6 degree-of-freedom (DOF) motion measuring apparatus using multidirectional reflector, and swing arm type optical system using the 6-DOF motion measuring apparatus to measure 6-DOF motion of HDD Slider

摘要

A 6 degree-of-freedom (DOF) motion measuring apparatus using a multidirectional reflector, and a swing arm type optical system using the 6-DOF motion measuring apparatus to measure the 6-DOF motion of a slider in a hard disc drive (HDD) are provided. The 6-DOF motion measuring apparatus includes: a multidirectional reflector having at least three reflecting sides by which the laser beam is slit and reflected in three directions, the multidirectional reflector being provided to the object whose motion is to be measured; three position-sensitive detectors for receiving three sub-laser beams reflected from the multidirectional reflector; and a controller for calculating the 6-DOF motion of the multidirectional reflector using the intensity distributions of the three sub-laser beams received by the three position sensitive detectors assuming that the laser beam before reflection has a Gaussian intensity distribution. The 6-DOF motion of an object can be easily and precisely measured using the multidirectional reflector having three reflecting sides. The 6-DOF motion measuring apparatus can be applied to measure the displacement of a small object moving at high speed.