GB1373119A - Magnetic devices - Google Patents

Abstract

1373119 Magnetic storage arrangements WESTERN ELECTRIC CO Inc 16 Nov 1971 [16 Nov 1970 12 April 1971 29 Oct 1971] 53125/71 Heading H3B [Also in Division B1] A garnet substrate on which a garnet layer is grown by liquid phase epitaxial deposition (see Division B1) is used in magnetic devices in particular in "bubble" devices for switching, memory and logic functions. Such devices are shown in Figs. 1 and 2. Fig. 1 shows an arrangement 10 including a sheet or slice 11 of material in which single wall domains can be moved by bar and T-shaped segments and the reorienting in-plane field rotates clockwise in the plane of sheet 11 as viewed. The reorienting field is represented by block 12 and may comprise mutually orthogonal coil pairs (not shown) driven in quadrature. Only closed "information" loops are shown. The movement of domain patterns simultaneously in all the registers represented by loops is synchronized by the in-plane field source 12. Each rotation of the inplane field advances a next consecutive bit to location 13 in each register. The movement of bits in the vertical channel is synchronized with this movement. In normal operation the horizontal channels are occupied by domain patterns and the vertical channel is unoccupied. For read or write operations the domain pattern is transferred to the vertical loop and the locus of the transfer function is indicated by broken loop T encompassing the vertical channel. Transfer is under the control of a transfer circuit 14 which may include a shift register tracking circuit for controlling the transfer of a selected word from memory. A read or a write operation is responsive to signals under the control of control circuit 16. The termination of either a write or a read operation terminates in the transfer of a pattern of domains to the horizontal channel. Fig. 2 shows a portion of an overlay pattern defining a representative horizontal channel in which a domain is moved. The overlay pattern contains repetitive segments. When the field is initially in an orientation as indicated by arrow H, one cycle of the field comprises four phases which moves a domain consecutively to the positions designated by the encircled numerals 1, 2, 3 and 4. The domain patterns in the channels correspond to the repeat pattern of the overlay. Entire domain patterns representing consecutive binary words accordingly move consecutively to positions 13. A domain in position 4 is accordingly ready to begin its transfer cycle.