Light Field 3D Printing Mechanism And System Research

In recent years, fake and shoddy goods are increasingly rampant, and the anti-counterfeiting technology with two-dimensional graphics or texts as the identification information has been unable to meet the security requirements of famous products.Three-dimensional graphics display technology is focused widely due to the advantages of containing giant information capacity,providing vividly visual effcet,and being replicated difficultly.Among all the existing methods,the integral imaging technology based on microlens array attracts considerable attention because it can provide three dimensional images for the observer with a complete parallax, continuous view, without any observation of glasses and special light etc.In this paper,a technique of recording and reconstrcuting 3D graphics based on integral imaging is researched and explored. The prepared microlens film which has float or sink 3D images printed by light field method can be applied widely for security and anti-counterfeiting in the field of card, license plate,banknotes,trademarks and so on.The theoretical analysis and experimental study on the technological mechanism are carried out in this paper,and the main research contents and results are as follows:(1)the mechanism and system of 3D light field printing is researched and designed from the theory firstly.The 3D graphic sampled pixel is simulated by a converging point light field and the different angel divergent rays recorded by the photosensitive medium in the microlens film,so all the pattern pixel space position information can be output and recorded through moving the platform to adjust the focal point.According to the principle of the reversibility of light, the three-dimensional image of the reconstructed image can be seen from the reflected or transmitted light under ambient light.(2)The proposed scheme and experiments that printing multi-view graphics on the film verify the correctness and feasibility of the light field printing princple.Themicroscopic observation and measurement results show that the resolution of the mico graphics array approaches the above 4000 dpi which explains the high anti-counterfeiting security features of the prepared printing mateials.(3)A variety printing programs to obtain a point light field are proposed.According to the methods, a light field engineering printer was desinged and produced, and a kind of periodic three-dimensional spiral pattern was printed on the reflective film and the self-made micro lens array film.The main innovation of this thesis is a method that using galvanometer scanning on the converging cylindrical lens surface to produce a focus.Experimental results show that an excellent 3D visual effect can be experienced and the FOV(field of view)reaches above 30 degrees to observe the dynamic characteristics of the reconstructed image.