LED Screens – for TV, Computer and other Displays are common now. Have you ever wondered how it is able to produce all colours (and their variants) in the colour spectrum? Let us see how this is achieved
RGB – The Primary Colours
We all know that Reg, Green and Blue are called the Primary Colours and from these three we derive all other colours. With Additive and Subtractive mixing methods explained in the article Colour Mixing Basics we create all other colours.
In the LED Screens, we have several Tiny LEDs (Light Emitting Diodes), which are electronic components. These LEDs emit light when current passes through them.
The Human Eye has Receptor Cells known as Cones that detect light. Three different types of Cone Cells are there in the Retina, which detect Red, Green and Blue light.
We see colours depending upon the amount of light falling on the Cone Cells and the proportions of Red, Green and Blue light. See the Additive Colour Mixing for the combinational colours produced by these Primary Colours.
The LEDs on the LED Screens are tiny LEDs producing the Red, Green and Blue lights. By combining these colours in appropriate proportions, the screen produces all colours. The absence of any colour creates a black and equal mixing of RGB produces White Colour. In effect, the screen is tricking our eyes into seeing the different colours. So, if all LEDs are switched ON, they produce White Light and when Switched OFF they produce Black Colour. The Electronic Circuitary inside the screen does all this mixing.
LEDs are relatively cheap and hence find use in majority of the display devices. They require only very low power and produces only minimal heat. Hence they are eco-friendly to certain extent.