Imaging Effects in Anisotropic Contact Duplication

Abstract

The contact duplication efficiency is calculated for the anhysteretic printing of a prerecorded master tape onto an anisotropic copy tape in the presence of a permeable transfer head. Complete solutions are given for the cases of the transfer head either on the copy or master tape side. At short wavelengths, where transfer head imaging is ineffective, the solutions are identical and yield, for the special case of an isotropic copy tape, a copy magnetization which is an anhysterized image of the master. At long wavelengths, with a large permeability, the efficiency in the first case varies linearly with wave number (6 dB per octave); it depends only on the vertical component of the anhysteretic susceptibility, since the transfer head images out the longitudinal component of the field from the master tape. In the second case, both components of the master tape fields are imaged out which results in a quadratic wave number variation (12 dB per octave).