract: A disk recording device is disclosed comprising a disk and a head. A first plurality of reference bursts are written along a first radius of the disk, the first plurality of reference bursts comprising a first reference burst. A second plurality of reference bursts are written along a second radius of the disk circumferentially offset from the first radius, the second plurality of reference bursts comprising a second reference burst. A first segment of a reference band is written along a third radius of the disk circumferentially offset from the second radius, and at a first timing offset from the first reference burst. A second timing offset between the first reference burst and the second reference burst is measured, and a second segment of the reference band is written radially coherent with the first segment based on the first timing offset and the second timing offset.

Abstract: A product, according to one embodiment, includes a magnetic recording tape having opposite ends, a longitudinal axis of the magnetic recording tape being defined between the ends. The magnetic recording tape has at least one servo track, the at least one servo track having a plurality of first magnetic bars and a plurality of third magnetic bars oriented to form chevron-like patterns with the first magnetic bars. The first magnetic bars each have a longitudinal axis oriented at a first angle between 2 and 88 degrees from the longitudinal axis of the magnetic recording tape. The third magnetic bars each have a longitudinal axis oriented at a second angle between 2 and 88 degrees from the longitudinal axis of the magnetic recording tape, the second angle having a different numerical absolute value than the first angle.

Abstract: A position detection encoder includes a scale and a detection head and has position detection circuits which are capable of outputting respective pieces of position information on Xf, Xs two tracks. The displacement detection encoder includes: a speed detection circuit which is provided in the detection head and detects a relative speed Xf, Xs relative to the scale; and a delay generation circuit which provides a time difference between two output request signals, the time difference being provided on the basis of a fine adjustment time tadj based on the relative speed Xf, Xs and the respective pieces of position information Xf, Xs on the two tracks, the output request signals St1, St2 urging the first and second position detection circuits to output the pieces of position information on Xf, Xs the two tracks.

Abstract: Disk drives with servo systems are described that include a servo ID pattern (SID) with a SAM field, as well as, one or more Integrated Servo sequences designed to provide a redundant sync mark function. The write-to-read gaps are omitted before selected servo sector SIDs. For example, write-to-read gaps can be omitted before alternating servo sector SIDs. When in write-mode that allows writing an extended user data sector without a write-to-read gap, the servo system delays the servo gate assertion with respect to the following SID to accommodate the absence of the write-to-read gap, which means that the SAM field cannot be read, but the Integrated Servo sequence(s) can be read and detected by the digital filters. Embodiments of the invention include sync mark timing for each SID (not just every other SID) even when writing extended user data sectors by using the Integrated Servo sequences to provide a sync timing function.

Abstract: An authentication method for authenticating an article in a device includes the steps of (a) reading an identification number stored on the article, (b) reading an authentication number stored on the article, (c) determining an input number based at least in part on the identification number, (d) applying an authentication function to the input number to calculate an output number, (e) determining that the article is authentic only if the authentication number corresponds to the output number, and (f) permitting use of the article in the device if the article is authentic, and disabling use of the article in the device if the article is not authentic.

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 method and apparatus is presented to determine a lateral position of a read/write head relative to a sequential information storage medium having a servo signal encoded therein and moving adjacent to the read/write head, where the servo signal comprises a plurality of pulses. The method includes detecting the servo signal using the read/write head and calculating a timing interval between each of the pulses using a clock rate of a clock signal. The clock rate is then adjusted based upon the velocity of the sequential information storage medium.

Abstract: The present invention provides a method of generating magnetic reference patterns on a disk or other magnetic media. This involves writing a first magnetic reference pattern to the disk with a servo writer. The disk may then be transferred to a hard disk drive. Control circuitry within the hard disk drive may recognize the first magnetic reference pattern and then position a RW head within the hard disk drive based on the first magnetic reference pattern. As the RW drive is accurately positioned based on the first magnetic reference pattern a second magnetic reference pattern may be written to the disk using the RW head. The RW head location is determined based on the velocity and phase between the read-write head and servo setter marks contained within the first magnetic reference pattern.

Abstract: An information medium having digital signals recorded therein includes a disk having first and second recording surfaces. The digital signals are in the form of a data frame including a lead-in block and n data blocks. The lead-in block has a same format as the n data blocks. n block addresses are assigned to the n data blocks. Information identifying an area on the disk in which the n data blocks is recorded is assigned to the n data blocks. m data blocks (0<m<n) are recorded on the first recording surface, and remaining (n−m) data blocks are recorded on the second recording surface. The lead-in block is recorded at the head of the data frame, and includes information identifying an area on the disk in which the lead-in block is recorded, a number of recording surfaces, the block address of one of the m data blocks recorded last on the first recording surface, and the block address of a last one of the n data blocks in the data frame.

Abstract: The magnetic record/reproduce apparatus for recording and reproducing large amounts of data at ultra-high-speed using a perpendicular magnetic recording mode, comprises: at least a cylinder having a perpendicular magnetic recording layer provided on at least the inner or outer surface thereof; a plurality of magnetic heads arranged to face the perpendicular magnetic recording layer of the cylinder; a rotating means for rotating at least one of the cylinder and the plurality of magnetic heads in relation to the other; a linear driving means for moving at least the cylinder or the plurality of magnetic heads along the axial direction of the cylinder; and a record/reproduce means for recording and/or reproducing data on the perpendicular magnetic recording layer.

Abstract: A method of recording digital signals on a disk having at least a first recording surface and a second recording surface. The digital signals are in the form of a data frame including a lead-in block and n data blocks. The lead-in block has a same format as the n data blocks. The method includes the steps of assigning n block addresses to respective ones of the n data blocks, assigning, to each of the n data blocks, information identifying an area on the disk in which a respective one of the n data blocks is to be recorded, recording m data block (0<m<n) of the n data blocks on the first recording surface of the disk, recording remaining (n-m) data blocks of the n data blocks on the second recording surface of the disk, and recording the lead-in block at the head of the data frame.

Abstract: A portable, self-contained data acquisition and recording system is provided for monitoring ambulatory subjects. The system has micropower requirements and an extended recording capability between battery replacements. A prepolarized magnetic tape is employed and recording is accomplished by selectively reversing the polarization at a time when the tape is at rest. A microprocessor is provided for processing signals and for controlling circuit operation such as a tape drive incrementer. The microprocessor also controls the preprocessing and digitizing of signals for further processing by the microprocessor and enables the delivery of digital signals to be recorded to a magnetic tape head positioned in operative relationship with the magnetic tape. Selected circuits of the system are selectively powered up and powered down during monitoring as needed to provide continuous power control for optimization of power usage.

Abstract: A motor drive amount correction signal generating circuit (14) corrects a deviation of an intermittent feed amount of a magnetic tape (1) by using reverse rotation pulse groups (t.sub.1, t.sub.2, t.sub.3, etc.) or forward rotation pulse groups (t.sub.1 ', t.sub.2 ', t.sub.3 ', etc.) and if the deviation is beyond a permissible range, the level of the braking voltage generated from a motor drive circuit (7) is changed in the subsequent drive period in intermittent recording.

Abstract: A time interval measuring apparatus includes a single main counter, and a plurality of latch circuits each for latching the count content of the main counter every time a plurality of different pulses are supplied thereto. In this apparatus, one of the count contents, corresponding to two pulses to be measured, is substracted from the other thereof, thereby measuring the interval between the two pulses. This apparatus includes a circuit for stopping the count operation of the main counter before the count content of the main counter is latched, when a pulse is supplied, a circuit for storing the number of stop operations of the main counter performed within the time interval between the two pulses to be measured, and a circuit for correcting the time interval by a value corresponding to the count stop time, in accordance with the stored data representing the number of counter stop operations, when the time interval is obtained by subtracting the counter content from the latched content.

Abstract: A planar array of high track density magnetic heads is mounted on a piezoelectric structural member. The heads are in contact with an area of magnetic recording medium coated onto a stationary support member located adjacent the head array structure. A repetitive ramp voltage is applied to the piezoelectric member causing repetitive linear extension of the member with resultant relative motion between the head array and the medium. A position transducer provides a feedback signal which monitors the position of the head array in relation to the magnetic medium, and this feedback signal is used to servo control the motion of the head array. Recording and playback of the stored information occurs coincidentally with the movement of the head array relative to the medium.

Abstract: A reader/writer credit card modular assembly wherein a T-shaped vertically disposed rail member provides accurate positioning of a credit card relative to a read/write transducer and to a timing track transducer through a reference plane established by means of horizontally disposed pins carried by the rail member. The credit card is vertically supported on the pins which in conjunction with a built-in tool or gauge member adjustable parallel to the card enables accurate preadjustment for a plurality of electromagnetic transducer heads arranged to be moved across the front surface of the credit card effective thereby to read from or write upon the credit card in synchronism with a prerecorded timing track disposed adjacent and parallel to the credit card.

Abstract: An elongated magnetic tape has a pair of longitudinally extending servo track areas, one of which is closer to the longitudinal center of the tape than the other. The lateral space intermediate the servo areas receives data signals, while the space between said one servo area and one edge contains identification and address signals. The tape is particularly adapted for use with rotating head recorders having two gaps on the rotor, with an intergap distance slightly greater than the lateral extent of the servo areas. A recording or write gap precedes an immediately trailing reading or recovery gap. When the rotor gaps pass the one edge in the one servo area, the write gap senses the servo track; while the read gap senses the identification signals. The arrangement is such that prior to the time the write gap reaches the data recording area, the read gap has sensed the identification signals.