Alignment turning system for precision lens cells

Abstract

This research increases the ability and value of a traditional vertical lathe and applies to manufacture a precise lens cell for the optical industry. The optical performance is limited by the residual centration error and position accuracy of conventional assembly methods. Recently, the development of a poker-chip assembly system with high-precision lens barrels has overcome these limitations and provided a solution for ultra-high-performance optical systems. To develop a high-precision lens cell by using poker-chip assembly, an alignment turning system (ATS), is developed based on a vertical lathe and equipped with tactile and optical measurement modules. Inside the ATS, the building-in the vibration/temperature monitoring sensors, which help to self-monitoring and network communication with the intelligent manufacturing techniques, to understand and master the reliability and efficiency of ATS. This system can manufacture precise lens cells, applied for optical metrology, high numerical aperture objective lenses, and lithography projection lenses. This paper describes the design and development of the ATS and its capabilities. The ATS is composed of measurement, alignment, and turning modules. After the ATS completes the measurement, alignment, and turning processes, the centration error of a lens cell, which is 200 mm in diameter, can be controlled to within 10 arcsec. Here, a lens cell with three subcells was assembled through the poker-chip method; each subcell was measured and then it underwent alignment and turning processes. The lens assembly test was performed five times by three technicians, and the average transmission centration error of the assembly lens was 12.45 arcsec. The results demonstrate that the ATS can achieve considerable assembly efficiency for high-precision optical systems.