Reducing field distortion for galvanometer scanning system using a vision system

Laser galvanometer scanning systems are well-established devices for material processing, medical imaging and laser projection. Besides all the advantages of these devices like high resolution, repeatability and processing velocity, they are always affected by field distortions. Different pre-compensating techniques using iterative marking and measuring methods are applied in order to reduce such field distortions and increase in some extends the accuracy of the scanning systems. High-tech devices, temperature control systems and self-adjusting galvanometers are some expensive possibilities for reducing these deviations. This contribution presents a method for reducing field distortions using a coaxially coupled vision device and a self-designed calibration plate; this avoids, among others, the necessity of repetitive marking and measuring phases.