Substrate disc positioning method for laser beam recorder

摘要

The positioning method provides accurate centring of the substrate disc (7) relative to a turntable (3) which is rotated at high revs by an electric motor drive spindle (2), by detecting the imbalance as a linear displacement of a linear guide (4), supporting the drive spindle and the turntable. A processor calculates the amplitude and angular position of the turntable eccentricity from the detected displacement, to allow the position of the substrate disc on the turntable to be corrected when the drive spindle is brought to a stop.