Patent ID: 7796353
Filing Date: 2010-09-14
Classification: B82Y,G11B

Abstract:
1. A patterned-media magnetic recording disk drive comprising: a rotatable magnetic recording disk having a plurality of data tracks, each data track patterned into discrete pillars containing magnetizable material and separated by nonmagnetic recesses; a radiation source; an optical waveguide for the transmission of radiation from the radiation source to the disk; a near-field transducer maintained near the surface of the disk; a radiation detector for detection of radiation from the near-field transducer and providing an output signal that varies in response to whether the near-field transducer is near a pillar or a recess; wherein the disk contains optical contrast material in the recesses for enhancing the contrast between radiation from the near-field transducer when it is near a pillar and radiation from the near-field transducer when it is near a recess; a write head for generating write pulses to magnetize the pillars as the disk rotates; and a write clock responsive to the radiation detector output signal and coupled to the write head for controlling the write pulses generated by the write head.