This article discusses the current status and achievements of R2R technology for large area nano-scaled optical devices developed at MSL/ITRI. Firstly, a single layer of nanostructure on polymer film is designed for anti-reflection purpose by finite difference time domain (FDTD) method in the visible light spectrum. The conical array with around 1 aspect ratio, like moth-eye shape and showing superior performance in the optical simulation, has been adapted for the R2R experiments. The development of R2R process includes roller machine design and fabrication, roller mold design and making, development of rolling imprint process, characterization of rolled devices. In this study, large area (200mm *200mm) Ni template was fabricated with DUV exposure, followed by dry etching and electroforming process, respectively. Then, the template was bonded on the roller mold with magnetic film to make nanostructure roller mold. With the delicate nanostructure roller mold, systematic experiments have been conducted on the home-made roller machine with various parameters, such as linear speed, dose rate, and material modifications. The duplicated nanostructure films show very good optical quality of anti-reflection (AR < 1%) and are in good agreement with the theoretical predictions. Besides, the duration of the roller mold has been highly promoted to hundreds of imprint in the UV embossing process.