Magnetic Head Sub-Track Magnetization Control for Ternary Recording
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Solution Overview
Problem
Magnetic recording devices face challenges in achieving stable high-density recording due to issues with magnetization control at sub-track end portions, leading to erroneous recording and reproduction of ternary values, particularly when using two sub-tracks.
Innovation Solution
The magnetic recording and reproducing device employs a magnetic head with a recording unit and reproducing unit, utilizing a configuration with two sub-tracks per track, where the reproducing width is set to be not less than 1.2 times the side gap between the magnetic pole and side shield, and the saturation magnetization of the side shield is aligned with the write shield, to stabilize magnetization control and reduce reproduction noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high-density recording is implemented using two sub-tracks, then recording capacity is improved, but magnetization control at sub-track end portions becomes unstable
Solution Approach 1:
The patent applies local quality by setting different magnetization states for different regions within a track. Specifically, the first sub-track and second sub-track are assigned different magnetization values (first magnetization and second magnetization) to encode ternary information. This local differentiation allows high-density recording while maintaining control stability through defined magnetic states at sub-track boundaries.
Solution Approach 2:
The patent utilizes parameter changes by varying the magnetization state (a physical parameter) of the magnetic recording medium to represent different data values. By controlling the magnetization to be in a first state, second state, or intermediate state, the system achieves ternary recording. The magnetization control is stabilized by managing transitions between these states at sub-track end portions.
2Loss of information
If ternary values are recorded in sub-tracks, then information density is improved, but reproduction noise increases
Solution Approach 1:
The patent reduces reproduction noise by applying local quality control at sub-track end portions. Different magnetization values are assigned to the first and second sub-tracks, creating distinct magnetic signatures that reduce interference and noise during reproduction. This localized magnetization differentiation maintains high information density while minimizing harmful noise effects.
3Device complexity
If magnetization control is relaxed for simplicity, then device complexity is reduced, but recording precision deteriorates
Solution Approach 1:
The patent achieves precise magnetization control by utilizing parameter changes in the magnetic recording medium. By controlling the magnetization to transition between defined states (first state, second state, intermediate state), the system achieves ternary recording precision without requiring overly complex control mechanisms. The precision is maintained through managed transitions between these magnetic states.
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 configuration enables stable magnetic recording and reproduction of ternary values by minimizing reproduction noise and ensuring accurate control of magnetization at sub-track end portions, thereby enhancing the reliability of high-density data storage.
Implementation Method 1
The magnetic recording medium includes a first track including a first sub-track extending along a first direction, and a second sub-track extending along the first direction... One of the first magnetic recording components has a first magnetization. The one of the second magnetic recording components has a second magnetization.
Implementation Method 2
The reproducing unit reproduces the information recorded in the magnetic recording medium... The reproducing unit includes a reproducing element having a reproducing width along the second direction.
Data Source
AI summary
According to one embodiment, a magnetic recording and reproducing device includes a magnetic recording medium and a magnetic head. The magnetic recording medium includes a first track including a first sub-track extending along a first direction, and a second sub-track extending along the first direction. The second sub-track is arranged with the first sub-track in a second direction intersecting the first direction. The magnetic head includes a recording unit and a reproducing unit. The recording unit records information in the magnetic recording medium. The reproducing unit reproduces the information recorded in the magnetic recording medium. The recording unit includes a magnetic pole, a write shield separated from the magnetic pole in the first direction, and a side shield separated from the magnetic pole in the second direction. The reproducing unit includes a reproducing element having a reproducing width along the second direction.