LCD Displays History & Technology
Blaze Display Technology Co., Ltd. | Updated: Nov 27, 2018
LCD screen technology is rather straightforward: LCD monitors are made of a substance that is permanently in a liquid state but has some properties inherent in crystal bodies.
A Liquid crystal display is a passive device, which means it doesn't produce any light to display characters, images, video and animations. But it simply alters the light traveling through it. The internal construction of LCD describes how the light altered when it passes through it in order to produce any characters, images etc.
A bit about history
The American inventor J. Fergason created the first working liquid crystal display in 1970. Before that, such devices consumed too much energy, their operating life was limited, and the contrast of the image was on a low level. A new LCD monitor was introduced in 1971. Despite the fact that liquid crystals were discovered a long time ago, at first, they were applied for different purposes. Molecules of liquid crystals under the influence of electricity can change their orientation and, as a result, change the properties of the light beam passing through them. Based on this discovery and because of further research, it became possible to discover a connection between the increase of electric voltage and the change in the orientation of the crystal molecules to ensure the creation of the image. Firstly, liquid crystals found their application in the displays for calculators and quartz watches, and then they were utilized in monitors. Today, due to progress in this area, such screens have become very popular in desktop computers and many other devices.
LCD display technology
LCD screens are an array of small segments called pixels, which can be manipulated for information displaying. Such displays have several layers, where two panels, made of glass material free of sodium and called substrate, play a crucial role. The substrate contains a thin layer of liquid crystals between them. The panels have flutes that direct the crystals, giving them a distinctive orientation. Flutes are parallel on each panel but are perpendicular between the two of them. Longitudinal flutes are obtained as a result of placing on the glass surface thin films of transparent plastic, which are then processed in a particular way. In contact with the flutes, the molecules are oriented identically in all the cells. The liquid crystal panel is illuminated by a light source, depending on where it is located, as the LCD panels operate on reflection or light transmission. The plane of polarization of the light beam is rotated by 90° as one panel passes. When an electric field appears, the molecules are partially aligned along it, and the angle of rotation of the plane of polarization of light becomes different from 90°. By producing screens using LCD monitor technology, the backlight of the monitor is used to output a color image so that light is generated at the back of the LCD monitors. It is necessary to be able to have a picture with good quality, even if it is dark. The color is obtained using three filters, which distinguish three principal components from the radiation of a white light source. By combining the three primary colors for each pixel of the screen, you can reproduce any color.
LCD technology comparison: then-and-now
Modern LCD screens are also called flat panels, dual scan active matrix, and thin-film transistors. Now they are extremely popular - everyone likes their elegant look, thinness, compactness, and efficiency. LCD monitors provide a quality contrast, and bright, clear images. In the past, liquid crystal technology was slow, not as efficient as now, and their contrast level was low. The first matrix technologies, the so-called passive matrices, worked quite well with textual information, but with a sharp change in the picture, so-called “ghosts” appeared on the screen. Since LCD technology orients each pixel separately, the clarity of the received text is higher in comparison with CRT monitors, which in the past could compete with LCD ones. Now, of course, with the development of technology and taking into account the overall technological process, liquid crystal monitors have long been ahead and occupy a leading position among the displays used for various applications. Monitors based on liquid crystals are widely utilized not only in desktop computers but also in an array of electronic devices: TVs, photo and video cameras, laptops, tablets, smartphones, car navigators, e-books, MP3 and other players, watches, etc.