Abstract: An expiration configuration is encoded into non-volatile memory embedded in media, such as a tape cartridge. The encoded expiration configuration specifies if the media is expired and the action to perform if the media is expired. The action may be performed by an application that reads the encoded expiration configuration or by a media device hosting the media. An expiration data for the media may be stored in the encoded expiration configuration or in an external data record.

Abstract: The present invention provides a magnetic transfer method for transferring information by bringing a master carrier for magnetic transfer and a slave medium into close contact with each other and by applying a magnetic field for magnetic transfer, said master carrier of magnetic transfer comprising servo areas to be transferred from the master carrier to the slave medium and data areas not to be transferred, both on the same plane.

Abstract: A method of testing a performance of an HGA including a step of obtaining a displacement performance of a precise positioning actuator by driving this actuator to displace and by executing a track profile measurement of at least one thin-film magnetic head element.

Abstract: A write current circuit (40) adapted to drive a thin film write head (L0) of a mass media information storage device. The write current circuit includes a write current reference voltage circuit (42) adapted to selectively establish amplitude of a write current signal. The write current circuit further includes programming circuitry (M5-M10) driven such that several parameters of the write current waveform can be controlled, including the write current amplitude, overshoot amplitude and overshoot duration. The present invention achieves technical advantages by providing the ability to both produce an accurate write current, and also providing the ability to establish the write current waveform shape so that customers can optimize disk drive performance even when using different thin film write heads available from different suppliers.

Abstract: A method for controlling write current to a write head during data write on a hard disk drive is disclosed. A direct access storage device includes a rotating storage medium in which data are magnetically written, a write head for writing data in the rotating storage medium, and a write current control circuit for changing write current-value settings to be supplied to the write head according to a predetermined elapsed time from the beginning of a write operation.

Abstract: A method of expanding the on-track operational range of a disk drive based upon detection of an external vibration condition. The method involves detecting that a vibration state exists and, while the existence of the vibration state is detected, modifying the default on-track-declaration algorithm such that a data transfer operation can be completed in less time than if the default on-track-declaration algorithm was in use.

Abstract: A population of disk drives includes a first disk drive configuration that has a spindle motor made according to the spindle motor design and a second disk drive configuration that has a spindle motor made according to the spindle motor design. A population of spindle motors are manufactured according to a spindle motor design. Each of the spindle motors in the population of spindle motors has a track-following characteristic in a range. A first group of spindle motors that correspond to a first portion of the range are allocated to the first disk drive configuration. A second group of spindle motors that correspond to the second portion of the range are allocated either to the second disk drive configuration or to the first disk drive configuration.

Abstract: A data discriminating unit includes a data discriminator and a sync signal discriminator. A data sync signal is detected for the bit string discriminated from the output of the sync signal discriminator, and the data is demodulated for the bit string discriminated from the output of the data discriminator, thereby optimizing the signal to a form suitable for discrimination and detection of the data sync signal and demodulation for data reproduction. As a result, the detection performance of the data sync signal can be improved while maintaining the data discrimination performance. A Viterbi decoder is used for discrimination by the data discriminator and the sync signal discriminator for the optimization thereby to optimize the number of states, the number of paths for state transition and the path memory length. A signal having no continuous inversions of the recording data is used as the data sync signal.

Abstract: A nonlinear transition shift (NLTS) measurement procedure for read/write heads employing a giant magnetoresistive (GMR) merged heads. The method of this invention includes the pulse-shape distortion effects on recording nonlinearity, which can significantly affect the existing theoretical formulae for calculating nonlinearity correction factor from measured partial erasure values, and second-order approximation of equation of NLTS and nonlinearity correction factor. Transition broadening effects (TBE) and partial erasure (PE) are incorporated in the NLTS measurement procedure to permit accurate isolation of the NLTS from the unrelated TBE/PE and GMR nonlinear transfer characteristic (NTC). First, a fifth harmonic elimination (5HE) test is performed at bit period T to measure a first nonlinearity value X.

Abstract: A phase error estimate value between an actual interpolated sample time and an ideal interpolated sample time of an analog signal is selected by circuitry based on a quotient (z2−z0)/(z3−z1), where z0, z1, z2, and z3 are four successive synchronous samples of the analog signal. A sign of the phase error estimate value is selected by circuitry based on a comparison of predetermined differences between the four successive synchronous samples. The phase error estimate value can be adjusted by circuitry when an absolute value of the phase error estimate value exceeds a predetermined threshold and a closest sampling phase according to a difference between (z2−z0) and (z3−z1) differs from a phase predicted by a hysteresis state.

Abstract: The present invention provides a magnetic transfer method for transferring information by bringing a master carrier for magnetic transfer and a slave medium into close contact with each other and by applying a magnetic field for transfer, said master carrier comprising servo areas and data areas, said servo areas are convex, and difference of height between the data areas and the servo areas is within the range of 50-800 nm.

Abstract: A magnetic card reader for causing a magnetic card to make a move relative to a magnetic head and reproducing data on the magnetic card by the magnetic head, said magnetic card reader includes an amplifier for amplifying a magnetic signal provided by the magnetic head, a peak detection section for detecting a peak point of amplifier output from the amplifier output, a data reproduction section for reproducing digital data based on the interval between the peak points, an anomaly detection section for detecting an anomaly of the peak point interval and an output value storage section for converting the amplifier output from analog form into digital form every predetermined time and storing the provided data.

Abstract: Copying, dubbing or reproducing copyrighted digital data can be inhibited or restricted to properly protect a copyright. AV data recorded on a pre-recorded tape is output from a reproducing unit of a first digital VCR with protective information indicating whether the copy of the AV data is inhibited or not. The protective information is input with the A/V data to a second digital VCR. Copy permission information of a blank tape loaded in the second digital VCR is discriminated and the second digital VCR records the AV data supplied from the first digital VCR based on the protective information and the copy permission information.

Abstract: A method and apparatus are provided for implementing adaptive reordering of data recovery procedure (DRP) steps in a direct access storage device (DASD). An initial set of DRP steps is stored. A reorder table is stored during the operation of the DASD. The reorder table includes data recovery data for each data head of successful predefined DRP step numbers. When a DRP process is started, checking for a modified DRP step is performed using the reorder table. Responsive to not identifying the modified DRP step, file parameters for a DRP read operation are set based on the initial set of DRP steps. Responsive to identifying the modified DRP step, file parameters for a DRP read operation are set based on a reordered DRP step that is identified by using the stored successful predefined DRP step numbers in the reorder table. When a successful DRP read operation is identified, the data recovery data in the reorder table are updated.

Abstract: A magnetic medium write precompensation circuit produces a precisely controlled delay for magnetic medium write precompensation by digital-to-analog converting a data value, low-pass filtering the digital-to-analog converted signal, and limiting the filtered signal to produce a desired time delay. One or more of the digital-to-analog conversion levels, limiting levels, and filter cutoff levels determines the amount of the delay. Feedback control may be employed to adjust the digital-to-analog conversion level, filtering, and/or the limiting level to thereby adjust the compensation time delay.

Abstract: A detector (55) and method for detecting a synchronization servo mark (SSM) in a data stream of mass data storage device (10) has a matched filter (56) to receive the data stream. The filter (56) produces a maximum output when the SSM is applied. A delay element receives (64) the matched filter output to produce a delay element output (72). When the delay element output (72) is greater than a predetermined threshold value (Vth) and is larger than the output value (74), the (SSM) is in a current time location. When the “D” element output (72) is greater than the predetermined threshold value (Vth) and less than the output value, the SSM is in the next time location. The threshold may be established to be less than maximum if the phase of the SSM is within a predetermined phase range.

Abstract: A magnetic recording element is composed of a first magnetic film to generate spin vortex by an external magnetic field and a second magnetic film having a magnetization perpendicular to the surfaces thereof, and also an insulating layer to control (repress) a current through the magnetic recording element which is formed between the first magnetic film and the second magnetic film. A given external magnetic field is applied to the magnetic recording element, to generate a spin vortex in the first magnetic film and then, generate a vertical magnetization at the center of the spin vortex. Then, a given data is written on the vertical magnetization.

Abstract: A dynamic method and apparatus are provided for controlling head fly characteristics in a disk drive. A plurality of charge surfaces is provided with a transducer head slider assembly. At least one head fly characteristic is monitored during operation of the disk drive. An identified current head fly characteristic is compared with a predefined head fly characteristic to identify a difference value. A charge and potential of the plurality of charge surfaces are dynamically controlled responsive to the identified difference value. Dynamically controlling the charge and potential of the plurality of charge surfaces enables both dynamically controlling flyheight of the transducer head slider assembly and dynamically controlling angles of the transducer head slider assembly relative to an associated disk surface.

Abstract: A magnetic transfer apparatus writing a servo signal by magnetically transferring to a magnetic recording medium, and an optical type inspection apparatus for optically inspecting scratch or foreign matter on the magnetic recording medium wherein a characteristic grease is used for these apparatuses are disclosed. Grease used in the magnetic transfer apparatus or the optical type inspection apparatus generates sulfur type gas in amount less than or equal to 0.5 ppb.

Abstract: A magnetic recording disk drive with patterned disk media, wherein discrete magnetic data blocks representative of the individual data bits are isolated from one another, uses the discrete data blocks as the source of the clocking signal to the write head. The carrier for the read/write head includes a special pattern sensor that senses the data blocks in the data tracks before they pass beneath the write head. The pattern sensor output serves as the clocking signal to precisely control the placement of the write pulses by the write head. A time delay is calculated using a timing mark on the patterned disk to delay the write pulses so that a data block sensed by the pattern sensor is the same data block to which the write pulse is applied. In this manner the actual previously recorded data provides the synchronization or clocking signal to control the writing of the new data.