Abstract: Provided is a method of magnetic transfer. The method includes initially DC-magnetizing a transfer-recipient disc in a circumferential direction, by applying a magnetic field to the transfer-recipient disc in the circumferential direction thereof bringing initially DC-magnetized transfer-recipient disc and a master disc into close contact with each other, on the top side of the master disc a magnetic layer including a great number of protrusions that configure a magnetic pattern being formed; and executing magnetic transfer in such a way that a magnetic-field generation device is provided, and that, when a magnetic field is applied in a circumferential direction to the transfer-recipient disc and the master disc, transfer of the magnetic pattern of the master disc onto the transfer-recipient disc occurs.

Abstract: Magnetic tape read channel signal values are developed employing intermediate bits of the path memory of a PRML Viterbi detector. Identification logic identifies a most likely path memory state of the PRML Viterbi detector from the path metrics of the PRML Viterbi detector. An intermediate bit sequence of the identified most likely path memory state is obtained, the intermediate bit sequence extending from an initiation point of the path memory which is intermediate the output and the input of the PRML Viterbi detector. A sample value is determined which corresponds to the obtained intermediate bit sequence.

Abstract: A data storage device executes sector guarantee processing at an unexpected power supply disconnection. The sector guarantee processing can be accurately performed even if the fluctuation of power supply voltage during normal operation is high. The voltage of the power supply is monitored via an A/D converter. The control unit calculates a voltage change value, which is a relative value of the detected voltage of the power supply, and judges power supply disconnection by the level of the voltage change value, to perform sector guarantee processing. The voltage fluctuation during normal operation and the voltage fluctuation at power supply disconnection can be distinguished, power supply disconnection can be accurately detected, and write disable status can be judged.

Abstract: A write driver circuit for a magnetic storage medium includes a first write driver sub-circuit that has an output that communicates with a first node of a write head. The first write driver circuit includes a first driver circuit and a first feedback path between the input and the output of the first driver circuit. A second write driver sub-circuit has an output that communicates with a second node of the write head. The second write driver sub-circuit includes a second driver circuit and a second feedback path between the input and the output of the second driver circuit. The write driver circuit has a substantially constant output impedance during operation, balanced differential and common mode resistances, and a substantially constant common mode voltage across the write head during operation.

Abstract: One or more methods and systems are presented for performing gain and timing acquisition of data read from one or more data sectors of a hard disk drive. The gain and timing information may be used to synchronize a read channel receiver of the hard disk drive to the data read from the data sector(s). In a representative embodiment, the one or more methods comprises determining one or more frequency and phase offsets using one or more preambles of one or more data sectors residing in a hard disk drive. In a representative embodiment, the gain of the one or more preambles may be determined. In another representative embodiment, the one or more systems used to determine one or more phase and frequency offsets, and amplitudes, comprise hardware and/or software capable of utilizing a sequence of consecutive samples provided by one or more preambles of one or more data sectors.

Abstract: In one embodiment, a surface analyzer system comprises a radiation targeting assembly to target radiation onto a surface, a reflected radiation collecting assembly that collects radiation reflected from the surface, and a signal processing module. The signal processing module generates an image of magnetic characteristics of the magnetic disk, wherein the image comprises a plurality of servo sector arcs, locates a sample of points on a plurality of the servo sector arcs, fits a circle to the sample of points on each of the plurality of servo sector arcs, and determines at least one pivot-to-gap measurement from the radius of the circles.

Abstract: A mechanical transport device includes a system for transport; and a hard disk drive attached to the system. The hard disk drive comprises a magnetic recording disk to record data, a head to read or write the data to or from the disk, and a drop sensor designed to sense a shock condition. The system for transport may be a vehicle such as a car.