Magnetic sensing apparatus having a central core with wire therethrough

Abstract

A magnetic head sensing apparatus includes a first, second and third magnetic core of a soft magnetic film formed by a thin film forming method. One end of the first and second magnetic core face a magnetic recording medium and are disposed with a predetermined distance therebetween field. The third magnetic core is disposed between the first and second magnetic cores. A conductive coil is wound around the third magnetic core. A conductive wire passes through the third magnetic core and is insulated therefrom. A DC-biased high-frequency constant current flows through the conductive wire to reproduce information recorded on the magnetic recording medium. Also, a recording signal is applied to the conductive coil sense the magnetic field.

We claim:  
     
       1. A magnetic recording and reproducing  sensing apparatus comprising: 
       a magnetic head comprising: 
       a first magnetic core and a second magnetic core each including a soft magnetic film,one end of each core being for facing a magnetic recording medium and disposed with a predetermined distance therebetween,  
       a third magnetic core including a soft magnetic film, disposed between said first and second magnetic cores,and magnetically connected to the other ends of said first and second magnetic cores,  
       a conductive wire passing through said third magnetic core while being insulated from said third magnetic core, said conductive wire flowing a DC-biased high-frequency constant current to reproduce information recorded in said magnetic recording medium , and  
       a winding of conductor wound around said third magnetic core, said winding of conductor applied with a signal to be recorded in said magnetic recording medium, and 
       carrier signal application means for applying the DC-biased high-frequency constant current across said conductive wire.  
     
     
       2. A magnetic recording and reproducing  sensing apparatus in accordance with  claim 1 , wherein said third magnetic core comprises a first soft magnetic film and a second soft magnetic film, and the area on an end surface of each of said first and second soft magnetic films for facing said  a magnetic recording medium  field is smaller than the area on each respective opposite end surface thereof. 
     
     
       3. A magnetic recording and reproducing  sensing apparatus in accordance with  claim 1 , wherein the thickness of said third magnetic core is smaller than the thicknesses of said first magnetic core and said second magnetic core. 
     
     
       4. A magnetic recording and reproducing  sensing apparatus in accordance with  claim 1 , further comprising: 
       a high-frequency voltage detection means for detecting a high-frequency voltage, the high-frequency voltage changing depending on a magnetic field defined by a bias magnetic field, caused by said DC-biased high-frequency constant current superimposed on an external magnetic field, caused by a magnetic recording medium,  and  
       an  AM demodulation means for demodulating said detected high-frequency voltage.