Jpn. J. Appl. Phys. 38 (1999) pp. 805-808 |Next Article| |Table of Contents|
|Full Text PDF (136K)| |Buy This Article|
Alignment-Controlled Holographic Polymer Dispersed Liquid Crystal for Reflective Display Devices
Integrated Information & Energy Systems Laboratories,
Nippon Telegraph and Telephone Corporation, Tokyo 180-8585, Japan
(Received August 4, 1998; accepted for publication November 17, 1998)
A new type of holographic polymer dispersed liquid crystal (HPDLC) device in which liquid-crystal (LC) alignment is controlled by polymerized layers has been developed. In the alignment-controlled HPDLC device, the polymerized regions (polymer layers) are formed periodically in homogeneously aligned LC. When an electric field is applied vertically between the substrates, the LC molecules in the residual regions (LC layers) rotate towards the electric field. This causes a difference in refractive index between the polymer layers and LC layers, so selective reflection occurs in accordance with Bragg's law. The selectively reflected light shows strong polarization dependence. Only light polarized parallel to the alignment direction of LC molecules is reflected.
KEYWORDS:PDLC, polymer-dispersed liquid crystal, holographic, HPDLC, reflection, color, display, alignment
- K. Tanaka, K. Kato, S. Tsuru and S. Sakai: J. SID 2 (1994) 37.
- K. Tanaka, K. Kato, M. Date and S. Sakai: SID Int. Symp. Dig. Tech. Pap. 26 (1995) 267.
- M. Date, N. Naito, K. Tanaka, K. Kato and S. Sakai: Proc. 15th Int. Display Research Conf. Asia Display, SID, Hamamatsu, 1995, p. 603.
- M. Date, K. Tanaka, K. Kato and S. Sakai: Proc. 16th Int. Display Research Conf. Euro Display, SID, Birmingham, 1996, p. 515.
- M. Date, Y. Takeuchi and K. Kato: IEICE Trans. Electron. E81-C (1998) 1685.
- J. W. Doane: Liquid Crystals Applications and Uses, ed. B. Bahadur (World Scientific, Singapore, 1990) Vol. 1, Chap. 14, p. 361.
- D. J. Broer, J. Boven and G. N. Mol: Makromol. Chem. 190 (1989) 2255.
- D. J. Broer, R. A. M. Hikmet and G. Challa: Makromol. Chem. 190 (1989) 3201.