TMR Head Resistance Drop Evaluation for Magnetic Tape Quality
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge is to develop a method for pre-shipment inspection of magnetic tapes that ensures the quality of magnetic tapes for use in magnetic tape devices, particularly when using Tunnel Magnetoresistive (TMR) heads, which are prone to significant decreases in electric resistance due to their unique structure and sliding contact with the magnetic tape, leading to errors in signal reproduction and head tracking.
Innovation Solution
An evaluation method involving the use of a TMR head to read the servo pattern on a magnetic tape, measuring the electric resistance of the TMR head after reading, and determining the tape's quality based on the degree of resistance decrease from a reference value, ensuring the magnetic tape does not cause a significant drop in electric resistance, thereby preventing errors in signal reproduction and head tracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If TMR head is used to read servo pattern on magnetic tape, then sensitivity of signal reading is improved, but electric resistance of TMR head decreases significantly due to sliding contact
Solution Approach 1:
The patent applies preliminary action by conducting a pre-shipment inspection that reads the servo pattern on the magnetic tape before the TMR head is permanently installed in the magnetic tape device. This preliminary reading operation allows evaluation of whether the magnetic tape will cause significant resistance decrease in the TMR head during actual use, enabling selection of compatible tape-head combinations before deployment.
Solution Approach 2:
The patent implements feedback by measuring the electric resistance of the TMR head before and after reading the servo pattern, then using this resistance change information to determine whether the magnetic tape is suitable for use. The resistance measurement provides feedback about the interaction between the specific magnetic tape and TMR head, allowing quality determination based on actual performance impact.
2Quantity of substance
If recording density is increased by narrowing data track width, then capacity of magnetic tape is improved, but head tracking accuracy deteriorates
Solution Approach 1:
The patent applies preliminary action by performing head tracking servo using the servo pattern read from the magnetic tape before final quality determination. This preliminary head tracking operation allows evaluation of whether the narrowed data tracks can be properly followed by the magnetic head, enabling assessment of head tracking accuracy in the context of high-density recording before the tape is approved for use.
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 effectively determines the quality of magnetic tapes by assessing the electric resistance decrease, ensuring they can be used without causing significant drops in TMR head performance, thus stabilizing signal reproduction and head tracking accuracy.
Implementation Method 1
a magnetic head including a tunnel magnetoresistance effect type element as a servo pattern reading element
Implementation Method 2
measuring electric resistance of the tunnel magnetoresistance effect type element after the reading; and determining quality of the magnetic tape by using a degree of a decrease in the measured electric resistance
Data Source
AI summary
Provided are an evaluation method of a magnetic tape, in which the magnetic tape which is an evaluation target includes a magnetic layer including a servo pattern, the method including: reading the servo pattern by a magnetic head including a tunnel magnetoresistance effect type element as a servo pattern reading element; measuring electric resistance of the tunnel magnetoresistance effect type element after the reading; and determining quality of the magnetic tape by using a degree of a decrease in the measured electric resistance from a reference value as an index, and a manufacturing method of a magnetic tape including: evaluating the magnetic tape including a servo pattern in a magnetic layer by the evaluation method.