Fabrication and characterization of controllable micro wavy pattern on cylindrical surface using ultra-precision diamond turning system

The study investigated the fabrication and characterization of a controllable wavy patterned mold using an ultra-precision diamond machining system. The design method of cutting tool path for controllable wavy pattern on a cylindrical surface, considering the tool radius, was discussed. The target was designed as periodic sine wave and random amplitude wave to develop components for next-generation displays. The effectiveness of the designed tool path was confirmed by comparing the machined surface profiles. The compensated tool path was able to reduce the machined shape error by approximately 50%. The optical characteristics of the machined pattern were analyzed by the luminance distribution of the transmitted laser through the replicated optical film for each machined tool path. When the compensated tool path was applied, a symmetrical distribution line with two spots of higher luminance concentration was observed. Finally, an investigation was conducted on the machinability of controllable randomness for next-generation display components, and their optical characteristics were evaluated.