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Flexible Plastic Liquid Crystal Displays

Published online by Cambridge University Press:  15 March 2011

John L. West
Affiliation:
Liquid Crystal Institute, Kent State University Kent, Ohio 44242, USA
Greg R. Novotny
Affiliation:
Liquid Crystal Institute, Kent State University Kent, Ohio 44242, USA
Michael R. Fisch
Affiliation:
Liquid Crystal Institute, Kent State University Kent, Ohio 44242, USA
David Heineman
Affiliation:
Liquid Crystal Institute, Kent State University Kent, Ohio 44242, USA
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Abstract

Flexible plastic liquid crystal displays (LCDs) offer a number of advantages over traditional glass displays. Roll-to-roll manufacturing of such displays makes possible large size, inexpensive displays. While this type of manufacturing is still in the future, here we report solutions of some of the pressing problems needed to achieve this goal. We utilize liquid crystal effects that do not require polarizers and can therefore utilize commercially available, birefringent substrates such as polyesters and polyethylene terephthalate. We achieve excellent optical and mechanical performance of these flexible displays, even when bent, by creating polymer networks and polymer walls that adhere the front and back substrates and maintain uniform spacing between the substrates. Roll-to-roll processing of flexible plastic displays also requires that the photolithographic techniques used to pattern the electrodes on the current glass LCD’s be replaced by printing techniques and the development of techniques to rapidly etch unwanted electrode material. We must also develop and optimize techniques for rapidly forming polymer walls. Here we report methods of patterning ITO electrodes on flexible plastic substrates using conventional wax transfer printing techniques and rapid etching and cleaning techniques. We also report experiments that elucidate the basic science of rapidly forming polymer walls. We combine these new achievements and understanding and demonstrate their utility by fabricating a flexible plastic LCD using techniques compatible with roll-to-roll manufacturing. Finally, we discuss the critical issues that must be addressed if flexible plastic LCD’s are to reach their full potential.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

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References

REFERENCES

1. Doane, J. W., Vaz, N., Wu, B. G., and Žumer, S., App. Phys. Lett. 48, 269 (1986).Google Scholar
2. Yang, D.-K. and Chien, L.-C. and and Fung, Y. K. in Liquid Crystals in Complex Geometries formed by polymers and porous networks, ed. Crawford, G. P. and Žumer, S. (Taylor and Francis, 1996) pp. 103142.Google Scholar
3. Yamada, N., Kohzaki, S., Funada, F., and Awane, K., Sid Digest of Technical Papers, 575 (1995).Google Scholar
4. Yang, D.-K. and Chien, L.-C. and and Doane, J. W.,”Current Trends in Polymer dispersed Liquid Crystals,” Conference Record of the IDRC, p 49, 1991.Google Scholar
5. West, J.L., Akins, R. B., Francl, J., and Doane, J. W.,”Cholesteric/polymer dispersed light shutters,” App. Phys. Lett., vol. 63, pp. 1471–73, 1993.Google Scholar
6. West, J. L., Rouberol, M., Francl, J., Ji, Y., Doane, J. W. and Pfeiffer, M.,”Flexible displays Utilizing Bistable, reflective Cholesteric/Polymer Dispersions and Polymer Substrates,” Proc. Asia Display ’95, pp. 5557, 1995.Google Scholar
7. Ji, Y., Francl, J., and West, J. L.,”The mechanism for the formation of polymer wall in higher polymer content cholesteric liquid crystal mixture,Mol. Cryst. Liq. Cryst., vol. 299, pp. 395400, 1997.Google Scholar
8. Kim, Y., Francl, J., Taheri, B., and West, J. L.,”A method for the formation of polymer walls in liquid crystal/polymer mixtures,” Appl. Phys. Lett., vol. 72, pp. 22532255, 1998.Google Scholar
9.See for example: Landau, L. D. and Lifshitz, E. M., Electrodynamics of Continuous Media (Pergamon, New York, 1984) pp 6469.Google Scholar
10. Heineman, D., MS thesis, Kent State University, Dec. 2001.Google Scholar