Writer Structure With Assisted Bias For Perpendicular Recording
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Solution Overview
Problem
In magnetic recording systems, perpendicular recording designs face challenges in maintaining data integrity due to remnant magnetic fields from pole tips, which can cause erasure of bits on the media, and there is a need to improve areal density and prevent extraneous magnetic fields from interfering with recorded transitions.
Innovation Solution
A recording head design incorporating a magnetic pole, a magnetic bias structure, and a spacer between the pole and the bias structure, along with a coil to orient the magnetic field perpendicular to the bearing surface, and an assist mechanism to provide a supplemental magnetic field, which helps in maintaining desired magnetization and preventing unwanted erasure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If perpendicular recording is used to increase areal density, then higher areal density is achieved, but remnant magnetic fields from pole tips cause bit erasure
Solution Approach 1:
The patent extracts and removes the remnant magnetic field from the pole tip by introducing a bias structure that actively cancels or eliminates the unwanted magnetic field, separating the useful writing function from the harmful remnant field effect
Solution Approach 2:
The patent converts the harmful remnant magnetic field into a beneficial effect by using the bias structure to shape and control the magnetic field, transforming the problematic remnant field into a controlled field that assists in maintaining desired magnetization states without causing erasure
2Reliability
If a magnetic bias structure is added to prevent bit erasure, then data integrity is improved, but device complexity increases
Solution Approach 1:
The patent merges the bias structure with the existing pole assembly, integrating multiple functions into a unified structure that reduces overall complexity while maintaining the benefits of both the writing pole and the biasing mechanism
Solution Approach 2:
The patent designs the bias structure to serve multiple functions simultaneously, including providing magnetic bias, shaping the magnetic field, and assisting in maintaining magnetization, thereby reducing the need for separate components and simplifying the overall device
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 maintains desired magnetization of the pole tip even when the writing current is removed, preventing bit erasure and improving the reliability of magnetic transitions by reducing unwanted magnetic interactions, thereby enhancing areal density and data integrity.
Implementation Method 1
an electrical current is caused to flow through the conductive coils to thereby induce a magnetic field to emanate from the top pole
Implementation Method 2
A magnetic flux passes through a hard magnetic layer to a soft under layer in the media and across to the opposing pole. The magnetic flux creates transitions on the media.
Implementation Method 3
Magnetic flux from the surface of the disc causes rotation of the magnetization vector of a sensing layer of the MR sensor, which in turn causes a change in electrical resistivity of the MR sensor
Data Source
AI summary
A recording head for use with a storage medium is provided. The recording head includes a substrate, a magnetic pole, a first magnetic bias structure positioned on a first side of the magnetic pole, and a second magnetic bias structure positioned on a second side of the magnetic pole, Spacer material is positioned between the magnetic pole and the first magnetic bias structure and between the magnetic pole and the second magnetic bias structure.