Patent ID: 9502053
Filing Date: 2016-11-22
CPC Classification: G11B,Y10T

Claim Text:
1. A magnetic head for perpendicular magnetic recording, 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 an end face located in the medium facing surface, the main pole being configured to pass a magnetic flux corresponding to the magnetic field produced by the coil, and to produce a write magnetic field for use to write the data on the recording medium by means of a perpendicular magnetic recording system; a write shield; and a gap section formed of a nonmagnetic material and located between the main pole and the write shield, wherein the write shield includes a trailing shield located on a front side in a direction of travel of the recording medium relative to the main pole, the trailing shield includes a first portion, a second portion, a third portion and a fourth portion each of which is formed of a magnetic material, the first portion has a first end face located in the medium facing surface, and a first top surface located at a front-side end of the first portion in the direction of travel of the recording medium, the first end face being on the front side in the direction of travel of the recording medium relative to the end face of the main pole, the second portion has a second end face located in the medium facing surface, and a second top surface located at a front-side end of the second portion in the direction of travel of the recording medium, the third portion has a third end face located in the medium facing surface, and a third top surface located at a front-side end of the third portion in the direction of travel of the recording medium, the second end face and the third end face are located on opposite sides of the first end face in a track width direction, the first to third top surfaces are coplanar with each other, the fourth portion lies on the first to third top surfaces and has a fourth end face located in the medium facing surface, and the first portion is higher in saturation flux density than the second to fourth portions.