Two-dimensional Laser Scanner with Low Mechanical Cross Coupling based on Piezoelectric Actuators

Traditional two-dimensional laser scanners usually employ two-degree-of-freedom flexible hinges. However, these flexible hinges suffer from mechanical cross coupling between axes, which will reduce the scanning accuracy and stability. To overcome the above disadvantages, a compact novel laser scanner based on piezoelectric actuators is presented. The scanner uses only three one-dimensional flexible hinges to achieve two-axis feature. The mechanical structure and principle are detailed. Then the capabilities of the scanner are tested by a performance test system. The test results show that the scanner has a tilt angle of 43.19 mrad for X-axis with resonance frequency at 149.21 Hz and 2.41 mrad for Y-axis with resonance frequency at 232.59 Hz. Its scanning nonlinearity is reduced from 3% to 0.5% for X-axis and from 6% to 1% after compensation. The test results and the actual scanning images prove the low mechanical cross