Abstract A magnetic transducer for read-write applications is disclosed in which the magnetic circuit comprises a stack of laminations of generally ''''C'''' shape having a read-write winding inductively associated therewith. The read-write gap is provided by the opposed ends of the stacked laminations, and the laminations are of two different types; that is, they have different magnetic characteristics and are preferably of different materials. The outer laminations have relatively low initial permeability relative to the remaining laminations so that they are ineffective during the read operation but have sufficiently low coercive force so that they are magnetized during the write operation. The inner laminations of the stack have relatively high initial permeability so that they are magnetized during the read operation. In this way, the effective height of the stack and, accordingly, the width of the read-write gap is narrower during the reading operation than it is during the writing operation, being essentially equal to the total stack for writing and essentially equal to the inner laminations for reading.
In a read-write head, a magnetic core comprising a stack of laminations providing a magnetic circuit with an uninterrupted read-write gap of substantially uniform width in one leg of said core defined by opposed ends of the laminations in said one leg, conductor means inductively coupled to said core, said head being adapted for mounting in operative relation to a recording medium with the leg including said gap in closely spaced relation to the medium with the flux fringing the lower edge of said gap penetrating said medium and with the edge of said laminations facing said medium, the outside laminations of said stack being constructed of a material having low initial permeability relative to the remaining laminations so that the outside laminations are ineffective during the read operation and have a sufficiently low coercive force so that they are magnetized during the writing operation, the inner laminations of the core being constructed of material having relatively high initial permeability so that they are magnetized during the read operation, thus providing a read-write gap having an effective width equal to the full stack dimension during the write operation and a width equal to the stack of inner laminations for the read operation.
Claim 2
Dependent Claim
202 words
In a read-write head, a magnetic core comprising a stack of laminations providing a magnetic circuit with an uninterrupted read-write gap of substantially uniform width in one leg of said core defined by opposed ends of the laminations in said one leg, conductor means inductively coupled to said core, said head being adapted for mounting in operative relation to a recording medium with the leg including said gap in closely spaced relation to the medium with the flux fringing the lower edge of said gap penetrating said medium and with the edge of said laminations facing said medium, the outside laminations of said stack being constructed of a material having low initial permeability relative to the remaining laminations so that the outside laminations are ineffective during the read operation and have a sufficiently low coercive force so that they are magnetized during the writing operation, the inner laminations of the core being constructed of material having relatively high initial permeability so that they are magnetized during the read operation, thus providing a read-write gap having an effective width equal to the full stack dimension during the write operation and a width equal to the stack of inner laminations for the read operation.
Claim 3
Dependent Claim
29 words
The read-write head of claim 1 in which the outer or write laminations are oriented with the easy axis of magnetization parallel to the length of the magnetic circuit.