Augmented Reality Display Based On Reflective Liquid Crystal

Augmented reality(AR)display,combines the virtual and real world by an optical combiner and thus brings users new vision experience that is different from conventional displays such as cell phones and computers.However,many AR products in the market have some issues,such as accommodation-convergence conflict,low light efficiency,bulky size,and etc.Therefore,this dissertation focuses on AR optical systems,with the purpose of fixing accommodation-convergence conflict and enhancing AR performance.The research is mainly made of two parts:1.AR display based on a polymer stabilized blue phase liquid crystal(PS-BPLC)combiner.Half mirrors,beam splitters and gratings are commonly used as the optical combiner for an AR display.But half mirrors or beam splitters,could not achieve high transmittance of the environmental light and high reflectance of the virtual image light simultaneously.As for gratings,the fabrication process is complicated,thus restricting their application.PS-BPLC shows high reflectance to circularly polarized incident light while has high transmittance for real-world light.Therefore,employing a PS-BPLC film as combiner could boost both transmittance and reflectance,enhancing energy efficiency.Multi-plane display based on cholesteric liquid crystal(CLC).In many AR products,like Microsoft Hololens,Meta2,3D depth cues are provided by stereoscopic display technique,which could result in accommodationconvergence conflict,and then causes dizziness and discomfort.Multi-plane display is a kind of true 3D display technique,which is capable of rendering all depth information correctly.Aiming at solving problems like high driving voltage,we propose and experimentally verified a compact AR design with low switching voltage of 12 V,using CLC films.In the end,we present a multi-plane display system with more than 2 image planes.