Präzises Positionieren mittels intelligenter Schlagwerke

When assembling micro-optical instruments, a goal is the positioning of the elements with permissible deviations in the sub-micrometer-range and angle deviations smaller than a few seconds. In manufacturing a well-known fact is, that the attitude of an object can be exactly changed by applying momentum to its end. This idea was developed further by Fraunhofer Institute, Jena into an effective and universal principle of adjustment for miniaturized components in precision engineering and in microoptics. In contrast to conventional adjustment methods, the component to be adjusted is immobilized with the final prestressing force before the adjustment process starts. Then, specific momentums generated by an electromagnetic striking mechanism are transmitted to the immobilized component. The result of the impact against the object are stepped movements in form of lateral or fine angular motions caused by the momentum transfer and by the stick-slip-effect. Depending on the mechanical arrangem ent minimum incremental motions better than 150 nm or 0.3 arcsec are achieved. Different prototypes of intelligent striking mechanisms have been investigated and optimized. The attitude of the object to be adjusted is determined by a measuring system and fed back into a computer (numerical control system). The combination of eight strike magnets and a PC-based algorithm allow fast and exact positioning of the components fibre/fibre or fibre/opto-electronic sensor. The described prototypes enable angular adjustments of components (for example mirror mount) with accuracy better than 1,0 arc sec, lateral alignments with accuracy better than 300 nm and inexpensive solutions to adjustment problems. In the range of adjustment of 0.5mm the adjustment process can be made in several seconds