UVW Platform Automatic Alignment System Development For Touch Screen

In the LCD flat panel touch display industry,a series of equipment are arranged for the pre-processing and post-processing processes of production,such as evaporation,photolithography,printing,inspection,connection,bonding and packaging,etc.The laminating process is to seamlessly glue the glass cover,display panel,and touch sensor together with transparent glue material.Alignment bonding firstly needs to align the marks of the upper substrate and the lower substrate of the screen,and then apply pressure to bond,and finally achieve tight bonding through light curing glue.The traditional manual alignment is to adjust the movement mechanism to achieve alignment by observing the misalignment of the mark by the human eye.With the development of touch screen products,higher requirements are put forward for the accuracy and speed of touch screen bonding.It is difficult to overcome the problem of insufficient accuracy and efficiency,whether it is by manual bonding or by tooling and fixture bonding.Compared with the traditional lamination technology,the visionguided alignment technology can provide higher lamination accuracy and production efficiency,can ensure stable product quality,and help reduce defective products.Another advantage of machine vision alignment technology is that it can adapt to automated production lines and give full play to its advantages of accurate positioning and fast speed.This thesis studies the automatic alignment system of the touch screen and analyzes the needs of the alignment system.The UVW motion platform composed of parallel mechanisms with high motion repeatability and high rigidity is selected as the alignment execution device,and the motion control system of the UVW motion platform is designed.In the research process,the parallel structure of the UVW motion platform was analyzed,and the positive and negative kinematics solutions were obtained,which provided a basis for the subsequent motion control system.The key issues of camera calibration,image matching,Mark point positioning in visual automatic alignment are studied,and a visual solution suitable for automatic alignment system is proposed.According to the design plan,an experimental verification platform was built to verify the camera calibration result,image matching algorithm,and alignment effect.The experimental results show that the design scheme of the automatic alignment system can meet the design requirements.