Reduction of Magnetic Interference in a Recording Head
Original Publication Date: 1985-Nov-01
Included in the Prior Art Database: 2005-Feb-19
The figures show a shield for a magnetic recording head which reduces the susceptibility of the head to external magnetic fields, improving the signal-to-noise ratio of the magnetic recording system. Fig. 1 illustrates the coupling mechanism of external magnetic fields to an unshielded recording head. The head 4 is made of magnetic material and so provides a low reluctance path to external magnetic fields in the region near the head. Therefore, the fields tend to concentrate in the head. Any fields which pass through all or part of the pickup coil 5 induce a noise voltage which interferes with the desired readback signal. To keep the external magnetic fields from passing through the coil, a shield 6, made of conductive material, is wrapped around the coil and back-bar 7, as shown in Figs. 2 and 3.