2-Dimensional Optical Scanner Applying Torsional Resonator with 3 Degrees of Freedom

Abstract

A two-dimensional optical scanner suitable for integration in a plane structure has been developed. To make it vibration robust, a torsional vibration system with two degrees of freedom is adopted for the resonator, and the vibration system axis is matched to the center of gravity. Piezoelectric bimorph cells are used as the actuator to excite the torsional vibration. Algorithms of Luh, Walker and Paul, which are usually used for motion analysis of manipulators in robot engineering, were applied for deriving the equations. This optical scanner is capable of optical scanning in two orthogonal directions independently or simultaneously at a scanning angle of ±30 degrees or more. One-dimensional scanning is enabled by driving the bimorph cells with the resonance frequency of either of the two torsional vibrations. Two-dimensional scanning is achieved if the bimorph cells are operated by adding the resonance frequency signals of the two torsional vibrations.