There is always a major confusion when people think about LEDs that are being used in the mass market. LEDs ( Light emitting diodes ) are fascinating things in the field of electronics. Before i go in depth, just know that LEDs emit light in the form of photons generated from the phenomenon called electroluminescence. If you are good in physics, get this – light energy is emitted when an electron travels in a p-n junction diode.
Enough of physics, let’s get to the market perspective. Usually, when somebody mentions LEDs, inadvertently we think of LED tvs and the LED displays on mobile phones. You may argue, LEDs are not only used in TVs and mobile phones, they are used in LED Neon Flex boards and of course, in christmas decorations that you buy from your nearby LED Shop. But did you know that each LED is somewhat different in it’s usage ?
Other than commercial LEDs, did you know that LED TVs and LEDs that are present in mobile phones are completely different ?
Well, yes, they are indeed completely different. I will explain the difference in an easy manner.
First take a look at the normal LEDs in a LED tv. A LED tv is actually a LCD panel with LED backlighting. NOrmal LEDs are arranged in an array and are made as the source of light for the LCDs. Previously they used to use incandescent light bulbs, normally fluoroscent tubes. They used to provide lighting for the LCD panels, but since the arrival of LEDs, they are used instead. The use of LEDs helps in reducing the overall footprint on the TV’s volume and also saves a lot of power.
In a nutshell : LED Tvs use normal LEDs for their backlight which are arranged in an array. ( Array types – Edge lit, Full array )
Now, coming to mobile phone displays, its completely a different scenario. For ages, since black and white displays, normal LEDs have been used to light up the puny LCD TFT panels that mobile phones used to have. But, a different technology arrived, that still rivals high quality LCD panels in their lighting technique and color rendition. They are called AMOLED display panels. Originally made famous by Samsung on their Omnia range of smartphones. Omnia HD was the first smartphone in the world to get a AMOLED display. It provided rich colors and amazing brightness.
But how is it different from normal LEDs ?
Basically think of the AMOLED screen as a sandwich, there are two electric plates, one needs to be transparent. In between those two plates, organic electroluminescence material is applied. When current flows through the plates, light is emitted from the organic material. This is called an Organic LED. Take this Organic LED, use it in a matrix array, you get the Active matrix OLED, that is called as the AMOLED display. There are two types of arrays here – RGBG ( called Pentile matrix ) and the original RGB AMOLED.
Hope you were able to capture the difference between a normal LED based application and the OLED based application.
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