Rotating head assembly for video tape recorder - uses layers of strong and weak magnetic effect to modify reluctance and direct field through tape

摘要

A sub layer (3) of weak magnetic effect is located under a layer (2) with a strong magnetic effect. This reduces the reluctance between the surface of the latter layer and the magnetic tape (4) and the rear magnetic pole (5). The perpend-icular head has its main pole (1) consisting of a thin magnetic film on a non magnetic support adjacent to the tape. This is perpendicular to the tape on which it records as it rotates. The flux generated by a coil (6) into which the signal current is injected is concentrated by the main pole and orientated by the strong magnetic layer. The weak magnetic layer diffuses it over a large area. The reluctance in the space separating the weak magnetic layer of the rear pole is weakened before the reluctance separating the main pole from the same layer so that the field travels through the tape to record the signal.