Editing Liquid-crystal display (section)

=== 1970s ===
On December 4, 1970, the [[twisted nematic field effect]] (TN) in liquid crystals was filed for patent by [[Hoffmann-LaRoche]] in Switzerland, ([http://www.lcd-experts.net/ Swiss patent No. 532 261] {{Webarchive|url=https://web.archive.org/web/20210309070121/http://www.lcd-experts.net/ |date=March 9, 2021 }}) with [[Wolfgang Helfrich]] and [[Martin Schadt]] (then working for the Central Research Laboratories) listed as inventors.<ref name="cast06" /> Hoffmann-La Roche licensed the invention to Swiss manufacturer [[Brown, Boveri & Cie]], its [[joint venture]] partner at that time, which produced TN displays for wristwatches and other applications during the 1970s for the international markets including the Japanese electronics industry, which soon produced the first digital [[Quartz watch|quartz wristwatches]] with TN-LCDs and numerous other products. [[James Fergason]], while working with Sardari Arora and [[Alfred Saupe]] at [[Kent State University]] [[Liquid Crystal Institute]], filed an identical patent in the United States on April 22, 1971.<ref>{{cite web | title=Modifying Light | work=American Scientist Online | url=http://www.americanscientist.org/template/AssetDetail/assetid/53321/page/4;jsessionid=aaa6J-GFIciRx2%3Ci%3ELive | access-date=December 28, 2007 | archive-url=https://web.archive.org/web/20081220055207/http://www.americanscientist.org/template/AssetDetail/assetid/53321/page/4;jsessionid=aaa6J-GFIciRx2%3Ci%3ELive | archive-date=December 20, 2008 }}</ref> In 1971, the company of Fergason, [[ILIXCO]] (now [[LXD Incorporated]]), produced LCDs based on the TN-effect, which soon superseded the poor-quality DSM types due to improvements of lower operating voltages and lower power consumption. Tetsuro Hama and Izuhiko Nishimura of [[Seiko]] received a US patent dated February 1971, for an electronic wristwatch incorporating a TN-LCD.<ref>{{cite web |url=https://patents.google.com/patent/US3881311A/en |title=Driving arrangement for passive time indicating devices |access-date=April 10, 2019 |archive-date=February 24, 2021 |archive-url=https://web.archive.org/web/20210224031847/https://patents.google.com/patent/US3881311A/en |url-status=live }}</ref> In 1972, the first wristwatch with TN-LCD was launched on the market: The Gruen Teletime which was a four digit display watch.

In 1972, the concept of the [[Active matrix|active-matrix]] [[Thin-film transistor|thin-film transistor (TFT)]] liquid-crystal display panel was prototyped in the United States by [[T. Peter Brody]]'s team at [[Westinghouse Electric (1886)|Westinghouse]], in [[Pittsburgh, Pennsylvania]].<ref>Brody, T. P., ''"Birth of the Active Matrix"'', Information Display, Vol. 13, No. 10, 1997, pp. 28–32.</ref> In 1973, Brody, J. A. Asars and G. D. Dixon at [[Westinghouse Electric Corporation|Westinghouse Research Laboratories]] demonstrated the first [[thin-film-transistor liquid-crystal display]] (TFT LCD).<ref name="Kuo">{{cite journal |last1=Kuo |first1=Yue |title=Thin Film Transistor Technology—Past, Present, and Future |journal=The Electrochemical Society Interface |date=January 1, 2013 |volume=22 |issue=1 |pages=55–61 |doi=10.1149/2.F06131if |bibcode=2013ECSIn..22a..55K |url=https://www.electrochem.org/dl/interface/spr/spr13/spr13_p055_061.pdf |issn=1064-8208 |doi-access=free |access-date=September 27, 2019 |archive-date=August 29, 2017 |archive-url=https://web.archive.org/web/20170829042321/http://www.electrochem.org/dl/interface/spr/spr13/spr13_p055_061.pdf |url-status=live }}</ref><ref>{{cite journal |last1=Brody |first1=T. Peter |author1-link=T. Peter Brody |last2=Asars |first2=J. A. |last3=Dixon |first3=G. D. |title=A 6 × 6 inch 20 lines-per-inch liquid-crystal display panel |journal=[[IEEE Transactions on Electron Devices]] |date=November 1973 |volume=20 |issue=11 |pages=995–1001 |doi=10.1109/T-ED.1973.17780 |bibcode=1973ITED...20..995B |issn=0018-9383}}</ref> {{As of|2013}}, all modern [[high-resolution]] and high-quality [[electronic visual display]] devices use TFT-based [[active matrix]] displays.<ref>{{cite book |last1=Brotherton |first1=S. D. |title=Introduction to Thin Film Transistors: Physics and Technology of TFTs |date=2013 |publisher=[[Springer Science & Business Media]] |isbn=9783319000022 |page=74 |url=https://books.google.com/books?id=E0x0Zghk7okC&pg=PT74}}</ref> Brody and Fang-Chen Luo demonstrated the first flat active-matrix thin-film transistor liquid-crystal display (AM TFT LCD) in 1974, and then Brody coined the term "active matrix" in 1975.<ref name="Kawamoto" />

In 1972 [[Rockwell International|North American Rockwell Microelectronics Corp]] introduced the use of DSM LCDs for [[calculator]]s for marketing by Lloyds Electronics Inc, though these required an internal light source for illumination.<ref>{{cite journal |last1=Dale |first1=Rodney |last2=Millichamp |first2=David |date=September 28, 1972 |title=Liquid Crystals Get Their Sparkle From Mass Market |journal=The Engineer |pages=34–36}}</ref> [[Sharp Corporation]] followed with DSM LCDs for pocket-sized calculators in 1973<ref>{{cite journal |date=December 1973 |title=What's New In Electronics: 100-hour calculator |journal=Popular Science |pages=87}}</ref> and then mass-produced TN LCDs for watches in 1975.<ref name="auburn">[https://web.archive.org/web/20051031052032/http://web6.duc.auburn.edu/~boultwr/lcdnote.pdf Note on the Liquid Crystal Display Industry], [[Auburn University]], 1995.</ref> Other Japanese companies soon took a leading position in the wristwatch market, like [[Seiko]] and its first 6-digit TN-LCD quartz wristwatch, and [[Casio]]'s 'Casiotron'. Color LCDs based on ''Guest-Host'' interaction were invented by a team at RCA in 1968.<ref>Heilmeier, G. H., Castellano, J. A. and Zanoni, L. A.: ''Guest-host interaction in nematic liquid crystals.'' Mol. Cryst. Liquid Cryst. vol. 8, p. 295, 1969.</ref> A particular type of such a color LCD was developed by Japan's Sharp Corporation in the 1970s, receiving patents for their inventions, such as a patent by Shinji Kato and Takaaki Miyazaki in May 1975,<ref>{{cite web|url=https://patents.google.com/patent/JPS51139582A/en|title=Liquid crystal display units|access-date=April 10, 2019|archive-date=February 24, 2021|archive-url=https://web.archive.org/web/20210224054525/https://patents.google.com/patent/JPS51139582A/en|url-status=live}}</ref> and then improved by Fumiaki Funada and Masataka Matsuura in December 1975.<ref>{{cite web|url=https://patents.google.com/patent/JPS5279948A/en|title=Liquid crystal color display device|access-date=April 10, 2019|archive-date=March 26, 2021|archive-url=https://web.archive.org/web/20210326064210/https://patents.google.com/patent/JPS5279948A/en|url-status=live}}</ref> [[TFT LCD]]s similar to the prototypes developed by a Westinghouse team in 1972 were patented in 1976 by a team at Sharp consisting of Fumiaki Funada, Masataka Matsuura, and Tomio Wada,<ref>{{cite web|url=https://patents.google.com/patent/JPS5327390A/en|title=Liquid crystal display device|access-date=April 10, 2019|archive-date=April 23, 2021|archive-url=https://web.archive.org/web/20210423180948/https://patents.google.com/patent/JPS5327390A/en|url-status=live}}</ref> then improved in 1977 by a Sharp team consisting of Kohei Kishi, Hirosaku Nonomura, Keiichiro Shimizu, and Tomio Wada.<ref>{{cite web|url=https://patents.google.com/patent/JPS5437697A/en|title=Liquid crystal display unit of matrix type|access-date=April 10, 2019|archive-date=March 13, 2021|archive-url=https://web.archive.org/web/20210313210308/https://patents.google.com/patent/JPS5437697A/en|url-status=live}}</ref> However, these TFT-LCDs were not yet ready for use in products, as problems with the materials for the TFTs were not yet solved.