Resolution considerations in rear-surface magnetic printing

One form of magnetography that has received considerable attention uses rear-surface recording on conventional magnetic tape. This method has advantages as regards process simplicity, but has major resolution limitations. We investigated these limitations and find that high quality printing resolution is achievable. Adjacent-spot interactions are reduced by minimizing spacing of the head relative to the active tape surface, and selecting optimum tape parameters. Head-field profiles are calculated using a modified Karlqvist approximation, and verified by measurements on large-scale models. Also the recorded image´s properties are studied as a function of head to magnetic layer coating separation at various gap lengths. We find that the main resolution limitation is spreading of the head writing field, causing effective adjacent spot interactions in the direction of magnetization, strongly influenced by tape parameters