|
File:Methyl-orange-3D-balls.png|thumb|Methyl-orange-3D-balls File:DisperseOrange1.png|thumb|DisperseOrange1 File:Solvent Yellow 124.svg|thumb|Solvent Yellow 124 During the last century, dichroic dyes had been used as electric field responsive colorants for rugged avionics and armored vehicle electronic displays(2). In general, dichroic dye displays had more predictable performance than twisted nematic liquid crystal displays or plasma displays. These displays were used in early (Boeing ) 757 and 767 models, and the displays were manufactured by Lockheed Martin, Honeywell, amongst others(2). In the Sovient Union, dye research was extensively performed by (Niopik ). Currently dichroic displays for avionics is manufactured in the USA by (Transicoil ) and (Polytronix. ) Dichroic displays are also manufactured by (AlphaMicron ) , amongst others. Many dyes exhibit dichroism(1). Some of these dyes are soluble in commercial liquid crystals(4). After considerable research, azo dyes and anthraquionone dyes have proven suitable for use for liquid crystal displays(2). These dyes have adequate lightfastness, suitable wavelength bands, and sufficient order parameter in a liquid crystal host to function as display ingredients. Obtaining dyes with sufficient order parameter in the liquid crystal host has been one of the primary challenges to the adoption of dichroic dyes by industry(2). Although many azo dyes and anthraquinone dyes exhibit some dichroism, most common industrial dyes do not have sufficient dichroic order parameter to function as display ingredients. In order to achieve dyes with sufficient order parameter, researchers have synthesized novel dyes which themselves are liquid crystalline in character to function as display ingredients. The challenges that researchers face are : (1) high purity (2) small quantities and (3) high efficiency. A few companies have overcome these challenges, such as (Mitsui Toatsu ) in Japan and (Merck ) in the U.K. File:Examples of dichroic dyes.pdf|thumb|Dichroic dyes Dichroic dyes differ from electrophoretic charged particle displays, commonly called E-Ink. Azo and anthraquinone dyes are available across the visible spectrum(2), although there are few, if none, green colored dyes with sufficient order parameter for display use. Currently dichroic dyes are used in switchable windows and in some special purpose displays and consumer novelty goods. Reviews of dichroic dyes, and dichroic dyes for displays have been written by Dr. Hans Zocher, Dr. Birenda Bahadur, Dr. Aleksandr V. Ivashchenko, and patents by Mr. John Dreyer, and Dr. Allan Land. Further Reading : Liquid Crystals: Applications and Uses, Volumes 1-3, edited by Birenda Bahadur, World Scientific, 1992. Chapter 11 Dichroic Liquid Crystal Displays and (Google Books. ) REFERENCES : (1) Originalaufsätze Und Berichte Naturwissenschaften December 1925, Volume 13, Issue 49, pp 1015-1021 Über die optische Anisotropie selektiv absorbierender Stoffe und über mechanische Erzeugung von Anisotropie Hans Zocher (Springer ) (2) Molecular Crystals and Liquid Crystals (Molecular Crystals and Liquid Crystals ) Volume 109, Issue 1, 1984 DOI:10.1080/00268948408080827 Birendra Bahadura pages 3-93 (3) Patents by John Dreyer (John Dreyer ) (4) Dyes in liquid crystals IVASHCHENKO A. V. (1) ; RUMYANTSEV V. G. ; Affiliation(s) du ou des auteurs / Author(s) Affiliation(s) (1) Organic intermediates dyes inst. (Niopik), Moscow, Molecular crystals and liquid crystals ISSN 0026-8941 CODEN MCLCA5 1987, vol. 150 Gordon and Breach, London. (Molecular Crystals and Liquid Crystals ) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Dichroic dyes, electronic dyes, liquid crystalline dyes」の詳細全文を読む スポンサード リンク
|