公开(公告)号：US09928881B1

公开(公告)日：2018-03-27

申请号：US15711790

申请日：2017-09-21

Applicant: Seagate Technology LLC

Inventor： Zhe Shen ,  Zuxuan Lin ,  Lei Lu ,  Jianhua Xue

IPC: G11B5/09 ,  G11B20/10 ,  G11B27/36 ,  G11B5/455 ,  G11B5/012 ,  G11B5/00 ,  G11B5/55

CPC classification number: G11B27/36 ,  G11B5/012 ,  G11B5/455 ,  G11B5/4555 ,  G11B5/5552 ,  G11B20/10009 ,  G11B20/10481 ,  G11B20/10509 ,  G11B2005/0013

Abstract: A method of testing a dynamic write field of a recording head includes preparing a test magnetic medium and recording a write signal on the test magnetic medium with the write signal being set at a first write parameter and a second write parameter. An average of multiple read-back signals of the recorded write signal are captured to determine an average amplitude of the read-back signals. The recording of the write signal on the test magnetic medium and the capturing of the average of multiple read-back signals of the recorded write signal are repeated to determine the average amplitude of the read-back signals by fixing the first write parameter of the write signal and changing the second write parameter of the write signal until the average amplitude of the read-back signals saturates.

公开(公告)号：US09928858B1

公开(公告)日：2018-03-27

申请号：US15702571

申请日：2017-09-12

Applicant: Seagate Technology LLC

Inventor： Zhe Shen ,  Zuxuan Lin ,  Lei Lu ,  Jian Zhong

IPC: G11B5/31 ,  G11B19/04 ,  G11B5/11 ,  G11B5/127

CPC classification number: G11B5/3116 ,  G11B5/11 ,  G11B5/1278 ,  G11B5/315 ,  G11B5/3166 ,  G11B5/3196 ,  G11B19/048

Abstract: A method that includes supplying a predetermined signal to a write head having side shields. The method also includes performing, by the write head, a recording operation on a surface of a data storage medium, when the predetermined signal is supplied to the write head, to provide a recorded magnetization pattern. The method further includes carrying out measurements on a portion of the recorded magnetization pattern influenced by a magnetization of the side shields. The measurements are employed to determine whether a reversed side shield magnetization condition is present in the write head.