FLOATING VARIANCE MEASURING METHOD OF MAGNETIC HEAD

摘要

PURPOSE:To measure easily the floating vibration characteristics of a magnetic head on the surface of a revolving magnetic disk and to improve the productivity, by irradiating laser beams in division to the back side of the magnetic head as well as to an interference reference reflector and making the reflected light of those beams incident to a photodetector. CONSTITUTION:The laser beam radiated from a laser oscillator 12 is irradiated to the back side of a magnetic head 3 receiving the prescribed vibrations from a vibration generator 10 through a semitransparent mirror 13 and the 1st 1/4lambda deflecting plate 14. Then the reflected measured light is deflected by 90 deg. by the reflector 13 through the plate 14 and made incident to a photodetecting part 17. While a part of the laser beam is deflected by 90 deg. by the reflector 13 and irradiated to an interference reference reflector 16 through the 2nd 1/4lambda deflecting plate 15. Then the reference reflected light is irradiated again to the part 17 through the plate 15 and the reflector 13. In such a constitution, a detection signal processing part 18 detects the floating variance of the head 3 including the revolving deflection of a magnetic disk 1 on the basis of the interference fringes produced by the measured reflected light and the reference reflected light. This ensures the easy measurement of the floating vibration characteristics in a short time and high accuracy.