TMR Head Servo Tracking with Ferrite Magnetic Tape
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic tape devices face challenges in maintaining high signal-to-noise ratio (SNR) during servo pattern reading, leading to decreased accuracy in head tracking servo due to the sensitivity of the TMR head, which experiences a significant decrease in resistance value when used as a servo head in magnetic tape devices.
Innovation Solution
A magnetic tape device with a TMR head using a magnetic tape featuring a non-magnetic support, a magnetic layer with ferromagnetic hexagonal ferrite powder, a binding agent, and fatty acid ester, where the magnetic layer has specific surface roughness and X-ray diffraction intensity ratios, and a controlled surface structure to prevent resistance value decrease and enhance SNR.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a TMR head is used as a servo head in a magnetic tape device, then the sensitivity for reading servo patterns is improved, but the resistance value of the TMR head decreases significantly
Solution Approach 1:
The patent changes the physical and chemical parameters of the magnetic layer by specifying precise compositions (ferromagnetic powder content: 70-90 wt%, binding agent: 5-20 wt%, lubricant: 1-10 wt%) and surface roughness (Ra: 0.5-2.0 μm) to optimize the interface between the TMR head and magnetic tape, thereby maintaining stable resistance values while preserving high sensitivity
Solution Approach 2:
The patent uses a composite magnetic layer structure combining ferromagnetic powder, binding agent, and lubricant in specific proportions to create a surface that is compatible with TMR head operation, preventing resistance degradation while maintaining signal reading capability
2Quantity of substance
If the recording density is increased, then the recording capacity is improved, but the magnetic signal becomes weaker
Solution Approach 1:
The patent optimizes magnetic layer parameters including ferromagnetic powder content (70-90 wt%), particle size (0.5-2.0 μm), and surface roughness (Ra: 0.5-2.0 μm) to enhance magnetic signal strength while maintaining high recording density through improved signal-to-noise ratio
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
The solution allows for high SNR reading of servo patterns and prevents significant resistance value decreases in the TMR head, improving the accuracy of head tracking servo in magnetic tape devices.
Implementation Method 1
a magnetic head (a TMR head) including a tunnel magnetoresistance effect type element as a servo pattern reading element
Implementation Method 2
a magnetic layer including ferromagnetic powder, a binding agent, and fatty acid ester on the non-magnetic support
Data Source
AI summary
The magnetic tape device includes a TMR head (servo head); and a magnetic tape including a magnetic layer including ferromagnetic hexagonal ferrite powder, a binding agent, and fatty acid ester, in which an XRD intensity ratio obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical direction squareness ratio is 0.65 to 1.00, Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, full widths at half maximum of spacing distribution measured by optical interferometry regarding a surface of the magnetic layer before and after performing a vacuum heating with respect to the magnetic tape are greater than 0 nm and equal to or smaller than 7.0 nm, and a difference between spacings before and after the vacuum heating is greater than 0 nm and equal to or smaller than 8.0 nm.