Switching period control of microwave assisted magnetic recording for pole erasure suppression

Patent metadata

Field	Value
Publication number	US-9799369-B2
Application number	US-201514950938-A
Country	US
Kind code	B2
Filing date	Nov 24, 2015
Priority date	Nov 24, 2015
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

A magnetic recording system for preventing data loss resulting magnetic oscillator current. The magnetic recording system includes a magnetic write head with a magnetic write pole, a magnetic oscillator near the magnetic write pole, and a write coil for magnetizing the write pole. Circuitry is connected with the magnetic write coil to supply a current to the write coil and connected with the magnetic oscillator to supply a current to the magnetic oscillator. The circuitry is configured to ensure that the current to the magnetic oscillator does not inadvertently magnetize the write pole after the magnetic write pole has demagnetized.

First claim

What is claimed is:

1. A magnetic recording system, comprising:
a magnetic write pole;
a write coil configured to magnetize the magnetic write pole;
a magnetic oscillator formed adjacent to the magnetic write pole, the magnetic oscillator being configured to cause an oscillating magnetic field; and
circuitry connected to the write coil and the magnetic oscillator, the circuitry being configured to ensure that current flow through the magnetic oscillator terminates before the write pole has completely demagnetized upon termination of writing.

2. The magnetic recording system as claim 1 wherein the circuitry is configured to shorten a time in which current flow through the magnetic oscillator stops upon shut down of the magnetic oscillator.

3. The magnetic recording system as in claim 1 , wherein the circuitry is configured to terminate current to the magnetic oscillator prior to terminating current to the write coil.

4. The magnetic recording system as in claim 1 , wherein the circuitry is configured to extend the time to demagnetize the write pole to ensure that electrical current flow through the magnetic oscillator has terminated before the write pole has demagnetized.

5. The magnetic recording system as in claim 1 , wherein the magnetic oscillator is a spin torque oscillator.

Assignees

• Western Digital Tech Inc

Inventors

• Tabata Satoshi
• Yamada Atsushi
• Kazusawa Michiya
• Shiimoto Masato

Classifications

• G11B5/465

  Arrangements for demagnetisation of heads · CPC title

• G11B5/40

  Protective measures on heads, e.g. against excessive temperature  (G11B5/31 takes precedence; protection against wear G11B5/255  {; protective structure of the head: see under structures, e.g. G11B5/3106}) · CPC title

• G11B5/3153

  including at least one magnetic thin film coupled by interfacing to the basic magnetic thin film structure · CPC title

• G11B5/235

  Selection of material for gap filler {(G11B5/232 takes precedence)} · CPC title

• G11B5/02 Primary

  Recording, reproducing, or erasing methods; Read, write or erase circuits therefor · CPC title