What Is An LCD Display? How does it work? Explained

People have always wondered what difference there is between LCD and LED type displays, so today we are going to identify and discuss some of the key differences between them.

LCD Display

LCD stands for Liquid Crystal Displays, and was first invented in 1968 which made a whole new generation of displays from then. It was introduced by George H. Heilmeier at that time. LCDs are widely used in devices like TVs, smartphones, monitor's, computers etc.

LCDs work by using liquid crystals sandwitched between two transparent electrodes and polarizing filters. These crystals are not able to emit light on their own, instead the crystals twist and untwist thereby controlling the amount of light that should enter through them. When the crystals twist to one side the screen turns black, and when it turns to another side the screen turns white and bright. The liquid crystals are basically the heart of the display, controlling the light passage. Light source in this is the backlight which is often CCFL or LED, which shines through the crystals and the crystals change direction of light to form the image required. Every pixels that is there in the screen is divided into other three sub-pixels that is; red, green, and blue. These three colours are also called RGB. By adjusting the brightness of each pixel we can create any shade of a colour we want.

Microscopic image of LCD display 

The advantages of LCDs are that they are very thin and lightweight compared to other older displays, consumes less power compared to old CRT screens, provides sharp and vibrant colours and images, LCD TVs are often really cheap and inexpensive, and the other surprising feature that it does not emit light on themselves, and simply relies on the backlight.

Backlight of LCD display

There are also few disadvantages of LCDs. If you are watching something on an LCD monitor and you are looking at the screen in a low angle, you will see that the screen is darker, thus giving us limited viewing angles. The major disadvantage on LCDs are that they struggle to produce true black colours. On LCDs the black spot on the screen stays lit up, producing a dark blue colour on the area where it is supposed to be black. Prolonged exposure to LCDs may cause retinal photoreceptor cell damage, damaging our eyes which causes headaches, potential retinal damage and sleep disruption. So, it is best for us to take a break if you are infront of the screen for too long. However this problem can be solved by using blue light filters which reduces the amount of blue light entering our eyes.