Process and apparatus for producing contoured molded mirrors with

Abstract

Production of precision reflective mirror surfaces on low cost, lightweight molded plastic substrates (10). The process involves making a master pattern (12) having a precision machined contoured surface (13) corresponding to the precision mirror surface desired on the plastic substrate. A release layer (14) and a reflective layer (17) are applied to the master pattern and then transferred to the molded plastic substrate (10), with a curable replication layer (18) therebetween preferably comprising a filler-reinforced polymer composition which is compatible with the polymeric substrate and has a low coefficient of thermal expansion (CTE) which closely matches the CTE of the substrate. The replication layer (20) is cured to replicate the precision of the surface (13) of the master pattern (12), which can be reused to produce a multiplicity of high precision molded plastic mirrors (21). In order to achieve improved accuracy and lower cost, the molded substrate tooling is adjusted (corrected) to account for differences in dimensions and/or surface contour. This more accurate substrate allows for a thinner replication layer which is less sensitive to error during curing and when the part is subjected to environmental conditions such as temperature variation. In the preferred case superior accuracy is achieved by the combined replication and correction process.