公开(公告)号：US09607642B1

公开(公告)日：2017-03-28

申请号：US15007728

申请日：2016-01-27

Applicant: Seagate Technology LLC

Inventor： Won Choul Yang ,  Jin Pil Kim ,  Shi Jung Kim

IPC: G11B5/60

CPC classification number: G11B5/6076 ,  G11B5/6035 ,  G11B5/607

Abstract: An AC signal having a specified frequency and a DC offset voltage is applied to a slider substrate or a magnetic recording medium. A low- or non-modulation interface is defined between the slider and medium. In response to applying the AC signal, an oscillation in an electrostatic force occurs between the slider and the medium at the specified frequency, which causes an oscillation in thermal sensor signal at the slider, which oscillates at the specified frequency. A heater of the slider is adjusted to decrease spacing between the slider and medium during oscillation of the electrostatic force. For each heater adjustment, thermal sensor resistance is measured over a specified number of medium revolutions. Head-medium contact is detected using one of an amplitude of a harmonic of the thermal sensor signal and a summation of amplitudes of all frequency components at the specified frequency.