Abstract: An assembly for writing/reading high-density data on a recording media as a series of tags comprising a magnetic information bit pattern. The assembly includes an antenna positionable near the media; a source of electromagnetic radiation for producing an incident wave at least a portion of which can be coupled to the antenna; and, a means for coordinating a mutual positioning of the source of the electromagnetic radiation and the antenna, so that the antenna can generate a highly localized electromagnetic field in the vicinity of the media for inducing localized heating of the media. The assembly is capable of writing/erasing said high-density data by using an information signal for modulating the localized field generated in the vicinity of the media; the assembly is capable of reading by coordinating the mutual positioning of the antenna and the media.

Abstract: An apparatus and method for adding errors to magnetic data and then detecting the errors is revealed. The method includes providing a magnetic recording channel, reading and digitizing a stored signal, introducing an error signal that emulates off-track interference, adding the error to the digitized signal, and determining an error rate. The apparatus includes a magnetic recording channel having a linear feedback shift register to generate a pseudo-random binary sequence, circuitry to convert the sequence into an error signal, and a Viterbi detector to quantify an error rate.

Abstract: Disclosed herein is a control system designed to position a head provided in a magnetic disk drive. The system has a controller, a signal output section, two gain/phase control sections and an adder. The controller receives data generated from position data extracted from servo data and representing the position of the head and generates, form the data, an operation signal. The operation signal is used in seek control or track following control to move the head to a target position. The signal output section distributes the operation signal to the gain/phase control sections. The gain/phase control sections adjust the phase and gain of the operation signal, independently of each other, generating gain/phases. The operation signals are supplied to the adder. The adder adds the signals, generating a control signal that has a gain smaller than the gain of the operation signal. The control signal is input to the object which is provided in the magnetic disk drive and which is to be controlled.

Abstract: A signal recording apparatus including a battery voltage detecting circuit. The battery voltage detecting circuit detects the voltage value of a battery. When a record button provided on an operation panel is pressed, a syscon detects, for 160 ms, voltage values given from the battery voltage detecting circuit. The detected voltage values are stored to a DRAM. An average calculated of the voltage values of for 160 ms by using the DRAM. The syscon compares the averaged voltage value with a threshold A that makes it possible for recording for one disk. When the averaged voltage value is equal to or higher than the threshold A, the syscon directly starts recording. When the averaged voltage value is lower than the threshold A, an insufficient remaining capacity of the battery is displayed on a liquid crystal panel by a display controller.

Abstract: A conventional magnetic head has a structure, in which a MR element and a recording element are stacked. The influence of a recording magnetic field on the magnetically sensitive portion of a reproduction element is lessened and the performance of the MR element is stabilized. Also, the reliability of the magnetic disk drive using a MR element is enhanced. The magnetic disk drive uses a composite magnet head, which has a plurality of reproduction elements arranged such that the magnetically sensitive layer of a reproduction element of the composite magnetic head does not overlap with the normal direction projection of the recording element, and which lessens the influence of a recording magnetic field on the magnetically sensitive portion of each reproduction element.

Abstract: In magnetic transfer performed to transfer an information signal such as a servo signal from a master medium to a slave medium, the degradation of transfer quality caused by a failure of close contact between the master medium and the slave medium due to dust accumulated thereon is prevented. Magnetic transfer means is provided to carry out the magnetic transfer by bringing the master medium bearing information and the slave medium into close contact with each other, and applying a transfer magnetic field. Replacing means is provided to prepare a plurality of master media, and replacing the master medium after magnetic transfer is performed a predetermined number of times. Cleaning means is also provided to clean the replaced master medium by ultrasonic washing or the like.

Abstract: Adjustment of a read detection equalizer filter of a magnetic tape drive is conducted utilizing a required control pattern signal which comprises a required portion of a normal recording format of the magnetic tape. An example comprises a data set separator signal. The sensed required control pattern signal is processed with respect to a target reference pattern signal to adapt the read detection equalizer filter to the target reference pattern signal.

Abstract: Magnetic recording media with thermal fluctuation resistance and low noise made compatible are obtained by using as magnetic layers a combination of a first magnetic material having a first Curie point higher than the recording temperature and a second magnetic material having a second Curie point higher than the operation temperature of the apparatus and lower than the recording temperature, a combination of a ferromagnetic material having a Curie point higher than the recording temperature and an antiferromagnetic material having a Neel point higher than the operation temperature of the apparatus and lower than the recording temperature.

Abstract: A method for performing error correction code operations on data to be read from the disk (12) of a hard disk drive (10) includes applying a first error correction code algorithm to a first set of data to be written to the hard disk drive, and a second error correction code algorithm, different from the first, to a second set of data to be written to the hard disk drive (10). The first and second error correction code algorithms may for example produce a different number of error correction code bits for application to said data. The selection between the first and second algorithms may be made, for instance, in dependence upon the physical locations (76, 78) on the disk, or in dependence upon the type of said data (80) to be written. By reducing the number of ECC bits that need be associated with at least some of the data to be written to the disk (12), the available space on the disk for user data can be increased.

Abstract: An apparatus and method for transferring data between a read/write transducer coupled to a data channel and a data storage medium eliminates the necessity of a data sector block coding pad field. A data sector is received during a read operation. A disable signal associated with a last block of the data sector is generated. In response to the disable signal, data correction, such as parity correction, to the last block of the data sector is disabled. Data correction is enabled for application to blocks of the data sector other than the last block. Generating the disable signal involves identifying the last block of the data sector, which may be accomplished by detecting a change of state of a read gate input into the data channel or by use of a counter. The apparatus and method of the present invention may be embodied within a data channel of a data storing system, such as a direct access storage system.

Abstract: A method for forming a magnetic pattern by applying a first external magnetic field to a magnetic recording medium having a magnetic layer to magnetize uniformly the magnetic layer in a predetermined direction and heating locally the magnetic layer while a second external magnetic field is applied thereto, whereby the heated portion is magnetized in the direction opposite to the predetermined direction, wherein the second external magnetic field has a pulse-like magnetic field component. The method can form a fine magnetic pattern efficiently in a medium for high density recording, and a magnetic recording medium and a magnetic recording device capable of recording with high density can be provided economically in a short time.

Abstract: Each of data bands of a magnetic tape includes a plurality of wraps as data tracks. In the read/write test, a predetermined test length is set to every wrap and test patterns are written to the test length portion, and the patterns are read so as to verify whether or not there is trouble to the drive or the tape. While it takes time to switch a magnetic head among the wraps on testing all the wraps, the time depends on order of switching. In the present invention, the order in which the magnetic head switches the wraps for reading or writing, that is, a wrap sequence, is selected to be different from the wrap sequence in an actual active state. The wrap sequence in the actual active state has been selected based on a factor such as writing performance of the tape, which has not been suited to the read/write test.

Abstract: A common mode transient reduction circuit for use with an operational transconductance amplifier having a main amplifier and a common mode feedback amplifier coupled to a common bias voltage is disclosed. The common mode transient reduction circuit includes a delay circuit, coupled between the common bias voltage and the main amplifier, that reduces a magnitude of the main amplifier's common mode voltage output transient when the common bias voltage is changed. In an advantageous embodiment, the delay circuit includes a resistance and a capacitance.

Abstract: A method and apparatus to optimize a bit error rate for a partial response, maximum likelihood (“PRML”) read/write channel is disclosed. A channel margining circuit that is configured to carry out an embodiment for a method of optimizing the bit error rates of a read/write channel is described. The margining circuit derives an interference signal to stress a read/write channel for optimizing the bit error rate. The signal is derived from bit errors inherent with the read/write channel. The circuit reduces the time to optimize the channel by providing an amplified interference signal that increases a bit error rate during optimization.

Abstract: A method and apparatus for reducing retry redundancy during disc read operations in a disc drive system are provided in which a number of physical sectors to be read from the disc during read operations is first determined. An attempt is then made to read all sectors of the number of sectors during a first disc revolution. Failed sectors of the number of sectors during the first disc revolution are also identified. A retry cycle is then performed on the failed sectors during a second disc revolution following the completion of the attempt to read all sectors of the number of sectors during the first revolution.

Abstract: The present invention provides a method and apparatus for performing automated spin valve combined pinned layer reset and hard bias initialization at the head gimbal assembly level. The reset combines a current pulse with an assisting magnetic field. The pinned layer reset and hard bias initialization is automated and performed by a single tool at the head gimbal assembly level to increase manufacturing throughput.

Abstract: An optical device to control the output power of a laser on recording and reproduction without expensive high-speed circuits is provided. The optical disk device of the present invention comprises monitor portion for monitoring the power of laser light, averaged light quantity calculating portion for calculating the averaged light quantity of the power of the laser light, memory portion for memorizing the averaged light quantity, error quantity calculated portion for calculating the difference between the output signals of the averaged light quantity calculating portion and the memory portion, and laser power control portion for controlling the power of the laser light in response to the output signal from the error quantity calculating portion.

Abstract: A differential circuit to read differential data from a disk by a voltage bias includes a read circuit having a read circuit pole to read the differential data from the disk by maintaining the voltage bias and a feedback circuit having a feedback pole to sense deviations in the voltage and to adjust the voltage in response to the deviations. The read circuit pole is separated from the feedback pole in frequency.

Abstract: A method for the adaptive dampening of a peak amplitude of a thermal asperity signal in a disc drive to minimize loss of read data integrity, including the steps of determining a peak-to-peak preamble signal amplitude for identifying an amplitude signal range of the peak amplitude of the thermal asperity signal; measuring the peak amplitude of the thermal asperity signal; separating the peak-to-peak preamble signal amplitude into substantially even portions for use in calculating a value of the amplitude signal range of the peak amplitude of the thermal asperity signal; calculating the value of the amplitude signal range of the peak amplitude of the thermal asperity signal for use in determining a dampening resistance used by a dampening circuit to adaptively dampen the peak amplitude of the thermal asperity signal; and activating the dampening circuit to dampen the peak amplitude of the thermal asperity signal.

Abstract: A recording head for use in conjunction with a magnetic storage medium, comprises a waveguide for providing a path for transmitting radiant energy, a near-field coupling structure positioned in the waveguide and including a plurality of arms, each having a planar section and a bent section, wherein the planar sections are substantially parallel to a surface of the magnetic storage medium, and the bent sections extend toward the magnetic storage medium and are separated to form a gap adjacent to an air bearing surface, and applying a magnetic write field to sections of the magnetic recording medium heated by the radiant energy. A disc drive including the recording head and a method of recording data using the recording head are also provided.