| 摘要 |
1,186,310. Selective printing. STANDARD TELEPHONES & CABLES Ltd. 29 Nov., 1968, No. 56768/68. Heading B6F. [Also in Division G5] A magnetic recording head for electromagnetic printing and/or display apparatus comprises an insulating sheet 1 on which a plurality of wavy lines 2 of conducting material are formed, an array of holes 3 in rows and columns each row being associated with a wavy line 2 such that alternate holes in said row are located on opposite sides of the associated wavy line, the sheet 1 being folded concertina-wise along lines 13 so that the holes in each row are registered with one another coaxially and the wavy line forms a helical winding around the cylindrical hole so formed, a magnetic core member being passed through each such cylindrical hole and the assembly of core members and folded sheet being encapsulated in a body of non-magnetic material such that an end of each of the core members is flush with a recording surface of the body. The insulating sheet may be of thermoplastic material, and may be coated with conducting material such as copper, which is etched away to form the wavy lines 2. The holes may be formed by first etching the conductive material and then using the conductive material as a mask to etch the thermoplastic sheet. Alternatively, the holes may be punched, drilled or burnt, e.g. by a laser. The wavy lines may be printed on the sheet 1. The conductive wavy lines may be formed on both sides of the sheet or on one side only, in which case they may be coated with an insulating layer. The sheet 1 may be wider at its ends 4, 8, to provide more room for lead-in contacts and circuitry. The layer with end widenings may be formed from a rectangular sheet with a trapezium of material removed. The non-magnetic potting material may be epoxy resin. The cores may comprise straight rods (14), Fig. 2, not shown, which may be coupled to a further magnetic body (20), Fig. 4, not shown, or may comprise horseshoe shaped pieces (18), Fig. 3, not shown, the sheet 1 then being folded along alternate lines 13 only. |
