AR Displays: Next-Generation Technologies to Solve the Vergence–Accommodation Conflict

R. Zabels, Krišs Osmanis, Mārtiņš Narels, Uģis Gertners, Ainārs Ozols, Kārlis Rūtenbergs, Ilmārs Osmanis

Applied Sciences · 2019 · 50 citations · 24 references

DOIFull text

Open access

Concepts

TL;DR

Augmented reality offers many benefits, but conventional stereoscopic displays cause a vergence–accommodation conflict and fail to precisely overlay 3D content, limiting near‑work performance. The study aims to develop a near‑work‑capable AR display that eliminates the vergence–accommodation conflict by adopting a new technology. LightSpace Technologies created a static multifocal display using stacked liquid‑crystal diffusers and a high‑refresh‑rate projector to project depth‑plane images onto separate diffuser elements, producing a continuous 3D perception. A six‑plane system delivering 6 cpd resolution and 72° horizontal field of view achieved perceptually continuous accommodation across a 3.2‑diopter range, and a subsequent optimization with a conventional combiner produced a compact, practical AR display.

Abstract

Augmenting reality (AR) holds many benefits in how people perceive information and use it in their workflow or leisure activities. A cohesive AR experience has many components; nevertheless, the key is display technologies. The current industry standard for the core solution is still conventional stereoscopy, which has proven to be inadequate for near-work due to the caused vergence–accommodation conflict and the inability to precisely overlay the 3D content on the real world. To overcome this, next-generation technologies have been proposed. While the holographic method holds the highest potential of being the ultimate solution, its current level of maturity is not sufficient to yield a practical product. Consequently, the next solution for near-work-capable AR displays will be of another type. LightSpace Technologies have developed a static multifocal display architecture based on stacked liquid crystal-based optical diffuser elements and a synchronized high-refresh rate image projector. A stream of 2D image depth planes comprising a 3D scene is projected onto respective physically-separated diffuser elements, causing the viewer to perceive a scene as continuous and having all relevant physical as well as psychological depth cues. A system with six image depth planes yielding 6 cpd resolution and 72° horizontal field-of-view has been demonstrated to provide perceptually continuous accommodation over 3.2 Diopter range. A further optimization by using a conventional image combiner resulted in the compact and practical design of the AR display.

References

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