Opt Lett. 2022 Feb 1;47(3):445-448. doi: 10.1364/OL.438855.
A Maxwellian display presents always-focused images to the viewer, alleviating the vergence-accommodation conflict (VAC) in near-eye displays (NEDs). Recently, many methods of improving its limited eyebox have been proposed, among which viewpoint replication has attracted a lot of attention. However, double-image, blind-area, and image-shift effects always happen in typical eyebox-replication Maxwellian NEDs when the eye moves between the replicated viewpoints, which prevents these NEDs from being applied more widely. In this Letter, we propose a method for designing a holographic Maxwellian NED system with continuous eyebox replication as well as flexible interval adjustment by changing the projection angles of the reconstructed images. Thus, holograms corresponding to the positions of different viewpoints are calculated to match the interval of the replicated viewpoints with the human pupil diameter, making it possible to eliminate or alleviate double-image or blind-area effects. Also, seamless viewpoint conversion in the eyebox is achieved by aligning the images of adjacent viewpoints on the retina via hologram pre-processing independently. These effects are verified successfully in optical experiments and have the potential to be applied in near-eye three-dimensional displays without VAC.
麦克斯韦尔显示为观看者提供始终聚焦的图像，缓解了近眼显示（NED）中的聚散调节冲突（VAC）。最近，已经提出了许多改进其有限眼盒的方法，其中视点复制引起了广泛关注。然而，当眼睛在复制的视点之间移动时，典型的眼盒复制麦克斯韦尔 NED 中总会出现重影、盲区和图像移位等问题，这阻碍了这些 NED 的更广泛应用。在这封信中，我们提出了一种设计全息麦克斯韦尔 NED 系统的方法，通过改变重建图像的投影角度，可以实现连续的眼盒复制和灵活的间隔调整。因此，可以计算出与不同视点位置相对应的全息图，以匹配复制视点的间隔与人眼瞳孔直径，从而可以消除或减轻重影或盲区效应。此外，通过独立地对全息图进行预处理，使相邻视点的图像在视网膜上对齐，从而实现眼盒中的无缝视点转换。这些效果在光学实验中得到了成功验证，有望应用于无 VAC 的近眼三维显示。
