Guest Host Displays, Dichroic Displays, Polymer Dispersed Displays Guest host displays are similar to more common liquid crystal displays, but also include polymers, inorganic particles, or dichroic dye within the liquid crystal matrix. In dichroic dye displays, as the birefringence of the host liquid crystals change from planar to perpendicular orientation, the guest dyes also change orientation, from absorbing / planar orientation, to non-absorbing / perpendicular orientation. ] Unlike common TN or STN liquid crystal displays, guest host displays are typically driven direct, and are not usually multiplex driven. In addition, guest host displays usually require higher operating voltages than TN or STN displays. For example, the polymer dispersed liquid crystal display, is usually operated at voltages from 4.5 V to 24 V to as high as 100 V. Similarly, dichroic dye containing guest host displays, require voltages from 4.5 V to 10 V and higher. However, the P.D.L.C. display and many dichroic dye containing guest host displays, such as the White-Taylor Phase Change display, do not require polarizers, which is a significant advantage over TN or STN displays. Lacking polarizers these displays commonly have lower contrast than TN or STN displays, But are often sunlight readable, and usually have no backlight, and hence no backlight glare. Polarizer free displays enable low cost devices, since the polarizer is one of the more expensive components comprising the common liquid crystal display. Lacking polarizers, the guest host display substrates can be manufactured from low cost birefringent plastic films. And the plastic film substrates enable additional economies such as continuous R2R manufacturing of the displays, with its inherent economies over batch manufacturing processes. Continuous manufacturing of displays is described in U.S. Patents , , , and patents pending. In some cases, the R2R manufacturing of the guest host displays can be integrated with other roll to roll manufacturing process. For example, automated pick and place machines, such as a rotary circuit board placement machine from or a linear actuator, , with bulk tube feeders from , , , can automate the placement of driver circuit boards and other components. Advances in A.C.A. and A.C.F. conductive adhesives further enable the automated assembly of displays. Recent advances in transparent conductive polythiophene coated substrates make display electrodes which resist cracking and breaking, unlike common oxide based transparent conductors. Advances in Nanoimprint Lithography enable precise micro scale and nano scale embossing of display spacers, gaskets, and edge seals R2R. Processes similar to N.I.L. are described in U.S. Patents , , , , , and patents pending. teaches that "... sufficiently low for maintaining a proper operation of the most sensitive FLCD cells." Flexible substrates also enable greater design flexibility for the product designer, allowing flexible, conformal, die cut displays which complement the overall product design. R2R manufacturing of displays is promoted by the non-profit , the non-profit , and R2R intelligent packaging is promoted by the . Academic research and development is currently being done at the Glenn H. Brown Liquid Crystal Institute at Kent State University, at the Arizona State University , at the , at the VTT Technical Research Centre, at , at the University of Hamburg, and at the University of Stuttgart . Guest host displays consume electrical current much more slowly than l.e.d.s, giving them operating life spans of several months, versus the short lifespans of battery operated l.e.d.s. P.D.L.C. displays are commonly used as in homes, offices, and vehicles. Dichroic displays had been extensively researched as robust avionics for aircraft. Both P.D.L.C. Displays and dichroic displays can function as colorful animated skins for consumer products such as mylar balloons and greeting cards. Guest host displays commonly comprise liquid crystals, polymer or inorganic additives, twist agent, and optionally, dichroic dyes. Liquid crystals are distributed by Merck, , and . Dichroic dyes are distributed by . Displays are manufactured by , , , , Vitswell, , and by many others. Further reading : M. Randler, E. Lueder, V. Frey, J. Brill, M. Muecke, University of Stuttgart, Labor fuer Bildschirmtechnik, published by the Society for Information Display, Digest of Technical Proceedings. Liquid Crystal Dispersions Liquid Crystals Series, V0L 1 Volume 1 of Series on Advances in Mathematics for Applied Sciences Series on liquid crystals Editor Paul S. Drzaic Publisher World Scientific, 1995 , 9789810217457
Liquid Crystal Displays: Addressing Schemes and Electro-Optical Effects, by Ernst Lueder, Wiley, 2010, Chapter 21 and and at Flexible Flat Panel Displays, edited by Gregory Crawford, Wiley, 2005 and . See the chapter Barrier Layer Technology for Flexible and the chapter Roll-to-Roll Manufacturing of Flexible Liquid Crystals: Applications and Uses, Volumes 1-3, edited by Birenda Bahadur, World Scientific, 1992. Chapter 11 Dichroic Liquid Crystal Displays and Reflective Liquid Crystal Displays, by Shin-Tson Wu, Deng-Ke Yang, Wiley, 2001, Chapter 6 and Liquid Crystals In Complex Geometries: Formed by Polymer And Porous Networks, edited by G P Crawford, S Zumer, CRC Press, 1996. Conducting polymer substrates for plastic liquid crystal
