Design of a Piezoelectric-Driven Tilt Mirror for a Fast Laser Scanner

Abstract

Recently, laser scanners have been used for laser processing such as cutting, welding, and grooving, especially in the automotive industry. The laser scanners need a high-speed driving to minimize cracks caused by thermal shock of brittle materials. Therefore, a novel laser processing system that is composed of a laser source and a piezoelectric-driven tilt mirror to control the reflection angle of the laser beam, and a stage equipped with the tilt mirror has been investigated. In this study, a piezoelectric-driven tilt mirror is designed and analyzed for scanning performance to achieve a beam spot of 30 µm, a pattern width of 1 mm, an overlap ratio of 70% of the circle area, and a scanning speed of 1 m/s. Then, structural analysis of the tilt mirror with three piezoelectric actuators is performed to determine the maximum reflection angle and resonance frequency. Finally, a prototype tilt mirror is fabricated and its basic characteristics are experimentally investigated and discussed.