Diamond micro-scraping for the fabrication of polygonal Fresnel lens structure array on roller molds

In roll-to-roll (R2R) manufacturing of optical films, machining the microstructure on the roller mold is a crucial step. However, a trimmed radial Fresnel lens structure is discontinuous, and direct diamond cutting the trimmed radial Fresnel lens structure array on the surface of a roller mold was considered infeasible. Hence, a new machining method, diamond micro-scraping (DMS), combined with the polygonal Fresnel lens structure array characteristics, provides a possible solution for machining the Fresnel lens structure array on the roller molds. Tool path planning and simulation analysis were based on the layout of the polygonal Fresnel structure array. In this paper, a polygonal Fresnel lens structure array is processed directly on the periphery roller surface with a diamond tool. The machining performance of DMS was evaluated by studying the influence of different materials and machining parameters on the machined surface quality. The proposed method guides the design and precision manufacturing of the Fresnel lens structure array on precision rollers.