Sub-pixel Image Registration Techniques for High Precision Micro Motor Runout Measurement

The purpose of this paper is to demonstrate a method for runout measurement of hard disk drive spindle motor. This paper first reviews different technologies used for obtaining high precision micro motor runout measurement, and compares the limitation of several existed nanometer level measurement instruments that are used to measure spindle motor runout. An instrument based on optical vision sub-pixel image registration technology is thus developed for realizing high measuring accuracy, easy operation and low cost micro motor test. The experimental studies on different type micro motor are also presented