If you’ve ever wondered how the LCD module works, then you are not alone. Millions of electronic users who use devices with a liquid crystal display don’t have an idea of what its function is or how it operates. But I can tell you it is not magic but pure science. So just in case you are one of them, here is how the LCD works.
How it Works
The technology behind liquid crystal display is not a new one, and it has been in existence since the advent of calculators, wristwatches, and large television sets. The only difference is that there has been a massive upgrade to the entire outlook of these displays. Before, it was common to find TVs with display units that produce a lot of heat, and this was mainly due to how the display picture was generated. Older models made use of cathode-ray tubes that light up once current passes through the filament.
But the latest models of TVs make use of flat screens without the need for large fluorescent tubes that make them weigh a lot less than the older models. The secret behind the clear pictures of LCD screens without the heat is how the light is blocked. The liquid crystal display comprises two substrates, also known as polarized glass. And in between these substrates is a liquid crystal material.
A backlight forms the light that moves through the first substrate, and simultaneously, as current passes through, the molecules of the liquid crystal bind together to allow different ranges of light to get through to the second substrate, which results in the images and colors that you see.
This video gives a vivid explanation.
In the case of TFT LCD
The secret behind how TFT LCD display works is with the help of an active matrix technology. The thin-film transistor places the tiny capacitors and conductors in a matrix on the display screen. To be able to produce a particular pixel, the appropriate row is turned on, and an electric charge passes down the specified column. Since the rest rows are off and idle, only the specified pixels receive the charge.
As you already know, there are three states of matter, solid, liquid, and gas. While it is impossible to change the molecules to a solid-state, the liquid molecules can be altered to move about. And this is why liquid molecules are easily affected by temperature. This is why you may find difficulties with your computer display when in extreme weather.
The native resolution present in LCD is what makes the monitors display their designed resolution, unlike in the case of cathode-ray tubes. All other features such as response rate, adjustability, and contrast ratio are all enhanced with LCD. When it comes to luminance or brightness, the rating range differs, and for monitors that perform a varying degree of tasks like the microwave and watches, a rating of 250 to 350 could get the job done. But for much higher ratings for more explicit pictures in the case of TVs and mobile phones that show picture quality in HD, you need a rating of 500 candelas per meter square cd/m2.