| 摘要 |
1,117,067. Magnetic transducers. NATIONAL CASH REGISTER CO. 25 Oct., 1966 [6 Dec., 1965], No. 47762/66. Heading G5R. The polepieces at least of a magnetic transducer head are produced by depositing magnetic material in recesses formed in a non- magnetic substrate and smoothing the magnetic material defining the polepieces and the adjacent substrate into a common surface. Each head may form part of a multiple read/write lead assembly (Fig. 1, not shown). In one nethod, a glass (or silicon) substrate 25 is etched to form recesses 25a, 25b and 25c (Figs. 2, 13) then apertures 40 (Fig. 15) are formed to define a central core leg. High permeability magnetic material such as ferrite or permalloy is deposited in the recesses and over three sides of the centre leg and unwanted material removed by lapping and/or etching. The gap 19 is defined by portions 35a of the substrate which are bevelled to assist accurate formation of the final gap. The winding 45 is threaded around the centre leg and terminated at posts 15c set into a carrier 10. In one modification, the effective permeability of the head is increased by disposing permalloy strips such as 135 (Fig. 24) over selected parts of the magnetic layer in correspondingly deeper recesses 125b. In a second modification, the apertures 40 are omitted and the winding is formed by depositing conductive strips 55 (Fig. 21) in recess 25c followed by the magnetic layer 35 which is then etched to expose the strip ends, and the winding completed by upper strips or gold wires 65, which may connect the heads to printed or integrated circuitry on the substrate (Fig. 22, not shown). |
