Dual Write Head Helical Coils for Magnetic Recording Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional magnetic recording heads in HDDs face a design tradeoff between achieving high areal recording density, which is the product of linear density and track density, as optimizing for one aspect, such as bit per inch (BPI), negatively impacts the other, like tracks per inch (TPI), due to magnetic field leakage and data rate dependencies.
Innovation Solution
A dual-write head design where the first write head is optimized for higher BPI with a stronger write field and the second write head is optimized for higher TPI with a higher data rate, using coils wrapped around yokes of different lengths and materials, allowing for simultaneous improvement in both capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the write head uses a large number of coil turns to deliver a large amount of magnetic field to achieve high BPI, then the write field strength is improved, but magnetic field leakage to adjacent tracks increases causing adjacent track interference and reducing TPI capability
Solution Approach 1:
The patent divides a single write head into two separate write heads: a first write head with a longer yoke and more coil turns optimized for high BPI, and a second write head with a shorter yoke and fewer coil turns optimized for high TPI. This segmentation allows each write head to specialize in one function without the tradeoff that plagues a single write head design.
2Speed
If the write head uses a short yoke with a small number of coil turns to achieve high data rate capability, then the data rate is improved and side field leakage is reduced benefiting TPI, but the write field strength is insufficient for high BPI
Solution Approach 1:
The patent creates two specialized write heads: the first write head with longer yoke and more coil turns for strong write field (high BPI), and the second write head with shorter yoke and fewer coil turns for high data rate. This segmentation resolves the contradiction by allowing each head to be optimized for its specific function.
3Quantity of substance
If a single write head is designed to achieve high areal density, then one aspect (BPI or TPI) is improved, but the other aspect deteriorates due to the design tradeoff
Solution Approach 1:
The patent segments the write function into two separate write heads, each optimized for different aspects of areal density. The first write head targets high BPI while the second write head targets high TPI, together achieving high areal density without the compromise of a single write head design.
Solution Approach 2:
The dual write head assembly provides multi-functionality by combining two specialized write heads in one assembly, enabling the system to achieve both high BPI and high TPI capabilities simultaneously, which a single write head cannot accomplish.
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
This dual-write head design enhances areal density capacity, BPI, and TPI, enabling efficient and reliable data writing and reading without compromising signal-to-noise ratio, outperforming conventional single-write head systems.
Implementation Method 1
A first coil is wrapped around the first yoke, and a second coil is wrapped around the second yoke
Data Source
AI summary
The present disclosure generally relates to a magnetic media drive employing a magnetic recording head. The magnetic recording head comprises a first write head disposed adjacent to a second write head. The first write head comprises a first main pole coupled to a first yoke having a first length. The second write head comprises a second main pole coupled to a second yoke having a second length that is less than the first length of the first yoke. A first coil is wrapped around the first yoke, and a second coil is wrapped around the second yoke. The first coil is wrapped around the first yoke a greater number of times than the second coil is wrapped around the second yoke. Both the first and second coils comprise first portions comprised of a first material and second portions comprised of a second material different than the first material.