Pupil‐Adaptive Retina Projection Augment Reality Displays With Switchable Ultra‐Dense Viewpoints
Haonan Jiang, Yue‐Chu Cheng, Zhibo Sun, Zhengnan Yuan, Huajian Jin, Yipeng Huo, Man Chun Tseng, Fion Sze Yan Yeung, Hoi Sing Kwok, Enguo Chen
Abstract
Abstract Multi‐viewpoint retina projection displays (RPD) with an expanded visible range have been utilized in recent augmented reality (AR) systems to address the vergence‐accommodation conflict (VAC) by providing a long depth of field (DOF). However, these fixed multi‐viewpoint RPD systems still face a common critical challenge of imaging overlap or discontinuity when eyes rotate or under varying ambient light. To address this, an RPD AR system featuring switchable ultra‐dense viewpoints is presented, enabled by a photo‐alignment liquid crystal Dammann grating (p‐LCDG). The number of viewpoints reaches 49, which forms an ultra‐high density of diffraction lattice in front of the pupil with a record high rotation precision of 1.28°/viewpoint, allowing for a substantial range of 36 mm 2 . More importantly, the spacing of adjacent viewpoints is 0.532 mm, much smaller than the minimum radius of the pupil (≈1 mm). To facilitate viewpoint switching, a light selector is implemented, ensuring that only the light from a specific viewpoint reaches the eye, which effectively eliminates the image missing or discontinuity. By combining eye tracking technology, the viewer can consistently perceive a singular and clear image from the proposed RPD system, achieving seamless switching of viewpoints. This innovative design paves the way for high‐performance RPDs in AR applications.