Data Storage Head Fly Height Control via Pre-Bias Current
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing data storage devices face challenges in maintaining optimal head fly height and data quality during write operations, particularly when encountering defective data sectors, which can lead to data corruption and reduced component lifespan.
Innovation Solution
The implementation of a pre-bias current with a lower transition frequency and increased amplitude during a pre-bias interval, applied to the write coil while the head is over a defective data sector, to achieve a stable fly height before writing to a target sector, along with ramping down the current to degauss the coil and prevent data corruption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the head flies too low over the disk surface, then data quality improves, but the risk of head-disk contact and component failure increases
Solution Approach 1:
The patent applies pre-bias current to the write coil before the head reaches the target data sector, allowing the fly height to stabilize in advance. This preliminary action ensures optimal head-disk spacing is achieved before writing begins, improving data quality without requiring the head to maintain excessively low flight throughout the entire operation, thereby reducing component stress and failure risk.
2Manufacturing precision
If the fly height is maintained at optimal levels, then data quality improves, but write component stress increases
Solution Approach 1:
By applying pre-bias current before the write operation, the system achieves optimal fly height stabilization in advance. This allows the head to maintain proper spacing only when needed for data writing, rather than continuously, thereby reducing cumulative stress on write components while ensuring data quality during critical write operations.
Solution Approach 2:
The patent implements periodic application of pre-bias current during fly height transitions, specifically before entering and after leaving defect sectors. This periodic action maintains optimal fly height during critical write operations while allowing relaxation during non-critical periods, reducing overall component stress while preserving data quality.
3Manufacturing precision
If pre-bias current is applied to stabilize fly height, then head positioning consistency improves, but energy consumption increases
Solution Approach 1:
The pre-bias current is applied only during specific transition periods before and after defect sectors, not continuously throughout operation. This targeted preliminary action stabilizes fly height only when necessary for maintaining positioning consistency during critical write operations, minimizing unnecessary energy consumption while achieving the required positioning precision.
Solution Approach 2:
The system employs periodic pre-bias current application during fly height transitions rather than continuous application. This periodic approach maintains head positioning consistency during critical operations while significantly reducing overall energy consumption compared to continuous pre-biasing, by activating the pre-bias current only when fly height stabilization is required.
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 ensures consistent head positioning, minimizes stress on write components, and maintains data integrity by stabilizing the head fly height and reducing the risk of data corruption, thereby extending the lifespan of write components and improving data quality.
Implementation Method 1
Data is typically written to the disk by modulating a write current in an inductive coil (write coil) to record magnetic transitions onto the disk surface
Implementation Method 2
Heat assisted magnetic recording (HAMR) is a recent development that improves the quality of written data by heating the disk surface during write operations to decrease the coercivity of the magnetic medium
Implementation Method 3
Microwave assisted magnetic recording (MAMR) is also a recent development that improves the quality of written data by using a spin torque oscillator (STO) to apply a high frequency auxiliary magnetic field to the media close to the resonant frequency of the magnetic grains
Data Source
AI summary
A data storage device is disclosed comprising a head actuated over a magnetic media. A write operation is executed to a first data sector by writing to at least part of a defective data sector preceding the first data sector in order to achieve a target fly height of the head prior to writing to the first data sector.