METHOD FOR CONTROLLING DRIVE SHAFT IN SUPER-PRECISION SHAPE MEASUREMENT DEVICE OF NORMAL VECTOR TRACKING TYPE

摘要

PROBLEM TO BE SOLVED: To provide a method for controlling a drive shaft in a super-precision shape measurement device of normal vector tracking type deriving a surface shape of a measurement object from a measurement point coordinate and a measurement value of a normal vector, shortening measurement time at each measurement point by devising a control method of each shaft, and increasing the speed of the surface shape measurement of the measurement object.;SOLUTION: The device includes two sets of two-axis goniometers and a one-axis rectilinear movement stage changing the distance between the rotation centers thereof. One set of goniometers constitute a sample system 2, and a measurement object 1 is held by a moving part thereof. The other set of goniometers constitute an optical system 3, and a light source and a photodetector D are provided at a moving part thereof. From among the two sets of two-axis goniometers and the one-axis rectilinear movement stage, one set of two-axis goniometers and the one-axis rectilinear movement stage perform full closed feedback control in which an output from the photodetector is directly input to a shaft drive motor, and the rest one set of two-axis goniometers perform semi-closed feedback control.;COPYRIGHT: (C)2010,JPO&INPIT