Magneto-optical sound recording system - opposed magnetic domains along spiral track detected by polarised light

摘要

An optical scanning system with a control system for the recording and reproduction especially of audio signals, with an optically transparent disc of magnetic material, which can support mobile opposed cylindrical zones under the influence of an applied field. A continuous especially spiral track is generated on the surface of the disc; polarised light can be transmitted through the plate and through an analyser to respond to the presence of the opposed cylindrical magnetic zones.