Nearfield sensing and actuation for multispectral imaging systems

The sharpness of edge transition is one of the major requirements in optical sensing especially in the field of image processing. Therefore a lot of algorithms were assessed in the field of digital photography. In the field of industrial image processing especially multispectral imaging different focus positions are needed to get an optimal focus position for every sampling channel. Therefore a control loop was developed which uses an inductive sensor to measure the actual position of an image sensor. With this information a voice coil were activated to actuate the sensor into the optimal position. For a correct operation a resolution of less than fifty microns have to be reached. The paper presents the construction as well as the electronic and sensor actor design. First evaluations demonstrating a proof of concept and will also discussed in the paper.