Magnetic Disk Device Polarity Adjustment for High-Frequency Patterns
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic disk devices face challenges in maintaining high recording quality when writing data with high-frequency patterns due to differences in data pattern polarity, leading to potential read errors and bit error rates.
Innovation Solution
A magnetic disk device and write processing method that detect the difference in loss percentages of high-frequency patterns of different polarities and adjust the data patterns accordingly to optimize the recording quality by adjusting the occurrence frequency of data patterns of specific polarities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If data including high-frequency patterns is written to the magnetic disk, then the physical length of data to be written is reduced, but the recording quality of the written data is lowered
Solution Approach 1:
The patent changes the polarity parameter of high-frequency data patterns dynamically. When a high-frequency pattern is detected, the system inverts its polarity based on the previous pattern's polarity, ensuring alternating polarities that optimize magnetic recording characteristics and maintain recording quality during high-speed writing operations
Solution Approach 2:
The patent introduces dynamic polarity adjustment mechanism that adapts the data pattern polarity in real-time during the writing process. The system monitors the previous data pattern and dynamically inverts the polarity of subsequent high-frequency patterns, making the writing process adaptive rather than static
2Productivity
If data patterns of 1T bits are written to the disk, then the physical length of data is shortened, but the bit error rate increases due to asymmetry in loss percentages of different polarities
Solution Approach 1:
The patent deliberately introduces controlled asymmetry in the form of polarity inversion for high-frequency patterns. By inverting the polarity of alternating high-frequency patterns, the system compensates for the inherent asymmetry in magnetic recording loss, balancing the recording characteristics and reducing bit error rates
Solution Approach 2:
The patent applies preliminary anti-action by pre-inverting the polarity of high-frequency patterns before writing them to the disk. This anticipatory polarity inversion counteracts the expected asymmetric loss that would otherwise occur during recording, preventing bit errors before they happen
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 improves the bit error rate and recording quality by balancing the occurrence frequencies of data patterns of positive and negative polarities, reducing the asymmetry in bit error rates and enhancing the overall data writing process.
Implementation Method 1
a head configured to write data to the disk
Data Source
AI summary
According to one embodiment, a magnetic disk device including a disk, a head configured to write write data to the disk, and a controller configured to write first data including a high-frequency pattern, detect, from a reproduced waveform obtained by reading the written first data, a difference between a first percentage by which high-frequency patterns of a first polarity are lost and a second percentage by which high-frequency patterns of a second polarity obtained by reversing the first polarity are lost, and adjust a high-frequency pattern of the first polarity of the write data or a high-frequency pattern of the second polarity of the write data on the basis of the difference.