Tandem erasing heads for magnetic tape - are arranged with opposite polarities to ensure erasure of all forms of recordings

摘要

An erasure system for a magnetic tape is effective with any form of recording. Three erasing heads (14, 16, 18) are arranged in succession before the recording/reproduction head, and are simultaneously excited by D.C. The direction of current flow through the erasing heads is such that the magnetic polarities of the fields of the erasing heads alternate. The current through the erasing head most remote from the recording head may be sufficiently great to give effective erasure, the current through the other heads being smaller.