A novel method to optimize a Galvo-Scanner used in optical imaging systems to minimize the artifacts in the images generated

摘要

Microscopic imaging systems especially high speed functional imaging systems employing Galvo-scanner as a beam steering system generate distorted images. In an attempt to make the fast imaging microscopic systems efficient we conducted an in depth study on the possible causes, reasons and formulated an optimal solution for it. We studied and analyzed the behavior of a Galvo Scanner (GS) at different scan frequencies. A triangular signal is usually employed to drive the GS owing its ability to generate less distorted images. Conventionally, the GS's mirrors move in accordance with the input control signal at low scan frequencies(less than 100 Hz) but as we advance to higher scan frequencies (more than 700Hz), GS fails to obey the input due to the inherent mechanical inertia of the mirrors. This scrambles the distance between the microstructures being imaged, thus leading to distortions in the images obtained. Therefore we propose a novel library of (purposely) distorted ramp signal to deal with this problem. The rationale behind this idea is to provide the GS enough voltage to overcome the inertia so that the resultant movement is a linear ramp. The results obtained showed a significant improvement in the behavior of the scanners in the terms of spectral width of the FWHM of the output signal.