HOW TOUCH SCREEN WORKS
There are three technologies in the touch screen display. These technologies are combined all on the top of each other. When you using smart phone first time we are thinking we are holding something revolutionary or something different from previous phones. These are not new technology may device used tactile interface and caller displaced already standard from most phones. Even toughened glass discovered in 1800 innovative element was combining them senselessly one layer top of the other like a magic.Get More Electrical Concept And Interview Questions By Using This Link
On the top it having a protective glass lot of us have a screen shader but how many times you dropped it and hasn’t. The smart phone glasses five times stronger than the normal glasses. First before iPhone stood up in 2007 standard screen in plastic. Plastic shouldn’t shader it will easily scratch. If the screen will covered in plastic it wouldn’t last a week in sitting in a pocket next your keys performing doesn’t due to scratch all over the screen. This makes the toughened glass so stronger.
Smart phone glass is a luminous glass that is toughened by soaking by path of potassium nitrate.
This causes the sodium atoms in the glass to migrate out and much layer potassium atoms to take their place because the potassium atoms are much larger they generally a substantial compressive force on the surface of the glass.
There is a quick analogy imagine filling back seat of the car is a three average sized people they fixed constantly but if we push them still able to move. Now place those three peoples with very big sizes even they can’t able to move. For moving it required more forces. This is the fundamental concept behind the toughened glass special. The atoms are compressed it will take much more force to break.
Below the toughened glass the protected capacitive touch screen that senses the presence and location of conductive material such as fingertip. This touch screen is composed of two transparent diamond create patterns printed on polyester within optically clear insulator in the middle.
The diamond create pattern is printed in the transparent material called indium tin oxide or ITO which acts as a conductor.
Let’s see briefly how it works.
We build a bunch of electrons on the blue diamond because there is an insulator in the way the electrons cannot move.
Electrons generate negative charges to build up in the yellow diamond.
This is called capacitor when we move conductive material such as the finger close to the capacitor it sucks the electric field which changes the amount of positive charges that build up the yellow diamond.
The change in the positive charges in yellow diamond is measured in the process. They registered as touch location of touch detected by the skinny charges or voltage along the blue diamond column. Each blue diamonds connected together also each column yellow diamond is connected.
This setup makes the blue column and yellow rows. All these materials are made by transparent materials measuring each point required too much circuity so we measure only columns. The charge or voltage gets senses each row in quick session so the processor can register multiple touches at once.
Below the display which uses the LCD OR Organic LED well the LCD and OLED both produces high quality emission.
Here we are going to see about OLED because most of the smart phones uses this technology. This is high resolution LED. This is the crazy inter-grid 2080 high end phone has a over 3.3 million pixels. That means 10 million microscopic individual control the dimmable red, green and blue light in form of your hand LED displays are composed of massive creative of individual pixels and unit pixels red, green and green sub pixel each sub pixel light intensity controlled by a small transistor that acts as a dimmer switch. There are many layer structure in each sub pixel photons are produced sub pixels by electrons driven from the negative so that positive terminal when they pass through metal layer is called emissive layer.
Photons are immediate release through the energy the compounds used to make of the emissive layer to determine the colour of the layer emitted and this intensity of the layer is depend upon the how many electrons passes.