The document discusses touchscreen technology, highlighting its historical development, main components, construction methods, and various types such as resistive, capacitive, and infrared. It emphasizes the user-friendly nature of touchscreens, their advantages and disadvantages, and their widespread applications in public and business settings. The conclusion notes the increasing adoption of touchscreens as a simpler method of input for users of all abilities, suggesting they may eventually replace traditional input devices.

1. TOUCHSCREEN
TECHNOLOGY
BY :-
Ritanshu Goel

3. INTRODUCTION
A touchscreen is a display that can
detect the presence and location of
a
touch within the display area.
The term generally refers to touch or
contact to the display of the
device by

4. The touchscreen has two main attributes:
1. It enables one to interact with what is
displayed directly on the screen, where it
is displayed, rather than indirectly with a
mouse or touchpad.
2. It lets one do so without requiring any
intermediate device, again, such as a
stylus that needs to be held in the hand.
Such displays can be attached to
computers or, as terminals, to networks.

5. History
 The first touch screen was a capacitive
touch screen developed by E.A. Johnson at
the Royal Radar Establishment, Malvern, UK.
The inventor briefly described his work in a
short article published in 1965 and then
more fully - along with photographs and
diagrams - in an article published in 1967.
 One of the first places where they gained
some visibility was in the terminal of a
computer-assisted learning terminal that
came out in 1972 as part of the PLATO
project.
 The HP-150 from 1983 was probably the
world's earliest commercial touchscreen
computer.

6. Development
• The development of multipoint
touchscreen facilitated the tracking of
more than one finger on the screen,
thus operations that require more than
one finger are possible.
• These devices also allow multiple users
to interact with the touchscreen
simultaneously.
• With the influence of the multi-touch-
enabled iPhone and the Nintendo DS,
the touchscreen market for mobile
devices produced 5 billion in 2009.

7. Touch screen technology
Main touch screen components:
1 Touch sensor
2 Controller
3 Software driver
7

8. TOUCH SENSOR .
A touch sensor is a clear glass panel with a touch responsive
surface .
The sensor generally has an electrical signal going through it and
touching the screen causing a signal change.
The signal change is used to determine the location of the touch to the
screen.

9. CONTROLLER
 The controller is
small PC card that
connects between
the touch sensor
and PC.
 It takes information
from the touch
sensor and translate
in to information that
PC can understand.

10. SOFTWARE DRIVER
The driver is a software that allows the
touch screen and computer to work
together.
It tells the operating system how to
interpret the touch event information that
sent from the controller.
Most of the touch screen drivers today
are mouse emulation type driver .

11. Construction
There are several principal ways to build a touchscreen:
• In the most popular techniques, the capacitive or resistive
approach, manufactures coat the screen with a thin,
transparent metallic layer.
• When a user touches the surface, the system records the
change in the electrical current that flows through the
display.
• Dispersive-signal technology which 3M created in 2002,
measures the piezoelectric effect — the voltage generated

12. TYPES OF TOUCHSCREEN
 Resistive Touch screen
 Surface wave Touch screen
 Capacitive Touch screen
*Surface capacitive
*Projected capacitive
 Near Field Imaging Touch screen
 Infrared Touch screen
12

13. Technologies
The types of technologies that can be found are as
follows:
Resistive:
● 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 panel.

14. Working Principle:
● When the screen is touched, it pushes the conductive ITO
coating on the PET film. That results the electrical contact,
producing the voltages. It presents the position touched.
● Resistive touchscreen deliver cost-effective, consistent and
durable performance

15. • On the pure glass substrate,
Surface Acoustic Wave:
there are four piezoelectric
transmitting and receiving
transducers on the three
corners for both the X and Y
axes.
• The SAW controller sends a 5
MHz electrical signal to the X-
axis and Y-axis transmitting
transducers.
• When the touchscreen is touched, the finger absorbs a
portion of the wave passing across the surface of the
panel.
• SAW can be used in any and all applications for the
best possible image clarity an unlimited life.

16. Capacitive:
• Capacitive touchscreen is a four multi-layer glass.
• Small amount of voltage is applied to the electrodes on
the four corners
• 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. The current
respectively drifts to the electrodes on the four corners.
• The capacitive system has very long life (about 225

17. Infrare
d:
● Conventional optical-touch systems
use an array of infrared (IR) light-
emitting diodes (LEDs) on two
adjacent bezel edges of a display, with
photosensors placed on the two
opposite bezel edges to analyze the
system and determine a touch event.
• IR eliminates the use of glass or plastic overlay that
most other touch technologies require in front of the
display.
• High cost of the technology.
• IR increases the noise floor at the optical sensor

18. Technology Capacitive SAW Infrared Resistive
Transparence Very good Very good Very good 75%~85%
>92% >92% >92%
Resolution Good Good Limited due to good
spacing of IR
sensors
Surface Resistant to Adversely Potential for Unaffected by
Contaminants moisture and affected by False activation Surface
/durability other surface moisture or or dead zones contaminants.
contaminants Surface From Surface Polyester top
contaminants Contaminants sheet is easily
scratched
Sensor substrate Glass with ITO Glass with ITO Any substrate Polyester top
coating coating sheet, glass
substrate with
ITO coating
Display size 8.4"-21" 10.4"-30" 10.4"-60" up to 19"
Touch method Human touch finger, gloved Can use any Can use any
pointing device pointing device
hand or soft tip

19. Advantages &
Disadvantages:
Advantages:
• User friendly.
• Fast response.
• Error free input.
• Easy to install.
• Use finger, fingernail, gloved hand, stylus or any
soft-tip pointer to operate.
• Easy to clean and maintain.
• Compatible with Windows, Macintosh and Linux.
• Does not interfere mouse and keyboard function.
• Make computing easy, powerful and fun.

20. Disadvantages:
1)Finger stress: Stress on human fingers when used
for more than a few minutes at a time. (for example,
ATMs).
2)Fingerprints: Touchscreens can suffer from the
problem of fingerprints on the display.
3)User has to sit closer to the screen as compared to
external keyboard.
4) The screen may be covered more by using hand.

21. Applications
Public Access:
• Mobile Phones
• Library resource guides
• Computers
• Public Transportation Schedule /
Status
• Airport terminal passenger internet
and email systems
• Automated travel and entertainment
ticket dispensers

22. Business
• Gas stations
• Point of sales
• Restaurants
• Grocery stores
• Hospital and hotel directories
(check-in, registration)
• Banks and Financial Reporting
• Bank cash advance and teller
machines

23. Conclusion:
• Designers are trying to use touchscreen to
simplify input commands for largely
unsophisticated computer users.
• Today, a larger share of population is PC literate,
yet the touchscreen has become adopted by
computer users of all abilities because it is
simple, fast, and innovative.
• In future there is no usage of mouse and
keyboards as they will be replaced by
touchscreens.