| 摘要 |
<p>1,111,709. Magnetic data storage apparatus. INTERNATIONAL BUSINESS MACHINES CORPORATION. 30 March, 1967 [4 May, 1966], No. 14460/67. Heading H3B. Creeping in a coupled-film store is reduced by applying a hard-direction bias to the storage elements. Magnetic films 14 are provided on each side of bit - sense lines 12, storage regions being defined by the intersections of lines 12 with word lines 10. The easy axes of the films are transverse to the longitudinal axes of the bit lines 12. It is stated that creeping occurs when intermittent fields having a magnitude up to about 30% of the anisotropy field of the films are applied to a storage region. To avoid creeping, bias field 26 is applied along the hard axis of the films, the field having a magnitude of between 50% and 100% of the anisotropy field. The bias field preferably acts in the same direction as the word field 20, so that the magnitude of the latter required for writing and reading is reduced. Magnetic material may be provided on the sides of the bit lines to completely close the easy-axis flux. Keeper films 24 may be provided for closing the hard-axis flux of each storage element. A keeper film in the form of a single magnetic sheet overlying the storage plane is also referred to. The bias field may be provided by a solenoid or a Helmholtz coil arrangement, or each keeper film 24 may be made of anisotropic high-remanence material with an easy axis transverse to its length. These keeper films are permanently magnetized in the direction of the word field to provide the necessary bias field.</p> |
