The invention relates to a device for the storage of digital information in the form of magnetic domains in magnetizable layer under the control of a bias field transverse to the layer, further comprising driving means in the form of at least one current conductor which has at least a partially meander-like shape and can be driven by a periodical electric current, for producing a track along the meander-shaped part of it for the magnetic domains. Such a device is known from the U.S. Pat. No. 4,157,591 (see for example FIG. 8). The known device has a mixed drive mechanism, i.e. is driven partially by means of a periodical electric current in a meander-shaped conductor, and by a magnetic field rotating in the plane of the plate of magnetizable material, namely along a track that is determined by a series of I-, T-, and Y-shaped elements of permalloy. As described in the above literature reference, both the drive mechanisms have their advantages. The drive with a rotating field is very attractive for low bit frequencies. For high bit frequencies the drive with a rotating magnetic field is no longer possible, and a current-controlled drive has been to be used. There is a disadvantage here, however, that the dissipation is then also high. This applies very much to completely serially organized memories with a large storage capacity that work completely with current drive. The state of the art relevant to this invention is exemplified in a paper by E. Dekker, et al, "Combination of Field and Current Access Magnetic Bubble Circuits", IEEE Transactions-Magnetics, MAG-13, No. 5 (September 1977), pages 1261-1263.
USPTO Backgrounds
USPTO Backgrounds