Research On Anti-counterfeiting Technology Of Three-dimensional Imaging Based On Microlens

The three-dimensional imaging technology based on microlens has novel methods,strong dynamic sense of stereo image moving observation,continuous viewing angle,large observable area,full parallax,and broad application prospects in anti-counterfeiting.However,due to the single micro-pattern,there will be potential risks of moire magnification anti-counterfeiting label being imitated.Integrated imaging anti-counterfeiting technology is difficult to imitate.Combining with digital printing technology,naked-eye 3D anti-counterfeiting pattern can be prepared,which is more convenient and environmentally friendly than the original lithography technology.However,there are few related researches at present.In this paper,aiming at the above problems,the mechanism of three-dimensional imaging anti-counterfeiting technology based on micro-lens is theoretically analyzed and experimentally studied,aiming at improving the imaging mechanism of naked-eye 3D image and enriching its rendering effect.The main research contents and conclusions are as follows:(1)Based on the principle of vernier moire magnifier,the moire magnification formula of planar microlens is established.The magnification ratio of moire pattern to micro-pattern is approximately equal to the ratio of the periodic vector of microlens array to the periodic vector difference of planar microlens array and micro-pattern array.The formula can predict the location and size of micro-pattern mapping,and provide a theoretical basis for the further study of moire magnification anti-counterfeiting technology.A square aperture planar microlens array with 0.3 mm aperture edge length and 0.313 mm period is used to verify the conformity of the moire pattern with the micro-patterns of different periods and angles.The experimental results of the location and size of the moire pattern are consistent with the theoretical prediction.(2)The anti-counterfeiting technology with gradient effect is studied according to the magnification formula of plane micro-lens moire pattern and the depth of field calculation formula of three-dimensional image.The anti-counterfeiting technology with ripple effect is studied by combining triangular function with the magnification rule of plane micro-lens moire pattern.The difficulty of imitation is raised and the printed samples with gradient and ripple display effect are prepared(3)Compiling the program of generating the micro-pattern information layer can generate five types of micro-pattern arrays:circle,square,diamond,triangle and text,forming four effects:suspension,subsidence,ripple and gradual change(4)The integrated imaging anti-counterfeiting technology based on digital printing is studied.Printing samples containing two letters of different depth of field are prepared by using camera array recording and synthetic element images.The relationship between the spacing of the same name image points and the position of stereo image reconstruction under parallel camera array is verified.The experimental results show that the stereo effect of the sample is good,and the experimental values of the reconstruction position of the stereo image are basically consistent with the theoretical prediction,and the error is small.