| abstract |
An improved twin track read/write head structure that is differential in its response, thereby eliminating common mode noise signals is described. It also has a low electrical offset, increased linearity and reduction or elimination of any bias fields interfering with the magnetic recording medium. The structure utilizes a dual coupled film magneto resistive sensor bridging the legs of two magnetically permeable coupling members so that the dual magnetic sensors are in a series magnetic circuit with the coupling members. The dual coupled film magnetic sensors are connected together in a center tapped arrangement and are oppositely magnetically biased. Opposing voltages changes occur when the pair are subjected to a magnetic flux field passing serially through them. This produces a differential output signal that rejects unwanted common mode noise of all types. In addition, during read back when the sensors are biased by a magnetic flux field into their sensitive range, the balanced differential structure of the head presents equal magneto motive forces at both ends of the sensor where they connect to the flux coupling legs. As a consequence, there is no net flux available at the other ends of the coupling legs and no flux is coupled to the media. |