Analysis of dynamic deformation in 1-D resonating micromirrors

Abstract

Dynamic deformation is an important characteristic in high frequency resonating microscanners intended for high definition raster scanning display applications. Out-of-plane deformation resulting from high acceleration loads causes beam divergence which will in turn reduce the optical resolution. This paper presents a detailed analysis on the mechanical design aspects contributing to dynamic deformation such as the micromirror layout and the micromirror-spring linkage design. Applicability of the one dimensional plate theory in evaluating micromirror bending due to inertial loads is investigated using finite element analysis. A comparison among a number of layout designs was carried out with the aim of increasing micromirror bending stiffness in a direction parallel to the axis of rotation. Moreover spring-linkage effects were also addressed and significant improvement in the dynamic deformation was achieved by the inclusion of a gimbal structure between the micromirror and the torsional springs.