Magnetic dot matrix printing method and apparatus

A magnetic dot matrix printer for printing a data character text, character-by-character, on a sheet of non-magnetic paper, comprising:

• an elongated strip platen of erasable permanent magnet material;
• means for positioning a sheet of non-magnetic paper on one surface of the platen with the platen extending across the paper in alignment with a portion of the paper comprising a location for a line of text;
• carriage means reciprocally movable along a print path adjacent the platen, from one end of the text-line location to the other and back again;
• magnetic recording head means, mounted on the carriage means and comprising a plurality of electromagnets having magnetizing poles corresponding to a group of character matrix dots disposed in closely spaced proximity to one platen surface, for magnetizing dot-size portions of the platen in accordance with predetermined patterns constituting magnetic images of the characters for a line of text by selective energization of the electromagnets during movement of the carriage;
• magnetic toner dispensing means, mounted on the carriage means, for applying limited quantities of a magnetic toner to the exposed surface of the paper overlying the platen generally concurrently with formation of the aforesaid magnetic images to develop visible images on the paper;
• fixing means for fixing the visible toner images on the paper to complete printing of a line of text;
• and
• magnetic erasing means, mounted on the carriage means, for erasing the magnetic images from the platen in preparation for printing a further line of text.