Two gap read/write head assembly

DETAILED DESCRIPTION S OF PREFERRED EMBODIMENTS Referring now to FIGS.
1 and 2, there is shown a two gap read/write head assembly known in the prior art and comprising the head assembly that includes a housing 1 of magnetic materials such as permalloy which serves as a magnetic shield, a write pole-piece 2 and a read pole-piece 3 which are contained in housing 1 and each respectively have gaps 21 and 31.
The gaps 21 and 31 are exposed relative to the housing 1 to be engaged with the tape medium and a magnetic shield plate 4 made of a plurality of permalloy plates and Be-Cu plates mounted in the housing 1 is provided as a magnetic shield between the read and the write pole-pieces 2 and 3.
A non-magnetic material 5 such as Be-Cu is utilized to prevent a magnetic coupling between pole-pieces 2 and 3 and housing 1.
It is a matter of common knowledge that a write coil and a read coil are wound, respectively, to the write pole-piece 2 and the read pole-piece 3, although these coils are not shown in FIGS.
1 and 2.
When a pulse train representing the information signal A as illustrated in FIG.
10A is applied to the write coil wound to the write pole-piece 2 to record information represented by the information signal A onto the moving magnetic tape medium (not shown), instantaneously the information signal A is read or reproduced by the read pole-piece 3, from the read coil of which is obtained the signal as shown by D in FIG.
10D.
The read signal D includes the feedthrough signal shown at B in FIG.
10B and the reproduced signal C shown in FIG.
10C.
In comparison with the reproduced signal C of 35 mV, when the information signal A is 30 V, the feedthrough signal of 6 mV cannot be ignored, particularly when considering the existence of variation of the read signal level.
The important feature of this invention is the provision of means for cancelling the feedthrough signal developed in these two gap read/write head assemblies.
Referring now to FIGS.
3, 4 and 5, there is shown a two gap read/write head assembly which is similar to the prior art assembly shown in FIGS