FRICTIONAL FORCE MEASURING INSTRUMENT FOR DISK MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To attain the measurement of frictional force with high accuracy and extremely reduced output variance caused by the frictional coefficient and the head touch variance, by applying the force to a magnetic head to prevent the displacement of the head which is produced by the frictional force given from a revolving disk magnetic recording medium. CONSTITUTION:A magnetic disk 1 is revolved and a magnetic head 5 having a contact with the disk 1 tries to have the displacement toward the disk driving direction by the frictional force with the disk 1. Here this displacement of the head 5 is converted into the displacement of a permanent magnet 8 via a post 7 and by the principles of the lever and fulcrum. This displacement of the magnet 8 is measured by a metallic sensor 12 for measurement of displacement in the form of the distance between a metallic sensor 12 fixed at the rear end of the magnetic and the sensor 12. Based on this measurement, the current values to be applied to electromagnets 9 and 10 are obtained. Then the magnet 8 is reset to its original state by the repulsive magnetic fields produced from both magnets 9 and 10 applied with said current. Thus the displacement of the magnet 8 is prevented.