| The conductive rubber keyboard is widely used at present.The keys on the keyboard are connected through the silicone rubber keypads on the flexible circuit board inside the keyboard.The positions of the silicone rubber keypads on the flexible circuit board and the positions of the keys on the keyboard are corresponding one by one.The positioning of the silicone rubber keypads is an important link of the production process of the flexible circuit board.The positioning is achieved by laying the silicone rubber keypads to the location holes on the positioning mode through the vibration of electric motor.During the position,there could produce a series quality problem,such as position leak,excess,inversion and deflection and so on.The current way to detect the keyboard flexible circuit board silicone rubber keypads positioning defects is mainly artificial visual inspection.Artificial visual inspection mainly dependent on the subjective experiences of testing personnel,the accuracy and reliability of artificial visual inspection are low,and it will create higher labor costs.Therefore,it is very important to study the research of an online keyboard flexible circuit board silicone rubber keypads positioning detect detection system with high degree of automation,high precision and high efficiency,to meet the existing requirements of the development of productive power.In view of the above,a complete set of online visual inspection device of the flexible circuit board silicone rubber keypads positioning defect detection was designed and developed.The online detection of the common defects in the silicone rubber keypads positioning link on the product line was realized.The implementation mechanism and the main defects of the flexible circuit board silicone rubber keypads positioning are briefly described.The characteristics of the defects were analyzed and summarized,and the key points and difficulties of the detection of the silicone rubber keypads positioning defects based on machine vision were summarized.The online visual inspection system of keyboard flexible circuit board silicone rubber keypads positioning is designed,which integrates image acquisition,data processing and information display.The research contents of this paper focused on the following aspects:First,the optical devices such as cameras,lens and light sources were selected according to the actual demand of detection,the hardware part of detection system was designed according to the existing product line,and the software was designed according to the characters and functional requirements of the online detection system.Secondly,binocular calibration was adopted to mosaic the images,weighted superposition method was used to process the overlap range of neighboring cameras to eliminate the influences caused by the seams between images.Thirdly,Gaussian filter and the dynamic thresholding was used to obtain the regions of silicone rubber keypads.The affine transformation reduced the influence of the movement of the positioning mode at utmost.Finally,average gray values were adopted to detect position leak and static coordinate matching was adopted to detect excess.The Blob Analysis was ingeniously used to detect detects of the states of silicone rubber keypads.The morphological features and the apological properties were used to realize deflective silicone rubber keypads and inverted silicone rubber keypads detect detection.In the end,according to the features of the silicone rubber keypads positioning and the current situation of the production lines,a set of online keyboard flexible circuit board silicone rubber keypads positioning detect detection method was studied.The method's test time was within 3200 ms and the average detection error rate could reach 0.76%,basically meet the requirements for enterprise. |
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