Magnetic Disk Shingle Write Frequency Control
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Solution Overview
Problem
The shingle write system improves track recording density but falls short in enhancing linear recording density, necessitating further advancements to meet increasing storage demands.
Innovation Solution
A magnetic disk apparatus that employs a recording head with a controller managing overlapping writes on adjacent tracks, varying writing frequencies to optimize recording density, with a higher frequency on wider tracks to enhance Bit Per Inch (BPI) while maintaining a sufficient Signal-to-Noise (S/N) ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the recording head is narrowed to reduce track width, then track recording density is improved, but recording magnetic field density lowers and S/N ratio cannot be secured
Solution Approach 1:
The patent divides the writing process into multiple passes, where information is written on tracks in a partially overlapping manner across multiple writing operations. This segmentation allows each track to be written with sufficient magnetic field density while achieving high overall track recording density through the overlapping arrangement of multiple tracks.
Solution Approach 2:
The patent transitions from writing information sequentially on single tracks to writing on multiple tracks simultaneously in an overlapping pattern. This dimensional change in the writing approach allows the system to achieve high track recording density without compromising the magnetic field density on individual tracks, thereby maintaining S/N ratio.
2Manufacturing precision
If the shingle write system is applied to improve track recording density, then track width can be reduced, but linear recording density improvement is insufficient
Solution Approach 1:
The patent varies the writing frequency dynamically during the writing process, using a first writing frequency for tracks where information is last written and a second writing frequency for other tracks. This parameter change allows optimization of both track recording density and linear recording density by adjusting the writing frequency according to the specific track and writing stage.
3Productivity
If higher writing frequency is applied to increase linear recording density, then Bit Per Inch improves, but S/N ratio may be compromised
Solution Approach 1:
The patent applies different writing frequencies to different tracks based on their specific characteristics and position. Tracks where information is last written receive a first writing frequency, while other tracks receive a second writing frequency. This local quality approach ensures that each track receives the optimal writing frequency to maintain both linear recording density and S/N ratio according to its specific requirements.
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 approach effectively increases linear recording density and overall storage capacity by prioritizing higher writing frequencies on wider tracks, securing an S/N ratio and improving recording density without compromising signal quality.
Implementation Method 1
a perpendicular magnetic recording type in which a recording layer is magnetized in a perpendicular direction to a plane of a magnetic disk is adopted
Data Source
AI summary
An object of the present invention is to further improve a recording density in a magnetic disk apparatus using a shingle write system.In a magnetic disk apparatus including a magnetic disk, a recording head that writes information on the magnetic disk, and a controller that controls a writing operation of the recording head to the magnetic disk, the controller controls the writing operation such that the recording head writes information on a region including a target track and a portion of track adjacent thereto in an overlapping manner while position-shifting in a radial direction of the magnetic disk and a first writing frequency to a track on which information is last written is higher than a second writing frequency to another track.