Servo Pattern Bit Arrangement for Magnetic Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In bit-patterned magnetic storage media, the magnetization inversion in the servo pattern area leads to reduced track positioning accuracy due to the large dot area and lower coercive force, causing instability and data loss.
Innovation Solution
The arrangement method disperses magnetic dots in the servo pattern area to maintain a small dot area, preventing magnetization inversion by dividing and redistributing data bits using a specific bit map pattern, ensuring consistent coercive force and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the dot area in the servo pattern area is made large to store sufficient address information, then the data length can be increased, but the coercive force lowers and magnetization inversion occurs
Solution Approach 1:
The address information is divided into multiple parts and distributed across multiple dots in the servo pattern area. Each dot stores a portion of the address information, allowing the total data length to be increased without requiring any single dot to become excessively large, thereby maintaining coercive force and preventing magnetization inversion.
Solution Approach 2:
The patent utilizes the radial direction distribution of dots in the servo pattern area to store address information. By arranging dots at different radial positions and using multiple dots along the radial direction, the system can increase data capacity without increasing the area of individual dots, thus maintaining magnetic stability.
2Quantity of substance
If the dot area is made large to increase data capacity, then more information can be stored, but the coercive force decreases causing magnetization inversion
Solution Approach 1:
The address information is segmented into multiple smaller units distributed across multiple dots. This segmentation allows the total information capacity to be increased while keeping each individual dot area small, thereby maintaining high coercive force and preventing magnetization inversion.
Solution Approach 2:
Different regions of the servo pattern area are utilized with different dot arrangements. The patent applies local optimization by distributing information density across the radial direction, ensuring that each local region maintains appropriate dot size for stable magnetization while collectively storing sufficient information.
3Reliability
If the magnetization state of servo pattern area is inverted, then the servo information is destroyed, but this inversion is caused by large dot area and low coercive force
Solution Approach 1:
By segmenting the address information across multiple dots, the patent ensures that no single dot requires excessive area to store the complete address. This distribution maintains small dot areas and high coercive forces, preventing magnetization inversion and preserving servo information integrity.
Solution Approach 2:
The patent employs preliminary actions by carefully designing the dot arrangement and address information distribution before recording. By pre-distributing address information across multiple radial positions and using multiple dots, the system prevents magnetization inversion from occurring in the first place, ensuring reliable servo information storage.
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 method enhances the coercive force and stability of the servo pattern, preventing magnetization inversion and maintaining high track positioning accuracy, thereby ensuring reliable data storage.
Implementation Method 1
In the servo pattern area, all the bit magnetization states are in the same direction, and hence magnetic fluxes generated from adjacent bits strike against each other
Implementation Method 2
When the dot area is small, even a single magnetic domain is magnetically stable by virtue of the high coercive force (Hc)
Data Source
AI summary
According to one embodiment, address information is expanded on a bit map in order to generate original address information which is divided in a direction of the abscissa to form groups. The demodulated values of the original address information are obtained as original intra-group demodulated values. New address information is obtained and an arrangement pattern of bits in the servo area determined based on the new address information on a bit map formed by integrating obtained new address information items of the groups.