THERMOREMANENT MAGNETIC IMAGING METHOD

摘要

An energy efficient thermoremanent magnetic imaging method and apparatus comprising a moving magnetic recording medium which is passed through a nip formed by a thermal printhead and a pressure roller, so that the magnetizable surface of the recording medium is in pressure contact with the heating elements of the thermal printhead. The recording medium is pre-magnetized prior to entry in the nip and passed through a magnetic field of lower strength and opposite polarity at the nip. Small areas or pixels of the pre-magnetized recording medium are heated by the thermal printhead in image configuration and allowed to cool in the presence of the magnetic field at the nip. The magnetic poles of the imagewise pixels are switched, forming fringe fields between the pixels and pre-magnetized background areas. The pixels with the switched magnetic poles are spaced from each other to prevent the fringe fields from forming around the periphery of clusters of pixels and collapsing inbetween some or all of the pixels making up the cluster.