The improvement of plastic aspheric lens for the application of compact camera module

Abstract

The requirement for plastic injection of ultra-high precision optical components is critical. Therefore, the precision of optical components has to meet the optical specification. We compensate the core inserts of aspheric lenses and the refine conditions of optical lens injection to improve the forming precision of optical lenses. The key issues of manufacturing plastic optical lenss are thermal shrinkage of the lenses and the decenter of optical axes for the lens module. In the process of plastic lens injection, the shrinkage of a lens is due to temperature variation of the mold and the lens. Because of this, the shrinkage will cause an asymmetric surface profile. The performance of optical lens modules will be affected by the decenter of the optical axes. According to the research, the performance of aspheric lens injection is based on the mold design. In order to meet the optical design requirements, we study diamond turning tool radius compensation, the coordination origin calibration of diamond tool, and the aspheric parameter modification to improve the precision of aspheric core inserts. At the same time, we decrease the decenter of the mold by modifying the mold's structure. The plastic aspheric lens had been improved and raised the performance of optical lens modules.