touch screen technology



Capacitive touch screen: The capacitive touch screen is made up of a glass panel that is coated with a material.
The property of this material is that it can store electrical charge. So the capacitive touchscreens basically stores electrical charge.
But for good, Human body can also store charge. So, when you touch this screen with your finger, some of these charges on the screen gets transferred to your finger. The oscillator circuits located at the corner of your system will then sense this decrease in the charge on screen and the spot the exact location where touch occurred, and then transfers this specified information to the touchscreen driver software.


Pros:
Multi touch support available
Visibility good even in sunlight
Highly sensitive to finger touch leading to ease of use
Not prone to dust particles
Glossy look and feel

Cons:
Need to have atleast 5% humidity to achieve capacitive effect
More expensive than Resistive touch screen
Doesn't work with inanimate objects/fingernails/gloved fingers
Latest technology, may need to evolve a bit more!





Resistive touch screen: Resistive touch screen, on the other hand is again made up of normal glass panel. However, this glass panel in this case is coated with three layers.
Two of these layers () being conductive and resistive are kept apart using spacers while the third scratch-resistant layer covers the whole setup
When the resistive touch screen system is running, current flows through these layers. On a finger touch, the two layers get connected and change in electrical field occurs. The system calculates the coordinates of point of contact and passes them to touch screen driver software.
It is made of two resistive layers opposing each other with a conducting transparent material call Indium tin oxide (ITO). ITO has 100 – 500 ohm sensitivity per sq. m

Pros:
Relatively cheaper
Can operate with any pointing devices like stylus, pen, nail etc
Can operate at any level of humidity
Ease of use, as it could be used even with your winter gloves on!
Very useful for people using handwriting recongition system, due to ease of use with a stylus!
More accurate than capacitive touch screen!
Old technology and hence more reliable!


Cons:
Multi touch support not available. Though technology did evolve after some modifications with the existing resistive touch screen circuitry, its still not 100% developed yet!
Highly sensitive. As it can operate with almost any sort of pointing devices, can be more vulnerable with dust particles!
Poor visibility in sunlight, mostly due to multiple layers reflecting light!
Screen, being sensitive at the upper layer, can be more vulnerable to scratches!


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