The Key Technology Research Of The 3D Light Field Display With Enlarging Depth Of Field

Compared with other naked eye 3D display technologies,light field display based on integrated imaging has no contradiction of radiance adjustment and no need of coherent light,so it becomes one of the most potential naked eye 3D display technologies.The limited depth of field limits the development of light field display in real scenes.The depth of field of light field display mainly includes range of depth of field and off screen depth.This paper mainly studies the depth of field of light field display through the analysis of these two indicators and the improvement methods.The main research content and innovation points of this dissertation are as follows:(1)The analysis and the improved method based on optical depth of focus of the range of depth of field for the 3D light field displayThe range of depth of field of light field display refers to the vertical range of clear display effect of three-dimensional scene projected by light field display device.Based on the theory of depth of focus in optics,the depth of field equation of light field display is deduced.The model indicates that the range of depth of field is positively related to the focal length of a single lens in the system lens array and negatively related to the aperture size.In this paper,a large depth of field display system based on cross-arrangement stop array is proposed.The system improves the range of depth of field from 6cm to 13cm by limiting the beam with aperture and cross-arrangement layout.Through the analysis of the acquisition and reconstruction process and real experiments,the feasibility of the proposed method is proved.(2)The analysis method and the improved method based on view point density of the off screen depth for the 3D light field displayThe off screen depth of light field display is another important reference index for the depth of field of light field display,which together with the range of depth of field determines the excellent stereoscopic effect of the display.According to the principle of similar triangle and the formula of viewpoint density of the whole system,it is concluded that the off screen depth is positively correlated with viewpoint density.In this paper,a method of reducing the pixel size is proposed to improve the viewpoint density and then increase the off screen depth.At the same time,the index of information transmission efficiency(ITE)is introduced to measure the display performance of the system.Theoretically,reducing the pixel size and increasing the off screen depth will not affect ITE.The simulation results verify the feasibility of the proposed method,reaizing the off screen depth from 18cm to 30cm.