Boundary displacement magnetic recording apparatus

Claim 1

IN A VARIABLE AREA MAGNETIC RECORDING HEAD FOR PRODUCING ON A LONGITUDINALLY MOVING ELONGATED MAGNETIZABLE RECORDING MEDIUM A PERMANENT MAGNETIC RECORD OF AN ELECTRICAL SIGNAL IN WHICH THE HEIGHT OF SAID RECORD TRANSVERSELY OF SAID MEDIUM VARIES IN CORRESPONDENCE WITH VARIATIONS OF THE INSTANTANEOUS AMPLITUDE OF SAID SIGNAL, THE COMBINATION OF: AN ELECTROMAGNET FOR PRODUCING A MAGNETOMOTIVE FORCE CORRESPONDING TO SAID SIGNAL; A MAGNETIC POLE STRUCTURE OF SUBSTANTIAL LENGTH DISPOSED TRANSVERSELY OF SAID RECORDING MEDIUM WITH ONE SURFACE IN CONTACT WITH SAID MEDIUM, SAID POLE STRUCTURE HAVING A RELATIVELY HIGH RELUCTANCE FROM END TO END AND COMPRISING A PLURALITY OF THIN SEPARATE MAGNETIC MEMBERS DISPOSED IN SIDE BY SIDE RELATION WITH THEIR THICKNESS DIMENSION PARALLEL TO THE LENGTH OF SAID STRUCTURE, SAID MAGNETIC MEMBERS BEING HELD IN SPACED RELATION TO EACH OTHER BY NON-MAGNETIC SPACER MEMBERS INTERPOSED BETWEEN ADJACENT MAGNETIC MEMBERS; AND MAGNETIC CONDUCTOR MEANS OF LOW RELUCTANCE CONNECTED BETWEEN ONE END OF SAID ELECTROMAGNET AND ONE END OF SAID POLE STRUCTURE TO MAGNETIZE SAID END OF SAID POLE STRUCTURE IN ACCORDANCE WITH SAID MAGNETOMOTIVE FORCE PRODUCED BY SAID ELECTROMAGNET, EACH OF SAID MAGNETIC MEMBERS BEING MAGNETIZED IN AN AMOUNT DEPENDENT UPON THE MAGNETOMOTIVE FORCE PRODUCED BY SAID ELECTROMAGNET AND THE DISTANCE OF SAID MAGNETIC MEMBER FROM SAID ONE END OF SAID POLE STRUCTURE, WHEREBY SAID RECORDING MEDIUM IS MAGNETIZED ALONG THE LENGTH OF SAID POLE STRUCTURE TO A VARYING DEGREE DEPENDENT UPON THE AMPLITUDE OF SAID SIGNAL AND THE DISTANCE FROM SAID ONE END OF SAID POLE STRUCTURE.