scholarly journals Liquid Crystal Based Head-Up Display with Electrically Controlled Contrast Ratio

Crystals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 311
Author(s):  
Yueda Liu ◽  
Yan Li ◽  
Quanming Chen ◽  
Sida Li ◽  
Yikai Su

With the growing demand for driving safety and convenience, Head-Up Displays (HUDs) have gained more and more interest in recent years. In this paper, we propose a HUD system with the ability to adjust the relative brightness of ambient light and virtual information light. The key components of the system include a cholesteric liquid crystal (CLC) film, a geometric phase (GP) liquid crystal lens, and a circular polarizer. By controlling the voltage applied to the GP lens, the contrast ratio of the virtual information light to ambient light could be continuously tuned, so that good visibility could always be obtained under different driving conditions.

2021 ◽  
Vol 29 (4) ◽  
pp. 6011
Author(s):  
Yannanqi Li ◽  
Tao Zhan ◽  
Zhiyong Yang ◽  
Chi Xu ◽  
Patrick L. LiKamWa ◽  
...  

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2430
Author(s):  
En-Lin Hsiang ◽  
Yannanqi Li ◽  
Ziqian He ◽  
Tao Zhan ◽  
Caicai Zhang ◽  
...  

Color-converted micro-light-emitting diode (micro-LED) displays with wide color gamut, high ambient contrast ratio, and fast response time are emerging as a potentially disruptive technology. However, due to limited optical density and thickness of the color-conversion film, the blue light leakage and low color-conversion efficiency still hinder their widespread applications. In this paper, we demonstrate a patterned cholesteric liquid crystal (CLC) polymer film with two special optical functionalities. On the green and red sub-pixels, the corresponding planar CLC texture acts as a distributed Bragg reflector for the blue light, which in turn improves the color conversion efficiency and expands the color gamut. On the blue sub-pixels, the corresponding focal-conic CLC texture acts as light scattering medium, which helps to reduce the angular color shift. Further analysis reveals that the patterned CLC film can alleviate the crosstalk between green and blue color filters. Therefore, compared to the display system without such a CLC film, our proposed device structure increases the color conversion efficiency by 143% (at ~90% Rec. 2020) and reduces average angular color shift Δu’v’ from 0.03 to 0.018 at the viewing angle with the most severe color shift. Such a patterned CLC film is applicable to all kinds of color-conversion display systems, including organic and inorganic phosphors.


2020 ◽  
Vol 28 (5) ◽  
pp. 450-456 ◽  
Author(s):  
Jianghao Xiong ◽  
Guanjun Tan ◽  
Tao Zhan ◽  
Shin‐Tson Wu

1983 ◽  
Vol 44 (10) ◽  
pp. 1179-1184 ◽  
Author(s):  
M. Vilfan ◽  
R. Blinc ◽  
J. Dolinšek ◽  
M. Ipavec ◽  
G. Lahajnar ◽  
...  

2020 ◽  
Vol 35 (9) ◽  
pp. 908-913
Author(s):  
Wei-xing GONG ◽  
◽  
Tao YU ◽  
Wei-zhi WANG ◽  
Jia-lun ZHANG ◽  
...  

RSC Advances ◽  
2020 ◽  
Vol 10 (68) ◽  
pp. 41693-41702
Author(s):  
Yunho Shin ◽  
Jinghua Jiang ◽  
Guangkui Qin ◽  
Qian Wang ◽  
Ziyuan Zhou ◽  
...  

A polymer stabilized LC based light waveguide display is reported. Performance is improved by patterned photo-polymerization or electrode. It has high brightness, ultrafast switching time, high contrast ratio, and high transmittance for transparent and augmented displays.


2008 ◽  
Vol 47 (6) ◽  
pp. 4751-4754 ◽  
Author(s):  
Sudarshan Kundu ◽  
Mitsuhiro Akimoto ◽  
Itaru Hirayama ◽  
Masaru Inoue ◽  
Shunsuke Kobayashi ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document