Patent application number | Description | Published |
20130021691 | MAGNETIC STORAGE DEVICE WITH CHIRPED WRITE HEAD DEGAUSSING WAVEFORM - A circuit for use with a memory storage device including a magnetic storage medium and a write head operative to subject the magnetic storage medium to a magnetic field in response to an application of current to the write head, includes a write circuit operative to generate a write current supplied to the write head. The write current is characterized by a current waveform that reverses polarity in accordance with data to be stored on the magnetic medium. The circuit for use with the memory storage device further includes a degauss circuit operative to generate a degaussing current supplied to the write head. The degaussing current is characterized by a current waveform that oscillates between opposite polarities with an amplitude and a frequency that change over time. | 01-24-2013 |
20130083419 | DISK-BASED STORAGE DEVICE HAVING WRITE SIGNAL COMPENSATION FOR MAGNETIZATION POLARITY OF ADJACENT BITS - A hard disk drive or other disk-based storage device comprises a storage disk, a read/write head configured to read data from and write data to the storage disk, and control circuitry coupled to the read/write head and configured to process data received from and supplied to the read/write head and to control positioning of the read/write head relative to the storage disk. The control circuitry is further configured to adjust at least one parameter of a write signal for a target bit to be written to the storage disk based on respective magnetization polarities of one or more adjacent bits previously written to the storage disk. | 04-04-2013 |
20130128375 | Magnetic Recording System With Multi-Level Write Current - Various embodiments of the present invention provide apparatuses, systems and methods for magnetic recording with a multi-level write current waveform. For example, an apparatus for magnetic recording with a multi-level write current waveform is disclosed that includes a pattern detection circuit operable to detect patterns in data to be written by the magnetic write head and to yield a pattern indicator signal, and a write driver operable to generate the multi-level write current waveform for the magnetic write head. At least one electrical characteristic of the multi-level write current waveform is based upon the patterns detected by the pattern detection circuit. | 05-23-2013 |
20130235485 | STORAGE DEVICE HAVING WRITE SIGNAL WITH MULTIPLE-SLOPE DATA TRANSITION - A hard disk drive or other disk-based storage device comprises a storage disk, a read/write head configured to read data from and write data to the disk, and control circuitry coupled to or otherwise associated with the read/write head. The control circuitry comprises a write driver configured to generate a write signal for data to be written to the storage disk, and a multiple-slope transition controller associated with the write driver and configured to control a data transition in the write signal such that the data transition comprises at least two different segments each having a different slope, with the transition controller comprising separate slope control mechanisms for each of the segments. By way of example, the data transition may comprise a dual-slope transition having first and second segments arranged sequentially between a start point and an end point of the data transition. | 09-12-2013 |
20130271867 | STORAGE DEVICE HAVING DEGAUSS CIRCUITRY WITH SEPARATE CONTROL OF DEGAUSS SIGNAL STEADY STATE AND OVERSHOOT PORTIONS - A hard disk drive or other disk-based storage device comprises a storage disk, a write head configured to write data to the disk, and control circuitry coupled to the write head. The control circuitry comprises a write driver and degauss circuitry associated with the write driver. The degauss circuitry is configured to control a degauss signal waveform to be applied to the write head by the write driver, and comprises separate amplitude envelope control mechanisms for steady state and overshoot portions of the degauss signal waveform. The separate amplitude envelope control mechanisms may comprise, for example, separate steady state and overshoot controllers for controlling the amplitude envelope decay rates of the respective steady state and overshoot portions of the degauss signal waveform over the plurality of pulses. | 10-17-2013 |
20140071561 | STORAGE DEVICE HAVING DEGAUSS CIRCUITRY GENERATING DEGAUSS SIGNAL WITH MULTIPLE DECAY SEGMENTS - A hard disk drive or other disk-based storage device comprises a storage disk, a write head configured to write data to the disk, and control circuitry coupled to the write head. The control circuitry comprises a write driver and degauss circuitry associated with the write driver. The degauss circuitry is configured to generate a degauss signal to be applied to the write head by the write driver. The degauss signal has a waveform comprising a plurality of decay segments including at least one alternating current decay segment and at least one direct current decay segment. An initial decay segment of the plurality of decay segments may comprise an alternating current decay segment or a direct current decay segment, and may be immediately followed by a decay segment of the opposite type. | 03-13-2014 |
20140111617 | OPTICAL SOURCE DRIVER CIRCUIT FOR DEPTH IMAGER - A depth imager such as a time of flight camera comprises a driver circuit and an optical source. The driver circuit comprises a frequency control module and a controllable oscillator having a control input coupled to an output of the frequency control module. An output of the controllable oscillator is coupled to an input of the optical source, and a driver signal provided by the driver circuit to the optical source utilizing the controllable oscillator varies in frequency under control of the frequency control module in accordance with a designated type of frequency variation, such as a ramped or stepped variation. The driver circuit may additionally or alternatively comprise an amplitude control module, such that a driver signal provided to the optical source varies in amplitude under control of the amplitude control module in accordance with a designated type of amplitude variation. | 04-24-2014 |
20140240864 | STORAGE DEVICE HAVING DEGAUSS CIRCUITRY CONFIGURED FOR GENERATING DEGAUSS SIGNAL WITH ASYMMETRIC DECAY ENVELOPES - A hard disk drive or other storage device comprises a storage medium, a write head configured to write data to the storage medium, and control circuitry coupled to the write head. The control circuitry comprises degauss circuitry coupled to or otherwise associated with one or more write drivers. The degauss circuitry is configured to generate an asymmetric degauss signal to be applied to the write head. The asymmetric degauss signal has a waveform with upper and lower decay envelopes that are asymmetric about a specified degauss current level, such as a substantially zero current level. | 08-28-2014 |