| 摘要 |
<p>716,898. Magnetic recording and reproducing apparatus. ARMOUR RESEARCH FOUNDATION OF ILLINOIS INSTITUTE OF TECHNOLOGY. Feb. 19, 1952, No. 4358/52. Class 40 (2). A magnetic transducing head is provided with means for producing a secondary magnetic field to produce changes in the intensity and configuration of the primary field in the region of one of the pole tips as compared with that of the other tip. In the embodiments described, the secondary magnetic field is obtained by the use of a second core member 15 such as shown in Fig. 1. A coil 26 on the second core member may be fed with the same audio currents as fed to the main coils 24, 25, and the polarity so arranged that the resultant field is strengthened in the region of the trailing polepiece 13, Fig. 5, after leaving which the field rapidly decreases. Both core members may be energised by signal currents having high frequency bias currents superimposed on them. A second winding 39, Fig. 13, may be provided on the secondary core member 15 and connected in such a manner as to produce an intense audio field on one side of the transducing gap and an intense bias field on the other side of the said gap. In another embodiment, Figs. 14 and 15, the high frequency bias is supplied to both core portions through separate windings 42, 43. The high frequency bias supplied to these windings is displaced 90 degrees in phase with respect to each other to produce a rotating high frequency field. In yet another embodiment, Fig. 10, an auxiliary yoke 37 is provided having a coil 38 which has a sufficient number of turns to provide an intense magnetic field for erazing purposes. A modification of this embodiment, Fig. 11 (not shown), dispenses with the secondary yoke 34, the auxiliary yoke 37 serving to provide a sufficient cross field in the region of the gap to provide the desired high frequency bias.</p> |
