;This study investigated concave micro lens films, a key component in localized 2D/3D switchable display lenticular lens technology, using the Roll-to-Roll technology in conjunction with a Taguchi Method experimental design to develop orthogonal table-planned experiment groups. Each group was subjected to forming machine for rolling and solidifying of microstructures. Geometric shapes of end products were measured and experimental data were evaluated and analyzed. Quality indicators were 2D/3D switchable display performance and the para bonding disposition of the panel. To satisfy the quality indicators, the size of the end products must be highly accurate. Thus, the nominal-the-best (NTB) quality characteristic was adopted to measure the accuracy of four critical sizes in order to gain results that were consistent or close to specifications.
Experiments were divided into two stages. In the first stage, four sets of control factors and three standards were selected. Factor A was formation speed, factor B was UV power, factor C was winding/rewinding tension, and factor D was front/rear roller pressure. Interaction among the factors was not considered. The L9 orthogonal table-planned experiment groups were analyzed to obtain the ideal process parameter combination (A3, B2, C1, D1) and the descending order of factor influence (D, B, C, A). In the second stage, the original process parameter combination (A2, B2, C2, D2) was compared with the ideal process parameter combination (A3, B2, C1, D1). The obtained experimental values used to verify the SNR prediction were highly accurate.
Findings indicated that the ideal process parameter combination of the four critical sizes was increased compared with the original process combination. On average, the concave height increased by 0.04 μm, the concave interval increased by 0.02 μm, the concave radius curvature increased by 0.5 μm, and the concave thickness increased by 0.5 μm. Moreover, the four critical sizes produced by the ideal process parameter combination achieved better consistency with specifications relative to the original process combination. Thus, the ideal combination satisfied the NTB quality characteristic and approximated the target values.