This document provides an overview of touch screen technology, including: - A brief history starting with the first touch screen developed in 1971 and key developments since then. - The main components of a touch screen including the touch sensor, controller, and software drivers. - The main types of touch screen technologies - resistive, capacitive, and infrared. - The advantages and disadvantages of each technology. - Common applications of touch screens including mobile phones, tablets, ATMs, and more.

1. Submitted by: Mamta
Information technology
3rd year (6th semester)

2. Table of contents:
Introduction
History and Development
Working and Main components
Types of Touchscreens
Pros and cons
Application
Conclusion

3. Introduction:
 A touch screen is an electronic visual
display that can detect the presence and
location of a touch within the display area.
Touch screens can sense Finger and other
passive objects, such as a stylus.
 A touch screen accepts direct onscreen
inputs.

4. History & Development:
 In 1971 Dr. Sam Hurst, founder of Elographics developed
the first touch opaque sensor “Elograph” at the
University of Kentucky.
 In 1974 He developed the first real touch screen.
 In 1977, Elographics developed the five-wire resistive
technology then with the backing of Siemens
Corporation, developed a curved glass sensor called the
touch screen.
 The new transparent technology, AccuTouch, was later
developed by the founders of Elographics, Dr. Hurst and
Bill Colwell.
The father of the touch
screen technology

5. Touch sensor:
 A touch screen sensor is a clear glass panel
with a touch responsive surface.
 The sensor generally has an electrical
current or signal going through it.
 Voltage change determine the point of
touch.
Main components:
 Touch sensor
 Controller
 Software Driver

6. Controller:
 The controller is a small PC card that connects between the touch sensor and the
PC..
 The controller determines what type of interface/connection you will need on the
PC
 It takes information from the touch sensor and translates it into information that
PC can understand.

7. Software Drivers:
 The driver is a software that allows the touch screen and
computer to work together
 Most touch screen drivers today are a mouse-emulation
type driver.
 It tells the operating system how to interpret the touch
event information that is sent from the controller.

8. Types of touch screen technology:
Resistive
Capacitive
These are of 2 types:-
Surface Capacitive
Projected Capacitive
Infrared

9. Resistive Touchscreen:
 A resistive touch screen panel is composed of several layers,
the most important of which are two thin, metallic, electrically
conductive layers separated by a narrow gap.
 The resistive touch screen uses a glass panel with a uniform
conductive ITO(Indium Tin Oxide) coating on the side surface.
 A PET film is a tightly suspended over the ITO coating surface
of a glass pane
 When an object, such as a finger, presses down on a point on
the panel's outer surface the two metallic layers become
connected at that point.
 This causes a change in the electrical current, which is
registered as a touch event and sent to the controller for
processing.

10. Advantages: Disadvantages:
 Works well with nails or
stylus input.
 Generally most affordable
touchscreen technology.
 Rugged/Durable
 Tolerates dust/dirt, rain
and insects.
 Liquids won't affect touch
screen performance.
 Not as accurate
 Multi-touch much more
complex.
 Usually no discretion
between stylus and hand.
 More pressure needed
 Conductive coating
reduces display
brightness.

11. Capacitive Touchscreen:
 It is an all glass touch screen with a transparent
metallic conductive coating of ITO(Indium Tin Oxide).
 In the capacitive system, a layer that stores electrical
charge is placed on the glass panel.
 A human body is an electric conductor, so when
touched the screen with a finger, a slight amount of
current is drawn, creating a voltage drop.
 This decrease is measured in electrodes located at
four corner of the monitor.
 The computer then calculates the coordinates, from
the relative differences in charge at each corner.

12. Surface capacitive :
 It consists of uniform conductive coating
on one side of the glass panel.
 Electrodes around the panel edge evenly
distribute a low voltage around the
conducting layer.
Projected capacitive touch
 Two parallel ITO layers
 Two sheets of glass
 It have front and protective glass to provide
additional optical and strength enhancements
options.

13. Advantages: Disadvantages:
 It has high resolution and
Image clarity.
 Immune to surface
contaminants like dirt,
grease or moisture.
 Durable and resistant to
scratches.
 Will work only when
touched by a conductive
device.
 Some capacitive touches
can have erratic behavior
when touched by more
than one input.

14. Infrared Touchscreen :
 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 the
pattern of LED beams.
 A process by which light is trapped
within a medium and can be interrupted
by a third medium of higher reflective
index to cause light to escape.

15. Advantages: Disadvantages:
 It can detect essentially any
input including a finger,
gloved finger, stylus or pen.
 It have better durability
and optical clarity.
 Higher accuracy than other
technologies.
 It is sensitive to dirt/dust
that can interfere with the
IR beams.
 It suffer from parallax in
curved surfaces and
accidental press
 Low resolution

16. Over All pros and cons of Touchscreen:
Advantages:
 Direct pointing to the objects.
 Fast response
 Use finger, fingernail, gloved hands,
stylus or any soft tip pointer.
 Easy to clean
 Does not require mouse and
keyboard
 Make computing easy , powerful
and fun.
Disadvantages:
 Low precision by using finger
 User has to sit or stand closer to the
screen
 The screen may be covered more by
using hand.
 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.

17. Application:
Mobile phones ,tablets & Laptops, Tourism displays, Trade show display,
Stores, Market research Restaurants, ATMs, Banks, Airline ticket terminals and
Transportation hubs. Computerized gaming, Student Registration systems,
Multimedia software , Scientific applications, Industrial and Medical
instrumentation etc.
Conclusion:
Though the touch screen technology contains some limitations it’s very
user friendly, fast, accurate, easy for the novices & fun to operate. It has
been widely accepted. And now by just modifying a little it can replace
the mouse and key board completely in near future.