Magnetic disk system having a magnetoresistive head provided therein

In a magnetic disk system, a magnetic head comprising:

• a magnetic film having two ends and magnetoresistance effect and disposed substantially parallel to the direction of the width of a track of a magnetic recording medium;
• at least one pair of current supplying electrodes disposed to be in contact with both ends said magnetic film in the direction of the width of said track;
• and
• at least one signal detecting electrode to be in contact with said magnetic film disposed between said current supplying electrodes and having a width narrower than that of said current supplying electrodes;
• means for obtaining a first reproduced output between said signal detecting electrode and one of said current supplying electrodes;
• means for obtaining a second reproduced output between said signal detecting electrode and the other one of said current supplying electrodes;
• means for calculating a difference between said first reproduced output and said second reproduced output;
• and
• an insulating film is interposed between said signal detecting electrode and said magnetic film, and only that part of said signal detecting electrode which is adjacent to said recording medium is in contact with said magnetic film.

In a magnetic disk system, a magnetic head comprising:

• an elongate magnetic film having a magnetoresistance effect and disposed with its elongate direction substantially parallel to the direction of the width of a track of a magnetic recording medium;
• at least one pair of current supplying electrodes, each one of the pair of current supplying electrodes disposed near and electrically contacting a different elongate end of the magnetic film;
• and
• a signal detecting electrode electrically contacting the magnetic film between the current supplying electrodes and having a width that is narrower than a width of said current supplying electrodes;
• means for obtaining a first reproduced output between said signal detecting electrode and one of said current supplying electrodes;
• means for obtaining a second reproduced output between said signal detecting electrode and the other one of said current supplying electrodes;
• means for calculating a difference between said first reproduced output and said second reproduced output;
• and
• an insulating film interposed between part of said signal detecting electrode and said magnetic film, a part of said signal detecting electrode which is nearer to the downstream end of said MR film, relative to a running direction of said recording medium, being in contact with said magnetic film.