A touchscreen is an
electronic visual display that the user can control through simple or
multi-touch gestures by touching the screen with one or more fingers. Some
touchscreens can also detect objects such as a stylus or ordinary or specially
coated gloves.
Touchscreens are common in
devices such as game consoles, all-in-one computers, tablet computers, and
smartphones. They also play a prominent role in the design of digital
appliances such as personal digital assistants (PDAs), satellite navigation
devices, mobile phones, and video games.
Working of Touch Screen Are
very Interesting. Here's How they Work:
There are three basic
systems of Touch Screen:
1. Resistive System
2. Capacitive System
3. Surface Wave acoustic
The RESISTIVE SYSTEM
consists of a normal glass panel that is covered with a conductive and a
resistive metallic layer. These two layers are held apart by spacers, and a
scratch-resistant layer is placed on top of the whole setup. An electrical
current runs through the two layers while the monitor is operational. When a
user touches the screen, the two layers make contact in that exact spot. The
change in the electrical field is noted and the coordinates of the point of
contact are calculated by the computer. Once the coordinates are known, a
special driver translates the touch into something that the operating system
can understand.
Working Of Resistive Touch
Screen !!!
In the CAPACITIVE SYSTEM, a
layer that stores electrical charge is placed on the glass panel of the
monitor. When a user touches the monitor with his or her finger, some of the
charge is transferred to the user, so the charge on the capacitive layer
decreases. This decrease is measured in circuits located at each corner of the
monitor. The computer calculates, from the relative differences in charge at
each corner, exactly where the touch event took place and then relays that
information to the touch-screen driver software. One advantage that the
capacitive system has over the resistive system is that it transmits almost 90
percent of the light from the monitor, whereas the resistive system only
transmits about 75 percent. This gives the capacitive system a much clearer
picture than the resistive system
The SURFACE WAVE ACOUSTIC
SYSTEM works with help of wave energy. This enables a touch to transform into
another form of energy and deliver the command which in response perform the
desired action. A Pair of transducers is placed on glass plate sides. In the
Glass Plates there are reflectors. On touching the screen wave produced and
which transforms into energy for fulfilling the command. It tells where on the
screen touch is detected.
