Alignment rubbing

M Flamaguchi and K Yoshino, Polarized electroluminescence from rubbing-aligned poly(2,5-dinonyloxy-l,4-phenylenevinylene) films, Appl. Phys. Lett., 67 3381-3383, 1995. 

M Jandke, P Strohriegl, J Gmeiner, W Brutting, and M Schwoerer, Polarized electroluminescence from rubbing-aligned poly(phenylenevinylene), Adv. Mater., 11 1518-1521, 1999. 

In contrast the polymer 19 with branched alkyl chains displays only one nematic phase. Thus 19 shows a phase transition at 167 °C upon heating with the reverse transition upon cooling being seen at 132 °C. Annealing of a film of 19 at 185 °C upon a rubbing-aligned polyimide layer followed by rapid... 

To prevent tilt reverse disclination occurrence on microgroove surfaces, hybrid type cells with a rubbed alignment layer and a microgroove alignment layer have been proposed [7]. In Fig. 3.4.4(a), the liquid crystal configurations on... 

Fig. 3.4.3 Liquid crystalline alignment on alignment layer surfaces, (a) Two possible directions of molecular inclination on an alignment layer surface and a tilt reverse disclination. (b) The direction of molecular inclination on a rubbed alignment layer.

Polarised polymer LEDs have also been made from other conjugated polymers, and using different techniques. Some examples are rigid rod polymers [167], rubbing aligned PPV-derivatives [168], and tensile drawn PPV [169]. 

Since the invention of the twisted nematic (TN)-type LCD in 1970, rubbed alignment films have been used for the alignment of the liquid crystal molecules [53,54]. Until 1975, a wide variety of organic and inorganic materials had been developed in a trial-and-error fashion [55], but at present the use had been narrowed down to polyimide materials. In particular, in this chapter I want to review the developmental history of organic-solvent-soluble (soluble) polyimide alignment films that are currently widely used in high-definition LCD TVs. 

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