A novel dual screen projection system using balance-type micromirror with piezoelectric actuator

This paper presents an innovative dual screen projection system (DSPS) to solve the problem of existing micro-projectors only being able to project a single small picture. Therefore, this study designed a balanced double micro-mirror synchronous scanning mechanism using LIGA-like technology for dual screen projection. The DSPS was composed of balance-type dual micro-mirrors as fast axis, an eccentric slow axis mechanism, and slender piezoelectric actuators. For the balance-type dual projection structure, two micro-mirrors are connected using a Y-shape beam, so that both micro-mirrors can synchronous scanning form motion behaviors approximate to a balance. The experiments demonstrated when a voltage of 10V_pp was applied, the scanning angle of the slow axis and the fast axis were respectively 5.6° and 6.8°, and their driving frequencies were respectively 7.168kHz and 9.126kHz. The DSPS were applied a voltage of 10V_ac matched with a DC voltage of 1V and integrated the fast axis mold and slow axis mold, so as to simultaneously project dual rectangular and dual round pictures. The study achieves the function of a synchronous display of two images. Therefore, this DSPS is well suited for application to portable projection equipment in the future.