Design and stray light analysis of a lenslet-array-based see-through light-field near-eye display

This study proposes an optical-see-through light-field near-eye display (OST LF-NED) based on integral imaging (InI) using a discrete lenslet array (DLA). A light-field image is used as the image source. A special microdisplay array built on a transparent substrate is used as the screen. A DLA is used as a spatial light modulator (SLM) to generate dense light field of the 3-D scene inside the eyebox of the system and provide correct focus cues to the user. The key to realize the OST capacity is that the microdisplays and the lenslets are both discretely-arranged so that the light from the real world passes directly through the gaps among the microdisplays on the transparent substrate and then the flat portion on the DLA panel, providing a clear view of the real world as well as the virtual information. The stray light can be totally eliminated in the region of the eyebox in ideal situations. In practical situations, take the limitation of the F-number into consideration, a trade-off between the size of eyebox and the stray light is made. Analysis and simulation of the stray light are conducted in detail. A ring-shaped aperture on each lenslet is added to reduce the stray light significantly by blocking the screen light that passes by the outer edge of each lenslet. The simulation shows that the proposed method is capable of providing an OST view in LF displays.