Bistability zenithal bistable device

Fig. 7.15. The vertically aligned nematic-hybrid aligned nematic (VAN-HAN) zenithal bistable device geometry. The homeotropic state (left) is black while the hybrid state (right) is bright.

Zenithal bistable devices have been used in several types of electro-optic geometry. In the VAN-HAN mode, Fig. 7.15, one ZBD surface is combined with a fiat homeotropic surface. In the planar ZBD state (Fig. 7.15 right), the nematic is hybrid aligned with the director plane rotated 45° with... 

Here we consider only homeotropic grating surface alignment. A zenithal bistable device surface can also be realized with planar surface anchoring on the grating surface. ... 

T.J. Spencer and C.M. Care, Lattice Boltzmann scheme for modeling liquid-crystal dynamics Zenithal bistable device in the presence of defect motion, Phys. Rev. E 74(6), 061708/1-14, (2006). doi 10.1103/PhysRevE.74.061708... 

J.C. Jones and S. Beldon, 10.4 High image content zenithal bistable devices, SID Symp. Digest Tech. Papers 35(1), 140 143, (2004). doi 10.1889/1.1825769... 

Vertically aligned nematic Weak electrolyte model Zenithal bistable device... 

E. L. Wood, G. P. Bryan-Brown, P. Brett, A. Graham, J. C. Jones and J. R. Hughes, Zenithal bistable device (ZBD) suitable for portable applications, SID Inti. Symp. Digest Tech. Papers, 31, 124 (2(X)0). 

In contrast to other bistable nematic modes the surface state of the director does not change in zenithal bistable mode devices, which gives them an important robustness. In other words, while the device is bistable, the director state at the ZBD surface is monostable. This feature gives a smaller temperature dependence than other modes utilizing weak anchoring and multiple surface states. Among the many similarities with FLC devices there is also the fact that the stable states are polarized, i.e. they have a non-zero polarization in bulk. Therefore we anticipate problems with im-... 

L.A. Parry-Jones, R.B. Meyer and S.J. Elston, Mechanisms of flexoelectric switching in a zenithally bistable nematic device, J. Appl. Phys. 106(1),... 

C.V. Brown, L. Parry-Jones, S.J. Elston and S.J. Wilkins, Comparison of theoretical and experimental switching curves for a zenithally bistable nematic liquid crystal device. Mol. Cryst. Liq. Cryst. 410(1), 417-425, (2004). doi 10.1080/15421400490433451... 

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