This image is then displayed on the screen. An LCD is either made up of an active matrix display grid or a passive display grid. Most of the electronic devices mainly depend on liquid crystal display technology for their display.
The liquid has a unique advantage of having low power consumption than the LED or cathode ray tube. The liquid crystal display screen works on the principle of blocking light rather than emitting light. LCDs require a backlight as they do not emit light them. Cathode ray tube draws more power compared to LCDs and is also heavier and bigger.
As mentioned above that we need to take two polarized glass pieces filter in the making of the liquid crystal. The glass which does not have a polarized film on the surface of it must be rubbed with a special polymer that will create microscopic grooves on the surface of the polarized glass filter.
The grooves must be in the same direction as the polarized film. Now we have to add a coating of pneumatic liquid phase crystal on one of the polarizing filters of the polarized glass. The microscopic channel causes the first layer molecule to align with filter orientation. When the right angle appears at the first layer piece, we should add a second piece of glass with the polarized film.
The first filter will be naturally polarized as the light strikes it at the starting stage. Thus the light travels through each layer and guided to the next with the help of a molecule.
The molecule tends to change its plane of vibration of the light to match its angle. When the light reaches the far end of the liquid crystal substance, it vibrates at the same angle as that of the final layer of the molecule vibrates. The light is allowed to enter into the device only if the second layer of the polarized glass matches with the final layer of the molecule. The principle behind the LCDs is that when an electrical current is applied to the liquid crystal molecule, the molecule tends to untwist.
This causes the angle of light which is passing through the molecule of the polarized glass and also causes a change in the angle of the top polarizing filter. As a result, a little light is allowed to pass the polarized glass through a particular area of the LCD. Thus that particular area will become dark compared to others. The LCD works on the principle of blocking light.
While constructing the LCDs, a reflected mirror is arranged at the back. An electrode plane is made of indium-tin-oxide which is kept on top and a polarized glass with a polarizing film is also added on the bottom of the device.
The complete region of the LCD has to be enclosed by a common electrode and above it should be the liquid crystal matter. Next comes the second piece of glass with an electrode in the form of the rectangle on the bottom and, on top, another polarizing film. It must be considered that both the pieces are kept at the right angles.
When there is no current, the light passes through the front of the LCD it will be reflected by the mirror and bounced back. As the electrode is connected to a battery the current from it will cause the liquid crystals between the common-plane electrode and the electrode shaped like a rectangle to untwist.
Thus the light is blocked from passing through. 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 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.
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. Without any voltage applied between transparent electrodes, liquid crystal molecules are aligned in parallel with the glass surface. When voltage is applied, they change their direction and they turn vertical to the glass surface.
They vary in optical characteristics, depending on their orientation. Therefore, the quantity of light transmission can be controlled by combining the motion of liquid crystal molecules and the direction of polarization of two polarizing plates attached to the both outer sides of the glass sheets. LCDs utilize these characteristics to display images. Working principle of an LCD.
An LCD consists of many pixels.
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