Three-Dimensional, Real-Time, and High-Accuracy Inline Monitoring System for Roll to Roll Manufacturing

A non-contact, real-time, high-accuracy, low-cost, broad-range, and full-field 3D shape measurement technique is presented. The technique is based on a generalized fringe projection profilometry approach, and it employs random phase shifting, double- frequency projection fringes, ultrafast direct phase unwrapping, and inverse self-calibration schemes to perform 3D shape determinations with enhanced accuracies in a real-time manner. The measurement accuracy can reach 1/10000 of the field of view or higher, and the acquisition speed is capable of achieving 5 to 30 3D views per second. Experiments have been conducted to verify the validity of the proposed technique. Due to its superior capability, the real-time, high-accuracy 3D shape measurement technique is very suitable for inline monitoring the flexible electronics products during roll to roll manufacturing, and it can also serve as an experimental tool to investigate the mechanical/thermal reliability issues involved in flexible electronics design and optimization analysis.