Dual element magnetoresistive sensing head having in-gap flux guide and flux closure piece with particular connection of magnetoresistive sensing elements to differential amplifier

Claim 1

A read head assembly for sensing signals recorded on a magnetic medium comprising: first and second magnetoresistive sensing elements for receiving current-derived fields that are applied symmetrically and in opposite directions to the sensing elements to bias the sensing elements in opposite directions, each sensing element having first and second ends; first and second magnetic shield members for shielding said sensing elements, said shield members defining a central longitudinal axis, said axis being located substantially centrally between said shield members, said sensing elements being spaced on each side of and equally from said longitudinal axis, the ends of said shield members defining a gap; a single flux closure piece disposed closely adjacent to said first ends of said sensing elements and located on said longitudinal axis and spaced substantially equally from said shield members; an in-gap flux guide disposed along said longitudinal axis and centrally in the gap between said shield members and partially between said sensing elements closely adjacent to said second ends of said sensing elements; and a differential amplifier having a pair of inputs coupled to said sensing elements such that each input of said differential amplifier is supplied by current from each individual sensing element, respectively, for providing common mode rejection of the sensed signal and an improved signal-to-noise ratio.