Towards one trillion positions

How accurately can you determine positions using a non-expensive imaging system? We demonstrate a system, that has the potential to achieve position detections over a large measurement field (200 x 200 mm) for one million times one million 2D positions. Non-expensive telecentric imaging of the large object field is achieved using a large diffractive front element in combination with two small off-the-shelf lenses. The position measurement itself is considerably improved using a simple replication technique: the point to be measured is replicated N-times and the centers of gravity of the N points are averaged. By this approach discretization errors and camera noise are reduced by the square root of the number of points. We describe the system, discuss the error model and show experimental results for the DOE-based telecentric imaging and the position detection sensing.