Displays twisted nematics

The copolymerization gave copolymers displaying twisted nematic structures in a large interval of compositions. Grandjean textures and accompanying selective reflections of colors are easily obtained with these interesting new materials. [Pg.98]

The first stable commercial liquid crystal display (LCD) device was the twisted nematic (TN) [110], still widely... [Pg.2561]

A slight variant of the classic twisted nematic display has been iatroduced due to its wider viewiag angle and improved switching characteristics. [Pg.203]

Thermotropic cholesterics have several practical applications, some of which are very widespread. Most of the liquid crystal displays produced use either the twisted nematic (see Figure 7.3) or the supertwisted nematic electrooptical effects.6 The liquid crystal materials used in these cells contain a chiral component (effectively a cholesteric phase) which determines the twisting direction. Cholesteric LCs can also be used for storage displays utilizing the dynamic scattering mode.7 Short-pitch cholesterics with temperature-dependent selective reflection in the visible region show different colors at different temperatures and are used for popular digital thermometers.8... [Pg.428]

Supertwisted nematic display, 15 114 Super twisted nematic liquid crystal display (STN-LCD), 9 340 Super ultra-low emissions vehicle (SULEV), 13 855... [Pg.909]

Twisted polarised light Twisted nematic displays... [Pg.306]

Figure 5.3 Twisted nematic materials for direct drive displays.

Colour Displays from Twisted Nematic Liquid Crystals... [Pg.310]

Among the various LCDs, the three most widely used are (i) dynamic scattering display, (ii) twisted nematic display and (iii) guest-host display (Shanks, 1982). [Pg.464]

Afterwards there appeared what has become the main application liquid crystal displays (LCDs) based on the twisted nematic (TN) mode. These are commonly used for flat panel displays (e.g., desk calculators). Thin film transistor (TFT) LCDs enabled a large number of segments (e.g., 640 x 1024) to be used and they had advantages like... [Pg.407]

That both phenomena arise as a consequence of macroscopic solvent order and not Intimate solvent-solute Interactions Is clear Saeva and 01In (75) have shown that solute LCICD spectra can be observed In twisted nematic phases only Nakazaki et al. (76) find an excess of one enantiomer of hexahelicene Is produced photochemlcally from achiral precursors In twisted nematic phases no LCICD spectra or optical Induction occurs In untwisted nematic phases and the handedness of the twist can be correlated with the sign of the LCICD and the preferred product enantiomer. Furthermore, Isotropic phases of cholesteric mixtures display no discernible LCICD spectra (12, 67) and the enantiomeric excesses In products of photolablle reactants In Isotropic phases are near zero (51). [Pg.165]

Fig. 4.2 Structure of the different layers of an LC display shown in cross-section of a single pixel (twisted nematic cell).

Liquid crystals can display different degrees of long-range order, dependent on temperature, chemical composition, and the presence or absence of electric fields. In the nematic phase, the molecular axes point in a common direction, denoted by the director n but the molecular centers are otherwise arranged randomly. Because of the low degree of long-range order, nematic LCs have viscosities typical of ordinary liquids, and displays based on nematic LCs can operate at television frame rates. The most popular nematic-based display, the twisted nematic (TN), will be discussed in more detail below. [Pg.116]

Many different kinds of LCD displays can be constructed, but only twisted nematic (TN), dynamic scattering, and guest-host (GH) displays are presently of commerical importance. [Pg.116]

A twisted nematic display consists of a top electrode and bottom electrode, typically spaced 10 pim apart, whose surface alignments are perpendicular. The director, which is parallel to the surface, therefore rotates by 90° from top to bottom. Light enters the device at the top through a... [Pg.116]

Big Chemical Encyclopedia