A magnetic read head with output signal independent of tape speed

Abstract

The paper describes a variable-reluctance magnetic read head, designed for use in digital computer output and editing equipments, which can read digits recorded at normal packing densities over a wide range of tape speeds down to zero. Each head is a “double” head, consisting of a variable reluctance read head and a conventional write head. The centre line separation between the read and write sections is one digit interval; with the 100 digit per inch system used, this separation is 0.010 in. The packing density is a function of the separation between the read and write sections only when the head i used for digit-by-digit checking of a writing operation. Eight such heads are built as one unit having external physical dimensions of 1.5 in. × 1.1 in. × 0.75 in. and can be accommodated across standard one-half inch wide magnetic tape. Attention is drawn to the suitability of the reading head for use in off-line editing equipment where the tape speed can be reduced to correspond with the speed of operation of mechanical teleprinters or typewriters, so simplifying the tape transport mechanism and circuitry.