Magnetic Recording Head Magnetization Switching for Pole Erasure
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Solution Overview
Problem
The longitudinal magnetic recording method experiences instability due to heat fluctuations as recording density increases, leading to the need for a perpendicular magnetic recording method, but existing perpendicular magnetic recording heads face challenges in balancing writing efficiency and preventing 'Pole erasure'.
Innovation Solution
A magnetic recording head with a main magnetic pole containing a ferromagnetic layer and an antiferromagnetic main magnetic pole-magnetization fixing portion, where a heater is used to reduce magnetic interaction between the main magnetic pole and the fixing portion, allowing the magnetization to be directed perpendicular to the recording medium during writing, thereby enhancing writing efficiency and mitigating Pole erasure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a perpendicular magnetic recording head is used to achieve perpendicular magnetic recording, then signal stability is improved, but writing efficiency deteriorates due to Pole erasure
Solution Approach 1:
The patent applies dynamics by making the magnetization direction of the main magnetic pole switchable between parallel and perpendicular states. A magnetization switching unit is introduced that can rotate the magnetization of the main magnetic pole based on recording conditions, allowing the system to adapt between longitudinal and perpendicular recording modes dynamically, thus resolving the contradiction between signal stability and writing efficiency
Solution Approach 2:
The patent changes the magnetization direction parameter of the main magnetic pole from fixed to variable. By controlling the magnetization orientation (parallel or perpendicular to the medium surface) through the magnetization switching unit, the system can optimize performance for different recording scenarios, improving both signal stability and writing efficiency as needed
2Productivity
If the magnetization of the main magnetic pole is directed perpendicular to the recording medium surface, then writing efficiency is improved, but Pole erasure increases
Solution Approach 1:
The magnetization switching unit enables dynamic control of the main magnetic pole's magnetization direction. During normal writing operations, magnetization can be oriented perpendicular to enhance writing efficiency, while during operations prone to Pole erasure, the magnetization can be switched to parallel orientation, thus dynamically preventing harmful effects while maintaining productivity
Solution Approach 2:
The magnetization switching unit provides preliminary anti-action by preemptively switching the magnetization direction to parallel before Pole erasure can occur. This preventive switching blocks the harmful effect of Pole erasure before it manifests, allowing the system to maintain high writing efficiency without suffering from erasure problems
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively enhances writing efficiency while minimizing Pole erasure, allowing for stable signal maintenance without reducing writing performance.
Implementation Method 1
a heater for heating at least the main magnetic pole so that a magnetic interaction between the main magnetic pole and the main magnetic pole-magnetization fixing portion can be decreased
Implementation Method 2
A coil 13 is wound around the main magnetic pole 11 so as to generate a writing magnetic field. In writing, a writing current is flowed in the coil 13 to generate the current magnetic field at the main magnetic pole
Implementation Method 3
The writing magnetic field is applied to the magnetic recording medium 20 so as to penetrate through the magnetic recording medium 20
Implementation Method 4
main magnetic pole-magnetization fixing portions 24 made of antiferromagnetic material are disposed at both sides of the main magnetic pole 11 respectively so as to generate the magnetization toward the track width direction of the magnetic recording medium in the main magnetic pole 11 through the exchange coupling between the main magnetic pole 11 and the fixing portions 24
Data Source
AI summary
An example magnetic recording head includes a main magnetic pole containing a ferromagnetic layer and a main magnetic pole-magnetization fixing portion containing an anti-ferromagnetic layer in contact with at least one side surface of the main magnetic pole. A heater for the main magnetic pole is configured so as to include an oxide layer with a metal path therein embedded in or provided in the vicinity of the main magnetic pole-magnetization fixing portion and a pair of electrodes, provided in the vicinity of the oxide layer, for flowing a current parallel to a surface of a recording medium through the metal path. A magnetic field generator generates a magnetic field so as to direct a magnetization of the main magnetic pole in one direction.