18.5L: Late‐News Paper : Front‐lit LCOS for Wearable Applications

Liao²,

Chen

et al. 2018

Applied Sciences

In this paper, we review liquid-crystal-on-silicon (LCoS) technology and focus on its new application in emerging augmented reality (AR) displays. In the first part, the LCoS working principles of three commonly adopted LC modes—vertical alignment and twist nematic for amplitude modulation, and homogeneous alignment for phase modulation—are introduced and their pros and cons evaluated. In the second part, the fringing field effect is analyzed, and a novel pretilt angle patterning method for suppressing the effect is presented. Moreover, we illustrate how to integrate the LCoS panel in an AR display system. Both currently available intensity modulators and under-developing holographic displays are covered, with special emphases on achieving high image quality, such as a fast response time and high-resolution. The rapidly increasing application of LCoS in AR head-mounted displays and head-up displays is foreseeable.

Section: Introductionmentioning

confidence: 99%

Liquid-Crystal-on-Silicon for Augmented Reality Displays

Liao²,

Chen

et al. 2018

Applied Sciences

“…Liquid-Crystal-on-Silicon (LCoS) panel has been widely used for intensity modulation in augmented reality (AR) displays, such as Google Glass and Microsoft HoloLens, because of its high resolution, low driving voltage, and low power consumption [1][2][3]. To overcome the focus-cue mismatch issue, phase-only LCoS has found useful applications in focal surface displays [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

51‐3: High‐birefringence Liquid Crystal for Phase‐only Spatial Light Modulators

Chen

Symp Digest of Tech Papers

Li³

et al. 2018

“…Liquid-Crystal-on-Silicon (LCoS) panels have found promising applications in augmented reality (AR) near-eye displays because of their low operation voltage, high resolution density, broad bandwidth, compact size, and light weight [1][2][3][4][5]. Both amplitude modulation and phase modulation using LCoS have been demonstrated: 1) For amplitude modulation, 1π phase retardation and high contrast ratio are critically needed, making reflective 90° mixed-mode twist nematic (MTN) and vertical alignment (VA) LCoS panels two favored choices.…”

Section: Introductionmentioning

confidence: 99%

Fast-response liquid crystal phase modulators for augmented reality displays

2017

Opt. Express

We report three new liquid crystal mixtures optimized for the phase modulator of an augmented reality display. The mixtures exhibit a relatively high birefringence (Δn) yet low viscosity, modest dielectric anisotropy (Δε), and acceptable resistivity and UV stability. High Δn enables a thin cell gap (d≈1.7 μm) for achieving 2π phase change with a reflective Liquid-Crystal-on-Silicon (LCoS) device and ~2 ms average phase-to-phase response time at 40°C. The modest Δε helps lower the operation voltage to 5V. To improve the response time of a full-color LCoS, we propose a new driving method by shifting the operation voltage away from the threshold. We also applied such a high Δn LC mixture to LCoS based amplitude modulators and achieved submillisecond response time. Widespread applications of these materials for the emerging augmented reality displays are foreseeable.