Patent application number | Description | Published |
20130301156 | ADJUSTING A PREAMP WRITE CURRENT TO APPLY AN ASYMMETRIC SIGNAL AT A WRITE HEAD - A first parameter associated with a writer preamp is defined. A write current of the writer preamp is adjusted in accordance with the first parameter so that an asymmetric signal is applied at a write head. The asymmetric signal results in symmetric writing of bits to a medium. | 11-14-2013 |
20140029396 | HEAT ASSISTED MAGNETIC RECORDING DEVICE WITH PRE-HEATED WRITE ELEMENT - An apparatus includes a write element configured to apply a magnetic field to write data on a portion of a heat-assisted magnetic recording media in response to an energizing current. An energy source is configured to heat the portion of the media being magnetized by the write element. A preheat energizing current is applied to the write element during an interval before writing the data to the portion of the media. The preheat energizing current does not cause data to be written to the media and brings at least one of the write element and driver circuitry into thermal equilibrium prior to writing the data on the portion. | 01-30-2014 |
20140334274 | MAGNETIC RECORDING LASER DIODE CONTROL - Controlling a laser diode involves activating a first current source in preparation for writing to a magnetic recording medium. The first current source applies a threshold current to a laser diode that brings the laser diode close to an operating point. Responsive to a write signal, a second current source is activated that applies a write current to the laser diode. A combination of the write current and the threshold current fully energizes the laser diode and is less than a target recording current. Coincident with the activation of the second current source, a photodiode is activated that is optically coupled to the laser diode. The activated photodiode causes a feedback current to be applied to the laser diode. | 11-13-2014 |