公开(公告)号：BR8605250A

公开(公告)日：1987-07-28

申请号：BR8605250

申请日：1986-10-28

Applicant: IBM

Inventor： POHL WOLFGANG DIETER ,  GIMZEWSKI JAMES KAZIMIERZ ,  MURALT PAUL RENE

IPC: G11B5/60 ,  G11B21/21 ,  G11B21/12

Abstract: The method involves the steps of lowering the magnetic head (8) to within aerodynamic distance from the surface (16) of a moving recording medium, enforced further lowering of the head (8) until a tunnel current occurs across the gap between head (8) and surface (16), and maintaining said tunnel current constant by using the deviations of the current from a predetermined value (which corresponds to a certain flying height).The apparatus comprises a tunnel electrode (9) forming an integral part of the head assembly which is attached to a distance control mechanism (5) permitting the positioning of the head assembly with a one-nanometer accuracy. The tunnel electrode (9) has a very slightly beveled shoulder (45, 47) ensuring early detection of asperities approaching the head while sitting on the surface (16) of the moving recording medium (3). Grada­tion of the potential between tunnel electrode (9) and surface (16) of the recording medium (3) is used to enhance the response to asperities.