Patent ID: 9659588
Date: 2017-05-23
CPC Classifications: G11B

Claim:
1. A thermally-assisted magnetic recording head comprising: a medium facing surface configured to face a recording medium; a coil for producing a magnetic field corresponding to data to be written on the recording medium; a main pole having a front end face located in the medium facing surface; a waveguide including a core and a cladding, the core allowing light to propagate therethrough, the cladding being provided around the core; a plasmon generator having a near-field light generating surface located in the medium facing surface; a surrounding layer; and a gap film for separating the plasmon generator from the surrounding layer, wherein the main pole is configured to pass a magnetic flux corresponding to the magnetic field produced by the coil, and to produce from the front end face a write magnetic field for use to write the data on the recording medium, the plasmon generator is configured to excite a surface plasmon on the plasmon generator based on the light propagating through the core, and to generate near-field light from the near-field light generating surface based on the surface plasmon, the front end face of the main pole includes a first end face portion, and a second end face portion contiguous with the first end face portion, the second end face portion is greater than the first end face portion in width in a track width direction, the near-field light generating surface, the first end face portion and the second end face portion are arranged in this order along a direction of travel of the recording medium, the main pole includes a first portion and a second portion, the first portion including the first end face portion, the second portion including the second end face portion, the surrounding layer has a first surrounding layer end face and a second surrounding layer end face, both located in the medium facing surface, the first surrounding layer end face and the second surrounding layer end face are located on opposite sides of at least part of the first end face portion in the track width direction so that the at least part of the first end face portion is interposed between the first and second surrounding layer end faces, the gap film has a first gap film end face and a second gap film end face, both located in the medium facing surface, the first gap film end face and the second gap film end face are located on opposite sides of at least part of the near-field light generating surface in the track width direction so that the at least part of the near-field light generating surface is interposed between the first and second gap film end faces, each of the first and second gap film end faces includes a portion located between the first and second surrounding layer end faces, but does not include any portion interposed between the first surrounding layer end face and the first end face portion or between the second surrounding layer end face and the first end face portion, the first end face portion has a first edge closest to the near-field light generating surface, and a second edge located at a boundary between the first end face portion and the second end face portion, the near-field light generating surface has a third edge closest to the first end face portion, and respective midpoints of the first to third edges are located collinearly with one another, and the midpoint of the first edge lies on the first edge.