Development Of Auto-alignment Laminating Machine For Touch Panel

Capacitive touch panel is the mainstream of the market, while the manufacturing process is very complex, especially the test of the display and touch function, so the requirement of the test on the touch panel and FPCB(Flexible Printed Circuit board) is high demanded. In this paper, the touch panel and FPCB alignment is based on machine vision. With the help of machine vision in touch panel and FPCB laminating process, a new system is designed, while the traditional manual mode was abandoned, With UVW platform(a 3-DOF platform), image process and automation technology, touch panel and FPCB automatic alignment machine is designed.Main work of the thesis includes the following parts:(1) Based on the laminating principle of touch screen and FPCB, we design the automatic alignment machine. The Design of the new laminating module changed the original alignment mode from once open loop to to the multiple closed loop. Through analyzing the characteristics of the touch screen and FPCB image, design of visual module made two cameras gather the image of the adjustment Mark. A simple platform design made the whole system run more efficiently.(2) In this paper, by establishing the model of this platform, the formula of the platform is obtained. Based on the platform model, a new calibration method is proposed in this paper. This method is able to combine the pixel coordinate and the platform coordinate, and the camera calibration also can verify the motion precision of the platform, and two cameras can be associated with the same pixel coordinates. At the same time, the strategy of alignment is developed by using two cameras to guide the sale platform for alignment.(3) Based on image characteristics of touch panel and FPCB, we designed a solution that detected different feature in different color. We also designed an edge algorithm in this research, which can extract the linear edge. Verification test showed that the algorithm was fast, repeatable and flexible.(4) By establishing the test platform of touch screen and FPCB automatic alignment machine, the test proves that the proposed algorithm can accurate identification Mark fastly and accurately. And the results of the adjustment strategy test proved that the strategy is feasible.