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Touch Screen
Technology
Noor Al-Nassar
Overview :
Introduction
History
Components
Technologies
Pros & Cons
Applications
Conclusion
Introduction :
- A touch screen is a display that can detect the presence and location of a touch within the display area.
- Touch screen can also sense other passive objects such as
stylus.
History :
- Touch screen emerged from academic and corporate
research labs.
- In 1971 , the first touch sensor was developed by Doctor Sam Hurts ( founder of Elographics ) while he was an
instructor at the University of Kentucky.
- This sensor, called the “Elograph”.
- Touch screen first gained some visibility with the invention
of the computer-assisted learning terminal, which came out
in 1975 as part of the PLATO project.
components :
A basic touch screen has three main components :
- Touch sensor.
- Controller
- Software drive.
Touch sensor :
- A touch screen sensor is a clear glass panel with a touch
responsive area.
- The touch sensor is placed over a display screen so that the
responsive area of the panel covers the viewable area of the
screen.
Controller :
- The controller connects between the touch sensor and PC. -
- Take information from the touch sensor and translate it into
information that PC can understand.
Software drive :
- The drive allow the touch screen and computer to work together.
- This makes touching the screen as same as clicking the
mouse at the same location on screen.
Technologies:
- Resistive
- Surface acoustic wave
- Capacitive
- Infrared
- Optical imaging
Resistive :
- Composed of several layers.
- Two Electrically conductive layers.
Surface acoustic wave :
- Uses ultrasonic waves.
- Surface wave touch screen panels can be damaged by outside elements.
- When the panel is touched, a portion of the wave is absorbed.
Open frame SAW Touch
Monitor
Capacitive :
- Consist of an insulator such as glass.
- Coated with transparent conductor such as ITO
(Indium Tin Oxide) .
- Touching the surface of the screen results in a distortion of
screen’s electrostatic field, measurable as a change in
capacitance.
Infrared :
An infrared touch screen uses an array of X-Y infrared LED
and photo detector pairs around the edges of the screen to
detect a disruption in pattern of LED beams.
Optical imaging :
In this two or more image sensor are placed around the edges
of the screen. A touch shows up as a shadow and each pair
of camera can then be pinpointed to locate the touch.
Comparison :
PROS
&
CONS
PROS :
- User friendly.
- Fast response.
- Error free input.
- Use finger, fingernail, gloved hands, stylus or any soft tip
pointer.
- Easy to clean.
- Does not interfere mouse and keyboard.
- Make computing easy, powerful and fun.
-It benefit children.
CONS :
- Finger stress.
- Fingerprints.
- Screen has to be really big not to miss things when pressing
them with your finger.
- Big screen leads to low battery life.
- Touch screen means screen can’t be read too well in direct
sunlight as it applies an additional not 100% transparent.
- Fatigue.
Applications :
- Museums.
- Cell phones .
- Library recourse guides.
- Corporate information.
- Airport terminal passenger internet and emails.
- ATM’s.
- Restaurants'.
Conclusion :
- Designers are trying to use touch screen to simplify input
commands.
- Today, touch screen has becomes adopted by computers
users of all abilities because it is simple, fast and
innovative.
- In future there is no usage of mouse and keyboard as they
will be replaced by touch screen.
References :
http://en.wikipedia.org/wiki/Touchscreen
http://www.google.com.sa/search?q=touch+screen&um=1&h
l=ar&safe=active&gbv=2&tbm=isch&ei=psDeUJevLq2T0
QWS44C4Dw&start=240&sa=N
http://www.touchwindow.com/c/TouchScreens.html