Shigeki Murata

Displacement measurement of track on magnetic tape by Fourier transform grid method

The Fourier Transform Moire and Grid Method(FTMGM) is a method for measuring displacement and strain by using Fourier transform of a grating image. In this paper, we will present a new method and a system to analyze displacement distribution of the track, which are signal recorded by a video cassette recorder(VCR) and a digital audio tape recorder(DAT), by using the FTMGM. Using this method, we can obtain a two-dimensional distribution of the displacement amount from linear state of the track recorded on a magnetic tape. Therefore, by using this track displacement information, it is possible to clarify the timewize variation state of the displacement and to remove the factors of worsening the track linearity. It is available for a high density recording on a magnetic tape.

A Development of Analysis Techniques for Displacement of Track Patterns.

We use the Fourier Transform Grid Method as the basis for a new approach to analyzing the displacement distribution of the track on which signals are recorded in magnetic recording systems. It is important to make the track width narrower for high density recording on magnetic tape. However, as the track becomes narrower, track linearity must be improved. To improve track linearity, it is necessary to clarify the displacement distribution of the track accurately. Our new measuring method can obtain a two-dimensional distribution of the displacement accurately and can clarify the relation between the displacement distribution and the factors that deteriorate track linearity.