Augmented reality with image registration, vision correction and sunlight readability via liquid crystal devices

Abstract

Augmented reality (AR), which use computer-aided projected information to augment our sense, has important impact on human life, especially for the elder people. However, there are three major challenges regarding the optical system in the AR system, which are registration, vision correction, and readability under strong ambient light. Here, we solve three challenges simultaneously for the first time using two liquid crystal (LC) lenses and polarizer-free attenuator integrated in optical-see-through AR system. One of the LC lens is used to electrically adjust the position of the projected virtual image which is so-called registration. The other LC lens with larger aperture and polarization independent characteristic is in charge of vision correction, such as myopia and presbyopia. The linearity of lens powers of two LC lenses is also discussed. The readability of virtual images under strong ambient light is solved by electrically switchable transmittance of the LC attenuator originating from light scattering and light absorption. The concept demonstrated in this paper could be further extended to other electro-optical devices as long as the devices exhibit the capability of phase modulations and amplitude modulations.

59‐1: Liquid Crystal Technology for Solving Key Optical Challenges in Virtual and Augmented Realities

“…To realize natural depth of focus to resolve vergence -accommodation conflict (VAC) 1 in AR/VR HMDs, four different displays have been investigated: light-field displays, volumetric displays, multiple-image planes and varifocal displays. Along with mechanical methods 3 , LC tech have been explored widely for solving VAC: 1) Using LC lenses 33 to create multiple-image planes 34 or varifocal displays 35 , or volumetric displays 36 ; 2) Using LC light shutters to create volumetric displays 37 ; 3) Using multiple LC displays to create light-field displays 2 .…”

P‐100: Ultra‐Large Field‐of‐View Retinal Projection Display with Vision Correction

“…This implies that the object distance s could be adjusted by the eye. This phenomenon would be very helpful for the image registration [2]-the alignment between the virtual and real objects-even without resorting to any zoom lens. By invoking the theorem of similar triangles, the size O of the virtual object can be easily deduced as…”

“…Today, the ultimate solution for a see-through near-eye display (NED) that would perfectly live up to the standards of augmented reality is still an open question. As far as the cost of fabrication is concerned, combiner-based NEDs [1][2][3] are preferred. However, due to the size of beam splitters and semi-reflective mirrors, such NEDs-if designed with a large field of view (FOV)-are often bulky and heavy.…”

Electrically Tunable Liquid Crystal Lenses for Augmented Reality

“…[3][4][5] In this paper, we introduce an AR system with two LC lenses which could simultaneously solve two challenges of registration and vision correction. [6] The concept mentioned in this paper could be further extended to other AR systems, and the LC lenses could be replaced by other devices as long as they exhibit the capability of tunable lens power.…”