Super-resolution foveated imaging system for near-eye display (NED) using tilting concave mirror

Abstract

The visual performance, in terms of both the resolution and the field of view (FOV), of a single near-eye display (NED), is often restricted by its pixel density. There are plenty of attempts to solve this issue in the research literature, but those solutions would adversely affect the system's form factor. This paper discusses an advanced foveated imaging system using a dual display with a built-in tilting feature, which allows efficient integration with external eye-tracking systems. One of the displays generates a super-resolution foveal image when it experiences optical minimization upon reflection on a fabricated tilting concave mirror (TCM). Besides that, the TCM capable of up to eight-directional actuation with its mechanism governed by four hydraulic pressure-driven membrane-formed cavities (MFCs). The other display that does not undergo any optical modification creates a low-resolution peripheral view. Subsequently, a foveated image with a wide FOV is projected through an eyepiece lens when images from both displays are combined. Here, the apparent foveal image experiences about five times enhancement at a system dimension of 12 x 10 x 5 cm. Furthermore, the achieved tilting range of the TCM reaches about 20 degrees in both the x and y-direction. This system design, which aims to mimic the perception of a human eye to provide a realistic viewing in a NED, has challenged the conventional trade-off issue between resolution and FOV as well as the relative form factor.