Eraser for magnetic recoder and playback with spiral track - moves magnetic head back to starting point by retracing its motion over spiral track in reverse direction

摘要

On depressing the eraser button when the magnetic head has moved on the magnetic surface of a magnetic sheet from the periphery thereof to its center, while following a spiral track, and the recording or reproducing operation has been completed, the magnetic head is moved back to its starting position by retracing the spiral track in the reverse direction. An erasing current is passed to the magnetic head when it retraces the spiral track in the reverse direction so as to erase the recordings. The same magnetic head is used for erasing as for recording and reproduction, which then performs a demagnetising function.