Editing Liquid-crystal display (section)

=="Zero-power" (bistable) displays==
{{See also|Ferroelectric liquid crystal display}}

The zenithal bistable device (ZBD), developed by [[Qinetiq]] (formerly [[Defence Evaluation and Research Agency|DERA]]), can retain an image without power. The crystals may exist in one of two stable orientations ("black" and "white") and power is only required to change the image. ZBD Displays is a spin-off company from QinetiQ who manufactured both grayscale and color ZBD devices. Kent Displays has also developed a "no-power" display that uses polymer stabilized [[cholesteric liquid crystal]] (ChLCD). In 2009 Kent demonstrated the use of a ChLCD to cover the entire surface of a mobile phone, allowing it to change colors, and keep that color even when power is removed.<ref>{{cite web|title=&#91;SID&#93; Entire Surface of Handset becomes LCD|publisher=Nikkei Tech-On|author=Tetsuo Nozawa|url=http://techon.nikkeibp.co.jp/english/NEWS_EN/20090609/171529|access-date=June 10, 2009|archive-date=October 31, 2017|archive-url=https://web.archive.org/web/20171031215333/http://techon.nikkeibp.co.jp/english/NEWS_EN/20090609/171529/|url-status=live}}</ref>

In 2004, researchers at the [[University of Oxford]] demonstrated two new types of zero-power bistable LCDs based on Zenithal bistable techniques.<ref>{{cite web|title=Development of bistable displays |publisher=University of Oxford |author=Chidi Uche |url=http://www.eng.ox.ac.uk/lc/research/Gratingstructures.html |access-date=July 13, 2007 |url-status=dead |archive-url=https://web.archive.org/web/20080523234127/http://www.eng.ox.ac.uk/lc/research/Gratingstructures.html |archive-date=May 23, 2008}}</ref> Several bistable technologies, like the 360° BTN and the bistable cholesteric, depend mainly on the bulk properties of the liquid crystal (LC) and use standard strong anchoring, with alignment films and LC mixtures similar to the traditional monostable materials. Other bistable technologies, ''e.g.'', BiNem technology, are based mainly on the surface properties and need specific weak anchoring materials.