Spatially dispersed virtual images in augmented reality by exploiting an electronic progressive liquid crystal lens

Visual fatigue, a discomfort of the eyes resulting from a distance mismatch between projected virtual images and surrounding real objects, is a major challenge in optically see-through augmented reality (AR) systems. To address it, we develop a spatially distributed projection of virtual images in an AR system by exploiting an electronic progressive liquid crystal lens (EPLC lens), which enables spatially multifocal wavefront modulation. The lens power in the EPLC lens is spatially dispersed and electrically adjustable. The operating principle is introduced. By adjusting the applied electric fields, the EPLC lens functions as a positive progressive lens and a negative progressive lens capable of adjusting projected images from 262 cm to 35 cm even though the lens power of the EPLC lens ranges only from +2 diopters to -1 diopters. The impacts of the proposed approach are not only in AR applications, but also in machine vision as well as advanced driver assistance systems.