Twisted nematic liquid crystal displays

Gray GW, Kelly SM (1999) Liquid crystals for twisted nematic display devices. J Mater Chem 9 2037-2050... [Pg.216]

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

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]

It can be safely predicted that applications of liquid crystals will expand in the future to more and more sophisticated areas of electronics. Potential applications of ferroelectric liquid crystals (e.g. fast shutters, complex multiplexed displays) are particularly exciting. The only LC that can show ferroelectric property is the chiral smectic C. Viable ferroelectric displays have however not yet materialized. Antifer-roelectric phases may also have good potential in display applications. Supertwisted nematic displays of twist artgles of around 240° and materials with low viscosity which respond relatively fast, have found considerable application. Another development is the polymer dispersed liquid crystal display in which small nematic droplets ( 2 gm in diameter) are formed in a polymer matrix. Liquid crystalline elastomers with novel physical properties would have many applications. [Pg.465]

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]

Super-twisted nematic liquid crystal displays (STN-LCDs) 45000000... [Pg.1]

The twisted nematic liquid crystal display (TN-LCD) was reported by Schadt and Helfrich of F. Hoffman-La Roche in Basle, Switzerland in 1970. This was part of a tripartite collaboration between F. Hoffman-La Roche in Basle, Brown Boveri of Baden and Ebauche in Neuchatel, all in Switzerland. The intention was to design and develop flat panel displays, e.g. for digital watches. The first LCD factory was constructed in Lenzburg, Switzerland in the mid-1970s by Videlec, a subsidiary of Brown Boveri. Since then the TN-LCD has... [Pg.60]

Figure 3.7 Schematic representation of a twisted nematic liquid crystal display (TN-LCD). ...

Gooch and Tarry plot of transmission versus the coefficient, u, and the corresponding birefringence values, An, for a Twisted Nematic Liquid Crystal Display TN-LCD of thickness 6.55 pm operating between parallel polari-... [Pg.63]

The passage of light through a twisted nematic (TN) cell type of liquid crystal display (LCD) when the current to the electrodes is off (top) and when it is on (bottom). Liquid crystai dispiay iiiustration by Hans Cassidy. Courtesy of Gale Research. [Pg.78]

Certain aryl amines are endowed with unusual electronic properties. Schiff s bases such as 4-methoxybenzylidene-4-n-butylaniline were the original experimental chemicals used in the early development of electrical and electrooptical displays. Liquid crystal display (LCD) technology relies on twisted nematic or supertwisted nematic effects. Later nematogen development was based on cyanobiphenyls103. [Pg.772]

The twisted nematic (TN) and supertwisted nematic (STN) liquid crystals are widely used in liquid crystal displays. The former is used in wrist watches and calculators while the latter is used in notebook computers. [Pg.34]

Figure 9.12. Schematic representation of (a) a standard twisted-nematic liquid crystal display and (b) a related display equipped with a drawn nanocomposite. 1, incoming light (unpolarized) 2, polarizer 3, glass plate coated with an electrode layer and an orientation layer for the liquid-crystalline molecules 4, liquid-crystalline molecules forming a 90° helical twist in absence of a voltage or a linear array parallel to an electric field in presence of an electric field 5, nanocomposite with oriented arrays of metal particles. See color insert.

Figure 9.13. A twisted-nematic liquid crystal display (LCD) equipped with a poly(ethylene)-silver nanocomposite that had been annealed at 180°C for 15 hr and subsequently drawn as described in the text. The drawing axis of the nanocomposite is oriented parallel to the polarizer in the left image and perpendicular in the right image.

H. Seiberle and M. Schadt, LC-conductivity and cell parameters their influence on twisted nematic and supertwisted nematic liquid crystal displays. Mol. Cryst. Liq. Cryst. 239(1), 229-244, (1994). [Pg.135]

Prior to the development of thin film transistors (TFT) and active matrix technology for liquid crystal displays, the maximum number of hnes or rows in any display with an acceptable contrast was severely limited by the shallow voltage-transmission characteristics of, for instance, the twisted nematic mode. This inspired work to develop a liquid crystal device that could remain in either of two states (ideally black and white) after the removal of the electric field used to switch the liquid crystal into the selected state. With a memory in the liquid crystal an unlimited number of hnes can be displayed using a simple passive matrix and the constraints are instead in the refreshment requirements. [Pg.230]

Room temperature nematic liquid crystals have been developed for electro-optical applications [13-15]. In particular, twisted nematic (TN) liquid crystal displays have been widely used for practical display devices [ 13-15,38). In the TN cells, nematic liquid crystals form twisted alignment due to the influence of rubbed aligmnent polymer layers coated on the substrates (Fig. 7a). The TN cells are placed between two crossed polarizers. Without electric fields, the twisted LC aligmnent induces optical rotation of incident polarized... [Pg.224]

MULTIPLEXING LIMITS OF TWISTED NEMATIC LIQUID CRYSTAL DISPLAYS AND IMPLICATIONS FOR THE FUTURE OF HIGH INFORMATION CONTENT LCDs... [Pg.79]

LIMITS OF TWISTED NEMATIC LIQUID CRYSTAL DISPLAYS... [Pg.81]

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