Twisted Nematic TN

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

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]

Lehmann postulates 1971 Schadt and Helfrich describe LCs as the 4th state the twisted nematic (TN) cell... [Pg.48]

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]

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]

Figure 4.6 Working principle of a twisted nematic (TN) cell in the normally white" configuration (left), and the change of transmission with increasing applied voltage (right). In the cell configuration sketched above the threshold voltage (V,, ) for the electrooptical response corresponds to approximately V90 for 90% of maximum transmission.

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]

A noteworthy feature of the twisted nematic (TN) is that the intensity of... [Pg.109]

In LCDs various LC modes of operation are applied like twisted nematic (TN) [5], super twisted nematic (STN)[6], vertically aligned nematic (VAN) [7,8], optically compensated birefringence (OCB) [9] and in plane switching (IPS) [10-12]. The LC mode used depends on the demands of a specific application, like the viewing angle, power consumption and manufacturing cost. [Pg.132]

In Fig. 9.2 the switching behaviour of a twisted nematic (TN) LCD is depicted. Figure 9.2a shows a TN LCD in the off-state. The light coming from the bottom is polarised by the first polariser and due to the bire-... [Pg.132]

A twisted nematic (TN) does not by itself exhibit flexo-polarization, but a DC electric field applied normal to the helical axis generates a tilt... [Pg.50]

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]

As we look to the 1980 s a display gap still remains. We show in this paper that the device responsible for the commercial success of LCDs to date, the twisted nematic (TN) LCD, is limited to flat panel displays with less than about 10 independently addressable picture elements (pels). Thus, there is no display technology available today that will provide a low power, flat panel display with high information content (10 to 10 pels). [Pg.79]

The twisted nematic (TN) is the prototype LCD. Its structure and operation are worth comprehending in detail... [Pg.100]

Positive Ae LCs have been used in twisted nematic (TN) [31] and in-plane switching (IPS) [32,33] displays, although IPS can also use negative Ae LCs. For thin-fUm-transistor (TFT) based displays, the employed LC material must possess a high resistivity [34]. Fluorinated compounds exhibit a high resistivity and are the natural candidates for TFT LCD applications [35,36]. A typical fluorinated LC structure is shown below ... [Pg.202]

The 90° twisted-nematic (TN) cell [3] has been used extensively for notebook computers where viewing angle is not too critical. Figure 8.1 shows the LC director configurations of the normally white TN cell in the voltage-off (left) and voltage-on (right) states. [Pg.236]

Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...