Magnetic Disk Thermal-Assist Writing With Parallel Position Learning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In magnetic disk devices using thermal assist methods, there is a delay in stabilizing data writing quality, and the process of learning and writing the correction amount for positional deviations during manufacturing is inefficient, leading to potential issues with bit error rates.
Innovation Solution
A magnetic disk device that performs data writing using a thermal assist method, where the magnetic head reads positional information in parallel with heating the disk to learn and write a correction amount for positional deviations, allowing for simultaneous detection of defective portions and improving the quality of the correction amount by forming a cured product on the head during this process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermal assist method is used for data writing, then data writing capability is improved, but time to stabilize data writing quality increases
Solution Approach 1:
The patent applies preliminary action by forming a cured product on the magnetic head before actual data writing operations. This cured product is created during a learning period where the head flies over the disk without writing data, allowing the coating to stabilize. This preliminary preparation ensures that when data writing begins, the head is already in optimal condition, eliminating the stabilization delay that would otherwise occur during initial writing operations.
2Measurement precision
If learning process is performed separately from data writing, then learning accuracy is improved, but manufacturing efficiency deteriorates
Solution Approach 1:
The patent merges the learning process with the data writing process by performing both operations simultaneously during manufacturing. The magnetic head learns the correction amounts for positional deviations while writing data patterns to the disk. This combination allows the learning accuracy to be maintained while significantly improving manufacturing efficiency, as two previously separate processes are now executed in parallel, reducing total manufacturing time.
3Reliability
If cured product is formed during learning phase, then writing quality is improved, but head wear may occur
Solution Approach 1:
The patent applies partial action by forming the cured product on only the trailing surface of the magnetic head during the learning phase, rather than the entire head surface. This selective coating formation improves writing quality where needed while minimizing potential wear issues. The cured product is formed in a controlled manner during the learning period, providing the necessary protection and stability without excessive material deposition that could cause problems.
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 enhances the quality of data writing by reducing bit error rates and ensuring high accuracy from the start of writing, by maintaining consistent flying height and preventing wear of the cured product formed during the learning phase.
Implementation Method 1
supplying assist power to the assist mechanism to heat a learning target portion of the magnetic disk
Data Source
AI summary
A magnetic disk device includes a magnetic disk to which positional information for each track is written, an assist mechanism that heats the magnetic disk, a magnetic head that performs data reading and data writing on the magnetic disk, and a controller that controls the magnetic disk device. The controller is configured to cause the magnetic head to read the positional information written to the magnetic disk to learn a correction amount of a positional deviation generated in synchronization with rotation of the magnetic disk, in parallel with reading the positional information, cause, while supplying assist power to the assist mechanism to heat a learning target portion of the magnetic disk, the magnetic head to write a data pattern used for detection of a defective portion of the magnetic disk, and while supplying the assist power to the assist mechanism to heat a writing target portion of the correction amount of the magnetic disk, cause the magnetic head to write the learned correction amount to the magnetic disk.