Magnetically Shielded Twin-Track Magnetic Read Head Structure
Original Publication Date: 1983-Dec-01
Included in the Prior Art Database: 2005-Feb-08
This disclosure describes improved shielding for a magnetic read head used in a twin-track recording/read-back technique. Prior shielded magnetic read head structures are known; for example, U. S. Patent 3,921,217 shows one such example. Several problems exist with the prior devices, however, in that an isolated one bit may not be sensed. Other difficulties exist as well and will be described in further detail below. Fig. 1 illustrates a simplified cross-sectional view of a typical thin film read head using a magnetoresistive (MR) sensor element. A magnetic medium 1 magnetized either longitudinally, as shown by the magnetic vectors, or vertically moves with a velocity V towards the left in Fig. 1. At some height h above its surface, the demagnetizing field present at the magnetic transition areas in the tape die out to zero.