The effect of selective assembly on tolerance desensitization

Abstract

Tolerancing has long been identified as a crucial part in the development of optical systems. It aims at finding the best balance between quality and cost as tolerances closely tie together manufacturing expenses and performance. Tolerance effects have been included into the optimization function (merit function) by some lens designers to find insensitive designs1-5 and frequently compensators are employed to further improve the performance of assembled lenses. Compensators are limited to a small number of system parameters, but selective assembly of components can extend the number of parameters available for compensation. It can be employed to reduce tolerance effects of disturbed parameters by finding the best matches out of a set of components. In this work we discuss how desensitization and selective assembly can be combined to loosen tolerances and increase as-built performance. The investigations concentrate on tolerance insensitive design forms under the presence of selective assembly compensators. In contrast to desensitizing a given lens or introducing new design means we focus on introducing new assembly strategies into the design procedure and investigate how using selective assembly as a compensator while desensitizing the remaining design parameters can lead to even less sensitive designs.